WO2023056759A1

WO2023056759A1 - Internally engaged planetary gear apparatus, and joint apparatus for robot

Info

Publication number: WO2023056759A1
Application number: PCT/CN2022/099417
Authority: WO
Inventors: 王刚; 林文捷; 峯岸清次; 郭子铭; 伊佐地毅
Original assignee: 美的集团股份有限公司; 广东极亚精机科技有限公司; 广东美的制冷设备有限公司
Priority date: 2021-10-05
Filing date: 2022-06-17
Publication date: 2023-04-13
Also published as: JP2023055060A

Abstract

Embodiments of the present disclosure provide an internally engaged planetary gear apparatus, and a joint apparatus for a robot, which can easily reduce the loss generated when an inner pin rotates. The internally engaged planetary gear apparatus (1A) comprises a bearing component (6A), an internal gear (2), a planetary gear (3), a plurality of inner pins (4), a plurality of groups of rolling bearings (41, 42), and a circulation path (170). In a state where the plurality of inner pins (4) are respectively inserted into a plurality of inner pin holes (32) formed on the planetary gear (3), said inner pins revolve within the inner pin holes (32), and simultaneously rotate relative to the internal gear (2). The plurality of groups of rolling bearings (41, 42) respectively hold the plurality of inner pins (4) at two sides of the planetary gear (3) in a direction parallel with the axis of rotation (Ax1). The circulation path (170) comprises gaps between the inner peripheral surfaces of the inner pin holes (32) and the inner pins (4), and rolling paths (404) of rolling bodies (402) in the rolling bearings (41, 42). In the internally engaged planetary gear apparatus (1A), a lubricant is circulated by means of the circulation path (170).

Description

Internal meshing planetary gear units and joint units for robots

Cross References to Related Applications

This application is based on Japanese patent application No. 2021-164157 and application date of October 05, 2021, and claims the priority of this Japanese patent application. The entire content of this Japanese patent application is hereby incorporated into this application as refer to.

technical field

Embodiments of the present disclosure generally relate to an internal meshing planetary gear device and a joint device for a robot, and more specifically, relate to an internal meshing planetary gear device and a joint device for a robot in which a planetary gear having external teeth is disposed inside an internal gear having internal teeth. joint device.

Background technique

As a related art, there is known an internally meshing planetary gear (external gear) in which a planetary gear (external gear) swings and rotates together with the rotation of an input shaft so that a trochoidal tooth-shaped external tooth provided on the outer periphery of the planetary gear meshes with an internal tooth of an internal gear. Gear device (structure) (for example, refer to Patent Document 1). In the related art internal meshing planetary gear unit, the rotation of the input shaft is taken out as the decelerated rotation (autorotation) of the planetary gear by the meshing of the external teeth of the planetary gear and the internal teeth (pins) of the internal gear.

In this internal meshing planetary gear device, an inner pin passing through an inner pin hole (play fitting hole) of a planetary gear is rotatably fitted into a flange portion of an output shaft via a bush. Thus, the rotation of the planetary gear absorbs its swing component through the gap between the inner pin hole and the inner pin, and only the rotation component is transmitted to the output shaft through the inner pin.

prior art literature

patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 05-044790

Contents of the invention

The technical problem to be solved by the invention

In the structure of the related art described above, the output shaft (flange portion) holds the inner pin rotatably via the bushing, but when the inner pin rotates, friction occurs between the output shaft (flange portion) and the inner pin, and this friction may become Loss in power transmission. In particular, when the internal meshing planetary gear device is used for a long period of time, for example, the loss due to friction increases due to deterioration of the lubricant or the like, which hinders the life extension of the internal meshing planetary gear device.

An object of an embodiment of the present disclosure is to provide an internally engaging planetary gear device and a joint device for a robot that easily reduce loss generated when an internal pin rotates.

Solutions for technical problems

An internal meshing planetary gear device according to one aspect of an embodiment of the present disclosure includes a bearing member, an internal gear, a planetary gear, a plurality of inner pins, a plurality of sets of rolling bearings, and a circulation path. The bearing member has an outer ring and an inner ring arranged inside the outer ring, and the inner ring is supported relative to the outer ring so as to be relatively rotatable about a rotation axis. The internal gear has internal teeth and is fixed on the outer ring. The planet gears have external teeth that partially mesh with the internal teeth. The plurality of inner pins are inserted into the plurality of inner pin holes formed in the planetary gear, and rotate relative to the inner gear while revolving once in the inner pin hole. The plurality of sets of rolling bearings respectively hold the plurality of inner pins at both sides in a direction parallel to the rotation shaft with respect to the planetary gear. The circulation path includes a gap between the inner peripheral surface of the inner pin hole and the inner pin and a raceway of a rolling body in the rolling bearing. In the internal meshing planetary gear unit, lubricant is circulated through the circulation path.

A joint device for a robot according to an aspect of an embodiment of the present disclosure includes the internal meshing planetary gear device, a first member fixed to the outer ring, and a second member fixed to the inner ring.

Invention effect

According to the embodiments of the present disclosure, it is possible to provide an internal meshing planetary gear device and a joint device for a robot that easily reduce losses that occur when the inner pin rotates.

Description of drawings

FIG. 1 is a perspective view showing a schematic configuration of an actuator including an internal meshing planetary gear unit according to a basic configuration.

Fig. 2 is a schematic exploded perspective view of the same internal meshing planetary gear device viewed from the output side of the rotary shaft.

Fig. 3 is a schematic cross-sectional view of the same internal meshing planetary gear unit.

Fig. 4 is a sectional view taken along line A1-A1 of Fig. 3 showing the same internal meshing planetary gear unit.

Fig. 5A is a perspective view showing the planetary gears of the same internal meshing planetary gear unit as a single body.

FIG. 5B is a front view showing the planetary gears of the same internal meshing planetary gear unit as a single body.

Fig. 6A is a perspective view showing a bearing member of the same internal meshing planetary gear unit as a single body.

Fig. 6B is a front view showing the bearing member of the same internal meshing planetary gear unit as a single body.

Fig. 7A is a perspective view showing the eccentric shaft of the same internal meshing planetary gear unit as a single body.

Fig. 7B is a front view showing the eccentric shaft of the same internal meshing planetary gear unit as a single body.

Fig. 8A is a perspective view showing the support body of the same internal meshing planetary gear unit as a single body.

Fig. 8B is a front view showing the support body of the same internal meshing planetary gear unit as a single body.

FIG. 9 is an enlarged view showing a region Z1 of FIG. 3 of the same internal meshing planetary gear unit.

Fig. 10 is a sectional view taken along line B1-B1 of Fig. 3 showing the same internal meshing planetary gear unit.

Fig. 11 is a schematic sectional view of the internal meshing planetary gear unit according to the first embodiment.

Fig. 12 is a sectional view taken along line B1-A1 of Fig. 13 showing the same internal meshing planetary gear unit.

Fig. 13 is a side view of the same internal meshing planetary gear unit as seen from the input side of the rotary shaft.

Fig. 14 is a side view of the same internal meshing planetary gear unit as seen from the output side of the rotary shaft.

Fig. 15 is a schematic cross-sectional view showing a state where the cover and the oil seal are removed in the internal meshing planetary gear unit as above.

16 is a side view seen from the input side of the rotary shaft, showing a state where the cover and the oil seal are removed in the internal meshing planetary gear unit as above.

17 is a side view of the internal meshing planetary gear unit as seen from the output side of the rotary shaft, showing a state where the cover and the oil seal are removed.

Fig. 18 is a sectional view taken along line A1-A1 of Fig. 11 showing the same internal meshing planetary gear unit.

Fig. 19 is a sectional view taken along line B1-B1 of Fig. 11 showing the same internal meshing planetary gear unit.

Fig. 20 is an explanatory view showing the arrangement of rolling bearings in the above internal meshing planetary gear unit.

Fig. 21 is a schematic sectional view showing a lubricant circulation path in the above internal meshing planetary gear unit.

22 is an explanatory diagram schematically showing the flow of lubricant when focusing on the third region in the internal meshing planetary gear unit as above.

Fig. 23 is a schematic diagram showing how lubricant is circulated in a circulation path by a pump function in the above internal meshing planetary gear unit.

Fig. 24 is an enlarged schematic cross-sectional view of the vicinity of the third region of the same internal meshing planetary gear device.

Fig. 25 is a schematic explanatory view showing the replacement procedure of the inner pin in the above internal meshing planetary gear unit.

FIG. 26 is a schematic explanatory view showing the replacement procedure of the rolling elements in the above internal meshing planetary gear unit.

Fig. 27 is a schematic cross-sectional view showing a joint device for a robot using the same internal meshing planetary gear device.

Fig. 28 is a schematic cross-sectional view for comparing the above internal meshing planetary gear device with a modified internal meshing planetary gear device.

Fig. 29 is a schematic cross-sectional view of an internal meshing planetary gear unit according to a second embodiment.

Detailed ways

(basic structure)

(1) Summary

Hereinafter, the outline of the internal meshing planetary gear unit 1 according to the basic configuration will be described with reference to FIGS. 1 to 3 . The drawings referred to in the embodiments of the present disclosure are all schematic diagrams, and the ratios of the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual size ratios. For example, the tooth shape, size, and number of teeth of the internal teeth 21 and the external teeth 31 in FIGS. 1-3 are only schematically shown for illustration, and are not limited to the illustrated shapes.

The internal meshing planetary gear unit 1 (hereinafter also simply referred to as “gear unit 1 ”) related to this basic structure is a gear unit including an inner gear 2 , a planetary gear 3 and a plurality of inner pins 4 . In this gear unit 1 , a planetary gear 3 is arranged inside an annular internal gear 2 , and an eccentric body bearing 5 is arranged inside the planetary gear 3 . The eccentric body bearing 5 has an eccentric inner ring 51 and an eccentric outer ring 52. The eccentric inner ring 51 rotates (eccentric motion) around a rotation axis Ax1 (see FIG. 3 ) deviated from the center C1 (see FIG. 3 ) of the eccentric inner ring 51, This causes the planetary gear 3 to oscillate. The eccentric inner ring 51 rotates around the rotation axis Ax1 (eccentric motion) when the eccentric shaft 7 inserted into the eccentric inner ring 51 rotates, for example. In addition, the internal meshing planetary gear unit 1 further includes a bearing member 6 having an outer ring 62 and an inner ring 61 . The inner ring 61 is arranged inside the outer ring 62 and supported so as to be relatively rotatable with respect to the outer ring 62 .

The internal gear 2 has internal teeth 21 and is fixed to the outer ring 62 . Especially in this basic structure, the internal gear 2 has an annular gear body 22 and a plurality of pins 23 . The plurality of pins 23 are rotatably held on the inner peripheral surface 221 of the gear main body 22 to constitute the internal teeth 21 . The planet gears 3 have external teeth 31 which partially mesh with the internal teeth 21 . That is, the inner side of the planetary gear 3 is inscribed with the internal gear 2 , and a part of the external teeth 31 meshes with a part of the internal teeth 21 . In this state, when the eccentric shaft 7 rotates, the planetary gear 3 swings, and the meshing position of the internal teeth 21 and the external teeth 31 moves in the circumferential direction of the internal gear 2, between the two gears (the internal gear 2 and the planetary gear 3). A relative rotation corresponding to the difference in the number of teeth between the planetary gear 3 and the internal gear 2 is generated. Here, when the internal gear 2 is fixed, the planetary gear 3 rotates (autorotates) along with the relative rotation of both gears. As a result, a rotational output decelerated by a high reduction ratio in accordance with the difference in the number of teeth of both gears is obtained from the planetary gear 3 .

Such a gear device 1 is used to extract the rotation corresponding to the autorotation component of the planetary gear 3 as, for example, the rotation of an output shaft integrated with the inner ring 61 of the bearing member 6 . Thus, the gear unit 1 functions as a gear unit having a high reduction ratio, with the eccentric shaft 7 as the input side and the output shaft as the output side. Therefore, in the gear device 1 according to this basic structure, the planetary gear 3 and the inner ring 61 are connected by a plurality of inner pins 4 in order to transmit the rotation corresponding to the rotation component of the planetary gear 3 to the inner ring 61 of the bearing member 6 . The plurality of inner pins 4 are inserted into the plurality of inner pin holes 32 formed in the planetary gear 3 , and rotate relative to the inner gear 2 while revolving in the inner pin holes 32 . That is, the inner pin hole 32 has a larger diameter than the inner pin 4 , and the inner pin 4 can move so as to revolve in the inner pin hole 32 while being inserted into the inner pin hole 32 . Also, the swing component of the planetary gear 3 , that is, the revolution component of the planetary gear 3 is absorbed by the loose fit between the inner pin hole 32 of the planetary gear 3 and the inner pin 4 . In other words, as the plurality of inner pins 4 move so as to revolve in the plurality of inner pin holes 32 , the swinging component of the planetary gear 3 is absorbed. Therefore, the rotation (autorotation component) of the planetary gear 3 other than the swinging component (revolution component) of the planetary gear 3 is transmitted to the inner ring 61 of the bearing member 6 through the plurality of inner pins 4 .

However, in such a gear device 1, the inner pin 4 transmits the rotation of the planetary gear 3 to a plurality of inner pins 4 while revolving in the inner pin hole 32 of the planetary gear 3. Therefore, as a first related art, it is known to use a The inner pin 4 is an inner roller capable of rotating around the inner pin 4. That is to say, in the first related art, the inner pin 4 is held in a state of being pressed into the inner ring 61 (or the carrier integrated with the inner ring 61 ), and when the inner pin 4 revolves in the inner pin hole 32 , the inner pin 4 is opposed to the inner pin 4 . Sliding on the inner peripheral surface 321 of the inner pin hole 32 . Therefore, as the first related art, in order to reduce the loss caused by the frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 , inner rollers are used. However, in a structure including inner rollers as in the first related art, the inner pin hole 32 needs to have a diameter capable of revolving the inner pin 4 with inner rollers, and it is difficult to miniaturize the inner pin hole 32 . If the miniaturization of the inner pin hole 32 is difficult, the miniaturization (in particular, diameter reduction) of the planetary gear 3 will be hindered, and further the miniaturization of the gear device 1 as a whole will be hindered. The gear device 1 according to this basic configuration can provide an internal meshing planetary gear device 1 that can be easily downsized by the following configuration.

That is to say, as shown in FIGS. 1-3 , the gear device 1 involved in this basic structure includes a bearing component 6 , an internal gear 2 , a planetary gear 3 and a plurality of internal pins 4 . The bearing member 6 has an outer ring 62 and an inner ring 61 disposed inside the outer ring 62 . The inner ring 61 is supported so as to be relatively rotatable with respect to the outer ring 62 . The internal gear 2 has internal teeth 21 and is fixed to the outer ring 62 . The planet gears 3 have external teeth 31 which partially mesh with the internal teeth 21 . The plurality of inner pins 4 relatively rotate with respect to the inner gear 2 while revolving in the inner pin holes 32 while being respectively inserted into the plurality of inner pin holes 32 formed in the planetary gear 3 . Here, each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state. In addition, at least a part of each of the plurality of inner pins 4 is arranged at the same position as that of the bearing member 6 in the axial direction of the bearing member 6 .

According to this aspect, each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state. Therefore, when the inner pins 4 revolve in the inner fitting holes 32 , the inner pins 4 themselves can rotate. Therefore, loss due to frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 can be reduced without using an inner roller mounted on the inner pin 4 and rotatable about the inner pin 4 . Therefore, in the gear unit 1 according to this basic structure, the inner roller is unnecessary, and there is an advantage that miniaturization is easy. Furthermore, since at least a part of each of the plurality of inner pins 4 is arranged at the same position as the bearing member 6 in the axial direction of the bearing member 6 , the size of the gear device 1 in the axial direction of the bearing member 6 can be kept small. That is, compared with the structure in which the bearing member 6 and the inner pin 4 are arranged (opposite) in the axial direction of the bearing member 6, in the gear device 1 according to this basic structure, the axial direction of the gear device 1 can be reduced. size, thereby contributing to further miniaturization (thinning) of the gear unit 1 .

In addition, if the size of the planetary gear 3 is the same as that of the above-mentioned first related art, then compared with the above-mentioned first related art, for example, it is also possible to increase the number (number) of inner pins 4 to make the transmission of rotation smooth, and to thicken the inner pins 4 to make Increase strength.

In addition, in such a gear device 1, since the inner pins 4 need to revolve in the inner pin holes 32 of the planetary gear 3, as the second related art, sometimes a plurality of inner pins 4 are formed only by the inner ring 61 (or integrated with the inner ring 61). planet carrier) to keep. According to the second related art, it is difficult to improve the accuracy of the centering of the plurality of inner pins 4 , and poor centering may cause problems such as vibration and reduction in transmission efficiency. That is, each of the plurality of inner pins 4 rotates relative to the inner gear 2 while revolving in the inner pin hole 32 , thereby transmitting the rotation component of the planetary gear 3 to the inner ring 61 of the bearing member 6 . At this time, if the accuracy of the centering of the plurality of inner pins 4 is insufficient, the rotation shafts of the plurality of inner pins 4 deviate or incline relative to the rotation axis of the inner ring 61, resulting in poor centering, resulting in vibration and transmission. Adverse situations such as reduced efficiency. The gear device 1 according to this basic configuration can provide an internal meshing planetary gear device 1 that is less likely to cause problems caused by poor centering of the plurality of inner pins 4 by the following configuration.

That is to say, as shown in FIGS. 1-3 , the gear device 1 involved in this basic structure includes an internal gear 2 , a planetary gear 3 , a plurality of internal pins 4 and a support body 8 . The internal gear 2 has an annular gear body 22 and a plurality of pins 23 . The plurality of pins 23 are rotatably held on the inner peripheral surface 221 of the gear body 22 to constitute the internal teeth 21 . The planet gears 3 have external teeth 31 which partially mesh with the internal teeth 21 . The plurality of inner pins 4 relatively rotate with respect to the gear main body 22 while revolving in the inner pin holes 32 while being respectively inserted into the plurality of inner pin holes 32 formed in the planetary gear 3 . The support body 8 supports a plurality of inner pins 4 for the annular ring. Here, the position of the support body 8 is restricted by bringing the outer peripheral surface 81 into contact with the plurality of pins 23 .

According to this aspect, since the plurality of inner pins 4 are supported by the annular support body 8 , the plurality of inner pins 4 are bundled by the support body 8 , and relative displacement and inclination of the plurality of inner pins 4 are suppressed. Furthermore, the outer peripheral surface 81 of the support body 8 is in contact with the plurality of pins 23 , thereby restricting the position of the support body 8 . In short, the support body 8 is centered by the plurality of pins 23 , and as a result, the plurality of inner pins 4 supported by the support body 8 are also centered by the plurality of pins 23 . Therefore, the gear unit 1 according to this basic structure has the advantage of being easy to improve the accuracy of the centering of the plurality of inner pins 4 and less likely to cause troubles caused by poor centering of the plurality of inner pins 4 .

In addition, as shown in FIG. 1 , the gear unit 1 according to this basic configuration constitutes an actuator 100 together with a drive source 101 . In other words, the actuator 100 related to this basic structure includes the gear unit 1 and the drive source 101 . The driving source 101 generates driving force for swinging the planetary gear 3 . Specifically, the drive source 101 oscillates the planetary gear 3 by rotating the eccentric shaft 7 about the rotation axis Ax1 .

(2) Definition

The term "ring" in the embodiments of the present disclosure refers to a shape such as a wrap that forms a surrounded space (region) inside at least when viewed from a plan view, and is not limited to a circular shape that is a perfect circle when viewed from a plan view. (annular shape), for example, an elliptical shape, a polygonal shape, etc. may be used. Furthermore, for example, even a shape having a bottom such as a cup shape is included in the "annular shape" as long as its peripheral wall is annular.

The term “fitting with play” in the embodiments of the present disclosure refers to fitting in a state with a play (gap), and the inner pin hole 32 is a hole for the inner pin 4 to be fitted with a play. That is, the inner pin 4 is inserted into the inner pin hole 32 with a margin of space (gap) secured between the inner peripheral surface 321 of the inner pin hole 32 . In other words, the diameter of at least the portion of the inner pin 4 inserted into the inner pin hole 32 is smaller (thinner) than the diameter of the inner pin hole 32 . Therefore, the inner pin 4 is movable in the inner pin hole 32 in a state inserted into the inner pin hole 32 , that is, relatively movable with respect to the center of the inner pin hole 32 . Therefore, the inner pin 4 can revolve inside the inner pin hole 32 . However, it is not necessary to ensure a gap as a cavity between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 , and a fluid such as liquid may be filled in the gap, for example.

The "revolution" mentioned in the embodiments of the present disclosure means that an object rotates around a rotation axis other than the central axis passing through the center (center of gravity) of the object. When an object revolves, the center of the object rotates along the rotation axis. The orbital raceway in the center moves. Therefore, for example, when the object rotates around an eccentric axis parallel to a central axis passing through the center (center of gravity) of a certain object, the object revolves around the eccentric axis as a rotation axis. As an example, the inner pin 4 rotates around a rotation axis passing through the center of the inner pin hole 32 , and revolves inside the inner pin hole 32 .

In addition, in the embodiments of the present disclosure, one side of the rotation axis Ax1 (the left side in FIG. 3 ) is sometimes called “input side”, and the other side of the rotation axis Ax1 (the right side in FIG. 3 ) is sometimes called “input side”. "Output side". In the example of FIG. 3, rotation is applied to the rotating body (eccentric inner ring 51) from the "input side" of the rotation axis Ax1, and the rotation of the plurality of inner pins 4 (inner ring 61) is taken out from the "output side" of the rotation axis Ax1. However, "input side" and "output side" are labels added for explanation only, and are not intended to limit the positional relationship between the input and output viewed from the gear device 1 .

The "axis of rotation" referred to in the embodiments of the present disclosure refers to an imaginary axis (straight line) that becomes the center of the rotational motion of the rotating body. That is, the rotation axis Ax1 is a virtual axis without a substance. The eccentric inner ring 51 rotates about the rotation axis Ax1.

The "internal teeth" and "external teeth" mentioned in the embodiments of the present disclosure are not individual "teeth", but a collection (group) of a plurality of "teeth". That is, the internal teeth 21 of the internal gear 2 are constituted by a set of a plurality of teeth arranged on the inner peripheral surface 221 of the internal gear 2 (gear body 22 ). Similarly, the external teeth 31 of the planetary gear 3 are constituted by a set of a plurality of teeth arranged on the outer peripheral surface of the planetary gear 3 .

(3) Structure

Hereinafter, the detailed structure of the internal meshing planetary gear device 1 according to this basic structure will be described with reference to FIGS. 1 to 8B .

FIG. 1 is a perspective view showing a schematic configuration of an actuator 100 including a gear device 1 . FIG. 1 schematically shows a driving source 101 . FIG. 2 is a schematic exploded perspective view of the gear unit 1 viewed from the output side of the rotation axis Ax1. FIG. 3 is a schematic sectional view of the gear device 1 . Fig. 4 is a sectional view taken along line A1-A1 of Fig. 3 . However, in FIG. 4 , hatching is omitted for components other than the eccentric shaft 7 even if they are cross sections. In addition, in FIG. 4 , illustration of the inner peripheral surface 221 of the gear main body 22 is omitted. 5A and 5B are a perspective view and a front view showing the planetary gear 3 as a single body. 6A and 6B are perspective views and front views showing the bearing member 6 as a single body. 7A and 7B are perspective views and front views showing the eccentric shaft 7 as a single body. 8A and 8B are perspective views and front views showing the support body 8 as a single body.

(3.1) Overall structure

As shown in Figures 1-3, the gear device 1 involved in this basic structure includes an internal gear 2, a planetary gear 3, a plurality of internal pins 4, an eccentric body bearing 5, a bearing component 6, an eccentric shaft 7 and a support body 8. In addition, in this basic structure, the gear device 1 further includes a first bearing 91 , a second bearing 92 and a housing 10 . In this basic structure, the internal gear 2, the planetary gear 3, the plurality of inner pins 4, the eccentric body bearing 5, the bearing member 6, the eccentric shaft 7, and the support body 8, which are the constituent elements of the gear unit 1, are made of stainless steel, cast iron, etc. , Carbon steel, chromium molybdenum steel, phosphor bronze or aluminum bronze and other metals for mechanical structure. The metal mentioned here includes metals subjected to surface treatment such as nitriding treatment.

In addition, in this basic configuration, an inscribed planetary gear device using a trochoidal tooth profile is exemplified as an example of the gear device 1 . That is to say, the gear device 1 according to this basic structure includes an inscribed planetary gear 3 having a trochoid-like curved tooth profile.

In addition, in this basic configuration, as an example, the gear unit 1 is used in a state where the gear main body 22 of the internal gear 2 is fixed to a fixed member such as the housing 10 together with the outer ring 62 of the bearing member 6 . Accordingly, the planetary gear 3 relatively rotates with respect to the fixed member (casing 10 and the like) along with the relative rotation of the internal gear 2 and the planetary gear 3 .

Furthermore, in this basic structure, when the gear unit 1 is used for the actuator 100, by applying a rotational force as an input to the eccentric shaft 7, the output shaft integrated with the inner ring 61 of the bearing member 6 is extracted as output rotational force. That is, the gear device 1 operates with the rotation of the eccentric shaft 7 as an input rotation and the rotation of an output shaft integrated with the inner ring 61 as an output rotation. Accordingly, in the gear device 1 , the output rotation decelerated by a high reduction ratio relative to the input rotation can be obtained.

The drive source 101 is a power generation source such as a motor (electric motor). Power generated by the drive source 101 is transmitted to the eccentric shaft 7 of the gear unit 1 . Specifically, the drive source 101 is connected to the eccentric shaft 7 via an input shaft, and the power generated by the drive source 101 is transmitted to the eccentric shaft 7 via the input shaft. Thus, the drive source 101 can rotate the eccentric shaft 7 .

In addition, in the gear transmission 1 according to this basic configuration, as shown in FIG. 3 , the input side rotation axis Ax1 and the output side rotation axis Ax1 are located on the same straight line. In other words, the rotation axis Ax1 on the input side is coaxial with the rotation axis Ax1 on the output side. Here, the rotation axis Ax1 on the input side is the rotation center of the eccentric shaft 7 to which the input rotation is applied, and the rotation axis Ax1 on the output side is the rotation center of the inner ring 61 (and the output shaft) that generates the output rotation. That is, in the gear unit 1 , the output rotation reduced by a high reduction ratio relative to the input rotation is obtained coaxially.

As shown in FIG. 4 , the internal gear 2 is an annular component having internal teeth 21 . In this basic structure, the internal gear 2 has an annular shape in which at least the inner peripheral surface is a perfect circle in plan view. Internal teeth 21 are formed on the inner peripheral surface of the ring-shaped internal gear 2 along the circumferential direction of the internal gear 2 . All the plurality of teeth constituting the internal teeth 21 have the same shape, and are arranged at equal intervals over the entire area of the inner peripheral surface of the internal gear 2 in the circumferential direction. That is to say, the pitch circle of the internal teeth 21 is regarded as a perfect circle in plan view. The center of the pitch circle of the internal teeth 21 lies on the axis of rotation Ax1. In addition, the internal gear 2 has a predetermined thickness in the direction of the rotation axis Ax1. The tooth lines of the internal teeth 21 are all parallel to the rotation axis Ax1. The size of the tooth line direction of the internal teeth 21 is slightly smaller than the thickness direction of the internal gear 2 .

Here, as described above, the internal gear 2 has a ring-shaped (annular) gear body 22 and a plurality of pins 23 . The plurality of pins 23 are rotatably held on the inner peripheral surface 221 of the gear main body 22 to constitute the internal teeth 21 . In other words, each of the plurality of pins 23 functions as a plurality of teeth constituting the internal teeth 21 . Specifically, as shown in FIG. 2 , a plurality of grooves are formed in the entire area of the inner peripheral surface 221 of the gear main body 22 in the circumferential direction. All of the plurality of grooves have the same shape and are arranged at equal intervals. Each of the plurality of grooves is parallel to the rotation axis Ax1 and formed over the entire length of the gear main body 22 in the thickness direction. A plurality of pins 23 are combined with the gear main body 22 so as to fit into a plurality of grooves. Each of the plurality of pins 23 is held in the groove in a rotatable state. In addition, the gear main body 22 (together with the outer ring 62 ) is fixed to the housing 10 . Therefore, a plurality of fixing holes 222 for fixing are formed in the gear main body 22 .

As shown in FIG. 4 , the planetary gear 3 is an annular component having external teeth 31 . In this basic structure, the planetary gear 3 has an annular shape in which at least the outer peripheral surface is a perfect circle when viewed in plan. On the outer peripheral surface of the annular planetary gear 3 , external teeth 31 are formed along the circumferential direction of the planetary gear 3 . All the plurality of teeth constituting the external teeth 31 have the same shape, and are provided at equal intervals over the entire area of the outer peripheral surface of the planetary gear 3 in the circumferential direction. That is to say, the pitch circle of the external teeth 31 is regarded as a perfect circle in plan view. The center C1 of the pitch circle of the external teeth 31 is located at a position deviated from the rotation axis Ax1 by a distance ΔL (see FIG. 4 ). The planetary gear 3 has a predetermined thickness in the direction of the rotation axis Ax1. The external teeth 31 are formed over the entire length of the planetary gear 3 in the thickness direction. The tooth lines of the external teeth 31 are all parallel to the rotation axis Ax1. In the planetary gear 3 , unlike the internal gear 2 , the external teeth 31 are integrally formed with the main body of the planetary gear 3 by one metal member.

Here, the eccentric body bearing 5 and the eccentric shaft 7 are combined with the planetary gear 3 . That is, the planetary gear 3 is formed with an opening 33 opening in a circular shape. The opening 33 is a hole penetrating through the planetary gear 3 in the thickness direction. The center of the opening 33 coincides with the center of the planetary gear 3 in plan view, and the inner peripheral surface of the opening 33 (the inner peripheral surface of the planetary gear 3 ) is concentric with the pitch circle of the external teeth 31 . The eccentric body bearing 5 is accommodated in the opening 33 of the planetary gear 3 . Furthermore, by inserting the eccentric shaft 7 into (the eccentric inner ring 51 of) the eccentric body bearing 5 , the eccentric body bearing 5 and the eccentric shaft 7 are combined with the planetary gear 3 . In a state where the eccentric body bearing 5 and the eccentric shaft 7 are combined with the planetary gear 3 , when the eccentric shaft 7 rotates, the planetary gear 3 oscillates around the rotation axis Ax1 .

The planetary gear 3 configured in this way is disposed inside the internal gear 2 . The planetary gear 3 is formed one revolution smaller than the internal gear 2 in a plan view, and the planetary gear 3 can swing inside the internal gear 2 in a state combined with the internal gear 2 . Here, external teeth 31 are formed on the outer peripheral surface of the planetary gear 3 , and internal teeth 21 are formed on the inner peripheral surface of the internal gear 2 . Therefore, in a state where the planetary gear 3 is arranged inside the internal gear 2 , the external teeth 31 and the internal teeth 21 face each other.

Also, the pitch circle of the external teeth 31 is smaller by one turn than the pitch circle of the internal teeth 21 . And, in a state where the planetary gear 3 is inscribed on the internal gear 2, the center C1 of the pitch circle of the external teeth 31 is located at a distance ΔL (see FIG. 4 ) away from the center of the pitch circle of the internal teeth 21 (rotation axis Ax1). Location. Therefore, the external teeth 31 and the internal teeth 21 at least partially face each other with gaps therebetween, and do not mesh with each other entirely in the circumferential direction. However, since the planetary gear 3 oscillates (revolves) around the rotation axis Ax1 inside the internal gear 2 , the external teeth 31 partially mesh with the internal teeth 21 . That is, as the planetary gear 3 swings around the rotation axis Ax1 , as shown in FIG. 4 , some of the plurality of teeth constituting the external teeth 31 mesh with some of the plurality of teeth constituting the internal teeth 21 . As a result, in the gear device 1 , a part of the external teeth 31 can be meshed with a part of the internal teeth 21 .

Here, the number of internal teeth 21 of the internal gear 2 is greater than the number of external teeth 31 of the planetary gear 3 by N (N is a positive integer). In this basic configuration, N is "1" as an example, and the number of teeth of the planetary gear 3 (of the external teeth 31 ) is "1" larger than the number of teeth of the internal gear 2 (of the internal teeth 21 ). Such a difference in the number of teeth between the planetary gear 3 and the internal gear 2 defines the reduction ratio of the output rotation to the input rotation in the gear device 1 .

In addition, in this basic structure, as an example, the thickness of the planetary gear 3 is smaller than the thickness of the gear main body 22 of the internal gear 2 . Furthermore, the size of the external teeth 31 in the tooth line direction (direction parallel to the rotation axis Ax1 ) is smaller than the size of the internal teeth 21 in the tooth line direction (direction parallel to the rotation axis Ax1 ). In other words, in a direction parallel to the rotation axis Ax1 , the external teeth 31 are contained within the range of the tooth line of the internal teeth 21 .

In this basic structure, as described above, the rotation corresponding to the autorotation component of the planetary gear 3 is taken out as the rotation of the output shaft integrated with the inner ring 61 of the bearing member 6 (output rotation). Therefore, the planetary gear 3 is coupled to the inner ring 61 via the plurality of inner pins 4 . As shown in FIGS. 5A and 5B , a plurality of inner pin holes 32 for inserting a plurality of inner pins 4 are formed on the planetary gear 3 . The number of inner pin holes 32 is the same as the number of inner pins 4 , and in this basic structure, as an example, 18 inner pin holes 32 and 18 inner pins 4 are provided. Each of the plurality of inner pin holes 32 has a circular opening and is a hole penetrating through the planetary gear 3 in the thickness direction. A plurality of (here, 18) inner pin holes 32 are arranged at equal intervals in the circumferential direction on an imaginary circle concentric with the opening 33 .

The plurality of inner pins 4 are components that connect the planetary gear 3 and the inner ring 61 of the bearing member 6 . The plurality of inner pins 4 are each formed in a cylindrical shape. The diameter and length of the plurality of inner pins 4 are common among the plurality of inner pins 4 . The diameter of the inner pin 4 is one circle smaller than the diameter of the inner pin hole 32 . Accordingly, the inner pin 4 is inserted into the inner pin hole 32 with a margin of space (clearance) secured between the inner peripheral surface 321 of the inner pin hole 32 (see FIG. 4 ).

The bearing member 6 has an outer ring 62 and an inner ring 61 , and is a component for taking out the output of the gear unit 1 as the rotation of the inner ring 61 relative to the outer ring 62 . The bearing component 6 has a plurality of rolling elements 63 (see FIG. 3 ) in addition to the outer ring 62 and the inner ring 61 .

As shown in FIGS. 6A and 6B , both the outer ring 62 and the inner ring 61 are annular parts. Both the outer ring 62 and the inner ring 61 have an annular shape that is a perfect circle when viewed from above. The inner ring 61 is one turn smaller than the outer ring 62 and is disposed inside the outer ring 62 . Here, since the inner diameter of the outer ring 62 is larger than the outer diameter of the inner ring 61 , a gap is formed between the inner peripheral surface of the outer ring 62 and the outer peripheral surface of the inner ring 61 .

The inner ring 61 has a plurality of holding holes 611 into which the plurality of inner pins 4 are respectively inserted. The holding holes 611 are provided in the same number as the inner pins 4 , and in this basic structure, as an example, eighteen holding holes 611 are provided. As shown in FIGS. 6A and 6B , each of the plurality of holding holes 611 has a circular opening and is a hole penetrating through the inner ring 61 in the thickness direction. A plurality of (here, 18) holding holes 611 are arranged at equal intervals in the circumferential direction on an imaginary circle concentric with the outer circumference of the inner ring 61 . The diameter of the holding hole 611 is larger than the diameter of the inner pin 4 and smaller than the diameter of the inner pin hole 32 .

Furthermore, the inner ring 61 is integrated with the output shaft, and the rotation of the inner ring 61 is taken out as the rotation of the output shaft. Therefore, the inner ring 61 is formed with a plurality of output side mounting holes 612 (see FIG. 2 ) for mounting the output shaft. In this basic structure, the plurality of output-side mounting holes 612 are arranged on the inner side of the plurality of holding holes 611 and on an imaginary circle concentric with the outer circumference of the inner ring 61 .

The outer ring 62 is fixed to a fixed member such as the housing 10 together with the gear main body 22 of the internal gear 2 . Therefore, a plurality of through holes 621 for fixing are formed in the outer ring 62 . Specifically, as shown in FIG. 3 , with the outer ring 62 interposed between the housing 10 and the gear main body 22 , screws (bolts) 60 for fixing are passed through the through holes 621 and the fixing holes 222 of the gear main body 22 . fixed to the housing 10.

A plurality of rolling elements 63 are arranged in a gap between the outer ring 62 and the inner ring 61 . The plurality of rolling elements 63 are arranged in line in the circumferential direction of the outer ring 62 . All of the plurality of rolling elements 63 are metal parts of the same shape, and are arranged at equal intervals over the entire area of the outer ring 62 in the circumferential direction.

In this basic structure, the bearing member 6 is a cross roller bearing as an example. That is, the bearing member 6 has cylindrical rollers as the rolling elements 63 . Furthermore, the axis of the cylindrical rolling element 63 has an inclination of 45 degrees with respect to a plane perpendicular to the rotation axis Ax1 , and is perpendicular to the outer circumference of the inner ring 61 . In addition, a pair of rolling elements 63 that are adjacent to each other in the circumferential direction of the inner ring 61 are arranged so that their axial directions are perpendicular to each other. In the bearing member 6 composed of such a crossed roller bearing, it is easy to receive radial load, thrust direction (direction along the rotation axis Ax1) load, and bending force (bending moment load) for the rotation axis Ax1. either one. Furthermore, these three kinds of loads can be withstood by one bearing member 6, and necessary rigidity can be ensured.

As shown in FIGS. 7A and 7B , the eccentric shaft 7 is a cylindrical part. The eccentric shaft 7 has a shaft center portion 71 and an eccentric portion 72 . The axial center portion 71 has a cylindrical shape in which at least the outer peripheral surface is a perfect circle when viewed in plan. The center (central axis) of the shaft center portion 71 coincides with the rotation axis Ax1. The eccentric portion 72 has a disc shape in which at least the outer peripheral surface is a perfect circle in plan view. The center (central axis) of the eccentric portion 72 coincides with the center C1 shifted from the rotation axis Ax1. Here, the distance ΔL (see FIG. 7B ) between the rotation axis Ax1 and the center C1 is the amount of eccentricity of the eccentric portion 72 with respect to the axial center portion 71 . The eccentric portion 72 is formed in a central portion in the longitudinal direction (axial direction) of the axial portion 71 in a flange shape protruding from the outer peripheral surface of the axial portion 71 over the entire circumference. According to the above configuration, the eccentric shaft 7 rotates (rotates) around the rotation axis Ax1 by the shaft center portion 71 , and the eccentric portion 72 performs eccentric motion.

In this basic structure, the shaft center portion 71 and the eccentric portion 72 are integrally formed of one metal member, whereby the seamless eccentric shaft 7 is realized. The eccentric shaft 7 having such a shape is combined with the planetary gear 3 together with the eccentric body bearing 5 . Therefore, when the eccentric shaft 7 rotates in a state where the eccentric body bearing 5 and the eccentric shaft 7 are combined with the planetary gear 3 , the planetary gear 3 oscillates around the rotation axis Ax1 .

Furthermore, the eccentric shaft 7 has a through hole 73 penetrating through the shaft center portion 71 in the axial direction (longitudinal direction). The through hole 73 opens in a circular shape on both axial end surfaces of the axial center portion 71 . The center (central axis) of the through hole 73 coincides with the rotation axis Ax1. For example, cables such as power supply lines and signal lines can pass through the through holes 73 .

In addition, in this basic structure, a rotational force is applied as an input to the eccentric shaft 7 from the drive source 101 . Therefore, a plurality of input-side mounting holes 74 for mounting the input shaft connected to the drive source 101 are formed in the eccentric shaft 7 (see FIGS. 7A and 7B ). In this basic structure, a plurality of input-side mounting holes 74 are arranged around the through-hole 73 on one axial end surface of the shaft center portion 71 , and are arranged on an imaginary circle concentric with the through-hole 73 .

The eccentric body bearing 5 has an eccentric outer ring 52 and an eccentric inner ring 51, and is used to absorb the rotation component of the rotation of the eccentric shaft 7, and only the rotation of the eccentric shaft 7 from which the rotation component of the eccentric shaft 7 has been removed, that is, the rotation of the eccentric shaft 7 The swing component (revolution component) is transmitted to the components of the planetary gear 3 . The eccentric body bearing 5 has a plurality of rolling elements 53 (see FIG. 3 ) in addition to the eccentric outer ring 52 and the eccentric inner ring 51 .

Both the eccentric outer ring 52 and the eccentric inner ring 51 are annular parts. Both the eccentric outer ring 52 and the eccentric inner ring 51 have an annular shape that is a perfect circle when viewed from above. The eccentric inner ring 51 is one turn smaller than the eccentric outer ring 52 and is arranged inside the eccentric outer ring 52 . Here, since the inner diameter of the eccentric outer ring 52 is larger than the outer diameter of the eccentric inner ring 51 , a gap is formed between the inner peripheral surface of the eccentric outer ring 52 and the outer peripheral surface of the eccentric inner ring 51 .

The plurality of rolling elements 53 are arranged in the gap between the eccentric outer ring 52 and the eccentric inner ring 51 . The plurality of rolling elements 53 are arranged in line in the circumferential direction of the eccentric outer ring 52 . All of the plurality of rolling elements 53 are metal parts of the same shape, and are provided at equal intervals throughout the entire area of the eccentric outer ring 52 in the circumferential direction. In this basic structure, as an example, the eccentric body bearing 5 is constituted by a deep groove ball bearing using balls as the rolling elements 53 .

Here, the inner diameter of the eccentric inner ring 51 coincides with the outer diameter of the eccentric portion 72 of the eccentric shaft 7 . The eccentric body bearing 5 is combined with the eccentric shaft 7 in a state where the eccentric portion 72 of the eccentric shaft 7 is inserted into the eccentric inner ring 51 . In addition, the outer diameter of the eccentric outer ring 52 coincides with the inner diameter (diameter) of the opening 33 of the planetary gear 3 . The eccentric body bearing 5 is combined with the planetary gear 3 in a state where the eccentric outer ring 52 is fitted into the opening 33 of the planetary gear 3 . In other words, the eccentric body bearing 5 mounted on the eccentric portion 72 of the eccentric shaft 7 is housed in the opening 33 of the planetary gear 3 .

In addition, in this basic structure, as an example, the dimension of the eccentric inner ring 51 of the eccentric body bearing 5 in the width direction (direction parallel to the rotation axis Ax1 ) is substantially the same as the thickness of the eccentric portion 72 of the eccentric shaft 7 . The dimension in the width direction (direction parallel to the rotation axis Ax1 ) of the eccentric outer ring 52 is slightly smaller than the dimension in the width direction of the eccentric inner ring 51 . Furthermore, the dimension in the width direction of the eccentric outer ring 52 is larger than the thickness of the planetary gear 3 . Therefore, the planetary gear 3 is accommodated within the range of the eccentric body bearing 5 in a direction parallel to the rotation axis Ax1. On the other hand, the dimension in the width direction of the eccentric outer ring 52 is smaller than the dimension in the tooth line direction (direction parallel to the rotation axis Ax1 ) of the internal teeth 21 . Therefore, the eccentric body bearing 5 is accommodated within the range of the internal gear 2 in a direction parallel to the rotation axis Ax1.

In the state where the eccentric body bearing 5 and the eccentric shaft 7 are combined with the planetary gear 3, when the eccentric shaft 7 rotates, in the eccentric body bearing 5, the eccentric inner ring 51 revolves around the rotation axis deviated from the center C1 of the eccentric inner ring 51. Ax1 rotates (eccentric movement). At this time, the rotation component of the eccentric shaft 7 is absorbed by the eccentric body bearing 5 . Therefore, only the rotation of the eccentric shaft 7 other than the rotation component of the eccentric shaft 7 , that is, the swing component (revolution component) of the eccentric shaft 7 is transmitted to the planetary gear 3 through the eccentric body bearing 5 . Therefore, in a state where the eccentric body bearing 5 and the eccentric shaft 7 are combined with the planetary gear 3 , when the eccentric shaft 7 rotates, the planetary gear 3 oscillates around the rotation axis Ax1 .

As shown in FIGS. 8A and 8B , the support body 8 is formed in a ring shape and supports a plurality of inner pins 4 . The support body 8 has a plurality of support holes 82 into which the plurality of inner pins 4 are respectively inserted. The support holes 82 are provided in the same number as the inner pins 4 , and in this basic structure, as an example, 18 support holes 82 are provided. As shown in FIGS. 8A and 8B , each of the plurality of support holes 82 has a circular opening and is a hole penetrating through the support body 8 in the thickness direction. A plurality of (here, 18) support holes 82 are arranged at equal intervals in the circumferential direction on an imaginary circle concentric with the outer peripheral surface 81 of the support body 8 . The diameter of the support hole 82 is equal to or larger than the diameter of the inner pin 4 and smaller than the diameter of the inner pin hole 32 . In this basic structure, as an example, the diameter of the support hole 82 is equal to the diameter of the holding hole 611 formed in the inner ring 61 .

As shown in FIG. 3 , the support body 8 is arranged to face the planetary gear 3 from the rotation axis Ax1 side (input side). And, by inserting the plurality of inner pins 4 into the plurality of support holes 82 , the support body 8 functions to bundle the plurality of inner pins 4 . Furthermore, the position of the support body 8 is restricted by bringing the outer peripheral surface 81 into contact with the plurality of pins 23 . As a result, the support body 8 is centered by the plurality of pins 23 , and as a result, the plurality of inner pins 4 supported by the support body 8 are also centered by the plurality of pins 23 . The support body 8 will be described in detail in "(3.3) Support body".

The first bearing 91 and the second bearing 92 are mounted on the shaft center portion 71 of the eccentric shaft 7 , respectively. Specifically, as shown in FIG. 3 , the first bearing 91 and the second bearing 92 are attached to both sides of the eccentric portion 72 of the shaft center portion 71 so as to sandwich the eccentric portion 72 in a direction parallel to the rotation axis Ax1 . Seen from the eccentric portion 72, the first bearing 91 is disposed on the input side of the rotation axis Ax1. Viewed from the eccentric portion 72, the second bearing 92 is arranged on the output side of the rotation axis Ax1. The first bearing 91 holds the eccentric shaft 7 rotatably relative to the housing 10 . The second bearing 92 holds the eccentric shaft 7 rotatably relative to the inner ring 61 of the bearing member 6 . Thereby, the axial center portion 71 of the eccentric shaft 7 is held rotatably at two locations on both sides of the eccentric portion 72 in a direction parallel to the rotation axis Ax1.

The housing 10 has a cylindrical shape and has a flange portion 11 on the output side of the rotation axis Ax1. A plurality of installation holes 111 for fixing the housing 10 itself are formed in the flange portion 11 . In addition, a bearing hole 12 is formed on the output side end surface of the rotating shaft Ax1 of the housing 10 . The bearing hole 12 opens in a circular shape. By fitting the first bearing 91 into the bearing hole 12 , the first bearing 91 is attached to the casing 10 .

In addition, a plurality of screw holes 13 are formed on the output side end surface of the rotating shaft Ax1 of the housing 10 and around the bearing hole 12 . The plurality of threaded holes 13 are used to fix the gear main body 22 of the internal gear 2 and the outer ring 62 of the bearing member 6 to the housing 10 . Specifically, the fixing screw 60 is fastened to the threaded hole 13 through the through hole 621 of the outer ring 62 and the fixing hole 222 of the gear body 22 , whereby the gear body 22 and the outer ring 62 are fixed to the housing 10 .

In addition, as shown in FIG. 3 , the gear unit 1 according to this basic structure further includes a plurality of oil seals 14 , 15 , 16 and the like. The oil seal 14 is attached to the end portion of the eccentric shaft 7 on the input side of the rotation axis Ax1, and closes the gap between the housing 10 and the eccentric shaft 7 (shaft portion 71). The oil seal 15 is attached to the end portion of the eccentric shaft 7 on the output side of the rotary shaft Ax1, and closes the gap between the inner ring 61 and the eccentric shaft 7 (shaft portion 71). The oil seal 16 is attached to the output side end surface of the rotating shaft Ax1 of the bearing member 6 and closes the gap between the inner ring 61 and the outer ring 62 . The space sealed by these plurality of oil seals 14, 15, 16 constitutes a lubricant holding space 17 (see FIG. 9). The lubricant holding space 17 includes a space between the inner ring 61 and the outer ring 62 of the bearing component 6 . Furthermore, a plurality of pins 23 , the planetary gear 3 , the eccentric body bearing 5 , the support body 8 , the first bearing 91 and the second bearing 92 , and the like are accommodated in the lubricant holding space 17 .

In addition, lubricant is injected into the lubricant holding space 17 . The lubricant is liquid and can flow in the lubricant holding space 17 . Therefore, when the gear unit 1 is used, for example, lubricant enters the meshing portion between the internal teeth 21 constituted by the plurality of pins 23 and the external teeth 31 of the planetary gear 3 . The "liquid" mentioned in the embodiments of the present disclosure includes liquid or gel-like substances. The term "gel" as used herein refers to a state having intermediate properties between liquid and solid, and includes a state of a colloid composed of two phases, a liquid phase and a solid phase. For example, the dispersion medium is a liquid phase, the dispersoid is an emulsion (emulsion) of the liquid phase, and the dispersoid is a solid phase suspension (suspension), which is called a gel (gel) or a state of a sol (sol). gelatinous". In addition, a state where the dispersion medium is a solid phase and the dispersoid is a liquid phase is also included in the "gel state". In this basic structure, the lubricant is liquid lubricating oil (oil) as an example.

In the gear unit 1 configured as described above, when an input rotational force is applied to the eccentric shaft 7, the eccentric shaft 7 rotates about the rotation axis Ax1, whereby the planetary gear 3 oscillates (revolves) around the rotation axis Ax1. At this time, the planetary gear 3 swings in a state where the inner side of the internal gear 2 is inscribed with the internal gear 2 and a part of the external teeth 31 meshes with a part of the internal teeth 21. Therefore, the meshing position of the internal teeth 21 and the external teeth 31 is inside Gear 2 moves in the circumferential direction. Accordingly, relative rotation corresponding to the difference in the number of teeth between the planetary gear 3 and the internal gear 2 is generated between the two gears (the internal gear 2 and the planetary gear 3 ). And, the rotation (autorotation component) of the planetary gear 3 other than the swinging component (revolution component) of the planetary gear 3 is transmitted to the inner ring 61 of the bearing member 6 through the plurality of inner pins 4 . As a result, a rotational output decelerated by a high reduction ratio in accordance with the difference in the number of teeth of both gears is obtained from the output shaft integrated with the inner ring 61 .

However, in the gear device 1 of the present embodiment, as described above, the difference in the number of teeth between the internal gear 2 and the planetary gear 3 defines the reduction ratio of the output rotation to the input rotation in the gear device 1 . That is, when the number of teeth of the internal gear 2 is "V1" and the number of teeth of the planetary gear 3 is "V2", the speed reduction ratio R1 is expressed by the following formula 1.

R1=V2/(V1-V2)...(Formula 1)

In short, the smaller the tooth number difference (V1-V2) between the internal gear 2 and the planetary gear 3, the larger the reduction ratio R1. As an example, the number of teeth V1 of the internal gear 2 is "52", the number of teeth V2 of the planetary gear 3 is "51", and the difference between the number of teeth (V1-V2) is "1". Therefore, according to the above formula 1, the reduction ratio R1 is " 51". In this case, when viewed from the input side of the rotation axis Ax1, when the eccentric shaft 7 rotates clockwise around the rotation axis Ax1 once (360 degrees), the inner ring 61 rotates counterclockwise around the rotation axis Ax1. "The amount (ie about 7.06 degrees).

With the gear unit 1 according to this basic structure, such a high reduction ratio R1 can be realized by combining the gears of the first stage (internal gear 2 and planetary gear 3).

In addition, the gear device 1 only needs to include at least an internal gear 2, a planetary gear 3, a plurality of internal pins 4, a bearing member 6, and a support body 8, and may further include, for example, a spline housing and the like as constituent elements.

However, as in the gear unit 1 according to this basic structure, when the input rotation on the high-speed rotation side is accompanied by eccentric motion, if the weight balance of the high-speed rotating body cannot be achieved, vibrations may be caused. Weight balance is sometimes achieved using a counterweight or the like. That is, since the rotating body constituted by at least one of the eccentric inner ring 51 and the member (eccentric shaft 7) that rotates together with the eccentric inner ring 51 performs eccentric motion at high speed, it is preferable to obtain the rotation of the rotating body with respect to the rotation axis Ax1. weight balance. In this basic structure, as shown in FIGS. 3 and 4 , by providing a gap 75 in a part of the eccentric portion 72 of the eccentric shaft 7 , weight balance of the rotating body with respect to the rotating shaft Ax1 is achieved.

In short, in this basic structure, the weight of the rotating body with respect to the rotating shaft Ax1 is balanced by reducing the weight of a part of the rotating body (here, the eccentric shaft 7 ) without adding a balance weight or the like. . That is, the gear unit 1 according to this basic structure includes the eccentric body bearing 5 accommodated in the opening 33 formed in the planetary gear 3 and causing the planetary gear 3 to oscillate. The eccentric body bearing 5 has an eccentric outer ring 52 and an eccentric inner ring 51 arranged inside the eccentric outer ring 52 . Viewed from the rotation axis Ax1 of the eccentric inner ring 51 , a rotating body composed of at least one of the eccentric inner ring 51 and members rotating together with the eccentric inner ring 51 has a gap 75 in a part of the eccentric outer ring 52 on the center C1 side. In this basic structure, the eccentric shaft 7 is "a member that rotates together with the eccentric inner ring 51" and corresponds to a "rotary body". Therefore, the gap 75 formed in the eccentric portion 72 of the eccentric shaft 7 corresponds to the gap 75 of the rotating body. As shown in FIG. 3 and FIG. 4 , since the gap 75 is located on the center C1 side when viewed from the rotation axis Ax1 , the gap 75 functions to make the weight balance of the eccentric shaft 7 approximately equal in the circumferential direction from the rotation axis Ax1 .

More specifically, the gap 75 includes a concave portion formed on the inner peripheral surface of the through hole 73 penetrating the rotating body along the rotation axis Ax1 of the eccentric inner ring 51 . That is, in this basic structure, since the rotating body is the eccentric shaft 7 , the recess formed on the inner peripheral surface of the through hole 73 penetrating the eccentric shaft 7 along the rotating axis Ax1 functions as the void 75 . Thus, by using the recessed part formed in the inner peripheral surface of the through-hole 73 as the space|gap 75, the weight balance of a rotating body can be acquired without accompanying a change in appearance.

(3.2) The rotation structure of domestic sales

Next, the autorotation structure of the inner pin 4 of the gear unit 1 according to this basic structure will be described in more detail with reference to FIG. 9 . FIG. 9 is an enlarged view of a region Z1 in FIG. 3 .

First, as a premise, as described above, the plurality of inner pins 4 are components that connect the planetary gear 3 and the inner ring 61 of the bearing member 6 . Specifically, one end in the longitudinal direction of the inner pin 4 (the end on the input side of the rotation axis Ax1 in this basic structure) is inserted into the inner pin hole 32 of the planetary gear 3, and the other end in the longitudinal direction of the inner pin 4 (in this basic structure) is inserted into the inner pin hole 32 of the planetary gear 3 . In the basic configuration, the end portion on the output side of the rotation shaft Ax1 is inserted into the holding hole 611 of the inner ring 61 .

Here, the diameter of the inner pin 4 is one circle smaller than the diameter of the inner pin hole 32, so a gap is ensured between the inner pin 4 and the inner peripheral surface 321 of the inner pin hole 32, and the inner pin 4 can move in the inner pin hole 32, that is, can move relative to the inner pin hole 32. The centers of the holes 32 move relative to each other. On the other hand, although the diameter of the holding hole 611 is larger than the diameter of the inner pin 4 , it is smaller than the diameter of the inner pin hole 32 . In this basic structure, the diameter of the holding hole 611 is approximately the same as that of the inner pin 4 and slightly larger than that of the inner pin 4 . Therefore, movement of the inner pin 4 within the holding hole 611 is restricted, that is, relative movement with respect to the center of the holding hole 611 is prohibited. Therefore, the inner pin 4 is held in the planetary gear 3 in a state capable of revolving in the inner pin hole 32 , and is held in a state incapable of revolving in the holding hole 611 with respect to the inner ring 61 . Thus, the swing component of the planetary gear 3, that is, the revolution component of the planet gear 3 is absorbed by the loose fit between the inner pin hole 32 and the inner pin 4, and the swing component (revolution component) of the planetary gear 3 is absorbed by the plurality of inner pins 4. The other rotation (rotation component) is transmitted to the inner ring 61 .

However, in this basic structure, the diameter of the inner pin 4 is slightly larger than that of the holding hole 611, so that when the inner pin 4 is inserted into the holding hole 611, it is prohibited from revolving in the holding hole 611, but it can rotate in the holding hole 611. . That is, since the inner pin 4 is not pressed into the holding hole 611 even when it is inserted into the holding hole 611 , it can rotate in the holding hole 611 . In this way, in the gear unit 1 according to this basic configuration, the plurality of inner pins 4 are each rotatably held by the inner ring 61 , so that when the inner pins 4 revolve in the inner fitting holes 32 , the inner pins 4 themselves are rotatable.

In short, in this basic structure, the inner pin 4 is held in a state capable of revolving and rotating in the inner pin hole 32 with respect to the planetary gear 3 , and is held in a state capable of rotating only in the holding hole 611 with respect to the inner ring 61 . Keep. That is, the plurality of inner pins 4 are rotatable (revolvable) around the rotation axis Ax1 in a state where their respective rotations are not restricted (rotatable state), and are capable of revolving in the plurality of inner pin holes 32 . Therefore, when the rotation (rotation component) of the planetary gear 3 is transmitted to the inner ring 61 by the plurality of inner pins 4 , the inner pins 4 can rotate in the holding holes 611 while revolving and rotating in the inner pin holes 32 . Therefore, when the inner pin 4 revolves in the inner pin hole 32 , the inner pin 4 is in a state capable of rotating on its own, and thus rolls with respect to the inner peripheral surface 321 of the inner pin hole 32 . In other words, the inner pin 4 revolves in the inner pin hole 32 while rolling on the inner peripheral surface 321 of the inner pin hole 32 , so loss due to frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 is less likely to occur.

In this way, in the structure related to this basic structure, since loss due to frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 hardly occurs, the inner roller can be omitted. Therefore, in this basic structure, a structure is adopted in which a plurality of inner pins 4 are respectively in direct contact with the inner peripheral surface 321 of the inner pin hole 32 . That is, in this basic structure, the inner pin 4 without the inner roller is inserted into the inner pin hole 32 , and the inner pin 4 directly contacts the inner peripheral surface 321 of the inner pin hole 32 . Thereby, the inner roller can be omitted, and the diameter of the inner pin hole 32 can be suppressed to be small. Therefore, the planetary gear 3 can be downsized (in particular, the diameter can be downsized), and the gear device 1 as a whole can also be easily downsized. If the size of the planetary gear 3 is fixed, compared to the first related art, for example, the number (number) of inner pins 4 may be increased to smooth transmission of rotation, and the inner pins 4 may be thickened to increase strength. Furthermore, the number of components can be reduced by the amount corresponding to the inner roller, and the cost reduction of the gear device 1 can also be achieved.

In addition, in the gear device 1 according to this basic configuration, at least a part of each of the plurality of inner pins 4 is arranged at the same position as the bearing member 6 in the axial direction of the bearing member 6 . That is, as shown in FIG. 9 , at least a part of the inner pin 4 is arranged at the same position as the bearing member 6 in the direction parallel to the rotation axis Ax1 . In other words, at least a part of the inner pin 4 is located between both end surfaces of the bearing member 6 in a direction parallel to the rotation axis Ax1. In other words, at least a part of each of the plurality of inner pins 4 is arranged inside the outer ring 62 of the bearing member 6 . In this basic structure, the end portion of the inner pin 4 on the output side of the rotation axis Ax1 is located at the same position as the bearing member 6 in the direction parallel to the rotation axis Ax1 . In short, the end portion of the inner pin 4 on the output side of the rotation axis Ax1 is inserted into the holding hole 611 formed in the inner ring 61 of the bearing member 6, so that at least the end portion is arranged on the bearing member 6 in the axial direction of the bearing member 6. 6 same position.

Thus, by arranging at least a part of each of the plurality of inner pins 4 at the same position as the bearing member 6 in the axial direction of the bearing member 6, the dimension of the gear device 1 in the direction parallel to the rotation axis Ax1 can be suppressed relatively. Small. That is to say, compared with the structure in which the bearing member 6 and the inner pin 4 are arranged (opposite) in the axial direction of the bearing member 6, in the gear device 1 according to this basic structure, the difference between the gear device 1 and the gear device 1 can be reduced. The dimension in the direction parallel to the rotation axis Ax1 can contribute to further miniaturization (thinning) of the gear device 1 .

Here, the opening surface of the holding hole 611 on the output side of the rotation shaft Ax1 is closed by, for example, an output shaft integrated with the inner ring 61 or the like. Accordingly, the movement of the inner pin 4 to the output side (right side in FIG. 9 ) of the rotation axis Ax1 is regulated by the output shaft integrated with the inner ring 61 or the like.

In addition, in this basic structure, in order to make the inner pin 4 rotate smoothly with respect to the inner ring 61, the following structure is employ|adopted. In other words, the inner pin 4 is smoothly rotated by allowing lubricant (lubricating oil) to intervene between the inner peripheral surface of the holding hole 611 formed in the inner ring 61 and the inner pin 4 . In particular, in this basic structure, there is a lubricant holding space 17 for injecting lubricant between the inner ring 61 and the outer ring 62, so the smooth rotation of the inner pin 4 is realized by using the lubricant in the lubricant holding space 17. change.

In this basic structure, as shown in FIG. 9 , the inner ring 61 has a plurality of holding holes 611 and a plurality of connecting passages 64 into which the plurality of inner pins 4 are respectively inserted. The plurality of connecting passages 64 connect the lubricant holding space 17 between the inner ring 61 and the outer ring 62 with the plurality of holding holes 611 . Specifically, the inner ring 61 is formed with a connecting path 64 extending in the radial direction from a portion of the inner peripheral surface of the holding hole 611 , that is, a portion corresponding to the rolling elements 63 . The connecting passage 64 is a hole that penetrates between the bottom surface of the recess (groove) that accommodates the rolling elements 63 and the inner peripheral surface of the holding hole 611 on the surface of the inner ring 61 that faces the outer ring 62 . In other words, the opening surface of the connection passage 64 on the side of the lubricant holding space 17 is disposed at a position facing (opposing) the rolling elements 63 of the bearing member 6 . The lubricant holding space 17 and the holding hole 611 are spatially connected via such a connecting path 64 .

According to the above configuration, since the lubricant holding space 17 and the holding hole 611 are connected by the connecting path 64 , the lubricant in the lubricant holding space 17 is supplied to the holding hole 611 through the connecting path 64 . That is, when the bearing member 6 operates and the rolling element 63 rotates, the rolling element 63 functions as a pump and can send the lubricant in the lubricant holding space 17 into the holding hole 611 through the connection passage 64 . In particular, the opening surface of the connection path 64 on the side of the lubricant holding space 17 is positioned to face (opposite) the rolling elements 63 of the bearing member 6, whereby the rolling elements 63 are effective as a pump when the rolling elements 63 rotate. play a role. As a result, the lubricant intervenes between the inner peripheral surface of the holding hole 611 and the inner pin 4 , and smooth rotation of the inner pin 4 relative to the inner ring 61 can be achieved.

(3.3) Support body

Next, the structure of the support body 8 of the gear unit 1 according to this basic structure will be described in more detail with reference to FIG. 10 . Fig. 10 is a sectional view taken along line B1-B1 in Fig. 3 . However, in FIG. 10 , hatching is omitted for parts other than the support body 8 even if it is a cross section. In addition, in FIG. 10, only the internal gear 2 and the support body 8 are illustrated, and illustration of other parts (inner pin 4 etc.) is abbreviate|omitted. In addition, in FIG. 10 , illustration of the inner peripheral surface 221 of the gear main body 22 is omitted.

First, as a premise, as described above, the support body 8 is a component that supports the plurality of inner pins 4 . That is, the support body 8 disperses the load applied to the plurality of inner pins 4 when transmitting the rotation (rotation component) of the planetary gear 3 to the inner ring 61 by bundling the plurality of inner pins 4 . Specifically, it has a plurality of support holes 82 into which the plurality of inner pins 4 are respectively inserted. In this basic structure, as an example, the diameter of the support hole 82 is equal to the diameter of the holding hole 611 formed in the inner ring 61 . Therefore, the support body 8 supports the plurality of inner pins 4 in a state where the plurality of inner pins 4 can rotate. That is, the plurality of inner pins 4 are held by the inner ring 61 of the bearing member 6 and the support body 8 in a state capable of rotating with respect to the inner ring 61 of the bearing member 6 and the support body 8 , respectively.

In this way, the support body 8 performs positioning of the plurality of inner pins 4 relative to the support body 8 in both the circumferential direction and the radial direction. That is, by inserting the inner pin 4 into the support hole 82 of the support body 8 , the movement of the inner pin 4 with respect to all directions within a plane orthogonal to the rotation axis Ax1 is restricted. Therefore, the inner pin 4 is positioned not only in the circumferential direction but also in the radial direction (radial direction) on the support body 8 .

Here, the support body 8 has an annular shape in which at least the outer peripheral surface 81 is a perfect circle in plan view. Further, the position of the support body 8 is restricted by bringing the outer peripheral surface 81 into contact with the plurality of pins 23 of the internal gear 2 . Since the plurality of pins 23 constitute the internal teeth 21 of the internal gear 2 , in other words, the support body 8 is position-regulated by bringing the outer peripheral surface 81 into contact with the internal teeth 21 . Here, the diameter of the outer peripheral surface 81 of the support body 8 is the same as the diameter of an imaginary circle (addendum circle) passing through the tips of the internal teeth 21 of the internal gear 2 . Therefore, all of the plurality of pins 23 are in contact with the outer peripheral surface 81 of the support body 8 . Therefore, in a state where the support body 8 is position-regulated by the plurality of pins 23 , the center of the support body 8 is position-regulated so as to coincide with the center of the internal gear 2 (the rotation axis Ax1 ). Thereby, the centering of the support body 8 is performed, and as a result, the plurality of inner pins 4 supported by the support body 8 are also centered by the plurality of pins 23 .

In addition, the plurality of inner pins 4 transmits the rotation (autorotation component) of the planetary gear 3 to the inner ring 61 by rotating (revolving) around the rotation axis Ax1 . Therefore, the support body 8 supporting the plurality of inner pins 4 rotates around the rotation axis Ax1 together with the plurality of inner pins 4 and the inner ring 61 . At this time, since the support body 8 is centered by the plurality of pins 23, the support body 8 rotates smoothly with the center of the support body 8 maintained on the rotation axis Ax1. And since the support body 8 rotates in the state which contacted the some pin 23 with the outer peripheral surface 81, several pins 23 each rotate (rotate) along with the rotation of the support body 8. Therefore, the support body 8 constitutes a needle bearing (needle roller bearing) together with the internal gear 2 and rotates smoothly.

That is, the outer peripheral surface 81 of the support body 8 relatively rotates with the plurality of inner pins 4 relative to the gear main body 22 in a state of being in contact with the plurality of pins 23 . Therefore, if the gear main body 22 of the internal gear 2 is regarded as an "outer ring" and the outer ring support body 8 is regarded as an "inner ring", the plurality of pins 23 between the two are regarded as "rolling elements (rollers"). ) function. In this way, the support body 8 constitutes a needle bearing together with the internal gear 2 (gear body 22 and a plurality of pins 23), and can rotate smoothly.

In addition, since the support body 8 sandwiches a plurality of pins 23 between it and the gear main body 22, the support body 8 also functions as a "stopper" that suppresses the movement of the pins 23 in a direction away from the inner peripheral surface 221 of the gear main body 22. effect. That is, the plurality of pins 23 are sandwiched between the outer peripheral surface 81 of the support body 8 and the inner peripheral surface 221 of the gear main body 22 , thereby suppressing the plurality of pins 23 from floating from the inner peripheral surface 221 of the gear main body 22 . In short, in this basic structure, the plurality of pins 23 are restricted from moving in the direction away from the gear main body 22 by contacting the outer peripheral surface 81 of the support body 8 , respectively.

However, in this basic structure, as shown in FIG. 9 , the support body 8 is located on the opposite side to the inner ring 61 of the bearing member 6 across the planetary gear 3 . That is, the support body 8 , the planetary gear 3 , and the inner ring 61 are arranged side by side in a direction parallel to the rotation axis Ax1 . In this basic structure, as an example, the support body 8 is located on the input side of the rotation axis Ax1 viewed from the planetary gear 3 , and the inner ring 61 is located on the output side of the rotation axis Ax1 viewed from the planetary gear 3 . The support body 8 supports both ends of the inner pin 4 in the longitudinal direction (direction parallel to the rotation axis Ax1 ) together with the inner ring 61 , and the longitudinal center of the inner pin 4 is inserted into the inner pin hole 32 of the planetary gear 3 . In short, the gear unit 1 according to this basic structure includes a bearing member 6 having an outer ring 62 and an inner ring 61 arranged inside the outer ring 62 , and the inner ring 61 is supported so as to be able to face the outer ring 62 . rotate. Furthermore, the gear main body 22 is fixed to the outer ring 62 . In this case, the planet gears 3 are located between the carrier body 8 and the inner ring 61 in the axial direction of the carrier body 8 .

According to this structure, since the support body 8 and the inner ring 61 support both ends of the inner pin 4 in the longitudinal direction, the inner pin 4 is less likely to incline. In particular, it is also easy to receive a bending force (bending moment load) applied to the plurality of inner pins 4 with respect to the rotation axis Ax1. In addition, in this basic structure, the support body 8 is sandwiched between the planetary gear 3 and the case 10 in a direction parallel to the rotation axis Ax1. Thus, the housing 10 restricts the movement of the support body 8 to the input side (the left side in FIG. 9 ) of the rotation axis Ax1. The inner pin 4 that penetrates the support hole 82 of the support body 8 and protrudes from the support body 8 to the input side of the rotation axis Ax1 is also restricted by the housing 10 from moving to the input side of the rotation axis Ax1 (left side in FIG. 9 ).

In this basic structure, the support body 8 and the inner ring 61 are also in contact with both ends of the plurality of pins 23 . That is, as shown in FIG. 9 , the support body 8 is in contact with one end (the end on the input side of the rotation axis Ax1 ) of the pin 23 in the longitudinal direction (the direction parallel to the rotation axis Ax1 ). The inner ring 61 is in contact with the other end portion (end portion on the output side of the rotation axis Ax1 ) of the pin 23 in the longitudinal direction (direction parallel to the rotation axis Ax1 ). According to this structure, since the support body 8 and the inner ring 61 are centered by the both ends of the pin 23 in the longitudinal direction, the inner pin 4 is less likely to incline. In particular, it is also easy to receive a bending force (bending moment load) applied to the plurality of inner pins 4 with respect to the rotation axis Ax1.

In addition, the plurality of pins 23 have a length equal to or greater than the thickness of the support body 8 . In other words, the support body 8 is accommodated within the range of the tooth line of the internal tooth 21 in a direction parallel to the rotation axis Ax1. Thereby, the outer peripheral surface 81 of the support body 8 is in contact with the plurality of pins 23 over the entire length in the tooth line direction (direction parallel to the rotation axis Ax1 ) of the internal teeth 21 . Therefore, it is less likely to cause a problem such as "unilateral wear" in which the outer peripheral surface 81 of the support body 8 is partially worn.

In addition, in this basic structure, the surface roughness of the outer peripheral surface 81 of the support body 8 is smaller than that of one surface adjacent to the outer peripheral surface 81 of the support body 8 . That is, the surface roughness of the outer peripheral surface 81 is smaller than that of both end surfaces in the axial direction (thickness direction) of the support body 8 . The "surface roughness" mentioned in the embodiments of the present disclosure refers to the degree of surface roughness of an object, and the smaller the value, the smaller (fewer) the unevenness of the surface and the smoother it is. In this basic structure, as an example, the surface roughness is arithmetic mean roughness (Ra). For example, the surface roughness of the outer peripheral surface 81 is smaller than that of the surfaces other than the outer peripheral surface 81 of the support body 8 by processing such as grinding. In this structure, the rotation of the support body 8 becomes smoother.

In addition, in this basic structure, the hardness of the outer peripheral surface 81 of the support body 8 is lower than that of the peripheral surfaces of the plurality of pins 23 and higher than that of the inner peripheral surface 221 of the gear main body 22 . The "hardness" mentioned in the embodiments of the present disclosure refers to the hardness of an object, and the hardness of a metal is represented by, for example, the size of a pit formed by pressing a steel ball with a certain pressure. Specifically, examples of metal hardness include Rockwell hardness (HRC), Brinell hardness (HB), Vickers hardness (HV), Shore hardness (Hs), and the like. Methods for increasing (increasing) the hardness of metal parts include, for example, alloying or heat treatment. In this basic structure, as an example, the hardness of the outer peripheral surface 81 of the support body 8 is increased by carburizing and quenching. In this structure, even by the rotation of the support body 8, abrasion powder etc. are hard to generate|occur|produce, and it becomes easy to maintain the smooth rotation of the support body 8 for a long time.

(4) Application example

Next, an application example of the gear device 1 and the actuator 100 according to the basic configuration will be described.

The gear device 1 and the actuator 100 related to this basic structure are applied to, for example, a horizontal articulated robot, that is, a so-called Selective Compliance Assembly Robot Arm (SCARA: Selective Compliance Assembly Robot Arm) type robot.

In addition, the application examples of the gear device 1 and the actuator 100 according to this basic structure are not limited to the above-mentioned horizontal articulated robot, and may be industrial robots other than the horizontal articulated robot or robots other than the industrial robot. Examples of industrial robots other than the horizontal articulated robot include a vertical articulated robot, a parallel link robot, and the like. Examples of non-industrial robots include household robots, care robots, and medical robots.

(first embodiment)

The internal meshing planetary gear device 1A of this embodiment (hereinafter referred to simply as "gear device 1A") is mainly related to the structure around the inner pin 4 and the structure around the input shaft (eccentric shaft 7) as shown in Figs. The basic structure of the gear unit 1 is different. Hereinafter, the same reference numerals are attached to the same configuration as the basic configuration, and explanations thereof are appropriately omitted.

FIG. 11 is a schematic cross-sectional view of the gear device 1A. FIG. 12 is a schematic cross-sectional view of the gear unit 1A in a state where a bush 70 described later is removed. FIG. 13 is a side view of the gear unit 1A viewed from the input side of the rotation axis Ax1 (the left side in FIG. 11 ). 11 corresponds to a sectional view taken along line A1 - A1 of FIG. 13 , and FIG. 12 corresponds to a sectional view taken along line B1 - A1 of FIG. 13 . FIG. 14 is a side view of the gear unit 1A viewed from the output side of the rotation axis Ax1 (the right side in FIG. 11 ). In FIG. 13 and FIG. 14 , the enlarged diagrams of the respective Z1-Z1 line sections are shown in drawn frames. FIG. 15 is a schematic cross-sectional view of a state where

cover bodies

163 and 164 and

oil seals

14 and 15 described later are removed in the same cross-sectional view as FIG. Fig. 16 is a side view of the gear unit 1A with the

covers

163, 164 and

oil seals

14, 15 removed, viewed from the input side of the rotary shaft Ax1 (left side in Fig. 15). Fig. 17 is a side view of the gear unit 1A in a state where the

covers

163, 164 and the oil seals 14, 15 are removed, viewed from the output side of the rotary shaft Ax1 (the right side in Fig. 15 ).

The first main difference between the gear unit 1A of this embodiment and the basic structure is that the structure supporting the plurality of inner pins 4 (support structure 40 ) holds both ends of the inner pins 4 by rolling

bearings

41 and 42 . That is, the gear device 1A includes a plurality of sets of rolling

bearings

41 , 42 respectively holding a plurality of inner pins 4 at both sides in a direction parallel to the rotation axis Ax1 with respect to the planetary gear 3 . The plurality of inner pins 4 are held by the respective sets of rolling

bearings

41 , 42 in a rotatable state. Here, the plurality of inner pins 4 are inserted into the plurality of inner pin holes 32 formed in the planetary gear 3 , and rotate relative to the inner gear 2 around the rotation axis Ax1 while revolving in the inner pin holes 32 .

In addition, the second main difference between the gear device 1A of this embodiment and the basic structure is that a structure for improving the lubrication state of the inner pin 4 is adopted. Specifically, the gear device 1A includes a circulation path 170 (see FIG. 21 ) including the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 and the rolling elements 402 in the rolling bearings 41, 42 (see FIG. 21 ). 20) raceway 404 (see Figure 20). The gear unit 1A circulates the lubricant through the circulation path 170 . That is, in this embodiment, the lubrication state of the inner pin 4 is improved by providing the circulation path 170 to circulate the lubricant.

The third main difference between the gear unit 1A of the present embodiment and the basic structure is that the plurality of inner pins 4 can be detached at least in a state where the bearing member 6A, the inner gear 2 and the planetary gear 3 are combined. That is, the gear unit 1A includes the internal pin path Sp1 (see FIG. 15 ). The inner pin path Sp1 is located on at least one side in the direction parallel to the rotation axis Ax1 with respect to the plurality of inner pins 4, and the plurality of inner pins 4 can be disassembled in a state where the bearing member 6A, the inner gear 2, and the planetary gear 3 are combined. Down. Further, the plurality of inner pins 4 are arranged inside the inner ring 61 (of the bearing member 6A) when viewed in a direction parallel to the rotation axis Ax1.

Also, the rolling elements 402 (see FIG. 20 ) of the rolling

bearings

41 and 42 are detachable at least in the state in which the bearing member 6A, the internal gear 2 and the planetary gear 3 are combined, similarly to the inner pin 4 . Specifically, the rolling elements 402 of the rolling

bearings

41 and 42 are detachable toward the opposite side of the planetary gear 3 with respect to the outer ring 62 (of the bearing member 6A) in a direction parallel to the rotation axis Ax1 .

In addition, the fourth main difference of the gear device 1A of this embodiment from the basic structure is that the bush 70 is provided with a fixing structure 701 for fixing a mating member to the eccentric shaft 7 serving as an input shaft. That is, the gear unit 1A includes an input shaft (eccentric shaft 7 ) that eccentrically oscillates the planetary gear 3 and a bush 70 . The bush 70 has a fixing structure 701 for fixing a mating part, and is combined with the input shaft (eccentric shaft 7 ) to rotate together with the input shaft (eccentric shaft 7 ).

In short, the main difference between the gear device 1A of this embodiment and the basic structure is that the structure around the inner pin 4 is newly adopted, especially the design related to the support structure 40 (rolling bearings 41, 42) for the inner pin 4, and is used to improve the inner pin. The design of the lubricated state of 4 and the design that the inner pin 4 can be removed. Furthermore, the main difference between the gear unit 1A and the basic structure is that the structure around the input shaft (eccentric shaft 7 ), especially the design related to the bush 70 , is newly adopted. Here, the rolling

bearings

41 and 42 are fixed to the inner ring 61 of the bearing member 6A, and the inner pin 4 is held by the inner ring 61 of the bearing member 6A via the rolling

bearings

41 and 42 . Therefore, in the gear device 1A of the present embodiment, the point that each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state is also the same as the basic configuration.

In the gear device 1A of this embodiment, in addition to the above-mentioned main differences (the structure around the inner pin 4 and the structure around the input shaft), there are many differences from the basic structure as described below.

As another first point of difference, the bearing member 6A of the gear device 1A of the present embodiment includes a first bearing member 601A and a second bearing member 602A. The first bearing member 601A and the second bearing member 602A are respectively composed of angular contact ball bearings, and have an inner ring 61 , an outer ring 62 , and a plurality of rolling elements 63 . Both the inner ring 61 of the first bearing member 601A and the inner ring 61 of the second bearing member 602A have an annular shape, and their outer peripheral surfaces are viewed as a perfect circle centered on the rotation axis Ax1 in plan view. Specifically, as shown in FIG. 11 , the first bearing member 601A is arranged on the input side of the rotation axis Ax1 (left side in FIG. 11 ) viewed from the planetary gear 3 , and on the output side of the rotation axis Ax1 viewed from the planetary gear 3 . (Right side in FIG. 11 ) The second bearing member 602A is arranged. The bearing member 6A is configured to receive a radial load, a load in the thrust direction (direction along the rotation axis Ax1), and a bending force (bending force) with respect to the rotation axis Ax1 through the first bearing member 601A and the second bearing member 602A. any of the moment loads).

Here, the first bearing member 601A and the second bearing member 602A are arranged opposite to each other in the direction parallel to the rotation axis Ax1 with respect to both sides of the planetary gear 3 in the direction parallel to the rotation axis Ax1 . That is, the bearing member 6A is a "combined angular contact ball bearing" in which a plurality (here, two) of angular contact ball bearings is combined. Here, as an example, the first bearing member 601A and the second bearing member 602A are "back combined type" that receive a load in the direction in which the respective inner rings 61 approach each other, that is, the thrust direction (direction along the rotation axis Ax1). Furthermore, in the gear device 1A, the first bearing member 601A and the second bearing member 602A are combined in a state where an appropriate preload is applied to the inner ring 61 by fastening the respective inner rings 61 in directions to approach each other. The term "preload" in the embodiments of the present disclosure refers to a state in which internal stress is always applied by pre-applying pressure, which is a so-called preload. That is, in the gear device 1A of the present embodiment, in each of the first bearing member 601A and the second bearing member 602A, the rolling elements 63 are pressed against the outer ring 62 from outside in a direction parallel to the rotation axis Ax1 .

As another second difference, as shown in FIG. 11 , a gear unit 1A of the present embodiment includes a carrier flange 18 and an output flange 19 . The carrier flange 18 and the output flange 19 are arranged on both sides of the planetary gear 3 in a direction parallel to the rotation axis Ax1, and are connected to each other through the carrier hole 34 (see FIG. 12 ) of the planetary gear 3 . Specifically, as shown in FIG. 11 , the planetary carrier flange 18 is disposed on the input side of the rotation axis Ax1 (left side in FIG. 11 ) when viewed from the planetary gear 3 , and on the output side of the rotation axis Ax1 when viewed from the planetary gear 3 . (right side of FIG. 11 ) configure the output flange 19. The inner ring 61 of the bearing part 6A (of each of the first bearing part 601A and the second bearing part 602A) is fixed relative to the planet carrier flange 18 and the output flange 19 . In this embodiment, as an example, the inner ring 61 of the first bearing member 601A is seamlessly integrated with the carrier flange 18 . Likewise, the inner ring 61 of the second bearing member 602A is seamlessly integrated with the output flange 19 .

The output flange 19 has a plurality of (six as an example) carrier pins 191 protruding from one surface of the output flange 19 toward the input side of the rotation axis Ax1 (see FIG. 12 ). The plurality of carrier pins 191 respectively pass through a plurality of (six as an example) carrier holes 34 formed in the planetary gear 3 , and their top ends are fixed to the carrier flange 18 by carrier bolts 181 (see FIG. 12 ). . Here, the diameter of the carrier pin 191 is slightly smaller than the diameter of the carrier hole 34, and a gap is ensured between the carrier pin 191 and the inner peripheral surface of the carrier hole 34, so that the carrier pin 191 can fit inside the carrier hole 34. It can move relative to the center of the planet carrier hole 34 . And, the gap between the planetary carrier pin 191 and the inner peripheral surface of the planetary carrier hole 34 is larger than the gap between the inner pin 4 and the inner peripheral surface 321 of the inner pin hole 32. When the inner pin 4 revolves in the inner pin hole 32, the planetary carrier The pin 191 is not in contact with the inner peripheral surface of the carrier hole 34 . In addition, a plurality of flange bolt holes 192 for fixing the output flange 19 itself are formed on the surface of the output flange 19 on the opposite side to the carrier pin 191 (see FIG. 17 ).

Here, both ends of the inner pin 4 are held not directly by the inner ring 61 of the bearing member 6A but (via rolling bearings 41 , 42 ) by the carrier flange 18 and the output flange 19 integrated with the inner ring 61 . That is, the plurality of inner pins 4 are indirectly held by the inner ring 61 of the bearing member 6A by being held by the carrier flange 18 and the output flange 19 .

Thus, the gear unit 1A is used to extract the rotation corresponding to the rotation component of the planetary gear 3 as the rotation of the carrier flange 18 and the output flange 19 integrated with the inner ring 61 of the bearing member 6A. That is, in the basic structure, the relative rotation between the planetary gear 3 and the internal gear 2 is taken out as the rotation component of the planetary gear 3 from the inner ring 61 connected to the planetary gear 3 by the plurality of inner pins 4 . On the other hand, in the present embodiment, the relative rotation between the planetary gear 3 and the internal gear 2 is extracted from the carrier flange 18 and the output flange 19 integrated with the inner ring 61 . In the present embodiment, as an example, the gear unit 1A is used in a state where the outer ring 62 of the bearing member 6A is fixed to a case that is a fixed member. That is, the planetary gear 3 is connected to the planetary carrier flange 18 and the output flange 19 as rotating parts through a plurality of internal pins 4, and the gear main body 22 is fixed to the fixed part, so the relative rotation between the planetary gear 3 and the internal gear 2 Take it out from the rotating parts (planetary carrier flange 18 and output flange 19). In other words, in this embodiment, when the plurality of inner pins 4 rotate relative to the gear body 22 , the rotational force of the carrier flange 18 and the output flange 19 is taken out as an output.

As another third point of difference, in the present embodiment, the housing 10 is seamlessly integrated with the gear main body 22 of the internal gear 2 . That is, in the basic structure, the gear main body 22 of the internal gear 2 is used in a state of being fixed to the housing 10 together with the outer ring 62 of the bearing member 6 . On the other hand, in this embodiment, the gear main body 22 and the housing 10 which are fixed members are continuously provided seamlessly in the direction parallel to the rotation axis Ax1.

More specifically, the housing 10 has a cylindrical shape and constitutes the outer shape of the gear unit 1A. In this embodiment, the central axis of the cylindrical housing 10 is configured to coincide with the rotation axis Ax1. That is, at least the outer peripheral surface of the casing 10 is a perfect circle centered on the rotation axis Ax1 in a plan view (viewed from one side in the direction of the rotation axis Ax1 ). The casing 10 is formed in a cylindrical shape with both end faces in the direction of the rotation axis Ax1 opened. Here, the gear main body 22 of the internal gear 2 is seamlessly integrated with the housing 10, and the housing 10 and the gear main body 22 are handled as one piece. Therefore, the inner peripheral surface of the housing 10 includes the inner peripheral surface 221 of the gear main body 22 . In addition, the outer ring 62 of the bearing member 6A is fixed to the housing 10 . That is, the outer ring 62 of the first bearing member 601A is fixed by fitting to the input side (the left side in FIG. 11 ) of the rotation axis Ax1 viewed from the gear main body 22 on the inner peripheral surface of the housing 10 . On the other hand, the outer ring 62 of the second bearing member 602A is fitted and fixed to the output side (the right side in FIG. 11 ) of the rotation axis Ax1 viewed from the gear main body 22 on the inner peripheral surface of the housing 10 .

Also, the end face of the housing 10 on the input side (left side in FIG. 11 ) of the rotation axis Ax1 is closed by the carrier flange 18 , and the end surface of the housing 10 on the output side (right side in FIG. 11 ) of the rotation axis Ax1 is closed. The end face is blocked by the output flange 19. Therefore, as shown in FIG. 11 and FIG. 12, the planetary gear 3, a plurality of inner pins 4, a plurality of pins 23, and an eccentric body bearing 5 are housed in the space surrounded by the housing 10, the planet carrier flange 18, and the output flange 19. and other parts. Here, the oil seal 161 closes the gap between the planet carrier flange 18 and the housing 10 , and the oil seal 162 closes the gap between the output flange 19 and the housing 10 . The space sealed by the plurality of oil seals 14 , 15 , 161 , 162 constitutes the lubricant holding space 17 (see FIG. 11 ) in the same manner as the basic structure. A plurality of installation holes 111 for fixing the housing 10 itself are formed on both end surfaces of the housing 10 in a direction parallel to the rotation axis Ax1.

As another fourth point of difference, the gear device 1A of the present embodiment includes a plurality of planetary gears 3 . Specifically, the gear device 1A includes two planetary gears 3 , a first planetary gear 301 and a second planetary gear 302 . The two planetary gears 3 are arranged to face each other in a direction parallel to the rotation axis Ax1 (with the support ring 8A interposed therebetween). That is, the planetary gear 3 includes a first planetary gear 301 and a second planetary gear 302 aligned in a direction parallel to the rotation axis Ax1.

These two planetary gears 3 (the first planetary gear 301 and the second planetary gear 302 ) are arranged around the rotation axis Ax1 with a phase difference of 180 degrees. In the example of FIG. 11, among the first planetary gear 301 and the second planetary gear 302, the center C1 of the first planetary gear 301 located on the input side of the rotation axis Ax1 (the left side of FIG. 11 ) is at a position relative to the rotation axis Ax1. The state shifted (offset) to the top of the figure. On the other hand, the center C2 of the second planetary gear 302 located on the output side of the rotation axis Ax1 (the right side in FIG. 11 ) is shifted (offset) downward in the figure with respect to the rotation axis Ax1 . In this way, by arranging the plurality of planetary gears 3 equally in the circumferential direction centering on the rotation axis Ax1 , weight balance among the plurality of planetary gears 3 can be achieved. In the gear device 1A of the present embodiment, since weight balance is achieved among the plurality of planetary gears 3 in this way, the gap 75 of the eccentric shaft 7 is omitted (see FIG. 3 ).

More specifically, the eccentric shaft 7 has two eccentric portions 72 with respect to one shaft center portion 71 . The centers (central axes) of the two eccentric portions 72 coincide with the centers C1 and C2 shifted from the rotation axis Ax1, respectively. In addition, the shape itself of the first planetary gear 301 and the second planetary gear 302 is the same. Further, the eccentric body bearing 5 in the state of being mounted on the eccentric portion 72 around the center C1 is housed in the opening 33 of the first planetary gear 301 . The opening 33 of the second planetary gear 302 accommodates the eccentric body bearing 5 mounted on the eccentric portion 72 around the center C2. Here, the distance ΔL1 between the rotation axis Ax1 and the center C1 is the eccentricity of the first planetary gear 301 relative to the rotation axis Ax1, and the distance ΔL2 between the rotation axis Ax1 and the center C2 is the eccentricity of the second planetary gear 302 relative to the rotation axis Ax1. the amount of eccentricity.

18 and 19 show states of the first planetary gear 301 and the second planetary gear 302 at a certain moment. FIG. 18 is a sectional view taken along line A1 - A1 of FIG. 11 , showing the first planetary gear 301 . FIG. 19 is a sectional view taken along line B1 - B1 in FIG. 11 , showing the second planetary gear 302 . However, in FIGS. 18 and 19 , illustration of the holder 54 is omitted, and hatching is omitted even in cross-section. As shown in FIG. 18 and FIG. 19 , in the first planetary gear 301 and the second planetary gear 302 , the centers C1 and C2 are located at 180-degree rotationally symmetrical positions with respect to the rotation axis Ax1 . In the present embodiment, the eccentricity amount ΔL1 and the eccentricity amount ΔL2 are opposite to each other when viewed from the rotation axis Ax1, but have the same absolute value. According to the above configuration, the first planetary gear 301 and the second planetary gear 302 revolve around the rotation axis Ax1 with a phase difference of 180 degrees around the rotation axis Ax1 due to the rotation (autorotation) of the shaft center portion 71 around the rotation axis Ax1. Rotation (eccentric movement).

As another fifth difference, in this embodiment, as shown in FIG. 11 , the eccentric body bearing 5 is constituted by a roller bearing instead of the deep groove ball bearing described in the basic structure. That is, in the gear device 1A of the present embodiment, the eccentric body bearing 5 uses columnar (cylindrical) rollers as the rolling elements 53 . Furthermore, in this embodiment, the eccentric inner ring 51 (see FIG. 3 ) and the eccentric outer ring 52 (see FIG. 3 ) are omitted. Therefore, the inner peripheral surface of (the opening 33 of) the planetary gear 3 becomes the rolling surface of the plurality of rolling elements 53 instead of the eccentric outer ring 52 , and the outer peripheral surface of the eccentric portion 72 becomes the rolling surface of the plurality of rolling elements 53 instead of the eccentric inner ring 51 . rolling surface. In the present embodiment, the eccentric body bearing 5 has a cage (bearing cage) 54, and each of the plurality of rolling elements 53 is held by the cage 54 in a rotatable state. The cage 54 holds the plurality of rolling elements 53 at equal intervals in the circumferential direction of the eccentric portion 72 . Furthermore, the cage 54 is not fixed with respect to the planetary gear 3 and the eccentric shaft 7 , but is relatively rotatable with respect to the planetary gear 3 and the eccentric shaft 7 . Accordingly, the plurality of rolling elements 53 held by the cage 54 move in the circumferential direction of the eccentric portion 72 as the cage 54 rotates.

As another sixth difference, as shown in FIG. 11 , a gear device 1A of this embodiment includes a support ring 8A instead of the support body 8 . The support ring 8A is arranged between the two planetary gears 3 , the first planetary gear 301 and the second planetary gear 302 . The support ring 8A has an annular shape in which at least the outer peripheral surface is a perfect circle when viewed from above. Furthermore, the position of the support ring 8A is restricted by bringing the outer peripheral surface into contact with the plurality of pins 23 of the internal gear 2 . Since the plurality of pins 23 constitute the internal teeth 21 of the internal gear 2 , in other words, the support ring 8A is positionally restricted by bringing the outer peripheral surface into contact with the internal teeth 21 . Here, the diameter of the outer peripheral surface of the support ring 8A is the same as the diameter of an imaginary circle (addendum circle) passing through the tips of the internal teeth 21 of the internal gear 2 . Therefore, all of the plurality of pins 23 are in contact with the outer peripheral surface of the backup ring 8A. Therefore, in a state where the position of the support ring 8A is restricted by the plurality of pins 23 , the position of the support ring 8A is restricted so that the center of the support ring 8A coincides with the center of the internal gear 2 (rotation axis Ax1 ).

Here, the support ring 8A is sandwiched between the first planetary gear 301 and the second planetary gear 302 , and rotates around the rotation axis Ax1 as the planetary gear 3 rotates (autorotates). At this time, the support ring 8A rotates while its outer peripheral surface is in contact with the plurality of pins 23 , so the plurality of pins 23 each rotate (rotate) along with the rotation of the support ring 8A. Therefore, the support ring 8A constitutes a needle bearing (needle roller bearing) together with the internal gear 2 and rotates smoothly. That is to say, if the gear main body 22 of the internal gear 2 is regarded as an "outer ring" and the support ring 8A is regarded as an "inner ring", the plurality of pins 23 between the two serve as "rolling elements (rollers"). )" function. In this way, the support ring 8A constitutes a needle bearing together with the internal gear 2 (the gear main body 22 and the plurality of pins 23 ), and can rotate smoothly. In addition, since the support ring 8A sandwiches the plurality of pins 23 between the gear body 22 and the gear body 22, the support ring 8A also functions as a "stopper" that prevents the movement of the pins 23 in the direction away from the inner peripheral surface 221 of the gear body 22. .

As another seventh point of difference, as shown in FIG. 11 , the gear device 1A of the present embodiment includes a spacer 55 . The spacer 55 is arranged between the first bearing 91 and the second bearing 92 which are inner bearing members and the eccentric body bearing 5 . Specifically, the spacers 55 are disposed between the first bearing 91 and the eccentric body bearing 5 on the first planetary gear 301 side, and between the second bearing 92 and the eccentric body bearing 5 on the second planetary gear 302 side. The spacer 55 has an annular shape in which at least the inner peripheral surface is a perfect circle when viewed from above. The spacer 55 functions as a "pressor" of the eccentric bearing 5, and restricts the movement of the eccentric bearing 5 (especially the cage 54) in a direction parallel to the rotation axis Ax1.

Here, the spacer 55 secures clearances with respect to the outer rings of the first bearing 91 and the second bearing 92 . Therefore, in the first bearing 91 and the second bearing 92 , their outer rings are not in contact with the spacer 55 , and only their inner rings are in contact with the spacer 55 . On the other hand, the first bearing member 601A and the second bearing member 602A, which are the bearing member 6A, ensure a clearance with the planetary gear 3 . Therefore, the first bearing member 601A and the second bearing member 602A are not in contact with the planetary gear 3 .

As another eighth point of difference, the gear device 1A of the present embodiment is configured such that a preload is applied to each inner pin 4 from the planetary gear 3 when the plurality of inner pins 4 do not rotate relative to the inner gear 2 . That is, in the gear device 1A, when the plurality of inner pins 4 do not rotate relative to the inner gear 2, the inner peripheral surfaces 321 of the plurality of inner pin holes 32 are pressed against each of the plurality of inner pins 4 to form multiple inner pins 4. Each domestic pin 4 acts as a preload respectively. Here, the gear unit 1A supports the plurality of inner pins 4 by the support structure 40 (rolling bearings 41 , 42 ), respectively, so as to maintain a state where a preload acts. The support structure 40 supports each of the plurality of inner pins 4 so as to cancel out moments generated in each of the plurality of inner pins 4 due to preloading.

According to this configuration, in the gear device 1A of the present embodiment, the inner pin 4 is always in contact with the planetary gear 3 at a part of the inner peripheral surface 321 of the inner pin hole 32 , and the inner pin 4 is less likely to be separated from the planetary gear 3 . Therefore, when the gear unit 1A is driven, the inner pin 4 revolves in the inner pin hole 32 while being pressed against the inner peripheral surface 321 of the inner pin hole 32 . Generally, in consideration of assembly tolerances, etc., when the gear unit is assembled, a gap is ensured between the inner peripheral surface of the inner pin hole and the inner pin when the gear unit is not driven. Eliminate that gap. Therefore, according to the gear device 1A of the present embodiment, at least the backlash caused by the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 can be reduced or eliminated, thereby easily suppressing the angle transmission error to be small. . Especially in the gear unit 1A with a high reduction ratio, the error of the rotation of the output side (output flange 19 ) relative to the rotation of the input side (eccentric shaft 7 ), that is, the angular transmission, even due to backlash caused by a slight backlash The error also becomes larger, so the effect of reducing or eliminating backlash is larger.

In addition, in addition to the above aspects, for example, the number of teeth of the internal gear 2 and the planetary gear 3, the reduction ratio, the number of the internal pin hole 32 and the internal pin 4, and the specific shape and size of each part are also appropriately different in this embodiment and the basic structure. . For example, 18 inner pin holes 32 and 18 inner pins 4 are each provided in the basic structure, but 6 each are provided as an example in this embodiment.

Next, the structure around the inner pin 4 in the gear device 1A of this embodiment will be described in detail with reference to FIGS. 11 to 20 .

First, as a premise, in the gear device 1A of the present embodiment, the inner pin 4 moves (revolves) in the inner pin hole 32 with the eccentric movement of the planetary gear 3 . The amount of movement of the inner pin 4 at this time is twice the amount of eccentricity ΔL1 (ΔL2) in the linear direction (for example, the vertical direction in FIG. 11 ) perpendicular to the rotation axis Ax1. That is, ideally, the diameter Di of the inner pin hole 32 is expressed by the diameter di of the inner pin 4 as "Di=di+2ΔL1". Therefore, the inner pin 4 is inserted into the inner pin hole 32 with a margin of space (gap) secured between the inner peripheral surface 321 of the inner pin hole 32 . However, it is difficult for the diameter di of the inner pin 4 and the diameter Di of the inner pin hole 32 to be the design value (ideal value), and subtle variations occur within the tolerance range. For example, if the diameter di of the inner pin 4 is smaller than the design value, the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 becomes large, backlash due to the gap occurs, and the angular transmission error increases. Conversely, if the diameter di of the inner pin 4 is larger than the design value, the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 becomes smaller, and the torque (input torque) required to rotate the eccentric shaft 7 becomes larger, The loss of the gear unit 1A becomes large.

Here, in this embodiment, as described above, at least in the state where the bearing member 6A, the internal gear 2 and the planetary gear 3 are combined, each of the plurality of internal pins 4 can be detached through the internal pin path Sp1. That is, in the gear device 1A, at least the bearing member 6A, the internal gear 2 and the planetary gear 3 can be removed without disassembling (disassembling) the plurality of inner pins 4 . Here, the inner pin passage Sp1 is located on at least one side in a direction parallel to the rotation axis Ax1 with respect to the plurality of inner pins 4, and therefore the inner pins 4 are moved through the inner pin passage Sp1 so as to move in a direction parallel to the rotation axis Ax1. remove.

In other words, with respect to the plurality of inner pins 4, at least one side in the direction parallel to the rotation axis Ax1 can be opened by the inner pin passage Sp1, and therefore, the plurality of inner pins 4 can be respectively disassembled through the opened portion (inner pin passage Sp1). Down. In addition, by detaching the inner pin 4, the inner pin 4 can be replaced or the like. That is, after removing the inner pin 4, by reassembling another inner pin 4 or the same inner pin 4 after maintenance (grinding or cleaning, etc.), at least in the state where the bearing member 6A, the inner gear 2 and the planetary gear 3 are combined , the replacement of the domestic pin 4 and the like can be performed. The reassembled inner pin 4 is also inserted through the inner pin passage Sp1 in the same manner as when it was disassembled.

In short, according to the above configuration, in the gear device 1A of the present embodiment, at least the inner pin 4 can be replaced without disassembling the bearing member 6A, the inner gear 2 , and the planetary gear 3 . Therefore, for example, when the diameter di of the inner pin 4 is smaller than the design value, by replacing the inner pin 4 with a larger diameter, at least the gap caused by the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 can be reduced or eliminated. Backlash, so it is easy to suppress the angle transmission error to be small. Conversely, when the diameter di of the inner pin 4 is larger than the design value, by replacing the inner pin 4 with a smaller diameter, the input torque required to rotate the eccentric shaft 7 can be suppressed to be small, and the gear unit 1A can be easily adjusted. Losses are kept to a minimum. Especially in the gear unit 1A with a high reduction ratio, the error of the rotation of the output side (output flange 19 ) relative to the rotation of the input side (eccentric shaft 7 ), that is, the angular transmission, even due to backlash caused by a slight backlash The error also becomes larger, so the effect of reducing or eliminating backlash is large.

Furthermore, according to the structure of the present embodiment, the angle transmission error at the time of starting rotation of the gear unit 1A from a stopped state can be reduced, so that the starting characteristics as the gear unit 1A can be greatly improved, and the speed at which the gear unit 1A starts or rotates can be greatly improved. Responsiveness when switching orientations. As a result, the use of the gear device 1A can exhibit sufficient characteristics in a field where stops, starts, and rotation directions are frequently switched, such as in the robotics field, and where angular transmission errors are strictly required.

Furthermore, in the present embodiment, each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state. However, each inner pin 4 is not strictly directly held by the inner ring 61, but is indirectly held by (via the rolling bearings 41, 42) the planetary carrier flange 18 and the output flange 19 integrated with the inner ring 61. It is held by the inner ring 61 of the bearing member 6A. In this way, the structure in which the inner pin 4 is held so as to be able to rotate, the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 is small, and even if the inner pin 4 is pressed against the inner peripheral surface 321 of the inner pin hole 32, the inner pin 4 The inside of the hole 32 revolves, and the inner pin 4 also rolls with respect to the inner peripheral surface 321 of the inner pin hole 32 . In other words, the inner pin 4 revolves in the inner pin hole 32 by rolling on the inner peripheral surface 321 of the inner pin hole 32 , so loss due to frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 hardly occurs.

Furthermore, a plurality of inner pins 4 are arranged inside the inner ring 61 (of the bearing member 6A) when viewed in a direction parallel to the rotation axis Ax1 . That is, the plurality of inner pins 4 are arranged inside the bearing member 6A (the first bearing member 601A and the second bearing member 602A). As described above, since the plurality of inner pins 4 are arranged inside the bearing member 6A, the inner pins 4 can be removed only by securing the inner pin passage Sp1 inside the bearing member 6A. Specifically, holes for inserting a plurality of inner pins 4 are formed on the carrier flange 18 and the output flange 19 inside the bearing member 6A, and by opening at least one of the holes in the direction parallel to the rotation axis Ax1, it is possible to achieve Channel Sp1 for domestic sales. According to this configuration, it is possible to suppress an increase in the size of the gear unit 1A in the radial direction (direction perpendicular to the rotation axis Ax1).

In addition, in the gear device 1A of the present embodiment, as shown in FIG. 15 , the inner pin path Sp1 is located on both sides in the direction parallel to the rotation axis Ax1 with respect to the plurality of inner pins 4 . That is, when viewed from the plurality of inner pins 4, both the input side (left side in FIG. 15 ) of the rotation axis Ax1 and the output side (right side in FIG. 15 ) of the rotation axis Ax1 can be opened through the inner pin path Sp1. . Therefore, each of the plurality of inner pins 4 can be detached from any one of the input side and the output side of the rotary shaft Ax1 . In addition, it is also possible to push the existing inner pin 4 from one direction parallel to the rotation axis Ax1 and detach the inner pin 4 from the other direction parallel to the rotation axis Ax1. Therefore, when replacing the inner pin 4, for example, the existing inner pin 4 is pushed with a new inner pin 4 from the input side of the rotary shaft Ax1, so that a new one can be inserted while detaching the existing inner pin 4 from the output side of the rotary shaft Ax1. domestic sales4.

In addition, in the present embodiment, the internal pin path Sp1 is not always open, but is covered by the

lids

163 and 164 at least when the gear unit 1A is used. The

covers

163, 164 are detachably mounted with respect to the planet carrier flange 18 and the output flange 19, for example. Specifically, the cover body 163 is detachably attached to the carrier flange 18 , and covers the internal pin path Sp1 on the input side of the rotation axis Ax1 while being attached to the carrier flange 18 . The cover body 164 is detachably attached to the output flange 19 , and covers the internal pin path Sp1 on the output side of the rotation axis Ax1 in a state attached to the output flange 19 .

In short, the gear device 1A of this embodiment further includes

covers

163 , 164 . The

lids

163 and 164 are movable between a first position covering the internal pin path Sp1 and a second position exposing the internal pin path Sp1. In this embodiment, the state in which the

covers

163 and 164 are mounted on the planetary carrier flange 18 and the output flange 19 (the state in FIGS. 11 and 12 ) corresponds to the "first position", and the The state where the flange 19 is removed (the state of FIG. 15 ) corresponds to the "second position". The

covers

163 and 164 need only be movable between the first position and the second position, and are not necessarily detachable from the carrier flange 18 and the output flange 19 .

In addition, the

lids

163 and 164 collectively cover the plurality of inner pin paths Sp1 corresponding to the plurality of inner pins 4 at the first position. That is, in this embodiment, since six inner pins 4 are provided as an example, six paths Sp1 for inner pins are also provided on the input side and the output side of the rotation axis Ax1 respectively. The cover body 163 does not cover the six internal pin paths Sp1 on the input side of the rotation axis Ax1 one by one, but covers them collectively. Similarly, the cover body 164 does not individually cover the six paths Sp1 for inner pins on the output side of the rotation axis Ax1 one by one, but covers them collectively. Therefore, when the cover body 163 is removed, as shown in FIG. 16, the six internal pin paths Sp1 on the input side of the rotation axis Ax1 are exposed. When the cover body 164 is removed, as shown in FIG. 17, the output of the rotation axis Ax1 The six internal pins on the side are exposed by the path Sp1.

Specifically, each of the

lids

163 and 164 has an annular shape in which the outer peripheral surface and the inner peripheral surface are perfect circles in plan view. Furthermore, the positions of the

cover bodies

163 and 164 are restricted by bringing their outer peripheral surfaces into contact with the carrier flange 18 and the output flange 19 . That is, the carrier flange 18 and the output flange 19 respectively have recesses that open toward the outside in a direction parallel to the rotation axis Ax1 . The

cover bodies

163 and 164 are attached to the carrier flange 18 and the output flange 19 so as to fit into these recesses. In addition, the oil seals 14 and 15 are fitted inside the

lid bodies

163 and 164 . That is, the

lids

163 , 164 are combined with the oil seals 14 , 15 so that their inner peripheral surfaces are in contact with the outer peripheral surfaces of the oil seals 14 , 15 , respectively. Therefore, the positions of the oil seals 14 and 15 when viewed from a direction parallel to the rotation axis Ax1 are restricted by the

lids

163 and 164 .

In this embodiment, as shown in FIG. 13 and FIG. 14 as an example, the

covers

163 and 164 are attached to the carrier flange 18 and the output flange 19 by a plurality of (six as an example) mounting screws 160 . That is to say, the cover body 163 is fixed to the planet carrier by fastening six mounting screws 160 to the threaded holes 183 (see FIG. 16 ) of the planet carrier flange 18 in the state of being inserted into the depression of the planet carrier flange 18 Flange18. The cover body 164 is fixed to the output flange 19 by fastening the six mounting screws 160 to the threaded holes 193 (see FIG. 17 ) of the output flange 19 while being fitted into the recess of the output flange 19 . The materials of the

cover bodies

163 and 164 are the same as other parts, such as stainless steel, cast iron, carbon steel for mechanical structure, chrome-molybdenum steel, phosphor bronze or aluminum bronze.

As shown in FIG. 13 , an opening hole 165 is formed in the lid body 163 . The opening holes 165 are provided at respective positions corresponding to the carrier bolts 181 in a state where the cover body 163 is attached to the carrier flange 18 . In this embodiment, since there are six carrier bolts 181, six opening holes 165 are also provided. The opening hole 165 functions as an escape hole for avoiding the heads of the carrier bolts 181 . In addition, as shown in FIG. 14 , an opening hole 166 is formed in the lid body 164 . The opening holes 166 are provided at respective positions corresponding to the flange bolt holes 192 in a state where the cover body 164 is attached to the output flange 19 . In this embodiment, since there are six flange bolt holes 192, six opening holes 166 are also provided. The opening hole 166 functions as a through hole exposing the flange bolt hole 192 .

Thus, in this embodiment, the mounting screws 160 for mounting the cover body 163 to the planetary carrier flange 18 are provided separately from the planetary carrier bolts 181 for fixing the planetary carrier flange 18 to the output flange 19 . Therefore, the cover body 163 can be detached from the carrier flange 181 by removing the mounting screws 160 while the carrier flange 181 is fixed to the output flange 19 by the carrier bolts 181 . However, it is not limited to this structure, and the carrier bolts 181 for fixing the carrier flange 18 to the output flange 19 may also be used for attaching the cover body 163 to the carrier flange 18 . In this case, the mounting screws 160 are omitted, the carrier flange 18 is fixed to the output flange 19 by the carrier bolts 181 , and the cover 163 is attached to the carrier flange 18 .

In addition, in this embodiment, a positioning structure for relatively positioning the

cover bodies

163 , 164 and the inner ring 61 is also included. As an example, the positioning structure is composed of a convex portion 167 (see FIG. 15 ) and concave portions 184 and 194 (see FIGS. 16 and 17 ). Concretely, convex portions 167 are respectively provided on opposing surfaces of the

cover bodies

163 , 164 that face the carrier flange 18 and the output flange 19 .

Recesses

184 , 194 are respectively provided on the surfaces of the carrier flange 18 and the output flange 19 that face the covers 163 , 164 (that is, bottom surfaces of the depressions) at positions corresponding to the protrusions 167 . The cover body 163 is opposed to the inner ring 61 of the first bearing member 601A integrated with the carrier flange 18 by being combined with the carrier flange 18 so that the protrusion 167 is fitted into the recess 184 of the carrier flange 18 . location. Similarly, the cover body 164 is opposed to the inner ring 61 of the second bearing member 602A integrated with the output flange 19 by being combined with the output flange 19 by fitting the convex portion 167 into the concave portion 194 of the output flange 19 . location.

By having such a positioning structure, the relative positions of the

lids

163 , 164 with respect to the inner ring 61 can be determined with high precision. That is, when viewed from a direction parallel to the rotation axis Ax1, the positions of the

lids

163 and 164 can be specified with high precision. In this embodiment, the positions of the oil seals 14 and 15 are restricted by the

covers

163 and 164 especially when viewed from a direction parallel to the rotation axis Ax1. Therefore, by improving the positional accuracy of the

covers

163 and 164, it is possible to suppress the oil seals 14 and 15 from 15 for poor centering. As a result, leakage of the lubricant from the lubricant holding space 17 sealed by the oil seals 14 and 15 is easily suppressed.

In addition, it is preferable to uniquely determine the relative positions of the

lids

163 , 164 and the inner ring 61 in the rotational direction centering on the rotational axis Ax1 by the positioning structure. As a result, the

covers

163 and 164 are assembled with respect to the inner ring 61 of the bearing member 6A in a non-rotational symmetry, that is, 360-degree rotational symmetry with respect to the rotation axis Ax1 as an axis of symmetry. In the present embodiment, as an example, as shown in FIG. 16 , when viewed from the input side of the rotation axis Ax1, the recesses 184 of the carrier flange 18 are provided in a plurality of ( here are two). Similarly, as shown in FIG. 17 , when viewed from the output side of the rotation axis Ax1 , the output flange 19 has a plurality of recesses 194 (two here) at positions that are not rotationally symmetrical with the rotation axis Ax1 as the axis of symmetry. As a result, the relative positional accuracy of the

lids

163 and 164 with respect to the inner ring 61 is further improved.

In addition, in this embodiment, each of the plurality of inner pins 4 is held by the inner ring 61 (of the bearing member 6A) at the same position as that of the bearing member 6A in a direction parallel to the rotation axis Ax1 . That is, as shown in FIG. 15 , a plurality of sets of rolling

bearings

41, 42 as a support structure 40 for holding (supporting) the inner pin 4 are at least partially located in a direction parallel to the rotation axis Ax1 with the first bearing member 601A and the second bearing member 601A. Where parts 602A overlap. That is, in a direction parallel to the rotation axis Ax1, at least a part of the rolling bearing 41 is located at the same position as the first bearing member 601A, and at least a part of the rolling bearing 42 is located at the same position as the second bearing member 602A. In particular, in the present embodiment, the dimensions in the width direction (direction parallel to the rotation axis Ax1 ) of the first bearing member 601A and the second bearing member 602A are substantially the same as the dimensions in the width direction of the rolling

bearings

41 and 42 . Therefore, in a direction parallel to the rotation axis Ax1, the first bearing member 601A and the second bearing member 602A substantially fall within the respective ranges of the rolling

bearings

41, 42, respectively. In other words, the first bearing member 601A and the second bearing member 602A are respectively arranged on the outer sides of the rolling

bearings

41 and 42 .

Thus, in this embodiment, the space originally provided inside the bearing member 6A (the first bearing member 601A and the second bearing member 602A) of the gear unit 1A is used as an installation space for the support structure 40 indicating the inner pin 4 . Therefore, it is possible to suppress an increase in size of the gear device 1A in a direction parallel to the rotation axis Ax1 due to the provision of the support structure 40 .

In particular, in this embodiment, the support structure 40 (rolling bearings 41, 42) is disposed outside the inner bearing members (the first bearing 91 and the second bearing 92) and the bearing member 6A (the first bearing member 601A and the second bearing member 602A) inside. In other words, the rolling

bearings

41 and 42 are arranged using the space between the inner bearing members (the first bearing 91 and the second bearing 92 ) and the bearing member 6A (the first bearing member 601A and the second bearing member 602A). Therefore, it is also possible to suppress an increase in the size of the gear unit 1A in the radial direction (direction perpendicular to the rotation axis Ax1 ) due to the provision of the rolling

bearings

41 , 42 .

In addition, the internal pin path Sp1 communicates with a lubricant holding space 17 that holds lubricant. Specifically, the path Sp1 for the inner pin is connected to the lubricant holding space 17 through holes for insertion of the inner pin 4 in the carrier flange 18 and the output flange 19 . According to this configuration, when replacing the inner pin 4 and the like, the lubricant can be replenished from the inner pin path Sp1 to the lubricant holding space 17 .

However, in the present embodiment, the pair of rolling

bearings

41 and 42 hold both ends in the longitudinal direction of the inner pin 4 in a state where the inner pin 4 can rotate. Here, as shown in FIG. 20 , each rolling

bearing

41 , 42 has a cage (bearing cage) 401 and a plurality of rolling elements 402 . The outer rings 403 of the rolling

bearings

41 and 42 also serve as the carrier flange 18 and the output flange 19 . Specifically, the inner peripheral surfaces of the holes for inserting the inner pins 4 in the carrier flange 18 and the output flange 19 function as the outer rings 403 of the rolling

bearings

41 , 42 . The outer ring 403 is perfectly circular in plan view, and the inner diameter of the outer ring 403 is one turn larger than the diameter (outer diameter) of the inner pin 4 , so a gap is formed between the outer ring 403 and the outer peripheral surface of the inner pin 4 . A plurality of rolling elements 402 are arranged in the gap between the outer ring 403 and the inner pin 4 . A plurality of rolling elements 402 are arranged in line in the circumferential direction of the outer ring 403 . All of the plurality of rolling elements 402 are metal parts of the same shape, and are arranged at equal intervals over the entire area of the outer ring 403 in the circumferential direction. The cage 401 holds a plurality of rolling elements 402 at equal intervals in the circumferential direction of the outer ring 403 .

In this embodiment, each rolling

bearing

41, 42 is a needle bearing (needle roller bearing) as an example. That is, each rolling

bearing

41 , 42 has a cylindrical roller as the rolling element 402 . Furthermore, the axes of the cylindrical rolling elements 402 are all arranged in parallel to the rotation axis Ax1. In this embodiment, each rolling

bearing

41, 42 does not have an inner ring, and the inner pin 4 functions as an inner ring. Therefore, with the

respective rolling bearings

41 and 42, the inner pin 4 rotates relative to the outer ring 403 due to the rolling of the plurality of rolling elements 402, and the

respective rolling bearings

41 and 42 can hold the inner pin 4 so as to be rotatable.

According to this configuration, the inner pin 4 can rotate by itself, and it is difficult to generate a loss due to frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 , so the inner roller can be omitted. Therefore, in the present embodiment, the inner pin 4 without the inner roller is inserted into the inner pin hole 32 so that the inner pin 4 directly contacts the inner peripheral surface 321 of the inner pin hole 32 . Thereby, the inner roller can be omitted, and the diameter of the inner pin hole 32 can be suppressed to be small, so that the planetary gear 3 can be downsized (in particular, the diameter can be downsized), and the overall gear device 1A can also be easily downsized. Furthermore, each inner pin 4 is held by a pair of rolling

bearings

41,42. Therefore, when the inner pin 4 rotates, losses caused by frictional resistance between the inner pin 4 and the planet carrier flange 18 and the output flange 19 are less likely to occur.

On the other hand, the arrangement of the plurality of sets of rolling

bearings

41 and 42 viewed from a direction parallel to the rotation axis Ax1 is basically the same as the arrangement of the plurality of inner pins 4 . That is, as shown in FIGS. 18 and 19 , when viewed from a direction parallel to the rotation axis Ax1, when a virtual circle VC1 passing through the respective centers of the plurality of inner pins 4 is set, the plurality of sets of rolling

bearings

41, 42 Arranged on this imaginary circle VC1. In this embodiment, especially as shown in FIG. 20 , a plurality of sets of rolling

bearings

41 , 42 are arranged at equal intervals in the circumferential direction around the rotation axis Ax1 when viewed in a direction parallel to the rotation axis Ax1 . In FIG. 20 , the arrangement of the rolling bearing 41 is shown, but the arrangement of the rolling bearing 42 is also the same. In addition, in FIG. 20, even if it is a cross section, hatching is appropriately omitted.

That is, multiple sets of rolling

bearings

41 , 42 are arranged at equal intervals in the circumferential direction of virtual circle VC1 on virtual circle VC1 . That is to say, viewed from a direction parallel to the rotation axis Ax1, the imaginary circle VC1 passes through the respective centers of a plurality of rolling bearings 41 (or 42), and the distance on the imaginary circle VC1 between two adjacent rolling bearings 41 (or 42) It is equal among the plurality of rolling bearings 41 (or 42). According to this arrangement, the plurality of inner pins 4 are held by the plurality of sets of rolling

bearings

41 , 42 , and the force applied to the plurality of inner pins 4 can be evenly distributed when the gear unit 1A is driven.

Furthermore, in this embodiment, as shown in FIG. 20 , when viewed from a direction parallel to the rotation axis Ax1 , the center of a virtual circle VC1 passing through the centers of the plurality of sets of rolling

bearings

41 , 42 coincides with the rotation axis Ax1 . In other words, the center of the virtual circle VC1 is the same as the center of the gear body 22 of the internal gear 2 or the center of the pitch circle of the internal teeth 21 , and is located on the rotation axis Ax1 . According to this configuration, the center of the gear main body 22 of the internal gear 2 and the rotation center of the plurality of internal pins 4 with respect to the internal gear 2 are easily maintained on the rotation axis Ax1 with high precision. As a result, in the gear device 1A, there is an advantage that troubles such as occurrence of vibration due to poor centering and reduction in transmission efficiency are less likely to occur.

Next, the force (preload) that acts on the inner pins 4 when the plurality of inner pins 4 do not rotate relative to the inner gear 2 , that is, when the gear unit 1A is not driven, will be described in more detail. Both ends of each inner pin 4 are held by a pair of rolling

bearings

41 , 42 . Each rolling

bearing

41, 42 maintains a state in which a plurality of rolling elements 402 are pressed against the outer peripheral surface of each inner pin 4. As shown in FIG. As a result, the "preload" acting on the inner pin 4 from the

respective rolling bearings

41, 42 is maintained.

The above-mentioned preload is realized by a negative gap (minus gap) provided between the inner pin 4 and the plurality of rolling elements 402 . The "negative clearance" in the present disclosure is a so-called "interference amount", and refers to a relationship in which the two overlap (press) each other through assembly between the two as designed. That is to say, when the inner pin 4 is assembled with the rolling

bearings

41, 42, by setting the gap to be 0 or less, the state in which the plurality of rolling elements 402 are pressed against the inner pin 4 is realized so as to avoid positive contact between the inner pin 4 and the plurality of rolling elements 402. gap. As a result, the preload acts on the inner pin 4 from the plurality of rolling elements 402 in a state where the inner pin 4 is combined with the rolling

bearings

41 and 42 .

In this embodiment, as an example, the difference between the inner diameter of the outer ring 403 and the body diameter (diameter) of the inner pin 4 is not more than twice the body diameter (diameter) of the rolling element 402 . As a result, a negative clearance (interference) of 0 or more is generated between the inner pin 4 and the rolling elements 402 . As an example, the fitting tolerance of the inner pin 4 with respect to the rolling

bearings

41 and 42 is preferably "k6" or more, more preferably "p6". In short, the sets of rolling

bearings

41 , 42 each have a plurality of rolling elements 402 . A preload acts by pressing the plurality of rolling elements 402 against the plurality of inner pins 4, respectively.

In the present embodiment, negative clearances are uniformly set with respect to the rolling

bearings

41 and 42 for a plurality of (here, six) inner pins 4 . Therefore, the inner pin side preload acts on all the plurality of inner pins 4 from both the rolling

bearings

41 and 42 . However, this configuration is not an essential configuration of the gear unit 1A, and the inner pin side preload may not be applied to a part of the inner pin 4 .

In addition, in the present embodiment, not only the rolling

bearings

41 and 42 but also the planetary gear 3 act on the inner pin 4 with preload. That is, preload is also applied to the inner pin 4 from the planetary gear 3 by the negative clearance (minus clearance) provided between the inner pin 4 and the inner peripheral surface 321 of the inner pin hole 32 .

As described above, according to the structure of "preloading" the inner pin 4, the gap between the inner pin 4 and the rolling

bearings

41, 42 or the planetary gear 3 can be reduced or eliminated, and the rattling of the inner pin 4 caused by the gap can be suppressed. . As a result, according to the gear device 1A of this embodiment, the backlash caused by the clearance between the inner pin 4 and the rolling

bearings

41, 42 or the planetary gear 3 can be reduced or eliminated, and the angular transmission error can be easily suppressed to be small.

Next, the structure for improving the lubrication state of the inner pin 4 in the gear device 1A of the present embodiment will be described in detail with reference to FIGS. 21 to 24 .

As a premise, especially in the structure in which the inner pin 4 is preloaded by the above-mentioned negative clearance (negative clearance), lubrication failure is likely to occur particularly at the portion of the inner pin 4 where the preload is applied. If lubrication failure occurs, friction may occur between the rolling

bearings

41 and 42 or between the inner pin 4 and the inner peripheral surface 321 of the inner pin hole 32 when the inner pin 4 rotates, and this friction may become a loss in power transmission. Furthermore, when the gear device 1A is used for a long period of time, for example, the loss due to friction increases due to, for example, deterioration of the lubricant, which may hinder the life extension of the gear device 1A. Therefore, in the gear device 1A of the present embodiment, by adopting a structure for improving the lubrication state of the inner pin 4 , it is possible to realize the gear device 1A that easily reduces the loss generated when the inner pin 4 rotates.

As shown in FIG. 21 , the gear device 1A of the present embodiment includes, as a structure for improving the lubrication state of the inner pin 4 , a circulation path 170 including a gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 and The raceways 404 of the rolling elements 402 in the rolling

bearings

41 , 42 . In addition, in the gear unit 1A, the lubrication state of the inner pin 4 is improved by circulating the lubricant through the circulation path 170 . In FIG. 21 and the like, the flow (circulation) of the lubricant in the circulation path 170 is conceptually shown by dotted arrows.

Here, the raceways 404 of the rolling elements 402 in the rolling

bearings

41 and 42 refer to paths along which the rolling elements 402 move (roll). In this embodiment, as described above, since the planetary carrier flange 18 or the output flange 19 doubles as the outer ring 403, and the inner pin 4 functions as the inner ring, the distance between the planetary carrier flange 18 or the output flange 19 and the inner pin 4 is The gap between them constitutes the raceway 404 of the rolling element 402 . In other words, an annular raceway 404 centered on the central axis of the inner pin 4 is formed along the outer peripheral surface of the inner pin 4 . Based on such a raceway 404 , the path of the lubricant including the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 corresponds to the circulation path 170 .

In the present embodiment, the circulation path 170 is formed in the lubricant holding space 17 into which the lubricant is injected. By forming such a circulation path 170 , lubricant circulates through at least the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 and the raceway 404 of the rolling element 402 , thus improving the lubrication state of the inner pin 4 . That is to say, although the internal pin 4 is preloaded by the above-mentioned negative clearance, by actively circulating the lubricant, the "lubricant exhaustion" in which the lubricant is insufficient or exhausted around the inner pin 4 is less likely to occur. In the case of ", more than a certain amount of lubricant is always supplied. Moreover, compared with the structure in which the lubricant stagnates at a fixed position, by circulating the lubricant through the circulation path 170, the lubricant can be replaced at any time even at the part where the preloading action is performed in the inner pin 4, thereby suppressing the lubrication of the lubricant. deterioration.

Therefore, even in the part where the inner pin 4 is preloaded, the lubrication state is improved, and poor lubrication is less likely to occur. reduce. Therefore, even when the gear device 1A is used for a long period of time, the loss due to friction can be reduced, and the life extension of the gear device 1A can be easily achieved. As a result, in the gear device 1A of the present embodiment, there is an advantage that the loss generated when the inner pin 4 rotates can be easily reduced. In short, the gear device 1A according to the present embodiment is less prone to reliability degradation especially during long-term use, and thus can improve the transmission efficiency of the gear device 1A, prolong its service life, and improve its performance.

More specifically, in this embodiment, as shown in FIG. 22 , the lubricant is released in a direction parallel to the rotation axis Ax1 by contraction of the gap (between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 ). Push it away from planetary gear 3. FIG. 22 is an explanatory diagram schematically showing the flow of lubricant when focusing on the third region R3 among the first region R1 to the fourth region R4 .

That is, when the eccentric shaft 7 rotates to swing the planetary gear 3 , the inner pin 4 moves so as to revolve in the inner pin hole 32 while being inserted into the inner pin hole 32 formed in the planetary gear 3 . In this way, when the inner pin 4 revolves in the inner pin hole 32 , the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 repeatedly expands and contracts. That is, if we focus on the gap between the inner peripheral surface 321 of the inner pin hole 32 on the rotation axis Ax1 side (upper side in FIG. 22 ) and the inner pin 4 when viewed from the inner pin 4, the As it revolves, the gap shrinks (compresses) as shown on the right side of FIG. 22 from the state shown on the left side of FIG. 22 . Similarly, if we focus on the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 that exists on the opposite side (the lower side in FIG. 22 ) of the rotation axis Ax1 when viewed from the inner pin 4, the The gap shrinks (compresses) as shown in the left side of FIG. 22 from the state shown in the right side of FIG. 22 by revolution. As the inner pin 4 revolves, the state shown on the left side and the right side of FIG. 22 are alternately repeated, so the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 repeats expansion and contraction.

Then, when the gap shrinks, the lubricant that has entered the gap is pushed out from the gap toward the direction away from the planetary gear 3 in a direction parallel to the rotation axis Ax1 . In this way, the inner pin 4 revolving in the inner pin hole 32 constitutes a positive displacement pump such as a vane pump, and pushes the lubricant out of the gap with sufficient pressure, so that the lubricant can easily circulate in the circulation path 170 . FIG. 23 is a schematic diagram showing how the lubricant circulates through the circulation path 170 by the pump function 172 generated by the inner pin 4 revolving in the inner pin hole 32 . In this way, by providing the pump function 172 in the circulation path 170 , the lubricant circulates in the circulation path 170 at a certain flow rate, thereby improving the lubrication state of the inner pin 4 .

In particular, in this embodiment, as shown in FIG. 22 , when the eccentric shaft 7 rotates, the lubricant that moves away from the rotation axis Ax1 due to the centrifugal force easily reaches between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 . near the gap. That is, in the gear unit 1A with a high reduction ratio, since the eccentric shaft 7 as the input shaft rotates at a high speed, a large centrifugal force acts on the lubricant from the eccentric shaft 7, and the lubricant easily reaches the inner pin located around the eccentric shaft 7. 4. In this way, the lubricant reaching the vicinity of the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 is pushed out by the pump function 172 as described above, so that the lubricant easily circulates in the circulation path 170 .

In addition, the gear device 1A of the present embodiment includes

cover bodies

163 , 164 located on at least one side of the plurality of inner pins 4 in a direction parallel to the rotation axis. Here, as shown in FIGS. 21 and 22 , grooves 171 are formed in the

lids

163 and 164 , and the grooves 171 form a part of the circulation path 170 . The groove part 171 is provided in the surface which opposes the rolling

bearing

41, 42 of the cover body 163,164. The groove portion 171 expands the gap between the

cover bodies

163, 164 and the rolling

bearings

41, 42, and ensures a gap through which lubricant can pass between the

cover bodies

163, 164 and the rolling

bearings

41, 42. In this embodiment, as an example, the groove portion 171 is provided on the inner peripheral side of the annularly formed

lid bodies

163 and 164 . By forming such groove portion 171 , circulation path 170 can be provided with a relatively simple structure.

In addition, in the present embodiment, the groove portion 171 is formed continuously over the entire circumference of the

cover bodies

163 , 164 in the circumferential direction. Therefore, the groove portion 171 has an annular shape when viewed from the input side of the rotation axis Ax1. By forming such a groove portion 171 , the circulation path 170 communicates between the plurality of inner pins 4 . That is, the groove portion 171 is formed in an annular shape so as to connect the facing portions of the cover body 163 facing the plurality (six in this embodiment) of the inner pins 4 , and therefore, on the input side of the rotation axis Ax1 , the circulation path 170 communicates between the plurality of inner pins 4 through the groove portion 171 . Similarly, since the groove portion 171 is formed in an annular shape so as to connect the opposing portions of the cover body 164 facing the plurality (six in this embodiment) of the inner pins 4 , the output of the rotation axis Ax1 On the side, the circulation path 170 communicates between the plurality of inner pins 4 through the groove portion 171 . In this way, by forming the circulation path 170 communicating between the plurality of inner pins 4, the lubricant can be circulated in a wider range, and the lubrication state of the inner pins 4 can be further improved.

In addition, in the present embodiment, the circulation path 170 circulates the lubricant mainly in one direction. That is, as shown in FIGS. 21 to 23 and the like, the direction of the lubricant flowing through the circulation path 170 is fixed to one direction, and the lubricant flows in this one direction. The flow direction of the lubricant is determined by, for example, the direction of the centrifugal force acting on the lubricant when the eccentric shaft 7 rotates and the direction in which the lubricant is pushed out by the pump function 172 generated by the inner pin 4 revolving in the inner pin hole 32 . In this embodiment, as an example, as shown in FIG. 21, in the first region R1, the lubricant circulates counterclockwise in the circulation path 170 including the rolling bearing 41, and in the second region R2, the lubricant circulates in the circulation path 170 including the rolling bearing 42. Circulate counterclockwise in the circulation path 170. On the other hand, as shown in FIG. 21, in the third region R3, the lubricant circulates clockwise in the circulation path 170 including the rolling bearing 41, and in the fourth region R4, the lubricant circulates in the circulation path 170 including the rolling bearing 42. Cycle counterclockwise. Thereby, the flow of the lubricant in the circulation path 170 becomes smooth, and stagnation of the lubricant is less likely to occur, so that the lubrication state of the inner pin 4 can be further improved.

Here, as shown in FIG. 23 , at least a part of the inner peripheral surface of the circulation path 170 is provided with a direction restricting portion 173 for restricting the flow direction of the lubricant. That is, the circulation direction of the lubricant in the circulation path 170 is also regulated by the direction restricting portion 173 shown in FIG. 23 . For example, the direction restricting portion 173 may be formed on at least a part of the inner peripheral surface of the circulation path 170 such as the inner peripheral surface of the outer ring 403 or the surfaces of the grooves 171 of the

covers

163 and 164, or may be formed on the inner peripheral surface of the circulation path 170. The direction restricting portion 173 is integrally formed. As an example, the direction restricting part 173 is realized by imparting a fluid dynamic direction control function to at least a part of the inner peripheral surface of the circulation path 170 by laser machining or the like. By providing such a direction restricting portion 173 , the flow of the lubricant in the circulation path 170 becomes smooth and stagnation of the lubricant is less likely to occur, so that the lubrication state of the inner pin 4 can be further improved.

In addition, in this embodiment, as shown in FIG. 21 , the cross section including the rotation axis Ax1 is divided into a first block B1 on one side with respect to the rotation axis Ax1 and a second block B2 on the other side. Furthermore, the first block B1 is divided into a first region R1 on one side with respect to the planetary gear 3 and a second region R2 on the other side, and the second block B2 is divided into the above-mentioned one region with respect to the planetary gear 3 . The third region R3 on one side and the fourth region R4 on the other side. The circulation path 170 is provided in all of the first region R1, the second region R2, the third region R3, and the fourth region R4. In short, the cross section including the rotation axis Ax1 shown in FIG. 21 is divided into four regions of the first region R1 to the fourth region R4 by the rotation axis Ax1 and the planetary gear 3 . In FIG. 21, the first block B1 including the first region R1 and the second region R2 is located on the upper side of the rotation axis Ax1, and the second block B2 including the third region R3 and the fourth region R4 is located on the rotation axis Ax1. the underside of the In addition, the first region R1 and the third region R3 are regions located on the left side with respect to the planetary gear 3 , and the second region R2 and the fourth region R4 are regions located on the right side with respect to the planetary gear 3 .

By forming the circulation path 170 in all of the first region R1 to the fourth region R4 thus divided, it is possible to suppress deviation of the circulation path 170 in the gear device 1A. In other words, the circulation path 170 extends over the entire gear device 1A, and the lubrication state of the inner pin 4 can be improved throughout the entire gear device 1A.

Here, in this embodiment, the circulation path 170 circulates the lubricant between the first region R1 and the third region R3, and circulates the lubricant between the second region R2 and the fourth region R4 (see FIG. 28 ). . That is, in the present embodiment, as described above, the groove portion 171 forming a part of the circulation path 170 is formed continuously over the entire circumference of the

cover bodies

163 and 164, whereby the circulation path 170 is formed in a plurality of The domestic sales 4 are connected. Thus, the lubricant circulates between the first region R1 and the third region R3 located on both sides of the rotation axis Ax1, and also circulates between the second region R2 and the fourth region R4 located on both sides of the rotation axis Ax1. Accordingly, it is possible to improve the lubrication state of the inner pin 4 throughout the entire gear unit 1A.

In addition, as shown in FIG. 24 , at least one of the

lids

163 , 164 and the inner pin 4 is formed with a concave portion 174 that communicates with the circulation path 170 and holds lubricant. In this embodiment, as an example, the recessed part 174 is provided in the center part of the opposing surface of the inner pin 4 which opposes the cover body 163,164. The recess 174 expands the gap between the

cover bodies

163 , 164 and the inner pin 4 , and ensures a gap capable of retaining lubricant between the

cover bodies

163 , 164 and the recess 174 . By retaining the lubricant in the gap formed in this way, when the amount of lubricant in the circulation path 170 decreases, the lubricant can be supplied to the circulation path 170 , and the occurrence of lubricant exhaustion can be easily suppressed.

Next, the configuration around the input shaft (eccentric shaft 7 ) in the gear device 1A of this embodiment will be described in detail.

In the present embodiment, as described above, the gear unit 1A includes the bush 70 that is coupled to the input shaft (eccentric shaft 7 ) that eccentrically oscillates the planetary gear 3 and rotates together with the input shaft (eccentric shaft 7 ). . The bushing 70 has a fixing structure 701 for fixing a mating part.

According to the above configuration, in the gear device 1A of the present embodiment, the mating member is not directly fixed to the input shaft such as the eccentric shaft 7 , but the mating member is fixed via the bush 70 coupled to the input shaft. Therefore, the outer diameter of the input shaft (shaft center portion 71 of the eccentric shaft 7 ) can be reduced compared to the case where the mating member is directly fixed to the end surface of the input shaft. As a result, it is possible to provide the gear device 1A which can be easily downsized. In particular, in the gear unit 1A with a high reduction ratio, the rotation input from the mating member to the input shaft may be high-speed, and the connection between the input shaft and the mating member is required to be relatively strong. According to the configuration of the present embodiment, since the mating member is fixed to the fixing structure 701 of the bush 70, it can be relatively firmly coupled to the input shaft without increasing the outer diameter of the input shaft.

Specifically, the bushing 70 has a cylindrical shape in which at least the inner peripheral surface is a perfect circle in plan view. The center (central axis) of the bush 70 coincides with the rotation axis Ax1. An end portion of the bush 70 on the output side of the rotation axis Ax1 constitutes an insertion opening 702 (see FIG. 12 ) whose inner diameter is enlarged. The inner diameter of the insertion port 702 is substantially the same as the outer diameter of the axial center portion 71 of the eccentric shaft 7 . Thereby, the bush 70 can be coupled to the eccentric shaft 7 by fitting the end portion on the input side of the rotation axis Ax1 of the axial center portion 71 of the eccentric shaft 7 into the insertion port 702 . That is, in the present embodiment, the bush 70 has an insertion opening 702 and is coupled to the input shaft in a state where a part of the input shaft (eccentric shaft 7 ) is inserted into the insertion opening 702 . The material of the bushing 70 is the same as other parts, and is metals such as stainless steel, cast iron, carbon steel for mechanical structure, chrome-molybdenum steel, phosphor bronze or aluminum bronze.

In addition, in a state where a part of the eccentric shaft 7 is inserted (fitted) into the insertion port 702 , the bush 70 is coupled to the eccentric shaft 7 by press fitting. Furthermore, the bush 70 is coupled to the input shaft at least by bonding. Specifically, the bush 70 is firmly bonded to the eccentric shaft 7 with an adhesive applied to the inner peripheral surface of the insertion port 702 . In short, in the present embodiment, the bush 70 is coupled to the input shaft (eccentric shaft 7 ) by both press fitting and bonding. As a result, a firm connection between the bush 70 and the eccentric shaft 7 is achieved.

Furthermore, the outer diameter of the bush 70 is at least larger than the outer diameter of the axial center portion 71 of the eccentric shaft 7 . Therefore, in the state where the bush 70 is coupled to the eccentric shaft 7 , the bush 70 protrudes in a flange shape from the end portion of the eccentric shaft 7 on the input side of the rotation axis Ax1 . Here, the bush 70 is located on the input side of the rotation axis Ax1 as viewed from the first bearing 91 which is an inner bearing member. Accordingly, the first bearing 91 as an inner bearing member is located at a position sandwiched between the eccentric portion 72 and the bush 70 in a direction parallel to the rotation axis Ax1 . Therefore, the bush 70 functions as a "pressor" of the first bearing 91, and restricts movement of the inner bearing member (first bearing 91) in a direction parallel to the rotation axis Ax1. In short, the gear unit 1A of the present embodiment includes an inner bearing member (first bearing 91 ) that holds the input shaft (eccentric shaft 7 ) rotatably (indirectly) relative to the inner ring 61 . The bush 70 restricts movement of the inner bearing member (first bearing 91 ) to one side in a direction parallel to the rotation axis Ax1 .

In addition, in this embodiment, the input shaft (eccentric shaft 7 ) and the bush 70 have a through hole 73 penetrating along the rotation axis Ax1. That is, the through hole 73 penetrates along the rotation axis Ax1 from the shaft center portion 71 of the eccentric shaft 7 to the bush 70 . Here, the fixing structure 701 for fixing the mating member is provided on the bush 70. Therefore, if the outer diameter of the eccentric shaft 7 is the same, it is easier to secure a smaller diameter of the through hole 73 than the case without the bush 70. big. That is, since there is no need to provide a fixing structure on the eccentric shaft 7 itself, it is easy to reduce the thickness of (the axial center portion 71 of) the eccentric shaft 7 , and as a result, it is easy to increase the size of the through hole 73 .

In this embodiment, as an example, the fixing structure 701 is constituted by a screw hole. That is, by screwing the mating member with respect to the threaded hole as the fixing structure 701 , it is possible to fix the mating member with respect to the bush 70 . Here, the fixing structure 701 (threaded hole) is provided on the end face of the bush 70 facing the input side of the rotation axis Ax1. A plurality of (here, six) screw holes are provided as the fixing structure 701 (see FIG. 13 ), and a target member can be fixed with a plurality of screws. When fixing the mating member using this fixing structure 701 , the mating member is fixed on the input side of the rotation axis Ax1 with respect to the bush 70 . That is, the fixing structure 701 is configured to be able to fix the mating member on one side in a direction parallel to the rotation axis Ax1 with respect to the bush 70 .

In addition, in this embodiment, at least a part of the fixing structure 701 is located at the same position as the input shaft in a direction parallel to the rotation axis Ax1. That is, as shown in FIG. 15 , at least a part of the fixing structure 701 for fixing the matching component is located at a position overlapping with the input shaft (eccentric shaft 7 ) in a direction parallel to the rotation axis Ax1 . As a result, although the fixing structure 701 can be made larger, the size increase of the gear device 1A in the direction parallel to the rotation axis Ax1 can be suppressed.

In addition, in the present embodiment, the passage Sp1 for the inner pin is provided, and the passage Sp1 for the inner pin allows the inner pin 4 to be detached even in a state where the bush 70 is coupled to the eccentric shaft 7 . That is, the gear unit 1A includes a path Sp1 for inner pins that is located on at least one side in a direction parallel to the rotation axis Ax1 with respect to the plurality of inner pins 4 , where the input shaft (eccentric shaft 7) and the bushing are combined. In the state of the sleeve 70, the plurality of inner pins 4 can be removed respectively. Accordingly, in the gear device 1A, even after the bush 70 is coupled to the input shaft (eccentric shaft 7), the plurality of inner pins 4 can be removed respectively.

Next, a method of replacing the inner pin 4 and the rolling elements 402 of the rolling

bearings

41 and 42 in the gear device 1A according to this embodiment will be described with reference to FIGS. 25 and 26 . Here, as an example, a case where an operator replaces the inner pin 4 and the rolling

bearings

41 and 42 for the purpose of adjusting the performance (backlash, input torque, etc.) of the gear device 1A in the manufacturing process of the gear device 1A will be described. .

When replacing any one of the inner pin 4 and the rolling element 402, the operator will remove the mounting screw 160, remove the

cover body

163, 164 and the

oil seal

14, 15 from the planet carrier flange 18 and the output flange 19 (see Figure 15 ). By detaching the

lids

163 and 164, the internal pin path Sp1 is exposed.

When replacing the inner pin 4 , as shown in FIG. 25 , the operator presses a new inner pin 4A into the carrier flange 18 through the inner pin path Sp1 on the input side of the rotation axis Ax1 , for example. At this time, the existing inner pin 4 pushed by the new inner pin 4A is pushed out toward the output side of the rotation axis Ax1. Then, the existing inner pin 4 is removed while the new inner pin 4A is fully inserted. In this method, since at least one of the new inner pin 4A and the existing inner pin 4 is always inserted into each rolling

bearing

41, 42, the plurality of rolling elements 402 of the rolling

bearing

41, 42 are prevented from coming off by the

inner pin

4, 4A.

Furthermore, in the method described above, since the inner pins 4 can be replaced one by one, the gear unit 1A can be driven experimentally to check the performance (backlash, input torque, etc.) every time one inner pin 4 is replaced. Thereby, for example, there are advantages in that it is easy to identify the defective inner pin 4 and it is easy to adjust the performance of the gear unit 1A to a desired performance.

In addition, when replacing the rolling elements 402 , as shown in FIG. 26 , the operator pulls out the existing rolling elements 402 from the internal pin path Sp1 on the output side of the rotation axis Ax1 , for example. At this time, as a mechanism for pulling out the rolling elements 402 , as an example, a jig such as a magnet is suitably used. Then, the operator inserts a new rolling element 402 from the inner pin path Sp1 on the output side of the rotation axis Ax1.

Furthermore, in the method described above, since the rolling elements 402 can be replaced one by one, the gear unit 1A can be driven experimentally to check the performance (backlash, input torque, etc.) every time one rolling element 402 is replaced. Thereby, for example, there are advantages in that it is easy to identify the rolling elements 402 having problems, and it is easy to adjust the performance of the gear unit 1A to a desired performance.

When replacing any one of the inner pin 4 and the rolling element 402 , the operator installs the

cover bodies

163 , 164 and the oil seals 14 , 15 on the planetary carrier flange 18 and the output flange 19 after the replacement is completed. By attaching the

caps

163 and 164, the internal pin path Sp1 is blocked.

However, the method illustrated in FIG. 25 is only an example, and the operator may press a new inner pin 4A into the output flange 19 from the inner pin path Sp1 on the output side of the rotation axis Ax1 , for example. Furthermore, when replacing the inner pin 4 , the operator may first remove the inner pin 4 and then replace it with a new inner pin 4A in the same manner as the rolling element 402 . In addition, the inner pin 4 and the rolling element 402 may be replaced at the same time.

In addition, the replacement work of the inner pin 4 and the rolling

bearings

41 and 42 is not limited to the manufacturing process of the gear device 1A, and may be performed, for example, during maintenance work of the gear device 1A during use. That is, the maintenance method of the gear unit 1A according to the present embodiment includes the step of: in the state where the bearing member 6A, the internal gear 2 and the planetary gear 3 are combined, the plurality of internal pins 4 are rotated from the direction parallel to the rotation axis Ax1. Replace at least one of the plurality of inner pins 4 on at least one side. In addition, the manufacturing method of the gear unit 1A according to this embodiment includes a step of inserting a plurality of inner pins 4 from at least one side in a direction parallel to the rotation axis Ax1 in a state where the bearing member 6A, the inner gear 2, and the planetary gear 3 are combined. .

As shown in FIG. 27 , the gear device 1A of this embodiment constitutes a robot joint device 200 together with a first member 201 and a second member 202 . In other words, the robot joint device 200 of this embodiment includes the gear device 1A, the first member 201 and the second member 202 . The first member 201 is fixed to the outer ring 62 . The second member 202 is fixed to the inner ring 61 . FIG. 27 is a schematic cross-sectional view of the robot joint device 200 .

In this embodiment, as an example, the first member 201 is indirectly fixed to the outer ring 62 of the bearing member 6A by being fixed to a plurality of installation holes 111 formed in the housing 10 . The second part 202 is indirectly fixed relative to the inner ring 61 of the bearing part 6A by being fixed relative to the planet carrier flange 18 .

The joint device 200 for a robot configured in this way functions as a joint device when the first member 201 and the second member 202 relatively rotate about the rotation axis Ax1. Here, by driving the eccentric shaft 7 of the gear unit 1A by the first motor 203 as the drive source 101 (see FIG. 1 ), the first member 201 and the second member 202 are relatively rotated. At this time, the rotation (input rotation) generated by the drive source 101 is decelerated at a high reduction ratio in the gear unit 1A, and the first member 201 or the second member 202 is driven with a high torque. That is, the first member 201 and the second member 202 connected by the gear device 1A can perform flexion and extension around the rotation axis Ax1.

More specifically, the first pulley P1 is fixed to the output shaft of the first motor 203 . The 2nd pulley P2 is connected to the 1st pulley P1 via the timing belt T1. Here, the second pulley P2 is fixed to the fixing structure 701 of the bush 70 as a matching component. That is, when the first motor 203 is driven, its rotation is transmitted to the eccentric shaft 7 as an input shaft through the first pulley P1 , the timing belt T1 and the second pulley P2 .

In addition, the robot joint device 200 further includes a second motor 204 . The third pulley P3 is fixed to the output shaft of the second motor 204 . The fourth pulley P4 is connected to the third pulley P3 via the timing belt T2. Here, the fourth pulley P4 is fixed to the shaft 205 . The shaft 205 passes through the bush 70 and the eccentric shaft 7 through the through hole 73 . A fifth pulley P5 is fixed to an end portion of the shaft 205 on the opposite side to the fourth pulley P4. Thus, when the second motor 204 is driven, its rotation is transmitted to the fifth pulley P5 via the third pulley P3 , the timing belt T2 , the fourth pulley P4 , and the shaft 205 .

The robot joint device 200 is used for a robot such as a horizontal articulated robot (SCARA type robot), for example. Furthermore, the robot joint device 200 is not limited to the horizontal articulated robot, and may be used for industrial robots or non-industrial robots other than the horizontal articulated robot, for example. In addition, the gear device 1A of the present embodiment is not limited to the joint device 200 for a robot, and may be used, for example, as a wheel device such as an in-wheel motor for vehicles such as an automated guided vehicle (AGV: Automated Guided Vehicle).

The first embodiment is only one of various implementations of the embodiments of the present disclosure. The first embodiment may be variously modified in terms of design and the like as long as the objects of the embodiments of the present disclosure can be achieved. In addition, the drawings referred to in the embodiments of the present disclosure are all schematic diagrams, and the ratios of the sizes and thicknesses of the constituent elements in the drawings do not necessarily reflect the actual size ratios. Modified examples of the first embodiment are listed below. Modifications described below can be applied in combination as appropriate.

In the first embodiment, the gear unit 1A in which the planetary gears 3 are two types is illustrated, but the gear unit 1A may include three or more planetary gears 3 . For example, when the gear unit 1A includes three planetary gears 3 , it is preferable that the three planetary gears 3 are arranged around the rotation axis Ax1 with a phase difference of 120 degrees. In addition, the gear unit 1A may include only one planetary gear 3 . Alternatively, when the gear unit 1A includes three planetary gears 3, two of the three planetary gears 3 are in the same phase, and the remaining one planetary gear 3 is arranged around the rotation axis Ax1 with a phase difference of 180 degrees. also may.

In addition, the internal pin path Sp1 has only to be located on at least one side in the direction parallel to the rotation axis Ax1 with respect to the plurality of internal pins 4 , and does not have to be located on both sides. In addition, the

covers

163 and 164 are not essential and can be omitted as appropriate. In addition, the

covers

163 , 164 do not need to collectively cover the plurality of inner pin paths Sp1 corresponding to the plurality of inner pins 4 at the first position, and the

covers

163 , 164 may be provided separately for each inner pin 4 . In addition, the internal pin path Sp1 does not necessarily have to communicate with the lubricant holding space 17 , and the internal pin path Sp1 may be separated from the lubricant holding space 17 .

In addition, the bushing 70 does not necessarily have the insertion port 702, and the insertion port 702 may be appropriately omitted. Furthermore, the bush 70 is not necessarily bonded to the input shaft (eccentric shaft 7 ) by bonding, and may be bonded only by press fitting, for example. In addition, the bushing 70 restricts the movement of the inner bearing member (first bearing 91 ) to one side in a direction parallel to the rotation axis Ax1 , and is not an essential structure. Also, the input shaft (eccentric shaft 7 ) and the through hole 73 of the bush 70 are not essential. In addition, it is not essential that at least a part of the fixing structure 701 is located at the same position as the input shaft in the direction parallel to the rotation axis Ax1.

In addition, the plurality of sets of rolling

bearings

41 and 42 may not be arranged at equal intervals in the circumferential direction around the rotation axis Ax1 when viewed in a direction parallel to the rotation axis Ax1. Furthermore, the center of the virtual circle VC1 passing through the centers of the plurality of sets of rolling

bearings

41, 42 may not coincide with the rotation axis Ax1 when viewed from a direction parallel to the rotation axis Ax1.

In addition, the number of inner pins 4 , the number of pins 23 (the number of teeth of the inner teeth 21 ), the number of teeth of the outer teeth 31 and the like described in the first embodiment are merely examples and can be changed as appropriate.

In addition, the bearing member 6A has the same basic structure and may be a cross roller bearing or a deep groove ball bearing or the like. However, it is preferable that the bearing member 6A is capable of receiving a radial load, a thrust direction (direction along the rotation axis Ax1 ), and a bending force (bending moment load) with respect to the rotation axis Ax1 , such as a four-point contact ball bearing. any of the

In addition, the eccentric body bearing 5 is not limited to a roller bearing, For example, a deep groove ball bearing, an angular contact ball bearing, etc. may be sufficient.

In addition, the material of each component of the gear device 1A is not limited to metal, and may be resin such as engineering plastic, for example.

In addition, the gear unit 1A is not limited to the inner ring 61 (carrier flange 18 and output flange 19) as long as it can take out the relative rotation between the inner ring 61 and the outer ring 62 of the bearing member 6 as an output. A structure in which the rotational force is taken out as an output. For example, the rotational force of the outer ring 62 (housing 10 ) that rotates relative to the inner ring 61 may be taken out as an output.

In addition, the lubricant is not limited to a liquid substance such as lubricating oil (oil), but may be a gel-like substance such as grease.

In addition, the gear unit 1A may include inner rollers. That is, in the gear device 1A, the plurality of inner pins 4 do not have to be in direct contact with the inner peripheral surface 321 of the inner pin hole 32 , and inner rollers may be interposed between each of the plurality of inner pins 4 and the inner pin hole 32 . In this case, the inner roller is attached to the inner pin 4 so as to be rotatable around the inner pin 4 .

In addition, the support ring 8A is not essential in the gear unit 1A, and the support ring 8A may be appropriately omitted, or the support body 8 described in the basic structure may be used instead of the support ring 8A.

In addition, the gear unit 1A only needs to employ at least one of the design for the support structure 40 (rolling bearings 41, 42) for the inner pin 4, the design for improving the lubrication state of the inner pin 4, the design for the detachable inner pin 4, and the design for the bush 70. One will suffice, not all of them are required. That is to say, the gear unit 1A, for example, does not need to adopt the detachable design of the inner pin 4 and the design of the bush 70.

Furthermore, since the gear unit 1A only needs to adopt a design for improving the lubrication state of the inner pin 4 , other configurations can be appropriately omitted or changed from the basic configuration. For example, the plurality of inner pins 4 may not be arranged at the same position as the bearing member 6A in the axial direction of the bearing member 6A.

The input shaft coupled to the bush 70 is not limited to the structure integrally having the shaft center portion 71 and the eccentric portion 72 as the eccentric shaft 7 as long as the planetary gear 3 swings eccentrically during rotation. For example, the input shaft combined with the bush 70 may be the shaft center portion 71 formed separately from the eccentric portion 72 , and in this case, the eccentric portion is attached to the input shaft (the shaft center portion 71 ) combined with the bush 70 72.

In addition, the positioning structure for positioning the

covers

163 , 164 and the inner ring 61 relative to each other is not limited to a structure that uniquely determines the relative positions of the

covers

163 , 164 and the inner ring 61 in the rotation direction centering on the rotation axis Ax1 . The positioning structure can also position the

cover bodies

163 , 164 in a rotationally symmetrical manner with respect to the inner ring 61 of the bearing member 6A, for example, with the rotational axis Ax1 being the axis of symmetry. Furthermore, the positioning structure is not limited to the convex portion 167 and the

concave portion

184 , 194 , and can also be realized by, for example, the fitting tolerance of the

cover body

163 , 164 with respect to the carrier flange 18 and the output flange 19 . In addition, the positioning structure is not an essential structure, and can be appropriately omitted.

In addition, the fixing structure 701 provided on the bush 70 is not limited to a threaded hole, and may be a stud bolt or an adhesive surface, for example.

In addition, between the

covers

163 and 164 and the carrier flange 18 and the output flange 19 may be sealed by, for example, an O(O) ring or the like. Thereby, the airtightness of the lubricant holding space 17 can be improved.

In addition, the concave portion 174 only needs to be formed on at least one of the

cover bodies

163, 164 and the inner pin 4, and may be formed on the opposing surface of the

cover bodies

163, 164 facing the inner pin 4, or may be formed on the

cover body

163, 164 and domestic 4 both.

In addition, the circulation path 170 is not necessarily configured to circulate the lubricant between the first region R1 and the third region R3 and to circulate the lubricant between the second region R2 and the fourth region R4. That is, as shown in FIG. 28 , unlike the gear device 1A of the first embodiment, the circulation path 170 may be cut off between the first region R1 and the third region R3 and may be configured to be separated between the second region R2 and the third region R3. The gear unit 1B in which the circulation path 170 between the fourth regions R4 is also cut off. In the gear device 1B of the modified example, the circulation path 170 individually circulates the lubricant through the first region R1 , the second region R2 , the third region R3 , and the fourth region R4 . According to this configuration, since the path length of the circulation path 170 through which the lubricant circulates can be kept short, the lubricant can be efficiently circulated.

(second embodiment)

As shown in FIG. 29 , the difference between the

gear devices

1C and 1D of the present embodiment and the gear device 1A of the first embodiment is that the circulation path 170 allows lubricant to pass through all the first region R1 , the second region R2 , and the third region. R3 and the fourth region R4 circulate. Hereinafter, the same reference numerals are assigned to the same configurations as those of the first embodiment, and description thereof will be appropriately omitted.

That is, in the gear unit 1A of the first embodiment, since the circulation path 170 is cut off between the first region R1 and the second region R2, and the circulation path 170 is cut off between the third region R2 and the fourth region R4 Since it is also cut off, it is not a structure in which the lubricant circulates through all of the first region R1, the second region R2, the third region R3, and the fourth region R4. In contrast, in this embodiment, the lubricant passes through all of the first region R1, second region R1, second The region R2, the third region R3, and the fourth region R4 circulate.

In FIG. 29 , two

gear units

1C and 1D according to the present embodiment are shown. In the gear device 1C on the left side of FIG. 29 , the circulation path 170 circulates the lubricant sequentially through the first region R1 , the second region R2 , the fourth region R4 , and the third region R3 . That is, on the cross section shown in FIG. 29, the lubricant moves from the first region R1 to the second region R2, from the second region R2 to the fourth region R4, and from the fourth region R4 to the third region R3. , moving from the third region R3 to the first region R1, thereby circulating clockwise through the four regions from the first region R1 to the fourth region R4. According to this structure, since the lubricant circulates throughout the gear unit 1C, it is expected to further improve the lubrication state of the inner pin 4 .

In the gear device 1D on the right side of FIG. 29 , the circulation path 170 circulates the lubricant sequentially through the first region R1 , the fourth region R4 , the second region R2 , and the third region R3 . That is, on the cross section shown in FIG. 29, the lubricant moves from the first region R1 to the fourth region R4, from the fourth region R4 to the second region R2, and from the second region R2 to the third region R3. , moving from the third region R3 to the first region R1, thereby circulating in the four regions from the first region R1 to the fourth region R4. According to this structure, since the lubricant circulates throughout the gear unit 1C, it is expected to further improve the lubrication state of the inner pin 4 .

The configuration of the second embodiment can be used in combination with the various configurations (including modified examples) described in the first embodiment as appropriate.

(Summarize)

As described above, the internal meshing

planetary gear unit

1, 1A-1D of the first embodiment includes bearing

members

6, 6A, an internal gear 2, a planetary gear 3, a plurality of inner pins 4, a plurality of sets of rolling

bearings

41, 42, and a circulation path 170. . The bearing

members

6 and 6A have an outer ring 62 and an inner ring 61 arranged inside the outer ring 62 , and the inner ring 61 is supported so as to be relatively rotatable with respect to the outer ring 62 around the rotation axis Ax1 . The internal gear 2 has internal teeth 21 and is fixed on the outer ring 62 . The planet gears 3 have external teeth 31 which partially mesh with the internal teeth 21 . The plurality of inner pins 4 relatively rotate with respect to the inner gear 2 while revolving in the inner pin holes 32 while being respectively inserted into the plurality of inner pin holes 32 formed in the planetary gear 3 . A plurality of sets of rolling

bearings

41 , 42 respectively hold a plurality of inner pins 4 on both sides of the planetary gear 3 in a direction parallel to the rotation axis Ax1 . The circulation path 170 includes the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 and the raceways 404 of the rolling elements 402 in the rolling

bearings

41 and 42 . In the internal meshing

planetary gear unit

1 , 1A-1D, the lubricant is circulated through the circulation path 170 .

According to this aspect, since the lubricant circulates at least through the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 and the raceway 404 of the rolling element 402, the lubrication state of the inner pin 4 is improved. That is, by actively circulating the lubricant, it is less likely that the periphery of the inner pin 4 will be insufficient or exhausted of the "lubricant depletion", and more than a certain amount of lubricant will always be supplied. Furthermore, by circulating the lubricant through the circulation path 170, the lubricant can be replaced at any time, thereby suppressing deterioration of the lubricant, compared to a structure in which the lubricant stagnates at a predetermined position. As a result, there is an advantage that the loss generated when the inner pin 4 rotates can be easily reduced.

In the internal meshing

planetary gear unit

1, 1A-1D of the second form, based on the first form, the lubricant is pushed away from the planetary gear 3 in a direction parallel to the rotation axis Ax1 due to the contraction of the gap. .

According to this aspect, the lubricant is pushed out by the pump function, and the lubricant circulates through the circulation path 170 easily.

In the internal meshing

planetary gear unit

1, 1A-1D of the third aspect, the circulation path 170 circulates the lubricant mainly in one direction in addition to the first or second aspect.

According to this aspect, the flow of the lubricant in the circulation path 170 becomes smooth, and stagnation of the lubricant is less likely to occur, so that the lubrication state of the inner pin 4 can be further improved.

In the internal meshing

planetary gear units

1 and 1A-1D of the fourth aspect, in addition to the third aspect, a direction restricting portion 173 for restricting the flow direction of the lubricant is provided on at least a part of the inner peripheral surface of the circulation path 170 .

According to this form, the flow of the lubricant in the circulation path 170 becomes smooth, and stagnation of the lubricant is less likely to occur, so that the lubrication state of the inner pin 4 can be further improved.

In the internal meshing

planetary gear device

1 , 1A-1D of the fifth aspect, in any one of the first to fourth aspects, the circulation path 170 communicates between the plurality of inner pins 4 .

According to this aspect, the lubricant can be circulated in a wider range, and the lubrication state of the inner pin 4 can be further improved.

The internal meshing

planetary gear unit

1, 1A-1D of the sixth aspect is any one of the first to fifth aspects, and further includes an internal pin path Sp1. The inner pin path Sp1 is located on at least one side in the direction parallel to the rotation axis Ax1 with respect to the plurality of inner pins 4, and a plurality of inner pins 4 can be respectively detached in a state where the bearing

members

6, 6A, the inner gear 2, and the planetary gear 3 are combined. Domestic sales 4.

According to this aspect, at least the inner pin 4 can be replaced or the like without disassembling the bearing

members

6 and 6A, the inner gear 2 and the planetary gear 3 . Therefore, for example, when the diameter of the inner pin 4 is smaller than the design value, by replacing the inner pin 4 with a larger diameter, at least the toothing caused by the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 can be reduced or eliminated. gap, it is easy to suppress the angle transmission error to be small. As a result, it is possible to provide the internal meshing

planetary gear units

1 , 1A- 1D in which angular transmission errors are easily suppressed to be small.

In the internal meshing

planetary gear device

1, 1A-1D of the seventh aspect, in any one of the first to sixth aspects, the cross section including the rotation axis Ax1 is divided into one side with respect to the rotation axis Ax1 The first block B1 and become the second block B2 on the other side. The first block B1 is divided into a first region R1 on one side with respect to the planetary gear and a second region R2 on the other side, and the second block B2 is divided into a third region on one side with respect to the planetary gear. R3 and become the fourth region R4 on the other side. The circulation path 170 is provided in all of the first region R1, the second region R2, the third region R3, and the fourth region R4.

According to this aspect, the circulation path 170 extends over the entire internal meshing

planetary gear device

1, 1A-1D, and the lubrication state of the inner pin 4 can be improved in the entire internal meshing

planetary gear device

1, 1A-1D.

In the eighth aspect of the internal meshing

planetary gear unit

1, 1A-1D, on the basis of the seventh aspect, the circulation path 170 makes the lubricant flow in the first region R1, the second region R2, the third region R3 and the fourth region respectively. Region R4 circulates alone.

According to this aspect, since the path length of the circulation path 170 through which the lubricant circulates can be kept short, the lubricant can be efficiently circulated.

In the internal meshing

planetary gear unit

1, 1A-1D of the ninth aspect, in addition to the seventh aspect, the circulation path 170 circulates the lubricant between the first region R1 and the third region R3, and the lubricant circulates between the first region R1 and the third region R3. Cycle between the second region R2 and the fourth region R4.

According to this form, the lubricant circulates between the two regions sandwiching the rotation axis Ax1 on the cross section including the rotation axis Ax1 , so that it is expected to further improve the lubrication state of the inner pin 4 .

In the tenth aspect of the internal meshing

planetary gear unit

1, 1A-1D, in addition to the seventh aspect, the circulation path 170 allows the lubricant to pass through all the first region R1, the second region R2, the third region R3 and the fourth region R1. Region R4 and cycle.

According to this mode, since the lubricant circulates throughout the internal meshing

planetary gear unit

1, 1A-1D, it is expected that the lubrication state of the inner pin 4 will be further improved.

In the eleventh aspect of the internal meshing

planetary gear unit

1, 1A-1D, in addition to the tenth aspect, the circulation path 170 makes the lubricant flow through the first region R1, the second region R2, the fourth region R4, the Three-region R3 loop.

According to this manner, since the lubricant circulates throughout the internal meshing

planetary gear unit

1, 1A-1D, it is expected to further improve the lubrication state of the inner pin 4.

In the internal meshing

planetary gear unit

1, 1A-1D of the twelfth aspect, in addition to the tenth aspect, the circulation path 170 makes the lubricant flow through the first region R1, the fourth region R4, the second region R2, the Loop in three regions R3.

planetary gear unit

The internal meshing

planetary gear unit

1, 1A-1D of the thirteenth aspect is any one of the first to twelfth aspects, and further includes a plurality of inner pins 4 positioned in a direction parallel to the rotation axis Ax1. At least one of the

lids

163 , 164 has grooves 171 formed in the

lids

163 , 164 , and the grooves 171 form a part of the circulation path 170 .

According to this aspect, the circulation path 170 can be provided with a relatively simple structure.

In the internal meshing

planetary gear unit

1, 1A-1D of the fourteenth aspect, in addition to the thirteenth aspect, at least one of the

cover bodies

163, 164 and the inner pin 4 is formed to communicate with and maintain the circulation path 170. Recess 174 for lubricant.

According to this aspect, when the amount of lubricant in the circulation path 170 is reduced, the lubricant held in the concave portion 174 can be supplied to the circulation path 170 , and the occurrence of lubricant depletion can be easily suppressed.

The robot joint device 200 of the fifteenth aspect includes the internal meshing

planetary gear device

1 , 1A-1D of any one of the first to fourteenth aspects, a first member 201 fixed to the outer ring 62 , and a first member 201 fixed to the inner ring 62 . 61 of the second part 202 .

According to this aspect, it is possible to provide the joint device 200 for a robot that can easily reduce the loss that occurs when the inner pin 4 rotates.

The structures of the second to fourteenth aspects are not essential to the internal meshing

planetary gear units

1, 1A-1D, and may be appropriately omitted.

Explanation of reference signs:

1, 1A, 1B, 1C, 1D internal meshing planetary gear device

2 internal gears

3 planetary gears

4 domestic sales

6. 6A bearing parts

21 internal teeth

31 external teeth

32 inner pin hole

41, 42 Rolling bearings

61 inner ring

62 outer ring

163, 164 cover body

170 Loop Road

171 Groove

173 Direction Restriction Department

174 recesses

200 robot joint device

201 first part

202 second part

321 (inner pin hole) inner peripheral surface

402 rolling body

404 raceway

Ax1 rotation axis

B1 first block

B2 second block

R1 first area

R2 second area

R3 third area

R4 fourth area

Sp1 domestic sales route

Industrial Applicability

According to the embodiments of the present disclosure, it is possible to provide an internal meshing planetary gear device and a joint device for a robot that easily reduce losses generated when the inner pin rotates.

Claims

An internal meshing planetary gear device, comprising:

a bearing component having an outer ring and an inner ring arranged inside the outer ring, the inner ring being supported relative to the outer ring so as to be relatively rotatable about a rotation axis;

an internal gear having internal teeth and fixed to the outer ring;

a planetary gear having external teeth partially meshing with said internal teeth;

The plurality of inner pins are inserted into the plurality of inner pin holes formed in the planetary gear, and rotate relative to the inner gear while revolving in the inner pin hole;

a plurality of sets of rolling bearings respectively holding the plurality of inner pins at both sides in a direction parallel to the rotation shaft with respect to the planetary gear; and

a circulation path, including the gap between the inner peripheral surface of the inner pin hole and the inner pin and the raceways of the rolling elements in the rolling bearing,

In the internal meshing planetary gear device, lubricant is circulated through the circulation passage.
The internal meshing planetary gear device according to claim 1, wherein,

The lubricant is pushed out in a direction parallel to the rotation axis in a direction away from the planetary gear due to the contraction of the gap.
The internal meshing planetary gear device according to claim 1 or 2, wherein,

The circulation path circulates the lubricant mainly in one direction.
The internal meshing planetary gear device according to claim 3, wherein,

A direction restricting portion for restricting a flow direction of the lubricant is provided on at least a part of an inner peripheral surface of the circulation path.
The internal meshing planetary gear device according to any one of claims 1 to 4, wherein,

The circulation path communicates among the plurality of inner pins.
The internal meshing planetary gear device according to any one of claims 1 to 5, wherein,

The internal meshing planetary gear device further includes a path for internal pins located on at least one side in a direction parallel to the rotation shaft with respect to the plurality of internal pins, between the bearing member, the internal gear and In the state where the planetary gears are combined, the plurality of inner pins can be removed respectively.
The internal meshing planetary gear device according to any one of claims 1 to 6, wherein:

A section including the rotation axis is divided into a first block on one side with respect to the rotation axis and a second block on the other side, and the first block is divided into The planetary gear becomes a first area on one side and a second area on the other side, and the second block is divided into a third area on the one side and a third area on the other side with respect to the planetary gear. side of the fourth area,

The circulation paths are provided in all of the first area, the second area, the third area, and the fourth area.
The internal meshing planetary gear device according to claim 7, wherein:

The circulation path individually circulates the lubricant in the first area, the second area, the third area, and the fourth area.
The internal meshing planetary gear device according to claim 7, wherein:

The circulation path circulates the lubricant between the first area and the third area, and circulates the lubricant between the second area and the fourth area.
The internal meshing planetary gear device according to claim 7, wherein:

The circulation path circulates the lubricant through all of the first region, the second region, the third region, and the fourth region.
The internal meshing planetary gear device according to claim 10, wherein:

The circulation path circulates the lubricant sequentially through the first area, the second area, the fourth area, and the third area.
The internal meshing planetary gear device according to claim 10, wherein:

The circulation path circulates the lubricant sequentially through the first area, the fourth area, the second area, and the third area.
The internal meshing planetary gear device according to any one of claims 1 to 12, wherein,

The internal meshing planetary gear device further includes a cover located on at least one side in a direction parallel to the rotation shaft with respect to the plurality of inner pins,

A groove is formed in the cover, and the groove forms a part of the circulation path.
The internal meshing planetary gear device according to claim 13, wherein:

At least one of the cover body and the inner pin is formed with a concave portion that communicates with the circulation path and holds the lubricant.
A joint device for a robot, including:

The internal meshing planetary gear device according to any one of claims 1 to 14;

a first component fixed to the outer race; and

The second component is fixed to the inner ring.