JPH0545294U - Backlash removal mechanism of planetary gear unit - Google Patents

Abstract

(57) [Abstract] [Purpose] To propose a new mechanism to eliminate tooth backlash in planetary gear units. [Structure] The sun gear 2, the planetary gears 4-1 to 4-4, and the internal gear 5 that constitute the planetary gear device 1 are helical gears.
The planetary gears 4-1 and 4-3 are supported by one carrier piece 6a of the two-divided type carrier, and the planetary gears 4-2 and 4-3 are supported.
4 is supported by the other carrier piece 6b. Each planetary gear is supported in a state of being capable of minute movement in the axial direction, and is in a state of being preloaded in the axial direction by a constant elastic force. When the planetary gears are assembled, the planetary gears are forcibly moved in the axial direction minutely to eliminate the backlash.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mechanism for removing tooth backlash in a planetary gear device.

[0002]

[Problems to be solved by conventional techniques and devices]

 In the planetary gear unit, backlash is provided in consideration of machining errors, assembly errors, and tooth interference due to thermal expansion during operation. For this reason, the input side gear and the output side gear have a backlash play with respect to the counterpart fixed to each other.

In order to remove the backlash, the applicant of the present application has previously proposed in Japanese Patent Application No. 2-2334 that the carrier supporting the planetary gear is composed of left and right carrier pieces that are axially divided into two parts. However, we propose a structure in which each carrier piece supports the same number of planetary gears. In a planetary gear device equipped with this two-part carrier, backlash can be removed by twisting alternating carrier pieces in the circumferential direction prior to fastening them with bolts. There is.

An object of the present invention is to propose a new backlash removing mechanism applicable to a planetary gear device having a general structure and a planetary gear device having the above-described two-division type carrier.

[0005]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in the present invention, each gear constituting the planetary gear device, that is, the sun gear, the planetary gear and the internal gear are all helical gears, and the planetary gear is arranged in the axial direction of the device. The carrier is supported in a slightly movable state, and the planetary gear is elastically pressed in the axial direction by elastic preloading means.

When the present invention is applied to a planetary gear device having a two-divided type carrier, the planetary gears supported by the left and right carrier pieces constituting the two-divided type carrier are alternately seen when viewed in the circumferential direction. The elastic preload direction of the planetary gear supported by one carrier piece and the elastic preload direction of the planetary gear supported by the other carrier piece may be set in opposite directions.

[0007]

[Action]

 Each gear of the planetary gear device is a helical gear, and the planetary gear can be slightly moved in the axial direction. Therefore, when a force in the axial direction larger than the elastic force by the elastic preloading means is applied, the planetary gear can be slightly moved in the axial direction. Therefore, at the time of assembling the planetary gears, the planetary gears can be forcibly finely moved in the axial direction so that the respective gears can be engaged in a state where there is substantially no backlash.

[0008]

【Example】

 The configuration of the present invention will be described below with reference to FIGS. 1 and 2. These figures show the case where the present invention is applied to a planetary gear device provided with a two-part type carrier disclosed in Japanese Patent Application No. 2-2334. The planetary gear device 1 shown in the figure has an input shaft 3 on which a sun gear 2 is formed, and four planetary gears 4-1, 4-2, 4-3, 4-4 meshing with the sun gear 2. , An internal gear 5 in which these planetary gears are meshed with each other, and a two-divided type carrier 6 (6a, 6b) that rotatably supports the planetary gears and rotatably supports them around the sun gear 2. It is configured. In this example, the sun gear 2, the planetary gears 4-1, 4-2, 4-3, 4-4 and the internal gear 5 are all helical gears.

In FIG. 1, the two-divided type carrier 6 is located on one side in the direction of the axis 1a with the planetary gears 4-1 to 4-4 sandwiched therebetween, as indicated by a dashed line. The carrier piece 6a and the second carrier piece 6b located on the other side are fastened to each other by fastening bolts (not shown). Here, the four planetary gears 4-1 to 4-4 are arranged in this order in the circumferential direction at equal angular intervals of 45 degrees. Of these, the planetary gears 4-1 and 4-3 are supported by the first carrier piece 6a, and the planetary gears 4-2 and 4-4 are supported by the second carrier piece 6b. In the illustrated example, the output shaft 7 is formed on one carrier piece 6a side.

With reference to FIG. 2, the supporting state of the planetary gears 4-1 to 4-4 by the carrier pieces 6a and 6b will be described by taking the supporting portion of the planetary gear 4-1 as an example. On the outer periphery of the planetary shaft 8 integrally attached to the first carrier piece 6a, a retaining ring 9 is attached to the tip end side thereof, and an annular projection 10 as a spring seat is formed on the base end side thereof. A planetary gear bearing 11 is attached between them, and the planetary gear 4-1 is rotatably supported via the bearing 11. Here, the distance between the retaining ring 9 and the annular projection 10 is set to be slightly larger than the width of the bearing 11, so that the planetary gear 4-1 supported by the bearing 11 as a whole. It is slightly movable in the axial direction.

Between the annular protrusion 10 and the inner race 11 a of the bearing 11, a compression member 12 is arranged. As a whole, the planetary gear 4-1 is pushed by the spring member 12 in the axial direction indicated by the arrow A, and is pressed against the retaining ring 9.

Another planetary gear 4-3 supported by the first carrier piece 6a is also supported by the same structure. The support structure of the planetary gears 4-2 and 4-4 supported by the second carrier piece 6b is the same as the support structure of the planetary gears 4-1 and 4-3 supported by the first carrier piece 6a. It has a mirror image relationship with the structure, and therefore the pressing direction by the elastic force is the opposite direction shown by the dotted arrow B.

The planetary gear device 1 in which the planetary gears are thus supported is assembled in the following procedure. The planetary gears 4-1, 4-3 and 4-2, 4-4 are fixed to the carrier pieces 6a, 6b, respectively. These carrier pieces 6a, 6b are assembled face-to-face with each other via an output bearing (not shown) so that the planetary gears of the respective carrier gears are located between them. In this combination, the planetary gear is moved in the axial direction against the elastic force of the spring member 12 to form a state without backlash with the sun gear 2. In this state, the two carrier pieces 6a and 6b are fastened with fastening bolts (not shown).

As described above, by adopting the mechanism of this example, it is possible to assemble the planetary gear in a state where there is virtually no backlash.

In the above configuration, only the planetary gears supported by one of the carrier pieces 6a or 6b are supported so as to be finely movable in the axial direction, and these are pressed in one axial direction by the spring member. The configuration may be changed.

Further, the above description has been given by taking the planetary gear device including the two-divided type carrier as an example. However, the present invention can be similarly applied to a planetary gear device having a general structure in which the planetary gear is supported by a single carrier.

[0017]

[Effect of the device]

 As described above, the planetary gear device of the present invention employs a configuration in which the planetary gear is pressed by the elastic preload means in a state where it can be slightly moved in the axial direction. Therefore, according to the present invention, when the planetary gear is assembled, the planetary gear can be forcibly moved minutely in the axial direction, and by this movement, the planetary gear can be moved without backlash substantially. It is possible to form a state that meshes with the sun gear.

[Brief description of drawings]

FIG. 1 is a schematic view illustrating a configuration of a backlash removing mechanism of the present invention.

FIG. 2 is an enlarged schematic view showing a structure of a supporting portion of a planetary gear in the mechanism shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Planetary gear device 2 ... Sun gear 4-1, 4-2, 4-3, 4-4 ... Planetary gear 5 ... Internal gear 6a, 6b ... Carrier piece 8 ... -Planetary shaft 9 ... Retaining ring 10 ... Annular protrusion (spring seat) 11 ... Planetary gear bearing 11a ... Inner race 12 ... Spring member

Claims (2)

[Scope of utility model registration request] 1. A sun gear, a planetary gear, and an internal gear that constitute a planetary gear device are helical gears, and the planetary gear is supported on a carrier in a state of being slightly movable in an axial direction, and by elastic preloading means. A backlash removing mechanism for a planetary gear device, wherein the planetary gear is pressed in the axial direction with a constant elastic force. 2. The carrier according to claim 1, comprising a first carrier piece located on one side of the planetary gear in the device axial direction and a second carrier piece located on the other side of the planetary gear, The same number of the planetary gear devices are rotatably supported on the first and second carrier pieces, respectively, and the planetary gears are supported by the first and second carrier pieces when viewed in the circumferential direction. The planetary gears are arranged so that they are alternately located, and the planetary gears supported by the first carrier piece are elastically pressed from one side in the device axial direction by the elastic preloading means. The backlash removing mechanism of the planetary gear device, wherein the planetary gear supported by the second carrier piece is pressed by an elastic force from the opposite side.