JPH0321774B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention meshes a planetary gear (external gear) having a circular arc tooth profile or a trochoidal tooth profile with an internal gear having a circular tooth profile consisting of a pin or a pin and a roller. This relates to a planetary gear system.

(Prior art) In a gear transmission mechanism, there is play or looseness between the gears that mesh with each other or in the means for attaching the gears to the shaft, and when moving from normal rotation to reverse rotation, rotation on the driving side immediately becomes rotation on the driven side. do not have. (Response is delayed) In planetary gear mechanisms, multiple meshes occur in parallel to increase transmission torque, maintain strength, and maintain balance. The play and play in the meshing parts will be reduced due to interference, but since power is originally supposed to be transmitted at each meshing part, play and play will still occur when rotating from normal to reverse rotation.

The above-mentioned play and backlash become relative when there are a plurality of meshing parts, and this relative play and backlash is hereinafter referred to as angular backlash.

Hereinafter, a conventionally known planetary gear device will be explained with reference to FIGS. 1 and 2.

Figures 1 and 2 show a reduction gear as an example of a planetary gear mechanism, in which two eccentric bodies 2 and 3 are integrally fixed to an input shaft 1 with a phase shift of 180°. The respective eccentric bodies 2 and 3 swing and rotate the external gears 4 and 5 by their rotation. This rocking rotation is allowed by the inner pin 6 rotating along the inner periphery of the inner roller holes (inner pin holes when no rollers are provided) 7 and 8.

Trochoidal tooth profiles 9 and 10 are formed on the outer peripheries of the external gears 4 and 5, and the trochoidal tooth profiles 9 and 10 mesh with an external pin 12 of a frame-cum-internal gear 11.

The inner pin 6 is connected to the output shaft 13,
With one rotation of the input shaft 1, the output shaft 13 is decelerated to 1/the number of teeth of the internal gear (outer pin 12). (However, when the difference in the number of teeth between the external pin 12 and the external gears 4 and 5 is one tooth.) (Problem to be solved by the invention) In the conventional device described above, the eccentric bodies 2 and 3 are integrally constructed; is fixed to the input shaft 1 by a single key 14, the relationship between the eccentrics 2 and 3 and the planetary gear and internal gear is uniquely determined, and these relationships can be moved separately (relatively). It was not possible to adjust the position.

Therefore, if there is an angular bump in the meshing between the planetary gears (external gears) 4 and 5 and the internal gear 11, which are moved by the eccentric body 2, the planetary gears (external gears) 4, 5) and the internal gear 11 is switched to the reverse direction, a deviation equivalent to the angle backlash occurs, which causes a delay in rotational response.

That is, in the conventional device, a shift (play) between the driving side and the driven side occurs due to angular backlash when changing from normal rotation to reverse rotation or vice versa.

The presence of such angular bumps causes a decrease in accuracy when the transmission mechanism is used as a control device, and also causes a decrease in durability of the transmission device due to impact.

In order to eliminate and reduce the angle breakage mentioned above, it has been necessary to increase the machining accuracy of the parts and waste time selecting and combining parts, but even with this, it is difficult to remove the angle breakage sufficiently, and as a result, was becoming expensive.

The present invention focuses on the fact that this type of planetary gear mechanism has a plurality of external gears, and attempts to eliminate or reduce angular bumps with a simple device that adjusts the position of the inner pin hole. It is.

(Means for Solving the Problems) The present invention is characterized in that at least one of the plurality of planetary gears has a position where it meshes with the internal gear when rotating in one direction (normal rotation direction). An inner pin hole (inner roller hole) is drilled in at least one other planetary gear, and an inner pin hole (inner roller hole) is formed in at least one other planetary gear at a position where it meshes with the internal gear when rotating in the other direction (reverse direction). The holes for the inner pins (inner rollers) of the plurality of planetary gears are located at positions shifted from the theoretical meshing position by an amount equivalent to the angle backlash.

(Example) In the present invention, attention was paid to the following points.

If the transmission mechanism has two or more meshing parts, one of them may be used to make the angular buckle in the forward direction zero, and the other one to make the angular buckle in the reverse direction to be zero.

Originally, the reason for providing multiple meshes was to transmit large torque, improve durability, and eliminate load balance in the circumferential direction.

An embodiment of the present invention will be explained below with reference to FIGS. 3 and 4, mainly regarding the differences from the conventional apparatus shown in FIGS. 1 and 2.

The eccentric bodies 2 and 3 are integrally formed with a phase shift of 180°, and are fixed to the input shaft 1 by a key 14. Therefore, theoretically, all the outer pins (internal gears) 11 and inner pins (inner rollers) 6 and 2
The two planetary gears (external gears) 4 and 5 are supposed to mesh with each other at the same time, but the clearance between the teeth 9 and 10 of the planetary gears 4 and 5 and the external pin (internal gear) 12, and the frame Machining error of internal gear 11 or eccentric holes 15, 16 of planetary gear and eccentric bearings 17, 1
There are clearances between 8 and 8 for the purpose of eliminating unnecessary engagement or errors in machining, etc., and when actually engaging (moving), the sum of these clearances will result in the actual In this case, only the internal gears effective for load transmission mesh with each planetary gear at the target position.

That is, in the example shown in FIG. 2, the planetary gear 4 has teeth m2 to m6 of the internal gear 11 and internal pins p2 to p5.
Also, the planetary gear 5 has teeth m11 to m of the internal gear 11.
15 and inner pins p7 to p10, respectively.

Therefore, when rotated in the counter-arrow direction (clockwise) from the state shown in FIG. Teeth m14 to m18 and inner pin p
7 to p1 will mesh with each other, but since there is some clearance between them, they will only mesh after rotating until this clearance disappears, resulting in a rotation delay (driving drive) corresponding to the clearance. It is inevitable that there will be a rotation delay on the driven side relative to the rotation on the driven side.

In the present invention, in the state shown in FIG. 2, with the planetary gear 4 and internal gear 11 and the internal pin 6 fixed (maintained in the state shown), the planetary gear 5 is rotated about the center B5 as shown by the opposite arrow. (clockwise),
As shown in Fig. 3, stop at the position where the planetary gear 5 touches (meshing) the internal gear 11 (at this time, the position of the internal pin hole 8 is ignored and rotates), and it is fixed (held) at this position. Then, an inner pin hole is bored at a position where it will theoretically mesh with the inner pin 6 (as shown in FIG. 3), and then assembled.

That is, in the state shown in FIG. 3, the planetary gear 4, the internal gears m2 to m6, and the internal pins p2 to p5,
The internal gears m5 to m9 and the internal pins p2 to p5 mesh with each other, and there is no clearance in both forward and reverse directions.

In addition, in the above embodiment, an example was explained in which two planetary gears were used, but it goes without saying that it is very good to have three or more planetary gears, and in this case, the position of the inner pin hole of the third and subsequent planetary gears is You can leave it in the theoretical position.

As described above, the present invention allows a plurality of planetary gears to be rotated by shifting the positions of the inner pin holes, and when the number of planetary gears is n, at least one gear is rotated in the normal rotation direction, and at least one other gear is rotated in the normal rotation direction. The characteristic point is that the inner pin holes are simultaneously engaged in the reverse direction, and it is desirable to determine the amount of positional deviation of the inner pin hole in the actually assembled state, but in actual production, it is recommended to use empirical values. Once the holes are drilled at the predetermined positions, the other operations are carried out in exactly the same manner as before.

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

When this planetary gear mechanism is used as a control mechanism, there is no backlash in both forward and reverse directions, so there is no response delay and control accuracy is improved.

Since the angle backlash can be changed to the preload position, it can now be used for applications that require preload.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a conventional planetary gear mechanism, Fig. 2 is a sectional view taken along line AA in Fig. FIG. 2 is a side view of the planetary gear system of the invention. 2, 3... Eccentric body, 4, 5... Planetary gear, 6...
...Inner pin (inner roller), 7, 8...Inner pin hole (inner roller hole), 11...Frame and internal gear, 12...Outer pin.

Claims (1)

[Scope of Claims] 1. The internal gear consists of a pin, etc., and the planetary gear (external gear) consists of a trochoidal tooth profile, etc., and both gears are meshed, and the planetary gear is attached to the shaft with approximately equal phase difference. In a planetary gear mechanism that increases and decelerates by oscillating rotation using an eccentric body, an inner pin (inner roller), and an inner pin hole (inner roller), at least one of the plurality of planetary gears has one An inner pin hole (inner roller hole) is drilled at a position where it meshes with the internal gear when rotating in the other direction (forward rotation direction), and an inner pin hole (inner roller hole) is drilled at a position that meshes with the internal gear when rotating in the other direction (reverse rotation direction). An inner pin hole (inner roller hole) is drilled at the position where the gear meshes with the gear, and the drilled position of the inner pin (inner roller) hole of multiple planetary gears is shifted from the theoretical meshing position by an amount equivalent to the angle backlash. A planetary gear device characterized by: