JP2022169213A - Internal meshing planetary gear device, robot articulation device, maintenance method and manufacturing method for internal meshing planetary gear device - Google Patents

Abstract

To provide an internal meshing planetary gear device capable of reducing an angular transmission error, a robot articulation device, a maintenance method and a manufacturing method for an internal meshing planetary gear device.SOLUTION: An internal meshing planetary gear device 1A comprises a bearing member 6A, an internal gear 2, a planetary gear 3, a plurality of inner pins 4, and an inner pin path Sp1. The plurality of inner pins 4 rotates relatively to the internal gear 2 while revolving inside a plurality of loose holes formed in the planetary gear 3 in a state where they are arranged inside an inner ring 61 when viewed in a direction parallel to a rotation axis Ax1 and are inserted into the plurality of loose holes. The inner pin path Sp1 allows each of the plurality of inner pins 4 to be removed in a state where it is positioned on at least one side of the plurality of inner pins 4 in a direction parallel to the rotation axis Ax1, and the bearing member 6A, the internal gear 2, and the planetary gear 3 are combined.SELECTED DRAWING: Figure 15

Description

TECHNICAL FIELD The present disclosure generally relates to an internal meshing planetary gear system, a joint system for a robot, a maintenance method, and a method of manufacturing an internal meshing planetary gear system, and more particularly, having external teeth inside an internal gear having internal teeth. The present invention relates to an internal meshing planetary gear device in which planetary gears are arranged, a joint device for a robot, a maintenance method, and a method of manufacturing an internal meshing planetary gear device.

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

The internal gear is constructed by rotatably incorporating a plurality of outer pins (roller pins) each forming an internal tooth into the inner peripheral surface of a gear body (internal gear body) that also serves as a casing. A plurality of loose fitting holes (inner roller holes) are formed in the planetary gear at appropriate intervals in the circumferential direction, and the inner pins and inner rollers are inserted into the loose fitting holes. The inner pin is connected to the carrier at one axial end thereof, and the carrier is rotatably supported by the casing via a cross roller bearing. This gear device can be used as a gear device that extracts from the carrier the rotation corresponding to the rotation component of the planetary gear when the internal gear is fixed.

JP-A-2003-74646

In the configuration of the above-described related technology, a gap is secured between the inner peripheral surface of the loose fitting hole and the inner roller in a state in which the gear device is assembled in consideration of assembly tolerance and the like. Further, a gap is also secured 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 depending on the application of the gear device, for example, a joint device for a robot, the angular transmission error of the gear device may become a problem.

An object of the present disclosure is to provide an internal meshing planetary gear device, a joint device for a robot, a maintenance method, and a method of manufacturing an internal meshing planetary gear device that can easily suppress angular transmission errors.

An internally meshing planetary gear device according to one aspect of the present disclosure includes a bearing member, an internal gear, a planetary gear, a plurality of inner pins, and inner pin passages. The bearing member has an outer ring and an inner ring arranged inside the outer ring, and the inner ring is supported so as to be relatively rotatable about the rotation axis with respect to the outer ring. The internal gear has internal teeth and is fixed to the outer ring. The planetary gear has external teeth that partially mesh with the internal teeth. The plurality of inner pins are arranged inside the inner ring when viewed in a direction parallel to the rotation shaft, and are inserted into the plurality of loose fitting holes formed in the planetary gear. while revolving around the internal gear. The inner pin path is located on at least one side of the plurality of inner pins in a direction parallel to the rotation axis, and in a state in which the bearing member, the internal gear, and the planetary gear are combined, Each of the plurality of inner pins is detachable.

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

A maintenance method according to an aspect of the present disclosure is used for an internally meshing planetary gear device that includes a bearing member, an internal gear, a planetary gear, and a plurality of inner pins. The bearing member has an outer ring and an inner ring arranged inside the outer ring, and the inner ring is supported so as to be relatively rotatable about the rotation axis with respect to the outer ring. The internal gear has internal teeth and is fixed to the outer ring. The planetary gear has external teeth that partially mesh with the internal teeth. The plurality of inner pins are arranged inside the inner ring when viewed in a direction parallel to the rotation shaft, and are inserted into the plurality of loose fitting holes formed in the planetary gear. while revolving around the internal gear. The maintenance method includes, in a state in which the bearing member, the internal gear, and the planetary gear are combined, removing the plurality of inner pins from at least one side in a direction parallel to the rotation axis with respect to the plurality of inner pins. Replacing at least one of the pins.

A method of manufacturing an internally meshing planetary gear device according to an aspect of the present disclosure is a method of manufacturing an internally meshing planetary gear device that includes a bearing member, an internal gear, a planetary gear, and a plurality of inner pins. The bearing member has an outer ring and an inner ring arranged inside the outer ring, and the inner ring is supported so as to be relatively rotatable about the rotation axis with respect to the outer ring. The internal gear has internal teeth and is fixed to the outer ring. The planetary gear has external teeth that partially mesh with the internal teeth. The plurality of inner pins are arranged inside the inner ring when viewed in a direction parallel to the rotation shaft, and are inserted into the plurality of loose fitting holes formed in the planetary gear. while revolving around the internal gear. The method for manufacturing the internally meshing planetary gear device includes removing the plurality of inner pins from at least one side in a direction parallel to the rotation shaft in a state in which the bearing member, the internal gear, and the planetary gear are combined. a step of inserting the

Advantageous Effects of Invention According to the present disclosure, it is possible to provide an internal meshing planetary gear device, a robot joint device, a maintenance method, and a manufacturing method of an internal meshing planetary gear device that can easily suppress an angle transmission error.

FIG. 1 is a perspective view showing a schematic configuration of an actuator including an internal meshing planetary gear device according to a basic configuration. FIG. 2 is a schematic exploded perspective view of the internal meshing planetary gear device as seen from the output side of the rotary shaft. FIG. 3 is a schematic cross-sectional view of the internal meshing planetary gear device of the same. FIG. 4 is a cross-sectional view taken along line A1-A1 of FIG. 3, showing the internal meshing planetary gear device of the same. FIG. 5A is a perspective view showing a single planetary gear of the internal meshing planetary gear device; FIG. 5B is a front view showing a single planetary gear of the internal meshing planetary gear device; FIG. 6A is a perspective view showing a single bearing member of the internally meshing planetary gear device; FIG. 6B is a front view showing a single bearing member of the internal meshing planetary gear device; FIG. 7A is a perspective view showing an eccentric shaft alone of the internal meshing planetary gear device; FIG. 7B is a front view showing an eccentric shaft alone of the internal meshing planetary gear device; FIG. 8A is a perspective view showing a single support body of the internal meshing planetary gear device of the same. FIG. 8B is a front view showing a single supporting body of the internal meshing planetary gear device of the same. FIG. 9 is an enlarged view of area Z1 in FIG. 3 showing the internal meshing planetary gear system of FIG. 10 is a cross-sectional view taken along the line B1-B1 of FIG. 3, showing the internal meshing planetary gear device of the same. FIG. 11 is a schematic cross-sectional view of the internally meshing planetary gear device according to Embodiment 1. FIG. 12 is a cross-sectional view taken along the line B1-A1 of FIG. 13, showing the internal meshing planetary gear device of the same. FIG. 13 is a side view of the internal meshing planetary gear device as viewed from the input side of the rotary shaft. FIG. 14 is a side view of the internal meshing planetary gear device as viewed from the output side of the rotating 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 internal meshing planetary gear device of the same. FIG. 16 is a side view of the internal meshing planetary gear device as seen from the input side of the rotary shaft, showing a state in which the cover body and the oil seal are removed. FIG. 17 is a side view of the internal meshing planetary gear device as seen from the output side of the rotating shaft, showing a state in which the cover body and the oil seal are removed. 18 is a cross-sectional view taken along line A1-A1 of FIG. 11, showing the internal meshing planetary gear device of the same. FIG. 19 is a cross-sectional view taken along line B1-B1 of FIG. 11, showing the internal meshing planetary gear device of the same. FIG. 20 is an explanatory diagram showing the arrangement of rolling bearings in the internal meshing planetary gear device of the same. FIG. 21 is a schematic explanatory diagram showing a procedure for replacing an inner pin in the internally meshing planetary gear device of the same. FIG. 22 is a schematic explanatory diagram showing a procedure for exchanging rolling elements in the internal meshing planetary gear device of the same. FIG. 23 is a schematic cross-sectional view showing a robot joint device using the internal meshing planetary gear device of the above.

(basic configuration)
(1) Overview An overview of the internal meshing planetary gear device 1 according to the basic configuration will be described below with reference to FIGS. 1 to 3. FIG. The drawings referred to in this disclosure are all schematic diagrams, and the ratio of the size and thickness of each component in the drawing does not necessarily reflect the actual dimensional ratio. For example, the tooth profile, dimensions, number of teeth, etc. of the internal teeth 21 and the external teeth 31 in FIGS. not on purpose.

An internal meshing planetary gear device 1 (hereinafter also simply referred to as "gear device 1") according to the present basic configuration is a gear device including an internal gear 2, a planetary gear 3, and a plurality of inner pins 4. . In this gear device 1 , a planetary gear 3 is arranged inside an annular internal gear 2 , and an eccentric body bearing 5 is arranged inside the planetary gear 3 . The eccentric bearing 5 has an eccentric inner ring 51 and an eccentric outer ring 52, and the eccentric inner ring 51 rotates around a rotation axis Ax1 (see FIG. 3) deviated from the center C1 (see FIG. 3) of the eccentric inner ring 51. The planetary gear 3 is oscillated by (eccentric motion). The eccentric inner ring 51 rotates (eccentrically moves) around the rotation axis Ax1, for example, when the eccentric shaft 7 inserted into the eccentric inner ring 51 rotates. The internally 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 supported to be relatively rotatable with respect to the outer ring 62 .

The internal gear 2 has internal teeth 21 and is fixed to the outer ring 62 . In particular, in this basic configuration, the internal gear 2 has an annular gear body 22 and a plurality of outer pins 23 . A plurality of outer pins 23 are held on the inner peripheral surface 221 of the gear body 22 in a rotatable state, and constitute the inner teeth 21 . The planetary gear 3 has external teeth 31 that partially mesh with the internal teeth 21 . That is, the planetary gear 3 is inscribed with the internal gear 2 inside the internal gear 2 , and a portion of the external teeth 31 meshes with a portion of the internal teeth 21 . In this state, when the eccentric shaft 7 rotates, the planetary gear 3 oscillates, and the engagement position between the internal tooth 21 and the external tooth 31 moves in the circumferential direction of the internal gear 2, and the planetary gear 3 and the internal gear move. 2 generates relative rotation between the two gears (the internal gear 2 and the planetary gear 3). Here, if the internal gear 2 is fixed, the planetary gear 3 will rotate (rotate) with the relative rotation of both gears. As a result, from the planetary gear 3, a rotational output reduced at a relatively high reduction ratio is obtained in accordance with the difference in the number of teeth between the two gears.

This type of gear device 1 is used so as to take out the rotation corresponding to the rotation component of the planetary gear 3 as the rotation of the output shaft integrated with the inner ring 61 of the bearing member 6, for example. As a result, the gear device 1 functions as a gear device with a relatively high reduction ratio, with the eccentric shaft 7 on the input side and the output shaft on the output side. Therefore, in the gear device 1 according to this basic configuration, the planetary gear 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 gear 3 to the inner ring 61 of the bearing member 6. connect. The plurality of inner pins 4 are inserted into the plurality of loose fitting holes 32 formed in the planetary gear 3 and rotate relatively to the internal gear 2 while revolving in the loose fitting holes 32 . . That is, the loose fitting hole 32 has a larger diameter than the inner pin 4 , and the inner pin 4 can move to revolve inside the loose fitting hole 32 while being inserted into the loose fitting hole 32 . The oscillation component of the planetary gear 3 , that is, the revolution component of the planetary gear 3 is absorbed by the loose fitting between the loose fitting hole 32 of the planetary gear 3 and the inner pin 4 . In other words, the oscillating component of the planetary gear 3 is absorbed by the plurality of inner pins 4 revolving inside the plurality of loose fitting holes 32 . Therefore, the rotation (rotational component) of the planetary gear 3 excluding the oscillation component (revolution component) of the planetary gear 3 is transmitted to the inner ring 61 of the bearing member 6 by the plurality of inner pins 4 .

By the way, in this type of gear device 1, the rotation of the planetary gear 3 is transmitted to the plurality of inner pins 4 while the inner pin 4 revolves in the loose fit hole 32 of the planetary gear 3. , an inner roller mounted on the inner pin 4 and rotatable about the inner pin 4 is known. That is, in the first related art, the inner pin 4 is held in a state of being press-fitted into the inner ring 61 (or the carrier integrated with the inner ring 61 ), and the inner pin 4 moves through the loose fitting hole 32 . When revolving, the inner pin 4 slides on the inner peripheral surface 321 of the loose fitting hole 32 . Therefore, as a first related technique, an inner roller is used in order to reduce loss due to frictional resistance between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4 . However, in the case of a configuration including an inner roller as in the first related art, the loose fitting hole 32 needs to have a diameter that allows the inner pin 4 with the inner roller to revolve, and the loose fitting hole 32 needs to be made smaller. Have difficulty. If it is difficult to reduce the size of the loose fitting hole 32 , it hinders the reduction in size (especially the diameter reduction) of the planetary gear 3 , and thus the reduction in size of the gear device 1 as a whole. The gear device 1 according to this basic configuration can provide an internal meshing planetary gear device 1 that can be easily miniaturized by the following configuration.

That is, the gear device 1 according to this basic configuration includes a bearing member 6, an internal gear 2, a planetary gear 3, and a plurality of inner pins 4, as shown in FIGS. 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 rotatably supported relative to the outer ring 62 . The internal gear 2 has internal teeth 21 and is fixed to the outer ring 62 . The planetary gear 3 has external teeth 31 that partially mesh with the internal teeth 21 . The plurality of inner pins 4 are inserted into the plurality of loose fitting holes 32 formed in the planetary gear 3 , and rotate relatively to the internal gear 2 while revolving inside the loose fitting holes 32 . Here, each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state. Furthermore, at least a portion 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, each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state, so that when the inner pin 4 revolves in the loose fitting hole 32, the inner pin 4 itself can rotate. is. Therefore, loss due to frictional resistance between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4 can be reduced without using an inner roller that is attached to the inner pin 4 and rotatable about the inner pin 4 . Therefore, the gear device 1 according to this basic configuration does not require an inner roller, which is advantageous in that it can be easily miniaturized. Moreover, since at least a part of each of the plurality of inner pins 4 is arranged at the same position as the bearing member 6 in the axial direction of the bearing member 6, the dimension of the gear device 1 in the axial direction of the bearing member 6 can be reduced. can be done. That is, compared to a structure in which the bearing member 6 and the inner pin 4 are aligned (opposed) in the axial direction of the bearing member 6, the gear device 1 according to the present basic configuration can reduce the dimension of the gear device 1 in the axial direction. , can contribute to further downsizing (thinning) of the gear device 1 .

Furthermore, if the dimensions of the planetary gear 3 are the same as those of the first related technology, for example, the number of inner pins 4 may be increased to smoothen transmission of rotation, compared to the first related technology. It is also possible to increase the strength by thickening the inner pin 4 .

Further, in this type of gear device 1, it is necessary for the inner pins 4 to revolve inside the loose fitting holes 32 of the planetary gears 3. The carrier integrated with the device) may be held alone. According to the second related technique, it is difficult to improve the accuracy of the centering of the plurality of inner pins 4, and poor centering may lead to problems such as generation of vibration and reduction in transmission efficiency. In other words, the plurality of inner pins 4 rotate relative to the internal gear 2 while revolving in the loose fitting holes 32 , thereby transmitting the rotation component of the planetary gear 3 to the inner ring 61 of the bearing member 6 . do. At this time, if the centering accuracy of the plurality of inner pins 4 is insufficient and the rotating shafts of the plurality of inner pins 4 are shifted or tilted with respect to the rotating shaft of the inner ring 61, poor centering occurs. , the occurrence of vibration, and a decrease in transmission efficiency. With the following configuration, the gear device 1 according to the present basic configuration can provide an internal meshing planetary gear device 1 that is less susceptible to problems caused by poor centering of the plurality of inner pins 4 .

That is, the gear device 1 according to this basic configuration includes an internal gear 2, planetary gears 3, a plurality of inner pins 4, and a support 8, as shown in FIGS. The internal gear 2 has an annular gear body 22 and a plurality of outer pins 23 . A plurality of outer pins 23 are held on the inner peripheral surface 221 of the gear body 22 in a rotatable state and constitute the inner teeth 21 . The planetary gear 3 has external teeth 31 that partially mesh with the internal teeth 21 . The plurality of inner pins 4 are inserted into the plurality of loose fitting holes 32 formed in the planetary gear 3 and rotate relatively to the gear body 22 while revolving inside the loose fitting holes 32 . The support 8 is annular and supports a plurality of inner pins 4 . Here, the support 8 is positionally regulated by bringing the outer peripheral surface 81 into contact with the plurality of outer pins 23 .

According to this aspect, since the plurality of inner pins 4 are supported by the annular support member 8, the plurality of inner pins 4 are bundled by the support member 8, and relative displacement of the plurality of inner pins 4 is prevented. and tilt are suppressed. Moreover, the outer peripheral surface 81 of the support 8 is in contact with the plurality of outer pins 23, thereby restricting the position of the support 8. As shown in FIG. In short, the support 8 is centered by the plurality of outer pins 23, and as a result, the plurality of inner pins 4 supported by the support 8 are also centered by the plurality of outer pins 23. . Therefore, according to the gear device 1 according to the basic configuration, there is an advantage that it is easy to improve the accuracy of the centering of the plurality of inner pins 4, and that problems due to poor centering of the plurality of inner pins 4 are less likely to occur. .

Further, the gear device 1 according to this basic configuration constitutes an actuator 100 together with a drive source 101, as shown in FIG. In other words, the actuator 100 according to this basic configuration includes the gear device 1 and the drive source 101 . A drive source 101 generates a drive force for swinging the planetary gear 3 . Specifically, the drive source 101 causes the planetary gear 3 to oscillate by rotating the eccentric shaft 7 around the rotation axis Ax1.

(2) Definition “Annular” in the present disclosure means a ring-like shape that forms a space (area) surrounded inside at least in plan view, and a perfect circle and a certain circle in plan view The shape is not limited to an annular shape, and 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 the "annular shape" as long as the peripheral wall is annular.

The term “loose fitting” as used in the present disclosure means fitting with play (gap), and the loose fitting hole 32 is a hole into which the inner pin 4 is loosely fitted. That is, the inner pin 4 is inserted into the loose fitting hole 32 with a spatial allowance (gap) secured between the inner pin 4 and the inner peripheral surface 321 of the loose fitting hole 32 . In other words, at least the diameter of the portion of the inner pin 4 that is inserted into the loose fitting hole 32 is smaller (thinner) than the diameter of the loose fitting hole 32 . Therefore, the inner pin 4 is movable in the loose fitting hole 32 while being inserted into the loose fitting hole 32 , that is, relatively movable with respect to the center of the loose fitting hole 32 . Therefore, the inner pin 4 can revolve inside the loose fitting hole 32 . However, it is not essential to secure a gap as a cavity between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4. For example, even if this gap is filled with fluid such as liquid, good.

"Revolution" as used in 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. will move along an orbit centered on Therefore, for example, when an object rotates around an eccentric axis parallel to the central axis passing through the center (center of gravity) of the object, the object revolves around the eccentric axis as the axis of rotation. . As an example, the inner pin 4 revolves inside the loose fitting hole 32 so as to revolve around a rotation axis passing through the center of the loose fitting hole 32 .

Further, in the present disclosure, one side of the rotation axis Ax1 (the left side in FIG. 3) may be referred to as the "input side" and the other side of the rotation axis Ax1 (the right side in FIG. 3) may be referred to as the "output side." In the example of FIG. 3, rotation is given to the rotating body (eccentric inner ring 51) from the "input side" of the rotation axis Ax1, and rotation of the plurality of inner pins 4 (inner ring 61) is given from the "output side" of the rotation axis Ax1. taken out. However, the terms "input side" and "output side" are merely labels attached for explanation, and are not meant to limit the positional relationship between the input and the output as viewed from the gear device 1 .

A "rotational axis" as used in the present disclosure means a virtual axis (straight line) that is the center of rotational motion of a rotating body. That is, the rotation axis Ax1 is a virtual axis with no substance. The eccentric inner ring 51 rotates about the rotation axis Ax1.

"Internal teeth" and "external teeth" as used in the present disclosure each mean a set (group) of a plurality of "teeth" rather than a single "tooth". That is, the internal tooth 21 of the internal gear 2 is a set of a plurality of teeth arranged on the inner peripheral surface 221 of the internal gear 2 (gear body 22). Similarly, the external teeth 31 of the planetary gear 3 are a set of teeth arranged on the outer peripheral surface of the planetary gear 3 .

(3) Configuration Hereinafter, the detailed configuration of the internal meshing planetary gear device 1 according to the present basic configuration will be described with reference to FIGS. 1 to 8B.

FIG. 1 is a perspective view showing a schematic configuration of an actuator 100 including a gear device 1. FIG. FIG. 1 schematically shows the drive source 101 . FIG. 2 is a schematic exploded perspective view of the gear device 1 viewed from the output side of the rotating shaft Ax1. FIG. 3 is a schematic cross-sectional view of the gear device 1. FIG. 4 is a cross-sectional view taken along line A1-A1 of FIG. 3. FIG. However, in FIG. 4, parts other than the eccentric shaft 7 are omitted from hatching even in cross sections. 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 alone. 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 8 alone.

(3.1) Overall Configuration A gear device 1 according to this basic configuration includes an internal gear 2, a planetary gear 3, a plurality of inner pins 4, and an eccentric bearing 5, as shown in FIGS. , a bearing member 6 , an eccentric shaft 7 and a support 8 . Moreover, in this basic configuration, the gear device 1 further includes a first bearing 91 , a second bearing 92 and a case 10 . In this basic configuration, the materials of the internal gear 2, the planetary gear 3, the plurality of inner pins 4, the eccentric bearing 5, the bearing member 6, the eccentric shaft 7, the support 8, etc., which are the constituent elements of the gear device 1, are stainless steel. , cast iron, carbon steel for machine structural use, chromium molybdenum steel, phosphor bronze or aluminum bronze. The metal referred to here includes a metal subjected to surface treatment such as nitriding.

Further, in this basic configuration, as an example of the gear device 1, an internal planetary gear device using a trochoidal tooth profile is exemplified. That is, the gear device 1 according to this basic configuration includes the internal planetary gear 3 having a trochoidal curved tooth profile.

Further, in this basic configuration, 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 fixed member such as the case 10 together with the outer ring 62 of the bearing member 6 . As a result, as the internal gear 2 and the planetary gear 3 rotate relative to each other, the planetary gear 3 rotates relative to the fixed member (case 10, etc.).

Furthermore, in the present basic configuration, when the gear device 1 is used for the actuator 100, a rotational force as an input is applied to the eccentric shaft 7, so that the output shaft integrated with the inner ring 61 of the bearing member 6 rotates as an output. power is extracted. That is, the gear device 1 operates with the rotation of the eccentric shaft 7 as input rotation and the rotation of the output shaft integrated with the inner ring 61 as output rotation. As a result, in the gear device 1, an output rotation that is reduced at a relatively high speed reduction ratio is obtained with respect to the input rotation.

The drive source 101 is a power generation source such as a motor (electric motor). Power generated by the drive source 101 is transmitted to the eccentric shaft 7 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. This allows the drive source 101 to rotate the eccentric shaft 7 .

Furthermore, in the gear device 1 according to this basic configuration, as shown in FIG. 3, the input-side rotation axis Ax1 and the output-side rotation axis Ax1 are on the same straight line. In other words, the input-side rotation axis Ax1 and the output-side rotation axis Ax1 are coaxial. Here, the input-side rotation axis Ax1 is the rotation center of the eccentric shaft 7 to which the input rotation is applied, and the output-side rotation axis Ax1 is the rotation center of the inner ring 61 (and the output shaft) that produces the output rotation. . In other words, in the gear device 1, the output rotation is coaxially reduced with respect to the input rotation with a relatively high reduction ratio.

The internal gear 2 is an annular component having internal teeth 21, as shown in FIG. In this basic configuration, the internal gear 2 has an annular shape in which at least the inner peripheral surface is a perfect circle in plan view. Internal teeth 21 are formed on the inner peripheral surface of the annular internal gear 2 along the circumferential direction of the internal gear 2 . The plurality of teeth forming the internal gear 21 are all of the same shape, and are provided at equal pitches over the entire circumferential direction of the internal peripheral surface of the internal gear 2 . That is, the pitch circle of the internal 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. Moreover, the internal gear 2 has a predetermined thickness in the direction of the rotation axis Ax1. All tooth traces of the internal teeth 21 are parallel to the rotation axis Ax1. The dimension of the internal tooth 21 in the tooth trace direction is slightly smaller than the thickness direction of the internal gear 2 .

Here, the internal gear 2 has an annular (annular) gear main body 22 and a plurality of outer pins 23 as described above. A plurality of outer pins 23 are held on the inner peripheral surface 221 of the gear body 22 in a rotatable state, and constitute the inner teeth 21 . In other words, the plurality of outer pins 23 function as a plurality of teeth forming the inner teeth 21 respectively. Specifically, as shown in FIG. 2, the inner peripheral surface 221 of the gear body 22 is formed with a plurality of grooves over the entire circumference. All of the plurality of grooves have the same shape and are provided at equal pitches. The plurality of grooves are all parallel to the rotation axis Ax1 and are formed over the entire length of the gear body 22 in the thickness direction. A plurality of outer pins 23 are combined with the gear body 22 so as to fit in the plurality of grooves. Each of the plurality of outer pins 23 is held in the groove in a rotatable state. Further, the gear body 22 is fixed to the case 10 (together with the outer ring 62). Therefore, a plurality of fixing holes 222 for fixing are formed in the gear body 22 .

The planetary gear 3 is an annular component having external teeth 31, as shown in FIG. In this basic configuration, the planetary gear 3 has an annular shape with at least an outer peripheral surface that is a perfect circle in a plan view. External teeth 31 are formed along the circumferential direction of the planetary gear 3 on the outer peripheral surface of the annular planetary gear 3 . The plurality of teeth forming the external teeth 31 are all of the same shape, and are provided at equal pitches over the entire peripheral surface of the planetary gear 3 in the circumferential direction. 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 located at a position displaced from the rotation axis Ax1 by a distance ΔL (see FIG. 4). Also, the planetary gear 3 has a predetermined thickness in the direction of the rotation axis Ax1. Each of the external teeth 31 is formed over the entire length of the planetary gear 3 in the thickness direction. All of the tooth traces of the external teeth 31 are parallel to the rotation axis Ax1. In the planetary gear 3, unlike the internal gear 2, the external teeth 31 are integrally formed with the main body of the planetary gear 3 by one metal member.

Here, 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 a circular opening 33 . The opening 33 is a hole penetrating through the planetary gear 3 along the thickness direction. In plan view, the center of the opening 33 and the center of the planetary gear 3 are aligned, and the inner peripheral surface of the opening 33 (the inner peripheral surface of the planetary gear 3) and the pitch circle of the external teeth 31 are concentric. . The eccentric bearing 5 is accommodated in the opening 33 of the planetary gear 3 . Further, the eccentric shaft 7 is inserted into (the eccentric inner ring 51 of) the eccentric bearing 5 , so that the eccentric bearing 5 and the eccentric shaft 7 are combined with the planetary gear 3 . When the eccentric shaft 7 rotates in a state where the planetary gear 3 is combined with the eccentric body bearing 5 and the eccentric shaft 7, the planetary gear 3 oscillates around the rotation axis Ax1.

The planetary gear 3 configured in this way is arranged inside the internal gear 2 . In plan view, the planetary gear 3 is formed to be one size smaller than the internal gear 2, and the planetary gear 3 can oscillate inside the internal gear 2 while being combined with the internal gear 2. Become. Here, external teeth 31 are formed on the outer peripheral surface of the planetary gear 3 and internal teeth 21 are formed on the inner peripheral surface of the internal gear 2 . Therefore, when the planetary gear 3 is arranged inside the internal gear 2, the external teeth 31 and the internal teeth 21 face each other.

Furthermore, the pitch circle of the external teeth 31 is one size smaller than the pitch circle of the internal teeth 21 . In the state in which the planetary gear 3 is inscribed in the internal gear 2, the center C1 of the pitch circle of the external teeth 31 is positioned a distance ΔL (see FIG. 4) from the center of the pitch circle of the internal teeth 21 (rotational axis Ax1). in a misaligned position. Therefore, the external teeth 31 and the internal teeth 21 are at least partially opposed to each other with a gap therebetween, and the entire circumferential direction does not mesh with each other. However, since the planetary gear 3 oscillates (revolves) around the rotation axis Ax1 inside the internal gear 2, the external teeth 31 and the internal teeth 21 partially mesh with each other. In other words, as the planetary gear 3 oscillates around the rotation axis Ax1, some of the teeth that form the external teeth 31 shift to the plurality of teeth that form the internal teeth 21, as shown in FIG. It will mesh with some of the teeth. As a result, in the gear device 1 , it is possible to mesh a portion of the external teeth 31 with a portion of the internal teeth 21 .

Here, the number of teeth of the internal teeth 21 of the internal gear 2 is greater 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 configuration, 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 internal teeth 21) of the internal gear 2. The difference in the number of teeth between the planetary gear 3 and the internal gear 2 defines the reduction ratio of the output rotation to the input rotation in the gear device 1 .

Further, in this basic configuration, as an example, the thickness of the planetary gear 3 is smaller than the thickness of the gear main body 22 in the internal gear 2 . Furthermore, the dimension of the external teeth 31 in the tooth trace direction (the direction parallel to the rotation axis Ax1) is smaller than the dimension of the internal teeth 21 in the tooth trace direction (the direction parallel to the rotation axis Ax1). In other words, the external teeth 31 fit within the range of the tooth traces of the internal teeth 21 in the direction parallel to the rotation axis Ax1.

In this basic configuration, 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, the planetary gear 3 is formed with a plurality of loose fitting holes 32 for inserting the plurality of inner pins 4 . The loose fitting holes 32 are provided in the same number as the inner pins 4, and in this basic configuration, as an example, 18 loose fitting holes 32 and 18 inner pins 4 are provided. Each of the plurality of loose fitting holes 32 is a hole that is circularly open and penetrates through the planetary gear 3 along the thickness direction. A plurality of (here, 18) loose fitting holes 32 are arranged at equal intervals in the circumferential direction on a virtual circle concentric with the opening 33 .

The plurality of inner pins 4 are components that connect the planetary gear 3 and the inner ring 61 of the bearing member 6 . Each of the plurality of inner pins 4 is formed in a cylindrical shape. The diameter and length of the plurality of inner pins 4 are common to the plurality of inner pins 4 . The diameter of the inner pin 4 is one size smaller than the diameter of the loose fitting hole 32 . As a result, the inner pin 4 is inserted into the loose fitting hole 32 while securing a spatial margin (clearance) between itself and the inner peripheral surface 321 of the loose fitting hole 32 (see FIG. 4).

The bearing member 6 has an outer ring 62 and an inner ring 61 and is a part for outputting the output of the gear device 1 as 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 .

Both the outer ring 62 and the inner ring 61 are annular parts, as shown in FIGS. 6A and 6B. Both the outer ring 62 and the inner ring 61 have annular shapes that are perfect circles in a plan view. The inner ring 61 is one size 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 configuration, 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 circularly and penetrates the inner ring 61 along 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 equal to or larger than the diameter of the inner pin 4 and smaller than the diameter of the loose fitting hole 32 .

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

The outer ring 62 is fixed to a fixed member such as the case 10 together with the gear body 22 of the internal gear 2 . Therefore, the outer ring 62 is formed with a plurality of through holes 621 for fixing. Specifically, as shown in FIG. 3, the outer ring 62 and the case 10 hold the gear body 22 between the outer ring 62 and the fixing screw (bolt) passing through the through hole 621 and the fixing hole 222 of the gear body 22 . ) 60 to the case 10 .

A plurality of rolling elements 63 are arranged in a gap between the outer ring 62 and the inner ring 61 . A plurality of rolling elements 63 are arranged side by side in the circumferential direction of the outer ring 62 . The plurality of rolling elements 63 are all metal parts having the same shape, and are provided at equal pitches over the entire circumference of the outer ring 62 .

In this basic configuration, as an example, the bearing member 6 is a cross roller bearing. That is, the bearing member 6 has cylindrical rollers as the rolling elements 63 . 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, the pair of rolling elements 63 adjacent to each other in the circumferential direction of the inner ring 61 are arranged so that their axial directions are perpendicular to each other. The bearing member 6 made of such a cross roller bearing is likely to receive all of a radial load, a thrust load (a direction along the rotation axis Ax1), and a bending force (bending moment load) with respect to the rotation axis Ax1. . Moreover, one bearing member 6 can withstand these three types of loads, and the required rigidity can be ensured.

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

In this basic configuration, the axial center portion 71 and the eccentric portion 72 are integrally formed of one metal member, thereby realizing a 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 planetary gear 3 is combined with the eccentric body bearing 5 and the eccentric shaft 7, the planetary gear 3 swings around the rotation axis Ax1.

Furthermore, the eccentric shaft 7 has a through hole 73 that penetrates the shaft center portion 71 in the axial direction (longitudinal direction). The through holes 73 are circularly open on both axial end surfaces of the axial center portion 71 . The center (central axis) of the through hole 73 coincides with the rotation axis Ax1. Cables such as power lines and signal lines can be passed through the through holes 73, for example.

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

The eccentric body bearing 5 has an eccentric body outer ring 52 and an eccentric body inner ring 51, absorbs the rotation component of the rotation of the eccentric shaft 7, and rotates the eccentric shaft 7 excluding the rotation component of the eccentric shaft 7, that is, the eccentricity. It is a component for transmitting only the oscillation component (orbital component) of the shaft 7 to the planetary gear 3 . The eccentric body bearing 5 has a plurality of rolling elements 53 (see FIG. 3) in addition to the eccentric body outer ring 52 and the eccentric body inner ring 51 .

Both the eccentric outer ring 52 and the eccentric inner ring 51 are annular parts. Both the outer ring 52 of the eccentric body and the inner ring 51 of the eccentric body have annular shapes that are perfect circles in a plan view. The eccentric inner ring 51 is one size 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 .

A plurality of rolling elements 53 are arranged in a gap between the eccentric outer ring 52 and the eccentric inner ring 51 . A plurality of rolling elements 53 are arranged side by side in the circumferential direction of the eccentric outer ring 52 . The plurality of rolling elements 53 are all metal parts having the same shape, and are provided at equal pitches over the entire circumference of the eccentric outer ring 52 . In this basic configuration, as an example, the eccentric body bearing 5 is a deep groove ball bearing using balls as the rolling elements 53 .

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

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

When the eccentric shaft 7 rotates in a state where the eccentric bearing 5 and the eccentric shaft 7 are combined with the planetary gear 3, the eccentric inner ring 51 rotates around the rotation axis Ax1 shifted from the center C1 of the eccentric inner ring 51. The wheel 51 rotates (eccentric motion). At this time, the rotation component of the eccentric shaft 7 is absorbed by the eccentric bearing 5 . Therefore, the eccentric bearing 5 transmits to the planetary gear 3 only the rotation of the eccentric shaft 7 excluding the rotation component of the eccentric shaft 7 , that is, only the oscillating component (orbital component) of the eccentric shaft 7 . Therefore, when the eccentric shaft 7 rotates in a state where the planetary gear 3 is combined with the eccentric body bearing 5 and the eccentric shaft 7, the planetary gear 3 swings around the rotation axis Ax1.

8A and 8B, the support 8 is a component that is formed in an annular shape and supports the plurality of inner pins 4. As shown in FIGS. The support 8 has a plurality of support holes 82 into which the plurality of inner pins 4 are respectively inserted. The support holes 82 are provided in the same number as the inner pins 4, and in this basic configuration, 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 circularly and penetrates the support 8 along 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 8 . The diameter of the support hole 82 is equal to or larger than the diameter of the inner pin 4 and smaller than the diameter of the loose fitting hole 32 . In this basic configuration, 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 .

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

The first bearing 91 and the second bearing 92 are mounted on the axial center portion 71 of the eccentric shaft 7, respectively. Specifically, as shown in FIG. 3, the first bearing 91 and the second bearing 92 are arranged on both sides of the eccentric portion 72 in the axial center portion 71 so as to sandwich the eccentric portion 72 in the direction parallel to the rotation axis Ax1. be worn. The first bearing 91 is arranged on the input side of the rotation axis Ax1 when viewed from the eccentric portion 72 . The second bearing 92 is arranged on the output side of the rotation axis Ax1 when viewed from the eccentric portion 72 . The first bearing 91 rotatably holds the eccentric shaft 7 with respect to the case 10 . The second bearing 92 rotatably holds the eccentric shaft 7 with respect to the inner ring 61 of the bearing member 6 . As a result, the axial center portion 71 of the eccentric shaft 7 is rotatably held at two points on both sides of the eccentric portion 72 in the direction parallel to the rotation axis Ax1.

The case 10 is cylindrical and has a flange portion 11 on the output side of the rotation axis Ax1. A plurality of installation holes 111 for fixing the case 10 itself are formed in the flange portion 11 . A bearing hole 12 is formed in the end face of the case 10 on the output side of the rotating shaft Ax1. The bearing hole 12 is open in a circular shape. The first bearing 91 is attached to the case 10 by fitting the first bearing 91 into the bearing hole 12 .

A plurality of screw holes 13 are formed around the bearing hole 12 on the output side end face of the rotating shaft Ax1 in the case 10 . A plurality of screw holes 13 are used to fix the gear body 22 of the internal gear 2 and the outer ring 62 of the bearing member 6 to the case 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 tightened into the screw hole 13 , thereby fixing the gear body 22 and the outer ring 62 to the case 10 . be done.

Further, the gear device 1 according to this basic configuration further includes a plurality of oil seals 14, 15, 16, etc., as shown in FIG. The oil seal 14 is attached to the end of the eccentric shaft 7 on the input side of the rotating shaft Ax1, and closes the gap between the case 10 and the eccentric shaft 7 (shaft center portion 71). The oil seal 15 is attached to the end of the eccentric shaft 7 on the output side of the rotating shaft Ax1, and closes the gap between the inner ring 61 and the eccentric shaft 7 (shaft center portion 71). The oil seal 16 is attached to the end surface of the bearing member 6 on the output side of the rotating shaft Ax1 and closes the gap between the inner ring 61 and the outer ring 62 . A space sealed by the plurality of oil seals 14, 15, 16 constitutes a lubricant holding space 17 (see FIG. 9). Lubricant holding space 17 includes a space between inner ring 61 and outer ring 62 of bearing member 6 . Furthermore, the plurality of outer pins 23, the planetary gear 3, the eccentric bearing 5, the support 8, the first bearing 91, the second bearing 92, and the like are accommodated in the lubricant holding space 17. As shown in FIG.

A lubricant is injected into the lubricant holding space 17 . The lubricant is liquid and can flow within the lubricant holding space 17 . Therefore, when the gear device 1 is used, for example, the lubricant enters the meshing portions between the internal teeth 21 formed by the plurality of external pins 23 and the external teeth 31 of the planetary gears 3 . "Liquid" as used in the present disclosure includes liquid or gel substances. The term "gel state" as used herein means a state having properties intermediate between those of a liquid and a solid, and includes a state of colloid consisting of two phases, a liquid phase and a solid phase. For example, there is a state called gel or sol, such as an emulsion in which the dispersion medium is a liquid phase and the dispersoid is a liquid phase, or a suspension in which the dispersoid is a solid phase. Included in "gel-like". The state in which the dispersion medium is a solid phase and the dispersoid is a liquid phase is also included in the “gel state”. As an example in this basic configuration, the lubricant is liquid lubricating oil (oil).

In the gear device 1 configured as described above, a rotational force as an input is applied to the eccentric shaft 7, and the eccentric shaft 7 rotates about the rotation axis Ax1, causing the planetary gears 3 to oscillate about the rotation axis Ax1. (revolve). At this time, the planetary gear 3 is inscribed with the internal gear 2 inside the internal gear 2 and oscillates with a portion of the external teeth 31 meshing with a portion of the internal teeth 21 . 21 and the external teeth 31 move in the circumferential direction of the internal gear 2 . As a result, relative rotation occurs between the two gears (the internal gear 2 and the planetary gear 3) according to the difference in the number of teeth between the planetary gear 3 and the internal gear 2. Rotation (rotational component) of the planetary gear 3 excluding the oscillation component (revolution component) of the planetary gear 3 is transmitted to the inner ring 61 of the bearing member 6 by the plurality of inner pins 4 . As a result, from the output shaft integrated with the inner ring 61, rotational output reduced at a relatively high speed reduction ratio can be obtained in accordance with the difference in the number of teeth between the two gears.

By the way, in the gear device 1 according to the present embodiment, as described above, the difference in the number of teeth between the internal gear 2 and the planetary gear 3 defines the reduction ratio of the output rotation to the input rotation in the gear device 1. become. 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 expressed by the following equation 1.

R1=V2/(V1-V2) (Formula 1)
In short, the smaller the tooth number difference (V1-V2) between the internal gear 2 and the planetary gear 3, the larger the reduction ratio R1. As an example, the number of teeth V1 of the internal gear 2 is "52", the number of teeth V2 of the planetary gear 3 is "51", and the difference between the number of teeth (V1-V2) is "1". The speed reduction ratio R1 becomes "51". In this case, when the eccentric shaft 7 rotates clockwise around the rotation axis Ax1 once (360 degrees) as viewed from the input side of the rotation axis Ax1, the inner ring 61 has a tooth difference of "1" around the rotation axis Ax1. counterclockwise by 100 degrees (ie, about 7.06 degrees).

According to the gear device 1 according to this basic configuration, such a high reduction ratio R1 can be realized by a combination of one-stage gears (the internal gear 2 and the planetary gears 3).

Moreover, the gear device 1 may include at least the internal gear 2, the planetary gear 3, the plurality of inner pins 4, the bearing member 6, and the support 8. For example, a spline bush or the like may be provided. It may be further provided as a component.

By the way, when the input rotation on the high-speed rotation side accompanies eccentric motion, as in the gear device 1 according to this basic configuration, if the weight of the rotating body rotating at high speed is not balanced, it may lead to vibration or the like. Therefore, a counterweight or the like may be used to balance the weight. 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 moves eccentrically at high speed, it is possible to balance the weight of the rotating body with respect to the rotation axis Ax1. preferable. In this basic configuration, as shown in FIGS. 3 and 4, a space 75 is provided in a part of the eccentric portion 72 of the eccentric shaft 7 to balance the weight of the rotating body with respect to the rotating shaft Ax1.

In short, in this basic configuration, a part of the rotating body (here, the eccentric shaft 7) is lightened instead of adding a counterweight or the like to reduce the weight, thereby balancing the weight of the rotating body with respect to the rotation axis Ax1. I'm taking That is, the gear device 1 according to this basic configuration includes the eccentric body bearing 5 that is housed in the opening 33 formed in the planetary gear 3 and causes the planetary gear 3 to oscillate. The eccentric bearing 5 has an eccentric outer ring 52 and an eccentric inner ring 51 arranged inside the eccentric outer ring 52 . A rotating body composed of at least one of the eccentric inner ring 51 and a member that rotates together with the eccentric inner ring 51 has a gap 75 in a part of the eccentric outer ring 52 on the center C1 side when viewed from the rotation axis Ax1 of the eccentric inner ring 51. . In this basic configuration, 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 gap 75 is located on the center C1 side when viewed from the rotation axis Ax1. works.

More specifically, the gap 75 includes a recess formed in the inner peripheral surface of the through hole 73 passing through the rotor along the rotation axis Ax1 of the eccentric inner ring 51 . That is, in this basic configuration, since the rotating body is the eccentric shaft 7 , the concave portion formed in the inner peripheral surface of the through hole 73 passing through the eccentric shaft 7 along the rotation axis Ax1 functions as the air gap 75 . In this manner, by using the concave portion formed on the inner peripheral surface of the through hole 73 as the air gap 75, it is possible to balance the weight of the rotor without changing the appearance.

(3.2) Rotation Structure of Inner Pin Next, the rotation structure of the inner pin 4 of the gear device 1 according to the basic configuration will be described in more detail with reference to FIG. FIG. 9 is an enlarged view of area Z1 in FIG.

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

Here, since the diameter of the inner pin 4 is one size smaller than the diameter of the loose fitting hole 32, a gap is secured between the inner pin 4 and the inner peripheral surface 321 of the loose fitting hole 32, and the inner pin 4 is , is movable within the loosely fitting hole 32 , that is, relatively movable with respect to the center of the loosely fitting hole 32 . On the other hand, the diameter of the holding hole 611 is larger than the diameter of the inner pin 4, but smaller than the diameter of the loose fitting hole 32. As shown in FIG. In this basic configuration, 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 movement of the inner pin 4 relative to the center of the holding hole 611 is prohibited. Therefore, the inner pin 4 is held in a state in which it can revolve inside the loose fitting hole 32 in the planetary gear 3 , and is held in a state in which it cannot revolve inside the holding hole 611 with respect to the inner ring 61 . As a result, the oscillating component of the planetary gear 3 , that is, the revolution component of the planetary gear 3 is absorbed by the loose fit between the loose fitting hole 32 and the inner pin 4 , and the planetary gear The rotation (rotational component) of the planetary gear 3 excluding the oscillation component (revolution component) of 3 is transmitted.

By the way, in this basic configuration, the diameter of the inner pin 4 is slightly larger than that of the holding hole 611 , so that the inner pin 4 is prohibited from revolving inside the holding hole 611 while being inserted into the holding hole 611 . However, rotation within the holding hole 611 is possible. In other words, even when the inner pin 4 is inserted into the holding hole 611 , it is not press-fitted into the holding hole 611 , so it can rotate within the holding hole 611 . As described above, in the gear device 1 according to the present basic configuration, each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state. , the inner pin 4 itself can rotate.

In short, in this basic configuration, the inner pin 4 is held with respect to the planetary gear 3 so as to be able to both revolve and rotate within the loose fitting hole 32 , and with respect to the inner ring 61 within the holding hole 611 . It is held in a state where only rotation at is possible. In other words, the plurality of inner pins 4 are capable of rotating (revolving) around the rotation axis Ax1 and revolving within the plurality of loose fitting holes 32 in a state in which their rotation is not constrained (rotational state). is. 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 revolve and rotate in the loose fitting holes 32 and rotate in the holding holes 611 . can rotate. Therefore, when the inner pin 4 revolves in the loose fitting hole 32 , the inner pin 4 is in a rotatable state, so it rolls on the inner peripheral surface 321 of the loose fitting hole 32 . In other words, the inner pin 4 revolves within the loosely fitting hole 32 while rolling on the inner peripheral surface 321 of the loosely fitting hole 32 , so that the inner pin 4 and the inner peripheral surface 321 of the loosely fitting hole 32 . Loss due to frictional resistance is less likely to occur.

As described above, in the configuration according to the present basic configuration, it is possible to omit the inner roller since loss due to frictional resistance between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4 is unlikely to occur in the first place. Therefore, in this basic configuration, each of the plurality of inner pins 4 is configured to directly contact the inner peripheral surface 321 of the loose fitting hole 32 . That is, in this basic configuration, the inner pin 4 without the inner roller is inserted into the loose fitting hole 32 so that the inner pin 4 directly contacts the inner peripheral surface 321 of the loose fitting hole 32 . . As a result, the inner roller can be omitted and the diameter of the loose fitting hole 32 can be kept relatively small, so that the size of the planetary gear 3 can be reduced (especially, the diameter can be reduced). Easier to plot. If the dimensions of the planetary gear 3 are to be constant, for example, the number of inner pins 4 may be increased to smoothen transmission of rotation, or the inner pins 4 may be made thicker than in the first related art. It is also possible to improve the strength by Furthermore, the number of parts can be reduced by the number of inner rollers, and the cost of the gear device 1 can be reduced.

Further, in the gear device 1 according to the basic configuration, at least a part of each of the plurality of inner pins 4 is arranged at the same position as the bearing member 6 in the axial direction of the bearing member 6 . That is, as shown in FIG. 9, at least a part of the inner pin 4 is arranged at the same position as the bearing member 6 in the direction parallel to the rotation axis Ax1. In other words, at least part of the inner pin 4 is positioned between both end faces of the bearing member 6 in the direction parallel to the rotation axis Ax1. Furthermore, in other words, each of the plurality of inner pins 4 is at least partially arranged inside the outer ring 62 of the bearing member 6 . In this basic configuration, the end of the inner pin 4 on the output side of the rotation axis Ax1 is at the same position as the bearing member 6 in the direction parallel to the rotation axis Ax1. In short, since the end of the inner pin 4 on the output side of the rotation axis Ax1 is inserted into the holding hole 611 formed in the inner ring 61 of the bearing member 6, at least the end is aligned with the shaft of the bearing member 6. It is arranged at the same position as the bearing member 6 in the direction.

In this manner, at least 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, so that the dimension of the gear device 1 in the direction parallel to the rotation axis Ax1 is can be kept small. That is, compared to a configuration in which the bearing member 6 and the inner pin 4 are aligned (faced) in the axial direction of the bearing member 6, in the gear device 1 according to this basic configuration, the gear device 1 can be reduced, which can contribute to further miniaturization (thinness) of the gear device 1 .

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

Further, in this basic configuration, the following configuration is adopted so that the inner pin 4 rotates smoothly with respect to the inner ring 61 . That is, by interposing a lubricant (lubricating oil) between the inner peripheral surface of the holding hole 611 formed in the inner ring 61 and the inner pin 4, the rotation of the inner pin 4 is smoothed. Especially in this basic configuration, since the lubricant holding space 17 into which the lubricant is injected exists between the inner ring 61 and the outer ring 62, the lubricant in the lubricant holding space 17 is used to move the inner pin 4. Promote smooth rotation.

In this basic configuration, as shown in FIG. 9 , 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 paths 64 . A plurality of connecting passages 64 connect between 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 part of the inner peripheral surface of the holding hole 611 corresponding to the rolling element 63 . The connecting path 64 is a hole penetrating between the bottom surface of the recessed portion (groove) accommodating the rolling elements 63 on the surface of the inner ring 61 facing the outer ring 62 and the inner peripheral surface of the holding hole 611 . In other words, the opening surface of the connecting passage 64 on the side of the lubricant holding space 17 is arranged at a position facing (facing) the rolling elements 63 of the bearing member 6 . The lubricant holding space 17 and the holding hole 611 are spatially connected via the connecting path 64 as described above.

According to the configuration described above, 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 . become. That is, when the bearing member 6 operates and the rolling elements 63 rotate, the rolling elements 63 function as a pump, and the lubricant in the lubricant holding space 17 can be sent to the holding hole 611 via the connecting passage 64. is. In particular, since the opening surface of the connecting passage 64 on the side of the lubricant holding space 17 is positioned to face (oppose) the rolling elements 63 of the bearing member 6, the rolling elements 63 can efficiently function as a pump when the rolling elements 63 rotate. effectively. As a result, the lubricant intervenes between the inner peripheral surface of the holding hole 611 and the inner pin 4 , and smooth rotation of the inner pin 4 with respect to the inner ring 61 can be achieved.

(3.3) Support Next, the configuration of the support 8 of the gear device 1 according to this basic configuration will be described in more detail with reference to FIG. 10 is a cross-sectional view taken along the line B1-B1 of FIG. 3. FIG. However, in FIG. 10, parts other than the support 8 are omitted from hatching even in the cross section. Moreover, in FIG. 10, only the internal gear 2 and the support 8 are illustrated, and the illustration of other parts (the inner pin 4, etc.) is omitted. Furthermore, in FIG. 10, illustration of the inner peripheral surface 221 of the gear body 22 is omitted.

First, as a premise, the support 8 is a part that supports the plurality of inner pins 4 as described above. That is, by bundling the plurality of inner pins 4 , the support 8 distributes the load applied to the plurality of inner pins 4 when the rotation (rotational component) of the planetary gear 3 is transmitted to the inner ring 61 . Specifically, it has a plurality of support holes 82 into which the plurality of inner pins 4 are respectively inserted. In this basic configuration, 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 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 by both the inner ring 61 of the bearing member 6 and the support member 8 in a rotatable state.

Thus, the support 8 positions the plurality of inner pins 4 with respect to the support 8 both in the circumferential direction and in the radial direction. That is, by inserting the inner pin 4 into the support hole 82 of the support 8, movement in all directions within a plane orthogonal to the rotation axis Ax1 is restricted. Therefore, the inner pin 4 is positioned by the support 8 not only in the circumferential direction but also in the radial direction.

Here, the support 8 has an annular shape in which at least the outer peripheral surface 81 is a perfect circle in plan view. The position of the support 8 is restricted by bringing the outer peripheral surface 81 into contact with the plurality of outer pins 23 of the internal gear 2 . Since the plurality of outer pins 23 form the inner teeth 21 of the internal gear 2 , in other words, the position of the support 8 is restricted by bringing the outer peripheral surface 81 into contact with the inner teeth 21 . Here, the diameter of the outer peripheral surface 81 of the support 8 is the same as the diameter of the virtual circle (tip circle) passing through the tips of the internal teeth 21 in the internal gear 2 . Therefore, all of the plurality of outer pins 23 contact the outer peripheral surface 81 of the support 8 . Therefore, in a state where the support 8 is positionally regulated by the plurality of outer pins 23, the center of the support 8 is positionally regulated so as to overlap the center of the internal gear 2 (rotational axis Ax1). As a result, the support 8 is centered, and as a result, the plurality of inner pins 4 supported by the support 8 are also centered by the plurality of outer pins 23 .

In addition, the plurality of inner pins 4 rotate (revolve) around the rotation axis Ax<b>1 to transmit the rotation (rotation component) of the planetary gear 3 to the inner ring 61 . Therefore, the support 8 that supports 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 8 is centered by the plurality of outer pins 23, the support 8 rotates smoothly while the center of the support 8 is maintained on the rotation axis Ax1. Moreover, since the support 8 rotates with its outer peripheral surface 81 in contact with the plurality of outer pins 23 , each of the plurality of outer pins 23 rotates (rotates) as the support 8 rotates. Therefore, the support 8 constitutes a needle bearing (needle roller bearing) together with the internal gear 2 and rotates smoothly.

That is, the outer peripheral surface 81 of the support 8 rotates relatively to the gear body 22 together with the plurality of inner pins 4 while being in contact with the plurality of outer pins 23 . Therefore, if the gear body 22 of the internal gear 2 is regarded as an "outer ring" and the support 8 as an "inner ring", the plurality of outer pins 23 interposed therebetween function as "rollers". Thus, the support 8 constitutes a needle bearing together with the internal gear 2 (the gear body 22 and the plurality of outer pins 23), enabling smooth rotation.

Furthermore, since the support 8 sandwiches the plurality of outer pins 23 between itself and the gear body 22, the support 8 suppresses movement of the outer pins 23 away from the inner peripheral surface 221 of the gear body 22. It also functions as a "stopper". In other words, the plurality of outer pins 23 are sandwiched between the outer peripheral surface 81 of the support 8 and the inner peripheral surface 221 of the gear body 22, thereby suppressing floating from the inner peripheral surface 221 of the gear body 22. . In short, in this basic configuration, each of the plurality of outer pins 23 is restricted from moving away from the gear body 22 by contacting the outer peripheral surface 81 of the support 8 .

By the way, in this basic configuration, as shown in FIG. 9 , the support 8 is located on the opposite side of the inner ring 61 of the bearing member 6 with the planetary gear 3 interposed therebetween. That is, the support 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 configuration, as an example, the support 8 is positioned on the input side of the rotation axis Ax1 when viewed from the planetary gear 3, and the inner ring 61 is positioned on the output side of the rotation axis Ax1 when viewed from the planetary gear 3. Together with the inner ring 61, the support 8 supports both ends of the inner pin 4 in the longitudinal direction (direction parallel to the rotation axis Ax1). It is inserted through the hole 32 . In short, the gear device 1 according to this basic configuration has an outer ring 62 and an inner ring 61 arranged inside the outer ring 62, and the bearing member 6 supported so that the inner ring 61 can rotate relative to the outer ring 62. I have. The gear body 22 is fixed to the outer ring 62 . Here, the planetary gear 3 is positioned between the support 8 and the inner ring 61 in the axial direction of the support 8 .

According to this configuration, the support 8 and the inner ring 61 support both ends of the inner pin 4 in the longitudinal direction, so that the inner pin 4 is less likely to tilt. In particular, the plurality of inner pins 4 are likely to receive a bending force (bending moment load) with respect to the rotation axis Ax1. Further, in this basic configuration, the support 8 is sandwiched between the planetary gear 3 and the case 10 in the direction parallel to the rotation axis Ax1. As a result, the support 8 is restricted by the case 10 from moving toward the input side (left side in FIG. 9) of the rotation axis Ax1. As for the inner pin 4 that penetrates the support hole 82 of the support 8 and protrudes from the support 8 toward the input side of the rotation axis Ax1, the movement of the inner pin 4 to the input side (left side in FIG. 9) of the rotation axis Ax1 is caused by the case 10. regulated by

Further, in this basic configuration, the support 8 and the inner ring 61 contact both ends of the plurality of outer pins 23 . That is, as shown in FIG. 9, the support 8 contacts one end (the input side end of the rotation axis Ax1) of the outer pin 23 in the longitudinal direction (direction parallel to the rotation axis Ax1). The inner ring 61 contacts the other end (the end on the output side of the rotation axis Ax1) of the outer pin 23 in the longitudinal direction (direction parallel to the rotation axis Ax1). According to this configuration, the support 8 and the inner ring 61 are centered at both ends of the outer pin 23 in the longitudinal direction, so that the inner pin 4 is less likely to tilt. In particular, the plurality of inner pins 4 are likely to receive a bending force (bending moment load) with respect to the rotation axis Ax1.

Moreover, the plurality of outer pins 23 have a length equal to or greater than the thickness of the support 8 . In other words, in the direction parallel to the rotation axis Ax1, the support 8 fits within the range of the tooth traces of the internal teeth 21 . As a result, the outer peripheral surface 81 of the support 8 comes into contact with the plurality of outer pins 23 over the entire length of the inner tooth 21 in the tooth trace direction (direction parallel to the rotation axis Ax1). Therefore, problems such as "uneven wear", in which the outer peripheral surface 81 of the support 8 is partially worn, are less likely to occur.

Further, in this basic configuration, the outer peripheral surface 81 of the support 8 has a smaller surface roughness than the surface adjacent to the outer peripheral surface 81 of the support 8 . That is, the surface roughness of the outer peripheral surface 81 is smaller than that of both end surfaces of the support 8 in the axial direction (thickness direction). "Surface roughness" as used in the present disclosure means the degree of roughness of the surface of an object. In this basic configuration, as an example, the surface roughness is arithmetic mean roughness (Ra). For example, the surface roughness of the outer peripheral surface 81 is made smaller than that of the surface of the support 8 other than the outer peripheral surface 81 by a treatment such as polishing. With this configuration, the support 8 rotates more smoothly.

Further, in this basic configuration, the hardness of the outer peripheral surface 81 of the support body 8 is lower than the peripheral surfaces of the plurality of outer pins 23 and higher than the inner peripheral surface 221 of the gear body 22 . "Hardness" as used in the present disclosure means the degree of hardness of an object, and the hardness of a metal is represented, for example, by the size of depressions formed by pressing a steel ball with a certain pressure. Specifically, examples of metal hardness include Rockwell hardness (HRC), Brinell hardness (HB), Vickers hardness (HV), Shore hardness (Hs), and the like. Methods for increasing (hardening) the hardness of metal parts include, for example, alloying or heat treatment. In this basic configuration, as an example, the hardness of the outer peripheral surface 81 of the support 8 is increased by carburizing and quenching. With this configuration, the rotation of the support 8 is less likely to generate abrasion powder and the like, and the smooth rotation of the support 8 can be easily maintained for a long period of time.

(4) Application Examples Next, application examples of the gear device 1 and the actuator 100 according to the basic configuration will be described.

The gear device 1 and the actuator 100 according to the present basic configuration are applied to robots such as, for example, horizontal articulated robots, so-called SCARA (Selective Compliance Assembly Robot Arm) type robots.

Further, application examples of the gear device 1 and the actuator 100 according to the present basic configuration are not limited to the above-described horizontal articulated robots, and are, for example, industrial robots other than horizontal articulated robots, or non-industrial robots. There may be. Examples of industrial robots other than horizontal articulated robots include vertical articulated robots and parallel link robots. Examples of non-industrial robots include household robots, nursing care robots, medical robots, and the like.

(Embodiment 1)
<Overview>
As shown in FIGS. 11 to 17 and the like, the internal meshing planetary gear device 1A (hereinafter also simply referred to as the "gear device 1A") according to the present embodiment mainly has a structure around the inner pin 4 and an input shaft (eccentric The structure around the shaft 7) is different from the gear device 1 according to the basic configuration. Hereinafter, the same reference numerals are given to the same configurations as the basic configuration, and the description thereof will be omitted as appropriate.

FIG. 11 is a schematic cross-sectional view of the gear device 1A. FIG. 12 is a schematic cross-sectional view of the gear device 1A with a bush 70, which will be described later, removed. FIG. 13 is a side view of the gear device 1A viewed from the input side of the rotation axis Ax1 (left side in FIG. 11). 11 corresponds to a cross-sectional view along line A1-A1 of FIG. 13, and FIG. 12 corresponds to a cross-sectional view along line B1-A1 of FIG. FIG. 14 is a side view of the gear device 1A viewed from the output side of the rotation axis Ax1 (right side in FIG. 11). In FIGS. 13 and 14, enlarged views of respective Z1-Z1 line cross sections are shown in balloons. FIG. 15 is a schematic cross-sectional view similar to FIG. 12 (corresponding to a cross-sectional view taken along the line B1-A1 in FIG. 13) with cover bodies 163 and 164 and oil seals 14 and 15, which will be described later, removed. FIG. 16 is a side view of the gear device 1A with the covers 163, 164 and the oil seals 14, 15 removed, viewed from the input side of the rotation axis Ax1 (left side in FIG. 15). FIG. 17 is a side view of the gear device 1A with the covers 163 and 164 and the oil seals 14 and 15 removed, viewed from the output side (right side in FIG. 15) of the rotation shaft Ax1.

The gear device 1A according to the present embodiment has a first main difference from the basic configuration, in which at least the bearing member 6A, the internal gear 2, and the planetary gear 3 are combined, and the plurality of inner pins 4 are detachable. That is, the gear device 1A includes an 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 in a state in which the bearing member 6A, the internal gear 2, and the planetary gear 3 are combined, Each of the plurality of inner pins 4 is detachable. Here, the plurality of inner pins 4 are inserted into the plurality of loose fitting holes 32 formed in the planetary gear 3, and revolve in the loose fitting holes 32 to rotate around the rotation axis Ax1 with respect to the internal gear 2. rotates relative to the center. Further, the plurality of inner pins 4 are arranged inside the inner ring 61 (of the bearing member 6A) when viewed in a direction parallel to the rotation axis Ax1.

The second main difference from the basic configuration of the gear device 1A according to the present embodiment is that the structure (support structure 40) that supports the plurality of inner pins 4 is a rolling bearing that supports both end portions of the inner pins 4. It is a structure to hold at 41 and 42 . That is, the gear device 1A includes a plurality of sets of rolling bearings 41 and 42 that hold the plurality of inner pins 4 on both sides of the planetary gear 3 in the direction parallel to the rotation axis Ax1. Each of the plurality of inner pins 4 is held by each pair of rolling bearings 41 and 42 in a rotatable state. Similarly to the inner pin 4, the rolling elements 402 (see FIG. 20) of the rolling bearings 41 and 42 are also detachable in a state in which at least the bearing member 6A, the internal gear 2 and the planetary gear 3 are combined. It is configured. Specifically, the rolling elements 402 (see FIG. 20) of the rolling bearings 41 and 42 are removed on the side opposite to the planetary gear 3 with respect to the outer ring 62 (of the bearing member 6A) in the direction parallel to the rotation axis Ax1. It is possible.

A third major difference from the basic configuration of the gear device 1A according to the present embodiment is that the bush 70 is provided with a fixing structure 701 for fixing a mating member to the eccentric shaft 7 as the input shaft. It is That is, the gear device 1</b>A includes an input shaft (eccentric shaft 7 ) that eccentrically oscillates the planetary gears 3 and a bush 70 . The bush 70 has a fixing structure 701 for fixing a mating member, is coupled to the input shaft (eccentric shaft 7), and rotates together with the input shaft (eccentric shaft 7).

In short, the main differences between the gear device 1A according to the present embodiment and the basic configuration are the structure around the inner pin 4, particularly the detachment of the inner pin 4, and the support structure 40 (rolling mechanism) for the inner pin 4. Ingenuity about the bearings 41, 42) is newly adopted. Further, the main difference from the basic configuration of the gear device 1A is that the structure around the input shaft (eccentric shaft 7), especially the bush 70, is newly devised. Here, the rolling bearings 41 and 42 are fixed to the inner ring 61 of the bearing member 6A, and the inner pin 4 is held by the inner ring 61 of the bearing member 6A via the rolling bearings 41 and 42. Therefore, in the gear device 1A according to the present embodiment as well, the point that each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state is the same as in the basic configuration.

<Other differences>
In the gear device 1A according to the present embodiment, in addition to the above-described main differences (the structure around the inner pin 4 and the structure around the input shaft), as will be described below, there are a plurality of There are differences.

As another first difference, in the gear device 1A according to this embodiment, the bearing member 6A includes a first bearing member 601A and a second bearing member 602A. The first bearing member 601A and the second bearing member 602A each consist of an angular contact ball bearing and have an inner ring 61, an outer ring 62 and a plurality of rolling elements 63. As shown in FIG. 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 outer peripheral surface that is a perfect circle centered on the rotation axis Ax1 in plan view. Specifically, as shown in FIG. 11, a first bearing member 601A is arranged on the input side (left side in FIG. 11) of the rotation axis Ax1 as seen from the planetary gear 3, and the rotation axis Ax1 as seen from the planetary gear 3. A second bearing member 602A is disposed on the output side of (right side in FIG. 11). The bearing member 6A receives a load in the radial direction, a load in the thrust direction (direction along the rotation axis Ax1), and a bending force (bending moment load) with respect to the rotation axis Ax1 at the first bearing member 601A and the second bearing member 602A. It is constructed to withstand both.

Here, the first bearing member 601A and the second bearing member 602A are arranged on both sides of the planetary gear 3 in the direction parallel to the rotation axis Ax1 and in opposite directions to each other 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 a "back-to-back combination type" in which the respective inner rings 61 receive a load in the thrust direction (direction along the rotation axis Ax1) toward each other. Further, in the gear device 1A, the first bearing member 601A and the second bearing member 602A are combined in a state in which an appropriate preload is applied to the inner ring 61 by tightening the respective inner rings 61 toward each other. The term "preload" as used in the present disclosure means to create a state in which internal stress is always acting by applying pressure in advance, and is a so-called preload. That is, in the gear device 1A according to the present embodiment, in each of the first bearing member 601A and the second bearing member 602A, the rolling elements 63 are pressed against the outer ring 62 from the outside in the direction parallel to the rotation axis Ax1. .

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

The output flange 19 has a plurality (six as an example) of carrier pins 191 (see FIG. 12) projecting from one surface of the output flange 19 toward the input side of the rotation axis Ax1. These plurality of carrier pins 191 pass through a plurality (six as an example) of carrier holes 34 formed in the planetary gear 3, and their tips are attached to the carrier flange 18 by carrier bolts 181 (see FIG. 12). fixed. Here, the diameter of the carrier pin 191 is slightly smaller than the diameter of the carrier hole 34, and a gap is secured between the carrier pin 191 and the inner peripheral surface of the carrier hole 34. It is movable within, i.e., movable relative to the center of the carrier hole 34 . Moreover, the gap between the carrier pin 191 and the inner peripheral surface of the carrier hole 34 is larger than the gap between the inner pin 4 and the inner peripheral surface 321 of the loose fitting hole 32 , and the inner pin 4 revolves in the loose fitting hole 32 . The carrier pin 191 does not come into contact with the inner peripheral surface of the carrier hole 34 when the carrier pin 191 is pressed. A plurality of flange bolt holes 192 (see FIG. 17) for fixing the output flange 19 itself are formed on the surface of the output flange 19 opposite to the carrier pin 191 .

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

As a result, the gear device 1A is used so that the rotation corresponding to the rotation component of the planetary gear 3 is taken out 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 configuration, the relative rotation between the planetary gear 3 and the internal gear 2 is taken out as the rotation component of the planetary gear 3 from the inner ring 61 connected to the planetary gear 3 by the plurality of inner pins 4. be In contrast, in this embodiment the relative rotation between the planetary gear 3 and the internal gear 2 is taken from the carrier flange 18 and the output flange 19 integral with the inner ring 61 . In this embodiment, as an example, the gear device 1A is used in a state where the outer ring 62 of the bearing member 6A is fixed to a case that is a fixed member. That is, the planetary gear 3 is connected to a carrier flange 18 and an output flange 19, which are rotating members, by a plurality of inner pins 4, and the gear body 22 is fixed to a fixed member. Relative rotation between is taken from the rotating members (carrier flange 18 and output flange 19). In other words, in this embodiment, when the plurality of inner pins 4 rotate relative to the gear body 22, the rotational forces of the carrier flange 18 and the output flange 19 are taken out as output.

As another third difference, in this embodiment, the case 10 is seamlessly integrated with the gear body 22 of the internal gear 2 . That is, in the basic configuration, the gear body 22 of the internal gear 2 is used while being fixed to the case 10 together with the outer ring 62 of the bearing member 6 . In contrast, in the present embodiment, the gear main body 22, which is a fixed member, and the case 10 are provided seamlessly and continuously in the direction parallel to the rotation axis Ax1.

More specifically, the case 10 is cylindrical and constitutes the outer shell of the gear device 1A. In this embodiment, the central axis of the cylindrical case 10 is configured to coincide with the rotation axis Ax1. That is, at least the outer peripheral surface of the case 10 forms a perfect circle centered on the rotation axis Ax1 in a plan view (viewed from one side in the direction of the rotation axis Ax1). The case 10 is formed in a cylindrical shape with open end faces in the direction of the rotation axis Ax1. Here, the gear body 22 of the internal gear 2 is seamlessly integrated with the case 10, and the case 10 and the gear body 22 are treated as one component. Therefore, the inner peripheral surface of the case 10 includes the inner peripheral surface 221 of the gear body 22 . Further, an outer ring 62 of the bearing member 6A is fixed to the case 10. As shown in FIG. That is, the outer ring 62 of the first bearing member 601A is fitted and fixed to the input side (left side in FIG. 11) of the rotating shaft Ax1 when viewed from the gear body 22 on the inner peripheral surface of the case 10 . On the other hand, the outer ring 62 of the second bearing member 602A is fitted and fixed to the output side (right side in FIG. 11) of the rotating shaft Ax1 as viewed from the gear body 22 on the inner peripheral surface of the case 10 .

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

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

These two planetary gears 3 (first planetary gear 301 and second planetary gear 302) are arranged with a phase difference of 180 degrees around the rotation axis Ax1. In the example of FIG. 11, the center C1 of the first planetary gear 301 located on the input side of the rotation axis Ax1 (left side in FIG. 11) of the first planetary gear 301 and the second planetary gear 302 is positioned relative to the rotation axis Ax1. It is shifted (biased) upward in the figure. On the other hand, the center C2 of the second planetary gear 302 located on the output side (right side in FIG. 11) of the rotation axis Ax1 is deviated (biased) downward in the figure with respect to the rotation axis Ax1. By arranging the plurality of planetary gears 3 evenly in the circumferential direction about the rotation axis Ax1 in this way, it is possible to balance the weight among the plurality of planetary gears 3 . In the gear device 1A according to this embodiment, the weight balance is achieved among the plurality of planetary gears 3 in this way, so the gap 75 (see FIG. 3) of the eccentric shaft 7 is omitted.

More specifically, the eccentric shaft 7 has two eccentric portions 72 with respect to one shaft center portion 71 . The centers (central axes) of these two eccentric portions 72 coincide with centers C1 and C2, respectively, which are shifted from the rotation axis Ax1. Moreover, the shape itself of the 1st planetary gear 301 and the 2nd planetary gear 302 is common. The opening 33 of the first planetary gear 301 accommodates the eccentric body bearing 5 attached to the eccentric portion 72 centering on the center C1. The opening 33 of the second planetary gear 302 accommodates the eccentric bearing 5 attached to the eccentric portion 72 centering on the center C2. Here, the distance ΔL1 between the rotation axis Ax1 and the center C1 is the eccentricity of the first planetary gear 301 with respect to the rotation axis Ax1, and the distance ΔL2 between the rotation axis Ax1 and the center C2 is the eccentricity with respect to the rotation axis Ax1. 2 becomes the amount of eccentricity of the planetary gear 302 .

18 and 19 show the states of the first planetary gear 301 and the second planetary gear 302 at a certain time. 18 is a cross-sectional view taken along the line A1-A1 of FIG. 11 and shows the first planetary gear 301. FIG. 19 is a cross-sectional view taken along the line B1-B1 of FIG. 11 and shows the second planetary gear 302. FIG. However, in FIGS. 18 and 19, illustration of the retainer 54 is omitted, and hatching is omitted even in the cross section. As shown in FIGS. 18 and 19, the centers C1 and C2 of the first planetary gear 301 and the second planetary gear 302 are located 180 degrees rotationally symmetrical with respect to the rotation axis Ax1. In this embodiment, the eccentricity ΔL1 and the eccentricity ΔL2 are opposite in direction when viewed from the rotation axis Ax1, but have the same absolute value. According to the above-described configuration, the first planetary gear 301 and the second planetary gear 302 rotate around the rotation axis Ax1 with a phase difference of 180 degrees around the rotation axis Ax1. , rotates (eccentrically) about the rotation axis Ax1.

As a fifth difference, in this embodiment, as shown in FIG. 11, the eccentric body bearing 5 is a roller bearing instead of the deep groove ball bearing described in the basic configuration. That is, in the gear device 1</b>A according to this embodiment, the eccentric body bearing 5 uses columnar (cylindrical) rollers as the rolling elements 53 . Furthermore, in this embodiment, the eccentric inner ring 51 (see FIG. 3) and the eccentric outer ring 52 (see FIG. 3) are omitted. Therefore, the inner peripheral surface of (the opening 33 of) the planetary gear 3 serves as 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 replaces the eccentric inner ring 51 with the plurality of rolling elements. It becomes the rolling surface of the rolling element 53 . In this embodiment, the eccentric body bearing 5 has a retainer 54, and the plurality of rolling elements 53 are held by the retainer 54 in a rotatable state. The retainer 54 retains the plurality of rolling elements 53 at equal pitches 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 and is relatively rotatable with respect to each of the planetary gear 3 and the eccentric shaft 7 . As a result, the plurality of rolling elements 53 held by the cage 54 move in the circumferential direction of the eccentric portion 72 as the cage 54 rotates.

As another sixth point of difference, the gear device 1A according to this embodiment includes a support ring 8A instead of the support body 8, as shown in FIG. The support ring 8A is arranged between two planetary gears 3, a first planetary gear 301 and a second planetary gear 302. As shown in FIG. The support ring 8A has an annular shape in which at least the outer peripheral surface is a perfect circle in plan view. The position of the support ring 8A is restricted by bringing the outer peripheral surface thereof into contact with the plurality of outer pins 23 of the internal gear 2. As shown in FIG. Since the plurality of outer pins 23 form the inner teeth 21 of the internal gear 2, in other words, the position of the support ring 8A is restricted by bringing the outer peripheral surface thereof into contact with the inner teeth 21. As shown in FIG. Here, the diameter of the outer peripheral surface of the support ring 8A is the same as the diameter of a virtual circle (tip circle) passing through the tips of the internal teeth 21 of the internal gear 2 . Therefore, all of the plurality of outer pins 23 contact the outer peripheral surface of the support ring 8A. Therefore, when the support ring 8A is positionally restricted by the plurality of outer pins 23, the center of the support ring 8A is positionally restricted so as to overlap the center of the internal gear 2 (rotational axis Ax1).

Here, the support ring 8A is sandwiched between the first planetary gear 301 and the second planetary gear 302, and rotates around the rotation axis Ax1 as the planetary gear 3 rotates (rotates on its axis). At this time, since the support ring 8A rotates with its outer peripheral surface in contact with the plurality of outer pins 23, each of the plurality of outer pins 23 rotates (rotates) as the support ring 8A rotates. Therefore, the support ring 8A constitutes a needle bearing (needle roller bearing) together with the internal gear 2, and rotates smoothly. That is, if the gear body 22 of the internal gear 2 is regarded as an "outer ring" and the support ring 8A as an "inner ring", the plurality of outer pins 23 interposed therebetween function as "rollers". Thus, the support ring 8A constitutes a needle bearing together with the internal gear 2 (the gear body 22 and the plurality of outer pins 23), enabling smooth rotation. Furthermore, since the support ring 8A sandwiches the plurality of outer pins 23 between itself and the gear body 22, the support ring 8A suppresses movement of the outer pins 23 away from the inner peripheral surface 221 of the gear body 22. It also functions as a "stopper".

As another seventh difference, the gear device 1A according to this embodiment includes a spacer 55 as shown in FIG. The spacer 55 is arranged between the first bearing 91 and the second bearing 92 which are inner bearing members and the eccentric bearing 5 . Specifically, the spacer 55 is provided between the first bearing 91 and the eccentric bearing 5 on the first planetary gear 301 side, and between the second bearing 92 and the eccentric bearing 5 on the second planetary gear 302 side. , respectively, are placed. The spacer 55 has an annular shape in which at least the inner peripheral surface is a perfect circle in plan view. The spacer 55 functions as a "presser" for the eccentric bearing 5, and restricts movement of the eccentric bearing 5 (especially the retainer 54) in a direction parallel to the rotation axis Ax1.

Here, the spacer 55 secures a gap between the outer rings of the first bearing 91 and the second bearing 92 . Therefore, in the first bearing 91 and the second bearing 92 , only the inner ring contacts the spacer 55 without the outer ring contacting the spacer 55 . On the other hand, the first bearing member 601A and the second bearing member 602A, which are the bearing member 6A, secure a gap between them and the planetary gear 3 . Therefore, the first bearing member 601A and the second bearing member 602A do not come into contact with the planetary gear 3.

Another eighth point of difference is that the gear device 1A according to the present embodiment is configured so that preload is applied to each inner pin 4 from the planetary gear 3 when the plurality of inner pins 4 are not rotating with respect to the internal gear 2. is configured to That is, in the gear device 1A, when the plurality of inner pins 4 are not rotating with respect to the internal gear 2, the inner peripheral surfaces 321 of the plurality of loose fitting holes 32 are pressed against each of the plurality of inner pins 4. preload is applied. Here, the gear device 1A supports each of the plurality of inner pins 4 with a support structure 40 (rolling bearings 41, 42) so as to maintain a state in which preload is applied. The support structure 40 supports each of the plurality of inner pins 4 so as to cancel the moment generated in each of the plurality of inner pins 4 by preload.

According to this configuration, in the gear device 1A according to the present embodiment, the inner pin 4 is always in contact with the planetary gear 3 at a portion of the inner peripheral surface 321 of the loosely fitting hole 32. A state in which the planetary gear 3 is separated is less likely to occur. Therefore, when the gear device 1</b>A is driven, the inner pin 4 revolves inside the loose fitting hole 32 while being pressed against the inner peripheral surface 321 of the loose fitting hole 32 . In general, a gap is secured between the inner peripheral surface of the loose fitting hole and the inner pin when the gear device is not driven with the gear device assembled in consideration of assembly tolerance and the like. The gear device 1A according to the embodiment is intentionally configured to eliminate the gap. Therefore, according to the gear device 1A according to the present embodiment, it is possible to reduce or eliminate at least the backlash (backlash) due to the gap between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4, thereby reducing the angular transmission error. is easy to keep small. In particular, in the gear device 1A with a high reduction ratio, even if there is backlash due to a small gap, the error in the rotation of the output side (output flange 19) relative to the rotation of the input side (eccentric shaft 7), that is, the angular transmission error is large. Therefore, the effect of reducing or eliminating the backlash is great.

In addition to the above points, for example, the number of teeth of the internal gear 2 and the planetary gear 3, the reduction ratio, the number of the loose fitting holes 32 and the inner pins 4, and the specific shape and dimensions of each part, etc. This embodiment differs from the basic configuration as appropriate. For example, while 18 loose fitting holes 32 and 18 inner pins 4 are provided in the basic configuration, 6 each are provided as an example in this embodiment.

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

First, as a premise, in the gear device 1A according to the present embodiment, the inner pin 4 moves (revolves) in the loose fitting hole 32 as the planetary gear 3 moves eccentrically. The amount of movement of the inner pin 4 at this time is twice the amount of eccentricity ΔL1 (=ΔL2) in the linear direction orthogonal to the rotation axis Ax1 (for example, the vertical direction in FIG. 11). That is, the diameter Di of the loose fitting hole 32 is ideally represented by "Di=di+2ΔL1" using the diameter di of the inner pin 4. As shown in FIG. Therefore, the inner pin 4 is inserted into the loose fitting hole 32 while securing a spatial margin (clearance) between itself and the inner peripheral surface 321 of the loose fitting hole 32 . However, both the diameter di of the inner pin 4 and the diameter Di of the loose fitting hole 32 are difficult to conform to the designed values (ideal values), and they slightly vary within the range of tolerance. 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 loose fitting hole 32 and the inner pin 4 becomes large, and this gap causes a backlash. Transmission error increases. Conversely, if the diameter di of the inner pin 4 is larger than the design value, the gap between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4 becomes small, and the torque required to rotate the eccentric shaft 7 ( input torque) increases, and the loss in the gear device 1A increases.

Here, in the present embodiment, as described above, each of the plurality of inner pins 4, in a state in which at least the bearing member 6A, the internal gear 2, and the planetary gear 3 are combined, passes through the inner pin path Sp1, Removable. That is, in the gear device 1A, each of the plurality of inner pins 4 can be removed without dismantling (disassembling) at least the bearing member 6A, the internal gear 2, and the planetary gear 3. Here, since the inner pin passage Sp1 is positioned on at least one side of the plurality of inner pins 4 in the direction parallel to the rotation axis Ax1, the inner pins 4 move along the direction parallel to the rotation axis Ax1. It is removed through the inner pin passage Sp1.

In other words, 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. It is possible to remove each of the inner pins 4 of the . By removing the inner pin 4, the inner pin 4 can be replaced. That is, after removing the inner pin 4, by reassembling another inner pin 4 or the same inner pin 4 after maintenance (grinding or cleaning), at least the bearing member 6A, the internal gear 2 and the planetary gear 3 The inner pin 4 can be replaced, etc., in a state in which . The inner pin 4 to be reassembled is also inserted through the inner pin passage Sp1 in the same manner as when removed.

In short, according to the above configuration, in the gear device 1A according to the present embodiment, the inner pin 4 can be replaced without dismantling at least the bearing member 6A, the internal gear 2 and the planetary gear 3. Therefore, for example, if the diameter di of the inner pin 4 is smaller than the design value, by replacing it with an inner pin 4 with a larger diameter, at least the gap between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4 Backlash can be reduced or eliminated, and angle transmission errors can be easily suppressed. Conversely, if the diameter di of the inner pin 4 is larger than the design value, the input torque required to rotate the eccentric shaft 7 can be reduced by replacing the inner pin 4 with one having a smaller diameter. It is easy to keep the loss in the gear device 1A small. In particular, in the gear device 1A with a high reduction ratio, even if there is backlash due to a small gap, the error in the rotation of the output side (output flange 19) relative to the rotation of the input side (eccentric shaft 7), that is, the angular transmission error is large. Therefore, the effect of reducing or eliminating the backlash is great.

Furthermore, according to the configuration of the present embodiment, the angle transmission error can be reduced when the gear device 1A starts rotating from a stopped state. Responsiveness at the time of starting 1A or switching the direction of rotation is greatly improved. As a result, for example, the gear device 1A can exhibit sufficient characteristics even in a field such as a robot field in which stopping, starting, or switching of the rotation direction is frequently performed and in which there is a strict requirement for angular transmission error. .

Moreover, in this embodiment, each of the plurality of inner pins 4 is held by the inner ring 61 in a rotatable state. Strictly speaking, however, each inner pin 4 is not held directly by the inner ring 61, but by the carrier flange 18 and the output flange 19 integrated with the inner ring 61 (via rolling bearings 41 and 42). By being held, it is held indirectly by the inner ring 61 of the bearing member 6A. In this way, according to the configuration in which the inner pin 4 is held rotatably, the gap between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4 is small, and the inner pin 4 is positioned inside the loose fitting hole 32 . Even if the inner pin 4 revolves around the loose fitting hole 32 while being pressed against the peripheral surface 321 , the inner pin 4 rolls on the inner peripheral surface 321 of the loose fitting hole 32 . In other words, the inner pin 4 revolves within the loosely fitting hole 32 while rolling on the inner peripheral surface 321 of the loosely fitting hole 32 , so that the inner pin 4 and the inner peripheral surface 321 of the loosely fitting hole 32 . Loss due to frictional resistance 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 in a direction parallel to the rotation axis Ax1. That is, the plurality of inner pins 4 are arranged inside the bearing member 6A (the first bearing member 601A and the second bearing member 602A). Since the plurality of inner pins 4 are arranged inside the bearing member 6A in this manner, the inner pins 4 can be removed simply by securing the inner pin passage Sp1 inside the bearing member 6A. Specifically, the carrier flange 18 and the output flange 19 inside the bearing member 6A are formed with holes into which the plurality of inner pins 4 are inserted. By opening one side, the inner pin passage Sp1 can be realized. According to this configuration, it is possible to suppress an increase in the dimension of the gear device 1A in the radial direction (direction orthogonal to the rotation axis Ax1).

Further, in the gear device 1A according to the present embodiment, as shown in FIG. 15, the inner pin paths Sp1 are positioned on both sides of the plurality of inner pins 4 in the direction parallel to the rotation axis Ax1. That is, both the input side of the rotation axis Ax1 (left side in FIG. 15) and the output side of the rotation axis Ax1 (right side in FIG. 15) as viewed from the plurality of inner pins 4 can be opened by the inner pin path Sp1. be. Therefore, each of the plurality of inner pins 4 can be removed from either the input side or the output side of the rotating shaft Ax1. Furthermore, it is also possible to remove the existing inner pin 4 from the other direction parallel to the rotation axis Ax1 by pushing the existing inner pin 4 from one direction parallel to the rotation axis Ax1. Therefore, when replacing the inner pin 4, for example, the existing inner pin 4 is pushed by the new inner pin 4 from the input side of the rotation axis Ax1, and the existing inner pin 4 is pushed from the output side of the rotation axis Ax1. 4 can be removed and at the same time a new inner pin 4 can be inserted.

Further, in the present embodiment, the inner pin path Sp1 is not always open, but is covered with the covers 163 and 164 at least when the gear device 1A is in use. Cover bodies 163 and 164 are removably attached to carrier flange 18 and output flange 19, for example. Specifically, the cover body 163 is detachably attached to the carrier flange 18 and covers the inner pin path Sp1 on the input side of the rotation axis Ax1 when attached to the carrier flange 18 . The cover body 164 is detachably attached to the output flange 19 and covers the inner pin path Sp1 on the output side of the rotating shaft Ax1 when attached to the output flange 19 .

In short, the gear device 1A according to this embodiment further includes cover bodies 163 and 164 . The cover bodies 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 cover bodies 163 and 164 are attached to the carrier flange 18 and the output flange 19 (states shown in FIGS. 11 and 12) corresponds to the “first position”, and from the carrier flange 18 and the output flange 19 The removed state (the state of FIG. 15) corresponds to the "second position". Cover bodies 163 and 164 need only be movable between the first and second positions, and need not be removable from carrier flange 18 and output flange 19 .

Moreover, 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, so six inner pin paths Sp1 are provided on each of the input side and the output side of the rotation axis Ax1. The cover body 163 is configured not to individually cover the six inner pin paths Sp1 on the input side of the rotation axis Ax1, but to collectively cover them. Similarly, the cover body 164 is configured to collectively cover the six inner pin paths Sp1 on the output side of the rotating shaft Ax1 instead of individually covering them one by one. Therefore, when the cover body 163 is removed, as shown in FIG. 16, the six inner pin paths Sp1 on the input side of the rotation axis Ax1 are exposed, and when the cover body 164 is removed, as shown in FIG. The six inner pin paths Sp1 on the output side of the rotation axis Ax1 are exposed.

Specifically, each of the cover bodies 163 and 164 has an annular shape in which the outer peripheral surface and the inner peripheral surface are perfectly circular in plan view. The positions of the covers 163 and 164 are restricted by bringing the outer peripheral surfaces thereof into contact with the carrier flange 18 and the output flange 19 . That is, each of the carrier flange 18 and the output flange 19 has a recess that opens outward in a direction parallel to the rotation axis Ax1. The cover bodies 163, 164 are attached to the carrier flange 18 and the output flange 19 so as to fit into these recesses. Further, oil seals 14 and 15 are fitted inside the cover bodies 163 and 164, respectively. That is, the cover bodies 163 and 164 are combined with the oil seals 14 and 15 so that the inner peripheral surfaces of the covers 163 and 164 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 in a direction parallel to the rotation axis Ax1 are restricted by the cover bodies 163 and 164. As shown in FIG.

As an example in this embodiment, the cover bodies 163 and 164 are attached to the carrier flange 18 and the output flange 19 with a plurality of (six as an example) mounting screws 160 as shown in FIGS. That is, the cover body 163 is fixed to the carrier flange 18 by tightening the six mounting screws 160 into the screw holes 183 (see FIG. 16) of the carrier flange 18 while being fitted in the recesses of the carrier flange 18. be. The cover body 164 is fixed to the output flange 19 by tightening the six mounting screws 160 into the screw holes 193 (see FIG. 17) of the output flange 19 while being fitted in the depressions of the output flange 19 . The material of the cover bodies 163 and 164 is metal such as stainless steel, cast iron, carbon steel for machine structural use, chrome molybdenum steel, phosphor bronze, or aluminum bronze, like the other parts.

An opening hole 165 is formed in the cover body 163 as shown in FIG. The opening holes 165 are provided at positions corresponding to the carrier bolts 181 when the cover body 163 is attached to the carrier flange 18 . In this embodiment, since there are six carrier bolts 181, six opening holes 165 are also provided. The opening hole 165 functions as a relief hole for the head of the carrier bolt 181 to escape. Further, an opening hole 166 is formed in the cover body 164 as shown in FIG. The opening holes 166 are provided at respective positions corresponding to the flange bolt holes 192 when the cover body 164 is attached to the output flange 19 . In this embodiment, since there are six flange bolt holes 192, six opening holes 166 are also provided. The opening holes 166 function as through holes that expose the flange bolt holes 192 .

Moreover, in this embodiment, a positioning structure is further provided for positioning the cover bodies 163 and 164 and the inner ring 61 relative to each other. As an example, the positioning structure consists of a protrusion 167 (see FIG. 15) and recesses 184, 194 (see FIGS. 16 and 17). Specifically, convex portions 167 are provided on surfaces of the cover bodies 163 and 164 facing the carrier flange 18 and the output flange 19 respectively. Concave portions 184 and 194 are provided at positions corresponding to the convex portion 167 on the surfaces of the carrier flange 18 and the output flange 19 facing the cover bodies 163 and 164 (that is, the bottom surfaces of the concave portions). The cover body 163 is combined with the carrier flange 18 so that the projection 167 is fitted into the recess 184 of the carrier flange 18, so that the inner ring 61 of the first bearing member 601A is integrated with the carrier flange 18. Relatively positioned. Similarly, the cover body 164 is combined with the output flange 19 so that the projection 167 is fitted into the recess 194 of the output flange 19, so that the inner ring 61 of the second bearing member 602A integrated with the output flange 19 is mounted. are positioned relative to each other.

With such a positioning structure, it is possible to determine the relative positions of the cover bodies 163 and 164 with respect to the inner ring 61 with high accuracy. That is, when viewed from a direction parallel to the rotation axis Ax1, the positions of the cover bodies 163 and 164 can be defined with high accuracy. Particularly in this embodiment, the positions of the oil seals 14 and 15 when viewed from the direction parallel to the rotation axis Ax1 are regulated by the cover bodies 163 and 164, so the positional accuracy of the cover bodies 163 and 164 is improved. As a result, poor centering of the oil seals 14 and 15 is suppressed. As a result, leakage of the lubricant from the lubricant holding space 17 sealed by the oil seals 14 and 15 can be easily suppressed.

Moreover, it is preferable that the positioning structure uniquely determines the relative position between the cover members 163 and 164 and the inner ring 61 in the direction of rotation about the rotation axis Ax1. As a result, the covers 163 and 164 are combined with the inner ring 61 of the bearing member 6A in non-rotational symmetry, that is, 360 degrees rotational symmetry when the rotation axis Ax1 is the axis of symmetry. In the present embodiment, as an example, as shown in FIG. 16, a plurality of concave portions 184 of the carrier flange 18 (in this case, 2) are provided. Similarly, as shown in FIG. 17, a plurality (here, two) of recesses 194 of the output flange 19 are provided at positions that are rotationally asymmetric about the rotation axis Ax1 as viewed from the output side of the rotation axis Ax1. It is As a result, relative positional accuracy of the cover bodies 163 and 164 with respect to the inner ring 61 is further improved.

Further, in the present embodiment, each of the plurality of inner pins 4 is at least partially held by the inner ring 61 (of the bearing member 6A) at the same position as the bearing member 6A in the direction parallel to the rotation axis Ax1. That is, as shown in FIG. 15, the plurality of sets of rolling bearings 41 and 42 serving as the support structure 40 for holding (supporting) the inner pin 4 are arranged in the direction parallel to the rotation axis Ax1 such that the first bearing member 601A and the second bearing member 601A It is located at a position that at least partially overlaps with the bearing member 602A. That is, in the direction parallel to the rotation axis Ax1, at least part of the rolling bearing 41 is at the same position as the first bearing member 601A, and at least 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 each of the first bearing member 601A and the second bearing member 602A is approximately the dimension in the width direction of each of the rolling bearings 41 and 42. are identical. Therefore, in the direction parallel to the rotation axis Ax1, each of the first bearing member 601A and the second bearing member 602A is substantially accommodated within the range of each of the rolling bearings 41 and 42. As shown in FIG. In other words, each of the first bearing member 601A and the second bearing member 602A is arranged outside each of the rolling bearings 41 and 42 .

Thus, in this embodiment, the space inside the bearing member 6A (the first bearing member 601A and the second bearing member 602A) originally provided in the gear device 1A is replaced by the support structure 40 that supports the inner pin 4. Use as installation space. Therefore, an increase in the dimension of the gear device 1A in the direction parallel to the rotation axis Ax1 due to the provision of the support structure 40 can be suppressed.

In particular, in this embodiment, the support structure 40 (rolling bearings 41, 42) is outside the inner bearing members (first bearing 91 and second bearing 92) and the bearing member 6A (first bearing member 601A and second bearing member 601A). It is located inside the bearing member 602A). In other words, the rolling bearings 41 and 42 utilize 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). are placed. Therefore, it is possible to suppress an increase in the dimension of the gear device 1A in the radial direction (the direction perpendicular to the rotation axis Ax1) due to the provision of the rolling bearings 41 and 42.

In addition, the inner pin path Sp1 communicates with the lubricant holding space 17 that holds the lubricant. Specifically, the inner pin path Sp1 is connected to the lubricant holding space 17 through holes for inserting the inner pin 4 in the carrier flange 18 and the output flange 19 . According to this configuration, it is possible to replenish the lubricant holding space 17 from the inner pin path Sp<b>1 when replacing the inner pin 4 or the like.

By the way, in this embodiment, the pair of rolling bearings 41 and 42 hold both ends of the inner pin 4 in the longitudinal direction so that the inner pin 4 can rotate. Here, each rolling bearing 41, 42 has a cage (retainer) 401 and a plurality of rolling elements 402, as shown in FIG. The carrier flange 18 and the output flange 19 also serve as the outer ring 403 of each rolling bearing 41 , 42 . Specifically, the inner peripheral surfaces of the holes for inserting the inner pin 4 in the carrier flange 18 and the output flange 19 function as the outer rings 403 of the respective rolling bearings 41 and 42 . The outer ring 403 has a perfect circular shape in a plan view, and the inner diameter of the outer ring 403 is one size larger than the diameter (outer diameter) of the inner pin 4 . occurs. A plurality of rolling elements 402 are arranged in the gap between the outer ring 403 and the inner pin 4 . A plurality of rolling elements 402 are arranged side by side in the circumferential direction of the outer ring 403 . The plurality of rolling elements 402 are all metal parts having the same shape, and are provided at equal pitches over the entire circumference of the outer ring 403 . The cage 401 holds a plurality of rolling elements 402 at equal pitches in the circumferential direction of the outer ring 403 .

As an example in this embodiment, each of the rolling bearings 41 and 42 is a needle bearing (needle roller bearing). That is, each rolling bearing 41 , 42 has a cylindrical roller as the rolling element 402 . The axes of the cylindrical rolling elements 402 are all arranged parallel to the rotation axis Ax1. In this embodiment, each rolling bearing 41, 42 does not have an inner ring, and the inner pin 4 functions as an inner ring. Therefore, according to the rolling bearings 41 and 42, the rolling elements 402 roll to rotate the inner pin 4 with respect to the outer ring 403, and the rolling bearings 41 and 42 enable the inner pin 4 to rotate. can hold.

According to this configuration, the inner pin 4 can rotate, and loss due to frictional resistance between the inner peripheral surface 321 of the loose fitting hole 32 and the inner pin 4 is unlikely to occur in the first place, so the inner roller can be omitted. be. Therefore, in the present embodiment, the inner pin 4 without the inner roller is inserted into the loose fitting hole 32 so that the inner pin 4 directly contacts the inner peripheral surface 321 of the loose fitting hole 32 . . As a result, the inner roller can be omitted and the diameter of the loose fitting hole 32 can be kept relatively small, so that the size of the planetary gear 3 can be reduced (especially, the diameter can be reduced), and the size of the gear device 1A as a whole can be reduced. Easier to plot. Moreover, 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 carrier flange 18 and the output flange 19 is less likely to occur.

On the other hand, the arrangement of the multiple pairs 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 multiple 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 the direction parallel to the rotation axis Ax1, the plurality of sets of rolling bearings 41, 42 is placed on this virtual circle VC1. Particularly in this embodiment, as shown in FIG. 20, the plurality of sets of rolling bearings 41 and 42 are arranged at equal intervals in the circumferential direction around the rotation axis Ax1 when viewed from the direction parallel to the rotation axis Ax1. Although FIG. 20 shows the arrangement of the rolling bearing 41, the arrangement of the rolling bearing 42 is the same. In addition, in FIG. 20, hatching is appropriately omitted even in the cross section.

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, when viewed from a direction parallel to the rotation axis Ax1, the virtual circle VC1 passes through the center of each of the plurality of rolling bearings 41 (or 42) and is a virtual circle between two adjacent rolling bearings 41 (or 42). The distance on VC1 is uniform across multiple rolling bearings 41 (or 42). According to this arrangement, while the plurality of inner pins 4 are held by the plurality of sets of rolling bearings 41 and 42, the force applied to the plurality of inner pins 4 can be evenly distributed during driving of the gear device 1A.

Furthermore, in this embodiment, as shown in FIG. 20, the center of the virtual circle VC1 passing through the centers of the multiple pairs of rolling bearings 41 and 42 coincides with the rotation axis Ax1 when viewed from the direction parallel to the rotation axis Ax1. In other words, the center of the virtual circle VC1 is on the rotation axis Ax1, like the center of the gear body 22 of the internal gear 2, the center of the pitch circle of the internal gear 21, or the like. According to this configuration, the center of the gear body 22 of the internal gear 2 and the rotation centers of the plurality of inner pins 4 relative to the internal gear 2 are easily maintained on the rotation axis Ax1 with high accuracy. As a result, the gear device 1A is advantageous in that problems such as vibration caused by poor centering and reduction in transmission efficiency are less likely to occur.

<Structure around the input shaft>
Next, the structure around the input shaft (eccentric shaft 7) in the gear device 1A according to this embodiment will be described in detail.

In this embodiment, as described above, the gear device 1A includes the bushing 70 that is coupled to the input shaft (eccentric shaft 7) that eccentrically oscillates the planetary gears 3 and that rotates together with the input shaft (eccentric shaft 7). Bushing 70 has a fixing structure 701 for fixing a mating member.

According to the above configuration, in the gear device 1A according to the present embodiment, the mating member is not directly fixed to the input shaft such as the eccentric shaft 7, but the mating member is fixed via the bush 70 coupled to the input shaft. The member will be fixed. Therefore, the outer diameter of the input shaft (the shaft center portion 71 of the eccentric shaft 7) can be made smaller than when the mating member is directly fixed to the end surface of the input shaft. As a result, it is possible to provide the gear device 1A that can be easily miniaturized. In particular, in the gear device 1A with a high reduction ratio, since the rotation input from the mating member to the input shaft is high speed, the coupling between the input shaft and the mating member is required to be relatively strong. According to the configuration of this embodiment, the mating member is fixed to the fixing structure 701 of the bushing 70, so that it can be coupled with the input shaft relatively firmly without increasing the outer diameter of the input shaft.

Specifically, the bush 70 has a cylindrical shape in which at least the inner peripheral surface is a perfect circle in a plan view. The center (central axis) of the bush 70 coincides with the rotation axis Ax1. An end portion of the bush 70 on the output side of the rotating shaft Ax1 constitutes an insertion port 702 (see FIG. 12) having an enlarged inner diameter. 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 . As a result, the bush 70 can be coupled to the eccentric shaft 7 by fitting the input-side end of the rotating shaft Ax<b>1 in the axial center portion 71 of the eccentric shaft 7 into the insertion opening 702 . That is, in this embodiment, the bush 70 has an insertion opening 702 and is coupled to the input shaft (eccentric shaft 7 ) with a portion of the input shaft (eccentric shaft 7 ) inserted into the insertion opening 702 . The material of the bushing 70 is metal such as stainless steel, cast iron, carbon steel for machine structural use, chrome molybdenum steel, phosphor bronze, or aluminum bronze, like other parts.

Further, in a state where a part of the eccentric shaft 7 is inserted (fitted) into the insertion port 702, the bush 70 and the eccentric shaft 7 are coupled by press fitting. Further, bushing 70 is coupled to the input shaft at least by gluing. Specifically, the bush 70 is firmly coupled to the eccentric shaft 7 with an adhesive applied to the inner peripheral surface of the insertion port 702 . In short, in this embodiment, the bushing 70 is coupled to the input shaft (eccentric shaft 7) by both press fitting and adhesion. Thereby, a strong connection between the bushing 70 and the eccentric shaft 7 is realized.

Furthermore, the outer diameter of the bushing 70 is at least larger than the outer diameter of the axial center portion 71 of the eccentric shaft 7 . Therefore, when the bush 70 is coupled to the eccentric shaft 7 , the bush 70 protrudes like a flange at the input side end of the rotation axis Ax<b>1 of the eccentric shaft 7 . Here, the bush 70 is positioned on the input side of the rotation axis Ax1 as viewed from the first bearing 91, which is the inner bearing member. As a result, the first bearing 91, which is the inner bearing member, is positioned between the eccentric portion 72 and the bush 70 in the direction parallel to the rotation axis Ax1. Therefore, the bush 70 functions as a "presser" for the first bearing 91, and restricts movement of the inner bearing member (first bearing 91) in the direction parallel to the rotation axis Ax1. In short, the gear device 1A according to the present embodiment includes an inner bearing member (first bearing 91) that rotatably holds the input shaft (eccentric shaft 7) with respect to the inner ring 61 (indirectly). The bush 70 restricts movement of the inner bearing member (first bearing 91) to one side in the direction parallel to the rotation axis Ax1.

Furthermore, in this embodiment, the input shaft (eccentric shaft 7) and the bushing 70 have a through hole 73 passing through along the rotation axis Ax1. In other words, the through hole 73 penetrates from the axial center portion 71 of the eccentric shaft 7 to the bush 70 along the rotation axis Ax1. Here, since the fixing structure 701 for fixing the mating member is provided on the bush 70, if the outer diameter of the eccentric shaft 7 is the same, the diameter of the through hole 73 is made larger than when the bush 70 is not provided. easy to secure. That is, since it is not necessary to provide a fixing structure to the eccentric shaft 7 itself, it is easy to reduce the thickness of the eccentric shaft 7 (the shaft center portion 71 thereof), and as a result, it is easy to enlarge the through hole 73 .

As an example in this embodiment, the fixing structure 701 consists of a screw hole. That is, it is possible to fix the mating member to the bush 70 by screwing the mating 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 (here, six) of screw holes are provided as the fixing structure 701 (see FIG. 13) so that the mating member can be fixed with a plurality of screws. When the mating member is fixed using such a fixing structure 701, the mating member is fixed to the bush 70 on the input side of the rotation axis Ax1. That is, the fixing structure 701 is configured to be capable of fixing a mating member to one side of the bush 70 in the direction parallel to the rotation axis Ax1.

Further, in the present embodiment, the fixing structure 701 is at least partially at the same position as the input shaft in the direction parallel to the rotation axis Ax1. That is, as shown in FIG. 15, the fixing structure 701 for fixing the mating member is located at a position that at least partially overlaps the input shaft (eccentric shaft 7) in the direction parallel to the rotation axis Ax1. As a result, it is possible to suppress an increase in the dimension of the gear device 1A in the direction parallel to the rotation axis Ax1 while the fixing structure 701 is relatively large.

Furthermore, in the present embodiment, the inner pin path Sp1 is provided, and the inner pin path Sp1 allows the inner pin 4 to be removed even when the bush 70 is still coupled to the eccentric shaft 7 . That is, the gear device 1A is positioned on at least one side in a direction parallel to the rotation axis Ax1 with respect to the plurality of inner pins 4, and in a state in which the input shaft (eccentric shaft 7) and the bush 70 are combined, the plurality of An inner pin path Sp1 is provided to allow each of the inner pins 4 to be removed. Therefore, in the gear device 1A, it is possible to remove each of the plurality of inner pins 4 even after the bush 70 is coupled to the input shaft (eccentric shaft 7).

<How to replace the inner pin, etc.>
Next, a method of replacing the inner pin 4 and the rolling elements 402 of the rolling bearings 41 and 42 in the gear device 1A according to this embodiment will be described with reference to FIGS. 21 and 22. FIG. Here, as an example, in the manufacturing process of the gear device 1A, for the purpose of adjusting the performance (backlash, input torque, etc.) of the gear device 1A, a worker replaces the inner pin 4 and the rolling bearings 41, 42, etc. will be explained.

When replacing the inner pin 4 and the rolling elements 402, the operator removes the mounting screws 160 and removes the cover bodies 163, 164 and the oil seals 14, 15 from the carrier flange 18 and the output flange 19 (see FIG. 15). ). By removing the covers 163 and 164, the inner pin path Sp1 is exposed.

When replacing the inner pin 4, the operator pushes the new inner pin 4A into the carrier flange 18 from the inner pin path Sp1 on the input side of the rotary shaft Ax1, for example, as shown in FIG. At this time, the existing inner pin 4 pushed by the new inner pin 4A is pushed out to the output side of the rotating shaft Ax1. The existing inner pin 4 is removed when the new inner pin 4A is completely inserted. In this method, since at least one of the new inner pin 4A and the existing inner pin 4 is always inserted into each of the rolling bearings 41 and 42, the plurality of rolling elements 402 of the rolling bearings 41 and 42 are kept inside. The pin 4, 4A prevents the pin from falling off.

Furthermore, in the above method, the inner pins 4 can be replaced one by one, so each time the inner pin 4 is replaced, the gear device 1A is driven on a trial basis to improve the performance (backlash, input torque, etc.). can be confirmed. As a result, for example, there is an advantage that it is easy to identify the defective inner pin 4, and it is easy to adjust the performance of the gear device 1A to the desired performance.

When replacing the rolling elements 402, the operator, for example, removes the existing rolling elements 402 from the inner pin path Sp1 on the output side of the rotating shaft Ax1, as shown in FIG. At this time, as a means for extracting the rolling elements 402, for example, a jig such as a magnet is appropriately used. Then, the operator inserts a new rolling element 402 from the inner pin path Sp1 on the output side of the rotating shaft Ax1.

Furthermore, in the above method, since the rolling elements 402 can be replaced one by one, each time the rolling element 402 is replaced, the gear device 1A is driven on a trial basis to improve the performance (backlash, input torque, etc.). can be confirmed. Accordingly, there is an advantage that, for example, it is easy to identify the defective rolling element 402, and it is easy to adjust the performance of the gear device 1A to the desired performance.

When replacing both the inner pin 4 and the rolling elements 402, the operator attaches the cover bodies 163, 164 and the oil seals 14, 15 to the carrier flange 18 and the output flange 19 after completing the replacement. By attaching the covers 163 and 164, the inner pin path Sp1 is blocked.

However, the method illustrated in FIG. 21 is only an example, and the operator may push the new inner pin 4A into the output flange 19 from the inner pin path Sp1 on the output side of the rotating shaft Ax1, for example. Furthermore, when replacing the inner pin 4, the operator may remove the inner pin 4 once and then replace it with a new inner pin 4A, similarly to the rolling element 402. Also, 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 and the rolling bearings 41 and 42 is not limited to the manufacturing process of the gear device 1A, and may be performed, for example, during maintenance work or the like during the period of use of the gear device 1A. That is, the maintenance method for the gear device 1A according to the present embodiment is a state in which the bearing member 6A, the internal gear 2, and the planetary gear 3 are combined, and the plurality of inner pins 4 are rotated in a direction parallel to the rotation axis Ax1. replacing at least one of the plurality of inner pins 4 from at least one side of the . Further, in the method for manufacturing the gear device 1A according to the present embodiment, in a state in which the bearing member 6A, the internal gear 2, and the planetary gear 3 are combined, from at least one side in a direction parallel to the rotation axis Ax1, a plurality of A step of inserting the inner pin 4 is provided.

<Application example>
The gear device 1A according to this embodiment constitutes a robot joint device 200 together with a first member 201 and a second member 202, as shown in FIG. In other words, the robot joint device 200 according to this embodiment includes the gear device 1A, the first member 201, and the second member 202. As shown in FIG. The first member 201 is fixed to the outer ring 62 . The second member 202 is fixed to the inner ring 61 . FIG. 23 is a schematic cross-sectional view of the robot joint device 200. As shown in FIG.

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

The robot joint device 200 configured in this manner functions as a joint device by relatively rotating the first member 201 and the second member 202 about the rotation axis Ax1. Here, by driving the eccentric shaft 7 of the gear device 1A with the first motor 203 as the drive source 101 (see FIG. 1), the first member 201 and the second member 202 rotate relatively. At this time, the rotation (input rotation) generated by the drive source 101 is reduced at a relatively high speed reduction ratio in the gear device 1A to drive the first member 201 or the second member 202 with relatively high torque. That is, the first member 201 and the second member 202 that are connected by the gear device 1A can bend and stretch about the rotation axis Ax1.

More specifically, a first pulley P1 is fixed to the output shaft of the first motor 203 . A second pulley P2 is connected to the first pulley P1 via a timing belt T1. Here, the second pulley P2 is fixed to the fixing structure 701 of the bush 70 as a mating member. That is, when the first motor 203 is driven, its rotation is transmitted to the eccentric shaft 7 as an input shaft via the first pulley P1, the timing belt T1 and the second pulley P2.

The robot joint device 200 further includes a second motor 204 . A third pulley P3 is fixed to the output shaft of the second motor 204 . A fourth pulley P4 is connected to the third pulley P3 via a timing belt T2. Here, the fourth pulley P4 is fixed to the shaft 205. As shown in FIG. The shaft 205 passes through the bushing 70 and the eccentric shaft 7 through the through hole 73 . A fifth pulley P5 is fixed to the end of the shaft 205 opposite to the fourth pulley P4. Accordingly, when the second motor 204 is driven, its rotation is transmitted to the fifth pulley P5 via the third pulley P3, the timing belt T2, the fourth pulley P4 and the shaft 205.

The robot joint device 200 is used, for example, in a robot such as a horizontal articulated robot (SCARA robot). Furthermore, the robot joint device 200 is not limited to horizontal articulated robots, and may be used, for example, in industrial robots other than horizontal articulated robots or non-industrial robots. Further, the gear device 1A according to the present embodiment is not limited to the robot joint device 200, and may be used in a vehicle such as an automated guided vehicle (AGV) as a wheel device such as an in-wheel motor. good.

<Modification>
Embodiment 1 is but one of various embodiments of the present disclosure. Embodiment 1 can be modified in various ways according to design and the like, as long as the object of the present disclosure can be achieved. In addition, the drawings referred to in this disclosure are all schematic diagrams, and the ratio of the size and thickness of each component in the drawings does not necessarily reflect the actual dimensional ratio. . Modifications of the first embodiment are listed below. Modifications described below can be applied in combination as appropriate.

In Embodiment 1, the gear device 1A with two types of planetary gears 3 was exemplified, 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, these three planetary gears 3 are preferably arranged with a phase difference of 120 degrees around the rotation axis Ax1. Further, the gear device 1A may include only one planetary gear 3. Alternatively, when the gear device 1A includes three planetary gears 3, two planetary gears 3 out of the three planetary gears 3 are in the same phase, and the remaining one planetary gear 3 is 180 degrees around the rotation axis Ax1. They may be arranged with a phase difference.

Moreover, it is not essential that both ends of the inner pin 4 are held by the rolling bearings 41 and 42 , and only one end may be held by the rolling bearings 41 and 42 .

In addition, the inner pin paths Sp1 need only be located on at least one side of the plurality of inner pins 4 in the direction parallel to the rotation axis Ax1, and need not be located on both sides. Moreover, the cover bodies 163 and 164 are not essential and can be omitted as appropriate. Furthermore, it is not essential that 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. 164 may be provided. Further, it is not essential that the inner pin path Sp<b>1 communicates with the lubricant holding space 17 , and the inner pin path Sp<b>1 may be separated from the lubricant holding space 17 .

Moreover, it is not essential that the bush 70 has the insertion opening 702, and the insertion opening 702 can be omitted as appropriate. Furthermore, it is not essential that the bush 70 is bonded to the input shaft (eccentric shaft 7) by adhesion, and it may be bonded only by press-fitting, for example. Moreover, it is not an essential configuration that the bush 70 restricts the movement of the inner bearing member (the first bearing 91) to one 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 also not essential. In addition, it is not essential that the fixed structure 701 is at least partially in the same position as the input shaft in the direction parallel to the rotation axis Ax1.

Further, the plurality of sets of rolling bearings 41 and 42 may not be arranged at regular intervals in the circumferential direction around the rotation axis Ax1 when viewed from the 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 multiple sets of rolling bearings 41 and 42 does not have to coincide with the rotation axis Ax1.

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

Further, the bearing member 6A may be a cross roller bearing, or a deep groove ball bearing or the like, as in the basic configuration. However, the bearing member 6A is, for example, a four-point contact ball bearing or the like, in which the load in the radial direction, the load in the thrust direction (direction along the rotation axis Ax1), and the bending force (bending moment load) with respect to the rotation axis Ax1 are applied. It is preferable to be able to withstand both.

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

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

Further, the gear device 1A only needs to be able to take out the relative rotation between the inner ring 61 and the outer ring 62 of the bearing member 6 as output, and the rotational force of the inner ring 61 (carrier flange 18 and output flange 19) as output. It is not limited to the configuration to be taken out. For example, the rotational force of the outer ring 62 (case 10) that rotates relative to the inner ring 61 may be extracted as an output.

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

Further, the gear device 1A may have inner rollers. That is, in the gear device 1A, it is not essential for each of the plurality of inner pins 4 to be in direct contact with the inner peripheral surface 321 of the loose fitting hole 32. An inner roller may be interposed between. In this case, the inner roller is mounted on the inner pin 4 and is rotatable around the inner pin 4 .

Further, each of the plurality of inner pins 4 may be held by the inner ring 61 in a rotatable state. not required in 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 carrier flange 18, the output flange 19, or the like integrated with the inner ring 61.

Further, the support ring 8A is not essential in the gear device 1A, and the support ring 8A may be omitted as appropriate, or the support body 8 described in the basic configuration may be used instead of the support ring 8A.

In addition, the gear device 1A employs at least one of the detachment of the inner pin 4, the support structure 40 (rolling bearings 41, 42) for the inner pin 4, and the bush 70. It is not essential to adopt all of these. That is, the gear device 1</b>A may adopt only one of, for example, the detachment of the inner pin 4 and the detachment of the bush 70 .

Further, since the gear device 1A may adopt at least one of the preloading of the inner pin 4 and the support structure 40 of the inner pin 4, other configurations may be appropriately omitted or changed from the basic configuration. It is possible. For example, in the gear device 1A, similarly to the first related art, the inner pin 4 is held in a state of being pressed into the inner ring 61 (or the carrier flange 18 or the output flange 19 integrated with the inner ring 61). may In this case, each of the plurality of inner pins 4 is held in a state in which it cannot rotate with respect to the inner ring 61 . Moreover, each of the plurality of inner pins 4 does not have to be arranged at the same position as the bearing member 6A in the axial direction of the bearing member 6A.

Moreover, the input shaft to which the bush 70 is coupled may be configured to eccentrically oscillate the planetary gear 3 during rotation, and is not limited to a configuration in which the shaft center portion 71 and the eccentric portion 72 are integrated like the eccentric shaft 7. . For example, the input shaft to which the bushing 70 is coupled may be the shaft center portion 71 configured separately from the eccentric portion 72. In this case, the input shaft (shaft center portion 71) to which the bushing 70 is coupled , the eccentric portion 72 is attached.

Further, the positioning structure for relatively positioning the cover bodies 163, 164 and the inner ring 61 is limited to a structure that uniquely determines the relative positions of the cover bodies 163, 164 and the inner ring 61 in the direction of rotation about the rotation axis Ax1. do not have. The positioning structure may, for example, be capable of positioning the cover bodies 163 and 164 rotationally symmetrically with respect to the inner ring 61 of the bearing member 6A when the rotational axis Ax1 is the axis of symmetry. Furthermore, the positioning structure is not limited to the convex portion 167 and the concave portions 184 and 194, and may be realized by fitting tolerances of the cover bodies 163 and 164 with respect to the carrier flange 18 and the output flange 19, for example. Furthermore, the positioning structure is not an essential component and can be omitted as appropriate.

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

Also, the spaces between the cover bodies 163 and 164 and the carrier flange 18 and the output flange 19 may be sealed by, for example, O-rings. Thereby, it is possible to improve the sealing performance of the lubricant holding space 17 .

(summary)
As described above, the internally meshing planetary gear device (1, 1A) according to the first aspect includes bearing members (6, 6A), internal gears (2), planetary gears (3), and a plurality of inner pin (4) and 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), the inner ring (61) having a rotation axis (Ax1) with respect to the outer ring (62). It is rotatably supported relative to the center. The internal gear (2) has internal teeth (21) and is fixed to the outer ring (62). The planetary gear (3) has external teeth (31) that partially mesh with the internal teeth (21). A plurality of inner pins (4) are arranged inside the inner ring (61) when viewed in a direction parallel to the rotation axis (Ax1), and are respectively fitted in a plurality of loose fitting holes (32) formed in the planetary gear (3). In the inserted state, it rotates relatively to the internal gear (2) while revolving in the loose fitting hole (32). The inner pin path (Sp1) is positioned on at least one side of the plurality of inner pins (4) in a direction parallel to the rotation axis (Ax1), and includes the bearing members (6, 6A) and the internal gear (2). and the planetary gear (3) are combined, each of the plurality of inner pins (4) can be removed.

According to this aspect, the inner pin (4) can be replaced without dismantling at least the bearing members (6, 6A), the internal gear (2) and the planetary gear (3). Therefore, for example, if the diameter of the inner pin (4) is smaller than the design value, by replacing it with an inner pin (4) with a larger diameter, at least the inner peripheral surface (321) of the loose fitting hole (32) and the inner pin (4) It is possible to reduce or eliminate the backlash caused by the gap between and (4), and it is easy to keep the angle transmission error small. As a result, it is possible to provide an internal meshing planetary gear system (1, 1A) that can easily suppress angular transmission errors.

In the internally meshing planetary gear device (1, 1A) according to the second aspect, in the first aspect, the inner pin path (Sp1) is arranged along the rotation axis (Ax1) with respect to the plurality of inner pins (4). Located on both sides in parallel directions.

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 rotating shaft (Ax1).

The internal meshing planetary gear device (1, 1A) according to the third aspect is, in the first or second aspect, a first position covering the inner pin path (Sp1) and exposing the inner pin path (Sp1). It further comprises a cover body (163, 164) that is movable between a second position that allows the

According to this aspect, normally, by covering the inner pin path (Sp1) with the cover body (163, 164), it is easy to prevent the inner pin (4) from coming off through the inner pin path (Sp1). .

In the internal meshing planetary gear device (1, 1A) according to the fourth aspect, in the third aspect, the cover body (163, 164) includes a plurality of inner pins (4) corresponding to the plurality of inner pins (4) at the first position. The inner pin paths (Sp1) are collectively covered.

According to this aspect, the moving operation of the cover body (163, 164) is simple.

The internally meshing planetary gear device (1, 1A) according to the fifth aspect further includes a positioning structure for relatively positioning the cover body (163, 164) and the inner ring (61) in the third or fourth aspect. Prepare.

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

In the internal meshing planetary gear device (1, 1A) according to the sixth aspect, in the fifth aspect, the positioning structure includes the cover bodies (163, 164) and the inner ring in the direction of rotation about the rotation axis (Ax1). A unique position relative to (61) is determined.

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

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

According to this aspect, the inner pin (4) revolves in the loose fitting hole (32) while rolling on the inner peripheral surface (321) of the loose fitting hole (32). Loss due to frictional resistance between the inner peripheral surface (321) of and the inner pin (4) is less likely to occur.

An internally meshing planetary gear device (1, 1A) according to an eighth aspect is, in the seventh aspect, provided with a plurality of inner pins on both sides of the planetary gear (3) in a direction parallel to the rotation axis (Ax1). It further comprises a plurality of sets of rolling bearings (41, 42) holding each of (4).

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

In the internal meshing planetary gear system (1, 1A) according to the ninth aspect, in the eighth aspect, the rolling elements (402) of the rolling bearings (41, 42) are arranged in a direction parallel to the rotation axis (Ax1). , the outer ring (62) on the opposite side of the planetary gear (3).

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

In the internally meshing planetary gear device (1, 1A) according to the tenth aspect, in any one of the first to ninth aspects, each of the plurality of inner pins (4) extends in a direction parallel to the rotation axis (Ax1). , at least a portion of which 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 internally meshing planetary gear device (1, 1A) according to the eleventh aspect, in any one of the first to tenth aspects, the inner pin path (Sp1) includes a lubricant holding space (17 ).

According to this aspect, it is possible to replenish the lubricant through the inner pin path (Sp1).

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

According to this aspect, it is possible to provide the robot joint device (200) that can easily suppress the angle transmission error.

A maintenance method according to a thirteenth aspect is an internally meshing planetary gear including bearing members (6, 6A), an internal gear (2), a planetary gear (3), and a plurality of inner pins (4). It is used in the device (1, 1A). The bearing member (6, 6A) has an outer ring (62) and an inner ring (61) arranged inside the outer ring (62), the inner ring (61) having a rotation axis (Ax1) with respect to the outer ring (62). It is rotatably supported relative to the center. The internal gear (2) has internal teeth (21) and is fixed to the outer ring (62). The planetary gear (3) has external teeth (31) that partially mesh with the internal teeth (21). A plurality of inner pins (4) are arranged inside the inner ring (61) when viewed in a direction parallel to the rotation axis (Ax1), and are respectively fitted in a plurality of loose fitting holes (32) formed in the planetary gear (3). In the inserted state, it rotates relatively to the internal gear (2) while revolving in the loose fitting hole (32). The maintenance method is a state in which the bearing members (6, 6A), the internal gear (2) and the planetary gear (3) are combined, and the plurality of inner pins (4) are rotated parallel to the rotation axis (Ax1). A step of exchanging at least one of the plurality of inner pins (4) from at least one side of the direction.

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

A method for manufacturing an internally meshing planetary gear device (1, 1A) according to a fourteenth aspect comprises bearing members (6, 6A), an internal gear (2), a planetary gear (3), and a plurality of inner pins. (4), and a method for manufacturing an internal meshing planetary gear device (1, 1A). The bearing members (6, 6A) have an outer ring (62) and an inner ring (61) arranged inside the outer ring (62), the inner ring (61) having a rotation axis (Ax1) with respect to the outer ring (62). It is rotatably supported relative to the center. The internal gear (2) has internal teeth (21) and is fixed to the outer ring (62). The planetary gear (3) has external teeth (31) that partially mesh with the internal teeth (21). A plurality of inner pins (4) are arranged inside the inner ring (61) when viewed in a direction parallel to the rotation axis (Ax1), and are respectively fitted in a plurality of loose fitting holes (32) formed in the planetary gear (3). In the inserted state, it rotates relatively to the internal gear (2) while revolving in the loose fitting hole (32). A method for manufacturing an internally meshing planetary gear device (1, 1A) includes: a bearing member (6, 6A), an internal gear (2), and a planetary gear (3) are combined with each other, and are mounted on a rotating shaft (Ax1). It has a step of inserting a plurality of inner pins (4) from at least one side in a parallel direction.

According to this aspect, it is possible to provide a method of manufacturing an internal meshing planetary gear device (1, 1A) that can easily suppress angular transmission errors.

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

Reference Signs List 1, 1A internally meshing planetary gear device 2 internal gear 3 planetary gear 4 inner pin 6, 6A bearing member 17 lubricant holding space 21 internal tooth 31 external tooth 32 loose fitting hole 41, 42 rolling bearing 61 inner ring 62 outer ring 163, 164 cover body 167 convex portion (positioning structure)
184, 194 recess (positioning structure)
200 robot joint device 201 first member 202 second member 402 rolling element Ax1 rotating shaft Sp1 inner pin path

Claims (14)

a bearing member having an outer ring and an inner ring disposed inside the outer ring, wherein the inner ring is supported to be rotatable relative to the outer ring about a rotation axis;
an internal gear having internal teeth and fixed to the outer ring;
a planetary gear having external teeth that partially mesh with the internal teeth;
The internal teeth are arranged inside the inner ring when viewed in a direction parallel to the rotation shaft, and are inserted into a plurality of loose fitting holes formed in the planetary gear, respectively, while revolving in the loose fitting holes. a plurality of inner pins that rotate relative to the gear;
Positioned on at least one side of the plurality of inner pins in a direction parallel to the rotation axis, each of the plurality of inner pins in a state in which the bearing member, the internal gear, and the planetary gear are combined a path for the inner pin that allows the
Inscribed planetary gear system. The inner pin paths are positioned on both sides of the plurality of inner pins in a direction parallel to the rotation axis,
The internally meshing planetary gear system according to claim 1. further comprising 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 device according to claim 1 or 2. 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 system according to claim 3. further comprising a positioning structure for positioning the cover body and the inner ring relative to each other;
The internal meshing planetary gear device according to claim 3 or 4. The positioning structure uniquely determines a relative position between the cover body and the inner ring in a direction of rotation about the rotation axis,
The internal meshing planetary gear system according to claim 5. each of the plurality of inner pins is held by the inner ring in a rotatable state;
The internal meshing planetary gear device according to any one of claims 1 to 6. Further comprising a plurality of sets of rolling bearings holding each of the plurality of inner pins on both sides of the planetary gear in a direction parallel to the rotation axis,
The internal meshing planetary gear system according to claim 7. The rolling elements of the rolling bearing are removable on a side opposite to the planetary gear with respect to the outer ring in a direction parallel to the rotation axis.
The internally meshing planetary gear system according to claim 8. At least a portion of each of the plurality of inner pins is held by the inner ring at the same position as the bearing member in a direction parallel to the rotation axis.
The internal meshing planetary gear device according to any one of claims 1 to 9. The inner pin path communicates with a lubricant holding space that holds a lubricant,
The internal meshing planetary gear device according to any one of claims 1 to 10. an internal meshing planetary gear device according to any one of claims 1 to 11;
a first member fixed to the outer ring;
a second member fixed to the inner ring;
Joint device for robots. a bearing member having an outer ring and an inner ring disposed inside the outer ring, wherein the inner ring is supported to be rotatable relative to the outer ring about a rotation axis;
an internal gear having internal teeth and fixed to the outer ring;
a planetary gear having external teeth that partially mesh with the internal teeth;
The internal teeth are arranged inside the inner ring when viewed in a direction parallel to the rotation shaft, and are inserted into a plurality of loose fitting holes formed in the planetary gear, respectively, while revolving in the loose fitting holes. a plurality of inner pins that rotate relative to the gear, and an internally meshing planetary gear device,
In a state in which the bearing member, the internal gear, and the planetary gear are combined, at least one of the plurality of inner pins is moved from at least one side of the plurality of inner pins in a direction parallel to the rotation axis. having a step of exchanging
maintenance method. a bearing member having an outer ring and an inner ring disposed inside the outer ring, wherein the inner ring is supported to be rotatable relative to the outer ring about a rotation axis;
an internal gear having internal teeth and fixed to the outer ring;
a planetary gear having external teeth that partially mesh with the internal teeth;
The internal teeth are arranged inside the inner ring when viewed in a direction parallel to the rotation shaft, and are inserted into a plurality of loose fitting holes formed in the planetary gear, respectively, while revolving in the loose fitting holes. A method of manufacturing an internal meshing planetary gear device comprising a plurality of inner pins that rotate relative to the gear,
inserting 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 internal gear, and the planetary gear are combined;
A method for manufacturing an internally meshing planetary gear system.

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