Differential gear reducer

Abstract

To provide a differential gear speed reducer capable of suppressing enlargement.SOLUTION: The planetary reduction gear 100 includes a planetary 1a and a 1b that eccentrically rotate, internal teeth 2 having gears that mesh with the planetary gears, a carrier-supporting plate 11 and an output-side flange 12 that are disposed so as to face each other with the planetary gears interposed therebetween, and carrier-side pins 13 that are disposed so as to pass through through-holes 14 provided in the planetary gears and that fasten the carrier-supporting plate and the output-side flange to each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a differential gear reducer. [Background technology]

[0002] A differential gear reducer using a hypocycloid mechanism is known as a reducer that can achieve a high reduction ratio. A conventional differential gear reducer disclosed in Patent Document 1 includes internal gears, planetary gears that mesh with the internal gears, a crankshaft that rotates the planetary gears in an oscillating manner, and an output flange that is connected to the crankshaft via a bearing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6479613 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional differential gear reducers, an auxiliary member is provided on the output flange to connect to a mating member in order to transmit rotational power to the mating member in robot applications, etc. This has posed a problem of making the differential gear reducer large in size.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a differential gear reducer that can prevent an increase in size. [Means for solving the problem]

[0006] The differential gear reducer disclosed herein is a differential gear reducer having eccentrically rotating planets, internal teeth having gears that mesh with the planets, a carrier support plate and an output flange arranged opposite each other with the planets in between, and carrier pins arranged to pass through through holes provided in the planets and fasten the carrier support plate and the output flange, and the carrier pins are inserted into carrier pin insertion holes provided in the output flange and pass through the output flange. [Effects of the Invention]

[0007] In the differential gear reducer of the present disclosure, the carrier pins are inserted into carrier pin insertion holes provided in the output flange and pass through the output flange, so that an increase in size can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram for explaining the differential gear reducer according to the first embodiment. [Figure 2] FIG. 10 is a diagram for explaining a differential gear reducer according to a second embodiment. [Figure 3] FIG. 10 is a diagram for explaining a differential gear reducer according to a third embodiment. [Figure 4] FIG. 10 is a diagram for explaining a differential gear reducer according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a differential gear reducer according to an embodiment of the present disclosure will be described in detail with reference to the drawings. Note that the same reference numerals in the various drawings indicate the same or corresponding parts.

[0010] Embodiment 1 Fig. 1 is a diagram for explaining a differential gear reducer according to embodiment 1. The diagram on the right side of Fig. 1 is a side view of a surface perpendicular to the axial direction of the differential gear reducer of this embodiment, and the diagram on the left side of Fig. 1 is a cross-sectional view taken at the position indicated by AA in the diagram on the right side. In addition, in the cross-sectional view on the left side of Fig. 1, a mating member to which rotational power is transmitted is disposed on the right side of the differential gear reducer.

[0011] As shown in FIG. 1, a differential gear reducer 100 of this embodiment includes a cylindrical camshaft 9, two annular planetary gears 1a and 1b attached to the camshaft 9 via rollers 10, an annular internal gear 2 having gears on its inner periphery that mesh with gears attached to the outer peripheries of the two planetary gears 1a and 1b, and an annular carrier support plate 11 and output flange 12 arranged opposite each other with the two annular planetary gears 1a and 1b sandwiched between them. The camshaft 9 rotates eccentrically. The carrier support plate 11 and the output flange 12 are fastened together by a carrier pin 13.

[0012] The carrier pin 13 passes through a through hole 14 formed in the two planetary gears 1a and 1b. The opening diameter of the through hole 14 formed in the two planetary gears 1a and 1b is set to a size such that the two planetary gears 1a and 1b do not come into contact with the carrier pin 13 even when the two planetary gears 1a and 1b rotate eccentrically. The carrier pin 13 comes into contact with the two planetary gears 1a and 1b via a roller 14a provided in the through hole 14. As shown in FIG. 1 , the carrier support plate 11 and the output flange 12 are rotatably mounted on the camshaft 9 via a bearing 15. The rotational centers of the carrier support plate 11 and the output flange 12 overlap with the center axis of the annular internal gear 2. The internal gear 2 is fixed to a case 17 with a bolt 18. The carrier support plate 11 and the output flange 12 are mounted on the case 17 via a bearing 16.

[0013] The carrier comprises a carrier support plate 11, an output flange 12, and a carrier pin 13. When the camshaft 9 rotates eccentrically, the planetary gears 1a and 1b rotate via the rollers 10. At this time, the planetary gears 1a and 1b rotate at a reduced speed in accordance with the ratio between the number of gears provided on the outer periphery and the number of gears in the internal teeth 2. The reduced rotation of the planetary gears 1a and 1b is converted into rotation of the carrier via the carrier pin 13 and the rollers 14a. Through this operation, the differential gear reducer of this embodiment can reduce the rotation of the carrier relative to the rotation of the camshaft 9 and transmit torque proportional to the reduction ratio.

[0014] The two planetary gears 1a, 1b each have four through holes 14 through which the carrier pins 13 pass, which are arranged at equal intervals in the circumferential direction. The carrier pins 13 are inserted into carrier pin insertion holes 19 formed in the output flange 12, and the carrier pins 13 pass through the carrier pin insertion holes 19 and are exposed on the power transmission side. The output flange 12 also has a plurality of bolt holes 20 formed at positions offset in the circumferential direction from the carrier pin insertion holes 19. These bolt holes 20 are used to fasten the output flange 12 to a mating member, which is the target of power transmission, with screws. The portions of the carrier pins 13 exposed on the power transmission side function as knock pins used for alignment when fastening the mating member to the output flange 12.

[0015] In the differential gear reducer configured as described above, the carrier pins 13 are disposed in the through holes 14 of the planetary gears 1a, 1b via the rollers 14a. Therefore, the rotational power of the planetary gears 1a, 1b can be transmitted to the output flange 12 via the carrier pins 13 and the rollers 14a. Furthermore, the output flange 12 is directly fastened to a mating member via the bolt holes 20 provided in the output flange 12, so that the rotational power of the output flange 12 can be transmitted to the mating member. Furthermore, the carrier pins 13 that penetrate the output flange 12 and are exposed on the power transmission side function as knock pins, so that no auxiliary members for power transmission are required. As a result, the differential gear reducer of this embodiment can be prevented from becoming larger without reducing torque transmission performance.

[0016] Although the differential gear reducer of this embodiment has two planets, it may have only one planet. Also, although the differential gear reducer of this embodiment has one internal tooth for two planets, it may have two internal teeth that mesh with the two planets, respectively.

[0017] Embodiment 2 Fig. 2 is a diagram for explaining a differential gear reducer according to embodiment 2. The diagram on the right side of Fig. 2 is a side view of a surface perpendicular to the axial direction of the differential gear reducer of this embodiment, and the diagram on the left side of Fig. 2 is a cross-sectional view taken at the position indicated by AA in the diagram on the right side. In addition, in the cross-sectional view on the left side of Fig. 2, a mating member that transmits rotational power is disposed on the right side of the differential gear reducer.

[0018] The configuration of the differential gear reducer of this embodiment is similar to the configuration of the differential gear reducer of embodiment 1, but the configurations of the carrier pin and output flange are different from those of the differential gear reducer of embodiment 1. The following explanation will focus on the differences from the differential gear reducer of embodiment 1.

[0019] In the differential gear reducer of Embodiment 1, the carrier pins pass through carrier pin insertion holes 19 provided in the output flange and are exposed on the power transmission side, but in the differential gear reducer of this embodiment, the carrier pins are not exposed on the power transmission side. As shown in FIG. 2 , in the differential gear reducer of this embodiment, the carrier pin insertion holes 19 are provided on the surface of the output flange 12 facing the planets 1a and 1b, and terminate inside the output flange 12. Therefore, the carrier pins 13 inserted in the carrier pin insertion holes 19 do not pass through the output flange 12. The end of the carrier pin insertion hole 19 is connected to a knock pin mounting hole 21 provided on the power transmission side of the output flange 12. In the differential gear reducer of this embodiment, the inner diameter of the knock pin mounting hole 21 is smaller than the inner diameter of the carrier pin insertion hole 19.

[0020] In a differential gear reducer configured in this manner, the output flange 12 is directly fastened to a mating member through bolt holes 20 provided in the output flange 12, thereby enabling the rotational power of the output flange 12 to be transmitted to the mating member. Furthermore, because the output flange 12 is provided with knock pin mounting holes 21, attaching knock pins to these knock pin mounting holes 21 eliminates the need for auxiliary members for power transmission. As a result, the differential gear reducer of this embodiment can be prevented from becoming larger without reducing torque transmission performance.

[0021] Embodiment 3 Fig. 3 is a diagram for explaining a differential gear reducer according to embodiment 3. The diagram on the right side of Fig. 3 is a side view of a surface perpendicular to the axial direction of the differential gear reducer of this embodiment, and the diagram on the left side of Fig. 3 is a cross-sectional view taken at the position indicated by AA in the diagram on the right side. In addition, in the cross-sectional view on the left side of Fig. 3, a mating member that transmits rotational power is disposed on the right side of the differential gear reducer.

[0022] The configuration of the differential gear reducer of this embodiment is similar to the configuration of the differential gear reducer of embodiment 2, but the configuration of the output flange is different from that of the differential gear reducer of embodiment 2. The following explanation will focus on the differences from the differential gear reducer of embodiment 2.

[0023] 3, in the differential gear reducer of this embodiment, carrier pin insertion holes 19 are provided on the surface of output flange 12 facing planets 1a, 1b, and terminate inside output flange 12. The ends of carrier pin insertion holes 19 are connected to knock pin mounting holes 21 provided on the power transmission side of output flange 12. In the differential gear reducer of this embodiment, the inner diameter of knock pin mounting holes 21 is larger than the inner diameter of carrier pin insertion holes 19.

[0024] In a differential gear reducer configured in this manner, the output flange 12 is directly fastened to a mating member through bolt holes 20 provided in the output flange 12, thereby enabling the rotational power of the output flange 12 to be transmitted to the mating member. Furthermore, because the output flange 12 is provided with knock pin mounting holes 21, attaching knock pins to these knock pin mounting holes 21 eliminates the need for auxiliary members for power transmission. As a result, the differential gear reducer of this embodiment can be prevented from becoming larger without reducing torque transmission performance.

[0025] In the differential gear reducer of embodiment 2, the inner diameter of the knock pin mounting holes 21 is smaller than the inner diameter of the carrier pin insertion holes 19. Therefore, if the knock pin is long when mounted in the knock pin mounting holes 21, the knock pin may press against the carrier pin 13. If the knock pin presses against the carrier pin 13, the carrier pin 13 may move, causing the differential gear reducer to malfunction. Therefore, in the differential gear reducer of embodiment 2, it is necessary to set a limit on the length of the knock pin. In the differential gear reducer of this embodiment, the inner diameter of the knock pin mounting holes 21 is larger than the inner diameter of the carrier pin insertion holes 19. Therefore, when the knock pin is mounted in the knock pin mounting holes 21, the knock pin will not press against the carrier pin 13. As a result, there is no need to limit the length of the knock pin, and degradation of performance during assembly can be suppressed.

[0026] Embodiment 4 Fig. 4 is a diagram for explaining a differential gear reducer according to embodiment 4. The diagram on the right side of Fig. 4 is a side view of a surface perpendicular to the axial direction of the differential gear reducer of this embodiment, and the diagram on the left side of Fig. 4 is a cross-sectional view taken at the position indicated by AA in the diagram on the right side. In addition, in the cross-sectional view on the left side of Fig. 4, a mating member that transmits rotational power is disposed on the right side of the differential gear reducer.

[0027] The configuration of the differential gear reducer of this embodiment is similar to the configuration of the differential gear reducer of embodiment 2, but the configuration of the output flange is different from that of the differential gear reducer of embodiment 2. The following explanation will focus on the differences from the differential gear reducer of embodiment 2.

[0028] As shown in FIG. 4 , in the differential gear reducer of this embodiment, carrier pin insertion holes 19 are provided on the surface of output flange 12 facing planets 1a, 1b, and terminate inside output flange 12. The ends of carrier pin insertion holes 19 are connected to knock pin mounting holes 21 provided on the power transmission side of output flange 12. In the differential gear reducer of this embodiment, the centers of knock pin mounting holes 21 are offset from the centers of carrier pin insertion holes 19. In the differential gear reducer of this embodiment, the centers of knock pin mounting holes 21 are offset toward the inner diameter side from the centers of carrier pin insertion holes 19. The inner diameter of knock pin mounting holes 21 may be the same as or different from the inner diameter of carrier pin insertion holes 19.

[0029] In a differential gear reducer configured in this manner, the output flange 12 is directly fastened to a mating member through bolt holes 20 provided in the output flange 12, thereby enabling the rotational power of the output flange 12 to be transmitted to the mating member. Furthermore, because the output flange 12 is provided with knock pin mounting holes 21, attaching knock pins to these knock pin mounting holes 21 eliminates the need for auxiliary members for power transmission. As a result, the differential gear reducer of this embodiment can be prevented from becoming larger without reducing torque transmission performance.

[0030] Furthermore, in the differential gear reducer of this embodiment, the knock pin mounting holes 21 are provided at positions offset from the carrier pin insertion holes 19, so when a knock pin is mounted in the knock pin mounting holes 21, the knock pin does not press against the carrier pin 13. As a result, there is no need to limit the length of the knock pin, and performance degradation during assembly can be suppressed. Note that, in the differential gear reducer of this embodiment, the center of the knock pin mounting holes is offset radially inward from the center of the carrier pin insertion holes, but the direction of offset is not limited to this.

[0031] While the present disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not exemplified are conceivable within the scope of the technology disclosed in this specification, including, for example, cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with components of another embodiment. [Explanation of symbols]

[0032] 1a, 1b planet, 2 internal teeth, 9 camshaft, 10 roller, 11 carrier support plate, 12 output flange, 13 carrier pin, 14 through hole, 14a roller, 15, 16 bearing, 17 case, 18 bolt, 19 carrier pin insertion hole, 20 bolt hole, 21 knock pin mounting hole, 100 differential gear reducer.

Claims

1. An eccentrically rotating planet, an internal gear having a gear meshing with the planet; a carrier support plate and an output flange disposed opposite each other with the planetary gear therebetween; a carrier pin disposed through a through hole provided in the planet and fastening the carrier support plate and the output flange, The differential gear reducer according to claim 1, wherein the carrier pin is inserted into a carrier pin insertion hole provided in the output flange and passes through the output flange.

2. An eccentrically rotating planet, an internal gear having a gear meshing with the planet; a carrier support plate and an output flange disposed opposite each other with the planetary gear therebetween; a carrier pin disposed through a through hole provided in the planet and fastening the carrier support plate and the output flange, the output flange has carrier pin insertion holes, into which the carrier pins are inserted, provided on a surface facing the planets, and knock pin mounting holes, which are communicated with the carrier pin insertion holes, provided on the other surface.

3. 3. The differential gear reducer according to claim 2, wherein an inner diameter of the knock pin mounting hole is larger than an inner diameter of the carrier pin insertion hole.

4. 4. The differential gear reducer according to claim 2, wherein the centers of the knock pin mounting holes are offset from the centers of the carrier pin insertion holes.

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