JP2018035897A - Hypocycloid gear reduction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hypocycloid gear reduction device that can restrain generation of vibration and noise, and has excellent transmission efficiency of a rotating force.SOLUTION: A hypocycloid gear reduction device comprises: an input shaft 1, an output shaft 2 provided coaxially with the input shaft; a pair of eccentric shaft parts provided in the input shaft; a pair of planet gears externally fitted to the respective eccentric shaft parts via bearings; and an internal gear 9 engaged with the pair of planet gears. The output shaft and the internal gear are integrated. A first rotation regulation mechanism M1 that regulates rotation of a first planet gear arranged on the input side is provided, and a second rotation regulation mechanism M2 that regulates rotation of a second planet gear arranged on the output side is provided.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hypocycloid gear reduction device.

  The hypocycloid gear reduction gear is a gear that has a slightly different number of teeth and an external gear meshed inward and outward so that one of them swings around the other, so that a large reduction ratio can be obtained. Are proposed in various configurations (Patent Documents 1 to 3, etc.).

  The speed reducer shown in Patent Document 1 includes an input shaft that is pivotally supported by a pair of bearings, and a planetary gear block that is externally fitted to the eccentric shaft portion of the input shaft via the pair of bearings. . The planetary gear block has a pair of planetary gears, one planetary gear meshes with a fixed gear provided in the housing, and the other planetary gear meshes with an internal gear integrally provided on the output shaft. To do.

  The speed reducer shown in Patent Document 2 is provided with gears meshing inward and outward with different numbers of teeth on an eccentric portion of an input shaft and an output shaft disposed coaxially with the input shaft. In this case, the input shaft side gear provided at the eccentric portion of the input shaft is swung around the output shaft side gear provided at the output shaft, and the rotation of the swiveling input shaft side gear is engaged with the fixed portion. Means to stop when there is a failure is provided.

  The speed reducer shown in Patent Document 3 has a hard sphere interposed between an end surface of a boss portion provided on a planetary gear and an end surface of an output shaft. That is, a recess is provided on the end face of the output shaft, and a hard sphere incorporated in the end face of the boss part is fitted into the recess. In this case, the hard sphere moves circularly while rolling on the bottom of the recess with the same radius as the revolution of the planetary gear, and the rotation output decelerated by the rotation of the planetary gear is transmitted to the output shaft.

Japanese Utility Model Publication No. 1-131049 JP 2007-10047 A JP-A-6-33995

  In the thing of patent document 1, input torque will be input from the eccentric shaft part of an input shaft. However, since the position of the center of gravity of the input shaft with a high rotational speed is eccentric, vibration and noise are likely to occur, and there is a possibility that a high-quality speed reducer cannot be provided. Further, since the rotation of the input shaft is transmitted to the output shaft only by meshing the gears, the meshing efficiency decreases as the reduction ratio is set higher, and the overall efficiency decreases.

  In the case described in Patent Document 2, as in the case described in Patent Document 1, the position of the center of gravity of the input shaft having a high rotational speed is eccentric, and vibration and noise are likely to occur. There is a risk that high-quality gearheads cannot be provided. In addition, since the internal gear with which the planetary gear meshes is provided on the input shaft side, there is a drawback that the shape of the internal gear becomes complicated.

  In the thing of patent document 3, the recessed part is provided in the output-shaft end surface, and the hard sphere built in the end surface of the boss | hub part is fitted in this recessed part. For this reason, the hard sphere fixed by the concave portion having substantially the same diameter as the hard sphere slides on the bottom of the concave portion of the output shaft end face, and there is a problem that the transmission efficiency of the rotational force is poor.

  Therefore, the present invention provides a hypocycloid gear reduction device that can suppress generation of vibration and noise and is excellent in rotational force transmission efficiency.

  A first hypocycloid gear reduction device of the present invention includes an output shaft, an input shaft disposed coaxially with the output shaft, a pair of eccentric shaft portions provided on the input shaft, and each eccentric shaft. A hypocycloid gear transmission comprising a pair of planetary gears externally fitted to a part via a bearing, and an internal gear meshing with the pair of planetary gears, wherein the output shaft and the internal gear are integrated; A second planetary gear is provided on the output side between the first planetary gear and the output planetary gear while providing a first rotation restricting structure for restricting the rotation of the first planetary gear arranged on the input side. Is provided with a second rotation restricting structure for restricting the rotation.

According to the hypocycloid gear reduction device of the present invention, the rotation of the first planetary gear can be restricted by the first rotation restriction structure, and the rotation of the second planetary gear is restricted by the second rotation restriction structure. Therefore, the planetary gear can revolve efficiently. For this reason, if the input shaft rotates about its axis, the internal gear meshing with the pair of planetary gears rotates about its axis. When the internal gear rotates, the output shaft integrated with the internal gear rotates.
In addition, since the input shaft is provided with a pair of eccentric shaft portions, the load balance is improved.

  The first rotation restricting structure includes an annular gear-side raceway groove provided at a predetermined pitch along a circumferential direction on a fixed portion facing surface of the first planetary gear, and a first portion of the fixed portion facing the first planetary gear. A plurality of annular fixed portion side raceway grooves provided at a predetermined pitch along the circumferential direction on one planetary gear facing surface, and a rolling element interposed between the gear side raceway groove and the fixed portion side raceway groove facing the same. And the center of the ring of the gear-side raceway groove and the center of the ring of the fixed-side raceway groove are decentered, and the second rotation restricting structure is provided circumferentially on the second gear-facing surface of the first planetary gear. A plurality of annular first planetary gear side raceway grooves provided at a predetermined pitch along the first planetary gear side raceway groove and a second planetary gear side annular groove provided at a predetermined pitch along the circumferential direction on the first planetary gear facing surface of the second planetary gear. 2 planetary gear side raceway grooves, first planetary gear side raceway grooves and a second planetary gear opposite thereto Together and a rolling element interposed between the raceway grooves can be configured in which the annular center of the circular ring around the second planetary gear side raceway groove of the first planetary gear raceway groove was eccentric.

  In the first rotation restricting structure, the rolling element fitted between the gear side raceway groove and the fixed part side raceway groove is eccentrically opposed by the eccentric motion of the first planetary gear. Rolls at different positions. For this reason, rotation of the 1st planetary gear swung around can be prevented by the rolling engagement of the raceway groove and the rolling element. Further, in the second rotation restricting structure, the rolling element fitted between the first planetary gear side raceway groove and the second planetary gear side raceway groove is offset by the eccentric motion of the second planetary gear side. Rolls at positions shifted from each other in the raceway grooves facing each other. For this reason, the rotation of the second planetary gear rotating around can be prevented by the rolling engagement between the raceway groove and the rolling element.

  It is preferable that the eccentric shaft center of the first planetary gear and the eccentric shaft center of the second planetary gear are arranged at positions opposite to each other by 180 ° with respect to the axis of the input shaft. By setting in this way, the load balance is further stabilized.

  The first planetary gear and the second planetary gear are preferably used as common parts. By setting in this way, the weight balance is improved.

  The second hypocycloid gear reduction device of the present invention includes an output shaft, an input shaft disposed coaxially with the output shaft, an eccentric shaft portion provided on the input shaft, and a bearing on the eccentric shaft portion. A hypocycloid gear transmission comprising a planetary gear externally fitted via an internal gear and an internal gear meshing with the planetary gear, wherein the output shaft and the internal gear are integrated with each other. A balancer that balances rotation is provided, and a rotation restricting structure that restricts the rotation of the planetary gear is provided.

  Since the rotation of the planetary gear can be restricted by the rotation restriction structure, the planetary gear can efficiently revolve. For this reason, if the input shaft rotates about its axis, the internal gear meshing with the planetary gear rotates about its axis. When the internal gear rotates, the output shaft integrated with the internal gear rotates. In addition, since the balancer is provided, the load balance is improved.

  The rotation restricting structure includes a ring-shaped gear-side raceway groove that is provided in a predetermined pitch along the circumferential direction on the fixed portion facing surface of the planetary gear, and a planetary gear facing surface of the fixed portion that faces the planetary gear in the circumferential direction. A plurality of annular fixed part side raceway grooves provided at a predetermined pitch along the gear side raceway grooves, and rolling elements interposed between the gear side raceway grooves and the fixed part side raceway grooves opposed thereto. It is preferable to decenter the center of the ring and the center of the ring of the fixed part side raceway groove.

  By setting in this way, the rolling elements fitted between the gear-side raceway groove and the fixed part-side raceway groove are caused by the eccentric movement of the planetary gears so that the eccentrically opposed raceway grooves are mutually opposed. Roll over the shifted position. For this reason, rotation of the planetary gear swung around can be prevented by the rolling engagement between the raceway groove and the rolling element.

  In the present invention, the planetary gear can revolve efficiently and the load balance is improved. Therefore, it is possible to provide a hypocycloid gear reduction device that can suppress generation of vibration and noise and that is excellent in rotational force transmission efficiency.

It is sectional drawing which shows 1st Embodiment of the hypocycloid gear reduction device of this invention. It is a perspective view shown with a partial cross section of the hypocycloid gear reduction device shown in FIG. The hypocycloid gear reduction device shown in FIG. 1 is shown, (a) is a perspective view, and (b) is a side view. It is a front view of the planetary gear assembly of the state with which the input shaft was mounted | worn via the bearing. FIG. 5 is a sectional view taken along line A in FIG. 4. It is a perspective view of the 1st planetary gear. It is a front view of a planetary gear assembly. It is the BB sectional view taken on the line of FIG. It is a principal part expanded sectional view of a planetary gear assembly. It is sectional drawing which shows 2nd Embodiment of the hypocycloid gear speed reducer of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3 show a hypocycloid gear reduction device (hereinafter sometimes simply referred to as a gear reduction device). This gear reduction device includes an input shaft 1 connected to a drive source (not shown) and an input. An output shaft 2 disposed coaxially with the shaft 1, a pair of eccentric shaft portions 3, 4 provided on the input shaft 1, and outer shaft shafts 3, 4 via bearings 5, 6. A pair of planetary gears 7 and 8 to be fitted and an internal gear 9 meshing with the pair of planetary gears 7 and 8 are provided.

  The input shaft 1 is formed between the shaft end portions 1a and 1b at both ends, the pair of eccentric shaft portions 3 and 4 provided between the shaft end portions 1a and 1b, and the eccentric shaft portions 3 and 4. It consists of the central large diameter part 10. The shaft centers (eccentric shaft centers O1 and O2) of the eccentric shaft portions 3 and 4 are shifted by a predetermined dimension on the opposite side from the axis (center) of the input shaft 1 by 180 degrees. In this case, the eccentric amounts of the eccentric shaft portions 3 and 4 are the same. The eccentric amount of one eccentric shaft portion (one shaft end portion 1a side, that is, the eccentric shaft portion on the input side) 3 is L1, and the other eccentric shaft portion (one shaft end portion 1b side, that is, the output). L1 = L2 when the eccentric amount of the eccentric shaft portion 4 on the side is L2.

  The outer diameter dimension of the one eccentric shaft portion 3 and the outer diameter dimension of the other eccentric shaft portion 4 are set to be the same. That is, when the outer diameter of the eccentric shaft portion 3 is D1 and the outer diameter of the eccentric shaft portion 4 is D2, D1 = D2. The central axis of the central large-diameter portion 10 is disposed on the input shaft O, and the outer diameter surface 10a is closer to the outer diameter side than the outer diameter surface of the eccentric shaft portion 3 and the outer diameter surface of the eccentric shaft portion 4. Arranged.

  For this reason, a stepped portion 11 is formed between the outer diameter surface 3a of the eccentric shaft portion 3 and the outer diameter surface 10a of the central large diameter portion 10, and the outer diameter surface 4a of the eccentric shaft portion 4 and the center A stepped portion 12 is formed between the outer diameter surface 10 a of the large diameter portion 10. One eccentric shaft portion 3 may be referred to as a first eccentric shaft portion 3, and the other eccentric shaft portion 4 may be referred to as a second eccentric shaft portion 4.

  The bearings 5 and 6 include an inner ring 5a, 6a having a raceway surface formed on an outer diameter surface, an outer ring 5b, 6b having a raceway surface formed on an inner diameter surface, and the inner rings 5a, 6a and the outer rings 5b, 6b. Rolling elements (balls) 5c and 6c are provided so as to be freely rollable. The bearing 5 has an inner ring 5 a fitted on the first eccentric shaft portion 3, and the bearing 6 has an inner ring 6 a fitted on the second eccentric shaft portion 4.

  In this case, the circumferential notch 13 is formed on the shaft end 1 a side of the first eccentric shaft 3, and the spacer ring 14 is fitted into the circumferential notch 13. An inner ring 5 a of the bearing 5 is disposed between the spacer ring 14 and the stepped portion 11. Further, a circumferential notch 15 is provided on the shaft end 1 b side of the second eccentric shaft 4, and a spacer ring 16 is fitted into the circumferential notch 15. An inner ring 6 a of the bearing 6 is disposed between the spacer ring 16 and the stepped portion 12.

  As shown in FIGS. 1 and 4 to 8, the input-side planetary gear (first planetary gear) 7 is formed of a disc body having an axial hole 18, and uneven teeth 19 are provided on the outer peripheral surface thereof. Therefore, the shaft hole 18 is provided with an inner flange 20 on the output-side planetary gear (second planetary gear) 8 side, and the end surface of the outer ring 5b of the bearing 5 on the inner flange 20 side is the inner flange 20. The outer ring 5 b of the bearing 5 is fitted in the shaft hole 18 so as to abut against the shaft center hole 18. The output-side planetary gear (second planetary gear) 8 is formed of a disc body having an axial hole 21 and is provided with concave and convex teeth 22 on the outer peripheral surface thereof. For this reason, the shaft hole 21 is provided with an inner flange portion 23 on the input planetary gear (first planetary gear) 7 side, and the end surface of the outer ring 6b of the bearing 6 on the inner flange portion 23 side is the inner flange portion 23. The outer ring 6 b of the bearing 6 is fitted into the shaft hole 21 so as to abut on the shaft center hole 21.

  Incidentally, as shown in FIG. 1, the first planetary gear 7, the second planetary gear 8, and the like are housed in a case (housing) 25. The case 25 includes a first member 26 having a cylindrical body portion 26a and a lid member 26b provided in an output side opening portion of the body portion 26a, and an input side opening portion of the first member 26. And a second member 27 having a lid member 27a for closing.

  The lid member 26b is a disk-shaped body having an axial hole 30, and the axial hole 30 includes a large diameter part 30a, an intermediate diameter part 30b, and a small diameter part 30c. The output shaft 2 is pivotally supported by the shaft hole 30 via a bearing 31. The bearing 31 is provided between an inner ring 31a having a raceway surface formed on an outer diameter surface, an outer ring 31b having a raceway surface formed on an inner diameter surface, and a rolling roller disposed between the inner ring 31a and the outer ring 31b. A moving body (ball) 31c. The body portion 26a is provided with a plurality of through holes 45 at a predetermined pitch (45 ° pitch as shown in FIG. 3A) along the circumferential direction. In addition, the pitch angle of the through-hole 45 in the trunk | drum 26a is not restricted to 45 degrees, but is arbitrary.

  Further, the lid member 27 a is provided with a recessed portion 32 on the end surface on the inner surface side, and the opening end portion of the body portion 26 a of the first member 26 is fitted into the recessed portion 32. The recessed portion 32 is provided with a ring-shaped protruding portion 32a. A screw hole 33 corresponding to the through hole 45 of the body portion 26a of the first member 26 is provided in the lid member 27a. For this reason, the opening end portion of the body portion 26a of the first member 26 is fitted into the recessed portion 32 of the lid member 27a, and a bolt member (not shown) is connected to the body portion 26a of the first member 26 from the output side. When inserted through the through hole 45 and screwed into the screw hole 33 of the second member 27, the first member 26 and the second member 27 are integrated to assemble the case 25.

  The shaft end 1 a of the input shaft 1 is pivotally supported by the shaft hole 34 of the lid member 27 a via a bearing 35. The bearing 35 includes an inner ring 35a having a raceway surface formed on an outer diameter surface, an outer ring 35b having a raceway surface formed on an inner diameter surface, and a rolling element that is rotatably disposed between the inner ring 35a and the outer ring 35b. (Ball) 35c.

  In this case, an inner flange portion 34 a is provided at the input side opening of the shaft hole 34 of the lid member 27 a, and the swelling between the shaft end portion 1 a of the input shaft 1 and the first eccentric shaft portion 3 is provided. An exit 36 is provided. Therefore, the end surface of the outer ring 35b of the bearing 35 on the outside of the device abuts on the inner end surface of the inner flange portion 34a, and the end surface of the inner ring 35a of the bearing 35 on the device inner side contacts the end surface of the bulging portion 36 or the spacer ring 14. The outer ring 35 b is fitted into the shaft hole 34 of the lid member 27 a so that the inner ring 35 a comes into contact with the shaft end 1 a of the input shaft 1.

  By the way, the output shaft 2 has a boss portion 38 in which a concave portion 37 is formed on the inner side of the device, and a disk portion 39 that extends from the inner side of the boss portion 38 in the outer diameter direction is continuously provided. The concave portion 37 of the boss portion 38 has a large diameter portion 37 a and a small diameter portion 37 b, and a bulging portion 40 is provided between the shaft end portion 1 b of the input shaft 1 and the second eccentric shaft portion 4. It is done.

  Then, the bearing 41 is fitted into the recess 37 of the boss portion 38. The bearing 41 includes an inner ring 41a having a raceway surface formed on an outer diameter surface, an outer ring 41b having a raceway surface formed on an inner diameter surface, and a rolling roller disposed between the inner ring 41a and the outer ring 41b. A moving body (ball) 41c.

  For this reason, the end surface of the outer ring 41b of the bearing 41 on the apparatus outside side contacts the stepped surface 37c of the large diameter portion 37a and the small diameter portion 37b, and the end surface of the inner ring 41a of the bearing 41 on the apparatus inner side is inflated. The outer ring 41 b is fitted into the large-diameter portion 37 a of the concave portion 37 of the boss portion 38 and the inner ring 41 a is fitted onto the shaft end portion 1 b of the input shaft 1 so as to abut against the end surface or the spacer ring 16.

  The boss portion 38 has a large diameter portion 38 a, a medium diameter portion 38 b, and a small diameter portion 38 c, and a bulging portion 42 is provided between the large diameter portion 38 a and the disk portion 39. For this reason, the end surface on the inner side of the inner ring 31a of the bearing 31 is in contact with the end surface of the bulging portion 42, and the outer ring 31b of the bearing 31 is a step between the large-diameter portion 30a and the medium-diameter portion 30b of the lid member 26b. The outer ring 31 b is fitted to the large diameter part 30 a of the lid member 26 b and the inner ring 31 a is fitted to the large diameter part 38 a of the boss part 38 so as to contact the attaching part 43.

  The medium diameter portion 38b of the boss portion 38 corresponds to the medium diameter portion 30b of the axial hole 30 of the lid member 26b, and the small diameter portion 38c of the boss portion 38 corresponds to the small diameter portion 30c of the axial hole 30 of the lid member 26b. To do. At this time, the inner diameter dimension of the medium diameter part 30 b of the shaft hole 30 is larger than the outer diameter dimension of the medium diameter part 38 b of the boss part 38, and the inner diameter dimension of the small diameter part 30 c of the shaft hole 30 is the same as that of the boss part 38. The outer diameter of the small diameter portion 38c is set to be larger.

  Incidentally, an internal gear 9 that meshes with the first planetary gear 7 and the second planetary gear 8 is connected to the disk portion 39 of the output shaft 2. That is, the internal gear 9 includes a main body 51 made of a ring body and uneven teeth 52 provided on the inner peripheral surface of the main body 51. The main body 51 is provided with a plurality of screw holes 53 at a predetermined pitch along the circumferential direction. The axial center of the screw hole 53 is provided in parallel with the axial center of the main body 51. In addition, the disk portion 39 is provided with a through hole 46 on the outer periphery thereof so as to correspond to the screw hole 53. For this reason, the internal gear 9 is integrated with the output shaft 2 by fitting a bolt member (not shown) into the through hole 46 and screwing it into the screw hole 53 of the internal gear 9.

  In this device, the first rotation restricting structure M1 for restricting the rotation of the first planetary gear 7 disposed on the input side is provided, and the second rotation for restricting the rotation of the second planetary gear 8 disposed on the output side is provided. A rotation restricting structure M2 is provided.

  As shown in FIGS. 1, 2, and 4, a plurality of first rotation restricting structures M <b> 1 are provided at a predetermined pitch along the circumferential direction on the fixed portion facing surface 7 a of the first planetary gear 7 (45 in the embodiment). (Eight at a pitch) around the annular gear-side raceway groove 55 and the first planetary gear facing surface (end surface of the protruding portion 32a of the lid member 27a) 32a1 of the fixed portion facing the first planetary gear 7. An annular fixed portion side raceway groove 56, a gear side raceway groove 55, and a fixed portion side raceway groove opposed to the annular fixed portion side raceway groove 56 provided at a predetermined pitch along the direction (in this embodiment, 8 pieces at a 45 ° pitch). And rolling elements 57 interposed between the two. The annular center O5 of the gear side raceway groove 55 is eccentric with respect to the annular center O6 of the fixed part side raceway groove 56. At this time, the annular center O5 of the gear-side raceway groove 55 and the annular center O6 of the fixed portion-side raceway groove 56 are preferably eccentric in the opposite direction by 180 °. Crests 55a and 56a are formed at the center of the gear-side raceway groove 55 and the fixed part-side raceway groove 56, and the centers of the crests 55a and 56a are the ring centers O5 and O6.

  In addition, a plurality of second rotation restricting structures M2 are provided on the second gear facing surface 7b of the first planetary gear 7 at a predetermined pitch along the circumferential direction (in this embodiment, eight at a 45 ° pitch). A plurality of the first planetary gear side raceway grooves 58 and the first planetary gear facing surface 8a of the second planetary gear 8 are provided at a predetermined pitch along the circumferential direction (in this embodiment, eight at a 45 ° pitch). An annular second planetary gear side raceway groove 59, a first planetary gear side raceway groove 58, and a rolling element 60 interposed between the second planetary gear side raceway groove 59 facing the annular planetary gear side raceway groove 59 are provided. The annular center O7 of the first planetary gear side raceway groove 58 is eccentric with respect to the annular center O8 of the second planetary gearside raceway groove 59. At this time, the annular center O7 of the first planetary gear side raceway groove 58 and the annular center O8 of the second planetary gearside raceway groove 59 are preferably eccentric in the opposite direction by 180 °. In the center of the first planetary gear side raceway groove 58 and the second planetary gear side raceway groove 59, ridges 58a, 59a are formed, and the axial centers of the ridges 58a, 59a are the ring centers O7, O8.

  By the way, an annular raceway groove 54 having a peak portion 54a at the center is also formed on the output side end face of the second planetary gear 8, and this is because the first planetary gear 7, the second planetary gear 8, Is composed of the same parts. That is, when the second planetary gear 8 is used for the first planetary gear 7, the raceway groove 54 becomes the gear side raceway groove 55 of the first rotation restricting structure M1. In FIG. 2, the raceway groove 54 is omitted.

  Next, the operation of the gear reduction device configured as described above will be described. When a rotational driving force is input to the input shaft 1 from a drive source (not shown), the input shaft 1 rotates about its axis. And since the pair of planetary gears 7 and 8 fitted on the pair of eccentric shaft portions 3 and 4 provided on the input shaft 1 via the bearings 5 and 6 mesh with the internal gear 9, the internal gear 9 will swing around while meshing. At this time, in the first rotation restricting structure M1, the rolling element 57 fitted between the gear side raceway groove 55 and the fixed portion side raceway groove 56 is accompanied by the eccentric motion of the first planetary gear 7. It rolls in the position where the eccentric grooves 50 and 56 which are opposed to each other deviate from each other. For this reason, the rolling engagement of the raceway grooves 55 and 56 and the rolling element 57 can prevent the first planetary gear 7 that rotates around from rotating.

  In the second rotation restricting structure M2, the rolling element 60 fitted between the first planetary gear side raceway groove 58 and the second planetary gear side raceway groove 59 has the eccentric motion of the second planetary gear 4. As a result, the positions of the eccentric and opposed raceway grooves 58 and 59 that are offset from each other roll. For this reason, the rotation of the second planetary gear 8 swung around can be prevented by the rolling engagement between the raceway grooves 58 and 59 and the rolling element 60.

  Therefore, the internal gear 9 rotates about its axis, and the output shaft 2 integrated with the internal gear 9 rotates about its axis.

  For this reason, the planetary gears 7 and 8 can revolve efficiently, and the load balance is improved. Therefore, it is possible to provide a hypocycloidal gear device that can efficiently obtain a large reduction ratio and that is excellent in rotational force transmission efficiency. Furthermore, it is possible to provide a hypocycloid gear reduction device that can suppress generation of vibration and noise, and is quiet and excellent in durability. In addition, since the input shaft 1 is provided with the pair of eccentric shaft portions 3 and 4, the load balance is improved.

  Next, FIG. 10 shows another embodiment, and in this hypocycloid gear reduction device, the input shaft has one eccentric shaft portion 72 (eccentric axis O4). The planetary gear used for the reduction gear is one planetary gear 73. The input shaft 1 includes an input-side shaft main body portion 61 and an output-side shaft end portion 62, an intermediate diameter portion 63 between the shaft main body portion 61 and the shaft end portion 62, an intermediate diameter portion 63, and a shaft main body portion. 61 and a collar portion 64 between them. Then, the eccentric shaft portion 72 is formed by fitting the spacer 71 to the medium diameter portion 63.

  A planetary gear 73 is externally fitted to the eccentric shaft portion 72 via a bearing 65. The bearing 65 includes an inner ring 65a having a raceway surface formed on an outer diameter surface, an outer ring 65b having a raceway surface formed on an inner diameter surface, and a rolling element that is rotatably disposed between the inner ring 65a and the outer ring 65b. (Ball) 65c. A flat ring body 66 is externally fitted to the collar portion 64.

  For this reason, the end face on the flat plate ring body 66 side of the inner ring 65 a of the bearing 65 and the end face on the flat plate ring body 66 side of the spacer 71 of the eccentric shaft part 72 are in contact with the flat plate ring body 66. The inner ring 65 a of the bearing 65 is fitted on the portion 72. Further, the planetary gear 73 is formed of a disc body having an axial hole 68 as in the first planetary gear 7, and is provided with uneven teeth 69 on the outer peripheral surface thereof. Therefore, the shaft hole 68 is provided with an inner flange portion 70 on the input side, and the outer ring of the bearing 65 is arranged such that the end surface of the outer ring 65b of the bearing 65 on the inner flange portion 70 abuts the inner flange portion 70. 65 b is fitted into the axial hole 68.

  Further, a balancer 75 that balances rotation with the planetary gear 73 is provided on the output side of the medium diameter portion 63. That is, the balancer 75 includes a disc-shaped main body portion 75a that is externally fitted and fixed to the output side of the medium diameter portion 63, and a weight portion 75b that is connected to the main body portion 75a. For this reason, it is possible to balance rotation with the planetary gear 73. The balancer 75 is interposed between the inner ring 65 a to the spacer 71 of the bearing 65 and the ring body 74 fitted to the output side of the shaft end portion 62 of the input shaft 1. Further, the weight portion 75 b does not contact the spacer 71, the bearing 65, and the planetary gear 73, and the balancer 75 does not contact the bearing 41, the disk portion 39 of the output shaft 2, and the internal gear 9.

  The output shaft 2 in this case has a boss portion 38 having a recess 37 formed on the inner side of the device, like the output shaft 2 of FIG. 1, and a disk extending from the inner side of the boss portion 38 in the outer diameter direction. The part 39 is continuously provided. The concave portion 37 of the boss portion 38 has a large diameter portion 37a and a small diameter portion 37b. The boss portion 38 in this case has a large-diameter portion 38a and a medium-diameter portion 38b, and further includes an output shaft main body 77 provided continuously from the medium-diameter portion 38b via a base portion 76.

  The output shaft 2 is also pivotally supported by the lid member 26b of the case 25 via a bearing 31 that is externally fitted to the large diameter portion 38a of the boss portion 38, like the output shaft 2 of FIG. In the first member 26 of the case 25, the axial hole 30 of the lid member 26b has a large-diameter portion 30a, a medium-diameter portion 30b, and a small-diameter portion 30c, and is formed in the opening on the output side of the small-diameter portion 30c. A collar 30d is provided. For this reason, the bearing 31 that is externally fitted to the large-diameter portion 38a of the boss portion 38 is internally fitted to the large-diameter portion 30a of the lid member 26b. Further, the medium diameter portion 38b of the boss portion 38 corresponds to the medium diameter portion 30b of the axial hole 30 of the lid member 26b, and the base portion 76 of the output shaft 2 corresponds to the small diameter portion 30c of the axial hole 30 of the lid member 26b. Correspondingly, the connecting portion of the base portion 76 of the output shaft 2 and the output shaft main body 77 corresponds to the inner flange portion 30d of the lid member 26b. 10 is the same as that of the first member 26 of the case 25 shown in FIG. 1, and the same reference numerals as those shown in FIG. . For this reason, the concave / convex teeth 52 of the internal gear 9 provided on the output shaft 2 mesh with the concave / convex teeth 69 of the planetary gear 73.

  Further, the shaft end 62 of the input shaft 1 is pivotally supported by the boss portion 38 of the output shaft 2 via the bearing 41, and the shaft main body 61 of the second member 27 of the case 25 is supported via the bearing 35. The lid member 27a is pivotally supported. Further, the lid member 27a of the second member 27 of the case 25 has the same configuration as the lid member 27a of the second member 27 of the case 25 in FIG.

  In this case, a rotation restricting structure M3 for restricting the rotation of the planetary gear 73 is provided. The rotation restricting structure M3 includes an annular gear-side raceway groove 80 that is provided in a predetermined pitch along the circumferential direction on the fixed portion facing surface 73a of the planetary gear 73, and a planetary gear facing of the fixed portion that faces the planetary gear 73. A plurality of annular fixed portion side raceway grooves 81 provided at a predetermined pitch along the circumferential direction on the surface (that is, the end surface of the protruding portion 32a of the lid member 27a) 32a1 and the gear side raceway groove 80 face each other. And rolling elements 82 interposed between the fixed portion side raceway grooves 81. In this case, the annular center O9 of the gear side raceway groove 80 and the annular center O10 of the fixed part side raceway groove 81 are eccentric. At this time, the annular center O9 of the gear side raceway groove 80 and the annular center O10 of the fixed part side raceway groove 81 are preferably eccentric in the opposite direction by 180 °.

  Next, the operation of the gear reduction device configured as described above will be described. When a rotational driving force is input to the input shaft 1 from a drive source (not shown), the input shaft 1 rotates about its axis. Since the planetary gear 73 that is externally fitted to the eccentric shaft portion 72 provided on the input shaft 1 via the bearing 65 meshes with the internal gear 9, it swings around while meshing with the internal gear 9. . However, at this time, since the rotation restricting structure M3 is provided, the rolling element 82 fitted between the gear side raceway groove 80 and the fixed portion side raceway groove 81 is eccentric with the movement of the planetary gear. Thus, the positions of the opposed raceway grooves that are shifted from each other roll. For this reason, the rolling engagement between the raceway groove 80 and the rolling element 82 can prevent the planetary gear 73 rotating around from rotating.

  Therefore, the internal gear 9 rotates about its axis, and the output shaft 2 integrated with the internal gear 9 rotates about its axis.

  For this reason, the planetary gear 73 can efficiently revolve, and the load balance is improved. For this reason, a large reduction gear ratio can be obtained efficiently, and a hypocycloid gear device having excellent rotational force transmission efficiency can be provided. Furthermore, it is possible to provide a hypocycloid gear reduction device that can suppress generation of vibration and noise, and is quiet and excellent in durability. In addition, since the balancer 75 is provided on the input shaft 1, the load balance is improved.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made. As a driving source for inputting a driving force to the input shaft 1, a motor is used. Or an engine. In FIG. 1, the fixed-side raceway groove 55 and the gear-side raceway groove 56 of the first rotation restricting structure M1 are directly provided on the lid member 27a and the planetary gear 7 of the case 25, respectively. The grooves 55 and 56 may be formed separately from the lid member 27a and the planetary gear 7 of the case 25, and these separate members may be fixed to the lid member 27a and the planetary gear 7 of the case 25. The same applies to the rotation restriction structure M2 and the rotation restriction structure M3 shown in FIG.

  The number of raceway grooves 55, 56, 58, 59, 80, 81 of the rotation restricting structures M1, M2, M3 is not limited to eight each, as long as the number of corresponding pitches of the grooves is the same. Is optional. The size of each rolling element (ball) 57, 60, 82 can be variously changed according to the size of each raceway groove 55, 56, 58, 59, 80, 81. Any device that can regulate rotation is acceptable.

  Moreover, in the said embodiment, although each track groove 55, 56, 58, 59, 80, 81 was each arrange | positioned on the same periphery, it does not restrict to this. Further, the rolling elements 57, 60, 82 of the respective rotation restricting structures M1, M2, M3 are not limited to balls, but are rollingly engaged with the raceway grooves 55, 56, 58, 59, 80, 81. Therefore, the cross-sectional shape of each raceway groove 55, 56, 58, 59, 80, 81 is not limited to the illustrated example. In addition, in the said embodiment, although the ball bearing was used as the bearings 5 and 6 etc., you may use other bearings, such as a cylindrical roller bearing.

  In the apparatus shown in FIG. 1, the first planetary gear 7 and the second planetary gear 8 are composed of the same member, so that the raceway groove 54 is formed also on the output side end surface of the second planetary gear 8. However, the track groove 54 may not be provided. The eccentric amounts of the first eccentric shaft portion 3 and the second eccentric shaft portion 4 can also be set arbitrarily. The gear specifications such as the number of teeth of the first planetary gear 7 and the second planetary gear 8 are set to be the same, but the gear specifications of the first planetary gear 7 and the gear specifications of the second planetary gear 8 are the same. As long as it is, the gear specifications such as the number of teeth can be arbitrarily set. The change of the gear specifications of the planetary gear is arbitrary. Here, the gear specifications are module, pressure angle, helix angle (helical angle), number of teeth, dislocation coefficient, reference pitch circle diameter, basic circle diameter, tip circle diameter, root circle diameter, backlash, overpin Dimensions, gear accuracy, shaft distance, etc.

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Output shaft 3 1st eccentric shaft part 4 2nd eccentric shaft parts 5 and 6 Bearing 7 1st planetary gear 7a Fixed part opposing surface 7b Gear opposing surface 8 Second planetary gear 8a Planetary gear opposing surface 9 Inside Gear 55 Gear-side raceway groove 56 Fixed portion-side raceway groove 57 Rolling body 58 First planetary gear-side raceway groove 59 Second planetary gear-side raceway groove 60 Rolling body 65 Bearing 72 Eccentric shaft 73 Planetary gear 75 Balancer 80 Gear-side raceway Groove 81 Fixed part side raceway groove 82 Rolling elements M1, M2, M3 Rotation restricting structure O Input shaft center O5, O6, O7, O8, O9, O10 Center of the ring

Claims (6)

An input shaft, an output shaft disposed coaxially with the input shaft, a pair of eccentric shaft portions provided on the input shaft, and a pair of planets externally fitted to the eccentric shaft portions via bearings A hypocycloid gear transmission comprising a gear and an internal gear meshing with the pair of planetary gears, wherein the output shaft and the internal gear are integrated,
A first rotation restricting structure for restricting the rotation of the first planetary gear disposed on the input side and a second rotation restricting structure for restricting the rotation of the second planetary gear disposed on the output side are provided. A hypocycloid gear transmission characterized by the above. The first rotation restricting structure includes an annular gear-side raceway groove provided at a predetermined pitch along a circumferential direction on a fixed portion facing surface of the first planetary gear, and a first portion of the fixed portion facing the first planetary gear. A plurality of annular fixed portion side raceway grooves provided at a predetermined pitch along the circumferential direction on one planetary gear facing surface, and a rolling element interposed between the gear side raceway groove and the fixed portion side raceway groove facing the same. And eccentrically center the annular center of the gear side raceway groove and the annular center of the stationary part side raceway groove,
The second rotation restricting structure includes an annular first planetary gear side raceway groove that is provided in plural at a predetermined pitch along the circumferential direction on the second gear facing surface of the first planetary gear, and the first planetary gear first gear. A plurality of annular second planetary gear side raceway grooves provided on the planetary gear facing surface at a predetermined pitch along the circumferential direction, a first planetary gear side raceway groove, and a second planetary gear side raceway groove facing the first planetary gear side raceway groove. 2. A rolling element interposed between the first planetary gear side raceway groove and the second planetary gear side raceway groove. Hypocycloid gear transmission.   3. The eccentric shaft center of the first planetary gear and the eccentric shaft center of the second planetary gear are arranged at positions opposite to each other by 180 ° with respect to the axis of the input shaft. Hypocycloid gear transmission.   The hypocycloid gear transmission according to any one of claims 1 to 3, wherein the first planetary gear and the second planetary gear are common parts. An input shaft, an output shaft disposed coaxially with the input shaft, an eccentric shaft portion provided on the input shaft, a planetary gear externally fitted to the eccentric shaft portion via a bearing, and the planetary gear A hypocycloid gear transmission comprising an internal gear meshing with a gear, wherein the output shaft and the internal gear are integrated,
A hypocycloid gear transmission comprising a balancer that balances rotation with a planetary gear on the input shaft, and a rotation regulating structure that regulates the rotation of the planetary gear.   The rotation restricting structure includes a ring-shaped gear-side raceway groove that is provided in a predetermined pitch along the circumferential direction on the fixed portion facing surface of the planetary gear, and a planetary gear facing surface of the fixed portion that faces the planetary gear in the circumferential direction. A plurality of annular fixed part side raceway grooves provided at a predetermined pitch along the gear side raceway grooves, and rolling elements interposed between the gear side raceway grooves and the fixed part side raceway grooves opposed thereto. The hypocycloid gear transmission according to claim 5, wherein the center of the ring and the center of the ring of the fixed part side raceway groove are eccentric.

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