JPH0627867Y2 - Output shaft coupling device for planetary gearbox - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an output shaft coupling device for a planetary gear speed reducer, which prevents runout of the output shaft and reduces noise and vibration.

(Prior Art) Various speed reducers using an internally meshing planetary gear mechanism have been proposed. Among these reduction gears, the internal gear has an arcuate tooth profile consisting of pins or a combination of pins and rollers, and the external gear has a trochoidal profile consisting of epitrochoid parallel curves. A planet in which the pin and the inner roller are loosely fitted, and the external gear is oscillated by the rotation of the eccentric body fitted to the external gear, and the internal and external gears are internally meshed to reduce the input rotation and output. The gear reducer is well known as "cyclo reducer" (registered trademark).
The "cyclo reduction gear" is capable of transmitting a large torque and has a large reduction ratio, so that it is used as various reduction gears.

An example of a known "cyclo speed reducer" will be described below with reference to FIG.

FIG. 3 is a sectional view showing an example of a known planetary gear reducer.

In this example, the rotation of the input rotary shaft 1 is taken out as the decelerated rotation of the output shaft 2 and is taken out.
Can be fixed, and decelerated rotation can be taken out from the internal gear.

A hollow eccentric body shaft 3 is fixed to the input rotary shaft 1 via a key (not shown) and a key groove 4, and the eccentric body shaft 3 is provided with _two eccentric bodies 3 ₁ , 3 ₂ . . External gear 5
₁ and 5 ₂ are fitted to the individual eccentric bodies 3 ₁ and 3 ₂ via rollers 6. The external gears 5 ₁ and 5 ₂ have external teeth 7 having a trochoidal tooth profile on the outer circumference thereof. Internal gear 8
Also serves as the outer casing, and the internal gear 8
Is fixed in this example. The internal gear 8 is the external gear 5
_It has an arcuate tooth profile consisting of an outer pin 9 that meshes with ₁ and 5 ₂ internally. The outer pin 9 may be provided with an outer roller. Inner pin 11 is loosely fitted in the external gear 5 _1, 5 ₂ and the inner pin holes 10 are formed in the inner pin holes 10. An inner roller 12 is loosely fitted to the outer periphery of the inner pin 11, and one end of the inner pin 11 is tightly fitted to the inner pin holding flange 13. Here, the inner roller 12 can be omitted. The inner pin holding flange 13 is formed integrally with the output shaft 2 in this example.

Casings 14 ₁ and 14 ₂ are provided with the internal gear 8 interposed therebetween to support the input shaft 1, so that two input bearings 15 ₁ are provided.
15 ₂ are provided on both sides sandwiching the external gear 5 ₁ , 5 ₂ . Input bearing 15 ₁ the outer periphery of the input shaft 1 and the casing 14
Provided between _one input bearing 15 ₂ is provided between the outer and the inner pin holding flange 13 formed recesses 13 ₁ of the inner surface of the input shaft 1. In order to support the output shaft 2,
Two output bearings 16 ₁ and 16 ₂ are provided between the outer circumference of the output shaft 2 and the casing 14 ₂ .

In this known planetary gear reducer, one rotation of the input shaft 1 becomes one rotation of the eccentric bodies 3 ₁ , 3 ₂ , but the external gears 5 ₁ , 5 ₂
Since its rotation is restricted by the inner pin hole 10 and the inner pin 11, the external gears 5 ₁ and 5 ₂ are oscillated and rotated with the oscillating radius e. Therefore, when the difference between the number of teeth of the external gears 5 ₁ and 5 _{2 and} the number of external pins 9 (the number of teeth of the internal gear 8) is 1, the external gear 5 is rotated by one rotation of the input shaft 1. _1, 5 and ₂ of the external teeth 7 and the outer pins 9 is the inner teeth of the internal gear 8 is meshed displaced by one tooth (shifted). Therefore, one rotation of the input shaft 1 is reduced to 1 / the number of teeth of the external gears 5 ₁ and 5 ₂ , and the rotation is transmitted to the output shaft 2 via the inner pin 11.

(Problems to be solved by the invention) However, the above planetary gear speed reducer has the following problems.

Looking at the load acting on the input shaft 1 and the output shaft 2 with reference to FIG. 4, the rotational load W that the output shaft 2 receives from the input shaft 1
₁ acts at the end position of the input shaft 15 _2, as shown in FIG. The load W ₂ that the output shaft 2 receives from an external gear (not shown) acts on the inner pin 11 as shown. Furthermore, the load W ₃ of the input shaft 1 receives from the external gear is acting on the input shaft 1 as shown.

The loads W ₁ and W ₂ acting on the output shaft 2 are output bearings 16 ₁ ,
Since it is located closer to the input shaft 1 than 16 ₂ , the output shaft 2 is cantilevered to receive the loads W ₁ and W ₂ , and the moment thereof causes only the angle α with respect to the normal shaft center O ₁ . I will lean.

Further, the load W ₃ acting on the input shaft 1 is combined with the inclination of the output shaft 2, and the moment of the load W ₃ causes the input shaft 1 to move to the normal axis O.
_The angle β is inclined with respect to ₁ .

For this reason, the input shaft 1 and the output shaft 2 rotate while shifting their axes, which causes noise and vibration.

Further, as shown in FIG. 5, even when a radial load F is applied to the output shaft 2 from the outside, the output shaft 2 is inclined by α ′ with respect to the normal shaft center O ₁ as described above, Input shaft 1
Is inclined with respect to the normal axis O ₁ by β ′, which causes noise and vibration.

The inclination of the output shaft 2 and the input shaft 1 is due to the output shaft 2 being directly connected to the inner pin holding flange 13.

On the other hand, in the planetary gear reducer, an Oldham coupling is provided between the external gears adjacent to each other in order to omit the inner pin, and the Oldham coupling is also used for the connection between the external gear and the output shaft. A planetary gear mechanism having a structure is conventionally known as shown in FIG.

That is, referring to FIG. 6, the rotation of the input shaft 41 is controlled by the output shaft 4
Upon transferring to 2, the external gears ₄₄ 1, 44 ₂ is swung rotated by the rotation of the eccentric member 43 which is provided to the input shaft 41. External gear 44 ₂ is restricted to rotate by the internal gear 45, the oscillatingly rotating. Further, the external gear 44 ₁ is also restricts rotation by the internal gear 45 in the same manner, the oscillatingly rotating.
Rocking rotation of the external gear 44 ₁ is transmitted to the external gear 44 ₂ via the Oldham coupling 46 _1, rocking rotation of the external gear 44 ₂ is transmitted to the output shaft 42 via the Oldham coupling 46 ₂ .

The planetary gear mechanism using the Oldham couplings 46 ₁ and 46 ₂ instead of the inner pins in order to omit the inner pins has a structure in which the deviation of the shaft center of the output shaft 42 is absorbed as a result. essentially a inner pin omitted purpose, Oldham coupling 46 _1, 46 ₂ is only an alternative to the inner pin.

Moreover, since the planetary gear mechanism using the Oldham's coupling 46 _1, 46 _2, go adding to multiple sequence was external gear 44 _1, 44 of the _second rotary torque sequentially output shaft 42 side external gear, most the external gear 44 _{and second} position close to the output shaft becomes that excessive torque acts, there is a limit to the transmitted torque. This means that although the reason for originally providing a plurality of external gears is to reduce the transmission torque per one, the transmission torque increases as a result in the planetary gear mechanism using the Oldham coupling. Therefore, the reason for providing a plurality of external gears becomes meaningless.

Further, in the planetary gear mechanism using the Oldham coupling, since the Oldham coupling is used instead of the inner pin, reciprocating sliding twice the swing radius occurs at the Oldham portion. Therefore, the progress of wear is fast, and there are problems in terms of durability and strength.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an output shaft coupling device in a planetary gear increasing / decreasing machine which eliminates the inclination of the output shaft to reduce the noise and vibration.

(Means for Solving Problems) A feature of the present invention is that an input shaft, an eccentric body provided on the input shaft, and an external gear fitted to the eccentric body,
An internal gear having an external pin that internally meshes with the external gear;
An internal pin hole formed in the external gear, an internal pin loosely fitted in the internal pin hole, an internal pin holding ring in which the internal pin 31 is tightly fitted, an internal pin holding ring and an output shaft. It consists of a shaft coupling that absorbs the deviation of the connecting shaft center, and is intended to reduce or eliminate the inclination of the output shaft and the input shaft.

(Example) Hereinafter, a detailed description will be given with reference to the drawings.

1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a contact state between the inner pin retaining ring and the outer pin of FIG.

In this embodiment, the rotation of the input shaft 21 is taken out as the deceleration or acceleration of the output shaft 22.

A hollow eccentric body shaft 23 is inserted into the input shaft 21, and the eccentric body shaft 23 is fixed to the input shaft 21 by a key (not shown) and a key groove 24. This eccentric body shaft 23 has 2
Individual eccentric bodies 23 ₁ and 23 ₂ are formed. Eccentric body 2
External gears 25 ₁ and 25 ₂ are fitted to 3 ₁ and 23 ₂ via bearings 26. The external gears 25 ₁ and 25 ₂ have external teeth 27 having a trochoidal tooth profile on their outer circumferences. The internal gear 28 is integrally formed with the casing, and the internal gear 28 has an arcuate tooth profile including an external pin 29 that is internally meshed with the external gears 25 ₁ and 25 ₂ . An outer roller 29 ₁ is loosely fitted to the outer pin 29. Inner pin holes 30 are formed in the external gears 25 ₁ and 25 ₂ , and inner pins 31 are loosely fitted in the inner pin holes 30. An inner roller 32 is loosely fitted on the outer periphery of the inner pin 31, and the inner pin 31 has both ends thereof at the inner pin holding ring 3
3 ₁ and 3 3 ₂ are closely fitted. Here, the inner roller 12
Can be omitted. Inner pin retaining ring 3
3 ₁ and 3 3 ₂ are provided on both sides of the external gear 25 ₁ and 25 ₂ with the external gears 25 ₁ and 25 ₂ sandwiched therebetween, and the outer periphery thereof is in contact with the outer pin 29 and is rotatable. This acts as a radial bearing. Also, the inner pin holding rings 33 ₁ , 3
3 ₂ the end face of the outer roller 29 ₁ is in contact with, thereby acting as a thrust direction of the bearing.

It is a feature of the present invention is not the one of the inner pin retaining ring 33 ₂ and the output shaft 22 is directly connected, is in place and the flexible coupling structure capable of absorbing misalignment of the axis.

That is, Oldham coupling 34 is provided between the inner pin retaining ring 33 ₂ and the flange 22 ₁ of the output shaft 22.
The Oldham coupling 34 is intended to absorb the displacement of the axis of the output shaft 22 and the inner pin retaining ring 33 _2.

Bearings 35 ₁ and 35 ₂ are provided between the input shaft 21 and the inner pin retaining rings 33 ₁ and 33 ₂ to support the input shaft 21, and an output shaft 22 and a casing 36 are provided to support the output shaft 22. bearing ₃₇ 1, 37 ₂ is provided between the.

Since the present invention is configured as described above, even if the output shaft and other components are misaligned due to deformation due to load, the connection between the output shaft and the inner pin support ring does not cause misalignment. Since they are connected by the absorbing joint, there is no displacement of the output shaft.

The present invention is not limited to the above embodiment, but can be applied to various types of internally meshing planetary gear mechanisms.
These applications are also included in the present invention.

The joint mechanism for absorbing the deviation in the present invention includes various known joints such as spline joints in addition to the Oldham joint.

(Effects of the Invention) The effects of the present invention configured as described above are as follows.

Even if the shaft center of the planetary gear mechanism part such as the output shaft and the input shaft, external gear, inner pin, etc. is displaced due to the deformation due to the transmission load, it can be absorbed by the Oldham coupling, so there is little noise or vibration. .

According to the structure in which the inner pin retaining rings are provided on both sides of the outer gear, and the outer periphery of the inner pin retaining ring is in contact with the outer roller to be rotatable, the outer gear and the inner pin are further prevented from being deformed. Greatly prevents noise and vibration.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
The front view showing the inner pin retaining ring and the outer pin portion in the figure,
FIG. 4 is a cross-sectional view showing a conventionally known planetary gear reducer, FIG. 4 is a diagram for explaining an action point of a rotation transmission load and inclination of an output shaft and an input shaft of a conventionally known planetary gear reducer, and FIG. The figure which shows the inclination of the output shaft and the input shaft by the action of the external force of a known planetary gear reducer, and FIG. 6 is a partially broken front view of the planetary gear reducer using a conventionally known Oldham coupling. 21: input shaft, 23 ₁ , 23 ₂ , eccentric body 25 ₁ , 25 ₂ : external gear, 26: bearing 28: internal gear, 29: outer pin, 29 ₁ : outer roller 30: inner pin hole, 31 : the inner pin, 32: inner roller 33 _1, 33 _2: the inner pin retaining rings, 34: fitting

Claims (3)

[Scope of utility model registration request] 1. An input shaft, an eccentric body provided on the input shaft, an external gear fitted to the eccentric body, and an internal gear having an external pin internally meshing with the external gear. An inner pin hole formed in the external gear, an inner pin loosely fitted in the inner pin hole, an inner pin holding ring in which the inner pin 31 is tightly fitted, an inner pin holding ring and an output shaft An output shaft coupling device in a planetary gear increasing / decreasing machine, comprising: 2. A utility model registration claim according to claim 1, characterized in that inner pin retaining rings are provided on both sides of the external gear, and the inner pins are supported by the inner pin retaining rings. Output shaft coupling device for the planetary gear speed reducer. 3. The utility model registration claim, wherein the outer circumference of the inner pin retaining ring is in contact with the outer pin and is rotatable. Coupling device.