JP2024003285A - Internal meshing planetary gear device and articulation device for robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal meshing planetary gear device capable of regulating axial movement of a crankshaft even with a relatively simple configuration, and an articulation device for a robot.

SOLUTION: An internal meshing planetary gear device 1B comprises an internal gear 2, a pair of planetary gears 3, a crankshaft 7A, a pair of carriers 18 and 19, and a regulation structure 9. A crankshaft 7A swings the pair of planetary gears 3 by rotating around an axial core. The pair of carriers 18 and 19 are arranged on both sides in an axial direction along the axial core of the pair of planetary gears 3, and rotatably support the crankshaft 7A. The regulation structure 9 regulates movement of the crankshaft 7A relative to the pair of planetary gears 3 in the axial direction. The regulation structure 9 has a flange part 73 located at at least one place in the axial direction of the crankshaft 7A and arranged so as to be sandwiched between the pair of planetary gears 3.

SELECTED DRAWING: Figure 17

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present disclosure generally relates to an internally meshing planetary gear device and a joint device for a robot, and more particularly to an internally meshing planetary gear device in which a planetary gear having external teeth is disposed inside an internally toothed internal gear. The present invention relates to a robot joint device.

As a related technology, an eccentric oscillation type internal meshing planetary gear device called a distribution type is known (see, for example, Patent Document 1). The internally meshing planetary gear device according to related technology includes a plurality of (for example, three) crankshafts arranged at positions offset from the axis of the internal gear, and each crankshaft is driven synchronously by the crankshaft gear. By doing so, the planetary gear (external gear) is internally engaged with the internal gear while being oscillated.

The planetary gears include a first planetary gear and a second planetary gear. A pair of carriers are arranged on both sides of the first planetary gear and the second planetary gear in the axial direction. Each crankshaft is supported by a pair of carriers via a pair of tapered roller bearings. When the input gear rotates, the three crankshaft gears meshing with the input gear at the same time rotate in the same direction and at the same rotational speed. Since the crankshaft is spline-connected to each crankshaft gear, the three crankshafts rotate in the same direction at the same rotational speed while being reduced in speed to the ratio of the number of teeth between the input gear and the crankshaft gear. As a result, the three first eccentric parts formed at the same axial position of the three crankshafts rotate synchronously and swing the first planetary gear, and the three first eccentric parts are formed at the same axial position of the three crankshafts. The three second eccentric parts thus formed rotate synchronously to swing the second planetary gear.

The first planetary gear and the second planetary gear are each internally meshed with the internal gear. The internal gear includes a gear main body and an outer pin (pin member) that is rotatably incorporated into the gear main body and constitutes an internal tooth of the internal gear. Here, the number of teeth of the internal gear (the number of external pins) is slightly greater than the number of teeth of each planetary gear. Therefore, each time each planetary gear oscillates once, the first planetary gear and the second planetary gear are out of phase with respect to the internal gear in the circumferential direction (rotate), and this rotation causes each It is transmitted to a pair of carriers as revolution around the axis (rotation axis) of the internal gear of the crankshaft. Thereby, the pair of carriers can be rotated relative to the gear body (and the casing integrated therewith) around the rotation axis.

Japanese Patent Application Publication No. 2016-75354

In the configuration of the above-mentioned related technology, each crankshaft is supported by a pair of carriers via a pair of tapered roller bearings, and movement in the axial direction is restricted, which makes the configuration complicated and the entire device There is a problem in that it is difficult to miniaturize.

An object of the present disclosure is to provide an internal joint planetary gear device and a robot joint device that are capable of regulating axial movement of a crankshaft, although they have a relatively simple configuration.

An internal meshing planetary gear device according to an aspect of the present disclosure includes an internal gear, a pair of planetary gears, a crankshaft, a pair of carriers, and a regulating structure, and swings the pair of planetary gears. By doing so, the pair of planetary gears are rotated relative to the internal gear. The internal gear has an annular gear main body and a plurality of outer pins that are rotatably held in a plurality of inner circumferential grooves formed on the inner circumferential surface of the gear main body and constitute internal teeth. The pair of planetary gears have external teeth that partially mesh with the internal teeth. The crankshaft swings the pair of planetary gears by rotating around its axis. The pair of carriers are arranged on both sides of the pair of planetary gears in the axial direction along the axis thereof, and rotatably support the crankshaft. The regulating structure regulates movement of the crankshaft relative to the pair of planetary gears in the axial direction. The regulating structure includes a flange portion located at at least one location of the crankshaft in the axial direction and sandwiched between the pair of planetary gears.

A joint device for a robot according to an aspect of the present disclosure includes the internal meshing planetary gear device, a first member fixed to the gear main body, and a robot joint device that controls relative rotation of the pair of planetary gears with respect to the internal gear. Accordingly, a second member that rotates relative to the first member is provided.

According to the present disclosure, it is possible to provide an internal joint planetary gear device and a robot joint device that are capable of regulating the movement of the crankshaft in the axial direction even though they have a relatively simple configuration.

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 seen from the input side of the rotating shaft. FIG. 3 is a schematic exploded perspective view of the internally meshing planetary gear device same as the above, viewed from the output side of the rotating shaft. FIG. 4 is a schematic sectional view of the internally meshing planetary gear device same as the above. FIG. 5 is a sectional view taken along the line A1-A1 in FIG. 4, showing the internally meshing planetary gear device same as the above. FIG. 6 is a sectional view taken along the line B1-B1 in FIG. 4, showing the internally meshing planetary gear device same as the above. FIG. 7 is a schematic cross-sectional view of an internally meshing planetary gear device according to Reference Example 1. FIG. 8 is a schematic diagram of the internal meshing planetary gear device seen from the output side of the rotating shaft. FIG. 9 is a schematic perspective view showing the configuration around the crankshaft of the internally meshing planetary gear device as described above. FIG. 10 is a schematic exploded perspective view showing the configuration around the crankshaft of the internally meshing planetary gear device as described above. FIG. 11 is a schematic perspective view showing the crankshaft of the internally meshing planetary gear device according to the above. FIG. 12 shows the main parts of the internally meshing planetary gear device same as the above, and is a schematic enlarged view of region Z1 in FIG. 7. FIG. 13 shows a main part of the internally meshing planetary gear device same as the above, and is a schematic enlarged view of region Z2 in FIG. 7. FIG. 14 shows a main part of the internally meshing planetary gear device same as the above, and is a schematic enlarged view of region Z1 in FIG. 13. FIG. 15 is a schematic diagram showing a joint device for a robot using the internal meshing planetary gear device as described above. FIG. 16 is a schematic cross-sectional view of the internally meshing planetary gear device according to the first embodiment. FIG. 17 shows a main part of the internally meshing planetary gear device same as the above, and is a schematic enlarged view of region Z1 in FIG. 16. FIG. 18 is a schematic cross-sectional view of a main part of an internally meshing planetary gear device according to a second embodiment. FIG. 19 is a schematic cross-sectional view of essential parts of an internally meshing planetary gear device according to Embodiment 3.

(Basic configuration)
(1) Overview Hereinafter, an overview of the internally meshing planetary gear device 1 according to the present basic configuration will be described with reference to FIGS. 1 to 4. The drawings referred to in this disclosure are all schematic diagrams, and the ratios of the sizes and thicknesses of each component in the drawings do not necessarily reflect the actual dimensional ratios. For example, the tooth profile, dimensions, number of teeth, etc. of the internal teeth 21 and external teeth 31 in FIGS. 1 to 4 are merely shown schematically for explanation, and are limited to the shapes shown in the figures. That's not the purpose.

The 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 and a planetary gear 3. In this gear device 1, a planetary gear 3 is disposed inside an annular internal gear 2, and by swinging the planetary gear 3, the planetary gear 3 is rotated relative to the internal gear 2. Further, the internal meshing planetary gear device 1 further includes a bearing member 6 having an outer ring 62 and an inner ring 61. The inner ring 61 is disposed inside the outer ring 62 and is rotatably supported relative to the outer ring 62. In particular, the gear device 1 according to the present basic configuration is an eccentric oscillation type internal meshing planetary gear device called a distribution type.

As shown in FIGS. 1 to 4, the gear device 1 according to the present basic configuration includes a plurality of cranks (three in the basic configuration) arranged at positions offset from the axis (rotation axis Ax1) of the internal gear 2. It has shafts (eccentric shafts) 7A, 7B, and 7C. Furthermore, the gear device 1 includes an input shaft 500 centered on the rotation axis Ax1, which is disposed on the axis of the internal gear 2 (rotation axis Ax1), and an input gear 501 formed integrally with the input shaft 500. , is equipped with. Crankshaft gears 502A, 502B, and 502C are spline-coupled to the plurality of crankshafts 7A, 7B, and 7C, respectively. These plurality (three in the basic configuration) of crankshaft gears 502A, 502B, and 502C are arranged so as to mesh with the input gear 501. Therefore, when the input shaft 500 is driven, the gear device 1 causes the input gear 501 to synchronously drive the crankshafts 7A, 7B, and 7C, thereby causing the planetary gear 3 to swing.

The internal gear 2 has internal teeth 21 and is fixed to an outer ring 62. In particular, in this basic configuration, the internal gear 2 includes an annular gear main body 22 and a plurality of external pins 23. The plurality of outer pins 23 are held on the inner circumferential 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 in 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 plurality of crankshafts 7A, 7B, and 7C are driven, the planetary gear 3 swings, and the meshing position between the internal teeth 21 and the external teeth 31 moves in the circumferential direction of the internal gear 2. , relative rotation occurs between the planetary gear 3 and the internal gear 2 depending on the difference in the number of teeth 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) as the two gears rotate relative to each other. As a result, a rotational output is obtained from the planetary gear 3, which is reduced at a relatively high reduction ratio in accordance with the difference in the number of teeth between the two gears.

This type of gear device 1 is used so that rotation corresponding to the autorotation component of the planetary gear 3 is extracted as rotation of a pair of carriers 18 and 19 that are integrated with the inner ring 61 of the bearing member 6. Thereby, the gear device 1 functions as a gear device with a relatively high reduction ratio, with the input shaft 500 on the input side and the pair of carriers 18 and 19 on the output side. Therefore, in the gear device 1 according to this basic configuration, in order to transmit the rotation corresponding to the autorotation component of the planetary gear 3 to the pair of carriers 18, 19, the plurality of crankshafts 7A, 7B, 7C are connected to the pair of carriers 18, 19. is supported. The pair of carriers 18 and 19 are arranged on both sides of the planetary gear 3 in the axial direction (direction along the rotation axis Ax1), and rotatably support the respective crankshafts 7A, 7B, and 7C.

Here, the plurality of crankshafts 7A, 7B, 7C are inserted into the plurality of openings 33 formed in the planetary gear 3, and relative to the internal gear 2 as the planetary gear 3 rotates. rotate. Further, each of the crankshafts 7A, 7B, and 7C has an axial center portion 71 and an eccentric portion 72 that is eccentric with respect to the axial center portion 71. The pair of carriers 18, 19 rotatably support the shaft center portion 71 of each crankshaft 7A, 7B, 7C, and the opening 33 of the planetary gear 3 has an eccentric center portion 71 of each crankshaft 7A, 7B, 7C. 72 is inserted. Therefore, the oscillation component of the planetary gear 3, that is, the revolution component of the planetary gear 3, is absorbed by the revolution component of the eccentric portion 72 with respect to the shaft center portion 71. In other words, the eccentric portions 72 of the shaft center portions 71 of the respective crankshafts 7A, 7B, and 7C rotate to revolve around the shaft center portions 71, thereby absorbing the oscillation component of the planetary gear 3. Therefore, the rotation (rotation component) of the planetary gear 3, excluding the oscillation component (revolution component) of the planetary gear 3, is transmitted to the pair of carriers 18, 19 by the plurality of crankshafts 7A, 7B, 7C. It turns out.

Further, the gear device 1 according to the present basic configuration constitutes an actuator 100 together with a drive source 101, as shown in FIG. In other words, the actuator 100 according to the present basic configuration includes the gear device 1 and the drive source 101. The drive source 101 generates a driving force for swinging the planetary gear 3. Specifically, the drive source 101 causes the planetary gear 3 to swing by rotating the input shaft 500 around the rotation axis Ax1.

(2) Definition "Annular" as used in the present disclosure means a ring-like shape that forms a space (region) surrounded by the inner side, at least in plan view, and is similar to a perfect circle in plan view. The shape is not limited to an annular shape, and may be, for example, an elliptical shape or a polygonal shape. Furthermore, even if the shape has a bottom, such as a cup shape, if the peripheral wall thereof is annular, it is included in the "annular shape".

"Revolution" 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 this object, and when an object revolves, the center of this object revolves around the rotation axis. It will move along an orbit centered on . Therefore, for example, if an object rotates around an eccentric axis that is parallel to the central axis passing through the center (center of gravity) of the object, this object will revolve around the eccentric axis as the rotation axis. . As an example, the planetary gear 3 swings and revolves within the internal gear 2 so as to revolve around the rotation axis Ax1.

Further, in the present disclosure, one side of the rotation axis Ax1 (the left side in FIG. 4) may be referred to as the "output side", and the other side (the right side in FIG. 4) of the rotation axis Ax1 may be referred to as the "input side". In the example of FIG. 4, rotation is applied to the input shaft 500 from the "input side" of the rotation axis Ax1, and rotation of the pair of carriers 18 and 19 is taken out from the "output side" of the rotation axis Ax1. However, "input side" and "output side" are merely labels added for the purpose of explanation, and are not intended to limit the positional relationship between the input and output as seen from the gear device 1.

The "rotation axis" in the present disclosure means a virtual axis (straight line) that is the center of the rotational movement of a rotating body. In other words, the rotation axis Ax1 is a virtual axis with no substance. The input shaft 500 rotates around the rotation axis Ax1.

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

(3) Configuration Hereinafter, the detailed configuration of the internally meshing planetary gear device 1 according to the present basic configuration will be explained with reference to FIGS. 1 to 6.

FIG. 1 is a perspective view showing a schematic configuration of an actuator 100 including a gear device 1. As shown in FIG. In FIG. 1, a drive source 101 is schematically shown. FIG. 2 is a schematic exploded perspective view of the gear device 1 viewed from the input side of the rotation axis Ax1. FIG. 3 is a schematic exploded perspective view of the gear device 1 viewed from the output side of the rotating shaft Ax1. FIG. 4 is a schematic cross-sectional view of the gear device 1. FIG. 5 is a sectional view taken along line A1-A1 in FIG. FIG. 6 is a sectional view taken along the line B1-B1 in FIG. However, in FIGS. 5 and 6, hatching is omitted for parts other than the crankshafts 7A, 7B, and 7C even if they are cross sections.

(3.1) Overall configuration As shown in FIGS. 1 to 4, the gear device 1 according to the present basic configuration includes an internal gear 2, a planetary gear 3, a bearing member 6, and a plurality of crankshafts 7A, 7B. , 7C, a pair of carriers 18 and 19, and an input shaft 500. In this basic configuration, the gear device 1 further includes an input gear 501, a plurality of crankshaft gears 502A, 502B, 502C, a pair of rolling bearings 41, 42, an eccentric bearing 5, and a case 10. We are prepared. In this basic configuration, the materials of the internal gear 2, the planetary gear 3, the plurality of crankshafts 7A, 7B, 7C, the pair of carriers 18, 19, etc., which are the components of the gear device 1, are stainless steel, cast iron, mechanical structure grade, etc. Metals such as carbon steel, chromium molybdenum steel, phosphor bronze or aluminum bronze, or light metals such as aluminum or titanium. The metals (including light metals) mentioned here include metals that have been subjected to surface treatment such as nitriding treatment.

Further, in this basic configuration, an internal planetary gear device using trochoidal tooth profiles is illustrated as an example of the gear device 1. That is, the gear device 1 according to the present basic configuration includes an 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 in which the gear main 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 this basic configuration, when the gear device 1 is used in the actuator 100, when a rotational force is applied as an input to the input shaft 500, a pair of carriers 18 and 19 integrated with the inner ring 61 of the bearing member 6 Rotational force is extracted as output. That is, the gear device 1 operates using the rotation of the input shaft 500 as input rotation and the rotation of the pair of carriers 18 and 19 integrated with the inner ring 61 as output rotation. As a result, the gear device 1 can obtain an output rotation that is reduced at a relatively high reduction ratio 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 input shaft 500 in the gear device 1. Specifically, the drive source 101 is connected to the input shaft 500, and the power generated by the drive source 101 is transmitted to the input shaft 500. Thereby, the drive source 101 can rotate the input shaft 500.

Furthermore, in the gear device 1 according to this basic configuration, as shown in FIG. 4, 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 rotation axis Ax1 on the input side is the rotation center of the input shaft 500 to which input rotation is applied, and the rotation axis Ax1 on the output side is the rotation center of the inner ring 61 (and the pair of carriers 18, 19) that generates the output rotation. It is the center of rotation. In other words, in the gear device 1, on the same axis, an output rotation that is reduced at a relatively high reduction ratio with respect to the input rotation is obtained.

The internal gear 2 is an annular component having internal teeth 21, as shown in FIGS. 5 and 6. In this basic configuration, the internal gear 2 has an annular shape in which at least the inner circumferential surface is a perfect circle in plan view. Internal teeth 21 are formed on the inner circumferential surface of the annular internal gear 2 along the circumferential direction of the internal gear 2 . The plurality of teeth constituting the internal teeth 21 all have the same shape, and are provided at equal pitches over the entire circumferential area of the internal peripheral surface of the internal gear 2. That is, the pitch circle of the internal teeth 21 becomes a perfect circle in plan view. The center of the pitch circle of the internal teeth 21 is on the rotation axis Ax1. Further, the internal gear 2 has a predetermined thickness in the direction of the rotation axis Ax1. The tooth traces of the internal teeth 21 are all parallel to the rotation axis Ax1. The dimension of the internal teeth 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 (circular) gear main body 22 and a plurality of external pins 23, as described above. The plurality of outer pins 23 are held on the inner circumferential 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 each function as a plurality of teeth constituting the inner teeth 21. Specifically, as shown in FIG. 2, a plurality of inner circumferential grooves 223 are formed in the inner circumferential surface 221 of the gear body 22 in the entire circumferential direction. The plurality of inner circumferential grooves 223 all have the same shape and are provided at equal pitches. The plurality of inner circumferential grooves 223 are all parallel to the rotation axis Ax<b>1 and are formed over the entire length of the gear body 22 in the thickness direction. The plurality of outer pins 23 are combined with the gear body 22 so as to fit into the plurality of inner circumferential grooves 223. Each of the plurality of outer pins 23 is held in a rotatable state within the inner circumferential groove 223. Further, the gear body 22 is fixed to the case 10 (together with the outer ring 62). Furthermore, a plurality of fixing holes 222 (see FIG. 5) for fixing are formed in the gear body 22.

The planetary gear 3 is an annular component having external teeth 31, as shown in FIGS. 5 and 6. In this basic configuration, the planetary gear 3 has an annular shape in which at least the outer circumferential surface is a perfect circle in plan view. External teeth 31 are formed on the outer peripheral surface of the annular planetary gear 3 along the circumferential direction of the planetary gear 3. The plurality of teeth constituting the external teeth 31 all have the same shape, and are provided at equal pitches over the entire circumferential area of the outer peripheral surface of the planetary gear 3. That is, the pitch circle of the external teeth 31 becomes a perfect circle in plan view. Furthermore, the planetary gear 3 has a predetermined thickness in the direction of the rotation axis Ax1. The external teeth 31 are formed over the entire length of the planetary gear 3 in the thickness direction. The tooth traces of the external teeth 31 are all parallel to the rotation axis Ax1. In the planetary gear 3, unlike the internal gear 2, the external teeth 31 are integrally formed with the main body of the planetary gear 3 from one metal member.

Further, the gear device 1 according to the present basic configuration includes a plurality of planetary gears 3. Specifically, the gear device 1 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. That is, the planetary gear 3 includes a first planetary gear 301 and a second planetary gear 302 that are arranged in a direction (axial direction) parallel to the rotation axis Ax1. The shapes of the first planetary gear 301 and the second planetary gear 302 are the same.

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. 4, of the first planetary gear 301 and the second planetary gear 302, the center of the first planetary gear 301 located on the input side (right side in FIG. 4) of the rotation axis Ax1 (the center of the pitch circle of the external teeth 31) The center) C1 is shifted (biased) upward in the figure with respect to the rotation axis Ax1. On the other hand, the center (center of the pitch circle of the external teeth 31) C2 of the second planetary gear 302 located on the output side (left side in FIG. 4) of the rotation axis Ax1 has shifted downward in the figure with respect to the rotation axis Ax1 ( in a lopsided) state. 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 of the first planetary gear 301 with respect to the rotation axis Ax1. 2 is the eccentricity of the planetary gear 302. In this way, by disposing the plurality of planetary gears 3 evenly in the circumferential direction around the rotation axis Ax1, it is possible to balance the weight and load among the plurality of planetary gears 3. .

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 basic configuration, the eccentricity ΔL1 and the eccentricity ΔL2 have opposite directions when viewed from the rotation axis Ax1, but their absolute values are the same.

More specifically, each of the crankshafts 7A, 7B, and 7C has two eccentric parts 72 with respect to one shaft center part 71, respectively. The eccentricity ΔL0 (see FIGS. 5 and 6) of the center C0 of these two eccentric parts 72 from the center of the shaft center part 71 (shaft center Ax2) is the amount of eccentricity ΔL0 (see FIGS. 5 and 6) of the first planetary gear 301 and the second planetary gear This is the same as the eccentricity ΔL1 and ΔL2 of the gear 302. The shapes of the plurality of crankshafts 7A, 7B, and 7C are common. The plurality of crankshaft gears 502A, 502B, and 502C also have the same shape.

Further, a pair of carriers 18 and 19 are arranged on both sides of the first planetary gear 301 and the second planetary gear 302 in a direction (axial direction) parallel to the rotation axis Ax1. When distinguishing the pair of carriers 18 and 19 from each other, the carrier 18 located on the input side of the rotation axis Ax1 (on the right side in FIG. 4) is referred to as the "input side carrier 18", and In this case, the carrier 19 located on the left side will be referred to as the "output side carrier 19." Each of the crankshafts 7A, 7B, 7C is held at both ends by a pair of carriers 18, 19 via rolling bearings 41, 42. In other words, each crankshaft 7A, 7B, 7C is held by the input side carrier 18 and the output side carrier 19 in a rotatable state on both sides of the planetary gear 3 in a direction (axial direction) parallel to the rotation axis Ax1. ing.

An eccentric bearing 5 is mounted on the eccentric portion 72 of each crankshaft 7A, 7B, 7C. Three openings 33 corresponding to the three crankshafts 7A, 7B, and 7C are formed in each of the first planetary gear 301 and the second planetary gear 302. The eccentric bearing 5 is accommodated in each opening 33. In other words, the eccentric body bearings 5 are attached to the first planetary gear 301 and the second planetary gear 302, and each crankshaft 7A, 7B, 7C is inserted into the eccentric body bearings 5, so that the eccentric body bearings 5 And each crankshaft 7A, 7B, 7C is combined with the planetary gear 3. When the planetary gear 3 is combined with the eccentric bearing 5 and the crankshafts 7A, 7B, 7C, and each crankshaft 7A, 7B, 7C rotates, the planetary gear 3 swings around the rotation axis Ax1.

According to the configuration described above, a rotational force as an input is applied to the input shaft 500, and the input shaft 500 rotates around the rotation axis Ax1, so that this rotational force is transmitted from the input gear 501 to the plurality of crankshafts 7A. , 7B, and 7C. That is, when the input gear 501 rotates, the three crankshaft gears 502A, 502B, and 502C that are meshed with the input gear 501 at the same time rotate in the same direction and at the same rotational speed. Since the crankshafts 7A, 7B, 7C are spline connected to each crankshaft gear 502A, 502B, 502C, the three crankshafts 7A, 7B, 7C are connected to the input gear 501 and the crankshaft gears 502A, 502B, 502C. Rotates in the same direction at the same speed while being decelerated by the tooth ratio. As a result, the three eccentric portions 72 formed at the same position on the input side of the rotation axis Ax1 in the three crankshafts 7A, 7B, and 7C rotate synchronously, causing the first planetary gear 301 to swing. Further, three eccentric portions 72 formed at the same position on the output side of the rotating shaft Ax1 in the three crankshafts 7A, 7B, and 7C rotate synchronously, causing the second planetary gear 302 to swing.

5 and 6 show the states of the first planetary gear 301 and the second planetary gear 302 at a certain point in time. FIG. 5 is a sectional view taken along line A1-A1 in FIG. 4, and shows the first planetary gear 301. As shown in FIG. FIG. 6 is a sectional view taken along the line B1-B1 in FIG. 4, and shows the second planetary gear 302. As shown in FIGS. 5 and 6, the centers C1 and C2 of the first planetary gear 301 and the second planetary gear 302 are located approximately 180 degrees rotationally symmetrically with respect to the rotation axis Ax1. In this basic configuration, the eccentricity ΔL1 and the eccentricity ΔL2 have opposite directions when viewed from the rotation axis Ax1, but their absolute values are substantially the same (both eccentricity ΔL0). According to the above-described configuration, as the shaft center portion 71 rotates (rotates) around the shaft center Ax2, the first planetary gear 301 and the second planetary gear 302 have a phase difference of approximately 180 degrees around the rotation axis Ax1. It rotates (eccentric movement) around the rotation axis Ax1. By arranging the plurality of planetary gears 3 substantially evenly in the circumferential direction around the rotation axis Ax1, it is possible to balance the weight and load among the plurality of planetary gears 3.

The planetary gears 3 (first planetary gear 301 and second planetary gear 302) configured in this way are 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 swing inside the internal gear 2 when 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 disposed 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 a state where the first planetary gear 301 is inscribed in the internal gear 2, the center C1 of the pitch circle of the external teeth 31 in the first planetary gear 301 is from the center of the pitch circle of the internal teeth 21 (rotation axis Ax1). It is located at a position shifted by a distance ΔL1. Similarly, when the second planetary gear 302 is inscribed in the internal gear 2, the center C2 of the pitch circle of the external teeth 31 in the second planetary gear 302 is the center of the pitch circle of the internal teeth 21 (rotation axis Ax1). It is located at a position shifted by a distance ΔL2 from.

Therefore, in both the first planetary gear 301 and the second planetary gear 302, the external teeth 31 and the internal teeth 21 are at least partially opposed to each other with a gap between them. If the difference in the number of teeth is 2 or more, the entire circumferential direction will not mesh with each other. However, since the planetary gear 3 swings (revolutions) 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 gears 3 (the first planetary gear 301 and the second planetary gear 302) swing around the rotation axis Ax1, as shown in FIGS. Some of the teeth will mesh with some of the teeth that constitute the internal teeth 21. As a result, in the gear device 1, it becomes possible to mesh a portion of the external teeth 31 with a portion of the internal teeth 21.

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

Further, in this basic configuration, as an example, the combined thickness of the first planetary gear 301 and the second planetary gear 302 is smaller than the thickness of the gear body 22 in the internal gear 2. Furthermore, the dimension of the external teeth 31 including the first planetary gear 301 and the second planetary gear 302 in the tooth trace direction (parallel to the rotation axis Ax1) is the same as the dimension of the internal teeth 21 in the tooth trace direction (parallel to the rotation axis Ax1). direction). In other words, in the direction parallel to the rotation axis Ax1, the external teeth 31 of the first planetary gear 301 and the second planetary gear 302 fall within the range of the tooth traces of the internal teeth 21.

Here, the first planetary gear 301 and the second planetary gear 302 are each internally meshed with the internal gear 2. Therefore, each time the first planetary gear 301 and the second planetary gear 302 swing once, the first planetary gear 301 and the second planetary gear 302 move with respect to the internal gear 2 (the internal teeth 21 and the external teeth 31 A phase shift occurs in the circumferential direction due to the difference in the number of teeth (with), resulting in rotation. This rotation is transmitted to the pair of carriers 18 and 19 as each crankshaft 7A, 7B, 7C revolves around the axis (rotation axis Ax1) of the internal gear 2. Thereby, the pair of carriers 18 and 19 can be rotated relative to the gear body (and the case 10 integrated therewith) around the rotation axis Ax1.

In short, the gear device 1 according to the present basic configuration uses the swinging of the planetary gear 3 by swinging the planetary gear 3 with a plurality of crankshafts 7A, 7B, and 7C arranged at positions offset from the rotation axis Ax1. to obtain rotational output. That is, in the gear device 1, when the planetary gear 3 swings and the meshing position between the internal teeth 21 and the external teeth 31 moves in the circumferential direction of the internal gear 2, the relationship between the planetary gear 3 and the internal gear 2 changes. Relative rotation according to the difference in the number of teeth occurs between both gears (internal gear 2 and planetary gear 3). Here, if the internal gear 2 is fixed, the planetary gear 3 will rotate (rotate) as the two gears rotate relative to each other. As a result, a rotational output is obtained from the planetary gear 3, which is reduced at a relatively high reduction ratio in accordance with the difference in the number of teeth between the two gears.

The bearing member 6 has an outer ring 62 and an inner ring 61, and is a component for extracting the output of the gear device 1 as rotation of the inner ring 61 relative to the outer ring 62. The bearing member 6 includes, in addition to an outer ring 62 and an inner ring 61, a plurality of rolling elements 63 (see FIG. 4). Both the outer ring 62 and the inner ring 61 are annular parts. Both the outer ring 62 and the inner ring 61 have an annular shape that is a perfect circle in 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 created between the inner circumferential surface of the outer ring 62 and the outer circumferential surface of the inner ring 61.

The plurality of rolling elements 63 are arranged in a gap between the outer ring 62 and the inner ring 61. The plurality of rolling elements 63 are arranged 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 over the entire circumferential area of the outer ring 62 at equal pitches.

More specifically, in the gear device 1 according to this basic configuration, the bearing member 6 includes a first bearing member 601 and a second bearing member 602. The first bearing member 601 and the second bearing member 602 each consist of an angular ball bearing. Specifically, as shown in FIG. 4, the first bearing member 601 is arranged on the input side (right side in FIG. 4) of the rotation axis Ax1 when viewed from the planetary gear 3, and A second bearing member 602 is arranged on the output side (left side in FIG. 4). The bearing member 6 has a first bearing member 601 and a second bearing member 602 that can handle loads in the radial direction, loads in the thrust direction (direction along the rotation axis Ax1), and bending force (bending moment load) with respect to the rotation axis Ax1. It is constructed to withstand both.

Here, the first bearing member 601 and the second bearing member 602 are arranged on both sides of the planetary gear 3 in a direction (axial direction) parallel to the rotation axis Ax1, and in opposite directions to each other in the direction parallel to the rotation axis Ax1. be done. In other words, the bearing member 6 is a "combined angular ball bearing" that is a combination of a plurality of (here, two) angular ball bearings. Here, as an example, the first bearing member 601 and the second bearing member 602 are of a "back-to-back combination type" that receives a load in the thrust direction (direction along the rotation axis Ax1) in which the respective inner rings 61 approach each other. Furthermore, in the gear device 1, the first bearing member 601 and the second bearing member 602 are assembled in a state where an appropriate preload is applied to the inner ring 61 by tightening the respective inner rings 61 in a direction toward each other.

Further, in the gear device 1 according to the present basic configuration, the input side carrier 18 and the output side carrier 19 are arranged on both sides of the planetary gear 3 in a direction parallel to the rotation axis Ax1, and the carrier hole 34 of the planetary gear 3 ( (see FIG. 4). Specifically, as shown in FIG. 4, the input side carrier 18 is disposed on the input side of the rotation axis Ax1 when viewed from the planetary gear 3 (on the right side in FIG. 4), and An output side carrier 19 is arranged on the output side (left side in FIG. 4). The inner ring 61 of the bearing member 6 (of each of the first bearing member 601 and the second bearing member 602) is fixed to the input carrier 18 and the output carrier 19. In this basic configuration, as an example, the inner ring of the first bearing member 601 is seamlessly integrated with the input carrier 18. Similarly, the inner ring of the second bearing member 602 is seamlessly integrated with the output carrier 19.

The output side carrier 19 has a plurality of (three as an example) carrier pins 191 (see FIG. 2) that protrude from one surface of the output side carrier 19 toward the input side of the rotation axis Ax1. These plurality of carrier pins 191 each penetrate a plurality of (three as an example) carrier holes 34 formed in the planetary gear 3, and their tips are connected to the input side carrier 18 by carrier bolts 192 (see FIG. 7). It is fixed at. Here, a gap is ensured between the carrier pin 191 and the inner circumferential surface of the carrier hole 34, and the carrier pin 191 is movable within the carrier hole 34, that is, it is movable relative to the center of the carrier hole 34. It is possible. This prevents the carrier pin 191 from coming into contact with the inner circumferential surface of the carrier hole 34 when the planetary gear 3 swings.

With the above configuration, the gear device 1 is used so that rotation corresponding to the autorotation component of the planetary gear 3 is extracted as rotation of the input side carrier 18 and the output side carrier 19 that are integrated with the inner ring 61 of the bearing member 6. That is, in this basic configuration, the relative rotation between the planetary gear 3 and the internal gear 2 is extracted from the input side carrier 18 and the output side carrier 19. In this basic configuration, as an example, the gear device 1 is used with the outer ring 62 (see FIG. 4) of the bearing member 6 fixed to the case 10, which is a fixed member. That is, the planetary gear 3 is connected to the input side carrier 18 and the output side carrier 19, which are rotating members, by the plurality of crankshafts 7A, 7B, and 7C, and the gear body 22 is fixed to a fixed member, so that the planetary gear 3 and Relative rotation with the internal gear 2 is taken out from the rotating members (input side carrier 18 and output side carrier 19). In other words, in this basic configuration, when the planetary gear 3 rotates relative to the gear body 22, the rotational force of the input side carrier 18 and the output side carrier 19 is extracted as output.

Furthermore, in this basic configuration, the case 10 is seamlessly integrated with the gear body 22 of the internal gear 2. That is, in the direction parallel to the rotation axis Ax1, the gear main body 22, which is a fixed member, and the case 10 are provided seamlessly and continuously.

More specifically, the case 10 has a cylindrical shape and constitutes the outer shell of the gear device 1 . In this basic configuration, the central axis of the cylindrical case 10 is configured to coincide with the rotation axis Ax1. In other words, at least the outer circumferential surface of the case 10 is a perfect circle centered on the rotation axis Ax1 in plan view (viewed from one side in the axial direction). The case 10 is formed into a cylindrical shape with both axial end faces open. Here, the gear body 22 of the internal gear 2 is seamlessly integrated into 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 6 is fixed to the case 10. That is, the outer ring 62 of the first bearing member 601 is fitted and fixed on the input side (right side in FIG. 4) of the rotation axis Ax1 when viewed from the gear body 22 on the inner circumferential surface of the case 10. On the other hand, the outer ring 62 of the second bearing member 602 is fitted and fixed to the output side (left side in FIG. 4) of the rotating shaft Ax1 when viewed from the gear body 22 on the inner peripheral surface of the case 10.

Furthermore, the end face of the input side (the right side in FIG. 4) of the rotation axis Ax1 in the case 10 is closed by the input side carrier 18, and the end face of the output side (the left side in FIG. 4) of the rotation axis Ax1 in the case 10 is closed by the input side carrier 18. It is closed by carrier 19. Therefore, as shown in FIG. 4, in a space surrounded by the case 10, the input side carrier 18, and the output side carrier 19, the planetary gears 3 (first planetary gear 301 and second planetary gear 302), a plurality of outer pins 23, an eccentric bearing 5, and other parts are housed therein.

Each of the plurality of (three in the basic configuration) crankshafts 7A, 7B, and 7C has an axial center portion 71 and two eccentric portions 72. The shaft center portion 71 has a cylindrical shape with at least the outer circumferential surface being a perfect circle in plan view. An axial center Ax2, which is the center of the axial center portion 71, is parallel to the rotation axis Ax1. Axial centers Ax2 of the plurality of crankshafts 7A, 7B, and 7C are arranged at equal intervals in the circumferential direction on a virtual circle centered on the rotation axis Ax1. Each eccentric portion 72 has a disk shape, with at least the outer circumferential surface being a perfect circle in plan view. The center (central axis) C0 of each eccentric portion 72 is parallel to the rotation axis Ax1, and is disposed at a position deviated from the rotation axis Ax1 in the radial direction. Here, the distance ΔL0 between the axial center Ax2 and the center C0 (see FIGS. 5 and 6) is the amount of eccentricity of the eccentric portion 72 with respect to the axial center portion 71. The eccentric portion 72 has a flange shape that protrudes from the outer peripheral surface of the shaft center portion 71 over the entire circumference at the central portion of the shaft center portion 71 in the longitudinal direction (axial direction). According to the above-described configuration, in each of the crankshafts 7A, 7B, and 7C, the eccentric portion 72 moves eccentrically as the shaft center portion 71 rotates (rotates) about the axis Ax2.

In this basic configuration, the shaft center portion 71 and the two eccentric portions 72 are integrally formed of one metal member, thereby realizing seamless crankshafts 7A, 7B, and 7C. The crankshafts 7A, 7B, and 7C having such shapes are combined with the eccentric bearing 5 and the planetary gear 3. Therefore, when the crankshafts 7A, 7B, 7C rotate with the planetary gear 3 combined with the eccentric bearing 5 and the crankshafts 7A, 7B, 7C, the planetary gear 3 swings around the rotation axis Ax1.

The eccentric bearing 5 has a plurality of rolling elements 51 (see FIG. 4), absorbs the rotational component of the rotation of the crankshafts 7A, 7B, and 7C, and absorbs the rotational component of the rotation of the crankshafts 7A, 7B, and 7C. This is a component for transmitting only the rotation of the crankshafts 7A, 7B, and 7C, that is, the swinging components (revolution components) of the crankshafts 7A, 7B, and 7C, to the planetary gear 3. The plurality of rolling elements 51 are arranged between the outer circumferential surface of the eccentric portion 72 of each crankshaft 7A, 7B, 7C and the inner circumferential surface of each opening 33 of the planetary gear 3. That is, the eccentric portions 72 of each of the crankshafts 7A, 7B, and 7C function as an inner ring of the eccentric bearing 5, and the inner peripheral surface of each opening 33 of the planetary gear 3 functions as an outer ring of the eccentric bearing 5.

When each crankshaft 7A, 7B, 7C rotates in a state where the eccentric bearing 5 and the plurality of crankshafts 7A, 7B, 7C are combined with the planetary gear 3, the eccentric bearing 5 rotates around the axis Ax2 ( eccentric movement). At this time, the rotational components of the crankshafts 7A, 7B, and 7C are absorbed by the eccentric bearings 5. Therefore, in the planetary gear 3, the rotation of the crankshafts 7A, 7B, 7C excluding the rotational components of the crankshafts 7A, 7B, 7C, that is, the swinging components of the crankshafts 7A, 7B, 7C ( Only the orbital component) will be transmitted. Therefore, when the crankshafts 7A, 7B, 7C rotate with the planetary gear 3 combined with the eccentric bearing 5 and the crankshafts 7A, 7B, 7C, the planetary gear 3 swings around the rotation axis Ax1.

In the gear device 1 configured as described above, a rotational force as an input is applied to the input shaft 500, and the input shaft 500 rotates around the rotation axis Ax1, so that the planetary gear 3 swings around the rotation axis Ax1. (revolution). At this time, the planetary gear 3 is inscribed with the internal gear 2 inside the internal gear 2, and swings with a part of the external tooth 31 meshing with a part of the internal tooth 21, so that the internal gear 21 and the external teeth 31 move in the circumferential direction of the internal gear 2. As a result, relative rotation occurs between the planetary gear 3 and the internal gear 2 according to the difference in the number of teeth between the two gears (the internal gear 2 and the planetary gear 3). The rotation (rotation component) of the planetary gear 3, excluding the oscillation component (revolution component) of the planetary gear 3, is transmitted to the pair of carriers 18, 19 by the plurality of crankshafts 7A, 7B, 7C. . As a result, rotational output is obtained from the pair of carriers 18 and 19, which is reduced at a relatively high reduction ratio 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 basic configuration, 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 formula 1.

R1=V2/(V1-V2) (Formula 1)
In short, the smaller the difference in the number of teeth (V1-V2) between the internal gear 2 and the planetary gear 3, the larger the reduction ratio R1 becomes. As an example, since the number of teeth V1 of the internal gear 2 is "72", the number of teeth V2 of the planetary gear 3 is "70", and the difference in the number of teeth (V1-V2) is "2", from the above formula 1, The reduction ratio R1 becomes "35". In this case, when viewed from the input side of the rotating shaft Ax1, each crankshaft 7A, 7B, 7C rotates clockwise once (360 degrees) around the axis Ax2 of the shaft center portion 71 (see FIGS. 5 and 6). When rotated, the pair of carriers 18 and 19 rotate counterclockwise around the rotation axis Ax1 by a difference in the number of teeth of "2" (that is, about 10.3 degrees).

According to the gear device 1 according to the present basic configuration, such a high reduction ratio R1 can be realized by the combination of the internal gear 2 and the planetary gear 3. Furthermore, an appropriate reduction ratio can be achieved between the input gear 501 and the plurality of crankshaft gears 502A, 502B, 502C depending on the number of teeth of the input gear 501 and the crankshaft gears 502A, 502B, 502C. . As a result, the gear device 1 as a whole can achieve a high reduction ratio.

Further, the gear device 1 only needs to include at least an internal gear 2, a planetary gear 3, crankshafts 7A, 7B, and 7C, and a pair of carriers 18 and 19. For example, as shown in FIG. As shown, a spacer 11 may be further provided. The spacer 11 is arranged between the pair of planetary gears 3 (first planetary gear 301 and second planetary gear 302) in a direction (axial direction) parallel to the rotation axis Ax1.

(Reference example 1)
As shown in FIGS. 7 to 14, the internally meshing planetary gear device 1A (hereinafter also simply referred to as "gear device 1A") according to this reference example has a basic configuration mainly around the crankshafts 7A, 7B, and 7C. This is different from the gear device 1 according to the configuration. Hereinafter, configurations similar to the basic configuration will be given the same reference numerals and descriptions will be omitted as appropriate. FIG. 7 is a schematic cross-sectional view of the gear device 1A. FIG. 8 is a schematic diagram of the gear device 1A viewed from the output side of the rotating shaft Ax1. FIG. 9 is a schematic perspective view of peripheral members of one crankshaft 7A. FIG. 10 is a schematic exploded perspective view of peripheral members of one crankshaft 7A. FIG. 11 is a schematic perspective view of one crankshaft 7A. FIG. 12 is an enlarged view of region Z1 in FIG. FIG. 13 is an enlarged view of region Z2 in FIG. FIG. 14 is an enlarged view of region Z1 in FIG. 13.

The gear device 1A according to this reference example further includes a plurality of oil seals 121, 122, etc., as shown in FIG. The oil seal 121 closes the gap between the case 10 and the outer peripheral surface of the output side carrier 19. The oil seal 122 closes a central hole 193 formed in the center of the output carrier 19. A space sealed by the plurality of oil seals 121, 122, etc. constitutes a lubricant holding space 17. The lubricant holding space 17 includes a space between the inner ring 61 and the outer ring 62 of the bearing member 6. Furthermore, a plurality of outer pins 23, a planetary gear 3, a pair of rolling bearings 41 and 42, an eccentric bearing 5, and the like are housed in the lubricant holding space 17.

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

The gear device 1A according to this reference example further includes a pair of covers 13 and 14 attached to both sides of the pair of carriers 18 and 19 in the axial direction. When distinguishing the pair of covers 13 and 14 from each other, the cover 13 located on the input side of the rotation axis Ax1 (right side in FIG. 7) is referred to as the "input side cover 13", and In this case, the cover 14 located on the left side will be referred to as the "output side cover 14." In this reference example, the material of the pair of covers 13 and 14 is a metal such as stainless steel, cast iron, carbon steel for mechanical structures, or chromium molybdenum steel, or a heat-treated metal.

The input side cover 13 is formed into a disk shape centered on the rotation axis Ax1. Here, at least the outer circumferential surface of the input side cover 13 is a perfect circle centered on the rotation axis Ax1 in plan view (as viewed from one side in the axial direction). The outer diameter of the input side cover 13 is one size smaller than the outer diameter of the input side carrier 18. The input side cover 13 is attached to the input side carrier 18 from the outside, that is, from the side opposite to the planetary gear 3 when viewed from the input side carrier 18 (the right side in FIG. 7).

The output side cover 14 is formed into a disk shape centered on the rotation axis Ax1. Here, at least the outer circumferential surface of the output side cover 14 is a perfect circle centered on the rotation axis Ax1 in plan view (as viewed from one side in the axial direction). The outer diameter of the output side cover 14 is one size smaller than the outer diameter of the output side carrier 19. The output side cover 14 is attached to the output side carrier 19 from the outside, that is, from the side opposite to the planetary gear 3 when viewed from the output side carrier 19 (left side in FIG. 7).

Here, the pair of covers 13 and 14 are removably attached to the pair of carriers 18 and 19. That is, the input side cover 13 is removably attached to the input side carrier 18, and the output side cover 14 is removably attached to the output side carrier 19. In this reference example, as an example, each cover 13, 14 is attached to each carrier 18, 19 with a plurality of fixing bolts 142 (see FIG. 8). Therefore, each cover 13, 14 can be removed from each carrier 18, 19 by removing the plurality of fixing bolts 142.

Here, in the output side cover 14 of the pair of covers 13 and 14, as shown in FIG. 8, a plurality of transparent A hole 141 is provided. That is, the output side carrier 19 is provided with a plurality of mounting holes 194 (female threads) for fixing a mating member. Therefore, also in the output side cover 14 attached to the outside of the output side carrier 19, a plurality of through holes 141 are formed at positions corresponding to the plurality of attachment holes 194. In particular, when transmitting high torque from the output side carrier 19 to a mating member, the number of mounting holes 194 and through holes 141 increases. Further, the arrangement and number of the mounting holes 194 and the through holes 141 need to be matched to the mating member.

On the other hand, shaft holes 131 (see FIG. 7) through which the crankshafts 7A, 7B, and 7C pass are provided only in the input-side cover 13 of the pair of covers 13 and 14. That is, the input side cover 13 is provided with a plurality of shaft holes 131 corresponding to the plurality of crankshafts 7A, 7B, and 7C. The shaft center portion 71 of each crankshaft 7A, 7B, and 7C is inserted into each shaft hole 131. Here, the inner diameter of each shaft hole 131 is set to be one size larger than the outer diameter of the shaft center portion 71 so that the shaft center portion 71 does not come into contact with the inner circumferential surface of the shaft hole 131 .

By the way, to explain in more detail the configuration around each of the crankshafts 7A, 7B, and 7C, the gear device 1A according to this reference example employs a configuration as shown in FIGS. 9 to 11. Here, the crankshaft 7A will be explained as an example, but a similar configuration is also adopted for the crankshafts 7B and 7C.

That is, the crankshaft 7A has a flange portion 73 between two eccentric portions 72 in the axial direction along the axis Ax2. The flange portion 73 has a disk shape centered on the axis Ax2, and at least the outer peripheral surface is a perfect circle in plan view. The outer diameter of the flange portion 73 is set to be one size larger than the outer diameter of the eccentric portion 72, and the flange portion 73 has a flange shape that protrudes from the outer peripheral surface of the eccentric portion 72 over the entire circumference. In this reference example, as an example, the shaft center portion 71, the two eccentric portions 72, and the flange portion 73 are seamlessly integrated.

Here, since the crankshaft 7A has two eccentric parts 72 with respect to one shaft center part 71, it has step parts 70 at at least two places in the axial direction. That is, the diameter of the crankshaft 7A is not uniform over its entire length, but changes at least between the shaft center portion 71 and each eccentric portion 72, so that two step portions 70 are generated in this portion. In other words, the end surface of each eccentric portion 72 facing toward the outside in the axial direction (that is, the side opposite to the flange portion 73) becomes the step portion 70, respectively.

In this reference example, the shaft center portion 71 of the crankshaft 7A has a smaller diameter at both ends in the axial direction than at the center portion in the axial direction. Therefore, a stepped portion 70 is generated at each portion where the diameter of the shaft center portion 71 changes. As a result, the crankshaft 7A has stepped portions 70 at four locations in the axial direction. Here, when distinguishing each stepped portion 70, from the input side (right side in FIG. 7) of the rotation axis Ax1, they are respectively defined as a first stepped portion 701, a second stepped portion 702, a third stepped portion 703, This is referred to as a fourth stepped portion 704. That is, the first step portion 701 and the second step portion 702 are end faces facing the input side of the rotation axis Ax1, and the third step portion 703 and the fourth step portion 704 are the end faces facing the input side of the rotation axis Ax1. This is the end face facing the output side. An end of the shaft center portion 71 on the input side of the rotating shaft Ax1 further than the first stepped portion 701 constitutes a mounting portion 74 for mounting the crankshaft gear 502A.

A pair of rolling bearings 41, 42, a pair of eccentric bearings 5, washers 81 to 85, and a retaining ring 86 are combined with such a crankshaft 7A. That is, the eccentric bearings 5 are respectively mounted on the two eccentric parts 72 of the crankshaft 7A. Further, a pair of rolling bearings 41 and 42 are installed in the shaft center portion 71 of the crankshaft 7A at positions on both sides of the two eccentric portions 72 in the axial direction. Furthermore, a groove 75 into which a retaining ring 86 is fitted is provided at the end of the shaft center portion 71 of the crankshaft 7A on the output side (left side in FIG. 7) of the rotating shaft Ax1 further than the fourth stepped portion 704. It is formed. Therefore, a retaining ring 86 is attached to the output side end of the rotating shaft Ax1 in the shaft center portion 71.

Here, the washer 81, eccentric bearing 5, washer 82, and rolling bearing 41 are arranged in this order from the flange part 73 side on the input side (right side in FIG. 7) of the rotation axis Ax1 when viewed from the flange part 73. will be installed on the On the other hand, a washer 83, an eccentric bearing 5, a washer 84, a rolling bearing 42, a washer 85, and a retaining ring 86 are placed on the output side (left side in FIG. 7) of the rotating shaft Ax1 when viewed from the flange portion 73. They are installed so that they are lined up in this order. Therefore, on the input side of the rotation axis Ax1 when viewed from the flange portion 73, a washer 81 is interposed between the flange portion 73 and the eccentric bearing 5, and a washer 82 is interposed between the eccentric bearing 5 and the rolling bearing 41. intervene. On the output side of the rotating shaft Ax1 when viewed from the flange portion 73, a washer 83 is interposed between the flange portion 73 and the eccentric bearing 5, and a washer 84 is interposed between the eccentric bearing 5 and the rolling bearing 42. . Furthermore, the rolling bearing 42 comes into contact with the retaining ring 86 via the washer 85, thereby restricting movement of the rotating shaft Ax1 toward the output side.

More specifically, the eccentric portion 72 is inserted into each of the washers 81 and 83, and the shaft center portion 71 is inserted into each of the washers 82 and 84. Here, a washer 82 is interposed between the second step portion 702 of the crankshaft 7A and the rolling bearing 41. On the other hand, a washer 84 is interposed between the third step portion 703 of the crankshaft 7A and the rolling bearing 42. Furthermore, a washer 85 is interposed between the fourth stepped portion 704 of the crankshaft 7A and the retaining ring 86. These washers 81 to 85 are made of metal, for example, and function as bearing rings (bearing discs) that reduce friction between the two members.

By the way, as shown in FIG. 12, the gear device 1A according to this reference example includes a regulating structure 9 that regulates the movement of each crankshaft 7A, 7B, and 7C in the axial direction. That is, in the gear device 1A according to this reference example, the regulation structure 9 regulates the axial movement of the crankshafts 7A, 7B, and 7C. The "axial direction" in the present disclosure means a direction along the axis Ax2 of the crankshafts 7A, 7B, and 7C, particularly a direction (thrust direction) parallel to the axis Ax2 of the crankshafts 7A, 7B, and 7C. In addition, "restricting movement" as used in this disclosure means imposing some kind of restriction on movement, and includes not only completely prohibiting movement, but also limiting the range of movement or making it difficult to move. including. That is, in this reference example, the movement of the crankshafts 7A, 7B, 7C is restricted in the axial direction along the axis Ax2 of the crankshafts 7A, 7B, 7C due to the provision of the restriction structure 9. become.

In this reference example, as an example, the regulation structure 9 prohibits movement of the crankshafts 7A, 7B, and 7C in both the one (input side of the rotation axis Ax1) and the other (output side of the rotation axis Ax1) in the axial direction. That's it. That is, in the example of FIG. 8, the regulation structure 9 prohibits the pair of carriers 18 and 19 from moving the crankshafts 7A, 7B, and 7C to the right in the figure and to the left in the figure. do. Thereby, the positions of the crankshafts 7A, 7B, and 7C in the axial direction are positioned at regular positions (with respect to the pair of carriers 18 and 19).

Specifically, in this reference example, the regulation structure 9 includes a pair of covers 13 and 14 attached to both sides of a pair of carriers 18 and 19 in the axial direction. In short, the gear device 1A uses the input side cover 13 and the output side cover 14 described above to restrict movement of each crankshaft 7A, 7B, and 7C in the axial direction. In particular, the gear device 1A according to this reference example includes a first regulating structure 91 as the regulating structure 9 that regulates the movement of the crankshafts 7A, 7B, and 7C in one axial direction (rightward in FIG. 8); and a second regulating structure 92 that regulates the movement of the crankshafts 7A, 7B, and 7C to the other direction (to the left in FIG. 8).

Here, the input side cover 13 is included in the first regulating structure 91, and receives a force F1 acting from the crankshafts 7A, 7B, and 7C in one axial direction (rightward in FIG. 8). The movement of the crankshafts 7A, 7B, and 7C in one direction is restricted. On the other hand, the output side cover 14 is included in the second regulation structure 92 and receives a force F2 that acts from the crankshafts 7A, 7B, and 7C toward the other axial direction (leftward in FIG. 8). The movement of the crankshafts 7A, 7B, and 7C to the other side is restricted.

More specifically, the first regulation structure 91 includes the input side cover 13 and the first stepped portions 701 of the crankshafts 7A, 7B, and 7C. According to the first regulation structure 91, the rotation of the crankshafts 7A, 7B, and 7C is restricted around the shaft hole 131 on the surface facing the output side (left side in FIG. 8) of the rotation axis Ax1 of the input side cover 13. The movement of the crankshafts 7A, 7B, and 7C in one direction in the axial direction (rightward in FIG. 8) is restricted by contacting the first stepped portion 701 facing the input side (rightward in FIG. 8) of the shaft Ax1. be done. In other words, the first step portion 701 of the crankshafts 7A, 7B, 7C comes into contact with the input side cover 13 attached to the input side carrier 18, so that the crankshafts 7A, 7B, 7C are moved in one direction in the axial direction. Movement is prohibited.

The second regulation structure 92 includes an output side cover 14 and an end surface 76 on the output side of the rotation axis Ax1 of the crankshafts 7A, 7B, and 7C. According to such a second regulation structure 92, the output side (of the rotation axis Ax1 of the crankshafts 7A, 7B, 7C) is attached to the surface of the output side cover 14 facing the input side (the right side in FIG. 8) of the rotation axis Ax1. When the end surfaces 76 facing toward the left side in FIG. 8 come into contact with each other, movement of the crankshafts 7A, 7B, and 7C in the other axial direction (leftward in FIG. 8) is restricted. In other words, when the end surfaces 76 of the crankshafts 7A, 7B, and 7C come into contact with the output side cover 14 attached to the output side carrier 19, movement of the crankshafts 7A, 7B, and 7C in the other direction in the axial direction is prohibited. Ru.

Here, in the regulation structure 9, the end surfaces (the second stepped portion 702 and the third stepped portion 703) of the eccentric portions 72 of the crankshafts 7A, 7B, and 7C are in contact with the pair of covers 13 and 14. It is a part other than that. That is, the regulating structure 9 is located on the axially outer side of the step portions 702 and 703 formed of the end surfaces of the eccentric portions 72 among the crankshafts 7A, 7B, and 7C, and is located on the axially outward facing end surfaces (first The axial movement of the crankshafts 7A, 7B, and 7C is restricted by contacting the stepped portion 701 or end surface 76) of the crankshafts 7A, 7B, and 7C. Therefore, the stepped portions 702, 703 formed from the end surfaces of the eccentric portion 72 do not generate friction due to contact with the pair of covers 13, 14, etc., and wear and the like of the stepped portions 702, 703 can be reduced.

By the way, the gear device 1A according to this reference example includes an internal gear 2, a planetary gear 3, crankshafts 7A, 7B, 7C, and a pair of carriers 18, 19, and makes the planetary gear 3 swing. This causes the planetary gear 3 to rotate relative to the internal gear 2. The internal gear 2 includes an annular gear main body 22 and a plurality of outer pins 23 that are rotatably held in a plurality of inner circumferential grooves 223 formed in an inner circumferential surface 221 of the gear main body 22 and constitute internal teeth 21. and has. The planetary gear 3 has external teeth 31 that partially mesh with the internal teeth 21. The crankshafts 7A, 7B, and 7C have stepped portions 70 at at least two locations in the axial direction along the axis Ax2, and swing the planetary gear 3 by rotating around the axis Ax2. The pair of carriers 18 and 19 are arranged on both sides of the planetary gear 3 in the axial direction, and rotatably support the crankshafts 7A, 7B, and 7C. Here, as shown in FIG. 13, between the stepped portion 70 and the pair of carriers 18 and 19, lubrication paths S1 through which lubricant passes are formed.

That is, in this reference example, a lubrication path S1 is secured between the stepped portion 70 and the pair of carriers 18 and 19. By securing such a lubrication path S1, in the gear device 1A, the lubricant can be circulated through the lubrication path S1, and the lubrication state of the pair of rolling bearings 41, 42, the pair of eccentric bearings 5, etc. is maintained. It can be improved. In FIG. 13, the manner in which the lubricant flows (circulates) through the lubricant path S1 is conceptually represented by broken line arrows.

In this reference example, the lubrication path S1 is formed within a lubricant holding space 17 into which lubricant is injected. By forming such a lubrication path S1, "lubricant shortage" where lubricant is insufficient or depleted is less likely to occur around the crankshafts 7A, 7B, and 7C, and more than a certain amount of lubricant is always supplied. That will happen. Moreover, compared to a configuration in which the lubricant stagnates in a fixed position, the lubricant is circulated through the lubrication path S1, so that the lubricant is replaced at any time around the crankshafts 7A, 7B, and 7C. It is possible to suppress deterioration of the lubricant.

Therefore, the lubrication state of the pair of rolling bearings 41, 42, the pair of eccentric bearings 5, etc. is improved, and poor lubrication is less likely to occur. Therefore, even when the gear device 1A is used for a long period of time, loss due to friction can be reduced and the life of the gear device 1A can be easily extended. In short, the gear device 1A according to this reference example is unlikely to suffer from a decrease in reliability, especially when used for a long period of time, which in turn leads to improved transmission efficiency, longer life, and higher performance of the gear device 1A. .

Here, in this reference example, the lubrication path S1 includes a radial path S11 through which the lubricant passes in the radial direction orthogonal to the axial direction. That is, as shown in FIG. 14, which is a schematic enlarged view of region Z1 in FIG. It includes a radial passage S11 through which lubricant passes. Thereby, when the crankshafts 7A, 7B, and 7C rotate, the lubricant is passed in the radial direction by centrifugal force, so that the lubricant can be efficiently circulated through the lubrication path S1.

Further, in this reference example, there is a gap in the axial direction between the stepped portions 702, 703 and at least one of the pair of carriers 18, 19, and the lubrication path S1 fills the gap. include. In this reference example, as described above, at least the step portions 702 and 703 formed from the end faces of the eccentric portion 72 are not used as the regulating structure 9, so that the step portions 702 and 703 are connected to the pair of carriers 18 and 19. A gap is provided between them, and this gap can be a part of the lubrication path S1. In this reference example, as an example, gaps generated between the step portions 702 and 703 and both of the pair of carriers 18 and 19 constitute a part of the lubrication path S1.

Furthermore, this reference example further includes plate-shaped parts (washers 82, 84) disposed between the stepped portion 70 and the pair of carriers 18, 19. The lubrication path S1 includes a groove 80 (see FIG. 10) formed on the surface of the plate-shaped component (washer 82, 84) facing the carriers 18, 19. That is, as shown in FIG. 10, in the washers 81 to 84, grooves 80 extending in the radial direction are formed on the surfaces facing outward in the axial direction (toward the carriers 18 and 19). Here, it is preferable that a plurality of grooves 80 are formed for each of the washers 81 to 84, and in this reference example, as an example, four grooves 80 are formed for each of the washers 81 to 84. The four grooves 80 are arranged at equal intervals in the circumferential direction of each washer 81-84. By providing such a groove 80, the lubricant will flow through the groove 80, and the groove 80 will be included in the lubrication path S1. As a result, the cross-sectional area of the lubrication path S1 can be increased compared to the case where the groove portion 80 is not provided, and the lubricant can circulate more easily.

In addition, when a plurality of crankshafts 7A, 7B, 7C are provided as in this reference example, a connection that connects a plurality of lubrication paths S1 formed around these plurality of crankshafts 7A, 7B, 7C, respectively. Preferably, a path S2 is provided. Thereby, the lubricant can be circulated between the plurality of crankshafts 7A, 7B, and 7C, and the lubricant can be circulated throughout the gear device 1A, so that further improvement of the lubrication state can be expected.

Specifically, as shown in FIG. 7, grooves 133 and 143 are formed in each of the pair of covers 13 and 14 on the surface facing inward in the axial direction (the surface on the planetary gear 3 side). The grooves 133 and 143 are annular grooves centered around the rotation axis Ax1, which are formed to pass through the rolling bearings 41 and 42 that support each of the plurality of crankshafts 7A, 7B, and 7C in a plan view. (See Figure 8). Therefore, the lubrication path S1 including a plurality of (three in this case) rolling bearings 41 is connected by a connection path S2 formed by the groove 133 of the input side cover 13. Similarly, a lubrication path S1 including a plurality of (three in this case) rolling bearings 42 is connected by a connection path S2 formed by a groove 143 in the output side cover 14.

Further, the gear device 1A according to this reference example includes an input gear 501 that rotates around the rotation axis Ax1, and a plurality of crankshaft gears 502A, 502B, and 502C. The plurality of crankshaft gears 502A, 502B, and 502C are arranged around the input gear 501 so as to mesh with the input gear 501, and rotate in synchronization with each other when the input gear 501 rotates. A plurality of crankshafts 7A, 7B, and 7C are provided in one-to-one correspondence with a plurality of crankshaft gears 502A, 502B, and 502C. The plurality of crankshafts 7A, 7B, and 7C rotate together with the plurality of crankshaft gears 502A, 502B, and 502C, and swing the planetary gear 3 about the rotation axis Ax1.

In this manner, in the distribution type gear device 1A having the plurality of crankshafts 7A, 7B, 7C, the axial movement of the plurality of crankshafts 7A, 7B, 7C can be restricted. Furthermore, by circulating the lubricant around the plurality of crankshafts 7A, 7B, and 7C, it is possible to improve the lubrication state.

As shown in FIG. 15, the gear device 1A according to this reference example constitutes a robot joint device 200 together with a first member 201 and a second member 202. In other words, the robot joint device 200 according to this reference example includes the gear device 1A, the first member 201, and the second member 202. The first member 201 is fixed to the gear body 22. The second member 202 rotates relative to the first member 201 as the pair of planetary gears 3 rotates relative to the internal gear 2 . FIG. 15 is a schematic cross-sectional view of the robot joint device 200. Moreover, in FIG. 15, the first member 201, the second member 202, and the drive source 101 are schematically shown.

The robot joint device 200 configured in this manner functions as a joint device by the first member 201 and the second member 202 rotating relatively around the rotation axis Ax1. Here, by driving the input shaft 500 of the gear device 1A with the drive source 101, the first member 201 and the second member 202 rotate relative to each other. At this time, the rotation (input rotation) generated by the drive source 101 is reduced at a relatively high reduction ratio in the gear device 1A, and drives the first member 201 or the second member 202 with relatively high torque. That is, the first member 201 and the second member 202 connected by the gear device 1A can bend and extend around the rotation axis Ax1.

The robot joint device 200 is used, for example, in a robot such as a horizontal multi-joint robot (SCARA type robot). Further, 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. Furthermore, the gear device 1A according to this reference example is not limited to the joint device 200 for a robot, and may be used, for example, as a wheel device such as an in-wheel motor in a vehicle such as an automated guided vehicle (AGV: Automated Guided Vehicle). good.

<Modified example>
Reference Example 1 is only one of various reference examples of the present disclosure. Reference Example 1 can be modified in various ways depending on the design, etc., as long as the objective of the present disclosure can be achieved. Furthermore, all the drawings referred to in this disclosure are schematic drawings, and the ratios of the sizes and thicknesses of each component in the drawings do not necessarily reflect the actual dimensional ratios. . Modifications of Reference Example 1 will be listed below. The modified examples described below can be applied in combination as appropriate.

The number of crankshafts 7A, 7B, 7C is not limited to "3", but may be 2 or 4 or more. Furthermore, if there is only one crankshaft, an eccentric oscillation type internally meshing planetary gear device, in which the rotating shaft Ax1 and the crankshaft axis Ax2 coincide with each other, is realized instead of the distribution type. In this case, the planetary gear 3 swings by driving the crankshaft, and the pair of carriers 18 and 19 can be rotated relative to the gear body 22 around the rotation axis Ax1.

Further, in Reference Example 1, the gear device 1A has two types of planetary gears 3, but the gear device 1A may include three or more planetary gears 3. For example, when the gear device 1A includes three planetary gears 3, it is preferable that these three planetary gears 3 are 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 of these three planetary gears 3 are in the same phase, and the remaining one planetary gear 3 has a rotation angle of 180 degrees around the rotation axis Ax1. They may be arranged with a phase difference.

Further, the bearing member 6 may be a cross roller bearing, a deep groove ball bearing, a four-point contact ball bearing, or the like.

In addition, the number of teeth of the input gear 501, the number of teeth of the crankshaft gears 502A, 502B, 502C, the number of external pins 23 (the number of internal teeth 21), the number of external teeth 31, etc. explained in Reference Example 1 are as follows. , is just an example and can be modified as appropriate.

Further, the eccentric bearing 5 is not limited to a roller bearing, and may be, for example, a deep groove ball bearing, an angular contact 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 output the relative rotation between the inner ring 61 and the outer ring 62 of the bearing member 6, and the rotational force of the inner ring 61 (input side carrier 18 and output side carrier 19) is It is not limited to the configuration that is extracted as output. For example, the rotational force of the outer ring 62 (case 10) rotating relative to the inner ring 61 may be extracted as an output.

Further, in Reference Example 1, the output side end face 76 of the rotation axis Ax1 of the crankshafts 7A, 7B, and 7C is in direct contact with the output side cover 14, but the configuration is not limited to this, and the end face 76 and the output side For example, a plate-shaped component such as a shim member may be arranged between the side cover 14 and the side cover 14 . In this case, when attaching the output side cover 14, the gap between the end face 76 and the output side cover 14 in the axial direction can be adjusted by adjusting the thickness (and/or number) of the plate-like parts. , the "play" in the axial direction of the crankshafts 7A, 7B, and 7C can be adjusted. Furthermore, the plate-shaped component functions as a bearing ring (bearing disk) that reduces friction between the end face 76 and the output side cover 14.

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

(Embodiment 1)
As shown in FIG. 16, the internal meshing planetary gear device 1B (hereinafter also simply referred to as "gear device 1B") according to the present embodiment includes an input side cover 13 (see FIG. 7) and an output side cover 14 (see FIG. 7). The gear device 1A is different from the gear device 1A according to Reference Example 1 in that the reference example 1) is omitted. Hereinafter, the same configurations as those in Reference Example 1 will be given the same reference numerals and the description will be omitted as appropriate. FIG. 16 is a schematic cross-sectional view of the gear device 1B.

In the gear device 1B according to this embodiment, the axial movement of each crankshaft 7A, 7B, 7C is restricted by the flange portion 73 of each crankshaft 7A, 7B, 7C. That is, the gear device 1B includes an internal gear 2, a pair of planetary gears 3, crankshafts 7A, 7B, 7C, a pair of carriers 18, 19, and a regulating structure 9. By swinging, the pair of planetary gears 3 are rotated relative to the internal gear 2. The internal gear 2 includes an annular gear main body 22 and a plurality of outer pins 23 that are rotatably held in a plurality of inner circumferential grooves 223 formed in an inner circumferential surface 221 of the gear main body 22 and constitute internal teeth 21. and has. The pair of planetary gears 3 have external teeth 31 that partially mesh with the internal teeth 21. The crankshafts 7A, 7B, and 7C swing the pair of planetary gears 3 by rotating around the axis Ax2. The pair of carriers 18 and 19 are arranged on both sides of the pair of planetary gears 3 in the axial direction along the axis Ax2, and rotatably support the crankshafts 7A, 7B, and 7C. The regulating structure 9 regulates the movement of the crankshafts 7A, 7B, and 7C relative to the pair of planetary gears 3 in the axial direction. Here, as shown in FIG. 16, the regulation structure 9 has a flange portion 73 located at at least one location in the axial direction of the crankshafts 7A, 7B, and 7C and arranged to be sandwiched between the pair of planetary gears 3. have

As described above, in this embodiment, the regulation structure 9 includes the flange portions 73 of the crankshafts 7A, 7B, and 7C, and the flange portions 73 are connected to the flange portions 73 of the pair of planetary gears 3 (the first planetary gear 301 and the second planetary gear 302). By sandwiching them between them, movement of the crankshafts 7A, 7B, and 7C in the axial direction with respect to the pair of planetary gears 3 is restricted. In other words, in the gear device 1B, instead of the input side cover 13 and the output side cover 14, the flange portions 73 provided on the crankshafts 7A, 7B, and 7C are used to control the axial direction of the crankshafts 7A, 7B, and 7C. Movement can be regulated. As a result, the gear device 1B does not use tapered roller bearings or the pair of covers 13, 14 attached to the pair of carriers 18, 19, and has a relatively simple configuration, but the crankshafts 7A, 7B, It is possible to restrict the movement of 7C in the axial direction. Therefore, according to the configuration of this embodiment, it is possible to reduce rattling, transmission loss, etc. caused by axial movement of the crankshafts 7A, 7B, and 7C.

Moreover, the gear device 1B according to the present embodiment has the following advantages compared to the gear device 1A according to Reference Example 1. That is, the depth of the plurality of attachment holes 194 provided in the output side carrier 19 can be ensured to be deep by the thickness of the output side cover 14, and it is easy to improve the attachment strength of the mating member to the output side carrier 19. Furthermore, since the output side cover 14 provided with the plurality of through holes 141 corresponding to the plurality of attachment holes 194 is omitted, there is no need to adjust the arrangement and number of the through holes 141 according to the mating member. Further, since the fixing bolts 142 (see FIG. 8) for attaching the output side cover 14 to the output side carrier 19 are not required, the attachment holes 194 can be provided without interfering with the fixing bolts 142.

Specifically, in this embodiment, the flange portion 73 provided between the two eccentric portions 72 in the axial direction of each crankshaft 7A, 7B, and 7C is expanded (expanded) in the radial direction compared to Reference Example 1. diameter). The outer diameter of the flange portion 73 is set to be larger than at least the inner diameter of the opening 33 of the planetary gear 3. Here, as an example, the outer diameter of the flange portion 73 is larger than the inner diameter of the bearing hole 195 into which the rolling bearing 42 in the output side carrier 19 is inserted. The pair of planetary gears 3 position the crankshafts 7A, 7B, and 7C in the axial direction by sandwiching the enlarged flange portion 73 from both sides in the axial direction.

Here, the flange portion 73 is in contact with the periphery of the opening 33 on the output side (left side in FIG. 16) surface of the rotation axis Ax1 in the first planetary gear 301, and on the input side of the rotation axis Ax1 in the second planetary gear 302. It comes into contact with the periphery of the opening 33 on the surface (on the right side in FIG. 16). As a result, the flange portion 73 is sandwiched between the first planetary gear 301 and the second planetary gear 302, and the axial movement of each crankshaft 7A, 7B, and 7C is restricted. In this embodiment, washers 81 and 83 (see FIG. 12) on both sides of the flange portion 73 in the axial direction are omitted. Therefore, the flange portion 73 comes into direct contact with the planetary gear 3.

Further, the flange portion 73 is configured integrally with the crankshafts 7A, 7B, 7C, or is coupled to the crankshafts 7A, 7B, 7C so as to be in direct contact with the crankshafts 7A, 7B, 7C. . In this embodiment, the flange portion 73, the shaft center portion 71, and the two eccentric portions 72 are integrally formed of one metal member, thereby realizing seamless crankshafts 7A, 7B, and 7C. . Therefore, by sandwiching the flange portion 73 between the pair of planetary gears 3, the axial movement of the crankshafts 7A, 7B, and 7C can be reliably restricted.

Further, in this embodiment, the pair of planetary gears 3 are restricted from moving in the axial direction with respect to the pair of carriers 18 and 19. In other words, the pair of planetary gears 3 (first planetary gear 301 and second planetary gear 302) sandwiching the flange portion 73 are also positioned in the axial direction. Therefore, the movement of the flange portion 73 sandwiched between the pair of planetary gears 3 in the axial direction relative to the pair of carriers 18 and 19 is also restricted. Therefore, the crankshafts 7A, 7B, and 7C provided with the flange portions 73 are indirectly positioned in the axial direction with respect to the pair of carriers 18 and 19.

In particular, in this embodiment, the pair of planetary gears 3 directly or indirectly contact the outer ring 62 of the bearing member 6 held by the pair of carriers 18, 19, so that the pair of carriers 18, 19 is restricted from moving in the axial direction. That is, the movement of the pair of planetary gears 3 sandwiching the flange portion 73 in the axial direction is restricted not by the pair of carriers 18 and 19 but by the outer ring 62 of the bearing member 6. Since the outer ring 62 is held by the case 10 which rotates relatively to the pair of carriers 18 and 19, it is separate from the pair of carriers 18 and 19. Therefore, while restricting the axial movement of the pair of planetary gears 3, a gap is ensured between the pair of planetary gears 3 and the pair of carriers 18, 19, which becomes part of the lubrication path S1 through which the lubricant passes. It is possible to do so.

FIG. 17 is an enlarged schematic diagram of region Z1 in FIG. 16. As shown in FIG. 17, the first regulation structure 91 includes a flange portion 73, a first planetary gear 301, and an outer ring 62 of the first bearing member 601. According to the first regulation structure 91, the surface facing the output side (left side in FIG. 17) of the rotation axis Ax1 of the first planetary gear 301 has the input side (in FIG. 17 The movement of the crankshafts 7A, 7B, and 7C in one direction in the axial direction (rightward in FIG. 17) is restricted by the contact between the surfaces facing the right side. That is, the outer ring 62 of the first bearing member 601 receives the force F1 acting from the flange portion 73 in one direction in the axial direction (rightward in FIG. 17) through the first planetary gear 301. Movement of the crankshafts 7A, 7B, and 7C in one direction is prohibited.

The second regulation structure 92 includes a flange portion 73, a second planetary gear 302, and an outer ring 62 of the second bearing member 602. According to the second regulation structure 92, the surface facing the input side (right side in FIG. 17) of the rotation axis Ax1 of the second planetary gear 302 has the output side (in FIG. 17) of the rotation axis Ax1 of the flange portion 73. The movement of the crankshafts 7A, 7B, and 7C in the other axial direction (leftward in FIG. 17) is restricted by the surfaces facing toward the left side (left side) coming into contact with each other. In other words, the outer ring 62 of the second bearing member 602 receives the force F2 acting from the flange portion 73 toward the other axial direction (leftward in FIG. 17) through the second planetary gear 302. Movement of the crankshafts 7A, 7B, and 7C to the other side is prohibited.

By the way, in this embodiment, a lubrication path S1 is secured between the stepped portion 70 and the pair of carriers 18 and 19. By securing such a lubrication path S1, in the gear device 1B, the lubricant can be circulated through the lubrication path S1, and the lubrication state of the pair of rolling bearings 41, 42, the pair of eccentric bearings 5, etc. It can be improved. The lubrication path S1 is formed within the lubricant holding space 17 into which lubricant is injected. By forming such a lubrication path S1, "lubricant shortage" where lubricant is insufficient or depleted is less likely to occur around the crankshafts 7A, 7B, and 7C, and more than a certain amount of lubricant is always supplied. That will happen. Moreover, compared to a configuration in which the lubricant stagnates in a fixed position, the lubricant is circulated through the lubrication path S1, so that the lubricant is replaced at any time around the crankshafts 7A, 7B, and 7C. It is possible to suppress deterioration of the lubricant.

In short, in this embodiment, there is a gap in the axial direction between the stepped portions 702, 703 and at least one of the pair of carriers 18, 19, and the lubrication path S1 fills the gap. include. In this embodiment, as described above, at least the stepped portions 702 and 703 formed from the end faces of the eccentric portion 72 are not used as the regulating structure 9, so that the stepped portions 702 and 703 and the pair of carriers 18 and 19 are A gap is provided between them, and this gap can be a part of the lubrication path S1. In this embodiment, as an example, gaps generated between the step portions 702 and 703 and both of the pair of carriers 18 and 19 constitute a part of the lubrication path S1.

In this way, the crankshafts 7A, 7B, and 7C have stepped portions 702 and 703 at at least two locations in the axial direction. Between the step portions 702 and 703 and the pair of carriers 18 and 19, (first) lubrication paths S1 through which lubricant passes are formed, respectively. Therefore, the lubrication state of the pair of rolling bearings 41, 42, the pair of eccentric bearings 5, etc. is improved, and poor lubrication is less likely to occur. Therefore, even when the gear device 1B is used for a long period of time, loss due to friction can be reduced and the life of the gear device 1B can be easily extended. In particular, in a configuration in which each crankshaft 7A, 7B, 7C is supported by a pair of tapered roller bearings, loss due to friction becomes large, but in this embodiment, a pair of rolling bearings 41, 42 with improved lubrication conditions are used. Since each crankshaft 7A, 7B, 7C is supported, loss due to friction can be significantly reduced. In short, the gear device 1B according to the present embodiment is unlikely to suffer from a decrease in reliability even when used for a long period of time, which in turn leads to improved transmission efficiency, longer life, and higher performance of the gear device 1B. .

Further, the flange portion 73 only needs to be located at at least one location in the axial direction of the crankshafts 7A, 7B, 7C and disposed so as to be sandwiched between the pair of planetary gears 3. It may be arranged at a position in the middle of the shaft center portion 71 or the eccentric portion 72 in 7C. Furthermore, the flange portion 73 may be provided at two or more locations on each crankshaft 7A, 7B, and 7C.

The configuration of Embodiment 1 can be employed in appropriate combination with the various configurations (including modified examples) described in Reference Example 1.

(Embodiment 2)
As shown in FIG. 18, the internal meshing planetary gear device 1C (hereinafter also simply referred to as "gear device 1C") according to the present embodiment includes washers 81 and 83 provided on both sides of the flange portion 73 in the axial direction. This is different from the gear device 1B according to the first embodiment. Hereinafter, configurations similar to those in Embodiment 1 will be given the same reference numerals and descriptions will be omitted as appropriate. FIG. 18 is a schematic cross-sectional view of the main parts of the gear device 1C.

That is, the gear device 1C according to the present embodiment further includes plate-shaped parts (washers 81, 83) arranged between at least one of the pair of planetary gears 3 and the flange portion 73. In this embodiment, a washer 81 is interposed between the flange portion 73 and the eccentric bearing 5 on the input side of the rotation axis Ax1 when viewed from the flange portion 73, and a washer 81 is provided on the output side of the rotation axis Ax1 when viewed from the flange portion 73. In this case, a washer 83 is interposed between the flange portion 73 and the eccentric bearing 5. That is, the washers 81 and 83 as plate-shaped parts are arranged between both of the pair of planetary gears 3 and the flange portion 73. Thereby, the flange portion 73 indirectly contacts the planetary gear 3 via the washers 81 and 83. Since the washers 81 and 83 function as bearing rings (bearing rings) that reduce friction between the two members, the slippage between the flange portion 73 and the planetary gear 3 can be dispersed by the washers 81 and 83. .

Also in this embodiment, the regulation structure 9 includes the flange portions 73 of the crankshafts 7A, 7B, and 7C, and the flange portions 73 are connected to the pair of planetary gears 3 (the first planetary gear 301 and the By sandwiching it between the two planetary gears 302), the axial movement of the crankshafts 7A, 7B, and 7C with respect to the pair of planetary gears 3 is restricted. As a result, the gear device 1C does not use tapered roller bearings or the pair of covers 13, 14 attached to the pair of carriers 18, 19, and has a relatively simple configuration, but the crankshafts 7A, 7B, It is possible to restrict the movement of 7C in the axial direction. Therefore, according to the configuration of this embodiment, it is possible to reduce rattling, transmission loss, etc. caused by axial movement of the crankshafts 7A, 7B, and 7C.

Furthermore, a second lubrication path S3 through which lubricant passes is formed between at least one of the pair of planetary gears 3 and the flange portion 73. In other words, since the lubricant circulates between at least one of the planetary gears 3 and the flange portion 73, it is possible to further improve the lubrication state. In this embodiment, as an example, the second lubrication path S3 is a groove portion 80 (see FIG. (see). By providing the grooves 80 in the washers 81 and 83, the lubricant flows through the grooves 80, and the grooves 80 are included in the second lubrication path S3. As a result, the cross-sectional area of the second lubrication path S3 can be increased, and the lubricant can circulate more easily than in the case where the groove portion 80 is not provided.

The configuration of Embodiment 2 can be employed in appropriate combination with the various configurations (including modified examples) described in Reference Example 1 or Embodiment 1.

(Embodiment 3)
As shown in FIG. 19, the internal meshing planetary gear device 1D (hereinafter also simply referred to as "gear device 1D") according to the present embodiment includes washers 81 and 83 provided on both sides of the flange portion 73 in the axial direction. This is different from the gear device 1B according to the first embodiment. Hereinafter, configurations similar to those in Embodiment 1 will be given the same reference numerals and descriptions will be omitted as appropriate. FIG. 19 shows the peripheral structure of the crankshafts 7A, 7B, and 7C, and is a schematic perspective view with the input shaft 500 pulled out to the input side of the rotating shaft Ax1.

First, as a premise, the gear device 1D according to the present embodiment is an eccentric oscillation type internally meshing planetary gear device, which is called a distribution type, as in the first and second embodiments. That is, as shown in FIG. 19, the gear device 1D includes an input gear 501 that rotates around a rotation axis Ax1, and a plurality of crankshaft gears 502A, 502B, and 502C. The plurality of crankshaft gears 502A, 502B, and 502C are arranged around the input gear 501 so as to mesh with the input gear 501, and rotate in synchronization with each other when the input gear 501 rotates. A plurality of crankshafts 7A, 7B, and 7C are provided in one-to-one correspondence with a plurality of crankshaft gears 502A, 502B, and 502C. The plurality of crankshafts 7A, 7B, 7C rotate together with the plurality of crankshaft gears 502A, 502B, 502C, and rotate a pair of planetary gears 3 (first planetary gear 301 and second planetary gear 302) around the rotation axis Ax1. Shake it.

In this embodiment, by sandwiching the flange portion 73 between the pair of planetary gears 3, even in the distribution type gear device 1D having a plurality of crankshafts 7A, 7B, 7C, the axes of the plurality of crankshafts 7A, 7B, 7C Directional movement can be restricted.

Here, each of the plurality of crankshaft gears 502A, 502B, and 502C also serves as a flange portion 73, and is arranged so as to be sandwiched between the pair of planetary gears 3. That is, as shown in FIG. 19, each crankshaft gear 502A, 502B, 502C is arranged between two eccentric parts 72 in the axial direction of each crankshaft 7A, 7B, 7C, and is also used as a flange part 73. Good too. This makes it possible to reduce the number of parts compared to the case where the crankshaft gears 502A, 502B, and 502C are provided separately from the flange portion 73.

The configuration of Embodiment 2 can be employed in appropriate combination with the various configurations (including modified examples) described in Reference Example 1, Embodiment 1, or Embodiment 2.

(summary)
As explained above, the internal meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the first aspect includes an internal gear (2), a pair of planetary gears (3), and a crankshaft. (7A, 7B, 7C), a pair of carriers (18, 19), and a regulating structure (9), and by swinging the pair of planetary gears (3), the pair of planetary gears (3) is rotated relative to the internal gear (2). The internal gear (2) is held rotatably in an annular gear body (22) and a plurality of inner circumferential grooves (223) formed on the inner circumferential surface (221) of the gear body (22). It has a plurality of outer pins (23) forming teeth (21). The pair of planetary gears (3) have external teeth (31) that partially mesh with the internal teeth (21). The crankshafts (7A, 7B, 7C) swing the pair of planetary gears (3) by rotating around the axis (Ax2). The pair of carriers (18, 19) are arranged on both sides in the axial direction along the axis (Ax2) of the pair of planetary gears (3), and rotatably support the crankshaft (7A, 7B, 7C). The regulating structure (9) regulates movement of the crankshaft (7A, 7B, 7C) relative to the pair of planetary gears (3) in the axial direction. The regulation structure (9) has a flange portion (73) located at at least one location in the axial direction of the crankshaft (7A, 7B, 7C) and arranged to be sandwiched between the pair of planetary gears (3).

According to this aspect, the axial movement of the crankshafts (7A, 7B, 7C) can be restricted using the flange portion (73) provided on the crankshafts (7A, 7B, 7C). As a result, the internally meshing planetary gears (1, 1A, 1B, 1C, 1D) do not use tapered roller bearings or covers attached to the pair of carriers (18, 19), and are relatively simple. Despite this configuration, the axial movement of the crankshafts (7A, 7B, 7C) can be restricted. Therefore, it is possible to reduce rattling, transmission loss, etc. due to axial movement of the crankshafts (7A, 7B, 7C).

In the internal meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the second aspect, the flange portion (73) is configured integrally with the crankshaft (7A, 7B, 7C), or It is coupled to the crankshaft (7A, 7B, 7C) so as to be in direct contact with the crankshaft (7A, 7B, 7C).

According to this aspect, since the flange portion (73) is sandwiched between the pair of planetary gears (3), the axial movement of the crankshafts (7A, 7B, 7C) can be reliably restricted.

In the internal meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the third aspect, in the first or second aspect, the pair of planetary gears (3) are connected to the pair of carriers (18, 19). axial movement is restricted.

According to this aspect, the crankshafts (7A, 7B, 7C) provided with the flange portions (73) can be indirectly positioned in the axial direction with respect to the pair of carriers (18, 19).

In the internally meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the fourth aspect, in the third aspect, the pair of planetary gears (3) are held by the pair of carriers (18, 19). By directly or indirectly contacting the outer ring (62) of the bearing member (6), axial movement relative to the pair of carriers (18, 19) is restricted.

According to this aspect, a gap can be secured between the pair of planetary gears (3) and the pair of carriers (18, 19) while regulating the movement of the pair of planetary gears (3) in the axial direction. is possible.

The internally meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the fifth aspect includes at least one of the pair of planetary gears (3) and the flange portion ( 73), plate-shaped parts (washers 81, 83) are further provided.

According to this aspect, slippage between the flange portion (73) and the planetary gear (3) can be dispersed by the plate-shaped parts (washers 81, 83).

In the internally meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the sixth aspect, in any one of the first to fifth aspects, the crankshaft (7A, 7B, 7C) is It has step portions (70) at at least two locations. A first lubrication path (S1) through which lubricant passes is formed between the step portion (70) and the pair of carriers (18, 19).

According to this aspect, the lubricant can be circulated through the lubricant path (S1) by securing the lubricant path (S1) between the step portion (70) and the pair of carriers (18, 19). , the lubrication state around the crankshafts (7A, 7B, 7C) can be improved.

In the internal meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the seventh aspect, in any one of the first to sixth aspects, at least one of the pair of planetary gears (3) and the flange portion ( 73), a second lubrication path (S3) through which lubricant passes is formed.

According to this aspect, the lubricant also circulates between at least one of the planetary gears (3) and the flange portion (73), so it is possible to further improve the lubrication state.

The internally meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the eighth aspect is the input gear (501) that rotates around the rotation axis (Ax1) in any one of the first to seventh aspects. ), and a plurality of crankshaft gears (502A, 502B, 502C) that are arranged around the input gear (501) so as to mesh with the input gear (501) and rotate in synchronization with each other when the input gear (501) rotates. and further provided. A plurality of crankshafts (7A, 7B, 7C) are provided in one-to-one correspondence with a plurality of crankshaft gears (502A, 502B, 502C). The plurality of crankshafts (7A, 7B, 7C) rotate together with the plurality of crankshaft gears (502A, 502B, 502C), and swing the pair of planetary gears (3) about the rotation axis (Ax1).

According to this aspect, in the distribution type internal meshing planetary gear device (1, 1A, 1B, 1C, 1D), although the configuration is relatively simple, the axial direction of the crankshaft (7A, 7B, 7C) It is possible to regulate the movement of people.

In the internal meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to the ninth aspect, in the eighth aspect, each of the plurality of crankshaft gears (502A, 502B, 502C) has a flange portion ( 73), and is arranged so as to be sandwiched between a pair of planetary gears (3).

According to this aspect, it is possible to reduce the number of parts compared to the case where the crankshaft gears (502A, 502B, 502C) are provided separately from the flange portion (73).

A robot joint device (200) according to a tenth aspect includes an internal meshing planetary gear device (1, 1A, 1B, 1C, 1D) according to any one of the first to ninth aspects, and a gear body (22). and a first member (201) that rotates relative to the first member (201) as the pair of planetary gears (3) rotate relative to the internal gear (2). 2 members (202).

According to this aspect, although the configuration is relatively simple, the axial movement of the crankshafts (7A, 7B, 7C) can be restricted.

The configurations according to the second to ninth aspects are not essential to the internal meshing planetary gear device (1, 1A, 1B, 1C, 1D) and can be omitted as appropriate.

1, 1A, 1B, 1C, 1D Internal meshing planetary gear device 2 Internal gear 3 Planetary gear 6 Bearing member 62 Outer ring 7A, 7B, 7C Crankshaft 9 Regulation structure 18 Input side carrier (carrier)
19 Output side carrier (carrier)
21 Internal tooth 22 Gear body 23 External pin 31 External tooth 70, 701, 702, 703, 704 Step portion 73 Flange portion 81, 83 Washer (plate-shaped part)
200 Joint device for robot 201 First member 202 Second member 221 Inner peripheral surface (of the gear body) 223 Inner peripheral groove 501 Input gear 502A, 502B, 502C Crankshaft gear Ax1 Rotating shaft Ax2 Axis center S1 (first) lubrication path S3 2nd lubrication path

Claims (10)

An internal gear having an annular gear body and a plurality of outer pins that are held in a rotatable state in a plurality of inner circumferential grooves formed on an inner circumferential surface of the gear body and constitute internal teeth;
a pair of planetary gears having external teeth that partially mesh with the internal teeth;
a crankshaft that swings the pair of planetary gears by rotating around its axis;
a pair of carriers that are arranged on both sides of the pair of planetary gears in the axial direction along the axis thereof and rotatably support the crankshaft;
a regulating structure that regulates movement of the crankshaft relative to the pair of planetary gears in the axial direction,
By rocking the pair of planetary gears, the pair of planetary gears are rotated relative to the internal gear,
The regulation structure includes a flange portion located at at least one location in the axial direction of the crankshaft and arranged to be sandwiched between the pair of planetary gears.
Internal meshing planetary gear system. The flange portion is configured integrally with the crankshaft or is coupled to the crankshaft so as to be in direct contact with the crankshaft.
The internally meshing planetary gear system according to claim 1. Movement of the pair of planetary gears in the axial direction with respect to the pair of carriers is restricted;
The internal meshing planetary gear device according to claim 1 or 2. The pair of planetary gears is regulated from moving in the axial direction relative to the pair of carriers by directly or indirectly contacting an outer ring of a bearing member held by the pair of carriers. ,
The internally meshing planetary gear system according to claim 3. further comprising a plate-shaped component disposed between at least one of the pair of planetary gears and the flange portion;
The internal meshing planetary gear device according to claim 1 or 2. The crankshaft has step portions at at least two locations in the axial direction,
A first lubrication path through which a lubricant passes is formed between the step portion and the pair of carriers, respectively.
The internal meshing planetary gear device according to claim 1 or 2. A second lubrication path through which a lubricant passes is formed between at least one of the pair of planetary gears and the flange portion.
The internal meshing planetary gear device according to claim 1 or 2. An input gear that rotates around a rotation axis,
further comprising a plurality of crankshaft gears arranged around the input gear so as to mesh with the input gear and rotate in synchronization with each other when the input gear rotates,
A plurality of the crankshafts are provided in one-to-one correspondence with the plurality of crankshaft gears,
The plurality of crankshafts rotate together with the plurality of crankshaft gears, and swing the pair of planetary gears about the rotation axis.
The internal meshing planetary gear device according to claim 1 or 2. Each of the plurality of crankshaft gears also serves as the flange portion, and is arranged so as to be sandwiched between the pair of planetary gears.
The internally meshing planetary gear system according to claim 8. The internal meshing planetary gear device according to claim 1 or 2,
a first member fixed to the gear body;
a second member that rotates relative to the first member as the pair of planetary gears rotates relative to the internal gear;
Robot joint device.