JP2002161948A - Inner pin supporting structure for planetary gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inner pin supporting structure for planetary gears, which increases rigidity of the carrier and inner pins. SOLUTION: The planetary gear 10 is provided with an input shaft 14 which is supported rotatably and coaxially in a hollow case 12, and an output shaft 16. The input shaft 14 is provided with an eccentric body 24, a flange section 26 and an eccentric body 28. On the eccentric body 24 and eccentric body 28, external gears 36 and 38 are mounted rotatably. On the cylindrical outer periphery of the flange section 26, a spacer 40 is mounted. The spacer 40 is located between the external gears 36 and 38 slidably against the opposite surface of each external gear 36 or 38. By assembling the external gears 36 and 38 and the spacer 40 without a clearance each other, deformation of the external gears 36 and 38 is suppressed. Such a structure suppresses distortion or bending of the inner pins 56 although the inner pins 56 are supported with one side on the carrier 16 as cantilevers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner pin support structure for a planetary gear type speed reducer. More specifically, the present invention provides
The present invention relates to an inner pin support structure capable of supporting an inner pin for extracting a rotation output from an input shaft to an output shaft by an input shaft to increase the strength and rigidity of a planetary gear type speed reducer.

[0002]

2. Description of the Related Art A planetary gear type speed reducer to which the present invention is applied is disclosed, for example, in JP-A-2000-161376. The planetary gear type speed reducer described in the above publication is used, for example, in a cyclo (registered trademark) speed reducer, and an input shaft rotatably supported by a case and two or more shafts provided on the input shaft and separated from each other in the axial direction. An eccentric body, an external gear provided with an inner pin hole that is attached to each eccentric body via a bearing and penetrates in the axial direction, and an internal gear that is attached to the case and inscribedly meshes with the external gear. And a carrier for supporting the inner pin from both sides of the eccentric body. Input axis is 1
When rotated, each eccentric also makes one rotation. By one rotation of the eccentric body, each external gear rotates in an oscillating manner while being inscribed in the internal gear around the input shaft. If the number of teeth of the external gear is N and the number of teeth of the internal gear is N + 1, the external gear rotates by one tooth with respect to the internal gear for each rotation of the input shaft. In the rotation of the external gear, a swing component is absorbed by a gap between the inner pin and the inner pin hole, and only the rotation component is transmitted to the pair of carriers serving as the output shaft while the inner pin is in contact with the inner pin hole. As a result, rotation is transmitted from the input shaft to the output shaft at a reduction ratio of -1 / N.

[0003]

In this type of planetary gear type reduction gear, rotation and power are transmitted from the input shaft to the carrier by the inner pin inscribed in the inner pin hole. Very important. However, in the above-mentioned planetary gear type speed reducer, the inner pin has a double-supported structure supported by a pair of carriers arranged outside the eccentric body, and each carrier is connected to the case and the input shaft by bearings both inside and outside. It is rotatably supported. There is a gap in the bearing itself, and furthermore, the fitting accuracy between the pair of carrier and the inner pin, the inner pin hole and the inner pin hole also depend on the fitting between the bearing and the case and the carrier, and between the bearing and the input shaft and the carrier. It affects the assembly accuracy with the pin. Under such circumstances, the processing accuracy and the mounting accuracy of the external gear, the carrier and the inner pin are required at an extremely strict level. Therefore, in order to support a plurality of inner pins with a carrier and smoothly contact the inner pins along the inner pin holes, a very high level of processing accuracy and assembly accuracy that is practically unproductive is required. Become. As a result, the strength and rigidity near the carrier are reduced, the rotation of the carrier is irregular due to the unstable contact between the inner pin hole and the inner pin, and the noise of the planetary gear type reducer is reduced. There is a problem of growing.

An object of the present invention is to provide an inner pin support structure of a planetary gear type speed reducer which solves the above-mentioned problem by increasing the rigidity of a carrier and an inner pin.

[0005]

SUMMARY OF THE INVENTION The present invention provides an input shaft and an output shaft rotatably supported by a case, two or more eccentric members provided on the input shaft and separated from each other in the axial direction, and each eccentric member. An external gear attached to the body via a bearing and having an internal pin hole penetrating in the axial direction; an internal gear attached to the case and inscribedly meshing with the external gear; and an internal gear attached to the output shaft. In a planetary gear type reduction gear provided with an inner pin that is loosely fitted and inscribed in a pin hole, an input shaft is provided with a flange portion having an outer peripheral surface coaxial with the input shaft between adjacent eccentric bodies, and This problem has been solved by the inner pin support structure of the planetary gear type speed reducer, which is slidably mounted on the outer peripheral surface of the portion and the opposing surface of the adjacent external gear and has a spacer for supporting the inner pin.

[0006] When the input shaft rotates, the eccentric body also rotates. The external gear meshes with the internal gear, and swings and rotates due to the rotation of the eccentric body. When the eccentric body makes one rotation, the external gear rotates by one tooth. This allows
The external gear rotates the inner pin along the inner pin hole, and rotates the output shaft. The input shaft is provided with a flange portion having an outer peripheral surface concentric with the input shaft formed between adjacent eccentric bodies, and a spacer is slidably provided on the outer peripheral surface of the flange portion. . In this way, the spacer is supported concentrically with respect to the input shaft. The spacer also
The spacer is also slidable on the opposing surface of the external gear mounted on each eccentric body through a bearing. It is guided on opposite faces of the gear. Since the spacer supports the inner pin, the input shaft, the spacer, the respective external gears and the inner pin correct each other's posture, and the transmission from the input shaft to the inner pin is stabilized. Thereby, the strength and rigidity of the entire planetary gear type reduction gear including the carrier are improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an inner pin support structure for a planetary gear type speed reducer according to the present invention will be described below with reference to the drawings. 1 is a sectional view of a planetary gear type speed reducer, and FIG.
FIG. 3 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 3 is a sectional view taken along line 3-3 of FIG. The planetary gear type speed reducer 10 includes a concentric input shaft 14 and an output shaft 16 rotatably supported in a hollow case 12. The output shaft 16 is rotatably supported on the case 12 via a bearing 18, and the input shaft 14 is rotatably supported on the output shaft 16 via a bearing 20. However, the input shaft 14 may be rotatably supported in another case or the like. The input shaft 14 is connected at one end of the case 12 to a drive source such as a motor (not shown). The output shaft 16 is connected to a driven member (not shown) at the other end of the case 12. Input shaft 1
Power is transmitted to the output shaft 16 at a predetermined reduction ratio from the case 4 and the planetary gear type reduction gear 10 including the input shaft 14 and the output shaft 16.

The input shaft 14 is connected to the eccentric body 2 from the base end 22.
4, a flange portion 26, an eccentric body 28 and a tip portion 30. The base 22 is connected to a drive source such as a motor. As shown in FIGS. 2 and 3, the eccentric bodies 24 and the eccentric bodies 28 are formed such that the respective cylindrical outer peripheral surfaces are eccentric with respect to the input shaft 14 by the same distance. The flange portion 26 has a cylindrical outer peripheral surface formed concentrically with the input shaft 14 between the respective eccentric bodies 24 and 28. External gears 36 and 38 are rotatably mounted on the respective cylindrical outer peripheral surfaces of the eccentric body 24 and the eccentric body 28 via bearings 32 and 34 whose axial movement is restricted by circlips. The cylindrical outer peripheral surface of the flange portion 26 is formed larger than the respective cylindrical outer peripheral surfaces of the eccentric body 24 and the eccentric body 28, and the spacer 40 is attached before mounting the bearings 32 and 34. The inner peripheral surface of the spacer 40 is configured as a sliding bearing with respect to the outer peripheral surface of the flange portion 26.
Is rotatable with respect to the input shaft 14, particularly with reference to the cylindrical outer peripheral surface of the flange portion 26. The thickness of the spacer 40 is equal to the distance between the opposing surfaces of the external gears 36 and 38 adjacent to each other.
38 and can slide freely.

In the hollow portion 42 of the case 12, the internal gears 44 mesh with the teeth of the external gears 36 and 38, respectively.
Are attached by bolts. When the input shaft 14 rotates, the external gears 36, 38
The external gears 36 and 38 revolve by one tooth relative to the internal gear 44 by one rotation of the input shaft 14. Each of the external gears 36 and 38 has a plurality of internal pin holes 50 and 52 in the same phase. The spacer 40 also has a pin support hole 54 in the same phase as the internal pin holes 50 and 52 of the external gear.
It has. The inner pin 56 is connected to the proximal end 22 of the input shaft 14.
Through the end portion 30 and is cantilevered by a carrier serving as the output shaft 16. Each inner pin 56
Are loosely fitted into the inner pin holes 50 and 52 of the external gears 36 and 38 and penetrate through the pin support holes 54 of the spacer 40 with a small gap. When the external gears 36 and 38 revolve, the inner pin 56 is pressed in the rotational direction along the inner pin holes 50 and 52. Thereby, the carrier 16 rotates.

The present invention is characterized by the spacer 40.
The spacer 40 includes an input shaft 14, an output shaft (carrier) 16
It is attached to the cylindrical outer peripheral surface of the flange portion 26 so as to be rotatable coaxially with the rotation axis of the inner pin 56 and the revolving axis of the inner pin 56, and rotatably supports the inner pin 56 with a small gap. By doing so, the inner pin 56 is
Even if it is cantilevered, deformation and bending are suppressed.
Since the inner pin 56 is maintained in an appropriate posture by the spacer 40, the dimensions of the inner pin 56 can be finished with high accuracy, and the assembly accuracy of the external gears 36 and 38 and the output shaft (carrier) 16 with respect to the inner pin 56 can be increased. By adding the spacer as one part without causing any trouble, the same performance as that of the conventional planetary gear type speed reducer can be exhibited, and a mass production effect can be obtained.

The spacer 40 is provided with external gears 36, 3
8, each of the external gears 36, 3
8 is slidably mounted on the opposing surface of the motor. By combining the external gears 36, 38 and the spacer 40 without any gap, deformation of the external gears 36, 38 is suppressed.

When the inner pin 56 is cantilevered, the size of the entire planetary gear type speed reducer can be reduced, but the strength and rigidity of the inner pin 56 must be sacrificed. By supporting each of the inner pins 56 around the input shaft 14 via the spacer 40 around the inner pin 56, strength and rigidity can be supplemented by the spacer 40. Therefore, the strength and rigidity of the inner pin 56 can be maintained by the spacer 40 even if the inner pin 56 is cantilevered, as compared with a planetary gear type speed reducer that supports the inner pin 56 at both ends. .

[0013]

According to the present invention, as described in detail above, a flange is provided on the input shaft, and the spacer is slidably mounted on the outer peripheral surface of the flange and the opposing surface of the adjacent external gear. Supports the inner pin, the input shaft corrects the posture of the inner pin as well as the external gear. This allows
The operation of the external gear and the inner pin is stabilized, and the strength and rigidity of the inner pin, and thus the strength and rigidity of the carrier, can be increased. Therefore, even if the external gear and the inner pin do not have to be finished with high precision, the inner pin operates smoothly along the inner pin hole. A stable operation can be performed by the type speed reducer. Also, if the inner peripheral surface of the spacer is configured as a sliding bearing, the posture of the inner pin can be corrected based on the input shaft, so that the contact state between the inner pin hole and the inner pin is stabilized, and the inner pin hole and the inner pin are This has the effect of reducing the noise due to the collision of the vehicle.

[Brief description of the drawings]

FIG. 1 is a sectional view of a planetary gear type speed reducer employing an inner pin support structure according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Planetary gear type speed reducer 12 Case 14 Input shaft 16 Output shaft (carrier) 18, 20 Bearing 22 Base end 24 Eccentric body 26 Flange part 28 Eccentric body 30 Tip part 32, 34 Bearing 36, 38 External gear 40 Spacer 42 Hollow part 44 Internal gear 46 Pin 48 Bolt 50,52 Inner pin hole 54 Pin support hole 56 Inner pin

Continued on the front page (72) Inventor Katsumi Maejima 4-17-96, Tsurumi-ku, Tsurumi-ku, Osaka-shi, Osaka F-term in Tsubakimoto Chain Co., Ltd.

Claims (1)

[Claims] An input shaft and an output shaft rotatably supported by a case, two or more eccentric members provided on the input shaft and separated from each other in an axial direction, and each of the eccentric members is mounted via a bearing. An external gear having an internal pin hole that penetrates in the axial direction, an internal gear that is attached to the case and inscribedly meshes with the external gear, and an internal gear that is attached to the output shaft and has a free-fit internal contact with the internal pin hole. A planetary gear type speed reducer having a pin and an input shaft provided with a flange portion having an outer peripheral surface coaxial with the input shaft between adjacent eccentric bodies, and an outer peripheral surface of the flange portion and an adjacent outer surface. An inner pin support structure of a planetary gear type speed reducer, which is slidably mounted on an opposing surface of a tooth gear and has a spacer for supporting an inner pin.