JPH09269036A - Planetary gear deceleration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent rotation of a plane bearing with certeinty without using exclusive parts for a revolving shaft of a planet gear, and secure satisfactory lubricancy of the planet gear with a low cost in a deceleration device which has a planetary gear mechanism for decelerating rotation of a main shaft with a specified ratio to transmit a rotor housing. SOLUTION: Flat portions 20 which can be axially extracted are formed for preventing rotation that supports torque generated by meshing repulsion of a planet gear 8b between a revolving shaft 9b of the planet gear 8b and a plane bearing 13. The flat portions 20 are formed by drawing respectively the revolving shaft 9b and the plane bearing 13. A crushed portion 21 is formed on the plane bearing 13 so as to form a gap in respect to the planet gear 8b for storing oil by drawing. The plane bearing 13 is prevented from escaping by means of a thrust ring 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear type speed reducer.

[0002]

2. Description of the Related Art For example, as a speed reducer that integrally houses a hydraulic motor and a planetary gear mechanism, a speed reducer configured as shown in FIG. 8 is conventionally known. A hydraulic motor (not shown) is housed inside the motor housing 1, and the main shaft 2 is spline-fitted to the rotary shaft thereof. A rotor housing 3 is rotatably supported on the outer periphery of the motor housing 1 via angular ball bearings 4.
The three-stage planetary gear mechanism 5 is assembled between the main shaft 2 and the main shaft 2.

As the first stage, a sun gear 6a is formed on the outer periphery of the tip of the main shaft 2, and hollow sun gears 6b, 6c which are freely rotatable on the main shaft 2 are provided at the second and third stages. Planet gears 8a to 8c are interposed between the sun gears 6a to 6c and the ring gears 7a and 7b on the inner circumference of the rotor housing 3, and the planetary gears 8a and 8b have their respective rotation shafts 9a and 9b.
Carriers 10a, 10b for supporting the are provided. A gear 11a that meshes with the second-stage sun gear 6b is formed on the first-stage carrier 10a, and a gear 11b that meshes with the third-stage sun gear 6c is formed on the second-stage carrier 10b.
The planet gear 8c of the stage is supported by the fixed rotation shaft 9c in the motor housing 1 via the carrier 10c.

When the sun gear 6a integral with the main shaft 2 rotates in response to the output rotation of the hydraulic motor, the planet gear 8a of the first stage revolves around the sun gear 6a, and the rotation of the carrier 10a accompanying this rotates the second stage of the carrier 10a. The sun gear 6b rotates. The second stage planet gear 8b revolves around the sun gear 6b, and the third stage sun gear 6c is passed through the carrier 10b.
Tell the rotation. Since the rotation shaft 9c of the planet gear 8c is fixed to the motor housing 1, the planet gear 8c only rotates by receiving the rotation of the sun gear 6c.
b rotates. That is, the spindle 2 accompanying the drive of the hydraulic motor
Rotation causes the rotor housing 3 to decelerate at a predetermined rotation ratio via the three-stage planetary gear mechanism 5.

The rotating shafts 9a-9c are carriers 10a-10.
is fixed to c with pins 12a to 12c, and the plain bearing 1 serves as a bearing for the planet gears 8a to 8c on the outer periphery thereof.
3a to 13c are provided. Plain bearing 13a
13c are fixed to the rotation shaft sides 9a to 9c by pins 14a to 14c, and the sliding surfaces of the planet gears 8a to 8c are formed on the outer periphery thereof. The planet gears 8a to 8c are sandwiched by thrust washers 15a to 15c, and the plain bearing 13
a-14c pins 14a-14c and carriers 10a-1
It is assembled with 0c. The positioning plate 16 restrains the planet gear 8a and the carrier 10a from moving in the axial direction. The center portion of the positioning plate 16 abuts on the projection 17 of the cover 18 that closes the end portion of the rotor housing 3, and the plain bearing 13a is formed on the outer peripheral portion thereof. Locks elastically. It should be noted that passages 19a to 19c for guiding the lubricating oil to the sliding surfaces of the planet gears 8a to 8c are formed on the rotation shafts 9a to 9c by drilling.

[0006]

By the way, the pins 14a to 14c are used as detents for the plain bearings 13a to 13c with respect to the rotation shafts 9a to 9c of the planet gears 8a to 8c.
14c is used, but with this, planet gear 8a-
Since the pins 14a to 14c and the pin holes are required as many as 8c, and the number of parts and the number of assembling steps are increased, there is a problem that the cost is increased.

The present invention has been made in consideration of such problems, and in order to reduce the cost due to the reduction of the number of parts, the plain bearing is properly used without using a dedicated part for the rotating shaft of the planet gear. The purpose is to provide a means to prevent rotation.

[0008]

According to a first aspect of the present invention, there is provided a deceleration comprising a main shaft which rotates upon receiving an output rotation of a motor and a planetary gear mechanism which decelerates the rotation at a predetermined rotation ratio and transmits it to a rotor housing. In the device, a plane bearing that supports the planet gears of the planetary gear mechanism rotatably on its rotation axis is provided, and as a detent that supports the rotation force generated by the meshing reaction force of the planet gears between the rotation axis and the plain bearing, It is formed in a fitting shape other than the circular cross section that can be pulled out in the axial direction.

In the second invention, the fitting shape as the detent in the first invention is formed by subjecting the outer diameter shape of the rotation shaft and the inner diameter shape of the plain bearing to plastic working such as drawing.

In a third aspect of the invention, a crushed portion that provides a gap for oil storage with the inner periphery of the planet gear is formed on a part of the outer periphery of the plain bearing of the first aspect by plastic working such as drawing.

In a fourth aspect of the present invention, a thrust ring that is coupled to the end face of the rotation shaft is provided as a retainer for the planet gear and the plain bearing in the first aspect.

[0012]

According to the first aspect of the present invention, the plain bearing is fixed on the rotation shaft in a fitting condition that allows extraction other than a circular cross section. That is, it is possible to properly prevent the plain bearing from rotating with respect to the rotation shaft without using a dedicated part without impairing the assembling property of the plain bearing to the rotation shaft.

According to the second aspect of the present invention, the fitting shape of the plain bearing as the detent for the rotation shaft is easily formed by plastic working such as drawing.

According to the third aspect of the invention, the sliding surface between the planet gear and the plain bearing is satisfactorily lubricated by the oil accumulated in the gap. Further, the crushed portion forming the gap is easily formed by plastic working such as drawing, and the assembling property between the planet gear and the plain bearing is not impaired.

According to the fourth aspect of the present invention, the thrust ring can properly prevent the planet gear and the plain bearing from coming off.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 2 denotes a main shaft which rotates by receiving output rotation of a hydraulic motor (not shown), and a two-stage planetary gear mechanism 5 is assembled between the main shaft and a rotor housing 3. As the first step, the sun gear 6 is attached to the outer periphery of the tip of the spindle 2.
a is formed, and a hollow sun gear 6b that is freely rotatable on the main shaft 2 is provided in the second stage. Planet gears 8a and 8b are interposed between the sun gears 6a and 6b and the ring gear 7 on the inner circumference of the rotor housing 3, and a carrier 10 that supports a rotation shaft 9a of the planet gear 8a is provided. A gear 11 that meshes with the second stage sun gear 6b is formed on the carrier 10, and the second stage planet gear 8b is supported by a rotation shaft 9b fixed to the motor housing 1. Reference numeral 4 denotes an angular ball bearing that supports the rotor housing on the motor housing in a freely rotatable manner.

The second stage rotating shaft 9b is the motor housing 1
And a plain bearing 13 as a bearing of the planet gear 8b is provided on the outer periphery thereof. As shown in FIGS. 2 to 5, the plain bearing 13 and the rotation shaft 9b have a fitting shape other than a circular cross section that can be extracted in the axial direction as a detent that supports the rotational force generated by the meshing reaction force of the planet gear 8b. It is formed. in this case,
The outer diameter shape of the rotation shaft 9b and the inner diameter shape of the plain bearing 13 are drawn into a cross-sectional shape including a pair of flat portions 20 facing each other at symmetrical positions on the circumference. Also,
The plain bearing 13 has a planet gear 8 on its outer periphery.
b Flat portion 21 forming a gap for oil storage with the inner circumference
Similarly, the (crushed portion) is formed at the symmetrical position on the circumference by drawing.

The plain bearing 13 is fitted to the rotation shaft 9b together with the thrust washer 15, and the planet gear 8b is fitted to the outer periphery of the plain bearing 13. After that, as a retainer for the plain bearing 13 and the planet gear 8b, a thrust ring 22 that traverses these end faces is coupled to the end face of the rotation shaft 9b with a screw 23, so that the planet gear 8
b is rotatably supported on the plain bearing 13,
The thrust ring 22 and the thrust washer 15b properly suppress the axial movements of the planet gear 8b and the plain bearing 13.

Regarding the first stage planet gear 8a,
It is rotatably mounted on a rotation shaft integrally formed with the carrier 10 via a needle bearing 24. Reference numeral 25 denotes a sleeve that protects the outer circumference of the rotation shaft 9a and is firmly fitted to the rotation shaft 9a. A positioning plate 16 is provided to suppress axial movement of the planet gears 8a and the like.
The plate 16 contacts the protrusion 17 of the cover 18 that closes the end of the rotor housing 3 at the center, and fixes the outer periphery of the plate 17 to the rotation shaft 9a with the pin 25 so that the plate 16 rotates integrally with the carrier 10 while thrusting. The movement of the planet gear 8a and the like in the axial direction is suppressed between the washer 15a and the washer 15a.

When the sun gear 6a integral with the main shaft 2 rotates in response to the output rotation of the hydraulic motor, the planet gear 8a of the first stage revolves around the sun gear 6a, and the rotation of the carrier 10 accompanying this rotates the second stage of the carrier 10. The sun gear 6b rotates.
Since the rotation shaft 9b of the planet gear 8b of the second stage is fixed to the motor housing 1, the planet gear 8b only rotates by receiving the rotation of the sun gear 6b, and the ring gear 7 rotates with the rotation thereof. Therefore, the rotor housing 1 is decelerated at a predetermined rotation ratio via the two-stage planetary gear mechanism 5 by the rotation of the main shaft 2 accompanying the driving of the hydraulic motor.

In this case, the plain bearing 13 is fixed between the plain bearing 13 and the rotation shaft 9b in a fitting state which is not circular but has a cross section. That is, the plain bearing 13 can be properly prevented from rotating without using any dedicated parts such as pins. Moreover, because of the fitting shape that can be pulled out in the axial direction,
The assemblability to the rotation shaft 9b is also secured. Since the fitting shape can be easily formed by drawing, the cost for stopping rotation can be reduced. Further, the flat portion 21 on the outer circumference of the plain bearing 13 forms a gap that penetrates in the axial direction between the flat gear 21 and the inner circumference of the planet gear 8b, and the lubricating oil in the rotor housing 3 collects therein. Can lubricate well. Since the flat portion 21 forming the gap can be easily formed by drawing, the cost is more advantageous than the case where the passage is formed by drilling inside the rotation shafts 9a and 9b. The flat portion 21 does not impair the assemblability with the planet gear 8b.

The plain bearing 13 and the rotation shaft 9
As the fitting shape for the detent that can be pulled out in the axial direction with b, the plain bearing 1 as shown in FIGS.
The protrusion 26 may be provided on one of the inner circumference of the shaft 3 and the outer circumference of the rotation shaft 9b, and the engagement groove 27 may be provided on the other. Also for the first stage planet gear 8a, instead of the needle bearing 24, the plain bearing 13
When using, the rotation axis 9a of the plain bearing 13
With the same fitting shape, it is possible to accurately respond to the rotation stopper.

[0023]

According to the first aspect of the present invention, there is provided a speed reducer including a main shaft that rotates upon receiving output rotation of a motor and a planetary gear mechanism that reduces the rotation at a predetermined rotation ratio and transmits it to a rotor housing. , A planet bearing that supports the planet gears of the planetary gear mechanism rotatably on its axis of rotation is provided, and axial directions are used as detents that support the rotational force generated by the meshing reaction force of the planet gears between the axis of rotation and the plane bearing. Since it is formed in a fitting shape other than the circular cross-section that can be pulled out, no special parts such as pins are required to prevent rotation of the plain bearing with respect to the rotation axis, and the cost can be reduced.

According to the second aspect of the invention, the fitting shape for preventing rotation in the first aspect of the invention is formed by subjecting the outer diameter shape of the rotation shaft and the inner diameter shape of the plain bearing to plastic working such as drawing. An accurate detent can be easily realized at low cost.

According to the third aspect of the present invention, a crushed portion that forms an oil reservoir gap between the plain bearing of the first aspect and the inner periphery of the planet gear is formed by plastic working such as drawing. Therefore, good lubricity of the planet gears can be easily secured at low cost.

According to the fourth aspect of the present invention, since the thrust ring coupled to the end face of the rotation shaft is provided as a retainer for the planet gear and the plain bearing in the first aspect, the planet gear and the plain bearing are provided on the rotation shaft. With this, you can get a proper stopper.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is also an enlarged view of a circular area A.

FIG. 3 is a view similarly seen from the arrow B.

FIG. 4 is a front view a, a plan view b, and a side view c of the plain bearing.

FIG. 5 is a front view a, a plan view b, and a side view c of the rotation shaft.
It is.

FIG. 6 is a front view a and a plan view b of another plain bearing.
And a side view c.

FIG. 7 is a front view a, a plan view b, and a side view c of the rotation shaft.
It is.

FIG. 8 is a sectional view illustrating a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 motor housing 2 main shaft 3 rotor housing 5 planetary gear mechanism 6a, 6b sun gear 7 ring gear 8a, 8b planet gear 9a, 9b rotating shaft 10 carrier 11 gear 13 plain bearing 15a, 15b thrust washer 16 positioning plate 17 protrusion 20 flattening portion 21 Part 22 Thrust ring 23 Screw

Claims (4)

[Claims] 1. A planetary gear mechanism for a planetary gear mechanism, comprising: a main shaft that rotates in response to an output rotation of a motor; and a planetary gear mechanism that reduces the rotation at a predetermined rotation ratio and transmits the planetary gear mechanism to a rotor housing. A plain bearing that supports rotation on the rotation shaft is provided, and as a detent that supports the rotation force generated by the meshing reaction force of the planet gears between the rotation shaft and the plain bearing, a non-circular cross section other than the axially extractable circular cross section is used. A planetary gear type speed reducer characterized by being formed in a fitting shape. 2. The planetary gear type according to claim 1, wherein the fitting shape as the detent is formed by plastically processing the outer diameter shape of the rotation shaft and the inner diameter shape of the plain bearing by drawing or the like. Reduction gear. 3. The plain bearing according to claim 1, wherein a crushed portion forming a gap for oil storage with the inner circumference of the planet gear is formed on a part of the outer circumference of the plain bearing by plastic working such as drawing. Planetary gear type speed reducer. 4. The planetary gear type speed reducer according to claim 1, wherein a thrust ring coupled to an end face of the rotation shaft is provided as a retainer for the planet gear and the plain bearing.