JPH0510400A - Reduction gear - Google Patents

Abstract

PURPOSE:To obtain a reduction gear which is simple in structure, large in reduction ratio, small in thickness large in transmission torque capacity and large in rigidity. CONSTITUTION:An eccentric rotary plate 5 having a first cycloidal groove 6 on its both sides is eccentrically driven with an eccentric cam 4 of an input shaft 2. On both sides of the eccentric rotary plate 5, there is disposed a fixed member 8 having a second cycloidal groove 9 on its surface. A common ball 7 is fitted in the first cycloidal groove 6 and the second cycloidal groove 9. An output rotary body 3 is disposed on the opposite face of the eccentric rotary plate 5 on the side of the inner periphery of the fixed members 8. The output rotary body 3 is rotation driven with the eccentric rotary plate 5 via an eccentricity absorbing mechanism 10 for absorbing the eccentricity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reducer for decelerating and transmitting transmitted rotary power by using an eccentric motion and a cycloid groove.

[0002]

2. Description of the Related Art An example of this type of speed reducer is shown in FIG.
The decelerator 101 is provided with an eccentric rotary plate 103 having a first cycloidal groove 102 formed on one side thereof, and is arranged to face the eccentric rotary plate 103, and a second cycloidal groove 104 is provided on one side on the side where the eccentric rotary plate 103 is arranged. Formed fixed member 105 and eccentric rotating plate
First and second cycloidal grooves 10 of 103 and fixing member 105
2 and a ball 106 arranged over 104. When the eccentric rotary plate 103 is eccentrically driven by the input rotary body 107, the eccentric rotary plate 103 is decelerated and driven,
The output rotating body 108 arranged opposite to the 103 is an eccentric absorption mechanism.
It rotates integrally with the eccentric rotary plate 103 via 109.

[0003]

The conventional speed reducer 101 is
Since the first cycloidal groove 102 on one side of the eccentric rotating plate 103 and the second cycloidal groove 104 on one side of the fixing member 105 have a structure in which power is transmitted through the balls 106, the eccentric rotating plate 103 and the fixing member are arranged. Each of 105 had a problem of low rigidity due to deformation such as warping.

Further, since torque is transmitted by one surface of the eccentric rotary plate 103 and one surface of the fixed member 105, there is a problem that the transmission torque capacity is low.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a speed reducer having a high rigidity and a large transmission torque capacity.

[0006]

SUMMARY OF THE INVENTION A speed reducer according to the present invention includes an eccentric rotating plate having first cycloid grooves of the same shape on both sides, an input rotating body for eccentrically driving the eccentric rotating plate, and both sides of the eccentric rotating plate. A plurality of balls arranged in each of the first cycloid grooves, and a fixing member that sandwiches the eccentric rotary plate from both sides via these balls and that has a second cycloid groove in which the balls are arranged, The technical means including an output rotating body to which the rotational power of the eccentric rotary plate is transmitted via an eccentric absorption mechanism that absorbs the eccentricity of the eccentric rotary plate is adopted.

[0007]

The speed reducer having the above structure is
An eccentric rotary plate is sandwiched by fixed members via balls arranged on both sides.

As a result, the torque transmission capacity is doubled as compared with the prior art in which torque transmission is one-sided.

Further, since the transmission torque is applied to both surfaces of the eccentric rotary plate, the fixed member and the eccentric rotary plate do not bend such as warp, and the rigidity is higher than in the conventional case.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a speed reducer of the present invention will be described based on the embodiments shown in the drawings.

[Structure of First Embodiment] FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a side sectional view of a speed reducer, and FIG. 2 is a line AA of FIG. FIG.

The speed reducer 1 shown in this embodiment is used for an arm part of an industrial robot, etc., and decelerates the rotational power transmitted to the input shaft 2 (input rotary body) to output the rotary body 3.
Is to be transmitted to.

Specifically, the rotational power transmitted to the input shaft 2 drives the eccentric rotary plate 5 eccentrically by the eccentric cam 4 provided on the input shaft 2. The eccentric rotary plate 5 has a first cycloid groove 6 having the same epicycloidal curve on both sides.
And is related to the fixing member 8 via the plurality of balls 7 arranged in the first cycloid groove 6. Fixing member 8
Are provided so that the outer periphery of the eccentric rotary plate 5 is sandwiched by the balls 7 with the outer peripheral surface of the eccentric rotary plate 5 interposed therebetween.
A second cycloid groove 9 having a hypocycloid curve is provided on each surface of the fixed member 8 facing the eccentric rotary plate 5. This second cycloid groove 9 is
A ball 7 fitted in the first cycloid groove 6 of the eccentric rotary plate 5 is arranged, and the fixed member 8 and the eccentric rotary plate 5 are connected via the ball 7. The second cycloid groove 9
Of the first cycloid groove 6 has two more waves,
Alternatively, two waves are provided less.

On both sides of the inner circumference of the eccentric rotary plate 5, output rotary bodies 3 connected to an output shaft (not shown) are arranged. The output rotary body 3 is connected to the eccentric rotary plate 5 via an eccentric absorption mechanism 10 that absorbs the eccentricity of the eccentric rotary plate 5, and the rotational power of the eccentric rotary plate 5 is transmitted to the output rotary body 3. The eccentricity absorption mechanism 10 of the present embodiment includes a plurality of balls 11 arranged between the eccentric rotary plate 5 and the output rotary body 3, and the eccentric rotary plate 5 and the output rotary body 3 for arranging the balls 11. It is provided with a drive annular groove 12 and a driven annular groove 13 which are provided in an annular shape. The pitch of the deepest portion of each annular groove 12, 13 is set to 1/2 of the eccentric amount. As a modified example, when the ball 7 is fitted into one of the eccentric rotary plate 5 or the output rotary body 3 so as not to move, the other of the output rotary body 3 or the eccentric rotary plate 5 fitted to the ball 7 is fitted. The pitch of the deepest part of the annular groove provided in is provided with an eccentric amount.

The input shaft 2 is rotatably supported on the inner circumference of the output rotary member 3 via a bearing 14, and the eccentric rotary plate 5 is provided.
Is rotatably supported on the outer circumference of the eccentric cam 4 via a bearing 15, and the output rotor 3 is rotatably supported on the inner circumference of the fixed member 8 via a bearing 16. The fixing member 8 is fixed to a part of an industrial robot (not shown). In the drawings, a ball bearing is shown as an example of the bearing, but other rolling bearings such as roller bearings or slide bearings may be used.

[Operation of Embodiment] Next, the operation of the above embodiment will be briefly described. Input shaft 2 depending on the output of the motor
Is rotationally driven, the eccentric cam 4 eccentrically drives the eccentric rotary plate 5 by the rotational power transmitted to the input shaft 2. Since the eccentric rotary plate 5 is engaged with the second cycloid groove 9 of the fixed member 8 via the balls 7 arranged in the first cycloid grooves 6 on both sides, when the eccentric rotary plate 5 performs one cycle of eccentric motion. , Each ball 7 moves one wave in the first cycloid groove 6 and moves one wave in the second cycloid groove 9.

Here, the center of the first cycloid groove 6 (the eccentric rotary plate 5) is at the center of the second cycloid groove 9 (fixing member 8).
It is offset from the center of by the amount of eccentricity. Thereby, the angle of one wave of the second cycloid groove 9 at the center of the eccentric rotary plate 5 becomes the same as the angle of one wave of the first cycloid groove 6. For this reason, when the input shaft 2 rotates once and the eccentric rotary plate 5 performs one cycle of eccentric motion, the eccentric rotary plate 5 moves relative to the fixed member 8 in the first cycloid groove 6.
It rotates twice the angle of the wave. Then, the output rotating body 3 is
Since the input shaft 2 rotates once and the eccentric rotary plate 5 makes one cycle of eccentric motion because it rotates integrally with the eccentric rotary plate 5 through the eccentric absorption air holes 10, the output rotary body 3 also moves with the eccentric rotary plate 5. , The first cycloid groove 6 is rotated twice the angle of one wave. That is, the reduction ratio is 2 / N, where N is the wave number of the first cycloid groove 6. Then, for example, when the wave number of the first cycloid groove 6 is 18 and the wave number of the second cycloid groove 9 is 20, the speed reducer 1 of this embodiment is
The reduction ratio of is 2/18 = 1/9.

[Effects of the Embodiment] The speed reducer 1 of the present embodiment is
As shown in the above-described operation, the thickness can be the thickness of the fixed member 8 or the output rotary body 3 that sandwiches the eccentric rotary plate 5 while ensuring a large reduction ratio. Further, in the speed reducer 1 of the present embodiment, the eccentric rotary plate 5 is sandwiched between the fixed members 8 via the balls 7 arranged on both sides, so that the transmission torque capacity is lower than that of the conventional single-sided speed reducer. Doubles. further,
In the speed reducer 1 of the present embodiment, the transmission torque is applied to both surfaces of the eccentric rotary plate 5, so that the fixed member 8 and the eccentric rotary plate 5 do not bend such as warp. Higher than a single-sided speed reducer.

That is, the speed reducer 1 of the present embodiment is a simple mechanism, has a large reduction ratio, is very thin, can achieve a large transmission torque capacity, and realizes high rigidity.

[Second Embodiment] FIGS. 3 and 4 show a second embodiment. FIG. 3 is a side sectional view of the speed reducer 1, and FIG. 4 is a sectional view taken along the line BB of FIG. Show.

In this embodiment, the output rotators 3 arranged on both sides of the eccentric rotary plate 5 are integrated by a connecting member 17, and the eccentric absorption mechanism 10 is changed. The eccentricity absorption mechanism 10 of the present embodiment includes a cylindrical pin 18 fixed to the eccentric rotary plate 5 so as not to rotate or rotatably, and a driven hole 19 in which the pin 18 formed in the output rotary body 3 is arranged. Consists of.
The driven hole 19 is provided with a large amount of eccentricity so that the pin 18 can escape the eccentricity of the eccentric rotary plate 5. In addition, the insertion hole 20 formed in the eccentric rotary plate 5 in which the connecting member 17 is arranged.
Are provided in such a size that they do not interfere with each other even if the eccentric rotary plate 5 moves eccentrically.

Since the pin 18 comes into contact with the eccentric rotary plate 5 and the output rotary body 3 (inner surface of the driven hole 19) on both sides of the pin 18 at three points, the pin 18 is unlikely to be bent, so that the pin 18 has high rigidity. Can be kept. When the pin 18 is non-rotatably provided on the eccentric rotary plate 5, the pin 18 and the output rotary body 3 are in sliding contact. Further, when the pin 18 is rotatably provided on the eccentric rotary plate 5, the pin 18 and the output rotary body 3 are in rolling contact, and the pin 18 and the eccentric rotary plate 5 are in sliding contact.

[Third Embodiment] FIGS. 5 and 6 show a third embodiment. FIG. 5 is a side sectional view of the speed reducer 1, and FIG. 6 is a sectional view taken along the line CC of FIG. Show.

This embodiment is based on the eccentricity absorption mechanism 10 of the second embodiment.
Is partly modified. The pin 18 of this embodiment is inserted into both the drive hole 21 provided in the eccentric rotary plate 5 and the driven hole 19 provided in the output rotary body 3, and the drive hole
The distance between the pin 21 and the driven hole 19 is 1/2 of the eccentric amount of the eccentric rotary plate 5 so that the eccentricity of the eccentric rotary plate 5 is released.

In this embodiment, the pin 18, the eccentric rotary plate 5, the pin
Each of the 18 and the output rotary body 3 is in rolling contact, and the power transmission efficiency is improved as compared with the second embodiment.

[Fourth Embodiment] FIGS. 7 and 8 show a fourth embodiment. FIG. 7 is a side sectional view of the speed reducer 1, and FIG. 8 is a sectional view taken along line DD of FIG. Show.

Also in this embodiment, the eccentricity absorbing mechanism 10 of the second embodiment is used.
Is partly modified. The pin 18 of this embodiment is non-rotatably or rotatably fixed to the output rotary body 3, and the eccentric rotary plate 5 has a drive hole 21 in which the pin 18 is arranged. The inner diameter of the drive hole 21 is provided so that the pin 18 can escape the eccentricity of the eccentric rotary plate 5.

In this embodiment, the eccentric rotary plate 5 is attached by the pin 18.
Since the output rotating bodies 3 on both sides of the above are connected, the connecting member 17 shown in the second embodiment is not necessary, and the pressing force applied to each pin 18 is dispersed, and the pin 18 and the driving hole 21, and the pin 18 and the output rotation. Body 3
Each friction is suppressed and durability is improved, and the output rotors 3 on both sides of the eccentric rotary plate 5 are also firmly connected.

[Fifth Embodiment] FIGS. 9 and 10 show a fifth embodiment. FIG. 9 is a side sectional view of the speed reducer 1, and FIG. 10 is a sectional view taken along the line EE of FIG. Show.

This embodiment is a modification of the fourth embodiment, and the pin
A metal bearing 22 is arranged around 18 to absorb the eccentricity and reduce the frictional resistance with the drive hole 21 in which the pin 18 is arranged. It should be noted that, not limited to this embodiment, it is possible to dispose a member such as a metal bearing that reduces frictional resistance, at every portion that comes into contact with the pin 18.

[Sixth Embodiment] FIGS. 11 and 12 show a sixth embodiment. FIG. 11 is a side sectional view of the speed reducer 1, and FIG. 12 is a sectional view taken along line FF of FIG. Show.

In this embodiment, the output rotary member 3 is provided only on one side of the eccentric rotary plate 5.

[Seventh Embodiment] FIGS. 13 and 14 show a seventh embodiment. FIG. 13 is a side sectional view of the speed reducer 1, and FIG. 14 is a sectional view taken along the line GG of FIG. Show.

In this embodiment, a well-known pan lid type Oldham coupling is used for the eccentric absorption mechanism 10. That is, the eccentric absorption plate 23 is arranged between the eccentric rotary plate 5 and the output rotary body 3, and the eccentric rotary plate 5 is movable in the radial direction of the eccentric rotary plate 5 and is eccentric. And the eccentric rotary plate 5 are attached to the output rotary body 3 so as to rotate together with the output rotary body 3.
Some of them are fitted in such a manner that they can move in the radial direction deviated by 0 ° and rotate integrally with the output rotary body 3.

[0035]

[Modification] An example has been shown in which the cycloid groove of the eccentric rotary plate 5 is an epicycloid curve and the second cycloid groove 9 is a hypocycloid curve, but they may be provided in reverse.

The balls 7 arranged in the cycloid groove may be held by a retainer.

Although the example in which the speed reducer 1 is applied to an industrial robot has been shown, it may be used for other purposes as long as the rotational power is decelerated and used.

[Brief description of drawings]

FIG. 1 is a side sectional view of a speed reducer according to a first embodiment.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a side sectional view of a speed reducer according to a second embodiment.

4 is a cross-sectional view taken along the line BB of FIG.

FIG. 5 is a side sectional view of a speed reducer according to a third embodiment.

6 is a sectional view taken along the line CC of FIG.

FIG. 7 is a side sectional view of a speed reducer according to a fourth embodiment.

8 is a sectional view taken along the line DD of FIG.

FIG. 9 is a side sectional view of a speed reducer according to a fifth embodiment.

10 is a cross-sectional view taken along the line EE of FIG.

FIG. 11 is a side sectional view of a speed reducer according to a sixth embodiment.

12 is a cross-sectional view taken along the line FF of FIG.

FIG. 13 is a side sectional view of a speed reducer according to a seventh embodiment.

14 is a cross-sectional view taken along the line GG of FIG.

FIG. 15 is a side sectional view of a conventional speed reducer.

[Explanation of symbols]

 1 Reduction Gear 2 Input Shaft (Input Rotating Body) 3 Output Rotating Body 5 Eccentric Rotating Plate 6 First Cycloid Groove 7 Ball 8 Fixing Member 9 Second Cycloid Groove 10 Eccentric Absorption Mechanism

Claims (1)

Claims: 1. An eccentric rotating plate having first cycloid grooves of the same shape on both sides, (b) an input rotating body for eccentrically driving the eccentric rotating plate, and (c) the eccentric. A plurality of balls arranged in each of the first cycloid grooves on both sides of the rotary plate, and (d) a second cycloid groove in which the eccentric rotary plate is sandwiched from both sides by these balls and the balls are arranged. And a (e) an output rotary body to which the rotational power of the eccentric rotary plate is transmitted via an eccentric absorption mechanism that absorbs the eccentricity of the eccentric rotary plate.