WO2022227558A1

WO2022227558A1 - Internally meshing planetary gear device, joint device for robot, maintenance method, and manufacturing method for internally meshing planetary gear device

Info

Publication number: WO2022227558A1
Application number: PCT/CN2021/134342
Authority: WO
Inventors: 林文捷; 王刚; 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: 2021-04-27
Filing date: 2021-11-30
Publication date: 2022-11-03
Also published as: JP2022169213A; CN117062997A; JP7490611B2

Abstract

An internally meshing planetary gear device (1, 1A), a joint device (200) for a robot, a maintenance method, and a manufacturing method for the internally meshing planetary gear device (1, 1A). The internally meshing planetary gear device (1, 1A) comprises a bearing member (6, 6A), an internally toothed gear (2), a planetary gear (3), a plurality of inner pins (4), and a path (Sp1) for inner pins. The plurality of inner pins (4) are configured on an inner side of an inner ring (61) as viewed from a direction parallel to a rotation axis (Ax1), and when in a state of being respectively inserted into a plurality of inner pin holes (32) formed in the planetary gear (3), same revolve in the inner pin holes (32) and also rotate relatively with respect to the internally toothed gear (2). The path (Sp1) for inner pins is located, with respect to the plurality of inner pins (4), on at least one side in the direction parallel to the rotation axis (Ax1), and each inner pin (4) of the plurality of inner pins (4) can be removed under a state in which the bearing member (6, 6A), the internally toothed gear (2) and the planetary gear (3) are combined.

Description

Internal meshing planetary gear device, joint device for robot, maintenance method, and manufacturing method of internal meshing planetary gear device

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on the Japanese Patent Application No. 2021-075095 and the filing date is April 27, 2021, and claims the priority of the Japanese Patent Application, the entire contents of which are hereby incorporated into the present application as refer to.

technical field

The embodiments of the present disclosure generally relate to an internal meshing planetary gear device, a joint device for a robot, a maintenance method, and a manufacturing method of the internal meshing planetary gear device, and more specifically, to an internal gear having internal teeth arranged inside an internal gear having internal teeth. An internal meshing planetary gear device of an externally toothed planetary gear, a joint device for a robot, a maintenance method, and a manufacturing method of the internal meshing planetary gear device.

Background technique

As a related art, a so-called eccentric oscillating type gear device in which a planetary gear is internally meshed with an internal gear while eccentrically oscillating is known (for example, see Patent Document 1). In the gear device of the related art, the eccentric body is integrally formed with the input shaft, and the planetary gear is mounted on the eccentric body via the eccentric body bearing. External teeth such as circular arc teeth are formed on the outer circumference of the planetary gear.

The internally toothed gear is configured by rotatably fitting a plurality of pins (roller pins) that form internal teeth one by one to the inner peripheral surface of a gear main body (internally toothed gear main body) that also serves as a housing. In the planetary gear, a plurality of inner pin holes (inner roller holes) are formed at appropriate intervals in the circumferential direction, and inner pins and inner rollers are inserted into the inner pin holes. The inner pin is connected to the bracket at one end side in the axial direction, and the bracket is rotatably supported by the housing via a crossed roller bearing. This gear device can be used as a gear device in which the rotation corresponding to the rotation component of the planetary gear when the internal gear is fixed is taken out from the carrier.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2003-74646

SUMMARY OF THE INVENTION

The technical problem to be solved by the invention

In the structure of the above-mentioned related art, a gap is ensured between the inner peripheral surface of the inner pin hole and the inner roller in a state where the gear device is assembled in consideration of assembly tolerance and the like. Further, a gap is also ensured between the inner peripheral surface of the inner roller and the inner pin so that the inner roller can rotate with respect to the inner pin. These gaps become backlash, and, for example, in a joint device for a robot, an angle transmission error of the gear device may become a problem depending on the application of the gear device.

An object of the embodiments of the present disclosure is to provide an internal meshing planetary gear device, a robot joint device, a maintenance method, and a manufacturing method of the internal meshing planetary gear device that can easily suppress the angle transmission error to a small value.

Solutions for Technical Problems

An internal meshing planetary gear device according to one aspect of the embodiment of the present disclosure includes a bearing member, an internally toothed gear, a planetary gear, a plurality of inner pins, and a path for the inner pins. The bearing member includes an outer ring and an inner ring disposed inside the outer ring, and supports the inner ring to be rotatable relative to the outer ring about a rotation axis. The internal gear has internal teeth and is fixed to the outer ring. The planetary gear has external teeth partially meshed with the internal teeth. The plurality of inner pins are disposed on the inner side of the inner ring when viewed from a direction parallel to the rotation axis, and are inserted into the plurality of inner pin holes formed in the planetary gear while being inserted into the inner pin holes, respectively. The inner revolving side rotates relatively with respect to the inner tooth gear. The inner pin path is located on at least one side of a direction parallel to the rotation axis with respect to the plurality of inner pins, and in a state in which the bearing member, the inner gear, and the planetary gear are combined Each inner pin of the plurality of inner pins can be removed.

A joint device for a robot according to one aspect of the 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.

A maintenance method of one aspect of the embodiment of the present disclosure is used for an internal meshing planetary gear device including a bearing member, an internally toothed gear, a planetary gear, and a plurality of internal pins. The bearing member includes an outer ring and an inner ring disposed inside the outer ring, and supports the inner ring to be rotatable relative to the outer ring about a rotation axis. The internal gear has internal teeth and is fixed to the outer ring. The planetary gear has external teeth partially meshed with the internal teeth. The plurality of inner pins are disposed on the inner side of the inner ring when viewed from a direction parallel to the rotation axis, and are inserted into the plurality of inner pin holes formed in the planetary gear while being inserted into the inner pin holes, respectively. The inner revolving side rotates relatively with respect to the inner tooth gear. The maintenance method includes replacing the plurality of inner pins from at least one side in a direction parallel to the rotation axis in a state in which the bearing member, the inner gear, and the planetary gear are combined. A process of at least one of the plurality of domestic pins.

A method of manufacturing an internal meshing planetary gear device according to one aspect of the embodiment of the present disclosure is a manufacturing method of an internal meshing planetary gear device including a bearing member, an internally toothed gear, a planetary gear, and a plurality of internal pins. The bearing member includes an outer ring and an inner ring disposed inside the outer ring, and supports the inner ring to be rotatable relative to the outer ring about a rotation axis. The internal gear has internal teeth and is fixed to the outer ring. The planetary gear has external teeth partially meshed with the internal teeth. The plurality of inner pins are disposed on the inner side of the inner ring when viewed from a direction parallel to the rotation axis, and are inserted into the plurality of inner pin holes formed in the planetary gear while being inserted into the inner pin holes, respectively. The inner revolving side rotates relatively with respect to the inner tooth gear. The method of manufacturing the internal meshing planetary gear device includes inserting the bearing member, the internal gear, and the planetary gear together from at least one side in a direction parallel to the rotating shaft. Multiple domestic sales processes.

Invention effect

According to the embodiments of the present disclosure, it is possible to provide an internal meshing planetary gear device, a joint device for a robot, a maintenance method, and a manufacturing method of the internal meshing planetary gear device, which are easy to suppress to a small angle transmission error.

Description of drawings

FIG. 1 is a perspective view showing a schematic configuration of an actuator including an internal meshing planetary gear device having a basic configuration.

FIG. 2 is a schematic exploded perspective view of the above-mentioned internal meshing planetary gear device as seen from the output side of the rotating shaft.

3 is a schematic cross-sectional view of the above-mentioned internal meshing planetary gear device.

FIG. 4 is a cross-sectional view taken along line A1-A1 of FIG. 3 , showing the above-mentioned internal meshing planetary gear device.

FIG. 5A is a perspective view showing a planetary gear of the above-mentioned ring gear device as a single unit.

FIG. 5B is a front view showing the planetary gear of the above-mentioned internal meshing planetary gear device alone.

FIG. 6A is a perspective view showing the bearing member of the above-mentioned ring gear device as a single unit.

FIG. 6B is a front view showing the bearing member of the above-mentioned internal meshing planetary gear device as a single unit.

FIG. 7A is a perspective view showing the eccentric shaft of the above-mentioned ring gear device as a single unit.

FIG. 7B is a front view showing the eccentric shaft of the above-mentioned internal meshing planetary gear device alone.

FIG. 8A is a perspective view showing the support body of the above-mentioned ring gear device as a single unit.

FIG. 8B is a front view showing the support body of the above-mentioned internal meshing planetary gear unit as a single body.

FIG. 9 is an enlarged view of a region Z1 of FIG. 3 showing the above-described ring gear device.

FIG. 10 is a cross-sectional view taken along line B1-B1 of FIG. 3 , showing the above-mentioned internal meshing planetary gear device.

11 is a schematic cross-sectional view of the internal meshing planetary gear device according to the first embodiment.

FIG. 12 is a cross-sectional view taken along line B1-A1 of FIG. 13 , showing the above-mentioned internal meshing planetary gear device.

FIG. 13 is a side view of the above-described internal meshing planetary gear device as viewed from the input side of the rotary shaft.

FIG. 14 is a side view of the above-mentioned internal meshing planetary gear device as seen from the output side of the rotary shaft.

FIG. 15 is a schematic cross-sectional view showing a state in which the cover body and the oil seal are removed in the above-mentioned internal meshing planetary gear device.

16 is a side view from the input side of the rotating shaft, showing a state in which the cover body and the oil seal are removed in the above-mentioned ring gear device.

17 is a side view from the output side of the rotating shaft, showing a state in which the cover body and the oil seal are removed in the above-described ring gear device.

FIG. 18 is a cross-sectional view taken along line A1-A1 of FIG. 11 , showing the above-described ring gear device.

FIG. 19 is a cross-sectional view taken along the line B1-B1 of FIG. 11 , showing the above-mentioned internal meshing planetary gear device.

FIG. 20 is an explanatory diagram showing the arrangement of rolling bearings in the above-mentioned ring gear device.

FIG. 21 is a schematic explanatory diagram showing the replacement procedure of the inner pin in the above-mentioned ring gear device.

FIG. 22 is a schematic explanatory diagram showing the replacement procedure of the rolling elements in the above-mentioned internal meshing planetary gear device.

23 is a schematic cross-sectional view showing a joint device for a robot using the above-mentioned internal meshing planetary gear device.

Detailed ways

(basic structure)

(1) Outline

Hereinafter, the outline of the internal meshing planetary gear device 1 of the present basic structure will be described with reference to FIGS. 1 to 3 . The drawings referred to in the embodiments of the present disclosure are schematic drawings, and the respective ratios of the sizes and thicknesses of the structural elements in the drawings do not necessarily reflect the actual size ratios. For example, the tooth shape, size, and number of teeth of the inner teeth 21 and the outer teeth 31 in FIGS. 1 to 3 are only schematically shown for illustration, and the gist thereof is not limited to the shapes shown in the drawings.

The internal meshing planetary gear device 1 (hereinafter, also simply referred to as “gear device 1 ”) of the present basic structure is a gear device including an internally toothed gear 2 , a planetary gear 3 , and a plurality of inner pins 4 . In the gear device 1, the planetary gears 3 are arranged inside the annular internal gear 2, and further, the eccentric body bearing 5 is arranged inside the planetary gears 3. As shown in FIG. The eccentric body bearing 5 has an eccentric inner ring 51 and an eccentric outer ring 52, and the eccentric inner ring 51 rotates (eccentrically moves about a rotation axis Ax1 (see FIG. 3 ) offset from the center C1 (see FIG. 3 ) of the eccentric inner ring 51 ), thereby causing the planetary gear 3 to oscillate. The eccentric inner ring 51 is rotated (eccentrically moved) around the rotation axis Ax1 by, for example, the rotation of the eccentric shaft 7 inserted into the eccentric inner ring 51 . In addition, the internal meshing planetary gear device 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 is supported rotatably relative to the outer ring 62 .

The internally toothed gear 2 has internal teeth 21 and is fixed to the outer ring 62 . In particular, in this basic structure, the internally toothed gear 2 has an annular gear body 22 and a plurality of pins 23 . The plurality of pins 23 are held on the inner peripheral surface 221 of the gear body 22 in a rotatable state to constitute the internal teeth 21 . The planetary gear 3 has external teeth 31 partially meshed with the internal teeth 21 . That is, on the inner side of the internal gear 2 , the planetary gears 3 are inscribed in the internal gear 2 , and a part of the external teeth 31 and a part of the internal teeth 21 are meshed with each other. In this state, when the eccentric shaft 7 rotates, the planetary gear 3 oscillates, and the meshing position of the inner teeth 21 and the outer teeth 31 moves along the circumferential direction of the inner gear 2, and between the two gears (inner gear 2 and planetary gear 3) A relative rotation corresponding to the difference in the number of teeth of the planetary gear 3 and the internal gear 2 occurs between them. Here, when the internal gear 2 is fixed, the planetary gear 3 rotates (autorotates) in accordance with the relative rotation of the two gears. As a result, a rotational output reduced by a relatively high reduction ratio according to the difference in the number of teeth between the two gears can be obtained from the planetary gear 3 .

Such a gear device 1 is used by taking out the rotation corresponding to the rotation component of the planetary gear 3 as, for example, the rotation of the output shaft integrated with the inner ring 61 of the bearing member 6 . Accordingly, the gear device 1 functions as a gear device having a relatively 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 of the present basic structure, the planetary gears 3 and the inner ring 61 are connected by the plurality of inner pins 4 in order to transmit the rotation corresponding to the rotation component of the planetary gears 3 to the inner ring 61 of the bearing member 6 . The plurality of inner pins 4 are respectively inserted into the plurality of inner pin holes 32 formed in the planetary gear 3 , and respectively 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. In addition, the swing component of the planetary gear 3 , that is, the revolution component of the planetary gear 3 is absorbed by the loose engagement between the inner pin hole 32 of the planetary gear 3 and the inner pin 4 . In other words, the plurality of inner pins 4 move so as to revolve within the plurality of inner pin holes 32 , respectively, thereby absorbing the swing component of the planetary gear 3 . Therefore, the rotation (rotational component) of the planetary gear 3 other than the swing 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 the gear device 1 of this type, the inner pin 4 revolves in the inner pin hole 32 of the planetary gear 3, and the rotation of the planetary gear 3 is transmitted to the plurality of inner pins 4. Therefore, as a first related art, there is known a technique using a The inner pin 4 is the technology of the inner roller which can rotate the inner pin 4 as the axis. That is, in the first related art, the inner pin 4 is kept pressed into the inner ring 61 (or the bracket integrated with the inner ring 61 ), and when the inner pin 4 revolves in the inner pin hole 32 , the inner pin 4 It slides with respect to the inner peripheral surface 321 of the inner pin hole 32 . Therefore, as the first related technique, the inner roller is used in order to reduce the loss due to the frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 . However, with the structure including the inner roller as in the first related art, the inner pin hole 32 needs to have a diameter that enables the inner pin 4 with the inner roller to revolve, and it is difficult to reduce the size of the inner pin hole 32 . When it is difficult to miniaturize the inner pin hole 32 , the miniaturization of the planetary gear 3 (in particular, the reduction in diameter) is hindered, and even the miniaturization of the entire gear device 1 is hindered. The gear device 1 of the present basic structure can provide the internal meshing planetary gear device 1 which can be easily miniaturized by the following structure.

That is, as shown in FIGS. 1 to 3 , the gear device 1 of the present basic structure includes a bearing member 6 , an internally toothed gear 2 , a planetary gear 3 , and a plurality of inner pins 4 . The bearing member 6 has an outer ring 62 and an inner ring 61 arranged inside the outer ring 62 . The inner ring 61 is supported so as to be rotatable relative to the outer ring 62 . The internally toothed gear 2 has internal teeth 21 and is fixed to the outer ring 62 . The planetary gear 3 has external teeth 31 partially meshed with the internal teeth 21 . The plurality of inner pins 4 rotate relative to the internally toothed gear 2 while revolving in the inner pin holes 32 in a state of being inserted into the plurality of inner pin holes 32 formed in the planetary gear 3 , respectively. Here, each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state. Furthermore, 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 .

According to this aspect, since each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state, when the inner pins 4 revolve in the inner pin holes 32 , the inner pins 4 themselves can be rotated. 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 which is mounted on the inner pin 4 and can rotate on the inner pin 4 as an axis. Therefore, in the gear device 1 of the present basic structure, the inner rollers are not necessary, and there is an advantage that the size can be easily reduced. Furthermore, 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 , so that the size of the gear device 1 in the axial direction of the bearing member 6 can be kept small. That is to say, in the gear unit 1 of the present basic structure, the size of the gear unit 1 in the axial direction can be reduced, compared with the structure in which the bearing member 6 and the inner pin 4 are arranged in parallel (opposed) in the axial direction of the bearing member 6 . Accordingly, it is possible to contribute to further miniaturization (thinning) of the gear device 1 .

Further, if the size of the planetary gear 3 is the same as that of the first related art, compared with the first related art, for example, the number of inner pins 4 can be increased (the number of pins) to smooth the transmission of rotation, or the inner pins can be 4 Thicken to increase strength.

In addition, in the gear device 1 of this type, the inner pins 4 need to revolve in the inner pin holes 32 of the planetary gears 3 , so as a second related technique, there are a plurality of inner pins 4 only supported by the inner ring 61 (or a bracket integrated with the inner ring 61 ). ) to maintain the situation. According to the second related technique, it is difficult to improve the accuracy of the centering of the plurality of inner pins 4, and the poor centering may cause problems such as generation of 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 rotation axis of the inner pins 4 is deviated or inclined with respect to the rotation axis of the inner ring 61 due to insufficient centering accuracy of the inner pins 4, the centering will be poor, which may lead to the generation of vibration and Defects such as a drop in transfer efficiency. The gear device 1 of the present basic structure can provide the internal meshing planetary gear device 1 in which a problem caused by poor center alignment of the plurality of inner pins 4 is less likely to occur by the following structure.

That is, as shown in FIGS. 1 to 3 , the gear device 1 of the present basic structure includes an internally toothed gear 2 , a planetary gear 3 , a plurality of inner pins 4 , and a support body 8 . The internally toothed gear 2 has an annular gear body 22 and a plurality of pins 23 . The plurality of pins 23 are held on the inner peripheral surface 221 of the gear body 22 in a rotatable state to constitute the internal teeth 21 . The planetary gear 3 has external teeth 31 partially meshed with the internal teeth 21 . The plurality of inner pins 4 rotate relative to the gear body 22 while revolving in the inner pin holes 32 in a state of being inserted into the plurality of inner pin holes 32 formed in the planetary gear 3 , respectively. The support body 8 is annular and supports the plurality of inner pins 4 . 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 the relative deviation and inclination of the plurality of inner pins 4 can be suppressed. Then, the outer peripheral surface 81 of the support body 8 is in contact with the plurality of pins 23 , whereby the position of the support body 8 is regulated. In short, the centering of the support body 8 is performed by the plurality of pins 23 , and as a result, the centering of the plurality of inner pins 4 supported by the support body 8 is also performed by the plurality of pins 23 . Therefore, according to the gear device 1 of the present basic structure, it is easy to improve the accuracy of the alignment of the plurality of inner pins 4 , and there is an advantage that problems caused by poor alignment of the plurality of inner pins 4 are less likely to occur.

In addition, as shown in FIG. 1 , the gear device 1 of the present basic structure constitutes an actuator 100 together with a drive source 101 . In other words, the actuator 100 of the present basic structure includes the gear device 1 and the drive source 101 . The drive source 101 generates a drive force for swinging the planetary gear 3 . Specifically, the drive source 101 oscillates the planetary gear 3 by rotating the eccentric shaft 7 around the rotation axis Ax1.

(2) Definition

In the embodiments of the present disclosure, the term “annular” refers to a shape such as a ring (ring) that forms a space (region) enclosed on the inside at least in plan view, and is not limited to a circle that is a perfect circle in plan view The shape (annulus) may be, for example, an elliptical shape, a polygonal shape, or the like. Furthermore, for example, even a shape having a bottom such as a cup shape is included in "annular shape" as long as its peripheral wall is annular.

The "free fit" in the embodiment of the present disclosure refers to a state of being fitted with play (gap), and the inner pin hole 32 is a hole in which the inner pin 4 is loosely fitted. That is, the inner pin 4 is inserted into the inner pin hole 32 in a state in which a margin of space (gap) is secured between the inner pin 4 and the inner peripheral surface 321 of the inner pin hole 32 . In other words, the diameter of at least a 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 can move in the inner pin hole 32 in a state of being inserted into the inner pin hole 32 , that is, it can move relatively with respect to the center of the inner pin hole 32 . Thereby, the inner pin 4 can revolve in the inner pin hole 32 . However, between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4, it is not necessary to secure a gap as a cavity, and for example, a fluid such as a liquid may be filled in the gap.

The "revolution" mentioned in the embodiments of the present disclosure means that an object revolves around a rotation axis other than the central axis passing through the center (center of gravity) of the object. Orbital movement. Therefore, for example, when an object rotates around an eccentric axis parallel to a central axis passing through the center (center of gravity) of the object, the object revolves around the eccentric axis as a rotation axis. As an example, the inner pin 4 revolves in the inner pin hole 32 in a circle around a rotation axis passing through the center of 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 referred to as the “input side”, and the other side (the right side in FIG. 3 ) of the rotation axis Ax1 is referred to as the “output side”. side" situation. In the example of FIG. 3, rotation is imparted 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 merely labels given for description, and the gist thereof does not limit the positional relationship between input and output as viewed from the gear device 1 .

The "rotation axis" referred to in the embodiments of the present disclosure refers to a virtual 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 not accompanied by a substance. The eccentric inner ring 51 rotates around the rotation axis Ax1.

The "internal teeth" and "external teeth" mentioned in the embodiments of the present disclosure respectively refer to a collection (group) of a plurality of "teeth" rather than a single "teeth". That is, the internal teeth 21 of the internally toothed gear 2 are constituted by a set of a plurality of teeth arranged on the inner peripheral surface 221 of the internally toothed gear 2 (gear body 22 ). Similarly, the external teeth 31 of the planetary gears 3 are composed of a plurality of sets of teeth arranged on the outer peripheral surface of the planetary gears 3 .

(3) Composition

Hereinafter, the detailed structure of the internal meshing planetary gear device 1 of the present 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 . In FIG. 1, a drive source 101 is schematically shown. FIG. 2 is a schematic exploded perspective view of the gear device 1 viewed from the output side of the rotation shaft Ax1 . FIG. 3 is a schematic cross-sectional view of the gear device 1 . FIG. 4 is a cross-sectional view taken along the line A1-A1 in FIG. 3 . In addition, in FIG. 4, about the member other than the eccentric shaft 7, although it is also a cross section, the hatching is abbreviate|omitted. Furthermore, in FIG. 4 , illustration of the inner peripheral surface 221 of the gear body 22 is omitted. 5A and 5B are a perspective view and a front view showing the planetary gear 3 as a single unit. 6A and 6B are a perspective view and a front view showing the bearing member 6 alone. 7A and 7B are a perspective view and a front view showing the eccentric shaft 7 alone. 8A and 8B are a perspective view and a front view showing the support body 8 as a single body.

(3.1) Overall structure

As shown in FIGS. 1 to 3 , the gear device 1 of this basic structure includes an internally toothed gear 2 , a planetary gear 3 , a plurality of inner pins 4 , an eccentric body bearing 5 , a bearing member 6 , an eccentric shaft 7 , and a support body 8 . In addition, in this basic structure, the gear device 1 further includes the first bearing 91 , the second bearing 92 , and the 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 , the support body 8 , etc., which are components of the gear device 1 , are made of stainless steel, Metals such as cast iron, carbon steel for mechanical structures, chromium molybdenum steel, phosphor bronze or aluminum bronze. The metal referred to here includes a metal subjected to surface treatment such as nitriding treatment.

In addition, in the present basic structure, as an example of the gear device 1, an inscribed planetary gear reduction device using a cycloid tooth profile is exemplified. That is, the gear device 1 of the present basic structure includes the inscribed planetary gears 3 having a cycloid-like tooth profile.

In this basic structure, as an example, the gear device 1 is used in a state where the gear body 22 of the internal gear 2 is fixed to a fixing member such as the housing 10 together with the outer ring 62 of the bearing member 6 . Thereby, with the relative rotation of the internal gear 2 and the planetary gears 3, the planetary gears 3 are rotated relative to the stationary member (the case 10, etc.).

Furthermore, in the present basic structure, when the gear device 1 is used for the actuator 100 , the eccentric shaft 7 is taken out from the output shaft integrated with the inner ring 61 of the bearing member 6 by applying a rotational force as an input to the eccentric shaft 7 . Rotational force as output. That is, the gear device 1 operates with the rotation of the eccentric shaft 7 as the input rotation, and the rotation of the output shaft integrated with the inner ring 61 as the output rotation. As a result, in the gear device 1, the output rotation reduced by a relatively high reduction ratio with respect to the input rotation can be obtained.

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

Furthermore, in the gear device 1 of the present basic structure, as shown in FIG. 3 , the rotation axis Ax1 on the input side and the rotation axis Ax1 on the output side are on the same straight line. In other words, the rotation axis Ax1 on the input side and the rotation axis Ax1 on the output side are coaxial. Here, the rotation axis Ax1 on the input side is the rotation center of the eccentric shaft 7 to which the input rotation is given, and the rotation axis Ax1 on the output side is the rotation center of the inner ring 61 (and the output shaft) which generates the output rotation. That is, in the gear device 1, the output rotation reduced by a relatively high reduction ratio can be obtained coaxially with respect to the input rotation.

As shown in FIG. 4 , the internally toothed gear 2 is an annular member having internal teeth 21 . In this basic structure, the internally toothed gear 2 has at least an annular shape whose inner peripheral surface is a perfect circle in plan view. Internal teeth 21 are formed on the inner peripheral surface of the annular internal gear 2 along the circumferential direction of the internal gear 2 . All of the plurality of teeth constituting the internal teeth 21 have the same shape, and are provided at equal intervals over the entire area of the inner peripheral surface of the internally toothed gear 2 in the circumferential direction. That is, the pitch circle of the inner teeth 21 is a perfect circle in plan view. The center of the pitch circle of the internal teeth 21 is on the rotation axis Ax1. In addition, the internally toothed gear 2 has a predetermined thickness in the direction of the rotation axis Ax1. The tooth directions of the internal teeth 21 are all parallel to the rotation axis Ax1. The dimension in the tooth direction of the internal teeth 21 is slightly smaller than the thickness direction of the internal tooth gear 2 .

Here, as described above, the internally toothed gear 2 has an annular (annular) gear body 22 and a plurality of pins 23 . The plurality of pins 23 are held on the inner peripheral surface 221 of the gear body 22 in a rotatable state to constitute the internal teeth 21 . In other words, each of the plurality of pins 23 functions as a plurality of teeth constituting the inner 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 body 22 in the circumferential direction. All of the plurality of grooves have the same shape and are provided at equal intervals. The plurality of grooves are all formed in parallel to the rotation axis Ax1 over the entire length of the gear body 22 in the thickness direction. The plurality of pins 23 are assembled to the gear body 22 so as to be fitted into the plurality of grooves. Each of the plurality of pins 23 is held in a state capable of rotating in the groove. In addition, the gear body 22 (together with the outer ring 62 ) is fixed to the casing 10 . Therefore, a plurality of fixing holes 222 for fixing are formed in the gear body 22 .

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

Here, an eccentric body bearing 5 and an eccentric shaft 7 are combined with the planetary gear 3 . That is, the planetary gear 3 is formed with the opening portion 33 that is opened in a circular shape. The opening portion 33 is a hole penetrating the planetary gear 3 in the thickness direction. In plan view, the center of the opening 33 is aligned with the center of the planetary gear 3 , and the inner peripheral surface of the opening 33 (the inner peripheral surface of the planetary gear 3 ) and the pitch circle of the outer teeth 31 are concentric circles. 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 body bearing 5 (the eccentric inner ring 51 ), 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 swings around the rotation axis Ax1.

The planetary gears 3 thus constituted are arranged inside the internally toothed gears 2 . In a plan view, the planetary gear 3 is formed to be smaller than the internal gear 2 , and the planetary gear 3 can swing inside the internal gear 2 when combined with the internal gear 2 . At this time, the outer teeth 31 are formed on the outer peripheral surface of the planetary gear 3 , and the inner teeth 21 are formed on the inner peripheral surface of the inner gear 2 . Therefore, in a state where the planetary gears 3 are arranged inside the inner gear 2 , the outer teeth 31 and the inner teeth 21 face each other.

Further, the pitch circle of the outer teeth 31 is one turn smaller than the pitch circle of the inner teeth 21 . In addition, in the state where the planetary gear 3 is inscribed with the inner gear 2, the center C1 of the pitch circle of the outer teeth 31 is deviated from the center (rotation axis Ax1) of the pitch circle of the inner teeth 21 by the distance ΔL (see FIG. 4 ) s position. Therefore, at least a part of the outer teeth 31 and the inner teeth 21 face each other with a gap therebetween, and the entire circumferential direction does not mesh with each other. However, since the planetary gear 3 swings (revolves) around the rotation axis Ax1 inside the inner gear 2 , the outer teeth 31 and the inner teeth 21 are partially meshed with each other. That is, when the planetary gear 3 swings around the rotation axis Ax1, as shown in FIG. 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 teeth of the internal teeth 21 in the internal gear 2 is larger than the number of teeth of the external teeth 31 of the planetary gear 3 by N (N is a positive integer). In this basic structure, as an example, N is "1", and the number of teeth (of the external teeth 31 ) of the planetary gear 3 is "1" more than the number of teeth of the inner toothed gear 2 (of the internal teeth 21 ). Such a difference in the number of teeth of the planetary gear 3 and the internally toothed gear 2 defines the reduction ratio of the output rotation with respect 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 in the internally toothed gear 2 . Further, the dimension in the tooth direction (direction parallel to the rotation axis Ax1 ) of the outer teeth 31 is smaller than the dimension in the tooth direction (direction parallel to the rotation axis Ax1 ) of the inner teeth 21 . In other words, in the direction parallel to the rotation axis Ax1 , the outer teeth 31 are retracted within the range of the tooth direction of the inner teeth 21 .

In this basic structure, as described above, the rotation corresponding to the rotation component of the planetary gear 3 is taken out as the rotation (output rotation) of the output shaft integrated with the inner ring 61 of the bearing member 6 . Therefore, the planetary gear 3 is connected to the inner ring 61 by the plurality of inner pins 4 . As shown in FIGS. 5A and 5B , a plurality of inner pin holes 32 into which the plurality of inner pins 4 are inserted are formed in the planetary gear 3 . The inner pin holes 32 are provided in the same number as the inner pins 4 , and in this basic structure, as an example, 18 inner pin holes 32 and 18 inner pins 4 are each provided. Each of the plurality of inner pin holes 32 is a hole that opens in a circular shape and penetrates the planetary gear 3 in the thickness direction. A plurality of (18 here) inner pin holes 32 are arranged at equal intervals in the circumferential direction on a virtual circle concentric with the opening portion 33 .

The plurality of inner pins 4 are members that connect the planetary gear 3 and the inner ring 61 of the bearing member 6 . Each of the plurality of inner pins 4 is formed in a cylindrical shape. The diameters and lengths of the plurality of inner pins 4 are the same among the plurality of inner pins 4 . The diameter of the inner pin 4 is one turn smaller than the diameter of the inner pin hole 32 . Thereby, the inner pin 4 is inserted into the inner pin hole 32 (refer to FIG. 4 ) in a state where a margin (clearance) of a space is secured between the inner pin 4 and the inner peripheral surface 321 of the inner pin hole 32 .

The bearing member 6 has an outer ring 62 and an inner ring 61 and is used to take out the output of the gear device 1 as the rotation of the inner ring 61 with respect to the outer ring 62 . The bearing member 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 members. Both the outer ring 62 and the inner ring 61 have an annular shape that is a perfect circle in a plan view. The inner ring 61 is slightly smaller than the outer ring 62 , and is arranged 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 generated 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, 18 holding holes 611 are provided. As shown in FIGS. 6A and 6B , each of the plurality of holding holes 611 is a hole that opens in a circular shape and penetrates 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 a virtual 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 .

Further, 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, a plurality of output-side mounting holes 612 (refer to FIG. 2 ) for mounting the output shaft are formed in the inner ring 61 . 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 are arranged on a virtual circle concentric with the outer circumference of the inner ring 61 .

The outer ring 62 is fixed to a fixing member such as the case 10 together with the gear body 22 of the internally toothed gear 2 . Therefore, a plurality of through holes 621 for fixing are formed in the outer ring 62 . Specifically, as shown in FIG. 3 , in a state where the gear body 22 is sandwiched between the outer ring 62 and the housing 10 , screws (bolts) for fixing are inserted through the through holes 621 and the fixing holes 222 of the gear body 22 . ) 60 to be fixed to the housing 10.

The plurality of rolling elements 63 are arranged in the gap between the outer ring 62 and the inner ring 61 . The plurality of rolling elements 63 are arranged in parallel along the circumferential direction of the outer ring 62 . The plurality of rolling elements 63 are all metal members of the same shape, and are provided at equal intervals over the entire area of the outer ring 62 in the circumferential direction.

In this basic structure, as an example, the bearing member 6 is a crossed roller bearing. That is, the bearing member 6 has cylindrical rollers as the rolling elements 63 . In addition, the axis of the cylindrical rolling element 63 has an inclination of 45 degrees with respect to a plane orthogonal to the rotation axis Ax1 , and is orthogonal to the outer circumference of the inner ring 61 . Furthermore, a pair of rolling elements 63 adjacent to each other in the circumferential direction of the inner ring 61 are arranged in a direction whose axial direction is orthogonal to each other. In the bearing member 6 constituted by such a crossed roller bearing, the radial load, the load in the thrust direction (the direction along the rotation axis Ax1 ), and the bending force (bending moment load) with respect to the rotation axis Ax1 are easily received . Moreover, with the one bearing member 6, these three kinds of loads can be endured, and the required rigidity can be ensured.

As shown in FIGS. 7A and 7B , the eccentric shaft 7 is a cylindrical member. The eccentric shaft 7 has a shaft center portion 71 and an eccentric portion 72 . The axial center portion 71 has at least a cylindrical shape whose outer peripheral surface is a perfect circle in plan view. The center (central axis) of the shaft center portion 71 coincides with the rotation axis Ax1. The eccentric portion 72 has a disk shape whose outer peripheral surface is a perfect circle in plan view at least. The center (central axis) of the eccentric portion 72 coincides with the center C1 deviated from the rotation axis Ax1. Here, the distance ΔL (see FIG. 7B ) between the rotation axis Ax1 and the center C1 is the eccentric amount of the eccentric portion 72 with respect to the axial center portion 71 . The eccentric portion 72 has a flange shape that protrudes over the entire circumference from the outer peripheral surface of the axial center portion 71 at the center portion in the longitudinal direction (axial direction) of the axial center portion 71 . According to the above-described configuration, the eccentric shaft 7 is caused to perform eccentric movement by the shaft center portion 71 rotating (autorotating) about the rotation axis Ax1.

In this basic structure, the shaft center portion 71 and the eccentric portion 72 are integrally formed with a single metal member, thereby realizing the seamless eccentric shaft 7 . 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 swings around the rotation axis Ax1.

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

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

The eccentric body bearing 5 has an eccentric outer ring 52 and an eccentric inner ring 51, absorbs the rotation component of the rotation of the eccentric shaft 7, and is used to only rotate the eccentric shaft 7 other than the rotation component of the eccentric shaft 7, that is, A member that transmits the swing component (revolution component) of the eccentric shaft 7 to the planetary gear 3 . The eccentric body bearing 5 has a plurality of rolling elements 53 in addition to the eccentric outer ring 52 and the eccentric inner ring 51 (see FIG. 3 ).

Both the eccentric outer ring 52 and the eccentric inner ring 51 are annular members. Both the eccentric outer ring 52 and the eccentric inner ring 51 have an annular shape that is a perfect circle in plan view. 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 generated 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 parallel along the circumferential direction of the eccentric outer ring 52 . The plurality of rolling elements 53 are all metal members of the same shape, and are arranged at equal intervals over 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 corresponds to the outer diameter of the eccentric portion 72 in the eccentric shaft 7 . The eccentric body bearing 5 is combined with the eccentric shaft 7 in a state in which 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 corresponds to the inner diameter (diameter) of the opening portion 33 in 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 in a state of being attached to the eccentric portion 72 of the eccentric shaft 7 is accommodated in the opening portion 33 of the planetary gear 3 .

In this basic structure, as an example, the dimension in the width direction (direction parallel to the rotation axis Ax1 ) of the eccentric inner ring 51 of the eccentric body bearing 5 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 . Further, 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 gears 3 are accommodated within the range of the eccentric body bearing 5 in the 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 direction (direction parallel to the rotation axis Ax1 ) of the inner teeth 21 . Therefore, the eccentric body bearing 5 is received within the range of the internally toothed gear 2 in the 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 Ax1 which is offset from the center C1 of the eccentric inner ring 51 Rotation (eccentric movement). At this time, the rotational 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 . Accordingly, 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 swings around the rotation axis Ax1 .

As shown in FIGS. 8A and 8B , the support body 8 is formed in an annular shape and supports the 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. 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 is a hole that opens in a circular shape and penetrates 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 a virtual circle concentric with the outer peripheral surface 81 of the support body 8 . The diameter of the support hole 82 is 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 arrange|positioned so that it may oppose the planetary gear 3 from one side (input side) of the rotation axis Ax1. Then, 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 regulated by bringing the outer peripheral surface 81 into contact with the plurality of pins 23 . As a result, the centering of the support body 8 is performed by the plurality of pins 23 , and as a result, the centering of the plurality of pins 23 is also performed regarding the plurality of inner pins 4 supported by the supported body 8 . The support body 8 is explained in detail in the column of "(3.3) Support body".

The first bearing 91 and the second bearing 92 are respectively attached to the axial center portion 71 of the eccentric shaft 7 . Specifically, as shown in FIG. 3 , the first bearing 91 and the second bearing 92 are mounted on 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 . When viewed from the eccentric portion 72, the first bearing 91 is arranged on the input side of the rotation shaft Ax1. When viewed from the eccentric portion 72, the second bearing 92 is arranged on the output side of the rotation shaft 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 with respect 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 the direction parallel to the rotation axis Ax1.

The casing 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 casing 10 itself are formed in the flange portion 11 . In addition, a bearing hole 12 is formed in the end surface on the output side of the rotating shaft Ax1 in the housing 10 . The bearing hole 12 opens in a circular shape. The first bearing 91 is attached to the housing 10 by fitting the first bearing 91 into the bearing hole 12 .

In addition, a plurality of screw holes 13 are formed around the bearing hole 12 on the end face on the output side of the rotating shaft Ax1 of the housing 10. The plurality of screw holes 13 are used for fixing the gear body 22 of the internally toothed gear 2 and the outer ring 62 of the bearing member 6 to the housing 10 . Specifically, the fixing screw 60 is passed through the through hole 621 of the outer ring 62 and the fixing hole 222 of the gear body 22 and screwed to the threaded hole 13 , thereby fixing the gear body 22 and the outer ring 62 to the case 10 .

In addition, as shown in FIG. 3 , the gear device 1 of the present 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 on the input side of the rotating shaft Ax1 of the eccentric shaft 7 , and fills the gap between the housing 10 and the eccentric shaft 7 (axial center portion 71 ). The oil seal 15 is attached to the end portion on the output side of the rotating shaft Ax1 of the eccentric shaft 7 , and fills the gap between the inner ring 61 and the eccentric shaft 7 (axial center portion 71 ). The oil seal 16 is attached to the end face on the output side of the rotating shaft Ax1 of the bearing member 6 , and fills the gap between the inner ring 61 and the outer ring 62 . The space sealed by the plurality of oil seals 14 , 15 and 16 constitutes the lubricant holding space 17 (see FIG. 9 ). The lubricant holding space 17 includes the space between the inner ring 61 and the outer ring 62 of the bearing member 6 . Furthermore, the plurality of pins 23 , the planetary gears 3 , the eccentric body bearing 5 , the support body 8 , the first bearing 91 , the second bearing 92 , and the like are accommodated in the lubricant holding space 17 .

In addition, a lubricant is enclosed in the lubricant holding space 17 . The lubricant is liquid and can flow in the lubricant holding space 17 . Therefore, when the gear device 1 is used, for example, lubricant enters the meshing portion between the inner teeth 21 formed of the plurality of pins 23 and the outer teeth 31 of the planetary gear 3 . The "liquid" mentioned in the embodiments of the present disclosure refers to a substance in a liquid or gel state. The "gel state" as used herein refers to a state having intermediate properties of a liquid and a solid, and a state containing a colloid composed of two phases, a liquid phase and a solid phase. For example, an emulsion in which a dispersant is a liquid phase and a dispersoid in a liquid phase, a suspension in which the dispersoid is a solid phase, and the like are referred to as a gel or a sol. shape". In addition, a state in which the dispersant is in a solid phase and the dispersoid is in a liquid phase is also included in "gel-like". In this basic structure, as an example, the lubricant is a liquid lubricating oil (oil).

In the gear device 1 having the above-described configuration, the eccentric shaft 7 rotates around the rotation axis Ax1 by applying a rotational force as an input to the eccentric shaft 7, whereby the planetary gears 3 oscillate (revolve) around the rotation axis Ax1. At this time, the planetary gear 3 swings in a state in which the inner side of the inner gear 2 is inscribed with the inner gear 2 and a part of the outer teeth 31 meshes with a part of the inner teeth 21 , so the meshing position of the inner teeth 21 and the outer teeth 31 is along the The inner gear 2 moves in the circumferential direction. As a result, a 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 ). Then, the rotation (rotational component) of the planetary gear 3 excluding the swing 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, from the output shaft integrated with the inner ring 61, a rotational output reduced by a relatively high reduction ratio according to the difference in the number of teeth of the two gears can be obtained.

However, as described above, in the gear device 1 of the present embodiment, 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 reduction ratio R1 is represented by the following formula 1.

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

In short, the smaller the difference in the number of teeth (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 in the number of teeth (V1-V2) is "1". Therefore, according to the above formula 1, the reduction ratio R1 is " 51". In such a case, when the eccentric shaft 7 rotates once (360 degrees) clockwise around the rotation axis Ax1 when viewed from the input side of the rotation axis Ax1, the inner ring 61 rotates counterclockwise around the rotation axis Ax1 by a difference in the number of teeth. The amount of "1" (that is, about 7.06 degrees).

According to the gear device 1 of the present basic structure, such a high reduction ratio R1 can be realized by the combination of the primary gears (the internal gear 2 and the planetary gear 3 ).

The gear device 1 may include at least an internally toothed gear 2 , a planetary gear 3 , a plurality of inner pins 4 , a bearing member 6 , and a support body 8 , and may also include, for example, a spline bush or the like as constituent elements.

However, when the input rotation on the high-speed rotation side is accompanied by eccentric motion as in the gear device 1 of the present basic structure, if the balance of the rotating body that rotates at high speed is not balanced, vibration or the like may occur. Therefore, a balance may be used in some cases. Weights, etc. to achieve weight balance. That is, since the rotating body composed of 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 weight of the rotating body with respect to the rotation axis Ax1 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, the weight balance of the rotating body with respect to the rotating shaft Ax1 is achieved.

In short, in this basic structure, weight balance of the rotating body with respect to the rotating shaft Ax1 is achieved 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 device 1 of the present basic structure includes the eccentric body bearing 5 which is accommodated in the opening 33 formed in the planetary gear 3 and causes 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 , the rotating body composed of at least one of the eccentric inner ring 51 and the eccentric inner ring 51 rotating together has a gap 75 in a part on the center C1 side of the eccentric outer ring 52 . In this basic structure, the eccentric shaft 7 is "a member that rotates together with the eccentric inner ring 51", and corresponds to a "rotating 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 FIGS. 3 and 4 , the clearance 75 is located on the center C1 side when viewed from the rotation axis Ax1 , and thus functions to make the weight balance of the eccentric shaft 7 nearly equal from the rotation axis Ax1 to the circumferential direction.

More specifically, the void 75 includes a concave portion formed on the inner peripheral surface of the through hole 73 penetrating the rotating body along the rotating axis Ax1 of the eccentric inner ring 51 . That is, in this basic structure, since the rotating body is the eccentric shaft 7 , the concave portion formed on the inner peripheral surface of the through hole 73 passing through the eccentric shaft 7 along the rotating axis Ax1 functions as the void 75 . In this way, by utilizing the recessed portion formed on the inner peripheral surface of the through hole 73 as the void 75, the weight balance of the rotating body can be achieved without accompanying a change in the appearance.

(3.2) Rotation structure of domestic sales

Next, the rotation structure of the inner pin 4 of the gear device 1 of the present basic structure will be described in more detail with reference to FIG. 9 . FIG. 9 is an enlarged view of the region Z1 of FIG. 3 .

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

Here, since the diameter of the inner pin 4 is smaller than the diameter of the inner pin hole 32, a gap can be secured 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, the inner pin 4 is relatively movable with respect to the center of the inner pin hole 32. 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 substantially the same as the diameter of the inner pin 4 and slightly larger than the diameter of the inner pin 4 . Therefore, the movement of the inner pin 4 within the holding hole 611 is restricted, that is, the relative movement of the inner pin 4 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 in which it cannot revolve in the holding hole 611 with respect to the inner ring 61 . As a result, the swing component of the planetary gear 3 , that is, the revolution component of the planetary gear 3 is absorbed by the loose engagement between the inner pin hole 32 and the inner pin 4 , and the plurality of inner pins 4 remove the swing component (revolution component) of the planetary gear 3 . The rotation (rotation component) of the outer planetary gear 3 is transmitted to the inner ring 61 .

However, in the present basic structure, the diameter of the inner pin 4 is slightly larger than that of the holding hole 611 , so that the inner pin 4 in the state of being inserted into the holding hole 611 is prohibited from revolving in the holding hole 611 , but can be inserted into the holding hole 611 . Rotation within 611. That is, even if the inner pin 4 is inserted into the holding hole 611 , it can rotate in the holding hole 611 because it is not pressed into the holding hole 611 . As described above, in the gear device 1 of the present basic structure, 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 pin holes 32 , the inner pins 4 themselves are rotatable.

In short, in this basic structure, the inner pin 4 is held relative to the planetary gear 3 in a state capable of both revolving and autorotation in the inner pin hole 32 , and is only capable of being revolved in the holding hole 611 relative to the inner ring 61 . The state of rotation is maintained. That is, the plurality of inner pins 4 are rotatable (revolved) around the rotation axis Ax1 in a state in which their respective rotations are not restricted (rotatable state), and can revolve within 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 revolve and rotate in the inner pin holes 32 and can rotate in the holding holes 611 . Therefore, when the inner pin 4 revolves in the inner pin hole 32 , since the inner pin 4 is in a state capable of autorotation, it rolls with respect to the inner peripheral surface 321 of the inner pin hole 32 . In other words, since the inner pin 4 revolves in the inner pin hole 32 so as to roll on the inner peripheral surface 321 of the inner pin hole 32 , 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 configuration of the present basic structure, loss due to frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 is inherently difficult to occur, so the inner roller can be omitted. Therefore, in this basic structure, each of the plurality of inner pins 4 is 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 in which the inner roller is not attached 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 . As a result, the inner roller can be omitted and the diameter of the inner pin hole 32 can be kept relatively small, so that the planetary gear 3 can be reduced in size (in particular, the diameter), and the gear device 1 as a whole can be easily reduced in size. If the size of the planetary gears 3 is fixed, compared with the above-described first related art, for example, the number (number) of the inner pins 4 can be increased to smooth the transmission of rotation, or the inner pins 4 can be made thicker to increase the strength. Furthermore, the number of parts can be kept small by the amount corresponding to the inner roller, which also contributes to cost reduction of the gear device 1 .

In addition, in the gear device 1 of the present basic structure, 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 the 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 on the output side of the rotation axis Ax1 in the inner pin 4 is at the same position as the bearing member 6 in the direction parallel to the rotation axis Ax1. In short, since the end portion on the output side of the rotation shaft Ax1 of the inner pin 4 is inserted into the holding hole 611 formed in the inner ring 61 of the bearing member 6 , at least the end portion is arranged in the axial direction of the bearing member 6 with the bearing member 6 . same location.

In this way, at least a part of each of the plurality of inner pins 4 is disposed at the same position as the bearing member 6 in the axial direction of the bearing member 6 , whereby the size of the gear device 1 in the direction parallel to the rotation axis Ax1 can be kept small. That is, in the gear device 1 of the present basic structure, the number of gears in the direction parallel to the rotation axis Ax1 can be reduced as compared with the structure in which the bearing member 6 and the inner pin 4 are juxtaposed (opposed) in the axial direction of the bearing member 6 . The size of the device 1 can contribute to further miniaturization (thinning) of the gear device 1 .

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

In addition, in this basic structure, in order to make the autorotation of the inner pin 4 with respect to the inner ring 61 smoothly perform, the following structure is employ|adopted. That is, the rotation of the inner pin 4 is smoothed by interposing the lubricant (lubricating oil) 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, since the lubricant holding space 17 into which the lubricant is injected exists between the inner ring 61 and the outer ring 62 , the smooth rotation of the inner pin 4 is achieved by the lubricant in the lubricant holding space 17 .

As shown in FIG. 9 , in this basic structure, the inner ring 61 has: a plurality of holding holes 611 into which the plurality of inner pins 4 are respectively inserted; and a plurality of connecting passages 64 . The plurality of connecting passages 64 connect the lubricant holding space 17 between the inner ring 61 and the outer ring 62 and the plurality of holding holes 611 . Specifically, the inner ring 61 is formed with a connecting passage 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 connection passage 64 is a hole penetrating between the bottom surface of the concave portion (groove) in which the rolling element 63 is accommodated in the opposing surface of the inner ring 61 and the outer ring 62 and the inner peripheral surface of the holding hole 611 . In other words, the opening surface of the coupling passage 64 on the lubricant holding space 17 side is arranged 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 connection path 64 .

According to the above configuration, since the lubricant holding space 17 and the holding hole 611 are connected by the connecting passage 64 , the lubricant in the lubricant holding space 17 is supplied to the holding hole 611 through the connecting passage 64 . That is, when the bearing member 6 operates to roll the rolling elements 63 , the rolling elements 63 function as a pump and can send the lubricant in the lubricant holding space 17 to the holding holes 611 via the connecting passage 64 . In particular, when the opening surface of the coupling passage 64 on the lubricant holding space 17 side faces (opposes) the rolling elements 63 of the bearing member 6, the rolling elements 63 effectively function as pumps when the rolling elements 63 rotate. As a result, the lubricant is interposed between the inner peripheral surface of the holding hole 611 and the inner pin 4 , and the rotation of the inner pin 4 with respect to the inner ring 61 can be smoothed.

(3.3) Support body

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

First, as a premise, as described above, the support body 8 is a member that supports the plurality of inner pins 4 . That is, the support body 8 bundles the plurality of inner pins 4 to disperse the load acting on the plurality of inner pins 4 when the rotation (rotation component) of the planetary gear 3 is transmitted to the inner ring 61 . Specifically, the plurality of support holes 82 into which the plurality of inner pins 4 are respectively inserted are provided. 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 in which each of the plurality of inner pins 4 can rotate. That is, each of the plurality of inner pins 4 is held in a state capable of rotating with respect to both the inner ring 61 of the bearing member 6 and the support body 8 .

In this way, the positioning of the plurality of inner pins 4 with respect to the support body 8 is performed in both the circumferential direction and the radial direction of the support body 8 . That is, when the inner pin 4 is inserted into the support hole 82 of the support body 8 , movement in all directions in the 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) by the support body 8 .

Here, the support body 8 has at least an annular shape whose outer peripheral surface 81 is a perfect circle in plan view. In addition, the position of the support body 8 is restricted by bringing the outer peripheral surface 81 into contact with the plurality of pins 23 in the internally toothed gear 2 . Since the plurality of pins 23 constitute the internal teeth 21 of the internally toothed gear 2 , in other words, the position of the support body 8 is restricted 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 a virtual circle (addition circle) passing through the tips of the internal teeth 21 of the internally toothed gear 2 . Therefore, all of the plurality of pins 23 are in contact with the outer peripheral surface 81 of the support body 8 . Thus, in a state where the support body 8 is positionally regulated by the plurality of pins 23 , the center of the support body 8 is positionally regulated so as to overlap with the center (rotation axis Ax1 ) of the internally toothed gear 2 . As a result, the centering of the support body 8 is performed, and as a result, the centering of the plurality of inner pins 4 supported by the support body 8 is also performed by the plurality of pins 23 .

In addition, the plurality of inner pins 4 rotate (revolve) about the rotation axis Ax1 , thereby transmitting the rotation (rotation component) of the planetary gear 3 to the inner ring 61 . Therefore, the support body 8 supporting the plurality of inner pins 4 rotates about 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 in a state where the center of the support body 8 is maintained on the rotation axis Ax1. And since the support body 8 rotates in the state in which the outer peripheral surface 81 of the several pins 23 contacts, the several pins 23 rotate (autorotate) with the rotation of the support body 8, respectively. Thereby, the support body 8 constitutes a needle bearing (needle roller bearing) together with the internally toothed gear 2, and rotates smoothly.

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

Furthermore, since the support body 8 sandwiches the plurality of pins 23 between the gear bodies 22 , the support body 8 also functions as a “stopper” that suppresses movement of the pins 23 in the direction in which the pins 23 are separated from the inner peripheral surface 221 of the gear body 22 . 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, each of the plurality of pins 23 is in contact with the outer peripheral surface 81 of the support body 8 to restrict movement in the direction of separation from the gear main body 22 .

However, as shown in FIG. 9 , in this basic structure, the support body 8 is located on the opposite side to the inner ring 61 of the bearing member 6 with the planetary gear 3 interposed therebetween. 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 positioned on the input side of the rotation shaft Ax1 when viewed from the planetary gear 3 , and the inner ring 61 is positioned on the output side of the rotary shaft Ax1 when 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 through the inner pin hole 32 of the planetary gear 3 . In short, the gear device 1 of the present basic structure includes the bearing member 6 having the outer ring 62 and the inner ring 61 arranged inside the outer ring 62 , and the inner ring 61 is supported so as to be rotatable relative to the outer ring 62 . In addition, the gear body 22 is fixed to the outer ring 62 . Here, the planetary gear 3 is located between the support body 8 and the inner ring 61 in the axial direction of the support body 8 .

According to this structure, since the support body 8 and the inner ring 61 support the both ends of the longitudinal direction of the inner pin 4, the inclination of the inner pin 4 is difficult to generate|occur|produce. In particular, the bending force (bending moment load) acting on the plurality of inner pins 4 with respect to the rotation axis Ax1 is also easily received. In addition, in this basic structure, the support body 8 is sandwiched between the planetary gear 3 and the case 10 in the direction parallel to the rotation axis Ax1. Thereby, the movement of the support body 8 to the input side (left side in FIG. 9 ) of the rotation axis Ax1 is restricted by the casing 10 . The movement to the input side (left side in FIG. 9 ) of the rotation shaft Ax1 is also restricted by the housing 10 about 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 .

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 (direction parallel to the rotation axis Ax1 ). The inner ring 61 is in contact with the other end portion (the end portion on the output side of the rotational axis Ax1 ) of the pin 23 in the longitudinal direction (direction parallel to the rotational axis Ax1 ). According to this configuration, since the support body 8 and the inner ring 61 are centered at both ends in the longitudinal direction of the pin 23 , the inclination of the inner pin 4 is less likely to occur. In particular, the bending force (bending moment load) acting on the plurality of inner pins 4 with respect to the rotation axis Ax1 is also easily received.

In addition, the plurality of pins 23 have a length greater than or equal to the thickness of the support body 8 . In other words, the support body 8 is received within the range of the tooth direction of the internal teeth 21 in the direction parallel to the rotation axis Ax1. Thereby, the outer peripheral surface 81 of the support body 8 comes into contact with the plurality of pins 23 over the entire length of the tooth direction (direction parallel to the rotation axis Ax1 ) of the inner teeth 21 . Therefore, it is difficult to cause a problem such as "one-sided wear" in which the outer peripheral surface 81 of the support body 8 is locally worn.

In addition, in this basic structure, the outer peripheral surface 81 of the support body 8 is smaller in surface roughness than the one surface of the support body 8 adjacent to the outer peripheral surface 81 . That is, the surface roughness of the outer peripheral surface 81 is smaller than that of both end surfaces of the support body 8 in the axial direction (thickness direction). The "surface roughness" mentioned in the embodiments of the present disclosure refers to the roughness of the surface of the object, and the smaller the value, the smaller (less) the unevenness of the surface is and the smoother it is. In this basic structure, as an example, the surface roughness is referred to as the arithmetic equilibrium roughness (Ra). For example, the surface roughness of the outer peripheral surface 81 is smaller than that of the surface 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 the peripheral surface of the plurality of pins 23 and higher than the inner peripheral surface 221 of the gear 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 an indentation formed by pressing a steel ball with a certain pressure. Specifically, as an example of the hardness of a metal, there are Rockwell hardness (HRC), Brinell hardness (HB), Vickers hardness (HV), Shore hardness (Hs), and the like. As means for increasing the hardness (hardening) of metal parts, for example, alloying, heat treatment, and the like are exemplified. In this basic structure, as an example, the hardness of the outer peripheral surface 81 of the support body 8 is increased by processing such as carburizing and quenching. In this structure, even if the support body 8 rotates, 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 period of time.

(4) Application example

Next, application examples of the gear device 1 and the actuator 100 of the present basic configuration will be described.

The gear device 1 and the actuator 100 of the present basic structure are suitable for a robot such as a horizontal articulated robot, that is, a so-called Selective Compliance Assembly Robot Arm (SCARA: Selective Compliance Assembly Robot Arm) type robot, for example.

In addition, the application example of the gear device 1 and the actuator 100 of the present basic structure is not limited to the above-described articulated robot, and may be, for example, industrial robots other than the articulated robot, or non-industrial robots. Examples of industrial robots other than the horizontal articulated robot include a vertical articulated robot, a parallel link robot, and the like. Examples of robots other than industrial use include a home robot, a nursing robot, a medical robot, and the like.

(Embodiment 1)

＜Summary＞

As shown in FIGS. 11 to 17 , etc., the internal meshing planetary gear device 1A (hereinafter, also simply referred to as “gear device 1A”) according to the present embodiment mainly includes the structure around the main inner pin 4 and the surrounding of the input shaft (eccentric shaft 7 ). The structure is different from the gear unit 1 of the basic structure. Hereinafter, about the same structure as the basic structure, the same code|symbol is attached|subjected and description is abbreviate|omitted suitably.

FIG. 11 is a schematic cross-sectional view of the gear unit 1A. FIG. 12 is a schematic cross-sectional view of a state in which a bush 70 to be described later is removed in the gear unit 1A. FIG. 13 is a side view of the gear device 1A as viewed from the input side (the left side of FIG. 11 ) of the rotation shaft Ax1 . FIG. 11 corresponds to a cross-sectional view taken along line A1-A1 in FIG. 13 , and FIG. 12 corresponds to a cross-sectional view taken along line B1-A1 in FIG. 13 . FIG. 14 is a side view of the gear device 1A as viewed from the output side (right side in FIG. 11 ) of the rotation shaft Ax1 . In FIGS. 13 and 14 , the enlarged views of the respective Z1-Z1 line cross-sections are shown in the balloons. 15 is a schematic cross-sectional view of a state in which covers 163 and 164 and

oil seals

14 and 15 to be described later are removed in the same cross-sectional view as in FIG. 12 (corresponding to a cross-sectional view taken along line B1-A1 in FIG. 13 ). 16 is a side view of the gear unit 1A in a state in which the

covers

163 and 164 and the oil seals 14 and 15 are removed, as seen from the input side (the left side in FIG. 15 ) of the rotation shaft Ax1 . FIG. 17 is a side view of the gear unit 1A in a state in which the

covers

163 and 164 and the oil seals 14 and 15 are removed, as seen from the output side (right side in FIG. 15 ) of the rotation shaft Ax1 .

As the first major difference from the basic structure, the gear unit 1A of the present embodiment is configured so that each of the plurality of inner pins 4 can be removed in a state where at least the bearing member 6A, the inner gear 2 and the planetary gear 3 are combined. That is, the gear device 1A includes the inner pin path Sp1 (see FIG. 15 ). The inner pin path Sp1 is located on at least one side of the plurality of inner pins 4 in a direction parallel to the rotation axis Ax1 , and each inner pin of the plurality of inner pins 4 can be removed in a state in which the bearing member 6A, the inner gear 2 and the planetary gear 3 are combined. Here, the plurality of inner pins 4 are respectively 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 . Furthermore, the plurality of inner pins 4 are arranged inside the inner ring 61 (of the bearing member 6A) when viewed from a direction parallel to the rotation axis Ax1.

In addition, as the second main difference from the basic structure of the gear device 1A of the present embodiment, the structure (support structure 40 ) supporting the plurality of inner pins 4 is a structure in which both ends of the inner pins 4 are held by the rolling

bearings

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

bearings

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

bearings

41 and 42 in a rotatable state. Also, the rolling elements 402 (see FIG. 20 ) of the rolling

bearings

41 and 42 are configured to be detachable in a state in which at least the bearing member 6A, the inner gear 2 and the planetary gear 3 are combined similarly to the inner pin 4 . Specifically, the rolling elements 402 (see FIG. 20 ) of the rolling

bearings

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

In addition, as the third main difference from the basic structure of the gear device 1A of the present embodiment, the bush 70 is provided with a fixing structure 701 for fixing the target member to the eccentric shaft 7 as the input shaft. That is, the gear device 1A includes an input shaft (eccentric shaft 7 ) that eccentrically swings the planetary gear 3 , and a bush 70 . The bush 70 has a fixing structure 701 for fixing the object member, and the bush 70 is combined with the input shaft (eccentric shaft 7 ) and rotates together with the input shaft (eccentric shaft 7 ).

In short, as the main difference from the basic structure, the gear device 1A of the present embodiment newly adopts the structure around the inner pin 4, in particular, the study of the detachable inner pin 4 and the structure of the support structure 40 (rolling bearings 41, 42) for the inner pin 4. . Further, as a main difference from the basic structure, the gear unit 1A has newly adopted the structure around the input shaft (eccentric shaft 7), particularly the bush 70. 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, also 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 state capable of autorotating is the same as the basic structure.

＜Other differences＞

In addition to the above-mentioned main difference (the structure around the inner pin 4 and the structure around the input shaft), the gear device 1A of the present embodiment has a number of differences from the basic structure as described below.

As another first 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 constituted by angular contact ball bearings, respectively, and have an inner ring 61 , an outer ring 62 , and a plurality of rolling elements 63 . The inner ring 61 of the first bearing member 601A and the inner ring 61 of the second bearing member 602A each have an annular shape of a perfect circle whose outer peripheral surface is centered on the rotation axis Ax1 in a plan view. Specifically, as shown in FIG. 11 , the first bearing member 601A is disposed on the input side (left side in FIG. 11 ) of the rotating shaft Ax1 as viewed from the planetary gear 3 , and is disposed on the output side ( 11) the second bearing member 602A is arranged. The bearing member 6A is constituted by the first bearing member 601A and the second bearing member 602A such that the radial load, the thrust direction (the direction along the rotation axis Ax1 ), and the bending force (bending moment load) to the rotation axis Ax1 are all included. Tolerable.

Here, the first bearing member 601A and the second bearing member 602A are arranged in opposite directions in the direction parallel to the rotation axis Ax1 on 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 of (here, two) angular contact ball bearings are combined. Here, as an example, the first bearing member 601A and the second bearing member 602A are of the "back face combination type" that receives a load in the thrust direction (direction along the rotation axis Ax1 ) in which the inner rings 61 of the respective inner rings 61 approach each other. 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 tightening the respective inner rings 61 in the direction of approaching each other. The "preload" referred to in the embodiments of the present disclosure refers to a state in which internal stress is always applied by applying a preload, which is a so-called preload. That is, in the gear device 1A of the present embodiment, in each bearing member of the first bearing member 601A and the second bearing member 602A, the rolling elements 63 are pressed against the outer ring 62 from the outer side in the direction parallel to the rotation axis Ax1.

As another second difference, as shown in FIG. 11 , the gear device 1A of the present embodiment includes a bracket flange 18 and an output flange 19 . The carrier flange 18 and the output flange 19 are arranged on both sides in a direction parallel to the rotation axis Ax1 with respect to the planetary gear 3 , and are coupled to each other through the carrier hole 34 (see FIG. 12 ) of the planetary gear 3 . Specifically, as shown in FIG. 11 , the carrier flange 18 is disposed on the input side (left side in FIG. 11 ) of the rotating shaft Ax1 as viewed from the planetary gear 3 , and on the output side of the rotating shaft Ax1 as viewed from the planetary gear 3 ( FIG. 11 ) 11 ) is provided with an output flange 19 . The inner ring 61 of the bearing member 6A (each of the first bearing member 601A and the second bearing member 602A) is fixed to the bracket flange 18 and the output flange 19 . In the present embodiment, as an example, the inner ring 61 of the first bearing member 601A is seamlessly integrated with the bracket 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 (for example, six) bracket pins 191 (see FIG. 12 ) protruding from one surface of the output flange 19 toward the input side of the rotation axis Ax1 . The plurality of carrier pins 191 respectively penetrate the carrier holes 34 formed in the planetary gear 3 (six as an example), and the tips of the plurality of carrier pins 191 are connected to the carrier flange 18 by carrier bolts 181 (see FIG. 12 ). fixed. Here, the diameter of the bracket pin 191 is slightly smaller than the diameter of the bracket hole 34, and a gap is ensured between the bracket pin 191 and the inner peripheral surface of the bracket hole 34 so that the bracket pin 191 can move in the bracket hole 34, that is, Relatively movable with respect to the center of the bracket hole 34 . Further, the gap between the bracket pin 191 and the inner peripheral surface of the bracket 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 bracket pin 191 does not connect with the bracket hole. The inner peripheral surface of 34 is in contact. 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 bracket pin 191 (see Fig. 17 ).

Here, both ends of the inner pin 4 are not directly held by the inner ring 61 of the bearing member 6A, but are held by the bracket flange 18 and the output flange 19 (via the rolling bearings 41 and 42 ) 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 because they are held by the bracket flange 18 and the output flange 19 .

Thus, the gear device 1A is used by taking out 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 gears 3 and the inner gear 2 is extracted as the rotation component of the planetary gears 3 from the inner ring 61 coupled to the planetary gears 3 by the inner pins 4 . In contrast, in the present embodiment, the relative rotation between the planetary gear 3 and the internally toothed 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 device 1A is used in a state in which the outer ring 62 of the bearing member 6A is fixed to a housing serving as a fixing member. That is, the planetary gear 3 is connected to the carrier flange 18 and the output flange 19 as rotating members by the plurality of inner pins 4 , and the gear body 22 is fixed to the stationary member, so the relative rotation between the planetary gear 3 and the inner gear 2 is prevented from The rotating members (the bracket flange 18 and the output flange 19) are taken out. In other words, in the present embodiment, when the plurality of inner pins 4 rotate relative to the gear body 22 , the rotational force of the holder flange 18 and the output flange 19 is taken out as an output.

As another third difference, in the present embodiment, the housing 10 is seamlessly integrated with the gear body 22 of the internally toothed gear 2 . That is, in the basic structure, the gear main body 22 of the internally toothed 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 the present embodiment, the gear main body 22 serving as the fixing member is provided continuously and seamlessly with the housing 10 in the direction parallel to the rotation axis Ax1.

More specifically, the casing 10 is cylindrical, and constitutes the outer contour of the gear device 1A. In the present embodiment, the central axis of the cylindrical casing 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 of the rotation axis Ax1 directions). The casing 10 is formed in a cylindrical shape opened at both end surfaces in the direction of the rotation axis Ax1. Here, the housing 10 and the gear main body 22 of the internally toothed gear 2 are seamlessly integrated, so that the housing 10 and the gear main body 22 are handled as one component. Therefore, the inner peripheral surface of the housing 10 includes the inner peripheral surface 221 of the gear body 22 . Furthermore, 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 to the input side (left side in FIG. 11 ) of the rotation shaft Ax1 by fitting, as viewed from the gear body 22 in the inner peripheral surface of the housing 10 . On the other hand, the outer ring 62 of the second bearing member 602A is fixed to the output side of the rotating shaft Ax1 (right side in FIG. 11 ) by fitting, as viewed from the gear body 22 on the inner peripheral surface of the housing 10 .

Further, the end face on the input side (the left side in FIG. 11 ) of the rotation axis Ax1 of the casing 10 is closed by the bracket flange 18 , and the end face on the output side (the right side in FIG. 11 ) of the rotation shaft Ax1 of the casing 10 is closed by the output Flange 19 to occlude. Therefore, as shown in FIGS. 11 and 12 , in the space surrounded by the housing 10 , the bracket flange 18 and the output flange 19 , the planetary gear 3 , the plurality of inner pins 4 , the plurality of pins 23 , and the eccentric body are accommodated Bearings 5 and other components. Here, the oil seal 161 fills the gap between the bracket flange 18 and the housing 10 , and the oil seal 162 fills the gap between the output flange 19 and the housing 10 . The space sealed by the plurality of oil seals 14 , 15 , 161 , and 162 constitutes the lubricant holding space 17 (see FIG. 11 ) similarly to the basic structure. A plurality of installation holes 111 for fixing the case 10 itself are formed in both end surfaces in the direction parallel to the rotation axis Ax1 in the case 10 .

As another fourth 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 gears 3 include the first planetary gears 301 and the second planetary gears 302 which are juxtaposed in the 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 gears 301 and the second planetary gears 302 , the center C1 of the first planetary gear 301 located on the input side (left side in FIG. 11 ) of the rotation axis Ax1 is positioned relative to the rotation axis Ax1 A state in which it deviates (offsets) toward the top of the graph. On the other hand, the center C2 of the second planetary gear 302 on the output side (right side in FIG. 11 ) of the rotation axis Ax1 is deviated (offset) downward in the figure with respect to the rotation axis Ax1 . In this way, the plurality of planetary gears 3 are equally arranged in the circumferential direction with the rotation axis Ax1 as the center, whereby the 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 clearance 75 of the eccentric shaft 7 is omitted (see FIG. 3 ).

More specifically, the eccentric shaft 7 has two eccentric parts 72 for one axial part 71 . The centers (central axes) of the two eccentric portions 72 coincide with the centers C1 and C2 deviated from the rotation axis Ax1 , respectively. In addition, the shapes of the first planetary gears 301 and the second planetary gears 302 themselves are the same. In addition, the eccentric body bearing 5 in a state of being mounted on the eccentric portion 72 centered on the center C1 is accommodated in the opening portion 33 of the first planetary gear 301 . The eccentric body bearing 5 in a state of being mounted on the eccentric portion 72 centered on the center C2 is accommodated in the opening portion 33 of the second planetary gear 302 . 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 second planetary gear 302 relative to the rotation axis Eccentricity of Ax1.

18 and 19 show the states of the first planetary gear 301 and the second planetary gear 302 at a certain time. FIG. 18 is a cross-sectional view taken along the line A1-A1 of FIG. 11 , showing the first planetary gear 301 . FIG. 19 is a cross-sectional view taken along line B1-B1 of FIG. 11 , showing the second planetary gear 302 . However, in FIGS. 18 and 19 , illustration of the retainer 54 is omitted, and hatching is omitted even in cross-section. As shown in FIGS. 18 and 19 , in the first planetary gear 301 and the second planetary gear 302 , their centers C1 and C2 are rotationally symmetrical at 180 degrees 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 in the directions viewed from the rotation axis Ax1, but their absolute values are the same. According to the above-described configuration, the shaft center portion 71 rotates (rotates) around the rotation axis Ax1, whereby the first planetary gear 301 and the second planetary gear 302 surround the rotation axis Ax1 with a phase difference of 180 degrees around the rotation axis Ax1. Rotation (eccentric movement).

As another fifth difference, as shown in Fig. 11 , in the present embodiment, the eccentric body bearing 5 is constituted by a roller bearing instead of the deep groove ball bearing as described in the basic structure. That is, in the gear device 1A of the present embodiment, the eccentric body bearing 5 uses cylindrical (cylindrical) rollers as the rolling elements 53 . Furthermore, in the present 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 planetary gear 3 (the opening portion 33 ) 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 . . In the present embodiment, the eccentric body bearing 5 has a retainer 54, and each of the plurality of rolling elements 53 is held by the retainer 54 in a state capable of rotating itself. The retainer 54 holds the plurality of rolling elements 53 at equal intervals in the circumferential direction of the eccentric portion 72 . Furthermore, the retainer 54 is not fixed with respect to the planetary gear 3 and the eccentric shaft 7 , but can rotate relative to each of the planetary gear 3 and the eccentric shaft 7 . Accordingly, the plurality of rolling elements 53 held by the retainer 54 move in the circumferential direction of the eccentric portion 72 in accordance with the rotation of the retainer 54 .

As another sixth difference, as shown in FIG. 11 , the gear device 1A of the present 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 whose outer peripheral surface is a perfect circle in plan view at least. In addition, the position of the support ring 8A is regulated by bringing the outer peripheral surface into contact with the plurality of pins 23 of the internally toothed gear 2 . Since the plurality of pins 23 constitute the internal teeth 21 of the internally toothed gear 2 , in other words, the position of the support ring 8A is regulated 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 a virtual circle (addition circle) passing through the tips of the internal teeth 21 of the internally toothed gear 2 . Therefore, all of the plurality of pins 23 are in contact with the outer peripheral surface of the support ring 8A. Thereby, the center of the support ring 8A is positionally regulated so as to overlap with the center (rotation axis Ax1 ) of the internally toothed gear 2 in a state where the support ring 8A is positionally regulated by the plurality of pins 23 .

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 with the rotation (rotation) of the planetary gear 3 . At this time, since the support ring 8A rotates in a state in which the outer peripheral surface of the support ring 8A is in contact with the plurality of pins 23, the plurality of pins 23 rotate (autorotate) in accordance with the rotation of the support ring 8A. Thereby, the support ring 8A constitutes a needle bearing (needle roller bearing) together with the internally toothed gear 2, and rotates smoothly. That is, if the gear body 22 of the internally toothed gear 2 is regarded as an "outer ring" and the support ring 8A is regarded as an "inner ring", the plurality of pins 23 interposed therebetween serve as "rolling elements (rollers)" " to function. In this way, the support ring 8A constitutes a needle bearing together with the internally toothed gear 2 (the gear main body 22 and the plurality of pins 23 ), and can rotate smoothly. Furthermore, since the support ring 8A sandwiches the plurality of pins 23 between the gear bodies 22 , the support ring 8A also functions as a “stopper” that suppresses movement of the pins 23 in the direction in which the pins 23 are separated from the inner peripheral surface 221 of the gear body 22 . .

As another seventh 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 respectively arranged 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 at least an annular shape whose inner peripheral surface is a perfect circle in plan view. The spacer 55 functions as a "presser" of the eccentric body bearing 5, and restricts the movement of the eccentric body bearing 5 (particularly, the retainer 54) in a direction parallel to the rotation axis Ax1.

Here, the spacer 55 secures a gap with respect to the first bearing 91 and the second bearing 92 and the outer rings thereof. Therefore, in the first bearing 91 and the second bearing 92 , their outer rings are not in contact with the spacer 55 , but 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 members 6A, secure clearances with the planetary gears 3 . Therefore, the first bearing member 601A and the second bearing member 602A are not in contact with the planetary gears 3 .

As another eighth difference, the gear device 1A of the present embodiment is configured so that a preload is applied from the planetary gears 3 to each of the inner pins 4 when the plurality of inner pins 4 are not rotating with respect to the inner gear 2 . That is, in the gear device 1A, when the plurality of inner pins 4 are non-rotating with respect to the internally toothed 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 , thereby The pre-pressure acts on each of the plurality of inner pins 4 . Here, in the gear unit 1A, each of the plurality of inner pins 4 is supported by the support structure 40 (rolling bearings 41, 42) so as to maintain the state in which the preload is applied. The support structure 40 supports the respective inner pins of the plurality of inner pins 4 to counteract the moment generated by the respective inner pins of the plurality of inner pins 4 due to the preload.

With 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 state where the inner pin 4 is separated from the planetary gear 3 is difficult to occur. Therefore, when the gear device 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 a state where the gear unit is assembled in consideration of assembly tolerances and the like, when the gear unit is not driven, a clearance is ensured between the inner peripheral surface of the inner pin hole and the inner pin, but the gear unit 1A of the present embodiment dares to be configured as Eliminate this gap. Therefore, according to the gear device 1A of the present embodiment, it is possible to reduce or eliminate at least the backlash generated by the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 , thereby easily suppressing the angle transmission error to a small value . In particular, in the gear device 1A with a high reduction ratio, even if there is a backlash due to a slight backlash, the error of the rotation of the output side (output flange 19 ) with respect to the rotation of the input side (eccentric shaft 7 ) is not enough. That is to say, the angle transmission error also increases, so the effect of reducing or eliminating the backlash is large.

In addition to the above points, for example, regarding the number of teeth of the internal gear 2 and the planetary gear 3, the reduction ratio, the number of the inner pin holes 32 and the inner pin 4, and the specific shapes and dimensions of each part, the present embodiment and the The basic structure is also appropriately different. For example, 18 of the inner pin holes 32 and the inner pins 4 are each provided in the basic structure, but in the present embodiment, 6 are provided each as an example.

Next, the structure around the inner pin 4 in the gear device 1A of the present embodiment will be described in more 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 along with the eccentric motion of the planetary gear 3 . The movement amount of the inner pin 4 at this time is twice the eccentric amount ΔL1 (=ΔL2 ) in the linear direction (for example, the vertical direction in FIG. 11 ) orthogonal to the rotation axis Ax1 . That is, the diameter Di of the inner pin hole 32 is ideally represented 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 in a state where a margin of space (clearance) is secured between the inner pin 4 and the inner peripheral surface 321 of the inner pin hole 32 . However, it is difficult to set the diameter di of the inner pin 4 and the diameter Di of the inner pin hole 32 according to the design value (ideal value), and there are slight deviations 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 increases, and backlash due to the gap occurs, thereby increasing the angle transmission error . 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, so that the gear device 1A's loss becomes larger.

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

In other words, since at least one side of the plurality of inner pins 4 in the direction parallel to the rotation axis Ax1 can be opened through the inner pin passage Sp1, the plurality of inner pins 4 can be detached through the opened portion (inner pin passage Sp1). of each domestic sales. In addition, by removing the inner pin 4, replacement of the inner pin 4 and the like can be performed. That is, after disassembling the inner pin 4 , by reassembling the other inner pin 4 or the same inner pin 4 after maintenance (grinding, cleaning, etc.), at least the bearing member 6A, the inner gear 2 and the planetary gear 3 can be combined in a state. Replacement of inner pin 4, etc. The reassembled inner pin 4 is also inserted through the inner pin passage Sp1 as in the case of disassembly.

In short, according to the above-described configuration, in the gear device 1A of the present embodiment, 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 between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 can be reduced or eliminated. Therefore, it is easy to suppress the angle transmission error to a small value. 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 kept small, and the loss of the gear unit 1A can be easily suppressed. be small. In particular, in the gear device 1A with a high reduction ratio, even if there is a backlash due to a slight backlash, the error of the rotation of the output side (output flange 19 ) with respect to the rotation of the input side (eccentric shaft 7 ) is not enough. That is to say, the angle transmission error becomes large, so the effect of reducing or eliminating the backlash is large.

Furthermore, according to the configuration of the present embodiment, the angle transmission error at the time of starting the gear unit 1A from the stopped state to the start of rotation can be reduced, so that the starting characteristics of the gear unit 1A can be greatly improved, and the gear unit 1A can be greatly improved. responsiveness at startup or when the direction of rotation is switched. As a result, for example, in the field of robotics, even in fields where stopping, starting, or switching of the rotational direction is frequently performed and the requirements for angular transmission errors are severe, the gear device 1A can exhibit sufficient characteristics.

Furthermore, in the present embodiment, each of the plurality of inner pins 4 is held by the inner ring 61 in a state capable of autorotating. However, strictly speaking, each inner pin 4 is not directly held by the inner ring 61 , but is held by the bracket flange 18 and the output flange 19 (via the rolling bearings 41 and 42 ) integrated with the inner ring 61 , and thus is held by the bearing member The inner ring 61 of 6A is held indirectly. In this way, according to the structure in which the inner pin 4 is kept rotatable, even if the gap between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 is small, the inner pin 4 is pressed against the inner peripheral surface 321 of the inner pin hole 32 in the inner pin hole 32 revolves inside, and the inner pin 4 also rolls with respect to the inner peripheral surface 321 of the inner pin hole 32 . In other words, since the inner pin 4 revolves in the inner pin hole 32 so as to roll on the inner peripheral surface 321 of the inner pin hole 32 , 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.

Furthermore, the plurality of inner pins 4 are arranged inside the inner ring 61 (of the bearing member 6A) when viewed from 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). In this way, since the plurality of inner pins 4 are arranged inside the bearing member 6A, the inner pins 4 can be removed as long as the inner pin passage Sp1 is secured inside the bearing member 6A. Specifically, holes into which the plurality of inner pins 4 are inserted are formed in the bracket 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 Realize the path Sp1 for domestic sales. According to this configuration, it is possible to suppress an increase in the size of the gear device 1A in the radial direction (direction orthogonal to the rotation axis Ax1 ).

In addition, as shown in FIG. 15 , in the gear device 1A of the present embodiment, 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 (the left side in FIG. 15 ) of the rotation axis Ax1 and the output side (the 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 is self-removable from either the input side or the output side of the rotation axis Ax1. Furthermore, the inner pin 4 can also be removed from the other side in the direction parallel to the rotation axis Ax1 so that the existing inner pin 4 is pressed from one side in the direction parallel to the rotation axis Ax1. Therefore, when replacing the inner pin 4, for example, the existing inner pin 4 can be removed from the output side of the rotation shaft Ax1 so that the existing inner pin 4 is pushed from the input side of the rotation shaft Ax1 by the new inner pin 4. Insert the new inner pin 4 at the same time.

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

covers

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

covers

163 and 164 are detachably attached to the bracket flange 18 and the output flange 19, for example. Specifically, the cover body 163 is detachably attached to the bracket flange 18 and covers the inner pin path Sp1 on the input side of the rotating shaft Ax1 in a state of being attached to the bracket flange 18 . The cover 164 is detachably attached to the output flange 19 , and covers the inner pin path Sp1 on the output side of the rotary shaft Ax1 in a state of being attached to the output flange 19 .

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

cover bodies

163 and 164 . The

covers

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

covers

163 and 164 are attached to the bracket flange 18 and the output flange 19 (the states in FIGS. 11 and 12 ) corresponds to the “first position”, and the state from the bracket flange 18 and the output flange 19 corresponds to the “first position” 19 The disassembled state (the state of FIG. 15 ) corresponds to the "second position". The

cover bodies

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

In addition, the

cover bodies

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 the present embodiment, as an example, six inner pins 4 are provided, and therefore six inner pin paths Sp1 are also provided on the input side and the output side of the rotation axis Ax1, respectively. The cover body 163 is configured to cover the six inner pin paths Sp1 on the input side of the rotation axis Ax1 collectively, rather than cover them individually. Similarly, the cover body 164 is configured to cover the six inner pin paths Sp1 on the output side of the rotary shaft Ax1 collectively, not to cover them individually. Therefore, when the cover 163 is removed, as shown in FIG. 16 , the six inner pin paths Sp1 on the input side of the rotating shaft Ax1 are exposed, and when the cover 164 is removed, as shown in FIG. 17 , the output side of the rotating shaft Ax1 is exposed. The six internal pin paths Sp1 are exposed.

Specifically, each of the

cover bodies

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

covers

163 and 164 are restricted by bringing their outer peripheral surfaces into contact with the bracket flange 18 and the output flange 19 . That is, each of the bracket flange 18 and the output flange 19 has a dimple opened toward the outside in the direction parallel to the rotation axis Ax1. The

cover bodies

163 and 164 are attached to the bracket flange 18 and the output flange 19 so as to be fitted into these recesses. Furthermore, oil seals 14 and 15 are fitted inside the

covers

163 and 164 . That is, the

cover bodies

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

covers

163 and 164 .

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

covers

163 and 164 are attached to the bracket flange 18 and the output flange 19 with a plurality of (an example, six) attachment screws 160 . That is, the cover body 163 is fixed to the bracket flange 18 by being fixed to the screw holes 183 (refer to FIG. 16 ) of the bracket flange 18 with six mounting screws 160 in a state of being fitted into the recess of the bracket flange 18 . The cover body 164 is fixed to the output flange 19 by being fastened to the screw holes 193 (see Fig. 17 ) of the output flange 19 with six mounting screws 160 in a state of being fitted into the recess of the output flange 19. The

cover bodies

163 and 164 are made of metals such as stainless steel, cast iron, carbon steel for machine structure, chrome molybdenum steel, phosphor bronze, or aluminum bronze, as in other parts.

As shown in FIG. 13 , opening holes 165 are formed in the cover body 163 . The opening holes 165 are provided at respective positions corresponding to the bracket bolts 181 in a state in which the cover body 163 is attached to the bracket flange 18 . In this embodiment, since there are six bracket bolts 181, six opening holes 165 are also provided. The opening hole 165 functions as a release hole for releasing the head of the bracket bolt 181 . In addition, as shown in FIG. 14 , an opening hole 166 is formed in the cover 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 the present 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 through which the flange bolt hole 192 is exposed.

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

cover bodies

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

covers

163 and 164 facing the bracket flange 18 and the output flange 19 , respectively.

Recesses

184 and 194 are provided on the opposite surfaces of the bracket flange 18 and the output flange 19 to the covers 163 and 164 (that is, the bottom surfaces of the recesses) and at positions corresponding to the projections 167 , respectively. The cover body 163 is combined with the bracket flange 18 so that the convex portion 167 is fitted into the concave portion 184 of the bracket flange 18 , and is thereby moved relative to the inner ring 61 of the first bearing member 601A integrated with the bracket flange 18 . relative positioning. Similarly, the cover body 164 is combined with the output flange 19 so that the convex portion 167 is fitted into the concave portion 194 of the output flange 19 , and thereby the inner ring 61 of the second bearing member 602A integrated with the output flange 19 is integrated with the output flange 19 . are relatively positioned.

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

cover bodies

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

cover bodies

163 and 164 can be restricted with high accuracy. In the present embodiment, in particular, the positions of the oil seals 14 and 15 when viewed from a direction parallel to the rotation axis Ax1 are restricted by the

covers

163 and 164. Therefore, by improving the positional accuracy of the

covers

163 and 164, it is possible to suppress the oil seals 14 and 15. The centering is not good. 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 that the positioning structure uniquely determines the relative positions of the

cover bodies

163 and 164 and the inner ring 61 in the rotation direction with the rotation axis Ax1 as the center. Accordingly, when the rotation axis Ax1 is used as the axis of symmetry, the

covers

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

cover bodies

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

In addition, in the present 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 the bearing member 6A at least partially in the direction parallel to the rotation axis Ax1 . That is, as shown in FIG. 15 , at least one part of the plurality of sets of rolling

bearings

41 and 42 serving as the support structure 40 for holding (supporting) the inner pin 4 is located between the first bearing member 601A and the second bearing in the direction parallel to the rotation axis Ax1 The location where the member 602A is repeated. That is, in the direction parallel to the rotation axis Ax1, at least a part of the rolling bearing 41 is at the same position as the first bearing member 601A, and at least a part of the rolling bearing 42 is at the same position as the second bearing member 602A. In particular, in the present embodiment, the dimension in the width direction (direction parallel to the rotation axis Ax1 ) of the first bearing member 601A and the second bearing member 602A is substantially the same as the dimension in the width direction of the rolling

bearings

41 and 42 . Therefore, in the direction parallel to the rotation axis Ax1, approximately the respective bearing members of the first bearing member 601A and the second bearing member 602A are accommodated within the respective ranges of the rolling

bearings

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

bearings

41 and 42 .

In this way, in the present 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 the installation space of the support structure 40 indicating the inner pin 4 . Therefore, it is possible to suppress an increase in the size of the gear device 1A in the 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 and 42 ) is arranged on the outer side of the inner bearing member (the first bearing 91 and the second bearing 92 ), and the bearing member 6A (the first bearing member 601A and the second bearing member 6A) 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 possible to suppress an increase in the size of the gear device 1A in the radial direction (direction orthogonal to the rotation axis Ax1 ) due to the provision of the rolling

bearings

41 and 42 .

Moreover, the path Sp1 for inner pins communicates with the lubricant holding space 17 which holds the lubricant. Specifically, the inner pin path Sp1 passes through the hole for insertion of the inner pin 4 of the bracket flange 18 and the output flange 19 and is connected to the lubricant holding space 17 . According to this configuration, the lubricant can be supplied to the lubricant holding space 17 from the inner pin path Sp1 when the inner pin 4 is replaced or the like.

However, in the present embodiment, the pair of rolling

bearings

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

bearings

41 and 42 has a retainer 401 and a plurality of rolling elements 402 . The outer ring 403 of each of the rolling

bearings

41 and 42 also serves as the bracket flange 18 and the output flange 19 . Specifically, the inner peripheral surface of the hole for insertion of the inner pin 4 of the bracket flange 18 and the output flange 19 functions as the outer ring 403 of each of the rolling

bearings

41 and 42 . The outer ring 403 is perfectly circular in plan view, and the inner diameter of the outer ring 403 is 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 . The plurality of rolling elements 402 are arranged in the gap between the outer ring 403 and the inner pin 4 . The plurality of rolling elements 402 are arranged in parallel along the circumferential direction of the outer ring 403 . The plurality of rolling elements 402 are all metal members of the same shape, and are provided at equal intervals over the entire area of the outer ring 403 in the circumferential direction. The cage 401 holds the plurality of rolling elements 402 at equal intervals in the circumferential direction of the outer ring 403 .

In the present embodiment, each of the rolling

bearings

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

bearings

41 and 42 has cylindrical rollers as the rolling elements 402 . In addition, the axes of the cylindrical rolling elements 402 are all arranged parallel to the rotation axis Ax1. In the present embodiment, each of the rolling

bearings

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

bearings

41 and 42 , the inner pin 4 is rotated relative to the outer ring 403 by the rolling of the plurality of rolling elements 402 , and the rolling

bearings

41 and 42 can hold the inner pin 4 rotatably.

According to this configuration, the inner pin 4 can rotate, and the loss due to frictional resistance between the inner peripheral surface 321 of the inner pin hole 32 and the inner pin 4 is unlikely to occur, so the inner roller can be omitted. Therefore, in the present embodiment, the inner pin 4 in which the inner roller is not attached 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 . As a result, the inner roller can be omitted and the diameter of the inner pin hole 32 can be kept relatively small, so that the planetary gear 3 can be reduced in size (especially, the diameter), and the entire gear device 1A can be easily reduced in size. Furthermore, each inner pin 4 is held by a pair of rolling

bearings

41 and 42 . Therefore, when the inner pin 4 rotates, loss due to frictional resistance between the inner pin 4 and the bracket flange 18 and the output flange 19 is less likely to occur.

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

bearings

41 and 42 viewed from the 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 a virtual circle VC1 passing through the center of each of the plurality of inner pins 4 is set when viewed from a direction parallel to the rotation axis Ax1 , the plurality of sets of rolling

bearings

41 and 42 are arranged in the virtual circle VC1 . circle on VC1. In the present embodiment, particularly as shown in FIG. 20 , when viewed from a direction parallel to the rotation axis Ax1 , the plurality of sets of rolling

bearings

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

That is, the plurality of sets of rolling

bearings

41 and 42 are arranged on the virtual circle VC1 at equal intervals in the circumferential direction of the virtual circle VC1. That is to say, viewed from a direction parallel to the rotation axis Ax1, the virtual circle VC1 passes through the respective centers of the plurality of rolling bearings 41 (or 42), and the virtual circle VC1 between two adjacent rolling bearings 41 (or 42) is on the virtual circle VC1 The distance is uniform for 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 and 42 , and the force applied to the plurality of inner pins 4 can be equally distributed when the gear device 1A is driven.

Furthermore, as shown in FIG. 20 , in the present embodiment, the center of a virtual circle VC1 passing through the centers of the plurality of sets of rolling

bearings

41 and 42 coincides with the rotation axis Ax1 when viewed from a direction parallel to 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, the center of the pitch circle of the internal teeth 21, and the like, and is located on the rotation axis Ax1. With this configuration, the center of the gear body 22 of the internally toothed gear 2 and the plurality of inner pins 4 are easily maintained on the rotation axis Ax1 with high accuracy with respect to the rotational center of the internally toothed gear 2 . As a result, in the gear device 1A, there is an advantage that inconveniences such as generation of vibration and reduction in transmission efficiency due to poor centering are less likely to occur.

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

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

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

Specifically, the bush 70 has an annular shape whose inner peripheral surface is a perfect circle when viewed at least. The center (central axis) of the bushing 70 coincides with the rotation axis Ax1. The end portion on the output side of the rotating shaft Ax1 in the bush 70 constitutes an insertion port 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 so that the end portion on the input side of the rotation axis Ax1 of the axial center portion 71 of the eccentric shaft 7 is fitted into the insertion port 702 . That is, in the present embodiment, the bush 70 has the insertion port 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 port 702 . The material of the bushing 70 is the same as that of the other components, and is a metal such as stainless steel, cast iron, carbon steel for mechanical structure, chrome molybdenum steel, phosphor bronze or aluminum bronze.

In addition, the bush 70 is coupled to the eccentric shaft 7 by press-fitting in a state in which a part of the eccentric shaft 7 is inserted into (fitted into) the insertion port 702 . Further, the bushing 70 is combined with the input shaft at least by gluing. Specifically, the bush 70 is firmly coupled to the eccentric shaft 7 by 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. Thereby, firm coupling between the bushing 70 and the eccentric shaft 7 can be 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 at the end portion on the input side of the rotation axis Ax1 of the eccentric shaft 7 . Here, the bush 70 is positioned on the input side of the rotation shaft Ax1 as viewed from the first bearing 91 as the inner bearing member. Thereby, the first bearing 91 serving as the inner bearing member is located at a position sandwiched between the eccentric portion 72 and the bush 70 in the direction parallel to the rotation axis Ax1 . Thereby, the bush 70 functions as a "press" of the first bearing 91, and restricts the movement of the inner bearing member (the first bearing 91) in the direction parallel to the rotation axis Ax1. In short, the gear device 1A of the present embodiment includes an inner bearing member (first bearing 91 ) that holds the input shaft (eccentric shaft 7 ) rotatably (indirectly) with respect to the inner ring 61 . The bush 70 restricts the movement of the inner bearing member (first bearing 91 ) to one side in the direction parallel to the rotation axis Ax1 .

Furthermore, in the present embodiment, the input shaft (eccentric shaft 7 ) and the bush 70 have the through-hole 73 penetrating along the rotation axis Ax1 . That is, the through hole 73 penetrates through the bush 70 from the axial center portion 71 of the eccentric shaft 7 along the rotation axis Ax1. Here, since the fixing structure 701 for fixing the target member is provided on the bush 70, if the outer diameter of the eccentric shaft 7 is the same, it is easier to ensure a larger diameter of the through hole 73 than when the bush 70 is not provided. That is, since there is no need to provide a fixing structure to the eccentric shaft 7 itself, the thickness of the eccentric shaft 7 (the core portion 71 ) is easily reduced, and as a result, the through hole 73 is easily enlarged.

In the present embodiment, as an example, the fixing structure 701 is constituted by a screw hole. That is, the target member can be fixed to the bush 70 by screwing the target member to the screw hole as the fixing structure 701 . Here, the fixing structure 701 (threaded hole) is provided on the end surface 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 the target member can be fixed with a plurality of screws. When the target member is fixed using such a fixing structure 701 , the target member is fixed to 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 target member on one side of the direction parallel to the rotation axis Ax1 with respect to the bushing 70 .

In addition, in the present embodiment, at least a part of the fixed structure 701 is at the same position as the input shaft in the 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 target member overlaps with the input shaft (eccentric shaft 7 ) in the direction parallel to the rotation axis Ax1 . As a result, although the fixed structure 701 is relatively large, it is possible to suppress an increase in the size of the gear device 1A in the direction parallel to the rotation axis Ax1.

Furthermore, in the present embodiment, the inner pin path Sp1 is provided, but the inner pin path Sp1 enables the removal of the inner pin 4 even in a state in which the bush 70 and the eccentric shaft 7 are kept coupled. That is, the gear device 1A includes an inner pin path Sp1 that is located on at least one side of a direction parallel to the rotation axis Ax1 with respect to the plurality of inner pins 4 and that is connected between the input shaft (eccentric shaft 7 ) and the bush 70 In the combined state, each inner pin of the plurality of inner pins 4 can be removed. Accordingly, in the gear device 1A, even after the bush 70 is input to the input shaft (eccentric shaft 7 ), each of the plurality of inner pins 4 can be detached.

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

bearings

41 and 42 in the gear device 1A of the present embodiment will be described with reference to FIGS. 21 and 22 . Here, as an example, a description will be given of a case where an operator replaces the inner pin 4, the rolling

bearings

41, 42, etc. 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 .

Even when replacing any one of the inner pin 4 and the rolling element 402, the operator removes the mounting screw 160 to remove the

covers

163, 164 and the oil seals 14, 15 from the bracket flange 18 and the output flange 19 (see FIG. 15). By removing the

cover bodies

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

As shown in FIG. 21 , when the inner pin 4 is replaced, the operator pushes the new inner pin 4A into the bracket flange 18 from, for example, the inner pin path Sp1 on the input side of the rotation axis Ax1 . At this time, the existing inner pin 4 pressed by the new inner pin 4A is pushed out to the output side of the rotating shaft Ax1. Then, in a state where the new inner pin 4A is completely inserted, the existing inner pin 4 is removed. In this method, since at least one of the new inner pin 4A and the existing inner pin 4 is always inserted into each of the rolling

bearings

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

bearings

41 and 42 are prevented from falling off by the

inner pins

4 and 4A.

Furthermore, in the above-described method, since the inner pins 4 can be replaced one by one, each time one inner pin 4 is replaced, the gear unit 1A can be experimentally driven and performance (backlash, input torque, etc.) can be checked. Thereby, for example, there is an advantage that it is easy to specify the inner pin 4 having a defect, and it is easy to adjust the performance of the gear device 1A to a desired performance.

When replacing the rolling elements 402 , as shown in FIG. 22 , the operator pulls out the existing rolling elements 402 from the inner pin path Sp1 on the output side of the rotary shaft 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 new rolling elements 402 from the inner pin path Sp1 on the output side of the rotary shaft Ax1.

Furthermore, in the above-described method, since the rolling elements 402 can be replaced one by one, each time one rolling element 402 is replaced, the gear device 1A can be experimentally driven and performance (backlash, input torque, etc.) can be checked. Thereby, for example, there are advantages that the rolling elements 402 having a defect can be easily specified and the performance of the gear unit 1A can be easily adjusted to the desired performance.

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

covers

163 and 164 and the oil seals 14 and 15 to the bracket flange 18 and the output flange 19 after the replacement is completed. By attaching the

covers

163 and 164, the inner pin path Sp1 is closed.

However, the method illustrated in FIG. 21 is merely an example, and the operator may press-fit the new inner pin 4A into the output flange 19 from, for example, the inner pin path Sp1 on the output side of the rotating shaft Ax1. Furthermore, even when the inner pin 4 is replaced, the operator can temporarily pull out the inner pin 4 and then replace it with a new inner pin 4A, similarly to the rolling elements 402 . In addition, the inner pin 4 and the rolling elements 402 may be replaced at the same time.

Furthermore, the replacement work of the inner pin 4, the rolling

bearings

41, 42, etc. is not limited to the manufacturing process of the gear device 1A, but may be performed, for example, in maintenance work or the like during the use of the gear device 1A. That is, the maintenance method of the gear device 1A of the present embodiment includes replacing the plurality of inner pins 4 from at least one side in the direction parallel to the rotation axis Ax1 in a state in which the bearing member 6A, the inner gear 2 and the planetary gear 3 are combined. At least one process of multiple internal pins 4. In addition, the manufacturing method of the gear device 1A of the present embodiment includes a step of inserting the plurality of inner pins 4 from at least one side in the 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. 23 , the gear device 1A of the present embodiment constitutes a joint device 200 for a robot together with the first member 201 and the second member 202 . In other words, the joint device 200 for a robot of the present embodiment includes the gear device 1A, the first member 201 and the second member 202 . The first member 201 is fixed by the outer ring 62 . The second member 202 is fixed by the inner ring 61 . FIG. 23 is a schematic cross-sectional view of the joint device 200 for a robot.

In the present 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 the plurality of installation holes 111 formed in the housing 10 . The second member 202 is fixed to the bracket flange 18 and thus indirectly fixed by the inner ring 61 of the bearing member 6A.

The thus-configured joint device 200 for a robot functions as a joint device by relatively rotating the first member 201 and the second member 202 around the rotation axis Ax1. Here, the first member 201 and the second member 202 are relatively rotated by driving the eccentric shaft 7 of the gear device 1A with the first motor 203 as the drive source 101 (see FIG. 1 ). At this time, the rotation (input rotation) generated by the drive source 101 is decelerated at a relatively high reduction ratio in the gear device 1A, and the first member 201 or the second member 202 is driven with a relatively high torque. That is to say, the first member 201 and the second member 202 connected by the gear device 1A are capable of bending and extending around the rotation axis Ax1.

More specifically, the first pulley P1 is fixed to the output shaft of the first motor 203 . The second pulley P2 is connected to the first 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 target member. That is, when the first motor 203 is driven, its rotation is transmitted to the eccentric shaft 7 serving as the input shaft via the first pulley P1, the timing belt T1, and the second pulley P2.

In addition, the joint device 200 for a robot 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 through hole 73 and penetrates the bush 70 and the eccentric shaft 7 . A fifth pulley P5 is fixed to the end 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 joint device 200 for a robot is used for a robot such as a horizontal articulated robot (articulated robot), for example. Furthermore, the robot joint device 200 is not limited to the articulated robot, and can be used for industrial robots other than the articulated robot, robots other than industrial robots, and the like, for example. In addition, the gear device 1A of the present embodiment is not limited to the joint device 200 for a robot, but can be used for vehicles such as an automated guided vehicle (AGV) as a wheel device such as an in-wheel motor, for example.

The first embodiment is only one of various implementations of the embodiments of the present disclosure. Embodiment 1 Various changes can be made in accordance with designs 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 respective ratios of the sizes and thicknesses of the structural elements in the drawings are not necessarily limited to reflect the actual size ratios. Hereinafter, modifications of the first embodiment will be listed. The modifications described below can be used in combination as appropriate.

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

In addition, the inner pin 4 is not necessarily held by the rolling

bearings

41 and 42 at both ends, and only one end may be held by the rolling

bearings

41 and 42 .

In addition, the path Sp1 for inner pins may be located on at least one side of the direction parallel to the rotation axis Ax1 with respect to the plurality of inner pins 4, and does not necessarily need to be located on both sides. In addition, the

cover bodies

163 and 164 are not essential, and can be appropriately omitted. Furthermore, the

cover bodies

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

cover bodies

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

In addition, the bush 70 does not necessarily have to have the insertion port 702, and the insertion port 702 can be appropriately omitted. Furthermore, the bush 70 does not necessarily have to be bonded to the input shaft (eccentric shaft 7 ) by bonding, and may be bonded only by press-fitting, for example. In addition, it is not essential that the bush 70 restricts the movement of the inner bearing member (the first bearing 91 ) to the side in the direction parallel to the rotation axis Ax1 . Furthermore, the input shaft (eccentric shaft 7 ) and the through hole 73 of the bush 70 are not necessarily required. In addition, it is not necessary that at least a part of the fixing structure 701 be 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 from a direction parallel to the rotation axis Ax1. Furthermore, when viewed from a direction parallel to the rotation axis Ax1, the center of the virtual circle VC1 passing through the centers of the plurality of sets of rolling

bearings

41 and 42 does not need to coincide with the rotation axis Ax1.

In addition, the number of the inner pins 4 and 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 may be appropriately changed.

In addition, the bearing member 6A may be a crossed roller bearing or a deep groove ball bearing similarly to the basic structure. However, it is preferable that the bearing member 6A, such as a four-point contact ball bearing, can withstand radial loads, loads in the thrust direction (directions along the rotation axis Ax1), and bending forces (bending moment loads) with respect to the rotation axis Ax1. by.

In addition, the eccentric body bearing 5 is not limited to the roller ball bearing, and may be, for example, a deep groove ball bearing, an angular contact ball bearing, or the like.

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

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

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

In addition, the gear device 1A may include inner rollers. That is, in the gear device 1A, each of the plurality of inner pins 4 does not necessarily 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 such a case, the inner roller is fitted to the inner pin 4 so as to be able to rotate on the inner pin 4 as an axis.

In addition, each of the plurality of inner pins 4 may be held by the inner ring 61 in a rotatable state, and it is not essential for the gear device 1A that each of the plurality of inner pins 4 is held by the rolling

bearings

41 and 42 . For example, each of the plurality of inner pins 4 may be directly held by the inner ring 61, or may be directly held by the bracket flange 18 integrated with the inner ring 61, the output flange 19, or the like.

In addition, the support ring 8A is not necessary for the gear device 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 device 1A may adopt at least one of the study of the detachable inner pin 4, the study of the support structure 40 (rolling bearings 41, 42) of the inner pin 4, and the study of the bush 70, but not all of them. That is, the gear device 1A may employ, for example, only any one of the study on the detachable inner pin 4 and the study on the bush 70 .

Furthermore, the gear device 1A only needs to employ at least one of the study of the preload for the inner pin 4 and the study of the support structure 40 of the inner pin 4 , and other structures can be appropriately omitted or changed according to the basic structure. For example, in the gear device 1A, as in the first related art, the inner pin 4 may be held in a press-fitted state with respect to the inner ring 61 (or the bracket flange 18 or the output flange 19 integrated with the inner ring 61 ). . In such a case, each of the plurality of inner pins 4 is held in a state of being unable to rotate with respect to the inner ring 61 . In addition, each of the plurality of inner pins 4 may be arranged at the same position as the bearing member 6A in the axial direction of the bearing member 6A.

The input shaft to which the bushing 70 is coupled may be configured to eccentrically oscillate the planetary gear 3 during rotation, and is not limited to the configuration of the eccentric shaft 7 integrally including the shaft center portion 71 and the eccentric portion 72 . For example, the input shaft to which the bushing 70 is coupled may be the axial center portion 71 formed separately from the eccentric portion 72. In such a case, the eccentric portion 72 is attached to the input shaft (the axial center portion 71) to which the bushing 70 is coupled. .

In addition, the positioning structure for relatively positioning the

cover bodies

163 and 164 and the inner ring 61 is not limited to uniquely determining the relative positions of the

cover bodies

163 and 164 and the inner ring 61 in the rotation direction about the rotation axis Ax1. In the positioning structure, for example, the

housings

163 and 164 may be positioned rotationally symmetrically with respect to the inner ring 61 of the bearing member 6A when the rotation axis Ax1 is the axis of symmetry. Further, the positioning structure is not limited to the convex portion 167 and the

concave portions

184 and 194 , and may be realized by, for example, a fitting tolerance with respect to the bracket flange 18 and the output flange 19 . Furthermore, the positioning structure is not an essential structure, and can be appropriately omitted.

In addition, the fixing structure 701 provided in the bushing 70 is not limited to a screw hole, and may be, for example, a stud bolt, an adhesive surface, or the like.

In addition, the space between the

cover bodies

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

(Summarize)

As described above, the internal meshing planetary gear device (1, 1A) of the first aspect includes the bearing member (6, 6A), the internal gear (2), the planetary gear (3), the plurality of inner pins (4), and the inner pin path (Sp1). The bearing member (6, 6A) has 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 rotatable relative to the outer ring (62) by a rotational axis ( Ax1) is the center of relative rotation. The internal gear (2) has internal teeth (21) and is fixed to the outer ring (62). The planetary gear (3) has external teeth (31) partially meshed with the internal teeth (21). The plurality of inner pins (4) are disposed on the inner side of the inner ring (61) when viewed from a direction parallel to the rotation axis (Ax1), and are inserted into the plurality of inner pin holes (32) formed in the planetary gear (3), respectively, While revolving in the inner pin hole (32), it rotates relative to the inner tooth gear (2). The inner pin path (Sp1) is located on at least one side of the direction parallel to the rotation axis (Ax1) with respect to the plurality of inner pins (4), and is provided with the bearing members (6, 6A), the inner gear (2) and the planetary gear (3) ) in the combined state can disassemble each inner pin of the plurality of inner pins (4).

According to this aspect, the replacement of the inner pin (4) and the like can be performed without disassembling the bearing member (6, 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, it is possible to reduce or eliminate at least the difference between the inner peripheral surface (321) of the inner pin hole (32) and the inner peripheral surface (321) of the inner pin hole (32). The backlash caused by the gap between the inner pins (4) can suppress the angle transmission error to a small value. As a result, it is possible to provide an internal meshing planetary gear device (1, 1A) that can easily suppress an angle transmission error to a small value.

In the internal meshing planetary gear device (1, 1A) of the second aspect, in addition to the first aspect, the inner pin path (Sp1) is located in a direction parallel to the rotation axis (Ax1) with respect to the plurality of inner pins (4). both sides.

According to this aspect, each of the plurality of inner pins (4) can be removed from either the input side or the output side of the rotary shaft (Ax1).

On the basis of the first or second form, the internal meshing planetary gear device (1, 1A) of the third form further includes a cover body (163, 164), and the cover body (163, 164) It moves between the first position covered by Sp1) and the second position exposed by the inner pin path (Sp1).

According to this aspect, by covering the inner pin path (Sp1) with the cover (163, 164) normally, the inner pin (4) can be easily prevented from falling out through the inner pin path (Sp1).

In the internal meshing planetary gear device (1, 1A) of the fourth aspect, in addition to the third aspect, the cover body (163, 164) faces the plurality of inner pin paths corresponding to the inner pin (4) at the first position (Sp1) for pooled coverage.

According to this aspect, the movement operation of the cover bodies (163, 164) is easy.

On the basis of the third or fourth form, the internal meshing planetary gear device (1, 1A) of the fifth form further includes a positioning structure for relatively positioning the cover body (163, 164) and the inner ring (61).

According to this aspect, it is possible to improve the positional accuracy of the covers (163, 164).

In the internal meshing planetary gear device (1, 1A) of the sixth form, on the basis of the fifth form, the positioning structure uniquely determines the rotation axis (Ax1) between the cover body (163, 164) and the inner ring (61) The relative position in the rotational direction of the center.

According to this aspect, the positional accuracy of the cover bodies (163, 164) can be further improved.

In the internal meshing planetary gear device (1, 1A) of the seventh aspect, in addition to any one of the first to sixth aspects, each of the plurality of inner pins (4) is held by the inner ring (61) in a rotatable state.

According to this aspect, the inner pin (4) revolves in the inner pin hole (32) so as to roll on the inner peripheral surface (321) of the inner pin hole (32). 321) and the loss caused by the frictional resistance between the inner pin (4).

On the basis of the seventh form, the meshing planetary gear device (1, 1A) of the eighth form further includes a plurality of sets of rolling bearings (41, 42), the plurality of sets of rolling bearings (41, 42) relative to the planetary gear (3) The respective inner pins of the plurality of inner pins (4) are held on both sides in the direction in which the rotation axis (Ax1) is parallel.

According to this aspect, when the inner pin (4) rotates, a loss due to frictional resistance is less likely to occur.

In the internal meshing planetary gear device (1, 1A) of the ninth aspect, in addition to the eighth aspect, the rolling elements (402) of the rolling bearings (41, 42) in the direction parallel to the rotation axis (Ax1) can be Disassemble to the side opposite to the planetary gear (3) with respect to the outer ring (62).

According to this aspect, the rolling elements ( 402 ) of the rolling bearings ( 41 , 42 ) can also be replaced or the like.

In the internal meshing planetary gear device (1, 1A) of the tenth aspect, in addition to any one of the first to ninth aspects, each of the plurality of inner pins (4) is in a direction parallel to the rotation axis (Ax1), at least A part is held by the inner ring (61) at the same position as the bearing members (6, 6A).

According to this aspect, the dimension in the direction parallel to the rotation axis (Ax1) can be kept small.

In the internal meshing planetary gear device (1, 1A) of the eleventh aspect, in addition to any one of the first to tenth aspects, the inner pin path (Sp1) communicates with the lubricant holding space (17) holding the lubricant .

According to this aspect, the lubricant can be replenished through the inner pin path (Sp1).

The robot joint device (200) of the twelfth aspect includes: the internal meshing planetary gear device (1, 1A) of any one of the first to eleventh aspects; and a first member (201) fixed by the outer ring (62). ; and a second member (202) fixed by the inner ring (61).

According to this aspect, it is possible to provide a joint device (200) for a robot that can easily suppress an angle transmission error to a small value.

The maintenance method of the first three forms is used for an internal meshing planetary gear device (1, 1A) including a bearing member (6, 6A), an internal gear (2), a planetary gear (3), and a plurality of internal pins (4). The bearing member (6, 6A) has 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 rotatable relative to the outer ring (62) by a rotational axis ( Ax1) is the center of relative rotation. The internal gear (2) has internal teeth (21) and is fixed to the outer ring (62). The planetary gear (3) has external teeth (31) partially meshed with the internal teeth (21). The plurality of inner pins (4) are disposed on the inner side of the inner ring (61) when viewed from a direction parallel to the rotation axis (Ax1), and are inserted into the plurality of inner pin holes (32) formed in the planetary gear (3), respectively, While revolving in the inner pin hole (32), it rotates relative to the inner tooth gear (2). The maintenance method includes: in a state in which the bearing member (6, 6A), the inner gear (2) and the planetary gear (3) are combined, with respect to the plurality of inner pins (4) from at least one of the directions parallel to the rotation axis (Ax1). A process of replacing at least one or more inner pins (4) on the side.

According to this aspect, it is possible to provide a maintenance method that can easily keep the angle transmission error small.

The manufacturing method of the internal meshing planetary gear device (1, 1A) of the first and fourth forms includes the internal meshing of a bearing member (6, 6A), an internal gear (2), a planetary gear (3) and a plurality of internal pins (4). A method of manufacturing a planetary gear device (1, 1A). The bearing member (6, 6A) has 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 rotatable relative to the outer ring (62) by a rotational axis ( Ax1) is the center of relative rotation. The internal gear (2) has internal teeth (21) and is fixed to the outer ring (62). The planetary gear (3) has external teeth (31) partially meshed with the internal teeth (21). The plurality of inner pins (4) are disposed on the inner side of the inner ring (61) when viewed from a direction parallel to the rotation axis (Ax1), and are inserted into the plurality of inner pin holes (32) formed in the planetary gear (3), respectively, While revolving in the inner pin hole (32), it rotates relative to the inner tooth gear (2). A method of manufacturing an internal meshing planetary gear device (1, 1A) comprising: in a state where a bearing member (6, 6A), an internal gear (2) and a planetary gear (3) are combined, from a direction parallel to a rotation axis (Ax1) The process of inserting a plurality of inner pins (4) on at least one side of the device.

According to this aspect, it is possible to provide a method of manufacturing the internal meshing planetary gear device ( 1 , 1A) that can easily keep the angle transmission error small.

The structures of the second to eleventh aspects are not necessarily provided for the internal meshing planetary gear device (1, 1A), and can be appropriately omitted. In addition, the structures of the second to eleventh aspects can also be applied in combination to a maintenance method or a manufacturing method of an internal meshing planetary gear device (1, 1A).

Description of reference numerals

1. 1A internal meshing planetary gear device

2 internal gears

3 planetary gears

4 domestic sales

6. 6A bearing components

17 Lubricant keeps space

21 internal teeth

31 external teeth

32 inner pin holes

41, 42 rolling bearings

61 inner ring

62 outer ring

163, 164 cover

167 convex part (positioning structure)

184, 194 recess (positioning structure)

200 robot joint device

201 First Member

202 Second Member

402 rolling element

Ax1 axis of rotation

Sp1 domestic sales path

Industrial Applicability

Claims

An internal meshing planetary gear device, comprising:

a bearing member having an outer ring and an inner ring disposed inside the outer ring, and supporting the inner ring to be rotatable relative to the outer ring about a rotation axis;

an internal tooth gear, which has internal teeth and is fixed to the outer ring;

a planetary gear having external teeth partially meshed with the internal teeth;

A plurality of inner pins are disposed inside the inner ring when viewed from a direction parallel to the rotation axis, and are inserted into the inner pin holes formed in the planetary gears while being inserted into the inner pin holes, respectively. The revolving side rotates relatively with respect to the internal gear; and

The inner pin path is located on at least one side in a direction parallel to the rotation axis with respect to the plurality of inner pins, and is capable of being combined in a state in which the bearing member, the inner gear and the planetary gear are combined. Remove each inner pin of the plurality of inner pins.
The internal meshing planetary gear arrangement of claim 1, wherein:

The inner pin path is located on both sides in a direction parallel to the rotation axis with respect to the plurality of inner pins.
The internal meshing planetary gear device according to claim 1 or 2, wherein,

The internal meshing planetary gear device further includes a cover body movable between a first position covering the inner pin path and a second position exposing the inner pin path.
The internal meshing planetary gear arrangement of claim 3, wherein:

The cover body collectively covers the plurality of inner pin paths corresponding to the plurality of inner pins at the first position.
The internal meshing planetary gear device according to claim 3 or 4, wherein,

The internal meshing planetary gear device further includes a positioning structure, and the positioning structure relatively positions the cover body and the inner ring.
The internal meshing planetary gear arrangement of claim 5, wherein:

The positioning structure uniquely determines the relative position of the cover body and the inner ring in the rotation direction centered on the rotation axis.
The internal meshing planetary gear device according to any one of claims 1 to 6, wherein:

Each of the plurality of inner pins is held by the inner ring in a state capable of rotating.
The internal meshing planetary gear arrangement of claim 7, wherein:

The internal meshing planetary gear device further includes a plurality of sets of rolling bearings that hold respective inner pins of the plurality of inner pins at both sides in a direction parallel to the rotation axis with respect to the planetary gear.
The internal meshing planetary gear arrangement of claim 8, wherein:

The rolling elements of the rolling bearing are detachable to the side opposite to the planetary gear with respect to the outer ring in a direction parallel to the rotation axis.
The internal meshing planetary gear device according to any one of claims 1 to 9, wherein:

In a direction parallel to the rotation axis, at least a part of each of the plurality of inner pins is held by the inner ring at the same position as the bearing member.
The internal meshing planetary gear device according to any one of claims 1 to 10, wherein:

The passage for the inner pin communicates with the lubricant holding space for holding the lubricant.
A joint device for a robot, comprising:

The internal meshing planetary gear device according to any one of claims 1 to 11;

a first member secured to the outer race; and

A second member fixed to the inner ring.
A maintenance method in which,

The maintenance method is used for an internal meshing planetary gear device and includes a step of: in a state in which the bearing member, the internal gear, and the planetary gear are combined, with respect to the plurality of internal pins. at least one inner pin of the plurality of inner pins is replaced on at least one side of the direction in which the rotation axis is parallel,

The internal meshing planetary gear device includes:

a bearing member having an outer ring and an inner ring disposed inside the outer ring, and supporting the inner ring so as to be rotatable relative to the outer ring about a rotation axis;

an internal tooth gear, which has internal teeth and is fixed to the outer ring;

planetary gears having external teeth partially meshing with the internal teeth; and

A plurality of inner pins are disposed inside the inner ring when viewed from a direction parallel to the rotation axis, and are inserted into the inner pin holes formed in the planetary gears while being inserted into the inner pin holes, respectively. The revolving side rotates relatively with respect to the internal gear.
A manufacturing method of an internal meshing star gear device,

The internal meshing planetary gear device includes:

a bearing member having an outer ring and an inner ring disposed inside the outer ring, and supporting the inner ring so as to be rotatable relative to the outer ring about a rotation axis;

an internal tooth gear, which has internal teeth and is fixed to the outer ring;

a planetary gear having external teeth partially meshed with the internal teeth;

A plurality of inner pins are disposed inside the inner ring when viewed from a direction parallel to the rotation axis, and are inserted into the inner pin holes formed in the planetary gear while being inserted into the inner pin holes, respectively. The revolving side rotates relative to the internal gear,

Wherein, the manufacturing method of the internal meshing star gear device has the following steps:

The plurality of inner pins are inserted from at least one side in a direction parallel to the rotation axis in a state in which the bearing member, the inner gear, and the planetary gear are combined.