JPH0783292A - Angle transmission error correcting method of wave motion gear device - Google Patents

Abstract

PURPOSE:To provide a means to correct the angle transmission error of a wave motion gear device simply without replacing the component parts. CONSTITUTION:At the outer periphery of the rigid inner teeth gear 31 of a wave motion gear device 3, a circular member 35 is provided. To the circular member 35, eight screw holes 35a to 35h are formed at the same angular intervals, and plunger screws 35A to 35H are screwed in to the screw holes. The angle transmission error of the wave motion gear device 3 is measured, and after that, the fastening amount of each plunger screw is adjusted to eliminate the error. By the operation to regulate the fastening amounts of the plunger screws so as to deform the rigid inner teeth gear 31 in such a way, angel transmitting errors can simply be corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of adjusting an angle transmission error in a wave gear device. The present invention also relates to a wave gear device having an angle transmission error adjusting function.

[0002]

2. Description of the Related Art A so-called cup-type wave gear device is known as a typical wave gear device. This device is composed of an annular rigid internal gear, a cup-shaped flexible external gear arranged inside this, and a wave generator arranged inside this. The internal gear and the external gear can mesh with each other, and generally the number of teeth of the external gear is set to be two less, and the external gear is bent into an elliptical shape by the wave generator. And is set to mesh with the internal gear at two points facing each other in the diametrical direction. When the wave generator is connected to a rotation source such as a motor and rotated at high speed, the meshing positions of these move in the circumferential direction, causing relative rotation between the internal gear and the external gear depending on the number of teeth. To do. Since this type of device can greatly reduce the input rotation with a small number of parts, it is used as a compact reducer incorporated in machine tools, robots and the like.

[0003]

When constructing a highly accurate positioning mechanism or the like using this wave gear device, it is necessary to suppress the angle transmission error of the wave gear device itself as much as possible. For this purpose, it is necessary to improve the processing accuracy and the assembly accuracy of each component constituting the device. In the past, the rigid external gear, the flexible internal gear, etc. were replaced so that the angle transmission error was adjusted to fall within the required range. However, the method of suppressing the angle transmission error by exchanging the components in this way is complicated in work, and the angle transmission error cannot be easily improved to a required degree.

An object of the present invention is to pay attention to the fact that the cause of the angle transmission error is mainly due to the rigid internal gear.
It is to propose a method capable of suppressing an angle transmission error of a wave gear device by a simple operation. Another object of the present invention is to propose a wave gear device having an angle transmission error adjusting function by this method.

[0005]

In the method of the present invention, an annular rigid internal gear, an annular flexible external gear arranged inside the annular internal gear, and a radial flexure of the external gear are provided. And a wave generator that causes the external gear to relatively rotate with respect to the internal gear by moving these meshing positions in the circumferential direction while engaging with the internal gear at a plurality of points. In the wave gear device, first, by rotating the wave generator, the angle transmission error of the wave gear device is measured, and then, based on this measurement result, the internal gear is adjusted to eliminate the angle transmission error. An external force is applied to the internal gear to slightly deform it in the radial direction.

Further, in the wave gear device of the present invention,
A plurality of pressing members capable of pressing the outer peripheral surface of the internal gear at predetermined angular intervals are arranged on the outer periphery of the internal gear, and the pressing force of these pressing members is set to be adjustable. Therefore, by adjusting the pressing force of these pressing members, the rigid internal gear can be slightly deformed so as to suppress the angle transmission error of the wave gear device.

It should be noted that, instead of the pressing member, a plurality of tension members capable of pulling the internal gear to the outside in the radial direction are arranged, and the pulling force by these tension members is adjusted to transmit the angle of the wave gear device. The internal gear may be slightly deformed so as to suppress an error.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an actuator to which the present invention is applied. The actuator 1 of this example is basically composed of a motor 2, a cup-type wave gear device 3, and an encoder 4 for obtaining rotation information.

The cup type wave gear device 3 itself has a general structure, and has an annular rigid internal gear 31.
And the cup-shaped flexible external gear 3 arranged inside
2 and an elliptical wave generator 33 arranged inside this. The portion of the cup-shaped flexible external gear 32 where the external teeth 32a are formed is bent into an elliptical shape by the wave generator 33 and meshes with the internal teeth 31a of the rigid internal gear at two diametrical positions. . The number of external teeth 32a is 3 for internal teeth.
The number of teeth is set to 2n (n is a positive integer) less than the number of teeth of 1a. Therefore, when the wave generator 33 that rotates at a high speed is rotated by the motor 2, the meshing position of these two gears moves in the circumferential direction, and relative rotation is generated between the gears according to the difference in the number of teeth. In this example, the rigid internal gear 31 is fixed to the support member 1a side, and therefore, the decelerated rotation is output from the output shaft 34 that is coaxially fixed to the cup bottom surface of the cup-shaped flexible external gear 32. , Is transmitted to the side of the load (not shown).

Here, in this example, the rigid internal gear 3 is used.
A rigid annular member 35 is concentrically arranged on the outer circumference of the No. 1. The inner diameter of the annular member 35 is slightly larger than the outer diameter of the rigid internal gear 31. The annular member 35 has a fixed angular interval of 8 degrees in this example.
Individual screw holes 35a to 35h are formed, and each of the screw holes has a plunger screw 35A to 35h.
H is screwed. These plunger screws 35
By screwing A to 35H, the outer peripheral surface 33a of the rigid internal gear 33 can be pressed by their tips, and the pressing force can be adjusted by adjusting the screwing amount.

In this example, the angle transmission error of the wave gear device 3 is adjusted as follows. First, the wave gear device 3
By rotating the wave generator 33, the characteristic of the angular transmission error per rotation of the wave generator 33 is measured as shown in FIG. In this measurement, the measurement start point is set in advance. Then, the amplitude of the waveform of the angular transmission error is reduced by screwing the plunger screw corresponding to the position where the peak portion of the waveform of the obtained angular transmission error appears. This adjustment is performed by repeatedly rotating the wave generator 33, and the amplitude of the obtained waveform of the angular transmission error is adjusted to fall within the target range.

According to the measurement by the present inventor, the angle transmission error of the wave gear device 3 can be suppressed within a predetermined range by slightly deforming the rigid internal gear in the radial direction in this way. Was confirmed.

As described above, in the wave gear device of this embodiment, the angle transmission error can be suppressed within the target range by adjusting the screwing amount of each plunger screw attached thereto. Therefore, unlike the conventional adjustment method, it is not necessary to replace components such as the rigid internal gear and the flexible external gear to adjust the angle transmission error.

The mechanism for deforming the rigid internal gear in order to eliminate the angle transmission error is not limited to the above structure, and other mechanisms can be adopted.
FIG. 3 shows an example thereof. In the example shown in the figure, a ring-shaped groove 6 that is opened to the side is formed between the outer peripheral surface 31b of the rigid internal gear 31 of the wave gear device 3 and the housing 5 to which it is fixed. It has a configuration in which a deformable sphere 7 and a fastening screw 8 for deforming it are attached. When the fastening screw 8 is tightened, the spherical body 7 is deformed in the direction in which the outer peripheral surface 31a of the rigid internal gear 31 is pressed. Therefore, by adjusting the tightening amount of the fastening screw, the rigid internal gear 31 can be deformed as necessary. The sphere 7 and the fastening screw 8 may be arranged at predetermined angles over the circumferential direction of the annular groove 6.

FIG. 4 shows still another mechanism for deforming the rigid internal gear. In this example mechanism,
By tensilely deforming the annular rigid internal gear of the wave gear device shown in FIG. 1 from the outside toward the outside in the radial direction,
The angle transmission error is adjusted. In FIG. 4 and the following description, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

The annular member 35 arranged outside the rigid internal gear 31 in the wave gear device 3 of this embodiment is set so that its inner diameter is slightly larger than the outer diameter of the internal gear. In the annular member 35, screw through holes are formed at regular angular intervals in the circumferential direction. In this example, six screw through holes 41A to 41F are formed at intervals of 60 degrees. Screw holes 42A through 42A are formed in the outer peripheral surface of the rigid internal gear 31 corresponding to these screw through holes.
F is formed. Then, through each screw through hole,
The screws 43A to 43F are inserted. These screws are composed of a wide head 43a and leg portions 43b, and the leg portions are formed with male screw portions 43c which can be screwed into the above-mentioned screw holes 42A to 42F. It is screwed and fixed in the hole.

In this example, each of the screws 43A to 43A
By tightening F, the portion of the rigid internal gear 31 into which these screws are screwed is pulled outward in the radial direction. Therefore, by adjusting the tightening amount of each of the screws 43A to 43F, the rigid internal gear 31 can be slightly deformed, and the angle transmission error of the wave gear device can be reduced.

[0019]

As described above, according to the present invention, the rigid internal gear, which is a component of the wave gear device, is slightly deformed in the radial direction to suppress or eliminate the angular transmission error of the wave gear device. I am trying to do it. Therefore, as compared with the conventional method of adjusting the angle transmission error by exchanging each component of the wave gear device, the angle transmission error can be adjusted by a simple operation and in a short time. .

[Brief description of drawings]

FIG. 1 is a diagram showing an actuator to which the method of the present invention is applied, FIG. 1A is a configuration diagram showing its configuration in a half cross-sectional state, and FIG.

FIG. 2 is a waveform diagram showing an example of an angle transmission error waveform in the wave gear device having the configuration of FIG.

FIG. 3 is a partial configuration diagram showing another example for giving deformation to a rigid internal gear.

FIG. 4 is an explanatory view showing still another example for giving deformation to a rigid internal gear.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Actuator 2 ... Motor 3 ... Wave gear device 31 ... Rigid internal gear 31a ... Internal teeth 31b ... Rigid internal gear outer peripheral surface 32 ... Cup type possible Flexible external tooth gear 32a ... External tooth 35 ... Annular member 35a-35h ... Screw hole 35A-35H ... Plunger screw

Claims (3)

[Claims] 1. An annular rigid internal gear, an annular flexible external gear arranged inside the annular internal gear, and a plurality of points with respect to the internal gear by bending the external gear radially. In a wave gear device having a wave generator that relatively rotates the external gear with respect to the internal gear by moving these meshing positions in the circumferential direction while rotating the wave generator. Then, the angle transmission error of the wave gear device is measured, and based on this measurement result, an external force is applied to the internal gear so as to eliminate the angular transmission error, and the internal gear is radially moved. A method for adjusting an angle transmission error of a wave gear device, characterized by slightly deforming. 2. An annular rigid internal gear, an annular flexible external gear arranged inside the annular internal gear, and a plurality of points with respect to the internal gear by bending the external gear radially. In the wave gear device having a wave generator that causes the external gear to relatively rotate with respect to the internal gear by moving these meshing positions in the circumferential direction, the outer periphery of the internal gear is , A plurality of pressing members capable of pressing the outer peripheral surface of the internal gear at predetermined angular intervals are arranged, and these pressing members are capable of adjusting the pressing force against the internal gear, By adjusting the pressing force of the pressing member of
A wave gear device with an angle transmission error adjusting function, characterized in that the angle transmission error of the wave gear device is adjusted. 3. The angular transmission error according to claim 2, wherein instead of the pressing member, a plurality of tension members that can pull the internal gear toward the outer side in the radial direction are arranged. Wave gear device with adjusting function.