JP2017160940A - Gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retain bearing rollers of a gear device at further low cost.SOLUTION: A gear device 12 comprises: a casing 20; a carrier 24 rotating relatively to the casing; and a main bearing 30 disposed between the casing and the carrier. The main bearing includes: an inner race 32 provided in the carrier; an outer ring 34 provided in the casing; a plurality of rollers 36 disposed between the inner race and the outer ring; and a retainer 38 for retaining the plurality of rollers. The plurality of rollers have a rotating axis S36 inclined with respect to a shaft center C30 of the main bearing; on the outer peripheral surface of the inner race and the inner peripheral surface of the outer ring, there are no ribs for limiting the movement of the rollers in the rotational axis direction; a snap ring 40 is disposed in the casing or the carrier; and the retainer is in direct contact with the snap ring, alternatively is in contact with the snap ring via a spacer 70.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a gear device.

  Patent Document 1 discloses a gear device that includes a casing, a carrier that rotates relative to the casing, and a bearing that is disposed between the casing and the carrier.

  The bearing of this gear device includes an inner ring provided in the carrier, an outer ring provided in the casing, a plurality of rollers disposed between the inner ring and the outer ring, and a retainer that holds the plurality of rollers. . The plurality of rollers have a rotation shaft inclined with respect to the shaft center of the bearing.

  In this bearing, a rib (protrusion) for restricting the movement of the roller in the rotation axis direction is not provided on the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring. In the gear device of Patent Document 1, a groove that accommodates the end portion on the large diameter side of the retainer is provided in one of the casing and the carrier, and the retainer continues to stay in the groove, thereby moving the roller in the rotation axis direction. Restrained.

Japanese Patent Laying-Open No. 2015-137705 (FIGS. 1 and 2)

  In the gear device, a groove for accommodating the end portion on the large diameter side of the retainer is formed in one of the casing and the carrier. For this reason, it is necessary to process a wide groove with high precision for a casing (which is a large member) or a carrier, and there is a problem that the cost tends to be high.

  The present invention has been made to solve such a conventional problem, and an object thereof is to hold the roller of the bearing of the gear device at a lower cost.

  The present invention relates to a gear device comprising a casing, a carrier that rotates relative to the casing, and a bearing disposed between the casing and the carrier, wherein the bearing is an inner ring provided in the carrier. And an outer ring provided in the casing, a plurality of rollers disposed between the inner ring and the outer ring, and a retainer that holds the plurality of rollers, wherein the plurality of rollers are shafts of the bearings. A rotating shaft that is inclined with respect to the center, and the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring are not provided with ribs that restrict movement of the rollers in the direction of the rotating shaft, and the casing or The carrier is provided with a retaining ring, and the retainer is configured to abut against the retaining ring directly or abut against the retaining ring via a spacer. Than is.

  In the present invention, a retaining ring is disposed on the casing or the carrier, and the retainer abuts directly on the retaining ring or abuts on the retaining ring via a spacer. Therefore, it is not necessary to process the casing or the carrier at high cost.

  According to the present invention, the roller of the bearing of the gear device can be held at a lower cost.

Sectional drawing which shows the structure of the gear apparatus which shows an example of embodiment of this invention. 1 is an enlarged cross-sectional view of the main part of FIG. The principal part expanded sectional view equivalent to FIG. 2 which shows the modification of FIG. The principal part expanded sectional view equivalent to FIG. 2 which shows the modification of FIG. FIG. 2 is an enlarged cross-sectional view of an essential part corresponding to FIG. FIG. 2 is an enlarged cross-sectional view of an essential part corresponding to FIG.

  Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

  FIG. 1 is a cross-sectional view illustrating a configuration of a gear device according to an example of an embodiment of the present invention. The gear device 12 is a gear device called an “eccentric oscillating type” in which the external gear 14 is in mesh with the internal gear 16 while being oscillated.

  Describing from the outline, the gear device 12 includes a casing 20, a first carrier 24 that rotates relative to the casing 20, a first main bearing 30 that is disposed between the casing 20 and the first carrier 24, Is provided.

  The first main bearing 30 includes a first inner ring 32 provided on the first carrier 24, a first outer ring 34 provided on the casing 20, and a plurality of second inner rings arranged between the first inner ring 32 and the first outer ring 34. One roller (rolling element) 36 and a first retainer 38 that holds the plurality of first rollers 36 are provided.

  The plurality of first rollers 36 have a rotation axis S 36 that is inclined with respect to the axis C 30 of the first main bearing 30. In this embodiment, the outer peripheral surface of the first inner ring 32 and the inner peripheral surface of the first outer ring 34 are not provided with ribs that restrict the movement of the first roller 36 in the direction of the rotation axis S36.

  The gear device 12 includes a casing 20, a second carrier 124 that rotates relative to the casing 20, and a second main bearing 130 that is disposed between the casing 20 and the second carrier 124.

  The second main bearing 130 includes a plurality of second inner rings 132 provided on the second carrier 124, a second outer ring 134 provided on the casing 20, and a plurality of second inner rings 132 disposed between the second inner ring 132 and the second outer ring 134. Two rollers (rolling elements) 136 and a second retainer 138 that holds the plurality of second rollers 136 are provided.

  The plurality of second rollers 136 have a rotation axis S136 inclined with respect to the axis C130 of the second main bearing 130. In this embodiment, the outer peripheral surface of the second inner ring 132 and the inner peripheral surface of the second outer ring 134 are not provided with ribs that restrict the movement of the second roller 136 in the direction of the rotation axis S136.

  In this embodiment, the pair of first and second main bearings 30 and 130 are disposed between the casing 20 and the first and second carriers 24 and 124 in a back-to-back manner. A first retaining ring 40 is disposed on the first carrier 24. The first retainer 38 is in direct contact with the first retaining ring 40. A second retaining ring 140 is disposed on the second carrier 124. The second retainer 138 is in direct contact with the second retaining ring 140.

  More specific description will be given below.

  The gear device 12 includes a plurality of crankshafts 42 disposed at positions offset by R42 from the axis C16 of the internal gear 16. In this example, three crankshafts 42 are incorporated at intervals of 120 ° in the circumferential direction (only one is shown).

  The crankshaft 42 is formed with two eccentric portions 44 having an outer periphery that is eccentric with respect to the axial center C42 of the crankshaft 42 in the same axial position. The eccentric portions 44 located at the same position in the axial direction of the crankshafts 42 have the same eccentricity phase. The eccentric phase difference between the two eccentric portions 44 is 180 ° in this example (eccentric in a direction away from each other).

  A crankshaft gear 46 for inputting power is connected to each crankshaft 42 via a spline 47. Each crankshaft gear 46 meshes simultaneously with an input gear 50 provided on an input shaft (not shown).

  On the other hand, the external gear 14 is incorporated on the outer periphery of the eccentric portion 44 of the crankshaft 42 via the eccentric portion bearing 52. The external gear 14 is in mesh with the internal gear 16. In this embodiment, the internal gear 16 is an internal gear main body 16A integrated with the casing 20, and a pin member that is rotatably incorporated in the internal gear main body 16A and constitutes internal teeth of the internal gear 16. 16B. The number of teeth of the internal gear 16 (the number of pin members 16B) is slightly larger (one in this example) than the number of teeth of the external gear 14.

  A pair of first and second carriers 24 and 124 are disposed on both axial sides of the two external gears 14 and 14. A carrier pin 54 projects integrally from the load-side second carrier 124. The carrier pin 54 penetrates the external gear 14 without contact.

  The pair of first and second carriers 24 and 124 are connected and integrated by a carrier bolt (not shown: only the knock pin 56 is shown) via a carrier pin 54 to constitute an output body having a large mass. The pair of first and second carriers 24 and 124 are supported by the casing 20 via a pair of first and second main bearings 30 and 130 that are assembled back to back. The configuration of the first and second main bearings 30 and 130 will be described in detail later.

  In the present embodiment, a first arm (not shown) of the robot is connected to the casing 20 via a connecting bolt (only the bolt hole 20B is shown). A second arm (not shown) of the robot is connected to the second carrier 124 on the load side via a bolt (not shown).

  Each crankshaft 42 is supported by the pair of first and second carriers 24 and 124 via a pair of first and second tapered roller bearings 58 and 158 that are assembled face to face.

  Next, the configuration in the vicinity of the first and second main bearings 30 and 130 will be described in detail.

  The first main bearing 30 disposed on the first carrier 24 on the non-load side and the second main bearing 130 disposed on the second carrier 124 on the load side include the first main bearing 30 and the second main bearing 130 in the axial direction. It is configured symmetrically with respect to the plane P14 that is equidistant from the bearing 130 (having a similar configuration).

  Therefore, here, the description will focus on the configuration in the vicinity of the first main bearing 30 disposed between the casing 20 and the first carrier 24 on the anti-load side, and the casing 20 and the second carrier on the load side will be described. About the structure of the 2nd main bearing 130 vicinity arrange | positioned between 124, the last 2 digits attach | subject the same code | symbol to the main site | part in a figure, and duplication description is abbreviate | omitted.

  FIG. 2 is an enlarged cross-sectional view of a main part in which the vicinity of the first main bearing 30 of the first carrier 24 on the counterload side in FIG. 1 is enlarged.

  The first main bearing 30 is an angular roller bearing. The first main bearing 30 includes a first inner ring 32 provided on the first carrier 24, a first outer ring 34 provided on the casing 20, and a plurality of second inner rings arranged between the first inner ring 32 and the first outer ring 34. One roller 36 and a first retainer 38 that holds the plurality of first rollers 36 are provided.

  In this embodiment, the first inner ring 32 of the first main bearing 30 is integrated with the first carrier 24 by the same member as the first carrier 24. The first outer ring 34 of the first main bearing 30 is composed of a member different from the casing 20. However, the first inner ring 32 of the first main bearing 30 may be configured by a member different from the first carrier 24, and conversely, the first outer ring 34 is configured integrally by the same member as the casing 20. May be.

  In other words, the concept of “first inner ring 32 provided on the first carrier 24” includes a form in which the first inner ring 32, which is a separate member from the first carrier 24, is fixed to the first carrier 24, and Both the form in which the first carrier 24 itself functions as the first inner ring 32 by processing the outer peripheral surface of the first carrier 24 as in the configuration example is included.

  Further, the concept of “first outer ring 34 provided in the casing 20” includes a configuration in which the first outer ring 34, which is a member different from the casing 20, is fixed to the casing 20 as in this configuration example, Both the form in which the casing 20 itself functions as the first outer ring 34 by processing the peripheral surface is included.

  Since the first inner ring 32 of the first main bearing 30 in this configuration example is integrated with the first carrier 24, the first carrier 24 itself has the inner ring rolling surface 32C of the first main bearing 30 on the outer periphery. It has one. The inner ring rolling surface 32C has an angle of θ (45 ° in this example) with the axis C30 of the first main bearing 30 (θ does not necessarily have to be 45 °).

  On the other hand, the first outer ring 34 of the first main bearing 30 is radially inward from the outer peripheral surface 34A parallel to the axis C30 of the first main bearing 30 and the end of the outer peripheral surface 34A on the axial external gear 14 side. Of the outer peripheral surface 34A, the end of the outer peripheral surface 34A on the side opposite to the external gear and the radially inner end of the side surface 34B are connected to the axis C30 of the first main bearing 30 at an angle θ. 34C. The axis C30 of the first main bearing 30 is the same as the axis C16 of the internal gear 16 and the axis C24 of the first carrier 24.

  The first outer ring 34 has a cross section cut along a plane including the axis C30 of the first main bearing 30 (a cross section corresponding to the plane of FIG. 1 and FIG. 2) as a substantially isosceles triangle. The first outer ring 34 is provided in the casing 20 such that an outer peripheral surface 34A parallel to the axis C30 of the first main bearing 30 contacts the inner peripheral surface 20A of the casing 20.

  Note that the movement of the first outer ring 34 toward the axial external gear 14 side is restricted by a part of the side surface 34B coming into contact with the stepped portion 20G of the casing 20. A part of the side surface 34B of the first outer ring 34 is also in contact with the axial end surface 16B1 of the pin member 16B constituting the internal teeth of the internal gear 16, and restricts the axial movement of the pin member 16B. At the same time, a part of the side surface 34B of the first outer ring 34 is also in contact with the axial end surface of the external gear 14 to restrict the axial movement of the external gear 14.

  The plurality of first rollers 36 of the first main bearing 30 are constituted by cylindrical rollers (not so-called tapered rollers). That is, the outer peripheral surface 36 </ b> A of the first roller 36 of the first main bearing 30 is parallel to the rotation axis S <b> 36 of the first roller 36. The rotation axis S36 of the first roller 36 is inclined by θ (45 ° in this example) with respect to the axis C30 of the first main bearing 30. In other words, the plurality of first rollers 36 of the first main bearing 30 has a rotation axis S36 that is inclined by θ with respect to the axis C30 of the first main bearing 30. The first main bearing 30 can also be said to be a bearing having a non-zero contact angle α (= 90 ° −θ = 45 °) (α ≠ 0).

  The first retainer 38 of the first main bearing 30 includes a holding portion 38A that rotatably holds the plurality of first rollers 36, and a protruding portion 38B that protrudes from the holding portion 38A. The holding portion 38 </ b> A of the first retainer 38 is located between the first rollers 36 in the circumferential direction of the first main bearing 30, and a plurality of column portions (not shown) that position the first rollers 36 in the circumferential direction. And a pair of ring portions 38A1 and 38A2 that connect both ends of the plurality of column portions in the circumferential direction.

  The projecting portion 38B of the first retainer 38 is ring-shaped from the ring portion 38A1 of one of the pair of ring portions 38A1 and 38A2 (which has a larger diameter) toward the axially opposite external gear of the first carrier 24. It protrudes.

  The outer periphery 38B1 and the inner periphery 38B2 of the protrusion 38B protruding in a ring shape are parallel to the axis C24 of the first carrier 24. An abutting surface 38P configured by a surface perpendicular to the axis C24 of the first carrier 24 is formed at the tip of the protruding portion 38B.

  As described above, the first retaining ring 40 is disposed on the first carrier 24. Specifically, a retaining ring arrangement portion 24 </ b> K extends in parallel with the axial center C <b> 24 of the first carrier 24 on the axially opposite external gear side of the inner ring rolling surface 32 </ b> C of the first carrier 24. A retaining ring groove 24M for fitting the first retaining ring 40 is formed in the retaining ring disposing portion 24K, and the first retaining ring 40 is fitted in the retaining ring groove 24M.

  The first retainer 38 of the first main bearing 30 is in direct contact with the contacted surface (the portion that contacts the first retainer 38) 40P of the first retaining ring 40 at the contact surface 38P of the protrusion 38B. . In this example, the abutted surface 40P corresponds to the end surface of the first retaining ring 40 on the axial first main bearing 30 side.

  A contact surface (a member that contacts the first retainer 38) 40P of the first retaining ring 40 is provided with a low friction coating (not shown). That is, the abutted surface (portion that abuts against the first retainer 38) 40P of the first retaining ring 40 has a low friction coating. Specifically, the first retaining ring 40 of this embodiment is provided with a low-friction coating on the entire surface including a portion that does not contact the first retainer 38. It may be advantageous in terms of cost to apply the low friction coating to the whole. In this case, a low friction coating may be applied not only to the abutted surface 40P of the first retainer 38 but also to the entire first retaining ring 40.

  For example, the low-friction coating is a Parker treatment (chemical conversion treatment that chemically forms a phosphate coating on the surface of the first retaining ring 40 using a phosphate solution such as iron phosphate, zinc phosphate, manganese phosphate, etc. ) Or the like. In this configuration example, a manganese phosphate coating is employed as the low friction coating.

  The axial width W24M of the retaining ring groove 24M is slightly larger (by δ24M in this example) than the axial width W40 of the first retaining ring 40. For this reason, the first retaining ring 40 can be easily mounted in the retaining ring groove 24M.

  In this case, a plurality of first retaining rings 40 are prepared in which the axial width W40 of the first retaining ring 40 is slightly different (in other words, the difference δ24M from the axial width W24M of the retaining ring groove 24M is slightly different). When actually assembled, the contact surface 38P of the protrusion 38B of the first retainer 38 and the contact surface 40P of the first retaining ring 40 have an appropriate (slight) gap, or You may make it select the 1st retaining ring 40 which can contact | abut with an appropriate contact pressure. In other words, the first retaining ring 40 itself may have a function as a shim that absorbs assembly errors.

  An oil seal 64 is disposed between the casing 20 and the second carrier 124 on the load side. Therefore, the retaining ring arrangement portion 124K of the load-side second carrier 124 is formed wider than the retaining ring arrangement portion 24K of the anti-load side first carrier 24 by the amount of the oil seal 64.

  Next, the operation of the gear device 12 will be described.

  When the input gear 50 incorporated in the input shaft (not shown) rotates, the crankshaft gear 46 meshing with the input gear 50 rotates, and each crankshaft 42 rotates. Thereby, the eccentric part 44 formed in each crankshaft 42 rotates at the same rotational speed in the same direction. When the eccentric portion 44 rotates, the external gear 14 eccentrically swings via the eccentric portion bearing 52. The external gear 14 is in mesh with the internal gear 16, and the number of teeth of the internal gear 16 (the number of pin members 16 </ b> B) is one more than the number of teeth of the external gear 14. Therefore, every time the external gear 14 swings once, the external gear 14 rotates (rotates) relative to the internal gear 16 by one tooth.

  Due to the rotation of the external gear 14, the crankshaft 42 revolves around the axis C <b> 16 of the internal gear 16, and this revolution is transmitted to the first and second carriers 24 and 124. As a result, the first and second carriers 24 and 124 rotate with respect to the casing 20 via the first and second main bearings 30 and 130, and the second carrier with respect to the first arm connected to the casing 20. The second arm connected to 124 can be rotated.

  The rotation of the first and second carriers 24 and 124 relative to the casing 20 is only relative. For example, in this embodiment, the gear device 12 is applied to the joint of the robot, but when viewed from the second carrier 124 side to which the second arm is connected, the casing 20 to which the first arm is connected. Can be regarded as a rotating member.

  Here, the operation of the first and second main bearings 30 and 130 disposed between the casing 20 and the first and second carriers 24 and 124 will be described in detail.

  The plurality of first rollers 36 of the first main bearing 30 on the non-load side have a rotation axis S 36 that is inclined with respect to the axis C 30 of the first main bearing 30. Similarly, the plurality of second rollers 136 of the second main bearing 130 on the load side also have a rotation axis S136 inclined with respect to the axis C130 of the second main bearing 130.

  The first main bearing 30 and the second main bearing 130 are arranged between the casing 20 and the first carrier 24 and between the casing 20 and the second carrier 124 in a back-to-back assembling manner. Therefore, the first main bearing 30 and the second main bearing 130 can support both the radial load and the thrust load applied to the first carrier 24 and the second carrier 124 with a large working span.

  Since the plurality of first rollers 36 of the first main bearing 30 and the plurality of second rollers 136 of the second main bearing 130 perform basically the same operation, the following operations are mainly performed on the first main bearing 30 side. Focus on the explanation.

  The first roller 36 of the first main bearing 30 is a simple “cylindrical roller” having an outer peripheral surface 36A parallel to the rotation axis S36. For this reason, compared with the 1st main bearing comprised, for example with a "taper roller", when the 1st roller 36 rotates, the component force which this 1st roller 36 tends to move to rotation-axis S36 direction does not generate | occur | produce easily. .

  On the other hand, since the first retainer 38 is formed in a substantially truncated cone shape as a whole, it is difficult to move in the direction of the rotation axis S36 of the first roller 36. Therefore, a rib that restricts the movement of the first roller 36 in the direction of the rotation axis S36 on the inner ring rolling surface (outer circumferential surface) 32C of the first inner ring 32 and the outer ring rolling surface (inner circumferential surface) 34C of the first outer ring 34. Although the plurality of first rollers 36 are supported by the first retainer 38, the movement of each first roller 36 in the direction of the rotation axis S36 and the movement in the circumferential direction are basically Can be almost regulated.

  However, in reality (if the entire movement of the first retainer 38 is incorporated without any restriction), it changes every moment with a minute manufacturing error of each member and the oscillation of the external gear 14. The first retainer 38 may slightly move or twist due to fluctuations in the support load. According to the inventor's confirmation, the first retainer 38 tends to move particularly toward the large diameter side (axially anti-external gear side).

  In the gear device 12, the first retaining ring 40 is disposed on the first carrier 24, and the protrusion 38 </ b> B of the first retainer 38 contacts the abutting surface 40 </ b> P of the first retaining ring 40 at the abutting surface 38 </ b> P. It touches. Therefore, the axial movement of the first retainer 38 (the axial movement of the first carrier 24 or the movement of the first roller 36 in the direction of the rotation axis S36) can be effectively suppressed. And since the movement of the whole 1st retainer 38 is restrained more reliably, the some 1st roller 36 currently hold | maintained by this 1st retainer 38 can be hold | maintained more stably.

  In addition, since the first inner ring 32 and the first outer ring 34 are not provided with ribs that restrict the movement of the first roller 36 in the direction of the rotation axis S36, the first main bearing 30 can be manufactured at low cost. .

  In the gear device 12, when restraining the movement of the first retainer 38, the contact surface 38 </ b> P of the protrusion 38 </ b> B of the first retainer 38 is contacted with the first retaining ring 40 disposed on the first carrier 24. It is made to contact | abut directly on the surface 40P.

  The first retaining ring 40 can be manufactured at low cost (or can be obtained at low cost from many commercially available products), and the contact surface 40P of the first retaining ring 40 is It basically has smoothness and hardness capable of positioning a sliding member.

  Further, the formation of the retaining ring groove 24M is sufficient only to form a narrow groove enough for the first retaining ring 40 to enter, and high accuracy is not required for processing accuracy. Therefore, for example, a conventional groove that is “wide enough to fit a part of the retainer and high enough to withstand the sliding of the retainer (smooth machining surface) is formed in a casing or Compared with the “configuration directly formed on the carrier”, the cost can be greatly reduced.

  Further, in the gear device 12, a contacted surface (a portion that contacts the first retainer 38) 40P (more specifically, a part of the first retaining ring 40 (which is a member that contacts the first retainer 38). A low friction coating is applied to the entire first retaining ring 40 including the abutted surface 40P. Therefore, the first retaining ring 40 and the first retainer 38 can be slid more smoothly, the sliding resistance can be reduced, and the first retainer 38 can be positioned more stably.

  In this case, for example, compared with the case where the low friction coating is applied to the wide groove formed directly on the casing 20 or the first carrier 24, the gear device 12 only applies the low friction coating to the first retaining ring 40. In this respect, the low friction coating can be applied more easily and at a lower cost.

  In the above embodiment, the first retainer 38 is directly brought into contact with the first retaining ring 40 disposed on the first carrier 24. However, the first retainer 38 may not necessarily be in direct contact with the first retaining ring 40. An example of this is shown in FIG.

  In the configuration example according to FIG. 3, the first retainer 38 is in contact with the first spacer 70 (not directly in contact with the first retaining ring 40). The first spacer 70 has a predetermined width W70 in the axial direction of the first carrier 24, and is integrated with the first retaining ring 40 so as to overlap in the axial direction. The first spacer 70 is fitted on the outer periphery of the first carrier 24 with a gap fit. Although not shown, a second spacer can be similarly disposed on the second main bearing 130 side.

  As described above, when the first spacer 70 is interposed between the first retaining ring 40 and the first retainer 38, a plurality of first spacers 70 having slightly different axial widths W70 are prepared. By selecting the first spacer 70, it is possible to obtain an advantage that the assembly with the optimum axial dimension can be realized more easily. This shim function can be employed even when only the first retaining ring 40 is provided, as described above, but the dimensional adjustment is more flexible by the first spacer 70 than by the first retaining ring 40. High nature.

  In other words, the “first spacer 70 interposed between the first retaining ring 40 and the first retainer 38” herein includes the concept of shims. The number of the first spacers 70 is not necessarily one. For example, in addition to the first spacers 70, a dedicated shim may be separately prepared.

  In this example, a low friction coating is applied to the contacted surface (the portion that contacts the first retainer 38) 70P of the first spacer 70. That is, in the case where the first spacer 70 is interposed between the first retaining ring 40 and the first retainer 38 in this way (a member of the first retaining ring 40 and the first spacer 70 that contacts the first retainer 38. The low-friction film may be applied to the abutted surface 70P of the first spacer 70 (in this case, the low-friction film may be applied to the entire first spacer 70).

  When the first spacer 70 is provided with a low friction coating, the first spacer 70 made of a dedicated material can be applied with a low friction coating that is compatible with the dedicated material. There is a possibility that a more effective merit can be obtained. In this respect, the design flexibility is higher than the structure of the first retaining ring 40 alone.

  Since other configurations are the same as those of the previous embodiment, the same reference numerals are given to portions having the same or the same functions in the drawings, and redundant description is omitted. In the following modifications, similarly, the same reference numerals are given to portions having the same or the same function in the drawings, and the duplicate description is omitted.

  FIG. 4 shows a modification of FIG.

  In this modification, the first spacer 75 interposed between the first retaining ring 40 and the first retainer 38 is an L-shaped ring-shaped section cut along a plane including the axis C24 of the first carrier 24. It is comprised by the member of.

  Specifically, the first spacer 75 includes a main body portion 75A having a predetermined width W75 in the axial direction of the first carrier 24, and an axial first roller 36 of the first carrier 24 from the outer peripheral end portion of the main body portion 75A. And a protruding portion 75B protruding to the side.

  The projecting portion 38B of the first retainer 38 abuts on the axial contact surface 75P of the main body 75A of the first spacer 75 in the axial direction of the first carrier 24, and is first in the radial direction of the first carrier 24. The spacer 75 is in contact with the radial contact surface 75Q of the protrusion 75B. As a result, the first retainer 38 not only supports the reaction force when moving toward the axially anti-external gear via the first spacer 75 but also supports the reaction force when moving radially outward. The plurality of first rollers 36 can be held in a more stable state.

  By the way, as described above, the other (smaller diameter) ring part 38A2 side of the pair of ring parts 38A1 and 38A2 connecting both ends of the plurality of column parts of the holding part 38A of the first retainer 38 is As shown in the configuration examples thus far, support is not always necessary.

  However, in the configuration example of FIG. 5, the other ring part 38A2 of the pair of ring parts 38A1 and 38A2 is also formed with a protruding part 38C radially inward, and its tip surface (contact surface) 38P2 is For example, the first carrier 24 is in contact with the inner ring rolling surface 32C and the outer peripheral surface 24P adjacent to the axial external gear side. Thereby, the first retainer 38 can be supported in a more stable state.

  When the first inner ring 32 of the first main bearing 30 is independent from the first carrier 24, the protruding portion 38C of the first retainer 38 may be brought into contact with the first inner ring 32. Further, in the configuration example of FIG. 5, the protruding portion 38 </ b> C is formed facing radially inward, but the protruding portion 38 </ b> C is formed facing the axial external gear 14, and the protruding portion 38 </ b> C is axially outside. The end surface on the tooth gear 14 side may be brought into contact with the axial end surface 14E of the external gear 14.

  The contact with the first carrier 24 and the external gear 14 is not required to form a groove or the like in the first carrier 24 or the external gear 14, so only the shape of the first retainer 38 is changed. can do. Therefore, it can be implemented with little additional cost compared to the previous configuration example.

  Further, in the configuration examples so far, the first retaining ring 40 is arranged on the first carrier 24. However, the first retaining ring is not necessarily arranged on the first carrier, and may be arranged on the casing. An example of this configuration is shown in FIG.

  In the configuration example of FIG. 6, the casing 80 is greatly extended to the axially anti-external gear side of the first main bearing 30 as compared with the casing 20 of the previous embodiment. A first retaining ring 84 is arranged by forming a retaining ring groove 80M on the circumference 80B.

  The first retainer 38 is in contact with the first spacer 86 (not directly in contact with the first retaining ring 84). The first spacer 86 is embedded in the axial direction with the first retaining ring 84, and protrudes from the radially inner end of the main body 86A toward the first roller 36 in the axial direction of the first carrier 24. Projecting portion 86B. A low-friction coating is applied to a contacted surface (a portion that contacts the first retainer 38) 86P of the first spacer 86 (a member that contacts the first retainer 38). The first spacer 86 also has a low friction coating not only on the abutted surface 86P but also on the entire first spacer 86. The protrusion 38 </ b> B of the first retainer 38 is in contact with the main body 86 </ b> A of the first spacer 86 in the axial direction of the first carrier 24 and is in contact with the protrusion 86 </ b> B in the radial direction of the first carrier 24.

  Thereby, the first retainer 38 not only supports the reaction force when moving toward the axially anti-external gear via the first spacer 86 but also supports the reaction force when moving in the radial direction. We can receive power.

  In addition, in the said embodiment, although the some roller of the bearing was comprised by the cylindrical roller, the roller which concerns on the bearing of this invention is not limited to a cylindrical roller. For example, a tapered roller may be used. That is, the bearing of the present invention may be a tapered roller bearing, and even in this case, the same effects as those already described can be obtained.

  In the above embodiment, the present invention is applied to an eccentric oscillating gear device in which a plurality of crankshafts that oscillate external gears (oscillating gears) are offset from the axis of the internal gear. An example was shown. However, as an eccentric oscillating gear device, an eccentric oscillating gear device in which only one crankshaft for oscillating the external gear is provided at the axial center position of the internal gear is also known. The present invention can be similarly applied to such an eccentric oscillating gear device.

  Further, the swinging and non-swinging are relative, and as the eccentric swinging gear device, a gear device in which the internal gear swings with respect to the external gear is also known. The present invention can be similarly applied to such an eccentric oscillating gear device.

  Furthermore, the application target of the present invention is not necessarily limited to such an eccentric oscillating gear device, and can be applied to, for example, a simple planetary gear device. In short, a gear device including a casing, a carrier that rotates relative to the casing, and a bearing disposed between the casing and the carrier can be similarly applied.

DESCRIPTION OF SYMBOLS 12 ... Gear apparatus 20 ... Casing 24 ... 1st carrier 30 ... 1st main bearing C30 ... Shaft center of the main bearing 32 ... 1st inner ring 34 ... 1st outer ring 36 ... 1st roller S36 ... Roller rotating shaft 38 ... 1st Retainer 40 ... first retaining ring 70 ... first spacer

Claims (3)

In a gear device comprising a casing, a carrier that rotates relative to the casing, and a bearing disposed between the casing and the carrier,
The bearing includes an inner ring provided in the carrier, an outer ring provided in the casing, a plurality of rollers disposed between the inner ring and the outer ring, and a retainer that holds the plurality of rollers.
The plurality of rollers have a rotating shaft inclined with respect to an axis of the bearing,
On the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring are not provided with ribs that restrict the movement of the rollers in the rotational axis direction,
A retaining ring is disposed on the casing or the carrier,
The retainer is in direct contact with the retaining ring or in contact with the retaining ring through a spacer. In claim 1,
The retainer is in contact with the retaining ring via the spacer,
The spacer includes a main body portion having a predetermined width in the axial direction of the carrier, and a protruding portion protruding from the main body portion in the axial direction of the carrier,
The retainer is in contact with the main body portion in the axial direction of the carrier, and is in contact with the protruding portion in the radial direction of the carrier. In claim 1 or 2,
Of the retaining ring and the spacer, the member that abuts on the retainer has a low friction coating on a portion that abuts on the retainer.

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