JP7273782B2 - Internal meshing planetary gear system, wheel system and vehicle - Google Patents

Description

FIELD OF THE DISCLOSURE The present disclosure relates generally to internally meshing planetary gear systems and wheel systems and vehicles, and more particularly to internally meshing planetary gear systems in which planetary gears with external teeth are arranged inside internal gears with internal teeth. , wheel devices and vehicles.

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

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

JP-A-2003-74646

In the configuration of the above-mentioned related art, a cross roller bearing is used as a bearing member, so the cross roller bearing having a relatively complicated structure hinders the simplification of the structure of the internal meshing planetary gear device as a whole. There is

An object of the present disclosure is to provide an internal meshing planetary gear device, a wheel device, and a vehicle that facilitate simplification of the structure.

An internally meshing planetary gear device according to an aspect of the present disclosure includes an internal gear, a planetary gear, a plurality of inner pins, and a first bearing member. The internal gear has an annular gear body and a plurality of external pins that are held on the inner peripheral surface of the gear body in a rotatable state and form internal teeth. The planetary gear has external teeth that partially mesh with the internal teeth. The plurality of inner pins are inserted into the plurality of loose fitting holes formed in the planetary gear and rotate relatively to the gear body while revolving in the loose fitting holes. The first bearing member rotatably supports the plurality of inner pins with respect to the gear body. The first bearing member has a first inner ring, a first outer ring, and a plurality of bearing pins. The plurality of bearing pins are held between the first inner ring and the first outer ring in a rotatable state. The plurality of outer pins and the plurality of bearing pins have different diameters and different holding structures.

A wheel device according to an aspect of the present disclosure is a wheel body that rolls on a running surface by the internal meshing planetary gear device and rotational output when the plurality of inner pins rotate relative to the gear body. And prepare.

A vehicle according to an aspect of the present disclosure includes the wheel device and a vehicle body that holds the wheel device.

According to the present disclosure, it is possible to provide an internal meshing planetary gear device, a wheel device, and a vehicle that facilitate structural simplification.

FIG. 1A is a perspective view showing a schematic configuration of an internally meshing planetary gear device according to a basic configuration, viewed from the output side of a rotating shaft. FIG. 1B is a perspective view showing the schematic configuration of the internal meshing planetary gear device of the same, seen from the input side of the rotating shaft. FIG. 2 is a schematic exploded perspective view of the internal meshing planetary gear device as seen from the output side of the rotary shaft. FIG. 3 is a schematic cross-sectional view of the internal meshing planetary gear device of the same. 4 is a cross-sectional view taken along the line A1-A1 of FIG. 3 and a partially enlarged view thereof, showing the internal meshing planetary gear device of the same. FIG. 5 is a perspective view mainly showing a configuration around an internal gear and a planetary gear of the internal meshing planetary gear device of the same. FIG. 6 is an exploded perspective view mainly showing the configuration around the internal gear and the planetary gear of the internal meshing planetary gear device of the same. 7 is a cross-sectional view taken along line B1-B1 of FIG. 3 and a partially enlarged view thereof, showing the internal meshing planetary gear device of the same. FIG. 8 is a perspective view mainly showing the configuration around the first bearing member of the internal meshing planetary gear device of the same. FIG. 9 is an exploded perspective view mainly showing the configuration around the first bearing member of the internal meshing planetary gear device of the same. FIG. 10 is an enlarged view of area Z1 in FIG. 3 showing the internal meshing planetary gear system of the same. FIG. 11 is a schematic perspective view of a wheel device and a vehicle using the internal meshing planetary gear device of the above. FIG. 12 is an enlarged view corresponding to FIG. 10, showing an internal meshing planetary gear device according to a modification of the basic configuration. 13 is a schematic cross-sectional view of the internally meshing planetary gear device according to Embodiment 1. FIG. 14 is a cross-sectional view taken along line B1-B1 of FIG. 13 and a partially enlarged view thereof, showing the internal meshing planetary gear device of the same. 15 is an enlarged view corresponding to FIG. 10 showing an internal meshing planetary gear device according to a modification of the first embodiment. FIG. 16 is a schematic cross-sectional view of an internally meshing planetary gear device according to Embodiment 2. FIG. 17 is a cross-sectional view taken along line B1-B1 of FIG. 16 and a partially enlarged view thereof, showing the internal meshing planetary gear device of the same.

(basic configuration)
(1) Overview An overview of the internally meshing planetary gear device 1 according to the present configuration will be described below with reference to FIGS. 1A to 4. FIG. The drawings referred to in this disclosure are all schematic diagrams, and the ratio of the size and thickness of each component in the drawing does not necessarily reflect the actual dimensional ratio. For example, the tooth profile, size, number of teeth, etc. of the internal teeth 21 and the external teeth 31 in FIGS. not on purpose.

An internal meshing planetary gear device 1 (hereinafter also simply referred to as "gear device 1") according to this configuration includes an internal gear 2 (see FIG. 4), a planetary gear 3, and a plurality of inner pins 4. It is a gear device. In this gear device 1 , a planetary gear 3 is arranged inside an annular internal gear 2 , and an eccentric body bearing 5 is arranged inside the planetary gear 3 . The eccentric bearing 5 has an eccentric inner ring 51 and an eccentric outer ring 52, and the eccentric inner ring 51 rotates around a rotation axis Ax1 (see FIG. 3) deviated from the center C1 (see FIG. 3) of the eccentric inner ring 51. The planetary gear 3 is oscillated by (eccentric motion). The eccentric inner ring 51 rotates (eccentrically moves) around the rotation axis Ax1 as shown in FIG.

The internal gear 2 has internal teeth 21 . Specifically, in this configuration, the internal gear 2 has an annular gear body 22 and a plurality of external pins 23 . A plurality of outer pins 23 are held on the inner peripheral surface 221 of the gear body 22 in a rotatable state, and constitute the inner teeth 21 . The planetary gear 3 has external teeth 31 that partially mesh with the internal teeth 21 . That is, the planetary gear 3 is inscribed with the internal gear 2 inside the internal gear 2 , and a portion of the external teeth 31 meshes with a portion of the internal teeth 21 . In this state, when the eccentric shaft 54 rotates, the planetary gear 3 swings, and the meshing position between the internal tooth 21 and the external tooth 31 moves in the circumferential direction of the internal gear 2, and the planetary gear 3 and the internal gear move. 2 generates relative rotation between the two gears (the internal gear 2 and the planetary gear 3). Here, if the internal gear 2 is fixed, the planetary gear 3 will rotate (rotate) with the relative rotation of both gears. As a result, from the planetary gear 3, a rotational output reduced at a relatively high reduction ratio is obtained in accordance with the difference in the number of teeth between the two gears.

The gear device 1 of this type allows the relative rotation between the planetary gear 3 and the internal gear 2, that is, the rotation corresponding to the rotation component of the planetary gear 3 when the internal gear 2 is fixed, to be, for example, It is used to extract as the relative rotation of the rotating member with respect to the stationary member. In short, the gear device 1 rotates the rotary member with its output while the fixed member is fixed. As a result, the gear device 1 functions as a gear device with a relatively high reduction ratio, with the eccentric shaft 54 on the input side and the rotating member on the output side. Therefore, in the gear device 1 according to this configuration, in order to transmit the relative rotation between the planetary gear 3 and the internal gear 2 to the fixed member and the rotary member, the gear body 22 is attached to one of the fixed member and the rotary member. is fixed, and the planetary gear 3 is connected with a plurality of inner pins 4 to the other of the fixed member and the rotating member.

The plurality of inner pins 4 are inserted into the plurality of loose fitting holes 32 formed in the planetary gear 3 and rotate relatively to the internal gear 2 while revolving in the loose fitting holes 32 . . That is, the loose fitting hole 32 has a larger diameter than the inner pin 4 , and the inner pin 4 can move to revolve inside the loose fitting hole 32 while being inserted into the loose fitting hole 32 . The oscillation component of the planetary gear 3 , that is, the revolution component of the planetary gear 3 is absorbed by the loose fitting between the loose fitting hole 32 of the planetary gear 3 and the inner pin 4 . In other words, the oscillating component of the planetary gear 3 is absorbed by the plurality of inner pins 4 revolving inside the plurality of loose fitting holes 32 . Therefore, the rotation (rotational component) of the planetary gear 3 excluding the oscillation component (revolution component) of the planetary gear 3 is transmitted to the fixed member or the rotating member by the plurality of inner pins 4 .

In this manner, relative rotation between the planetary gear 3 and the internal gear 2 is transmitted to the stationary member and the rotating member as relative rotation between the gear body 22 and the plurality of inner pins 4 . Therefore, in the gear device 1, the reduced rotational output can be obtained from either the planetary gear 3 or the internal gear 2. That is, for example, when the gear body 22 is fixed to a fixed member, the planetary gear 3 is connected to the rotating member by a plurality of inner pins 4, so that the space between the planetary gear 3 and the internal gear 2 is Relative rotation is taken from planetary gear 3 . On the other hand, when the gear main body 22 is fixed to the rotating member, the planetary gear 3 is connected to the fixed member by the plurality of inner pins 4, so that the planetary gear 3 and the internal gear 2 are mutually A positive rotation is extracted from the internal gear 2 .

The gear device 1 also includes a (first) bearing member 6 . The bearing member 6 has a (first) inner ring 61 and a (first) outer ring 62 . The inner ring 61 is arranged inside the outer ring 62 and supported to be relatively rotatable with respect to the outer ring 62 . The bearing member 6 is a component for rotatably supporting the rotating member with respect to the fixed member. In other words, the (first) bearing member 6 is a component that rotatably supports the plurality of inner pins 4 with respect to the gear body 22 . The gear device 1 is supported by such a bearing member 6 so that the rotating member can rotate with respect to the fixed member. rotation can be output as the rotation of the rotating member with respect to the fixed member.

By the way, in this type of gear device 1, it is known as a related technology to use a cross roller bearing as a bearing member. In the crossed roller bearing, the axis of the cylindrical rolling element (roller) has an inclination of 45 degrees with respect to a plane orthogonal to the rotation axis Ax1, is orthogonal to the outer circumference of the inner ring, and is perpendicular to the circle of the inner ring. Axes of a pair of rolling elements adjacent to each other in the circumferential direction are orthogonal to each other. That is, in the gear device 1, depending on the application, loads in various directions such as loads in the radial direction, loads in the thrust direction (direction along the rotation axis Ax1), and bending forces (bending moment loads) with respect to the rotation axis Ax1 are applied. A load can act. In the related art, cross roller bearings are used as bearing members to withstand loads in these various directions. However, in the related art, a cross roller bearing is used as a bearing member, so the cross roller bearing having a relatively complicated structure may hinder the simplification of the structure of the gear device 1 as a whole. The gear device 1 according to this configuration can provide an internal meshing planetary gear device 1 that facilitates structural simplification by the following configuration.

That is, as shown in FIGS. 1 to 3, the gear device 1 according to this configuration includes an internal gear 2, a planetary gear 3, a plurality of inner pins 4, a first bearing member 6 and a second bearing member 7. And prepare. The internal gear 2 has an annular gear main body 22 and a plurality of outer pins 23 that are held on an inner peripheral surface 221 of the gear main body 22 in a rotatable state and constitute the internal teeth 21 . The planetary gear 3 has external teeth 31 that partially mesh with the internal teeth 21 . The plurality of inner pins 4 are inserted into the plurality of loose fitting holes 32 formed in the planetary gear 3 and rotate relatively to the gear body 22 while revolving inside the loose fitting holes 32 . The first bearing member 6 and the second bearing member 7 rotatably support the plurality of inner pins 4 with respect to the gear body 22 at two locations along the rotation axis Ax1. Here, the first bearing member 6 has a first inner ring 61 , a first outer ring 62 and a plurality of bearing pins 63 . Furthermore, the plurality of inner pins 4 are positioned inside the second bearing member 7 when viewed from one side in the direction of the rotation axis Ax1.

According to this aspect, the first bearing member 6 and the second bearing member 7 rotatably support the plurality of inner pins 4 with respect to the gear body 22 at two locations in the direction of the rotation axis Ax1. A plurality of inner pins 4 are supported at two points. Therefore, compared to the one-point support in which a plurality of inner pins 4 are supported with respect to the gear body 22 at one point in the direction of the rotation axis Ax1, it is easier to withstand a load such as a bending force (bending moment load) with respect to the rotation axis Ax1. . Moreover, the first bearing member 6 has a first inner ring 61 , a first outer ring 62 and a plurality of bearing pins 63 . That is, the first bearing member 6 is a needle bearing having the bearing pin 63 as a "roller", and can withstand a relatively large load in the radial direction. Furthermore, even though the two-point support is provided, since the second bearing member 7 is positioned outside the plurality of inner pins 4 when viewed from one direction of the rotation axis Ax1, the limited space inside the plurality of inner pins 4 is relatively small. can have a relatively simple structure. Therefore, the gear device 1 according to the present configuration has an advantage that the structure can be easily simplified as compared with the related art that uses a cross roller bearing as a bearing member.

Furthermore, since the cross roller bearing is one of the expensive bearing members, according to the configuration of the gear device 1 according to the present configuration, such a cross roller bearing can be omitted, so that cost reduction can be easily achieved. There are also advantages.

(2) Definition “Annular” in the present disclosure means a ring-like shape that forms a space (area) surrounded inside at least in plan view, and a perfect circle and a certain circle in plan view The shape is not limited to an annular shape, and may be, for example, an elliptical shape, a polygonal shape, or the like. Furthermore, for example, even a shape having a bottom, such as a cup shape, is included in the "annular shape" as long as the peripheral wall is annular.

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

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

Further, in the present disclosure, one side of the rotation axis Ax1 (the right side in FIG. 3) may be referred to as the "input side" and the other side of the rotation axis Ax1 (the left side in FIG. 3) may be referred to as the "output side." In the example of FIG. 3, rotation is given to the rotating body (eccentric inner ring 51) from the "input side" of the rotation axis Ax1, and the rotation between the planetary gear 3 and the internal gear 2 is given from the "output side" of the rotation axis Ax1. Relative rotation is retrieved. However, the terms "input side" and "output side" are merely labels attached for explanation, and are not meant to limit the positional relationship between the input and the output as viewed from the gear device 1 .

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

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

(3) Structure Hereinafter, the detailed structure of the internal meshing planetary gear device 1 according to the present structure will be described with reference to FIGS. 1A to 10. FIG.

FIG. 1A shows a schematic configuration of the gear device 1, and is a perspective view of the gear device 1 as seen from the output side (left side in FIG. 3) of the rotating shaft Ax1. FIG. 1B shows a schematic configuration of the gear device 1, and is a perspective view of the gear device 1 viewed from the input side (right side in FIG. 3) of the rotation axis Ax1. FIG. 2 is a schematic exploded perspective view of the gear device 1 viewed from the output side of the rotating shaft Ax1. FIG. 3 is a schematic cross-sectional view of the gear device 1. FIG. FIG. 4 is a cross-sectional view taken along line A1-A1 of FIG. 3 and a partially enlarged view thereof. FIG. 5 is a perspective view mainly showing the configuration around the internal gear 2 and the planetary gears 3 of the gear device 1, and FIG. 6 is an exploded perspective view thereof. FIG. 7 is a cross-sectional view along line B1-B1 of FIG. 3 and a partially enlarged view thereof. FIG. 8 is a perspective view mainly showing the configuration around the first bearing member 6 of the gear device 1, and FIG. 9 is an exploded perspective view thereof. FIG. 10 is an enlarged view of area Z1 in FIG. However, in FIGS. 4 and 7, parts other than the eccentric shaft 54 are omitted from hatching even in cross sections.

(3.1) Overall Configuration As shown in FIGS. 1A to 3, the gear device 1 according to this configuration includes an internal gear 2, a planetary gear 3, a plurality of inner pins 4, an eccentric bearing 5, A first bearing member 6 , a second bearing member 7 , an eccentric shaft 54 and a support 8 are provided. Moreover, in this configuration, the gear device 1 further includes a holding member 55 , a balance weight 56 , a first bearing 91 , a second bearing 92 , a spacer 93 and a case 10 . In this configuration, the materials of the internal gear 2, the planetary gear 3, the plurality of inner pins 4, the eccentric bearing 5, the first bearing member 6, the second bearing member 7, etc., which are the constituent elements of the gear device 1, are stainless steel, Metals such as cast iron, carbon steel for machine structural use, chromium molybdenum steel, phosphor bronze or aluminum bronze. Furthermore, the materials of the eccentric shaft 54, the support 8, the holding member 55, the balance weight 56, the case 10, etc. are also metals similar to those described above. The metal referred to here includes a metal subjected to surface treatment such as nitriding.

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

Further, in this configuration, as an example, the gear device 1 is used in a state in which the holding member 55 (see FIG. 2) that holds the plurality of inner pins 4 is fixed to a fixing member (hub member 14 or the like, which will be described later). That is, since the planetary gear 3 is connected to a fixed member by a plurality of inner pins 4 and the gear body 22 is fixed to a rotating member (such as a body portion 11 to be described later), there is no space between the planetary gear 3 and the internal gear 2. is taken out of the internal gear 2 . In other words, in this configuration, when the plurality of inner pins 4 rotate relative to the gear body 22, the rotational force of the gear body 22 is taken out as an output.

Furthermore, although details will be described later, in this configuration, as an example, the gear device 1 is used in a wheel device W1 (see FIG. 11). In this case, the rotating member (body part 11, etc.) functions as the wheel body 102 (see FIG. 11), so that the wheel body 102 can be rotated with the relative rotation between the internal gear 2 and the planetary gears 3. can. As described above, in this configuration, by using the gear device 1 in the wheel device W1, the rotation output when the plurality of inner pins 4 rotate relative to the gear body 22 causes the wheel body 102 to move on the running surface. The wheel body 102 can be driven so as to roll. In short, when the gear device 1 is used as the wheel device W1, a rotational force as an input is applied to the eccentric shaft 54, so that a rotational force as an output is taken out from the rotating member (such as the trunk portion 11) as the wheel body 102. be In other words, the gear device 1 operates using the rotation of the eccentric shaft 54 as input rotation and the rotation of the rotating member (body portion 11 and the like) to which the gear body 22 is fixed as output rotation. As a result, in the gear device 1 , the output rotation reduced by a relatively high reduction ratio with respect to the input rotation is obtained as the rotation of the wheel body 102 .

Furthermore, in the gear device 1 according to this configuration, as shown in FIG. 3, the input-side rotation axis Ax1 and the output-side rotation axis Ax1 are on the same straight line. In other words, the input-side rotation axis Ax1 and the output-side rotation axis Ax1 are coaxial. Here, the input-side rotation axis Ax1 is the rotation center of the eccentric shaft 54 to which the input rotation is applied, and the output-side rotation axis Ax1 is the rotation center of the gear body 22 that produces the output rotation. In other words, in the gear device 1, the output rotation is coaxially reduced with respect to the input rotation with a relatively high reduction ratio.

As shown in FIGS. 1A and 1B, the case 10 is cylindrical and constitutes the outer shell of the gear device 1. As shown in FIGS. In this configuration, the case 10 functions as the wheel body 102, so the central axis of the cylindrical case 10 is configured to coincide with the rotation axis Ax1. That is, at least the outer peripheral surface of the case 10 forms a perfect circle centered on the rotation axis Ax1 in a plan view (viewed from one side in the direction of the rotation axis Ax1).

Case 10 has body 11 , cap 12 , ring cap 13 , and hub member 14 . The trunk portion 11 is a cylindrical component that is open at both end faces in the direction of the rotation axis Ax1. The cap 12 is a disk-shaped component that is attached to the end face of the body 11 on the output side (left side in FIG. 3) of the rotation axis Ax1 and closes the opening of the body 11 on the output side of the rotation axis Ax1. The ring cap 13 is an annular component attached to the end face of the trunk portion 11 on the input side (the right side in FIG. 3) of the rotation axis Ax1. The hub member 14 is an annular component arranged inside the ring cap 13 . A part of the opening surface of the trunk portion 11 on the input side of the rotation axis Ax1 is closed by the hub member 14 . Here, the trunk portion 11, the cap 12, the ring cap 13, and the hub member 14 are all formed in a perfect circle shape centering on the rotation axis Ax1 in plan view.

A plurality (eight as an example) of screw holes 111 (see FIG. 5) are formed in the end surface of the body portion 11 on the output side of the rotation axis Ax1. A plurality of screw holes 111 are used to secure the cap 12 to the barrel 11 . Specifically, a plurality of fixing screws 151 (eg, eight screws) are passed through the cap 12 and screwed into the screw holes 111 , thereby fixing the cap 12 to the body 11 . A plurality of (eight as an example) screw holes 112 (see FIG. 8) are formed around the end surface of the body portion 11 on the input side of the rotation axis Ax1. A plurality of screw holes 112 are used to secure the ring cap 13 to the barrel 11 . Specifically, a plurality of fixing screws 152 (eg, eight screws) are threaded through the ring cap 13 and tightened into the screw holes 112 , thereby fixing the ring cap 13 to the trunk portion 11 .

In the space surrounded by the body portion 11, the cap 12, the ring cap 13 and the hub member 14, that is, the internal space of the case 10, the internal gear 2, the planetary gear 3, the plurality of inner pins 4, the eccentric body bearing 5 , the first bearing member 6, the second bearing member 7, the support 8 and the like are accommodated. The hub member 14 is attached to the holding member 55 holding the plurality of inner pins 4 from the input side of the rotation axis Ax1. A plurality of (eg, eight) screw holes 554 (see FIG. 9) are formed in the end surface of the holding member 55 on the input side of the rotation axis Ax1. A plurality of threaded holes 554 are used to secure the hub member 14 to the retaining member 55 . Specifically, the hub member 14 is fixed to the holding member 55 by threading a plurality of fixing screws 153 (eg, eight screws) into the screw holes 554 through the hub member 14 .

Here, a plurality of (for example, four) fixing holes 141 (see FIG. 1B) are formed in the end surface of the hub member 14 on the input side of the rotating shaft Ax1. A plurality of fixing holes 141 are used to fix the hub member 14 . In this configuration, since the gear device 1 is used for the wheel device W1, the hub member 14 is fixed to the vehicle body 100 (see FIG. 11) to which the wheel device W1 is attached. Specifically, hub member 14 is fixed to vehicle body 100 by screwing a plurality of fixing screws (four screws as an example) through part of vehicle body 100 and into fixing hole 141 . In this way, the hub member 14 is fixed to the vehicle body 100 in the case 10 constituting the wheel body 102 and constitutes a "fixed member" that does not rotate even when the gear device 1 is driven. On the other hand, the body portion 11, the cap 12 and the ring cap 13 constitute a "rotating member" that rotates relative to the hub member 14 when the gear device 1 is driven. That is, when the plurality of inner pins 4 rotate relative to the gear main body 22, the rotation of the rotating members (body portion 11, cap 12 and ring cap 13) with respect to the fixed member (hub member 14) causes the gear device 1 to rotate. is retrieved as the output of When the case 10 is used as the wheel body 102, these rotating members rotate and roll on the running surface.

Therefore, the ring cap 13, which is a rotating member, and the hub member 14, which is a fixed member, are configured to be relatively rotatable about the rotation axis Ax1. Specifically, the outer diameter of the hub member 14 is smaller than the inner diameter of the ring cap 13, and when the hub member 14 is arranged inside the ring cap 13, there is a gap between the hub member 14 and the ring cap 13. occurs.

In addition, the hub member 14 has a through hole 142 that penetrates the hub member 14 in the direction of the rotation axis Ax1 in the central portion in plan view. The through hole 142 is a hole through which the eccentric shaft 54 is passed. The hub member 14 and the eccentric shaft 54 are configured to be relatively rotatable around the rotation axis Ax1. Specifically, the inner diameter of the hub member 14 (the hole diameter of the through hole 142) is larger than the outer diameter of (the shaft center portion 541 of) the eccentric shaft 54, and the hub member 14 is inserted into the through hole 142. A gap is created between the member 14 and the eccentric shaft 54 .

Furthermore, in this configuration, the outer peripheral surface of the body portion 11, which is a rotating member, is the contact surface with the running surface of the wheel body 102, that is, the ground contact surface. Therefore, tires 103 made of rubber, for example, are attached to the outer peripheral surface of the trunk portion 11 . In FIGS. 1A and 1B, the tire 103 is indicated by an imaginary line (chain double-dashed line).

By the way, in this configuration, the body portion 11, which is a rotating member, includes the gear body 22 of the internal gear 2, the first outer ring 62 of the first bearing member 6, the second outer ring 72 of the second bearing member 7, is fixed. Here, as an example, the gear main body 22 and the first outer ring 62 are integrated with the body portion 11 . The trunk portion 11 has an outer ring fixing frame 74 (see FIG. 10) for fixing the second outer ring 72 . In particular, in this configuration, the gear body 22, the first outer ring 62, and the outer ring fixing frame 74 are integrally formed of a single metal member. It is treated as one seamless part (body 11). The gear main body 22, the first outer ring 62, and the outer ring fixing frame 74 are arranged in the order of the gear main body 22, the first outer ring 62, and the outer ring fixing frame 74 from the output side of the rotating shaft Ax1. Therefore, the inner peripheral surface of the trunk portion 11 includes the inner peripheral surface 221 of the gear body 22 and the inner peripheral surface 621 of the first outer ring 62, as shown in FIG.

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

Here, the internal gear 2 has an annular (annular) gear main body 22 and a plurality of outer pins 23 as described above. A plurality of outer pins 23 are held on the inner peripheral surface 221 of the gear body 22 in a rotatable state, and constitute the inner teeth 21 . In other words, the plurality of outer pins 23 function as a plurality of teeth forming the inner teeth 21 respectively. Specifically, as shown in FIG. 6, the inner peripheral surface 221 of the gear body 22 is formed with a plurality of grooves over the entire circumference. These plurality of grooves are a plurality of gear side grooves 222 (see FIG. 4) as holding structures for the plurality of outer pins 23, respectively. In other words, the structure for holding the plurality of outer pins 23 includes a plurality of gear side grooves 222 formed on the inner peripheral surface 221 of the gear body 22 . All of the plurality of gear side grooves 222 have the same shape and are provided at equal pitches. The plurality of gear side grooves 222 are all parallel to the rotation axis Ax1 and formed over the entire width of the gear body 22 .

However, in this configuration, since the gear body 22 is a part of the body 11 as described above, the plurality of gear side grooves 222 are provided only in the parts of the body 11 corresponding to the gear body 22 (see FIG. 10). formed. The plurality of outer pins 23 are combined with the gear main body 22 (body portion 11 ) so as to fit in the plurality of gear side grooves 222 . Each of the plurality of outer pins 23 is held in the gear side groove 222 in a rotatable state, and the gear side groove 222 restricts the movement of the gear body 22 in the circumferential direction.

The planetary gear 3 is an annular component having external teeth 31, as shown in FIGS. In this configuration, the planetary gear 3 has an annular shape in which at least the outer peripheral surface is a perfect circle in plan view. External teeth 31 are formed along the circumferential direction of the planetary gear 3 on the outer peripheral surface of the annular planetary gear 3 . The plurality of teeth forming the external teeth 31 are all of the same shape, and are provided at equal pitches over the entire peripheral surface of the planetary gear 3 in the circumferential direction. That is, the pitch circle of the external teeth 31 is a perfect circle in plan view. The center C1 of the pitch circle of the external teeth 31 is located at a position displaced from the rotation axis Ax1 by a distance ΔL (see FIG. 4). Also, the planetary gear 3 has a predetermined thickness in the direction of the rotation axis Ax1. Each of the external teeth 31 is formed over the entire length of the planetary gear 3 in the thickness direction. All of the tooth traces of the external teeth 31 are parallel to the rotation axis Ax1. In the planetary gear 3, unlike the internal gear 2, the external teeth 31 are integrally formed with the main body of the planetary gear 3 by one metal member.

Here, the planetary gear 3 is combined with the eccentric body bearing 5 and the eccentric shaft 54 . That is, as shown in FIGS. 5 and 6, the planetary gear 3 is formed with a circular opening 33 . The opening 33 is a hole penetrating through the planetary gear 3 along the thickness direction. In plan view, the center of the opening 33 and the center of the planetary gear 3 are aligned, and the inner peripheral surface of the opening 33 (the inner peripheral surface of the planetary gear 3) and the pitch circle of the external teeth 31 are concentric. . The eccentric bearing 5 is accommodated in the opening 33 of the planetary gear 3 . Further, the eccentric shaft 54 is inserted into (the eccentric inner ring 51 of) the eccentric bearing 5 , so that the eccentric bearing 5 and the eccentric shaft 54 are combined with the planetary gear 3 . When the eccentric shaft 54 rotates in a state where the planetary gear 3 is combined with the eccentric body bearing 5 and the eccentric shaft 54, the planetary gear 3 oscillates around the rotation axis Ax1.

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

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

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

Moreover, in this configuration, as an example, the thickness of the planetary gear 3 is smaller than the thickness of the gear main body 22 in the internal gear 2 . Strictly speaking, the thickness of the planetary gear 3 is smaller than the dimension in the direction parallel to the rotation axis Ax1 of the portion of the body 11 that functions as the gear body 22 (see FIG. 10). Furthermore, the dimension of the external teeth 31 in the tooth trace direction (the direction parallel to the rotation axis Ax1) is smaller than the dimension of the internal teeth 21 in the tooth trace direction (the direction parallel to the rotation axis Ax1). In other words, the external teeth 31 fit within the range of the tooth traces of the internal teeth 21 in the direction parallel to the rotation axis Ax1.

In this configuration, as described above, the relative rotation between the planetary gear 3 and the internal gear 2 is the relative rotation between the gear body 22 and the plurality of inner pins 4, and the fixed member and the rotating member. transmitted. As shown in FIGS. 5 and 6, the planetary gear 3 is formed with a plurality of loose fitting holes 32 for inserting a plurality of inner pins 4 therein. The loose fitting holes 32 are provided in the same number as the inner pins 4, and in this configuration, eight loose fitting holes 32 and eight inner pins 4 are provided as an example. Each of the plurality of loose fitting holes 32 is a hole that is circularly open and penetrates through the planetary gear 3 along the thickness direction. A plurality of (here, eight) loose fitting holes 32 are arranged at equal intervals in the circumferential direction on a virtual circle concentric with the opening 33 .

A plurality of inner pins 4 are parts that connect the planetary gear 3 and a fixed member or a rotating member. Particularly in this configuration, the planetary gear 3 is connected to a fixed member (hub member 14, etc.) by a plurality of inner pins 4, and the gear body 22 is fixed to a rotating member (body portion 11, etc.). Therefore, the planetary gear 3 is directly or indirectly connected to the fixed member (hub member 14 or the like) by the plurality of inner pins 4 . Each of the plurality of inner pins 4 is formed in a cylindrical shape. The diameter and length of the plurality of inner pins 4 are common to the plurality of inner pins 4 . The diameter of the inner pin 4 is one size smaller than the diameter of the loose fitting hole 32 . As a result, the inner pin 4 is inserted into the loose fitting hole 32 while securing a spatial allowance (clearance) between itself and the inner peripheral surface of the loose fitting hole 32 (see FIGS. 4 and 5).

The holding member 55 is a component that holds the plurality of inner pins 4 . In this configuration, as shown in FIGS. 8 and 9, the holding member 55 is formed in a perfect circle shape centering on the rotation axis Ax1 in a plan view and having approximately the same size as the hub member 14. . The holding member 55 has a plurality of holding holes 551 into which the plurality of inner pins 4 are respectively inserted. The holding holes 551 are provided in the same number as the inner pins 4, and in this configuration, eight holding holes 551 are provided as an example. Each of the plurality of holding holes 551 is a hole that opens in a circular shape and penetrates through the holding member 55 along the thickness direction. A plurality of (here, eight) holding holes 551 are arranged at regular intervals in the circumferential direction on a virtual circle concentric with the outer circumference of the holding member 55 . The diameter of the holding hole 551 is equal to or larger than the diameter of the inner pin 4 and smaller than the diameter of the loose fitting hole 32 .

In this configuration, the diameter of the holding hole 551 is substantially the same as the diameter of the inner pin 4 and slightly larger than the diameter of the inner pin 4 . Therefore, the movement of the inner pin 4 within the holding hole 551 is restricted, that is, the movement of the inner pin 4 relative to the center of the holding hole 551 is prohibited. Therefore, the inner pin 4 is held in the planetary gear 3 in a state in which it can revolve inside the loose fit hole 32 , and is held in a state in which it cannot revolve in the holding hole 551 with respect to the holding member 55 . As a result, the oscillating component of the planetary gear 3, that is, the revolving component of the planetary gear 3, is absorbed by the loose fit between the loose fitting hole 32 and the inner pin 4, and the holding member 55 is provided with a plurality of inner pins 4 to support the planetary gear 3. The rotation (rotation component) of the planetary gear 3 excluding the swing component (revolution component) of the gear 3 is transmitted.

Furthermore, in this configuration, since the diameter of the inner pin 4 is slightly larger than that of the holding hole 551, the inner pin 4 is prohibited from revolving within the holding hole 551 when inserted into the holding hole 551. , rotation within the holding hole 551 is possible. That is, even when the inner pin 4 is inserted into the holding hole 551 , it is not press-fitted into the holding hole 551 , so it can rotate within the holding hole 551 . As described above, in the gear device 1 according to this configuration, each of the plurality of inner pins 4 is held by the holding member 55 in a rotatable state. , the inner pin 4 itself can rotate.

In short, in this configuration, the inner pin 4 is held by the planetary gear 3 in such a state that it can both revolve and rotate within the loose fitting hole 32 , and is held by the holding member 55 within the holding hole 551 . It is held in a state where only rotation at is possible. That is, the plurality of inner pins 4 can revolve within the plurality of loose fitting holes 32 in a state in which their rotation is not restrained (a state in which rotation is possible). Therefore, when the rotation (rotational component) of the planetary gear 3 is transmitted to the holding member 55 by the plurality of inner pins 4 , the inner pins 4 revolve and rotate in the loose fitting holes 32 and rotate inside the holding holes 551 . can rotate at Therefore, when the inner pin 4 revolves in the loosely fitting hole 32 , the inner pin 4 is in a rotatable state, so it rolls on the inner peripheral surface of the loosely fitting hole 32 . In other words, since the inner pin 4 revolves within the loose fitting hole 32 so as to roll on the inner peripheral surface of the loose fitting hole 32 , the frictional resistance between the inner peripheral surface of the loose fitting hole 32 and the inner pin 4 is reduced. less likely to cause losses due to

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

The holding member 55 is fixed to the hub member 14, which is a fixed member. As a result, the planetary gear 3 is connected to the fixed member (hub member 14 ) via the holding member 55 by the plurality of inner pins 4 . Since the holding member 55 is fixed to the hub member 14 in this way, the holding member 55 may also be included in the "fixed member". As a result, the plurality of inner pins 4 are directly or indirectly held by the fixing member, so that their relative positions with respect to the rotation axis Ax1 are fixed. Furthermore, the opening surface of the holding hole 551 on the input side of the rotating shaft Ax1 is closed by the hub member 14, for example. As a result, the movement of the inner pin 4 toward the input side of the rotating shaft Ax1 is restricted by the hub member 14 .

In addition, the holding member 55 has a bearing hole 552 penetrating the holding member 55 in the direction of the rotation axis Ax1 at the central portion in plan view. The bearing hole 552 is a hole for passing the eccentric shaft 54 and communicates with the through hole 142 of the hub member 14 . The holding member 55 and the eccentric shaft 54 are configured to be relatively rotatable around the rotation axis Ax1. Specifically, the inner diameter of the holding member 55 (the diameter of the bearing hole 552 ) is larger than the outer diameter of (the shaft center portion 541 of) the eccentric shaft 54 . A gap is created between the member 55 and the eccentric shaft 54 .

Here, the first inner ring 61 of the first bearing member 6 and the second inner ring 71 of the second bearing member 7 are fixed to the holding member 55 . In this configuration, as an example, the first inner ring 61 is integrated with the holding member 55 . Specifically, the first inner ring 61 has a flange shape protruding from the outer peripheral surface 553 of the holding member 55 over the entire circumference at the end of the holding member 55 on the output side of the rotation axis Ax1. In particular, in this configuration, the holding member 55 and the first inner ring 61 are integrally formed of one metal member, so that the holding member 55 and the first inner ring 61 are handled as one seamless part.

The first bearing member 6 is a component that rotatably supports the plurality of inner pins 4 with respect to the gear body 22 . In other words, the first bearing member 6 is a component for rotatably supporting the rotating member (body portion 11, etc.) with respect to the fixed member (hub member 14, etc.).

The second bearing member 7 is a component that rotatably supports the plurality of inner pins 4 with respect to the gear body 22 . In other words, the second bearing member 7, together with the first bearing member 6, is a component for rotatably supporting the rotating member (body portion 11, etc.) with respect to the fixed member (hub member 14, etc.).

The first bearing member 6 and the second bearing member 7 are arranged side by side in the direction of the rotation axis Ax1, and rotatably support the plurality of inner pins 4 with respect to the gear body 22 at two points in the direction of the rotation axis Ax1. . Here, in this configuration, the first inner ring 61 and the second inner ring 71 are fixed to a fixed member (the hub member 14, etc.), and the first outer ring 62 and the second outer ring 72 are fixed to a rotating member (the trunk portion 11, etc.). ). Therefore, since the inner ring and the outer ring of both the first bearing member 6 and the second bearing member 7 are rotatable relative to each other, the rotating member (body portion 11, etc.) relative to the fixed member (hub member 14, etc.) is rotated. ) is rotatably supported. The first bearing member 6 and the second bearing member 7 will be described in more detail in the section "(3.2) Bearing member".

The eccentric shaft 54 is a cylindrical component, as shown in FIG. The eccentric shaft 54 has an axial center portion 541 and an eccentric portion 542 . Axial portion 541 has a columnar shape in which at least the outer peripheral surface is a perfect circle in plan view. The center (central axis) of the axial portion 541 coincides with the rotation axis Ax1. The eccentric portion 542 has a disc shape with at least an outer peripheral surface that is a perfect circle in a plan view. The center (central axis) of the eccentric portion 542 coincides with the center C1 shifted from the rotation axis Ax1. Here, the distance ΔL (see FIG. 2) between the rotation axis Ax1 and the center C1 is the amount of eccentricity of the eccentric portion 542 with respect to the axial center portion 541 . The eccentric portion 542 has a flange shape that protrudes from the outer peripheral surface of the shaft center portion 541 over the entire circumference at a portion other than both end portions in the longitudinal direction (axial direction) of the shaft center portion 541 . According to the above-described configuration, the eccentric portion 542 of the eccentric shaft 54 performs eccentric motion as the axial portion 541 rotates (rotates) about the rotation axis Ax1.

In this configuration, the axial center portion 541 and the eccentric portion 542 are integrally formed of one metal member, thereby realizing a seamless eccentric shaft 54 . The eccentric shaft 54 having such a shape is combined with the planetary gear 3 together with the eccentric body bearing 5 . Therefore, when the eccentric shaft 54 rotates in a state in which the planetary gear 3 is combined with the eccentric body bearing 5 and the eccentric shaft 54, the planetary gear 3 oscillates around the rotation axis Ax1.

The eccentric body bearing 5 has an eccentric body outer ring 52 and an eccentric body inner ring 51, absorbs the rotation component of the rotation of the eccentric shaft 54, and rotates the eccentric shaft 54 excluding the rotation component of the eccentric shaft 54, that is, the eccentricity It is a component for transmitting only the oscillation component (orbital component) of the shaft 54 to the planetary gear 3 . The eccentric bearing 5 has a plurality of rolling elements 53 (see FIG. 4) in addition to the eccentric outer ring 52 and the eccentric inner ring 51 .

Both the eccentric outer ring 52 and the eccentric inner ring 51 are annular parts. Both the outer ring 52 of the eccentric body and the inner ring 51 of the eccentric body have annular shapes that are perfect circles in a plan view. The eccentric inner ring 51 is one size smaller than the eccentric outer ring 52 and is arranged inside the eccentric outer ring 52 . Here, since the inner diameter of the eccentric outer ring 52 is larger than the outer diameter of the eccentric inner ring 51 , a gap is generated between the inner peripheral surface of the eccentric outer ring 52 and the outer peripheral surface of the eccentric inner ring 51 .

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

Here, the inner diameter of the eccentric inner ring 51 matches the outer diameter of the eccentric portion 542 of the eccentric shaft 54 . The eccentric body bearing 5 is combined with the eccentric shaft 54 in a state in which the eccentric portion 542 of the eccentric shaft 54 is inserted into the eccentric inner ring 51 . Also, the outer diameter of the eccentric outer ring 52 matches the inner diameter (diameter) of the opening 33 in the planetary gear 3 . The eccentric bearing 5 is combined with the planetary gear 3 with the eccentric outer ring 52 fitted in the opening 33 of the planetary gear 3 . In other words, the eccentric body bearing 5 mounted on the eccentric portion 542 of the eccentric shaft 54 is accommodated in the opening 33 of the planetary gear 3 .

In this configuration, as an example, the dimensions in the width direction (the direction parallel to the rotation axis Ax1) of the eccentric inner ring 51 and the eccentric outer ring 52 in the eccentric bearing 5 are both the thickness of the eccentric portion 542 of the eccentric shaft 54 and the thickness of the eccentric portion 542. They are almost identical. Furthermore, the widthwise dimensions of the eccentric inner ring 51 and the eccentric outer ring 52 are larger than the thickness of the planetary gear 3 . Therefore, the planetary gear 3 is accommodated within the range of the eccentric bearing 5 in the direction parallel to the rotation axis Ax1.

When the eccentric shaft 54 rotates in a state where the eccentric bearing 5 and the eccentric shaft 54 are combined with the planetary gear 3, the eccentric inner ring 51 of the eccentric inner ring 51 rotates around the rotation axis Ax1 deviated from the center C1 of the eccentric inner ring 51. The wheel 51 rotates (eccentric motion). At this time, the rotational component of the eccentric shaft 54 is absorbed by the eccentric bearing 5 . Therefore, the eccentric bearing 5 transmits to the planetary gear 3 only the rotation of the eccentric shaft 54 excluding the rotation component of the eccentric shaft 54 , that is, only the oscillation component (revolution component) of the eccentric shaft 54 . Therefore, when the eccentric shaft 54 rotates in a state in which the planetary gear 3 is combined with the eccentric body bearing 5 and the eccentric shaft 54, the planetary gear 3 oscillates around the rotation axis Ax1.

As shown in FIG. 2 , the support 8 is a component that is formed in a ring shape and supports the plurality of inner pins 4 . The support 8 has an annular shape in which at least the outer peripheral surface 81 is a perfect circle in plan view. The support 8 has a plurality of support holes 82 into which the plurality of inner pins 4 are respectively inserted. The support holes 82 are provided in the same number as the inner pins 4, and in this configuration, eight support holes 82 are provided as an example. Each of the plurality of support holes 82 is a hole that opens in a circular shape and penetrates the support 8 along the thickness direction. A plurality of (here, eight) support holes 82 are arranged at equal intervals in the circumferential direction on a virtual circle concentric with the outer peripheral surface 81 of the support 8 . The diameter of the support hole 82 is equal to or larger than the diameter of the inner pin 4 and smaller than the diameter of the loose fitting hole 32 . In this configuration, as an example, the diameter of the support hole 82 is equal to the diameter of the holding hole 551 formed in the holding member 55 . Therefore, the support 8 supports the plurality of inner pins 4 in a state in which each of the plurality of inner pins 4 can rotate. That is, each of the plurality of inner pins 4 is held by both the holding member 55 and the support 8 in a rotatable state.

The support 8 is arranged to face the planetary gear 3 from one side (output side) of the rotation axis Ax1, as shown in FIG. By inserting the plurality of inner pins 4 into the plurality of support holes 82 , the support 8 functions to bundle the plurality of inner pins 4 . Thereby, the support 8 distributes the load applied to the plurality of inner pins 4 when the rotation (rotation component) of the planetary gear 3 is transmitted to the fixed member or the rotating member.

Furthermore, the support 8 is positionally regulated by bringing the outer peripheral surface 81 into contact with the plurality of outer pins 23 . Here, the diameter of the outer peripheral surface 81 of the support 8 is the same as the diameter of the virtual circle (tip circle) passing through the tips of the internal teeth 21 in the internal gear 2 . Therefore, all of the plurality of outer pins 23 contact the outer peripheral surface 81 of the support 8 . Therefore, in a state where the support 8 is positionally regulated by the plurality of outer pins 23, the center of the support 8 is positionally regulated so as to overlap the center of the internal gear 2 (rotational axis Ax1). As a result, the support 8 is centered, and as a result, the plurality of inner pins 4 supported by the support 8 are also centered by the plurality of outer pins 23 .

Moreover, the plurality of outer pins 23 constitute the inner teeth 21 of the internal gear 2 . Therefore, when the gear main body 22 and the plurality of inner pins 4 rotate relative to each other, the support 8 that supports the plurality of inner pins 4 is positioned with respect to the internal gear 2 (the gear main body 22) together with the plurality of inner pins 4. and rotate relative to each other. At this time, since the support 8 is centered by the plurality of outer pins 23, the support 8 is rotated relative to the internal gear 2 while the center of the support 8 is maintained on the rotation axis Ax1. Rotate smoothly. Moreover, the outer peripheral surface 81 of the support 8 rotates relatively to the gear body 22 together with the plurality of inner pins 4 while being in contact with the plurality of outer pins 23 . Therefore, if the gear body 22 of the internal gear 2 is regarded as an "outer ring" and the support 8 as an "inner ring", the plurality of outer pins 23 interposed therebetween function as "rollers". In this way, the support 8 constitutes a needle bearing together with the internal gear 2 (the gear body 22 and the plurality of outer pins 23), enabling smooth rotation.

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

In addition, in this configuration, as shown in FIG. 3, the support 8 is located on the opposite side of the holding member 55 with the planetary gear 3 interposed therebetween. That is, the support 8, the planetary gear 3, and the holding member 55 are arranged side by side in a direction parallel to the rotation axis Ax1. The support 8 supports both ends of the inner pin 4 in the longitudinal direction (direction parallel to the rotation axis Ax1) together with the holding member 55, and the central portion of the inner pin 4 in the longitudinal direction is the idler gear 3 of the planetary gear 3. It is inserted through the fitting hole 32 . In this way, since the support 8 and the holding member 55 support both ends of the inner pin 4 in the longitudinal direction, the inner pin 4 is less likely to tilt. In particular, the plurality of inner pins 4 are likely to receive a bending force (bending moment load) with respect to the rotation axis Ax1.

Further, in this configuration, the support 8 is sandwiched between the planetary gear 3 and the case 10 (cap 12) in the direction parallel to the rotation axis Ax1. As a result, the support 8 is restricted by the case 10 from moving toward the output side (left side in FIG. 9) of the rotation axis Ax1. The movement of the inner pin 4, which passes through the support hole 82 of the support 8 and protrudes from the support 8 toward the output side of the rotation axis Ax1, is restricted by the case 10 as well.

The first bearing 91 and the second bearing 92 are mounted on the axial center portion 541 of the eccentric shaft 54, respectively. Specifically, as shown in FIG. 3, the first bearing 91 and the second bearing 92 are arranged on both sides of the eccentric portion 542 in the axial center portion 541 so as to sandwich the eccentric portion 542 in the direction parallel to the rotation axis Ax1. be worn. The first bearing 91 is arranged on the output side of the rotation axis Ax1 when viewed from the eccentric portion 542 . The second bearing 92 is arranged on the input side of the rotation axis Ax1 when viewed from the eccentric portion 542 . In this configuration, as an example, both the first bearing 91 and the second bearing 92 are deep groove ball bearings using spheres (balls) as rolling elements.

The first bearing 91 is held by the case 10 . Specifically, a circular recess is formed in the surface of the cap 12 on the input side of the rotation axis Ax1. 91 is attached. On the other hand, the second bearing 92 is held by the holding member 55 . Specifically, the second bearing 92 is attached to the holding member 55 by fitting the second bearing 92 into the bearing hole 552 of the holding member 55 . In other words, the second bearing 92 is attached to the gap between the holding member 55 and the eccentric shaft 54 . As a result, the axial center portion 541 of the eccentric shaft 54 is rotatably held at two points on both sides of the eccentric portion 542 in the direction parallel to the rotation axis Ax1.

The balance weight 56 is a component through which the axial center portion 541 of the eccentric shaft 54 is inserted. Here, when the input rotation on the high-speed rotation side accompanies eccentric motion, as in the gear device 1 according to this configuration, if the weight of the rotating body that rotates at high speed is not balanced, it may lead to vibration or the like. . Therefore, the balance weight is provided to balance the weight of the rotating body, which is composed of at least one of the eccentric inner ring 51 and the member (eccentric shaft 54) that rotates together with the eccentric inner ring 51, with respect to the rotation axis Ax1. The balance weight 56 is formed asymmetrically with respect to the rotation axis Ax1, and is formed in a substantially fan shape as an example in this configuration. Here, the balance weight 56 adds weight to the side opposite to the center C1 of the eccentric body outer ring 52 when viewed from the rotation axis Ax1, so that the weight balance of the eccentric shaft 54 is evenly distributed in the circumferential direction from the rotation axis Ax1. acts to bring it closer to

The spacer 93 is a component through which the axial center portion 541 of the eccentric shaft 54 is inserted. The spacer 93 is an annular component and is arranged between the eccentric portion 542 of the eccentric shaft 54 and the first bearing 91 . As a result, a space corresponding to the spacer 93 is secured between the eccentric portion 542 and the first bearing 91 .

Further, the gear device 1 according to this configuration further includes a plurality of oil seals 94, 95, 96 and the like, as shown in FIG. The oil seal 94 is mounted between the hub member 14 and the ring cap 13 and closes the gap between the hub member 14 and the ring cap 13 . The oil seals 95 and 96 are arranged in the through hole 142 of the hub member 14 in a state of being attached to the axial center portion 541 of the eccentric shaft 54 , thereby closing the gap between the hub member 14 and the eccentric shaft 54 . blocking. The internal space of the case 10 sealed by the plurality of oil seals 94, 95, 96 constitutes a sealed space.

A lubricant is injected into the closed space (internal space of the case 10). The lubricant is liquid and is capable of flowing within the enclosed space. Therefore, when the gear device 1 is used, for example, the lubricant enters the meshing portions between the internal teeth 21 formed by the plurality of external pins 23 and the external teeth 31 of the planetary gears 3 . "Liquid" as used in the present disclosure includes liquid or gel substances. The term "gel state" as used herein means a state having properties intermediate between those of a liquid and a solid, and includes a state of colloid consisting of two phases, a liquid phase and a solid phase. For example, there is a state called gel or sol, such as an emulsion in which the dispersion medium is a liquid phase and the dispersoid is a liquid phase, or a suspension in which the dispersoid is a solid phase. Included in "gel-like". The state in which the dispersion medium is a solid phase and the dispersoid is a liquid phase is also included in the “gel state”. As an example in this configuration, the lubricant is liquid lubricating oil (oil).

In the gear device 1 configured as described above, a rotational force as an input is applied to the eccentric shaft 54, and the eccentric shaft 54 rotates about the rotation axis Ax1, causing the planetary gears 3 to oscillate about the rotation axis Ax1. (revolve). At this time, the planetary gear 3 is inscribed with the internal gear 2 inside the internal gear 2 and oscillates with a portion of the external teeth 31 meshing with a portion of the internal teeth 21 . 21 and the external teeth 31 move in the circumferential direction of the internal gear 2 . As a result, relative rotation occurs between the two gears (the internal gear 2 and the planetary gear 3) according to the difference in the number of teeth between the planetary gear 3 and the internal gear 2. The planetary gear 3 is connected to a fixed member (hub member 14, etc.) by a plurality of inner pins 4, and the gear body 22 is fixed to a rotating member (body portion 11, etc.). 2 is extracted from the internal gear 2 . At this time, from the internal gear 2, only the rotation corresponding to the rotation (rotation component) of the planetary gear 3, excluding the oscillation component (revolution component) of the planetary gear 3, is taken out. As a result, from the rotating member to which the gear body 22 is fixed, a rotational output reduced at a relatively high speed reduction ratio is obtained in accordance with the difference in the number of teeth between the two gears.

By the way, in the gear device 1 according to this 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 equation 1. However, here, relative rotation between the planetary gear 3 and the internal gear 2 assumes a case where the gear body 22 is fixed to a rotating member and taken out from the internal gear 2 .

R1=V1/(V1-V2) (Formula 1)
In short, the smaller the tooth number difference (V1-V2) between the internal gear 2 and the planetary gear 3, the larger the reduction ratio R1. As an example, the number of teeth V1 of the internal gear 2 is "30", the number of teeth V2 of the planetary gear 3 is "29", and the difference between the number of teeth (V1-V2) is "1". The speed reduction ratio R1 becomes "30". In this case, when the eccentric shaft 54 rotates around the rotation axis Ax1 clockwise once (360 degrees) as viewed from the input side of the rotation axis Ax1, the gear body 22 rotates around the rotation axis Ax1 with a tooth number difference of "1". '' minutes (that is, about 12.0 degrees).

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

Further, the gear device 1 may include at least the internal gear 2, the planetary gear 3, the plurality of inner pins 4, the first bearing member 6, and the second bearing member 7. For example, A spline bush or the like may be further provided as a component.

(3.2) Bearing member Next, the configurations of the first bearing member 6 and the second bearing member 7 according to this configuration will be described in more detail.

The first bearing member 6 has a first inner ring 61 and a first outer ring 62, as shown in FIGS. The first inner ring 61 and the first outer ring 62 are in a relatively rotatable relationship about the rotation axis Ax1. The first bearing member 6 has a plurality of bearing pins 63 in addition to the first outer ring 62 and the first inner ring 61, as shown in FIGS.

Both the first inner ring 61 and the first outer ring 62 are annular parts, as shown in FIGS. The first inner ring 61 and the first outer ring 62 each have an annular shape that is a perfect circle centered on the rotation axis Ax1 in plan view. The first inner ring 61 is one size smaller than the first outer ring 62 and is arranged inside the first outer ring 62 . Here, since the inner diameter of the first outer ring 62 is larger than the outer diameter of the first inner ring 61, there is a gap between the inner peripheral surface 621 of the first outer ring 62 and the outer peripheral surface 611 (see FIG. 7) of the first inner ring 61. A gap occurs.

The first inner ring 61 is fixed to the holding member 55 as described above. The outer peripheral surface 611 of the first inner ring 61 is formed concentrically with the outer peripheral surface 553 of the holding member 55 in plan view. Particularly in this configuration, the first inner ring 61 is integrated with the holding member 55 , and the flange-shaped portion protruding from the outer peripheral surface 553 of the holding member 55 over the entire circumference constitutes the first inner ring 61 . That is, in FIG. 7 , the outer portion of the outer peripheral surface 553 indicated by the imaginary line (chain two-dot line) corresponds to the first inner ring 61 . Since the holding member 55 is fixed to the hub member 14, the first inner ring 61 is consequently fixed to the fixed member (hub member 14, etc.).

The first outer ring 62 is fixed to the body portion 11, which is a rotating member, as described above. The inner peripheral surface 621 of the first outer ring 62 is formed concentrically with the outer peripheral surface 611 of the first inner ring 61 in plan view. Particularly in this configuration, the first outer ring 62 is integrated with the trunk portion 11 , and a portion of the trunk portion 11 constitutes the first outer ring 62 .

A plurality of bearing pins 63 are arranged between the first inner ring 61 and the first outer ring 62 . The plurality of bearing pins 63 are arranged side by side in the circumferential direction of the first outer ring 62 . The plurality of bearing pins 63 are all metal parts having the same shape, and are provided at equal pitches over the entire circumference of the first outer ring 62 . Each of the plurality of bearing pins 63 is formed in a cylindrical shape. The diameter and length of the multiple bearing pins 63 are common to the multiple bearing pins 63 .

Here, the plurality of bearing pins 63 are held between the first inner ring 61 and the first outer ring 62 in a rotatable state. Since the plurality of bearing pins 63 are sandwiched between the outer peripheral surface 611 of the first inner ring 61 and the inner peripheral surface 621 of the first outer ring 62 , the first outer ring 62 is positioned relative to the first inner ring 61 . , each of the plurality of bearing pins 63 rotates (rotates) as the first outer ring 62 rotates. Therefore, the first bearing member 6 constitutes a needle bearing (needle roller bearing).

In this configuration, the plurality of bearing pins 63 are held on the inner peripheral surface 621 of the first outer ring 62 in a rotatable state. Specifically, as shown in FIG. 9, the inner peripheral surface 621 of the first outer ring 62 is formed with a plurality of grooves over the entire circumference. These plurality of grooves are a plurality of bearing side grooves 622 (see FIG. 7) as holding structures for the plurality of bearing pins 63, respectively. In other words, the structure for holding the plurality of bearing pins 63 includes a plurality of side bearing grooves 622 formed in the inner peripheral surface 621 of the first outer ring 62 . All of the plurality of bearing side grooves 622 have the same shape and are provided at equal pitches. The plurality of bearing side grooves 622 are all parallel to the rotation axis Ax1 and are formed over the entire width of the gear body 22 .

However, in this configuration, since the first outer ring 62 is a part of the body portion 11 as described above, the plurality of bearing side grooves 622 are portions of the body portion 11 corresponding to the first outer ring 62 (see FIG. 10). formed only in The plurality of bearing pins 63 are combined with the first outer ring 62 (body portion 11 ) so as to fit in the plurality of bearing side grooves 622 . Each of the plurality of bearing pins 63 is held in a bearing groove 622 in a rotatable state, and the bearing groove 622 restricts movement of the first outer ring 62 in the circumferential direction.

Thus, since the first bearing member 6 is a needle bearing, the first bearing member 6 is likely to receive loads mainly in the radial direction. Needle bearings have a higher load capacity in the radial direction than deep groove ball bearings or the like. can.

That is, the first bearing member 6 uses, as rolling elements, a plurality of outer pins 23 forming the internal teeth 21 of the internal gear 2 and a plurality of bearing pins 63 basically having the same configuration. Particularly in this configuration, the bearing pins 63 and the outer pins 23 have the same number, diameter, and the like. That is, as shown in FIGS. 4 and 7, 30 outer pins 23 and 30 bearing pins 63 are provided. ) are the same (φ1=φ2).

Furthermore, the outer pin 23 and the bearing pin 63 have the same arrangement when viewed from one side of the rotation axis Ax1 direction. Therefore, the outer pin 23 and the bearing pin 63 are arranged so as to overlap each other in the direction parallel to the rotation axis Ax1. Specifically, a plurality of gear side grooves 222 as a holding structure for the plurality of outer pins 23 formed on the inner peripheral surface 221 of the gear body 22, and a plurality of bearings formed on the inner peripheral surface 621 of the first outer ring 62. A plurality of bearing side grooves 622 as a holding structure for the pin 63 adopts a shared arrangement. That is, the plurality of gear side grooves 222 and the plurality of bearing side grooves 622 are both formed in the gear main body 22 or the first outer ring 62, which are part of the body portion 11, when viewed from one side of the rotation axis Ax1 direction. The arrangement is identical (see FIG. 2). As a result, the outer pin 23 held in the gear groove 222 and the bearing pin 63 held in the bearing groove 622 have the same arrangement when viewed from one side in the rotation axis Ax1 direction.

However, the gear side groove 222 as a holding structure for the outer pin 23 and the bearing side groove 622 as a holding structure for the bearing pin 63 are different in shape. In this configuration, the depth D1 of the gear side groove 222 (see FIG. 4) is greater than the depth D2 of the bearing side groove 622 (see FIG. 7). That is, the gear grooves 222 and the bearing grooves 622 have different depths (D1>D2). Specifically, the gear side groove 222 and the bearing side groove 622 each have an arc-shaped bottom surface with a diameter equal to or larger than the diameter φ1 (=φ2) of the outer pin 23 or the bearing pin 63 when viewed from one direction of the rotation axis Ax1. is a groove. In other words, the bottom surfaces of the gear side groove 222 and the bearing side groove 622 both have a radius of curvature equal to or greater than the radius of the outer pin 23 or the bearing pin 63 . Here, as an example, the bottom surfaces of the gear side groove 222 and the bearing side groove 622 both have the same radius of curvature as the radius of the outer pin 23 or the bearing pin 63 . The bearing side groove 622 is shallower than the gear side groove 222 .

In this configuration, the diameter φ1 of the outer pin 23 and the diameter φ2 of the bearing pin 63 are the same (φ1=φ2). The ratio of depth to diameter is reduced. That is, the ratio (D2/φ2) of the depth D2 to the diameter φ2 of the bearing pin 63 in the bearing groove 622 is smaller than the ratio (D1/φ1) of the depth D1 to the diameter φ1 of the outer pin 23 in the gear groove 222. In this configuration, as an example, the ratio (D1/φ1) of the depth D1 of the gear side groove 222 to the diameter φ1 of the outer pin 23 is "1/2". On the other hand, the ratio (D2/φ2) of the depth D2 of the bearing side groove 622 to the diameter φ2 of the bearing pin 63 is "1/3". Here, at least the ratio (D2/φ2) of the depth D2 of the bearing side groove 622 to the diameter φ2 of the bearing pin 63 is preferably 1/2 or less, more preferably 1/3 or less. Preferably, it may be, for example, about "1/4".

In short, the outer pin 23 is mainly subjected to rotational force around the rotation axis Ax1, whereas the bearing pin 63 is mainly subjected to radial force. , the minimum depth D2 that does not allow the bearing pin 63 to fall off is sufficient. Rather, by reducing the depth D2 of the bearing groove 622, there is an advantage that the frictional resistance between the inner surface of the bearing groove 622 and the bearing pin 63 can be reduced, and the loss in the first bearing member 6 can be reduced. Furthermore, by keeping the depth D2 of the bearing groove 622 small, there is also the advantage that the lubricant can easily enter the bearing groove 622 .

As described above, in this configuration, the outer pin 23 and the bearing pin 63 have the same diameter (diameter) and the same arrangement when viewed from one direction of the rotation axis Ax1. Therefore, in this configuration, the central axis Ax2 (see FIG. 10) that is the center of the rotation (rotation) of the outer pin 23 and the central axis Ax3 (see FIG. 10) of the rotation (rotation) of the bearing pin 63 are the centers. ) and are located on a straight line. In other words, each of the plurality of bearing pins 63 is arranged concentrically with each of the plurality of outer pins 23 .

Further, in this configuration, each of the plurality of bearing pins 63 is separate from each of the plurality of outer pins 23 . The rotation (rotation) of the outer pin 23 and the rotation (rotation) of the bearing pin 63 are asynchronous in the first place. be. In other words, the rotation (rotation) of the outer pin 23 and the rotation (rotation) of the bearing pin 63 are less likely to interfere with each other, and are less likely to interfere with each other's rotation. However, the outer pin 23 and the bearing pin 63 may partially synchronize and rotate.

Further, in this configuration, the outer peripheral surface 611 of the first inner ring 61 has a smaller surface roughness than the one surface adjacent to the outer peripheral surface 611 of the first inner ring 61 . That is, the surface roughness of the outer peripheral surface 611 is smaller than that of both end surfaces of the first inner ring 61 in the direction of the rotation axis Ax1. "Surface roughness" as used in the present disclosure means the degree of roughness of the surface of an object. In this configuration, as an example, the surface roughness is arithmetic mean roughness (Ra). For example, the surface roughness of the outer peripheral surface 611 of the first inner ring 61 is made smaller than that of surfaces other than the outer peripheral surface 611 of the first inner ring 61 by polishing or the like. With this configuration, the rotation of the first outer ring 62 with respect to the first inner ring 61 becomes smoother.

Further, in this configuration, the hardness of the outer peripheral surface 611 of the first inner ring 61 is lower than that of the peripheral surfaces of the plurality of bearing pins 63 and higher than that of the inner peripheral surface 621 of the first outer ring 62 . "Hardness" as used in the present disclosure means the degree of hardness of an object, and the hardness of a metal is represented, for example, by the size of depressions formed by pressing a steel ball with a certain pressure. Specifically, examples of metal hardness include Rockwell hardness (HRC), Brinell hardness (HB), Vickers hardness (HV), Shore hardness (Hs), and the like. Methods for increasing (hardening) the hardness of metal parts include, for example, alloying or heat treatment. In this configuration, as an example, the hardness of the outer peripheral surface 611 of the first inner ring 61 is increased by carburizing and quenching. With this configuration, even when the first outer ring 62 rotates with respect to the first inner ring 61, abrasion powder is less likely to be generated, and smooth rotation of the first bearing member 6 can be easily maintained over a long period of time.

In this way, it is preferable to apply the surface configuration with small surface roughness and high hardness to the outer peripheral surface 81 of the support 8 as well. In other words, in this configuration, the support 8 functions as the "inner ring" of the needle bearing similar to the first bearing member 6, so that the outer peripheral surface 81 of the support 8 corresponding to the outer peripheral surface of the inner ring also has an appropriate surface roughness. Preferably, hardness and hardness are applied.

The second bearing member 7 has a second outer ring 72 and a second inner ring 71, as shown in FIGS. The second inner ring 71 and the second outer ring 72 are in a relatively rotatable relationship about the rotation axis Ax1. The second bearing member 7 has a plurality of second rolling elements 73 in addition to the second outer ring 72 and the second inner ring 71, as shown in FIGS.

Both the second inner ring 71 and the second outer ring 72 are annular parts, as shown in FIG. Both the second inner ring 71 and the second outer ring 72 have annular shapes that are perfect circles centered on the rotation axis Ax1 in plan view. The second inner ring 71 is one size smaller than the second outer ring 72 and is arranged inside the second outer ring 72 . Here, since the inner diameter of the second outer ring 72 is larger than the outer diameter of the second inner ring 71 , a gap is generated between the inner peripheral surface of the second outer ring 72 and the outer peripheral surface of the second inner ring 71 . Furthermore, in this configuration, as shown in FIG. 3, the inner diameter of the second outer ring 72 is larger than the outer diameter of the first inner ring 61 and smaller than the inner diameter of the first outer ring 62 . The outer diameter of the second inner ring 71 is smaller than the outer diameter of the first inner ring 61 .

The second inner ring 71 is fixed to the holding member 55 . Here, the inner diameter of the second inner ring 71 matches the outer diameter of (the outer peripheral surface 553 of) the holding member 55 . The second bearing member 7 is combined with the holding member 55 while the holding member 55 is inserted into the second inner ring 71 . Since the holding member 55 is fixed to the hub member 14, the second inner ring 71 is consequently fixed to the fixed member (hub member 14, etc.).

The second outer ring 72 is fixed to the body portion 11, which is a rotating member. The outer diameter of the second outer ring 72 matches the inner diameter of the outer ring fixing frame 74 (see FIG. 3) of the trunk portion 11 . The second bearing member 7 is combined with the trunk portion 11 in a state in which the second outer ring 72 is fitted in the outer ring fixing frame 74 of the trunk portion 11 . In other words, the second bearing member 7 attached to the holding member 55 is accommodated in the outer ring fixing frame 74 of the trunk portion 11, which is a rotating member.

A plurality of second rolling elements 73 are arranged in a gap between the second inner ring 71 and the second outer ring 72 . The plurality of second rolling elements 73 are arranged side by side in the circumferential direction of the second outer ring 72 . The plurality of second rolling elements 73 are all metal parts having the same shape, and are provided at equal pitches over the entire circumference of the second outer ring 72 . In this configuration, as an example, the second bearing member 7 is a deep groove ball bearing using spherical bodies (balls) as the second rolling elements 73 . That is, the second bearing member 7 includes a deep groove ball bearing.

Since the second bearing member 7 is a deep groove ball bearing, the second bearing member 7 is likely to receive a load mainly in the thrust direction (direction along the rotation axis Ax1). That is, the second bearing member 7 receives a load along at least the direction of the rotation axis Ax1. Although the deep groove ball bearing has a smaller load capacity in the radial direction than a needle bearing, it has a larger load capacity in the thrust direction. The load capacity (load capacity) can be increased.

In short, in the gear device 1 according to this configuration, the provision of the first bearing member 6 and the second bearing member 7 makes it easier to receive a radial load and a thrust load. That is, the gear device 1 can receive the radial load by the first bearing member 6 made of a needle bearing, and the thrust direction load by the second bearing member 7 made of the deep groove ball bearing. Further, the gear device 1 rotatably supports the plurality of inner pins 4 with respect to the gear body 22 at two locations in the direction of the rotation axis Ax1 by the first bearing member 6 and the second bearing member 7 . Therefore, the gear device 1 is likely to receive any bending force (bending moment load) with respect to the rotation axis Ax1.

As described above, the gear device 1 according to this configuration can withstand three kinds of loads, ie, the radial load, the thrust load, and the bending force with respect to the rotation axis Ax1, without using a cross roller bearing. , the required rigidity can be ensured. Moreover, since the load is shared by the first bearing member 6 and the second bearing member 7, the service life of each of the first bearing member 6 and the second bearing member 7 is increased.

Next, the arrangement of the first bearing member 6 and the second bearing member 7 including the relative positional relationship of the first bearing member 6 and the second bearing member 7 will be described with reference to FIGS. 3 and 10. FIG. That is, in this configuration, the first bearing member 6 and the second bearing member 7 rotatably support the plurality of inner pins 4 with respect to the gear body 22 at two locations in the direction of the rotation axis Ax1. Therefore, the first bearing member 6 and the second bearing member 7 are arranged side by side in a direction parallel to the rotation axis Ax1.

In this configuration, as shown in FIG. 3, the internal gear 2, the first bearing member 6, and the second bearing member 7 are arranged in the order from the output side of the rotation axis Ax1: the internal gear 2, the first bearing member 6, the second They are arranged so as to line up in the order of the bearing members 7 . That is, the first bearing member 6 is positioned between the internal gear 2 and the second bearing member 7 in the direction parallel to the rotation axis Ax1. In other words, the first bearing member 6 is located on the same side of the plurality of outer pins 23 as the second bearing member 7 in the direction of the rotation axis Ax1. In this configuration, both the first bearing member 6 and the second bearing member 7 are positioned on the input side (right side in FIG. 3) of the rotation axis Ax1 with respect to the plurality of outer pins 23 .

Furthermore, the plurality of bearing pins 63 are positioned between the second bearing member 7 and the plurality of outer pins 23 in the direction of the rotation axis Ax1. That is, the first bearing member 6 is located on the input side (right side in FIG. 3) of the rotation axis Ax1 with respect to the plurality of outer pins 23, and the second bearing member 7 is located on the rotation axis Ax1 with respect to the first bearing member 6. Located on the input side of Ax1 (right side in FIG. 3). Therefore, the plurality of bearing pins 63 of the first bearing member 6 are sandwiched between the second bearing member 7 and the plurality of outer pins 23 in the direction parallel to the rotation axis Ax1.

Here, the internal gear 2, the first bearing member 6, and the second bearing member 7 are arranged substantially without gaps in the direction parallel to the rotation axis Ax1. Specifically, as shown in FIG. 10, when the body portion 11 is divided into three regions in the direction parallel to the rotation axis Ax1, these three regions are the internal gear 2 and the first bearing member 6, respectively. function as an outer ring fixing frame 74 for fixing the first outer ring 62 and the second bearing member 7 . That is, in this configuration, the gear main body 22, the first outer ring 62, and the outer ring fixing frame 74 form a seamless one component (body portion 11). The gear body 22, the first outer ring 62 and the outer ring fixing frame 74 are separated.

With the arrangement as described above, one end of the plurality of bearing pins 63 in the direction of the rotation axis Ax1 contacts the second outer ring 72 or the second inner ring 71 . Specifically, as shown in FIG. 10 , the end surface of the bearing pin 63 on the input side (right side in FIG. 10 ) of the rotation axis Ax1 contacts the second outer ring 72 of the second bearing member 7 . As a result, the movement of the bearing pin 63 toward the input side of the rotation axis Ax1 is restricted by the second outer ring 72 . Furthermore, the other ends of the plurality of bearing pins 63 in the direction of the rotation axis Ax<b>1 contact the outer pins 23 . Specifically, as shown in FIG. 10 , the end surface of the bearing pin 63 on the output side (left side in FIG. 10 ) of the rotation axis Ax1 contacts the outer pin 23 . As a result, the movement of the bearing pin 63 toward the output side of the rotation axis Ax1 is restricted by the outer pin 23 .

Further, in the gear device 1 according to this configuration, each of the plurality of inner pins 4 has at least a portion thereof extending from the first bearing member 6 and the second bearing member 7 in the axial direction of the first bearing member 6 (rotational axis Ax1 direction). placed in the same position as That is, as shown in FIG. 10, at least a part of the inner pin 4 is arranged at the same position as the first bearing member 6 and the second bearing member 7 in the direction parallel to the rotation axis Ax1.

In other words, at least a portion of each of the plurality of inner pins 4 is arranged inside the first bearing member 6 and the second bearing member 7 . In short, in this configuration, as described above, the plurality of inner pins 4 are positioned inside the second bearing member 7 when viewed from one side in the direction of the rotation axis Ax1. Further, the plurality of inner pins 4 are also positioned inside the first bearing member 6 when viewed from one side in the direction of the rotation axis Ax1 in relation to the first bearing member 6 as well. In this manner, at least a part of each of the plurality of inner pins 4 is arranged at the same position as the first bearing member 6 and the second bearing member 7 in the axial direction of the first bearing member 6, so that the rotation axis Ax1 The dimension of the gear device 1 in the direction parallel to the can be kept small.

Further, the first bearing member 6 and the second bearing member 7 have the following relationship regarding the positional relationship with the holding member 55 that holds the plurality of inner pins 4 . That is, the first bearing member 6 and the second bearing member 7 are positioned outside the holding member 55 when viewed from one side in the direction of the rotation axis Ax1. Specifically, since the first inner ring 61 of the first bearing member 6 has a flange shape that protrudes from the outer peripheral surface 553 of the holding member 55 over the entire circumference, it is positioned outside the holding member 55 when viewed from one direction of the rotation axis Ax1. Located in Since the second bearing member 7 is combined with the holding member 55 in a state where the holding member 55 is inserted into the second inner ring 71, the second bearing member 7 is positioned outside the holding member 55 when viewed from one side in the rotation axis Ax1 direction.

(4) Application Examples Next, application examples of the gear device 1 according to the present configuration will be described with reference to FIG.

The gear device 1 according to this configuration constitutes a wheel device W1 together with the wheel body 102 . In other words, the wheel device W<b>1 according to this configuration includes the gear device 1 and the wheel body 102 . The wheel body 102 rolls on the running surface due to rotational output when the plurality of inner pins 4 rotate relative to the gear body 22 . In this configuration, the body portion 11, the cap 12, and the ring cap 13 as the “rotating member” of the case 10 forming the outer shell of the gear device 1 constitute the wheel main body 102. As shown in FIG. In other words, in the wheel device W1 according to this configuration, the gear device 1 operates with the rotation of the eccentric shaft 54 as input rotation and the rotation of the rotating member (such as the trunk portion 11) to which the gear body 22 is fixed as output rotation. As a result, the wheel body 102 rotates and rolls on the running surface. Here, rubber tires 103, for example, are attached to the contact surface of the wheel body 102 with the running surface, that is, the outer peripheral surface of the body portion 11, which serves as the ground contact surface.

A wheel device W1 using the gear device 1 constitutes a vehicle V1 together with a vehicle body 100, as shown in FIG. 11, for example. In other words, the vehicle V1 according to this configuration includes the wheel device W1 and the vehicle body 100. As shown in FIG. The vehicle body 100 holds the wheel device W1. That is, the vehicle V1 according to this configuration uses the wheel device W1 including the gear device 1 as a wheel, and the wheel main body 102 rotates and rolls on the running surface, thereby running on a flat running surface such as a floor surface. do. In the example of FIG. 11 , a vehicle V1 includes four wheel devices W1, and the wheel devices W1 are attached to the four corners of a vehicle body 100 that is rectangular in plan view. Such a vehicle V1 includes a drive source 101 for applying drive force to the wheel device W1. In the example of FIG. 11, the vehicle V1 is equipped with four drive sources 101, and the drive sources 101 adopt a layout of "in-wheel motors" corresponding to the wheel devices W1 one-to-one.

The driving source 101 generates a driving force for swinging the planetary gear 3 of the gear device 1 included in each wheel device W1. Specifically, the drive source 101 is a power generation source such as a motor (electric motor). Power generated by the drive source 101 is transmitted to the eccentric shaft 54 in the gear device 1 . That is, the drive source 101 causes the planetary gear 3 to oscillate by rotating the eccentric shaft 54 of the corresponding wheel device W1 around the rotation axis Ax1. As a result, the rotation (input rotation) generated by the drive source 101 is reduced at a relatively high speed reduction ratio in the gear device 1, causing the wheel body 102 to rotate with relatively high torque.

In this manner, the vehicle V1 can move in any direction on the traveling surface by individually driving the plurality (here, four) of the wheel devices W1. For example, the vehicle V1 runs in a straight line by rotating the plurality of wheel devices W1 in the same direction at the same speed, and changes its traveling direction by applying a rotation difference between the plurality of wheel devices W1. It is possible to execute a curve traveling or turning etc. Therefore, the vehicle V1 can move forward, backward, turn left and right, and the like. The turn here includes a pivot turn and a super pivot turn.

Thus, the vehicle V1 can freely travel on the travel surface by controlling the drive source 101 by using the wheel device W1 as the drive wheels. In particular, the vehicle V1 according to this configuration is suitable for vehicles that require relatively high torque, such as automated guided vehicles (AGVs). The vehicle V1 as an unmanned guided vehicle autonomously travels on a travel surface with, for example, a transported object loaded on the vehicle body 100. As shown in FIG. This allows the vehicle V1 to transport an article placed at one location to another location.

In this type of vehicle V1, the wheel device W1 needs to support not only the weight of the vehicle body 100 but also the weight of the object to be conveyed loaded on the vehicle body 100. As shown in FIG. In other words, a relatively large load may be applied to the wheel device W1 in the radial direction (direction orthogonal to the rotation axis Ax1) not only when the vehicle V1 is running, but also when the vehicle V1 is stopped. Since the wheel device W1 according to this configuration uses a needle bearing having the bearing pin 63 as a "rolling element (roller)" as the first bearing member 6 of the gear device 1, the load in the radial direction is relatively large. Able to withstand loads.

When the vehicle V1 makes a curve or turns, a load in the thrust direction (in the direction along the rotation axis Ax1) may be applied to the wheel device W1. sufficiently small compared to Moreover, since the wheel device W1 according to this configuration uses a deep groove ball bearing as the second bearing member 7 of the gear device 1, the load in the thrust direction can be received by the second bearing member 7. can. In short, the wheel device W1 using the gear device 1 according to the present configuration is particularly suitable for the vehicle V1, which is likely to receive a relatively large load in the radial direction and not so much in the thrust direction, such as an automatic guided vehicle. is.

Furthermore, in this configuration, the gear device 1 takes out the rotational force of the gear body 22 as an output. will rotate to When the first outer ring 62 rotates, the plurality of bearing pins 63 held in the plurality of bearing side grooves 622 of the first outer ring 62 also rotate about the rotation axis Ax1. As a result, in the first bearing member 6 that mainly receives the load in the radial direction, since the bearing pins 63 positioned in the vertical direction of the rotation axis Ax1 change as needed, the load is applied intensively to some of the bearing pins 63. easy to avoid.

In this configuration, the drive source 101 is not included in the wheel device W1, but the configuration is not limited to this example, and the drive source 101 may be included in the wheel device W1. In this case, the wheel device W1 includes the drive source 101, the gear device 1, and the wheel body 102.

(5) Modifications The basic configuration is just one of the various configurations of the present disclosure. The basic configuration can be variously modified according to the design etc., as long as the object of the present disclosure can be achieved. In addition, the drawings referred to in this disclosure are all schematic diagrams, and the ratio of the size and thickness of each component in the drawings does not necessarily reflect the actual dimensional ratio. . Modifications of the basic configuration are listed below. Modifications described below can be applied in combination as appropriate.

In the basic configuration, the planetary gear 3 exemplifies one type of gear device 1 , but the gear device 1 may include a plurality of planetary gears 3 . For example, when the gear device 1 includes two planetary gears 3, these two planetary gears 3 are preferably arranged with a phase difference of 180 degrees around the rotation axis Ax1. Moreover, when the gear device 1 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. In this way, when the plurality of planetary gears 3 are evenly arranged in the circumferential direction around the rotation axis Ax1, it is possible to balance the weight among the plurality of planetary gears 3.

In addition, the tooth profile and other structures (principles) can also be changed as appropriate. Japanese Patent Application Laid-Open No. 2017-137989). Furthermore, the gear device 1 is, for example, an eccentric oscillation type gear device (see Japanese Patent Application Laid-Open No. 2020-85213 as an example) that converts the rotation of the input gear into eccentric oscillation via the spur gear and the crankshaft. good.

Also, as shown in FIG. 12 , each of the plurality of bearing pins 63 may be integrated with each of the plurality of outer pins 23 . That is, in the example of FIG. 12 , one pin is extended in the axial direction, part of which functions as the bearing pin 63 and the other part functions as the outer pin 23 . In the configuration of this modified example, although the outer pin 23 and the bearing pin 63 rotate together and cannot rotate individually, it is possible to reduce the number of parts.

Moreover, it is not an essential configuration in the gear device 1 that each of the plurality of inner pins 4 is arranged at the same position as the first bearing member 6 or the second bearing member 7 in the direction of the rotation axis Ax1. That is, each of the plurality of inner pins 4 may be arranged in line with (oppose to) the first bearing member 6 or the second bearing member 7 in the direction of the rotation axis Ax1.

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

Moreover, the second bearing member 7 is not limited to a deep groove ball bearing, and may be, for example, a cross roller bearing or an angular ball bearing. Further, the second bearing member 7, for example, like a four-point contact ball bearing, is loaded in the radial direction, the load in the thrust direction (direction along the rotation axis Ax1), and the bending force (bending moment load) with respect to the rotation axis Ax1. ) may be a structure that can withstand any of the above.

In addition to the second bearing member 7, the gear device 1 may further include a bearing member such as a deep groove ball bearing, a cross roller bearing, or an angular ball bearing.

Moreover, the eccentric body bearing 5 is not limited to a deep groove ball bearing, and may be an angular ball bearing or the like, for example. Furthermore, the eccentric bearing 5 is not limited to a ball bearing, and may be a roller bearing such as a cylindrical roller bearing, a needle roller bearing, or a tapered roller bearing, in which the rolling elements 53 are not ball-shaped "rollers". good.

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

Further, the gear device 1 is not limited to the configuration in which the rotational force of the gear body 22 is taken out as an output when the plurality of inner pins 4 rotate relative to the gear body 22 . For example, when the planetary gear 3 is connected to a rotating member by a plurality of inner pins 4 and the gear body 22 is fixed to a fixed member, the plurality of inner pins 4 rotate relative to the gear body 22. , the rotational force (rotational component) of the planetary gear 3 may be taken out as an output.

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

Moreover, the gear device 1 may be provided with inner rollers. That is, in the gear device 1 , it is not essential for each of the plurality of inner pins 4 to directly contact the inner peripheral surface of the loose fitting hole 32 . An inner roller may be interposed therebetween. In this case, the inner roller is mounted on the inner pin 4 and is rotatable around the inner pin 4 . Furthermore, it is not essential for each of the plurality of inner pins 4 to be held by the holding member 55 in a rotatable state.

At least a part of each of the plurality of inner pins 4 may be arranged at the same position as the first bearing member 6 or the second bearing member 7 in the direction of the rotation axis Ax1. For example, each of the plurality of inner pins 4 may be wholly within the range of the first bearing member 6 or the second bearing member 7 in the direction of the rotation axis Ax1.

Further, it is not essential in the gear device 1 that the plurality of inner pins 4 connect the planetary gear 3 to a fixed member (the hub member 14 or the like) via the holding member 55 . For example, the plurality of inner pins 4 may be inserted into holding holes formed in the hub member 14 to directly connect the planetary gear 3 to a fixed member (hub member 14 or the like).

Further, it is not essential in the gear device 1 that the support 8 positions the plurality of inner pins 4 with respect to the support 8 both in the circumferential direction and the radial direction. For example, the support 8 may have slit-shaped support holes 82 extending in the radial direction, and the plurality of inner pins 4 may be positioned with respect to the support 8 only in the circumferential direction. Conversely, the support 8 may position the plurality of inner pins 4 relative to the support 8 only in the radial direction.

Further, like the basic configuration, providing the balance weight 56 is not an essential configuration for the gear device 1 . That is, instead of adding the balance weight 56, the rotor (the eccentric inner ring 51, the eccentric shaft 54, etc.) is lightened to reduce the weight, thereby balancing the weight of the rotor with respect to the rotation axis Ax1. is also possible. According to this configuration, it is possible to suppress vibration and the like caused by the weight balance of the rotating body that rotates at high speed while keeping the number of parts small.

Moreover, the vehicle V1 only needs to have one or more wheel devices W1, and the number of wheel devices W1 is not limited to four (four wheels). As an example, the vehicle V1 may have one to three wheel devices W1, or five or more. Further, the drive source 101 for driving the wheel device W1 is not limited to the one-to-one in-wheel motor layout for the wheel device W1, and one drive source 101 is provided for a plurality of wheel devices W1. may be Further, the wheel device W1 according to the basic configuration may be provided only for the driving wheels of the vehicle V1. For example, the vehicle V1 has one or more driven wheels in addition to the wheel device W1 as the driving wheels. may be provided. The driven wheels are "non-driven wheels" to which power from the drive source 101 is not transmitted and which do not generate driving force for running the vehicle V1.

Further, the vehicle V1 using the wheel device W1 including the gear device 1 according to the basic configuration is not limited to an automatic guided vehicle (AGV), and may be a vehicle other than a transport vehicle such as a surveillance vehicle or a photographing vehicle. good. Further, the vehicle V1 is not limited to an autonomously traveling vehicle that travels unmanned, and may be, for example, a vehicle that is operated (driven) by a person, or a vehicle that is remotely operated by a person.

Further, the gear device 1 according to the basic configuration may be applied not only to the wheel device W1 but also to a robot such as a horizontal articulated robot, a so-called SCARA (Selective Compliance Assembly Robot Arm) type robot. good. In this case, the gear device 1 constitutes an actuator together with a drive source 101 that generates a drive force for swinging the planetary gears 3, and the actuator is mounted on the robot. Further, application examples of the gear device 1 and actuators are not limited to horizontal articulated robots, and may be industrial robots other than horizontal articulated robots, or non-industrial robots. Examples of industrial robots other than horizontal articulated robots include vertical articulated robots and parallel link robots. Examples of non-industrial robots include household robots, nursing care robots, medical robots, and the like.

Moreover, it is not an essential configuration of the gear device 1 that the gear body 22 , the first outer ring 62 and the outer ring fixing frame 74 are integrated as in the basic configuration. For example, the gear body 22, the first outer ring 62, and the outer ring fixing frame 74 are separate bodies (separate parts), and the gear body 22, the first outer ring 62, and the outer ring fixing frame 74 are press-fitted, welded, bonded, or the like. It may be fixed to the body portion 11 by the fixing means.

Moreover, it is not an essential configuration of the gear device 1 that the first inner ring 61 is integrated with the holding member 55 as in the basic configuration. For example, even if the first inner ring 61 and the holding member 55 are separate bodies (separate parts), and the first inner ring 61 is fixed to the holding member 55 by fixing means such as press fitting, welding, or adhesion. good. Furthermore, the second inner ring 71 may be integrated with the holding member 55 .

(Embodiment 1)
As shown in FIGS. 13 and 14, in an internal meshing planetary gear device 1A (hereinafter also simply referred to as a "gear device 1A") according to the present embodiment, a first bearing member 6A has a gear according to a basic configuration. It differs from device 1. Hereinafter, the same reference numerals are given to the same configurations as the basic configuration, and the description thereof will be omitted as appropriate. FIG. 13 is a schematic cross-sectional view of the gear device 1A. 14 is a cross-sectional view taken along line B1-B1 of FIG. 13 and a partially enlarged view thereof. However, in FIG. 14, parts other than the eccentric shaft 54 are not hatched even in the cross section.

By the way, in the related art described above, since the cross roller bearing is used as the bearing member, the cross roller bearing having a relatively complicated structure may hinder the simplification of the structure of the gear device 1 as a whole. . The gear device 1A according to the present embodiment can provide an internal meshing planetary gear device 1A that facilitates structural simplification by the following configuration.

That is, as shown in FIGS. 13 and 14, a gear device 1A according to this embodiment includes an internal gear 2, planetary gears 3, a plurality of inner pins 4, and a first bearing member 6A. The internal gear 2 has an annular gear main body 22 and a plurality of outer pins 23 that are held on an inner peripheral surface 221 of the gear main body 22 in a rotatable state and constitute the internal teeth 21 . The planetary gear 3 has external teeth 31 that partially mesh with the internal teeth 21 . The plurality of inner pins 4 are inserted into the plurality of loose fitting holes 32 formed in the planetary gear 3 and rotate relatively to the gear body 22 while revolving inside the loose fitting holes 32 . The first bearing member 6</b>A has a first inner ring 61 , a first outer ring 62 and a plurality of bearing pins 63 . A plurality of bearing pins 63 are held between the first inner ring 61 and the first outer ring 62 in a rotatable state. Here, the plurality of outer pins 23 and the plurality of bearing pins 63 have different diameters and different holding structures.

According to this aspect, the first bearing member 6</b>A has a first inner ring 61 , a first outer ring 62 and a plurality of bearing pins 63 . That is, the first bearing member 6A is a needle bearing having the bearing pin 63 as a "roller" and can withstand a relatively large load in the radial direction. Moreover, since the diameters of the plurality of outer pins 23 and the plurality of bearing pins 63 are different and the holding structures are also different, depending on the setting of the diameter of the bearing pins 63 and the holding structure, the bearing pins 63 can withstand various assumed loads. easier. Therefore, the gear device 1A according to the present embodiment has an advantage that the structure can be easily simplified as compared with the related art that uses a cross roller bearing as a bearing member.

That is, the plurality of outer pins 23 and the plurality of bearing pins 63 have different diameters. In this embodiment, the ratio of the diameter φ2 (see FIG. 14) to the length of the bearing pin 63 in the first bearing member 6A is greater than in the basic configuration. That is, in this embodiment, a thick pin is used as the bearing pin 63 . Therefore, as shown in FIG. 13 , the bearing pin 63 has a larger diameter than the outer pin 23 . In other words, the diameter φ2 of the bearing pin 63 is larger than the diameter φ1 of the outer pin 23 (see FIG. 4). Therefore, in the first bearing member 6A according to the present embodiment, compared with the first bearing member 6 according to the basic configuration, the load resistance (load capacity) in the radial direction can be increased. The load capacity (load capacity) of the can be increased.

Further, in the present embodiment, the plurality of outer pins 23 and the plurality of bearing pins 63 have different holding structures. In the present disclosure, “different holding structures” means that there is some difference between the holding structure for holding the outer pin 23 and the holding structure for holding the bearing pin 63 . As an example, as described in the basic configuration, the gear groove 222 as a holding structure for the outer pin 23 and the bearing groove 622 as a holding structure for the bearing pin 63 have different shapes (depths). included in "having a different holding structure". As another example, “different holding structures” also includes a case where the plurality of outer pins 23 and the plurality of bearing pins 63 have different properties such as the material or hardness of the holding structure.

In this embodiment, the depth D1 of the gear side groove 222 (see FIG. 4) is greater than the depth D2 of the bearing side groove 622 (see FIG. 14). That is, the gear grooves 222 and the bearing grooves 622 have different depths (D1>D2). Specifically, the bearing side groove 622 is a groove having an arc-shaped bottom surface with a diameter equal to or larger than the diameter φ2 (>φ1) of the bearing pin 63 when viewed from one side in the direction of the rotation axis Ax1. In other words, the bottom surface of the bearing groove 622 has a larger radius of curvature than the bottom surface of the gear groove 222 . Here, as an example, the bottom surface of the bearing side groove 622 has the same radius of curvature as the radius of the bearing pin 63 . Moreover, the bearing side groove 622 is shallower than the gear side groove 222 .

In this embodiment, although the diameter φ1 of the outer pin 23 and the diameter φ2 of the bearing pin 63 are different (φ1<φ2), the plurality of bearing side grooves 622 have a larger diameter of the pin to be held than the plurality of gear side grooves 222. The ratio of depth to diameter is set small. That is, the ratio of the depth D2 to the diameter φ2 of the bearing pin 63 in the bearing groove 622 (D2/φ2) is smaller than the ratio of the depth D1 to the diameter φ1 of the outer pin 23 in the gear groove 222 (D1/φ1). In this embodiment, as an example, the ratio (D2/φ2) of the depth D2 of the bearing side groove 622 to the diameter φ2 of the bearing pin 63 is "1/4" or less.

In short, in this embodiment, the difference between the retaining structure for the outer pin 23 (gear side groove 222) and the retaining structure for the bearing pin 63 (bearing side groove 622) is not only the difference in depth (D1 and D2), but also the bottom surface. also includes the difference in the radius of curvature of In this way, if the gear groove 222 and the bearing groove 622 have different shapes, the processing for forming the gear groove 222 and the bearing groove 622 on the body 11 becomes complicated, but the outer pin 23 and the outer pin 23 having different diameters Each bearing pin 63 can be securely held.

Further, in the present embodiment, since the outer pin 23 and the bearing pin 63 have different diameters (diameters), the central axis Ax2, which is the center when the outer pin 23 rotates (rotates), and the bearing pin 63 rotate ( The central axis Ax3, which is the center of rotation), is displaced from each other. In other words, each of the plurality of bearing pins 63 is not arranged concentrically with each of the plurality of outer pins 23 . In the present embodiment, as shown in FIG. 13, the central axis Ax3 of the bearing pin 63 is located inside (rotational axis Ax1) side of the central axis Ax2 of the outer pin 23 .

Furthermore, in the present embodiment, the diameter of (the outer peripheral surface 81 of) the support 8 is one size smaller than the diameter of the virtual circle (tip circle) passing through the tips of the internal teeth 21 in the internal gear 2 . Therefore, the outer peripheral surface 81 of the support 8 is not in contact with the plurality of outer pins 23 , and gaps are generated between the outer peripheral surface 81 of the support 8 and the plurality of outer pins 23 .

As a modification of the first embodiment, each of the plurality of bearing pins 63 may be integrated with each of the plurality of outer pins 23 as shown in FIG. 15 . That is, in the example of FIG. 15 , one pin is extended in the axial direction, a part of which functions as the bearing pin 63 and another part of which functions as the outer pin 23 . Here, since the diameter φ2 of the bearing pin 63 and the diameter φ1 of the outer pin 23 are different, the central axis Ax2, which is the center when the outer pin 23 rotates (rotates), and the diameter φ1 when the bearing pin 63 rotates (rotates) are arranged on a straight line with the central axis Ax2 that is the center of the . Thereby, the pin formed by integrating the outer pin 23 and the bearing pin 63 can be rotated around the central axis Ax2. In the configuration of this modified example, although the outer pin 23 and the bearing pin 63 rotate together and cannot rotate individually, it is possible to reduce the number of parts.

As another modification of the first embodiment, the second bearing member 7 can be omitted as appropriate. That is, the gear device 1A only needs to include the internal gear 2, the planetary gear 3, the plurality of inner pins 4, and the first bearing member 6A, and the second bearing member 7 may be omitted. .

As another modification of Embodiment 1, the diameter φ2 of the bearing pin 63 may be smaller than the diameter φ1 of the outer pin 23 . Furthermore, the numbers of the bearing pins 63 and the outer pins 23 may be different.

As another modification of the first embodiment, the diameter of the outer peripheral surface 81 of the support 8 may be the same as the diameter of the virtual circle (tip circle) passing through the tips of the internal teeth 21 in the internal gear 2. good. In this case, as in the basic configuration, the support 8 is positionally regulated by bringing the outer peripheral surface 81 into contact with the plurality of outer pins 23 .

The configuration (including modifications) of the first embodiment can be applied in appropriate combination with the configurations (including modifications) described in the basic configuration.

(Embodiment 2)
As shown in FIGS. 16 and 17, in an internal meshing planetary gear device 1B (hereinafter also simply referred to as a "gear device 1B") according to the present embodiment, the configuration of a first bearing member 6B is the same as that of the first embodiment. It differs from the gear device 1A. In the following, configurations similar to those of the first embodiment are denoted by common reference numerals, and descriptions thereof are omitted as appropriate. FIG. 16 is a schematic cross-sectional view of the gear device 1B. 17 is a cross-sectional view taken along line B1-B1 of FIG. 16 and a partially enlarged view thereof. However, in FIG. 17, parts other than the eccentric shaft 54 and the retainer 64 are omitted from hatching even in cross sections.

In this embodiment, the first bearing member 6B is configured so that the plurality of bearing pins 63 can move relative to the first outer ring 62 in the circumferential direction of the first outer ring 62 . On the other hand, in the internal gear 2 , the plurality of outer pins 23 are restricted from moving in the circumferential direction of the gear body 22 relative to the gear body 22 , as in the first embodiment. Therefore, the plurality of bearing pins 63 can move in the circumferential direction of the first outer ring 62 relative to the plurality of outer pins 23 . As a result, in the gear device 1B according to this embodiment, as the plurality of inner pins 4 rotate relative to the gear body 22, the plurality of bearing pins 63 rotate relative to the plurality of outer pins 23. and rotate relative to each other.

Specifically, the first bearing member 6B has a retainer 64 (retainer) as shown in FIG. The plurality of bearing pins 63 are rotatably arranged between the inner peripheral surface 621 of the first outer ring 62 and the outer peripheral surface 611 of the first inner ring 61 and held by the retainer 64 . The retainer 64 retains the plurality of bearing pins 63 at equal pitches in the circumferential direction of the first outer ring 62 . Further, the retainer 64 is not fixed to the inner peripheral surface 621 of the first outer ring 62 and the outer peripheral surface 611 of the first inner ring 61, and rotates around the rotation axis Ax1. are rotatable relative to each of the As a result, the plurality of bearing pins 63 held by the cage 64 move in the circumferential direction of the first outer ring 62 as the cage 64 rotates. In other words, the retaining structure for the plurality of bearing pins 63 includes the retainer 64 arranged between the first outer ring 62 and the first inner ring 61 . The retainer 64 is made of metal, for example.

In short, in this embodiment, the retaining structure for the outer pin 23 is the gear side groove 222, whereas the retaining structure for the bearing pin 63 is the retainer 64. are different in terms of method. In this case, only the gear side groove 222 needs to be formed as a holding structure for the body portion 11, and the processing of the body portion 11 is facilitated.

As a modification of the second embodiment, the diameter φ2 of the bearing pin 63 may be the same as the diameter φ1 of the outer pin 23 (φ1=φ2), or the diameter φ2 of the bearing pin 63 may be larger than the diameter φ1 of the outer pin 23. It can be small.

As another modification of the second embodiment, as the inner pins 4 rotate relative to the gear body 22, the bearing pins 63 rotate relative to the outer pins 23. If possible, retainer 64 is not essential. Further, the material of the retainer 64 is not limited to metal, and may be resin such as engineering plastic.

The configuration (including modifications) of the second embodiment can be applied in appropriate combination with the basic configuration or the configuration (including modifications) described in the first embodiment.

(summary)
As described above, the internally meshing planetary gear device (1, 1A, 1B) according to the first aspect includes an internal gear (2), a planetary gear (3), and a plurality of inner pins (4). , and a first bearing member (6, 6A, 6B). The internal gear (2) comprises an annular gear body (22) and a plurality of external pins ( 23) and The planetary gear (3) has external teeth (31) that partially mesh with the internal teeth (21). A plurality of inner pins (4) are inserted into a plurality of loose fitting holes (32) formed in the planetary gear (3), and revolve in the loose fitting holes (32) to rotate the gear body (22). Rotate relative to The first bearing members (6, 6A, 6B) rotatably support the plurality of inner pins (4) with respect to the gear body (22). The first bearing member (6, 6A, 6B) has a first inner ring (61), a first outer ring (62), and a plurality of bearing pins (63). A plurality of bearing pins (63) are held between the first inner ring (61) and the first outer ring (62) in a rotatable state. The plurality of outer pins (23) and the plurality of bearing pins (63) have different diameters and different holding structures.

According to this aspect, the first bearing members (6, 6A, 6B) are needle bearings having the bearing pins (63) as "rolling elements (rollers)", and the load in the radial direction is relatively large. can withstand. Moreover, the plurality of outer pins (23) and the plurality of bearing pins (63) have different diameters and different holding structures. It becomes easier to withstand various loads that Therefore, there is an advantage that it is easy to simplify the structure.

In the internally meshing planetary gear device (1, 1A, 1B) according to the second aspect, in the first aspect, the structure for holding the plurality of outer pins (23) is provided on the inner peripheral surface (221) of the gear body (22). ) and a plurality of gear grooves (222) formed therein. The holding structure for the plurality of bearing pins (63) includes a plurality of side bearing grooves (622) formed in the inner peripheral surface (621) of the first outer ring (62). The plurality of gear side grooves (222) and the plurality of bearing side grooves (622) have different depths.

According to this aspect, it is possible to realize different holding structures for the plurality of outer pins (23) and the plurality of bearing pins (63) due to the difference in depth between the gear groove (222) and the bearing groove (622).

The internally meshing planetary gear device (1, 1A, 1B) according to the third aspect is characterized in that, in the first aspect, the plurality of inner pins (4) rotate relative to the gear body (22). Accordingly, the plurality of bearing pins (63) rotate relative to the plurality of outer pins (23).

According to this aspect, since the positions of the plurality of bearing pins (63) change relative to the plurality of outer pins (23), a concentrated load is less likely to be applied to some of the bearing pins (63). .

In the internal meshing planetary gear device (1, 1A, 1B) according to the fourth aspect, in the third aspect, the structure for holding the plurality of bearing pins (63) includes the first outer ring (62) and the first inner ring ( 61) and a retainer (64) disposed between the

According to this aspect, the retainer (64) can maintain the pitch of the plurality of bearing pins (63).

In the internally meshing planetary gear device (1, 1A, 1B) according to the fifth aspect, in any one of the first to fourth aspects, each of the plurality of bearing pins (63) includes a plurality of outer pins (23) are arranged concentrically with each of the

According to this aspect, it is easy to synchronize the rotation of the bearing pin (63) and the rotation of the outer pin (23).

In the internal meshing planetary gear device (1, 1A, 1B) according to the sixth aspect, in any one of the first to fifth aspects, each of the plurality of bearing pins (63) includes a plurality of outer pins (23) is one with each of the

According to this aspect, it is easy to reduce the number of parts.

An internally meshing planetary gear device (1, 1A, 1B) according to a seventh aspect, in any one of the first to sixth aspects, further includes a second bearing member (7). The second bearing member (7), together with the first bearing members (6, 6A, 6B), rotates the plurality of inner pins (4) with respect to the gear body (22) at two points in the direction of the rotation axis (Ax1). Support possible.

According to this aspect, compared to a single point support in which a plurality of inner pins (4) are supported with respect to the gear body (22) at one point in the direction of the rotation axis (Ax1), the bending force with respect to the rotation axis (Ax1) is reduced. It is easy to withstand loads such as (bending moment load).

In the internal meshing planetary gear device (1, 1A, 1B) according to the eighth aspect, in the seventh aspect, the plurality of inner pins (4) are arranged in the second bearing when viewed from one of the rotation axis (Ax1) directions. Located inside member (7).

According to this aspect, the limited space inside the plurality of inner pins (4) can have a relatively simple structure.

A ninth aspect of the internally meshing planetary gear device (1, 1A, 1B) according to the seventh or eighth aspect is characterized in that the first bearing members (6, 6A, 6B) are attached to the plurality of outer pins (23). On the other hand, it is located on the same side in the direction of the rotation axis (Ax1) as the second bearing member (7).

According to this aspect, it is possible to effectively support the plurality of inner pins (4) at two points, and it is easy to reduce the size in the direction of the rotation axis (Ax1).

In the internally meshing planetary gear device (1, 1A, 1B) according to the tenth aspect, in any one of the first to ninth aspects, the structure for holding the plurality of outer pins (23) is provided on the gear body (22). It includes a plurality of gear side grooves (222) formed in the inner peripheral surface (221). The holding structure for the plurality of bearing pins (63) includes a plurality of side bearing grooves (622) formed in the inner peripheral surface (621) of the first outer ring (62). The plurality of bearing grooves (622) have a smaller depth to diameter ratio of the pin they hold than the plurality of gear grooves (222).

According to this aspect, it is easy to reduce the frictional resistance between the inner surface of the bearing groove (622) and the bearing pin (63).

An internally meshing planetary gear device (1, 1A, 1B) according to an eleventh aspect is characterized in that, in any one of the first to tenth aspects, the plurality of inner pins (4) are relative to the gear body (22). It is configured to take out the rotational force of the gear body (22) as an output when the gear body (22) rotates.

According to this aspect, the gear body (22) or a member integrated with the gear body (22) can be used as the rotating member.

A wheel device (W1) according to a twelfth aspect comprises an internal meshing planetary gear device (1, 1A, 1B) according to any one of the first to eleventh aspects, and a plurality of internal gears for a gear body (22). and a wheel body (102) that rolls on the running surface by rotational output when the pins (4) rotate relatively.

According to this aspect, there is an advantage that the structure can be easily simplified.

A vehicle (V1) according to a thirteenth aspect includes the wheel device (W1) according to the twelfth aspect and a vehicle body (100) holding the wheel device (W1).

According to this aspect, there is an advantage that the structure can be easily simplified.

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

Reference Signs List 1, 1A, 1B internally meshing planetary gear device 2 internal gear 3 planetary gear 4 inner pin 6, 6A, 6B first bearing member 7 second bearing member 21 internal tooth 22 gear body 23 outer pin 31 external tooth 32 loose fit Hole 61 First inner ring 62 First outer ring 63 Bearing pin 64 Cage 71 Second inner ring 72 Second outer ring 100 Vehicle body 102 Wheel main body 221 Inner peripheral surface (of gear main body) 222 Gear side groove 621 Inner peripheral surface (of first outer ring) 622 Bearing side groove Ax1 Rotating shaft V1 Vehicle W1 Wheel device

Claims (13)

an internal gear having an annular gear body and a plurality of external pins that are held on the inner peripheral surface of the gear body in a rotatable state and form internal teeth;
a planetary gear having external teeth that partially mesh with the internal teeth;
a plurality of inner pins that are inserted into a plurality of loose fitting holes formed in the planetary gear and rotate relatively to the gear body while revolving in the loose fitting holes;
a first bearing member that rotatably supports the plurality of inner pins with respect to the gear body;
The first bearing member is
a first inner ring and a first outer ring;
a plurality of bearing pins held between the first inner ring and the first outer ring in a rotatable state;
The plurality of outer pins and the plurality of bearing pins have different diameters and different holding structures,
Inscribed planetary gear system. The holding structure for the plurality of outer pins includes a plurality of gear side grooves formed on the inner peripheral surface of the gear body,
The holding structure for the plurality of bearing pins includes a plurality of bearing side grooves formed on the inner peripheral surface of the first outer ring,
The plurality of gear side grooves and the plurality of bearing side grooves have different depths,
The internally meshing planetary gear system according to claim 1. The plurality of bearing pins rotate relative to the plurality of outer pins as the plurality of inner pins rotate relative to the gear body;
The internally meshing planetary gear system according to claim 1. The retaining structure for the plurality of bearing pins includes a retainer disposed between the first outer ring and the first inner ring,
The internally meshing planetary gear system according to claim 3. each of the plurality of bearing pins is arranged concentrically with each of the plurality of outer pins;
The internal meshing planetary gear device according to any one of claims 1 to 4. each of the plurality of bearing pins is integral with each of the plurality of outer pins;
The internal meshing planetary gear device according to any one of claims 1 to 5. Further comprising a second bearing member that rotatably supports the plurality of inner pins with respect to the gear body at two locations in the rotation axis direction together with the first bearing member,
The internal meshing planetary gear device according to any one of claims 1 to 6. The plurality of inner pins are positioned inside the second bearing member when viewed from one of the rotation axis directions,
The internal meshing planetary gear system according to claim 7. The first bearing member is positioned on the same side of the plurality of outer pins as the second bearing member in the rotation axis direction,
The internal meshing planetary gear system according to claim 7 or 8. The holding structure for the plurality of outer pins includes a plurality of gear side grooves formed on the inner peripheral surface of the gear body,
The holding structure for the plurality of bearing pins includes a plurality of bearing side grooves formed on the inner peripheral surface of the first outer ring,
The plurality of bearing side grooves have a smaller depth ratio to the diameter of the pin to be held than the plurality of gear side grooves.
The internal meshing planetary gear device according to any one of claims 1 to 9. When the plurality of inner pins rotate relative to the gear body, the rotational force of the gear body is output as an output,
The internal meshing planetary gear device according to any one of claims 1 to 10. an internal meshing planetary gear device according to any one of claims 1 to 11;
a wheel body that rolls on a running surface by rotation output when the plurality of inner pins rotate relative to the gear body,
wheel device. A wheel device according to claim 12;
a vehicle body that holds the wheel device;
vehicle.

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