JPH09303498A - Screw hole mechanism for fastening of flexible mesh type gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screwing mechanism capable of accurately fastening and fixing to another member in a flexible mesh type gear device. A flange 2a of a housing 2 (rigid internal gear) of a flexible meshing gear device 1 is fastened and fixed to a motor flange 7b by a fastening bolt 8. The screw hole 20 of the flange 2a is formed with a large counterbore 21 including the opening of the corresponding screw hole 70 on the motor flange side. When the flange 2a is fastened and fixed to the motor flange 7b, even if a protrusion 71 is formed on the opening edge of the corresponding screw hole 70, the flange 2a is not adversely affected. Does not decrease and the rotation angle transmission error, vibration, etc. do not increase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw hole mechanism used in a flexible mesh type gear device to fasten and fix a component of the device to another member using a fastening screw.

[0002]

2. Description of the Related Art A flexible mesh type gear device generally has an annular rigid internal gear, a cup-shaped flexible external gear, and an elliptical wave generator. The flexible external gear is bent in an elliptical shape and partially meshes with the rigid internal gear. Then, when the wave generator is rotated at a high speed by a motor or the like, the meshing position of both gears moves in the circumferential direction, and relative rotation corresponding to the tooth number difference of both gears occurs between both gears. Therefore, if one gear is fixed, the decelerated rotation output can be taken out from the other gear.

[0003]

One of the factors that adversely affects the rotation accuracy of a flex meshing type gear device is that the flatness of the mounting surface of the mating member to which the device is mounted and fixed is insufficient. Can be mentioned. In particular, the rise around the screw hole opening that occurs when the bolt is tightened may cause deformation of the rigid internal gear or other component on the side of the flexible meshing gear device that is tightened and fixed to the mounting surface. is there. When such deformation occurs, a gear pitch error is caused, a rotation angle transmission error becomes large, and vibration and the like also increase.

An object of the present invention is to propose a fastening screw hole mechanism for a flexible meshing type gear device which can avoid such an adverse effect.

[0005]

In order to solve the above-mentioned problems, the present invention provides an annular rigid internal gear, an annular flexible external gear, and a flexible external gear in the radial direction. In a flexible meshing type gear device having a wave generator that flexibly bends to partially mesh with the rigid internal gear and moves the meshing position in the circumferential direction, each of the parts constituting the device. Has at least one screw hole formed for fastening and fixing the screw to another member, and the opening portion of the screw hole includes an opening of a corresponding screw hole formed on the side of the other member that abuts the screw hole. The feature is that it is set to the size.

[0006] For example, a counterbore is provided at an opening of a screw hole opened for fastening and fixing a rigid internal gear to another member.
Process countersunk spots etc.

According to the present invention, even if the opening portion of the corresponding screw hole of the counterpart member with which the screw hole abuts rises by tightening the screw, the screw hole opening portion includes the opening of the corresponding screw hole. Because of its size, it has a space to allow the raised parts to escape. Therefore, it is possible to avoid the adverse effect that the raised portion is pressed against the component on the side of the flexible meshing gear device to deform the component. Therefore, by adopting the mechanism of the present invention, even if the flatness of the screw hole portion of the member on the side where the flexible meshing gear device is fastened and fixed is not appropriate, the mounting can be performed accurately and the rotation angle transmission The error will not increase.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows an example of a flexible mesh type gear device to which the present invention is applied. The flexible mesh type gear device 1 is suitable when directly connected to the motor 7. The device 1 includes a device housing 2, and a flange 2a for mounting on the motor side is formed at one open end of the device housing 2. An outer ring 3a of a cross roller bearing 3 is fixed to the other open end side of the device housing 2. The inner ring 3b of the cross roller bearing 3 is integrated with the output member.

A rigid internal gear is integrated with the apparatus housing 2. That is, the inner teeth 4 are formed on the inner peripheral surface of the housing 2. Inside the device housing 2, a cup-shaped flexible external gear 5 is arranged. This flexible external gear 5 has external teeth 5a on the outer peripheral surface at one open end.
A body portion 5b formed with a ring, an annular diaphragm 5c continuous to the other open end of the body portion 5b, and a thick annular boss 5 continuous to the central portion of the diaphragm 5c.
and d. The annular boss 5d is fixed to the output member integrated inner ring 3b.

A wave generator 6 is fitted inside the flexible external gear 5 of this construction. The wave generator 6 includes, for example, an elliptical rigid cam plate 6a and a ball bearing 6b fitted on the outer periphery of the rigid cam plate 6a. An output shaft 7a of the motor 7 is connected and fixed to the center of the rigid cam plate 6a via a plug 6c. Flange 7b for mounting the motor 7
Are fixed to the flange 2a of the device housing 2.

Here, a screw hole 20 for fastening is formed in the flange 2a of the apparatus housing 2 in which the rigid internal gear is integrally formed. A corresponding screw hole 70 with which this screw hole 20 abuts is formed on the flange 7b side of the motor 7. Fastening bolts 8 are mounted in these screw holes 20 and 70 to fasten and fix them. A plurality of these screw holes 20 and 70 are formed in the circumferential direction at regular angular intervals.

FIG. 1B is an enlarged view of the screw holes 20 and 70. As shown in this figure, the screw hole 20 on the side of the device housing 2 has a deep counterbore 21 formed at the open end portion thereof. For example, the deep counterbore 21 having an inner diameter of about 1.2 to 2 times the diameter of the screw hole and a depth of 0.05 mm or more is formed.

In the flexural mesh type gear device 1 constructed as described above, the device housing 2 is fastened and fixed to the motor 7 side by fastening bolts 8. By tightening with the bolt 8, the corresponding screw hole 70 on the side of the motor flange 7b
A bulge 71 may be formed at the opening edge of the. Even if such a bulge 71 is formed, a counterbore 21 having a size including the bulge 71 is formed in the facing screw hole 20. Therefore, since the raised portion 71 has this counterbore 21, it does not press against the apparatus flange 2a and cause deformation of the flange 2a. Therefore, the device flange 2a and the motor flange 7b can be accurately attached to each other. Therefore, there is no possibility that the rotation angle error of the flexural meshing gear device 1 becomes large.

The screwing mechanism of the present invention is not limited to the screw hole on the apparatus housing (rigid internal gear) side as described above. The same applies to other screw holes. For example, it can be applied to a screw hole of a fastening portion between the device housing 2 and the side of the cross roller bearing 3.

The counterbore or the like formed at the opening of the screw hole may have a shape other than that shown in the drawing. For example, it may be a counterbore. In any case, it suffices if a space capable of escaping the swell formed in the opening on the side of the corresponding screw hole can be released.

[0016]

As described above, in the flexible mesh type gear device of the present invention, the opening portion of the screw hole formed for fastening and fixing to another member such as a motor is provided with a corresponding screw on the side of the other member. The size is set to include the opening of the hole. Therefore, even if a bulge is formed on the opening edge of the corresponding screw hole at the time of fastening and fixing, no adverse effect such as deformation occurs on the side of the flexible meshing gear device. It can be fastened and fixed to the other member side without increasing the vibration and rotation angle transmission error.

[Brief description of drawings]

FIG. 1 (A) is a schematic configuration diagram showing a flexible meshing gear device to which the present invention is applied, and FIG. 1 (B) shows a screw hole formed on the device housing side and a corresponding screw hole formed on the motor flange side. It is an enlarged view which extracts and shows a part.

[Explanation of symbols]

 1 Flexible mesh type gear device 2 Device housing (rigid internal gear) 2a Flange 20 Screw hole 21 Counterbore 5 Cup-shaped flexible external gear 6 Wave generator 7 Motor 7b Motor flange 70 Corresponding screw hole 71 Raised

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[Procedure amendment]

[Submission date] August 2, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

Claims (1)

[Claims] 1. A ring-shaped rigid internal gear, an annular flexible external gear, and the flexible external gear are bent in the radial direction and partially meshed with the rigid internal gear. In a flexible meshing type gear device having a wave generator that moves a meshing position in the circumferential direction, at least one screw hole formed for attaching and fixing each of the above-mentioned parts constituting the device to another member. And the opening portion of the screw hole is set to a size including the opening of the corresponding screw hole formed on the side of the other member that abuts the screw hole. mechanism.