JPH0756320B2 - Angle Backlash Removal Device in Planetary Gear Mechanism - Google Patents

Description

The present invention relates to an angular backlash in a planetary gear mechanism in which an internal gear having an arcuate tooth profile is meshed with an external gear having an arcuate tooth profile or a trochoidal tooth profile. Related to the removal device.

(Prior Art) In a gear transmission mechanism, there is play or play between gears that mesh with each other or in the means for attaching to a shaft, etc., and when moving from normal rotation to reverse rotation, reverse rotation on the drive side immediately appears as reverse rotation on the driven side. Absent.

Therefore, in the internally meshing planetary gear mechanism,
As seen in Japanese Patent Publication No. 55 or Japanese Utility Model Publication No. 59-3048, a plurality of meshes are made in parallel to increase transmission torque, maintain strength, maintain balance, etc. In the transmission mechanism, the play and rattling at the individual meshing parts interfere with each other and become smaller, but the force is supposed to be transmitted at each meshing part, so even in this product, play and rattling at the time of forward rotation and reverse rotation are performed. Occurs.

The above play and backlash are relative when there are a plurality of meshing portions, and this relative play and backlash will be referred to as angular backlash hereinafter.

An example of a conventionally known planetary gear mechanism will be described below with reference to FIGS. 3 and 4.

A pinion 2 is provided at the end of the input shaft 1 so that the input shaft 1
Is meshed with three transmission gears 3 provided at equal angles around the. The transmission gear 3 is attached to the eccentric body shaft and is rotatable. The eccentric body shaft 4 is axially supported by bearings 5 ₁ and 5 ₂ , and two eccentric bodies 6 ₁ and 6 ₂ are provided in the middle thereof. Eccentric bodies 6 _1, 6 ₂ are disposed 180 degrees transfer is staggered each other, each of the eccentric bodies 6 _1, 6 ₂ external gears _81, 82 having external teeth 7 via an eccentric bearing 9 I support you. That is, as can be seen from FIGS. 3 and 4, the eccentric bodies 6 ₁ and 6 _{2 of} the three eccentric body shafts 4 penetrate the external gears 8 ₁ and 8 ₂ , respectively, and the eccentric body bearing 9 is used to form the external teeth. It supports the gears 8 ₁ and 8 ₂ . The outer teeth 7 have an arcuate or trochoidal tooth profile.

The internal gear 10 has internal teeth composed of an external pin 11, and the internal gear 10 also serves as an outer case.

The external gears 8 ₁ and 8 ₂ have an inner peripheral surface 12 formed of a curve,
The support block 13 is inserted in this. A carrier 14 is provided at an end of the support block 13, and the carrier 14 is fixed to the support block 13 by pins 15 and bolts 16.
Bearings 17 ₁ and 17 ₂ are provided between the carrier 14 and the internal gear 10 and between the support block 13 and the internal gear 10 to rotatably support the internal gear 10. The rotation of the internal gear 10 is taken out from the rotation take-out section 18.

The operation of the known planetary gear mechanism described above is as follows.

The rotation of the input shaft 1 is transmitted to the transmission gear 3 via the pinion 2. The rotation speeds of the transmission gears 3 are reduced by the gear ratio of each other. The transmission gear 3 rotates the eccentric body shaft 4. Since the center O _{2 of} the external gears 8 ₁ and 8 ₂ provided on the eccentric body shaft 4 is eccentric by the rotation center O ₁ of the input shaft ₁ and e, the external gear 8 ₁ , 8 ₂ rotate _once around O ₁ , and as a result, the meshing between the outer teeth 7 and the inner teeth composed of the outer pins 11 shifts by one tooth to make a planetary gear motion.

As described above, the gear transmission mechanism has an angular backlash, and the planetary gear mechanism shown in FIGS. 3 and 4 is no exception.

(Problems to be Solved by the Invention) The presence of such angular backlash causes a decrease in accuracy when the transmission mechanism is used as a control device, and also results in a reduction in durability of the transmission device due to impact. .

In order to remove and reduce the above angle backlash, it was necessary to increase the machining accuracy of the parts and to waste time in selecting and combining the parts, but even with this, it is difficult to remove the sufficient angle backlash, resulting in Had to be expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate or reduce angular backlash in a planetary gear mechanism of this type with a simple attachment means.

(Means for Solving Problems) A feature of the present invention is to provide a pinion provided on an input shaft, a plurality of transmission gears meshing with the pinion, and an eccentric body shaft rotated by the transmission gear. A planetary gear mechanism configured to perform acceleration and deceleration, which comprises an external gear that is held by an eccentric body provided on the eccentric body shaft via an eccentric body bearing, and an internal gear that meshes with the external gear. A plurality of combinations of the external gear and the internal gear held by the shaft are provided in the axial direction of the eccentric body, and at least two sets of the combination of the external gear and the internal gear are provided in one of the plurality of combinations. The eccentric body bearing hole formed in the external gear is shifted in the forward direction by half the angular backlash, and the eccentric bearing formed in the other external gear is shifted in the reverse direction by half the angular backlash. Installed in front Either one of the pinion or the transmission gear is divided into two or two in the axial direction, and one of the two or two divided pinions or transmission gears is shifted in phase from each other by an angle backlash. It is in the place where it is provided.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG.

The embodiment shown in FIGS. 1 and 2 is different from the known example shown in FIGS. 3 and 4 except for the combined structure of the external gear, the internal gear and the eccentric body, and the structure of the transmission gear. Since they are the same, only the combined structure of the external gear, the internal gear, and the eccentric body and the structure of the transmission gear will be described here, and the description of the other structures will be omitted.

The combination structure of the eccentric bodies 6 ₁ and 6 ₂ , the external gears 8 ₁ and 8 ₂ and the internal gear 10 is as follows. _Two external gears 8 ₁ and 8 ₂ through which the three eccentric body shafts 4 pass are provided in the axial direction, and eccentric body bearing holes 19 ₁ and 1 formed in the external gears 8 ₁ and 8 ₂ are provided.
One external gear 8 ₁ is provided with 9 ₂ offset by an angle θ in the normal rotation direction, and the eccentric body bearing hole 19 ₂ formed in the other external gear 8 ₂ is offset by an angle θ in the reverse rotation direction. Is provided. The angle θ corresponds to half the size of the angle backlash described above. As a result, the eccentric body 6 ₁ , the external gear 8 ₁ , the eccentric body bearing hole 19 ₁ and the internal gear 10 constitute one set of positive gears, and the eccentric body 6 ₂ , the external gear 8 ₂ and the eccentric body another set of reverse gear set is constituted by a bearing hole 19 ₂ and the internal gear 10.

The transmission gears 3 ₁ and 3 ₂ are divided into _two in the axial direction or a set of two gears, and can be stopped by a retaining bolt 20 by shifting the phases in the circumferential direction. The transmission gears 3 ₁ , 3 ₂ are fixed to the eccentric body shaft 4 by a key 21. The transmission gears 3 ₁ carry out the torque transmission in the forward rotation direction, and the transmission gears 3 ₂ carry out the roles of the transmission gears 3 ₁ and 3 ₂ so as to transmit the torque in the reverse rotation direction.

In the above, the forward rotation and the reverse rotation may be opposite to each other.

These are attached as follows.

First, one set for one rotation direction, that is, an eccentric body
In the combination of 6 ₁ , the external gear 8 ₁ and the internal gear 10, the state in which the angle backlash is eliminated, that is, the angle backlash is set to zero.

In this state, the other 1
The set, that is, the combination of the eccentric body 6 ₂ , the external gear 8 ₂ , and the internal gear 10 has an angle 2θ such that the angle backlash is zero.
Just slide it and attach it. As a result, the eccentric bodies 6 ₁ , 6 ₂ ,
The angular backlash in the external gears 8 ₁ and 8 ₂ and the internal gear 10 is eliminated.

Next, the transmission gear 3 ₁ is attached in alignment with one rotation direction, and in this state, the transmission gear 3 ₂ is displaced in the other rotation direction by the angle backlash, and is fixed with the bolt 20. In this mounting method, in advance angle backlash measured beforehand, the transmission gear 3 ₁ by shifting from each other by an angle that amount,
3 ₂ may be attached stop, mounted in accordance with the forward or reverse direction the transmission gear 3 ₂ as described above, then the transmission gear
3 ₁ may be attached with a fixing bolt 20 at an angle so as to eliminate the angle backlash.

Although the above embodiment has been described as a speed reducer, the present invention can be used as a speed increaser, and when the rotation is transmitted from the input shaft to the planetary gear mechanism, all the second speed change gears are provided. It can be applied to the speed reducer.

The present invention also includes a configuration in which the transmission gear is divided into two or two in the axial direction and the pinion is divided into two or two in the axial direction.

Further, the present invention includes a planetary gear mechanism of a shaft rotation type and a planetary gear mechanism of different types having different structures of external gears with the outer case fixed.

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

In addition to the angular backlash between the external gear and the internal gear of the power transmission mechanism, the angular backlash between the pinion and the transmission gear, which is the second reduction means, can be eliminated, so that the entire mechanism can be eliminated. The angle backlash can be reliably achieved.

Since there is no play or play even when moving from normal rotation to reverse rotation, accuracy is improved when used as a transmission mechanism of a control device.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
3 is a sectional view showing a known planetary gear mechanism, and FIG. 4 is a sectional view taken along the line AA in FIG. Explanation of symbols 1: Input shaft 2: Pinion 3 ₁ , 3 ₂ : Transmission gear 4: Eccentric body shaft 6 ₁ , 6 ₂ : Eccentric body 7: External teeth 8 ₁ , 8 ₂ : External gear 9: Eccentric bearing 10 : Internal gear 19 ₁ , 19 ₂ : Eccentric body bearing hole 20: Set bolt

Claims (1)

[Claims] 1. A pinion provided on an input shaft, a plurality of transmission gears meshing with the pinion, an eccentric body shaft rotated by the transmission gears, and an eccentric body bearing on an eccentric body provided on the eccentric body shaft. In the planetary gear mechanism that performs acceleration / deceleration consisting of an external gear that is held via an internal gear that meshes with the external gear, an external gear and an internal gear that are held by the eccentric body shaft A plurality of combinations are provided in the axial direction of the eccentric body, and in at least two combinations of the external gear and the internal gear among the combinations of the plurality of sets, the eccentric body bearing hole formed in one of the external gears is formed in the normal direction. The eccentric body bearing hole formed on the other external gear is shifted by half the angular backlash in the rolling direction, and the eccentric body bearing hole formed in the other external gear is shifted by half the angular backlash. one The planetary gear mechanism is characterized in that one is divided into two or two in the axial direction, and one of the two or two divided pinions or transmission gears is provided to be phase-shifted from each other by an angle backlash. Angle backlash removal device in.