TW201537066A - Gear power transmission device - Google Patents

Abstract

A gear power transmission device is configured in such a manner that a carrier is supported by a case through a bearing. The bearing is provided with an inner race, an outer race, rollers, and a retainer. The rotation axes of the rollers are tilted relative to the center axis of the bearing. The retainer maintains the distance between adjacent rollers. In the gear power transmission device, the outer peripheral surface of the inner race and the inner peripheral surface of the outer race are not provided with ribs for restricting the movement of the rollers in the rotation axis direction. A groove for receiving the large-diameter-side end of the retainer is provided in either the case or the carrier.

Description

Gear transmission

The present application claims priority based on Japanese Patent Application No. 2014-009579, filed Jan. This specification discloses techniques relating to gear transmissions.

It is known that the carrier rotates relative to the gearbox and the carrier or gearbox constitutes the gearing of the output. In such a gear transmission, the carrier is supported by the gearbox via bearings. A gear transmission device in which a cylindrical roller bearing is disposed between a gear case and a carrier is disclosed in Japanese Laid-Open Patent Publication No. 2010-159774. In the following description, Japanese Laid-Open Patent Publication No. 2010-159774 is referred to as Patent Document 1. The cylindrical roller bearing roller of the patent document 1 has a rotating shaft that is inclined with respect to the bearing center axis to constitute a bevel roller bearing. The bevel roller bearing of Patent Document 1 is attached to the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring, and is not provided with a retaining ring for restricting the movement of the roller in the direction of the rotation axis.

In the case where the rotating shaft of the roller is inclined with respect to the central axis of the bearing, in the driving of the gear transmission, the force acting on the roller causes the roller to move outward in the direction of the rotating shaft. In Patent Document 1, the end portion on the large diameter side of the retainer is brought into contact with the gear case to restrict the roller from moving outward. That is, when the roller is to be moved outward, the outer end of the large diameter side of the retainer is in contact with the gear case, and the roller is restricted from moving in the axial direction. However, if the force applied to the roller increases, the retainer slides relative to the gearbox, which may result in an inability to limit the movement of the roller. As a result, the rollers contact the gearbox, causing wear of the rollers and/or the gearbox. This manual is a solution Those who have made the above problems reveal that the roller is more reliably restrained from moving in the axial direction.

The technology disclosed in this specification relates to a gear transmission in which a carrier is supported by a gearbox via a bearing. The bearing has an inner ring disposed on the carrier, an outer ring disposed on the gear case, a plurality of rollers disposed between the inner ring and the outer ring, and a retainer that maintains the spacing of adjacent rollers. The roller has a rotational axis that is inclined with respect to the central axis of the bearing. In the above bearing, the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring are not provided with a retaining ring for restricting the movement of the roller in the direction of the rotation axis of the roller. In the gear transmission disclosed in the present specification, a groove for accommodating the end portion on the large diameter side of the retainer is provided in either of the gear case and the carrier.

According to the above-described gear transmission, when the roller acts to move the roller outward in the direction of the rotation axis, the large diameter side of the retainer is accommodated in the groove. Even if the force for moving the roller in the axial direction is increased, the retainer remains in the groove, so that the roller is prevented from moving further outward. The above-described gear transmission can more reliably limit the movement of the roller in the direction of the rotation axis than the previous gear transmission.

In addition, the term "the inner ring is disposed on the carrier" includes not only the form in which the inner ring of the different parts of the carrier is fixed to the carrier, but also includes the outer surface of the carrier to operate the carrier as an inner ring. form. Similarly, the term "the outer ring is disposed in the gear box" includes not only the outer ring of the gear box but also the outer ring of the gear box, and the inner casing of the gear box is used to make the gear box function as an outer ring. The form of function.

2‧‧‧Gear rack

2a‧‧‧1st tablet

2b‧‧‧ Column

2c‧‧‧2nd tablet

4‧‧‧through holes

6‧‧‧2nd bearing

6a‧‧‧2nd bearing

6b‧‧‧2nd bearing

8‧‧‧Axis

8a‧‧‧Axis

8b‧‧‧Axis

10‧‧‧ crankshaft

12‧‧‧ oil seal

14‧‧‧ external gear

14a‧‧‧ external gear

14b‧‧‧ external gear

16‧‧‧ bearing

16a‧‧‧ Bearing

16b‧‧‧ Bearing

18‧‧‧Eccentric body

18a‧‧‧Eccentric body

18b‧‧‧Eccentric body

22‧‧‧ input gear

24‧‧‧Rotary axis

26‧‧‧ bearing central axis

30‧‧‧ Inner Ring

32‧‧‧ retaining ring

32a‧‧‧The Great Trails Department

32b‧‧‧a little dotted line

34‧‧‧Roller

36‧‧‧Outer Ring

38‧‧‧Rolling axis of the roller

40‧‧‧ Bearing (1st bearing)

44‧‧‧ internal gear

46‧‧‧ Gearbox

48‧‧‧ Gearbox

50‧‧‧ Inner Ring

52‧‧‧ retaining ring

54‧‧‧Roller

56‧‧‧Outer Ring

58‧‧‧Rotary axis

60‧‧‧1st bearing

62‧‧‧ slots

100‧‧‧Gear transmission

200‧‧‧Gear transmission

202‧‧‧Gear rack

202c‧‧‧2nd tablet

230‧‧‧ Inner Ring

232‧‧‧ retaining ring

232a‧‧‧Great Path Department

232b‧‧ Direction

234‧‧‧Roller

236‧‧‧ outer ring

238‧‧‧Rotary axis

240‧‧‧1st bearing

262‧‧‧ slot

300‧‧‧Gear transmission

302‧‧‧Gear rack

302a‧‧‧1st tablet

302b‧‧‧ Column

302c‧‧‧2nd tablet

332‧‧‧ retaining ring

332a‧‧‧The Great Trails Department

332b‧‧ Direction

340‧‧‧1st bearing

346‧‧‧ Gearbox

348‧‧‧ internal gear

352‧‧‧ retaining ring

360‧‧‧1st bearing

362‧‧‧ slots

400‧‧‧Gear transmission

402‧‧‧Carriage

402c‧‧‧2nd tablet

430‧‧‧ Inner Ring

432‧‧‧ retaining ring

432a‧‧‧Great Path Department

432b‧‧ Direction

440‧‧‧1st bearing

II‧‧‧dotted line

V‧‧‧ dotted line

θ ₁ ‧‧‧ angle

θ ₂ ‧‧‧ angle

θ ₃ ‧‧‧ angle

θ ₄ ‧‧‧ angle

Fig. 1 is a cross-sectional view showing the gear transmission of the first embodiment.

Fig. 2 is an enlarged cross-sectional view showing a portion surrounded by a broken line II of Fig. 1.

Figure 3 is an enlarged cross-sectional view showing a portion of the gear transmission of the second embodiment.

Figure 4 is a cross-sectional view showing the gear transmission of the third embodiment.

Fig. 5 is an enlarged cross-sectional view showing a portion surrounded by a broken line V of Fig. 4.

Figure 6 is an enlarged cross-sectional view showing a portion of the gear transmission of the fourth embodiment.

Fig. 7 is a view showing the features of the retainer of the first and third embodiments.

Fig. 8 is a view showing the features of the retainer of the second and fourth embodiments.

Hereinafter, a number of technical features of the gear transmission disclosed in the present specification will be described. In addition, the matters described below are individually technically applicable.

The gear transmission has a carrier and a gear box. The carrier is rotatably supported by the gearbox via bearings. A plurality of gears are housed in the gearbox. The gear transmission further includes a crankshaft, an eccentric rotating gear, and a rotating gear. The crankshaft is rotatably supported by the carrier. The crankshaft has an eccentric body. The eccentric rotating gear train is engaged with the eccentric body of the crankshaft and eccentrically rotates as the crankshaft rotates. The rotation gear train meshes with the eccentric rotation gear and has a different number of teeth than the number of teeth of the eccentric rotation gear. The eccentric rotating gear is an external gear, and the rotating gear is an internal gear. Internal teeth are provided on the inner circumference of the gear case, and the gear box doubles as an internal gear.

The above bearing has an inner ring, an outer ring and a plurality of rollers. The inner ring is disposed on the carrier. Further, the inner ring is fixed to the outer peripheral surface of the carrier, and the outer peripheral surface of the carrier functions as an inner ring. The outer ring is placed in the gearbox. The outer ring is fixed to the inner circumferential surface of the gear case, and the inner circumferential surface of the gear case functions as an outer ring. A plurality of rollers are disposed between the inner ring and the outer ring.

On the outer circumference of the inner ring, a retaining ring for restricting the movement of the roller in the direction of the rotation axis is not provided. That is, on the outer peripheral surface of the inner ring, the protruding portion that is in contact with the end portion of the roller in the direction of the rotation axis is not provided. Further, on the inner circumferential surface of the outer ring, a retaining ring that restricts the movement of the roller in the direction of the rotation axis is not provided. In other words, the inner peripheral surface of the outer ring is not provided with a protruding portion that contacts the end portion of the roller in the direction of the rotation axis.

The plurality of rollers have a rotational axis that is inclined with respect to a bearing central axis of the bearing. The roller is cylindrical or conical. In the case where the roller is cylindrical, the above bearing is a cylindrical roller bearing (beveled roller bearing). In the case where the roller is conical, the above bearing is a tapered roller bearing. The rotating shaft of the roller is oriented toward the inside of the gear transmission (tooth The center side of the axial direction of the wheel transmission is inclined as it is closer to the bearing center axis of the above bearing. In the case where the above bearing is a tapered roller bearing, the large diameter portion of the small diameter portion of the roller is located further inside the gear transmission.

The above bearing has a retainer that maintains the spacing of adjacent rollers. The retainer is annular and has a large diameter portion and a small diameter portion. The small diameter portion of the retainer is located on the inner side of the gear transmission than the large diameter portion of the retainer. A plurality of holes (recessed holes) are disposed in the circumferential direction of the retainer, and the rollers are disposed in the holes. A groove for accommodating the large-diameter side end portion of the retainer is provided in the gear case. Alternatively, a groove for accommodating the large-diameter side end portion of the retainer is provided to the carrier. The large-diameter side end of the retainer is always in contact with the bottom surface of the groove. Alternatively, the large-diameter side end portion of the retainer may be in contact with the bottom surface of the groove when the roller acts to move the roller outward. The end of the large diameter side of the retainer may be a circle that is rounded around the central axis of the bearing. In other words, the end surface on the large diameter side of the retainer is relatively flat. In this case, the entire circumference of the large diameter side end portion of the retainer is housed in the groove. Alternatively, the large diameter side end surface of the retainer may have irregularities. In other words, the end portion on the large diameter side of the retainer may be in a form in which one of the circumferential directions is partially protruded. In this case, at least one portion (projecting portion) of the large-diameter side end portion of the retainer is housed in the groove.

The large diameter portion of the retainer extends toward the end in a direction different from the rotation axis of the roller. That is, the retainer is bent on the outer side of the outer end surface of the roller (the end surface of the roller on the large diameter side of the retainer) and is curved in a direction different from the rotation axis of the roller. The direction in which the large diameter portion of the retainer extends extends from the central axis of the bearing is smaller than the angle between the rotating shaft of the roller and the central axis of the bearing. In this case, the groove for accommodating the large-diameter side end portion of the retainer can be placed on the carrier. In addition, the "angle of the rotating shaft of the roller and the central axis of the bearing" means "sharp angle". Further, "the angle between the direction in which the large diameter portion of the roller extends and the central axis of the bearing" includes 0 degrees. That is, the large diameter portion of the retainer can extend parallel to the central axis of the bearing.

The direction in which the large diameter portion of the retainer extends extends from the central axis of the bearing is greater than the angle between the rotating shaft of the roller and the central axis of the bearing. The direction in which the large diameter portion of the retainer extends may be 90 degrees from the central axis of the bearing. That is, the side end portion of the large diameter portion of the retainer is orthogonal to the central axis of the bearing. extend.

(First embodiment)

The gear transmission 100 will be described with reference to Fig. 1 . In the following description, components having substantially the same functions will be omitted from the reference numerals of the reference numerals. The gear transmission 100 includes an internal gear 48, a carrier 2, a crankshaft 10, and an external gear 14. The internal gear 48 is provided with a gear case 46 and a plurality of internal tooth pins 44. The gear case 46 surrounds the outer side in the radial direction of the externally toothed gear 14. The inner tooth pin 44 has a cylindrical shape and is disposed on the inner circumferential surface of the gear case 46. The carrier 2 is rotatably supported by the gear case 46 by a pair of first bearings 40 and 60. The internal tooth pin 44 is disposed between the first bearings 40 and 60. The first bearings 40 and 60 restrict the carrier 2 from moving in the axial direction and the radial direction with respect to the gear case 46. In the gear transmission 100, a tapered roller bearing is used as the first bearings 40, 60.

The first bearing 40 is disposed between the gear case 46 and the carrier 2 (second plate 2c). The first bearing 40 includes an inner ring 30, an outer ring 36, a roller 34, and a retainer 32. The inner ring 30 is integral with the carrier 2 . More specifically, the outer peripheral surface of the carrier 2 also serves as the inner ring 30. That is, the inner ring 30 is a part of the carrier 2. The outer ring 36 is mounted to the gearbox 46. The outer ring 36 is embedded in the inner circumferential surface of the gear case 46. The first bearing 40 has a plurality of rollers 34. One of the plurality of rollers 34 is shown in FIG.

The outer circumferential surface of the inner ring 30 and the inner circumferential surface of the outer ring 36 do not have a protruding portion that protrudes toward the rotating shaft 38. That is, the outer circumferential surface of the inner ring 30 and the inner circumferential surface of the outer ring 36 do not have a retaining ring for restricting the movement of the roller 34 in the direction of the rotating shaft 38. The spacing of adjacent rollers 34 from one another is maintained by retainer 32. Specifically, a plurality of holes (not shown) are provided in the circumferential direction of the retainer 32, and the rollers 34 are disposed in the respective holes. The axis of rotation 38 of the roller 34 is inclined relative to the axis 26 of the gear transmission 100. The axis 26 is the rotating shaft of the carrier 2 or the gear case 46, and is also the bearing central axis of the first bearing 40.

The first bearing 60 is disposed between the gear case 46 and the carrier 2 (first plate 2a). The first bearing 60 includes an inner ring 50, an outer ring 56, a roller 54, and a retainer 52. The inner ring 50 and the carrier 2 are One. The outer peripheral surface of the carrier 2 also serves as the inner ring 50. That is, the inner ring 50 is a part of the carrier 2. The outer ring 56 is mounted to the gearbox 46. The outer ring 56 is embedded in the inner circumferential surface of the gear case 46. The first bearing 60 has a plurality of rollers 54.

The outer circumferential surface of the inner ring 50 and the inner circumferential surface of the outer ring 56 do not have a protruding portion that protrudes toward the rotating shaft 38. That is, the outer circumferential surface of the inner ring 50 and the inner circumferential surface of the outer ring 56 do not have a retaining ring for restricting the movement of the roller 54 in the direction of the rotating shaft 58. The spacing of adjacent rollers 54 from one another is maintained by retainer 52. A plurality of holes (not shown) are provided in the circumferential direction of the retainer 52, and the rollers 54 are disposed in the respective holes. The axis of rotation 58 of the roller 54 is inclined relative to the axis 26. The more the rotating shafts 38, 58 are closer to the axis 26 towards the inner side of the gear transmission 100. The angle of inclination of the axis of rotation 38 relative to the axis 26 is equal to the angle of inclination of the axis of rotation 58 with respect to the axis 26. That is, the position at which the rotating shaft 38 and the rotating shaft 58 intersect is located at a midpoint between the first bearing 40 and the first bearing 60 in the direction of the axis line 26.

The carrier 2 includes a first flat plate 2a and a second flat plate 2c. The first flat plate 2a is provided with a columnar portion 2b. The columnar portion 2b extends from the first flat plate 2a toward the second flat plate 2c, and is fixed to the second flat plate 2c. The first flat plate 2a and the second flat plate 2c are detachable. An oil seal 12 is provided between the first flat plate 2a and the gear case 46. Further, the gear transmission 100 is provided with a through hole 4 along the axis line 26. That is, a through hole is provided in the center of the carrier 2 and the external gear 14 .

The crankshaft 10 is supported by the carrier 2 by a pair of second bearings 6. The second bearing 6a is attached to the first flat plate 2a, and the second bearing 6b is attached to the second flat plate 2c. The pair of second bearings 6 restrict the movement of the crankshaft 10 in the axial direction and the radial direction with respect to the carrier 2 . In the gear transmission 100, a tapered roller bearing is used as the pair of second bearings 6.

The crankshaft 10 includes a shaft portion 8 (8a, 8b) and two eccentric bodies 18 (18a, 18b). The eccentric bodies 18a and 18b are provided between the shaft portions 8a and 8b. The second bearing 6 is fixed to the shaft portion 8. Therefore, the eccentric body 18 can also be disposed between the second bearings 6a and 6b. The orientation in which the eccentric body 18a and the eccentric body 18b are eccentric is symmetrical with respect to the rotation axis 24 of the crankshaft 10. The eccentric body 18a is engaged with the externally toothed gear 14a via the axis 16a. The eccentric body 18b is fastened to the external teeth via the bearing 16b Wheel 14b. The cylindrical roller bearing 16 is restricted from moving in the axial direction (direction of the rotating shaft 24) by the second bearing 6.

The input gear 22 is fixed to the shaft portion 8b. The input gear 22 is fixed to the shaft portion 8b on the outer side of the second bearings 6a and 6b. The torque of the motor (not shown) is transmitted to the input gear 22. When the torque of the motor is transmitted to the input gear 22, the crankshaft 10 rotates about the rotation shaft 24. When the crankshaft 10 rotates, the eccentric body 18 rotates eccentrically about the rotation shaft 24. As the eccentric body 18 rotates eccentrically, the externally toothed gear 14 meshes with the internal gear 48 and rotates eccentrically. The external gear 14 is eccentrically rotated about the axis 26. The externally toothed gear 14a and the externally toothed gear 14b are eccentrically rotated symmetrically with respect to the axis 26. The number of teeth of the external gear 14 is different from the number of teeth of the internal gear 48 (the number of the internal gears 44). The externally toothed gear 14 is supported by the carrier 2 via the crankshaft 10. Therefore, when the externally toothed gear 14 is eccentrically rotated, the carrier 2 is rotated with respect to the internal gear 48 (the gear case 46) in accordance with the difference in the number of teeth of the externally toothed gear 14 and the internal gear 48.

The first bearing 40 will be described in detail with reference to Fig. 2 . Further, the structure of the first bearing 60 is substantially the same as that of the first bearing 40. Therefore, the description about the first bearing 60 is omitted.

As shown in FIG. 2, the large diameter portion 32a of the retainer 32 extends in a direction different from the rotation shaft 38. Specifically, the retainer 32 extends from the end portion of the small-diameter portion along the rotating shaft 38 to the end portion on the large-diameter portion 32a side of the roller 34, and is along the end portion of the large-diameter portion 32a side of the roller 34. The bearing center shaft 26 extends to the end of the large diameter portion 32a (see also Fig. 1). The end face of the large diameter portion 32a of the retainer 32 is rounded around the bearing central axis 26. A dotted line 32b of Fig. 2 indicates the direction in which the large diameter portion 32a extends. A dotted line 32b is parallel to the bearing central axis 26. The large diameter side of the retainer 32 may also be curved in a direction different from the rotating shaft 38. Alternatively, the protruding portion 32a protruding in a direction different from the rotating shaft 38 may be provided on the large diameter side of the retainer 32.

In Fig. 7, the angle between the rotating shaft 38 of the roller 34 and the direction 32b of the large diameter portion 32a with respect to the bearing central axis 26 is shown. In addition, FIG. 7 is a diagram for explaining the angle formed by each line (axis), and does not correctly display the position of the actual line (axis). As described above, the direction 32b in which the large diameter portion 32a extends is parallel to the bearing central axis 26. The angle between the bearing center shaft 26 and the direction 32b is 0 degrees. Further, the angle θ ₁ between the bearing central shaft 26 and the rotating shaft 38 is approximately 40 degrees. In other words, the retainer 32 extends from the small diameter side toward the large diameter side to the end portion of the large diameter portion 32a side of the roller 34 at an angle of substantially 40 degrees with respect to the bearing central axis 26, and exceeds the large diameter of the roller 34. The end portion on the side of the portion 32a is then extended parallel to the bearing central axis 26 (at an angle of 0 degrees). The angle between the bearing central shaft 26 and the direction 32b is less than the angle θ ₁ between the bearing central shaft 26 and the rotating shaft 38.

As shown in FIG. 2, a groove 62 is provided in the carrier 2. The slot 62 is circumferential about the axis 26. The groove 62 is formed at a position facing the end surface of the large diameter portion 32a. The groove 62 accommodates the end of the large diameter portion 32a. As described above, the end surface of the large diameter portion 32a is rounded around the bearing central axis 26. Therefore, the entire circumference of the large diameter portion 32a is accommodated in the groove 62. When a force is applied to the roller 34 to move the roller 34 outward (in the direction of the rotating shaft 38 in the direction of the outer side of the gear transmission 100), the retainer 32 moves outward together with the roller 34, and the retainer 32 contacts Carrier 2. The movement of the retainer 32 is limited, and as a result, the movement of the roller 34 in the direction of the rotating shaft 38 is restricted. Similarly, when a force for moving the roller 54 outward is applied to the roller 54, the movement of the retainer 52 is restricted, and the restricting roller 54 is moved in the direction of the rotating shaft 38 (refer to FIG. 1).

The advantages of the gear transmission 100 will be described. The first bearing 40 has the same advantages as the first bearing 60. Therefore, only the first bearing 40 will be described below, and the description of the first bearing 60 will be omitted. When the gear transmission 100 is driven, the roller 34 is biased to move the roller 34 outward. The inner ring 30 and the outer ring 36 do not have a retaining ring that limits the movement of the rollers 34. Therefore, the inner ring 30 and the outer ring 36 are not in contact with each other at the end of the roller 34 in the direction of the rotating shaft 38. The roller 34 can be prevented from being worn.

As described above, the movement of the rollers 34 toward the outside is restricted by the contact of the retainer 32 with the carrier 2. More specifically, the end surface of the large diameter portion 32a of the retainer 32 contacts the bottom surface of the groove 62, thereby restricting the movement of the roller 34. When the retainer 32 contacts the bottom surface of the groove 62, the end portion of the large diameter portion 32a of the retainer 32 is housed in the groove 62. Even if the force for moving the roller 34 to the outside is increased, the retainer 32 remains in the groove 62, and the roller 34 can be restricted from moving outward.

The gear transmission 100 is attached to the retainer 32 after contacting the carrier 2, as long as the retainer 32 is not If it is damaged, the roller 34 can be continuously moved to the outside. On the other hand, the conventional gear transmission device restricts the roller from moving outward by abutting the large diameter portion of the retainer against the gear case as described above. Therefore, when the force for moving the roller outward is increased, the retainer slides relative to the gear case, and the movement of the roller cannot be restricted. The gear transmission 100 can more reliably limit the movement of the rollers as compared to previous gear transmissions.

As can be seen from Fig. 1, the large diameter portion 32a of the retainer 32 does not contact the gear case 46. Therefore, it is possible to prevent the gap between the gear case 46 and the carrier 2 from being blocked due to the retainer 32. The gear transmission 100 is easy for the lubricant or the like to move inside and outside the first bearing 40.

(Second embodiment)

The gear transmission 200 will be described with reference to Fig. 3 . The gear transmission 200 is a modification of the gear transmission 100, and the same components as those of the gear transmission 100 are denoted by the same reference numerals or the same numerals are designated by the same reference numerals, and the description thereof will be omitted. The gear transmission 200 differs from the gear transmission 100 in that the first bearing forms a cylindrical roller bearing (beveled roller bearing). Figure 3 shows only a portion of the gearing 200 (corresponding to the portion of Figure 2). Further, the gear transmission 200 is provided with a pair of first bearings similarly to the gear transmission 100 (see also FIG. 1). However, hereinafter, only the first bearing 240 provided between the gear case 46 and the second flat plate 202c will be described. Again, other configurations of the gear transmission 200 are substantially identical to the gear transmission 100.

The first bearing 240 includes an inner ring 230, an outer ring 236, a roller 234, and a retainer 232. The outer peripheral surface of the carrier 202 (202c) also serves as the inner ring 230. The outer circumferential surface of the inner ring 230 and the inner circumferential surface of the outer ring 236 are inclined at an oblique angle with respect to the axis 26. The roller 234 is cylindrical. The large diameter portion 232a of the retainer 232 extends in a direction 232b different from the rotation shaft 238.

8 shows the angle of the rotating shaft 238 of the roller 234 and the direction 232b of the large diameter portion 232a with respect to the bearing central axis 26. The direction 232b in which the large diameter portion 232a extends is parallel to the bearing central axis 26. That is, the angle between the bearing central axis 26 and the direction 32b is 0 degrees. Further, the angle θ ₃ between the bearing central shaft 26 and the rotating shaft 238 is approximately 45 degrees. The angle between the bearing central shaft 26 and the direction 32b is less than the angle θ ₃ between the bearing central axis 26 and the rotational axis 238.

(Third embodiment)

The gear transmission 300 will be described with reference to Figs. 4 and 5 . The gear transmission 300 is a modification of the gear transmission 100, and the same components as those of the gear transmission 100 are denoted by the same reference numerals or the same numerals are denoted by the same reference numerals, and the description thereof will be omitted. The gear transmission 300 differs from the gear transmission 100 in the configuration of a pair of first bearings 340, 360 and the configuration thereof. In the following description, the first bearing 340 will be described, and the description of the first bearing 360 will be omitted.

The first bearings 340 and 360 are disposed between the gear case 46 and the carrier 2 . The first bearing 340 is disposed between the gear case 46 and the carrier 2 (second plate 2c), and the first bearing 360 is disposed between the gear case 46 and the carrier 2 (first plate 2a). The first bearing 340 includes an inner ring 30, an outer ring 36, a roller 34, and a retainer 332. The large diameter portion 332a of the retainer 332 extends in a direction 332b different from the rotating shaft 38. The retainer 332 extends from the end of the small diameter portion to the end portion of the large diameter portion 32a of the roller 34 so as to be spaced apart from the bearing central shaft 26 along the rotating shaft 38. Further, the retainer 332 extends from the end portion of the large diameter portion 332a side of the roller 34 to the end portion of the large diameter portion 332a so as to be spaced apart from the bearing central shaft 26 at a steeper angle than the rotating shaft 38. The large diameter portion 332a extends toward the gear case 346.

The groove 362 is disposed in the gear case 346. The slot 362 is circumferential about the axis 26. The end of the large diameter portion 332a is received in the groove 362. The gear transmission 300 is the same as the gear transmission 100. Even if the roller 34 is biased to move the roller 34 outward, the retainer 32 remains in the groove 362, so that the roller 34 can be restricted from moving outward.

As shown in FIG. 7, the angle θ _{2 of the} bearing central axis 26 and the direction 332b is greater than the angle θ _{1 of the} bearing central axis 26 and the rotational axis 38. The angle θ ₂ is approximately 90 degrees and the angle θ ₁ is approximately 40 degrees. In other words, the retainer 332 extends from the small diameter side toward the large diameter side to the end portion of the large diameter portion 32a side of the roller 34 at an angle of substantially 40 degrees with respect to the bearing central axis 26, and exceeds the large diameter of the roller 34. The end portion of the portion 32a side is separated from the bearing center shaft 26 in such a manner as to extend orthogonal to the bearing center shaft 26.

(Fourth embodiment)

The gear transmission 400 will be described with reference to Fig. 6 . The gear transmission 400 is a variation of the gear transmissions 200, 300. The same components as those of the gear transmissions 200 and 300 are denoted by the same reference numerals or the same numerals are denoted by the same reference numerals, and the description thereof will be omitted. The gear transmission 400 is different from the gear transmission 200 in that a groove 362 that receives an end portion of the large diameter portion 432a of the retainer 432 is disposed in the gear case 362 (see also FIG. 3). Alternatively, the gear transmission 400 differs from the gear transmission 300 in that the first bearing 440 forms a cylindrical roller bearing (beveled roller bearing) (see also FIG. 5). In the following description, only the first bearing 440 provided between the gear case 346 and the second flat plate 402c will be described in the pair of first bearings.

The first bearing 440 includes an inner ring 430, an outer ring 236, a roller 234, and a retainer 432. The outer peripheral surface of the carrier 402 (402c) doubles as the inner ring 430. The large diameter portion 432a of the retainer 432 extends in a direction 432b different from the rotation shaft 238. The retainer 432 extends from the end of the small diameter portion to the end surface on the large diameter portion 432a side of the roller 234, and is separated from the bearing central shaft 26 along the rotating shaft 238. Further, the retainer 432 extends from the end surface on the large diameter portion 432a side of the roller 234 to the end portion of the large diameter portion 432a so as to be spaced apart from the bearing central shaft 26 at a steeper angle than the rotating shaft 238. The large diameter portion 432a extends toward the gear case 346.

As shown, the central axis 26 and the direction of the bearing angle θ 8 ₄ 432b of the center shaft 26 is larger than the bearing angle of the rotation shaft 238 θ _3. The angle θ4 is approximately 90 degrees and the angle θ ₃ is approximately 45 degrees. In other words, the retainer 432 extends from the small diameter portion side toward the large diameter portion side to the end portion of the large diameter portion 432a side of the roller 234 at an angle of substantially 45 degrees with respect to the bearing central axis 26, and exceeds the roller 234. The end portion on the large diameter portion 432a side is separated from the bearing center shaft 26 so as to extend in a direction orthogonal to the bearing center shaft 26.

In the above embodiment, the shape in which the end surface on the large diameter side of the retainer is rounded around the central axis of the bearing will be described. Because the retaining ring can accommodate the entire circumference of the large diameter portion in the groove Therefore, it has the advantage of easily restricting the movement of the retainer. The technique disclosed in the present specification can also be applied to the end face on the large diameter side of the retainer to have a shape of irregularities. When the end face of the retaining ring contacts the bottom surface of the groove, the retaining ring can reduce the contact area, and can reduce the friction between the gear box (or the carrier) and the retaining ring.

The specific examples of the present invention have been described in detail above, but are not intended to limit the scope of the patent application. The technology described in the patent application scope includes various changes and modifications of the specific examples exemplified above. The technical elements described in the specification or the drawings are technically usable individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Moreover, the technology exemplified in the specification or the drawings simultaneously achieves a plurality of objects, and the technology for achieving one of the objectives is technically practical.

2‧‧‧Gear rack

2c‧‧‧2nd tablet

30‧‧‧ Inner Ring

32‧‧‧ retaining ring

32a‧‧‧The Great Trails Department

32b‧‧‧a little dotted line

34‧‧‧Roller

36‧‧‧Outer Ring

38‧‧‧Rotary axis

40‧‧‧1st bearing

46‧‧‧ Gearbox

62‧‧‧ slots

100‧‧‧Gear transmission

Claims (6)

A gear transmission device, wherein a carrier is supported by a gear box via a bearing, the bearing includes: an inner ring disposed on the carrier; an outer ring disposed on the gear box; and a plurality of rollers disposed on the inner ring and Between the outer rings, and including a rotating shaft inclined with respect to the central axis of the bearing; and a retainer that maintains the spacing between adjacent rollers; and the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring are not provided for A retaining ring that restricts the movement of the roller in the direction of the rotation axis; and a groove for receiving the end portion of the large diameter side of the retainer ring in either of the gear case and the carrier. The gear transmission of claim 1, wherein the large diameter portion of the retainer extends toward the end in a direction different from the direction of the rotation axis. The gear transmission of claim 2, wherein the direction in which the large diameter portion of the retainer extends extends from the central axis of the bearing is smaller than the angle between the rotating shaft and the central axis of the bearing, and the groove is formed in the carrier. A gear transmission according to claim 3, wherein the large diameter portion of the retainer extends parallel to the central axis of the bearing. The gear transmission of claim 2, wherein the direction in which the large diameter portion of the retainer extends extends from the central axis of the bearing is greater than the angle between the rotating shaft and the central axis of the bearing, and the groove is formed on the inner circumferential surface of the gear case. A gear transmission according to claim 5, wherein the large diameter portion of the retainer extends in a direction orthogonal to the central axis of the bearing.