JPH10291185A - Harmonic speed reducer and industrial robot with harmonic speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect a wave generator to a motor shaft with the wave generator assembled into a harmonic speed reducer. SOLUTION: In a harmonic speed reducer 10 comprising a circular spline 13, a flex spline 12 which is inserted into and engaged with the circular spline 13, a wave generator 11 inserted into the flex spline 12, a first outer cabinet 17a fixed to the flex spline 12, and a second outer cabinet 17b fixed to the circular spline 13, the wave generator 11 is supported by the first outer cabinet 17a through a bearing 16. Thus an input shaft 7 can be inserted fixedly into the wave generator 11 with the wave generator 11 assembled into the harmonic speed reducer 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a harmonic reducer and an industrial robot having the harmonic reducer.

[0002]

2. Description of the Related Art Conventionally, the structure of an industrial robot equipped with a harmonic reducer is shown in FIG. FIG. 2 is a sectional side view of a harmonic reducer mounted on a turning base of an industrial robot according to the prior art. In the figure,
Reference numeral 1 denotes a turning base, and a motor base 2 is fixed to the bottom of the turning base 1. A motor 4 is fixed to the motor base 2 via a flange 3. The motor 4 has a built-in bearing 5 for rotatably supporting the motor shaft 6. An input shaft 7 is attached to the motor shaft 6, and the input shaft 7 extends downward through the center opening of the flange 3 in the figure. Reference numeral 10 denotes a harmonic reducer. The harmonic reducer 10 includes a wave generator 11
, Flex spline 12 and circular spline 1
3, a cross roller bearing 14, and a flange 15. The wave generator 11 is obtained by attaching a flexible bearing 11b to the outer periphery of an elliptical cam plate 11a, and is fixed to the motor shaft 6 by bolts 8 together with the input shaft 7 inserted into the center shaft 11c. .
Since the wave generator 11 is not supported by the harmonic reducer 10, the wave generator 11 is fixed to the motor shaft 6 and hung inside the harmonic reducer 10 as described above. The flexspline 12 is a thin-walled cylindrical metal elastic body having a tooth groove formed on the outer periphery, and its bottom is fixed to the flange 15 and the wave generator 11 is fitted therein, so that the flexspline 12 is bent in an elliptical shape. . The circular spline 13 is a pressed annular rigid body having a true circular inner circumference with a tooth groove formed therein, and a tooth groove is formed on the inner circumference thereof and meshes with a tooth groove on the outer circumference of the flexspline 12. . The inner ring 14 a of the cross roller bearing 14 is fixed to the motor base 2 via the circular spline 13. A flange 15 is fixed to the outer ring 14b of the cross roller bearing 14, and the flange 15 is fixed to a fixed base of an industrial robot (not shown). Outer ring 14b of cross roller bearing 14 and flange 15
Constitutes a first outer casing 17a that forms the lower outer shape of the harmonic reducer 10. The inner race 14a of the cross roller bearing 14 and the circular spline 1
Reference numeral 3 denotes a second outer housing 17b which forms the outer shape of the upper part of the harmonic reducer 10. Flexspline 1
Since 2 is bent in an elliptical shape, its tooth groove is engaged with the tooth groove of the circular spline 13 at a position corresponding to the major axis of the ellipse, and is separated at a position corresponding to the minor axis. Therefore, when the wave generator 11 is rotated, the circular spline 13 and the flex spline 12
Are sequentially engaged, and the circular spline 13 and the flex spline 12 relatively rotate according to the difference in the number of teeth between the two.

[0003]

However, the prior art has the following problems. (1) Since the wave generator 11 is fixed to the motor shaft 6 and then inserted into the flex spline 12,
It is difficult to assemble with high accuracy by adjusting the misalignment and the inclination of the shaft. (2) Since the wave generator 11 is fixed to the motor shaft 6 and then inserted into the flex spline 12,
In addition to the motor base 2, the flange 3 is required, and since these parts require precision, manufacturing is difficult and expensive. (3) Wave generator 11 is flex spline 1
2, the input shaft 7 can be inserted only from the upper part of the harmonic reducer 10, so that the degree of freedom in designing a mechanism using the harmonic reducer 10 is small.

[0004]

In order to solve the above problems, the present invention provides a method in which a wave generator is supported by an outer casing of a harmonic reducer, and the wave generator is input to the wave generator while the wave generator is mounted on the harmonic reducer. Insert the shaft so that it can be joined.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Since the basic configuration is the same as the conventional technology,
The different parts will be described. FIG. 1 is a side sectional view of a harmonic reducer attached to a turning base of an industrial robot showing an embodiment of the present invention. The central axis 11a of the wave generator 11 has a hollow cylindrical shape, and has an inner surface with a spline. The end of the central shaft 11a is rotatably supported by the flange 15 via a bearing 16, and is exposed to the outside through an opening provided at the center of the flange 15. The motor 4 is directly fixed to the motor base 2.
The input shaft 7 is fixed to the motor shaft 6 with bolts 8, and a spline is cut on the outer periphery thereof, and is inserted into the center shaft 11 a of the wave generator 11. Since the harmonic reducer 10 has such a configuration, in order to connect the harmonic reducer 10 and the motor 4, the input shaft 7 is inserted into the center axis 11 a of the wave generator 11 from outside the harmonic reducer, and the spline is removed. There is no need to take the wave generator 11 out of the harmonic reduction gear 10 and fix it to the motor shaft 6, and then reinsert it into the harmonic reduction gear 10. Therefore, it is easier to assemble and remove the motor 4 from the turning base 1 as compared with the related art. Also, the input shaft 7 is the harmonic reducer 1
0, the central axis 11 of the wave generator 11
a can also be inserted. Further, since the motor base 2 only needs to have a hole having a diameter enough to allow the input shaft 7 to pass therethrough, no separate component such as a flange is required between the motor base 2 and the motor 4. The input shaft 7 and the wave generator 1
1 is not limited to the fitting of the spline, for example, a wave generator 11
Can be connected to the input shaft 7 without being separated from the harmonic reducer 10. In the present embodiment, the wave generator 11 is
Although it was configured to be supported by the flange 15 fixed to 2,
It may be configured to be rotatably supported by a flange fixed to the circular spline 13. The wave generator 11 is an outer casing 17a, 17b of the harmonic reducer 10.
The structure of the components is not limited as long as the structure is rotatably supported on the device. For example, the flange 15 is a flex spline 1
2 and may be formed integrally with the outer ring 14b of the cross roller bearing 14. Further, in the present embodiment, the rotational axis of the harmonic reducer 10 is arranged to be vertical. However, the harmonic reducer 10 of the present invention may be arranged in a case where the rotational axis is horizontal or any other posture. Needless to say, it can be used.

[0006]

As described above, according to the present invention, the following effects can be obtained. (1) Since the wave generator is assembled integrally with the harmonic reducer, accuracy is improved. (2) Since the insertion direction of the input shaft can be selected either up or down,
The degree of freedom in designing a mechanism using a harmonic reducer is increased. (3) The coupling between the harmonic reducer and the motor is simple. (4) The number of parts of the turning mechanism of the robot can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a harmonic reducer attached to a turning base of an industrial robot according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a harmonic reducer attached to a turning base of an industrial robot according to the related art.

[Explanation of symbols]

 1: Revolving base 2: Motor base 3: Flange 4: Motor 5: Bearing 6: Motor shaft 7: Input shaft 8: Bolt 10: Harmonic reducer 11: Wave generator 11a: Cam plate 11b: Flexible bearing 11c: Center Shaft 12: Flex spline 13: Circular spline 14: Cross roller bearing 14a: Inner ring 14b: Outer ring 15: Flange 16: Bearing 17a: First outer casing 17b: Second outer casing

Claims (4)

[Claims] 1. A circular spline, a flex spline inserted into the circular spline and meshing with the circular spline, a wave generator inserted into the flexspline, and a first outer fixed to the flexspline. A harmonic reduction device comprising a housing and a second outer housing fixed to the circular spline, wherein the wave generator is supported by the first outer housing via a bearing. Machine. 2. A circular spline, a flex spline inserted into the circular spline and meshing with the circular spline, a wave generator inserted into the flex spline, and a first outer fixed to the flex spline. A harmonic reduction device comprising a housing and a second outer housing fixed to the circular spline, wherein the wave generator is supported by the second outer housing via a bearing. Machine. 3. A fixed part, a circular spline, a flex spline inserted into the circular spline and meshing with the circular spline, a wave generator inserted into the flex spline, and fixed to the flex spline. A first outer housing, comprising a second outer housing fixed to the circular spline, a harmonic reducer fixed to the fixed portion, and a rotating portion fixed to an output shaft of the harmonic reducer. An industrial robot according to claim 1, wherein said wave generator is supported by said first outer casing via a bearing. 4. A fixed part, a circular spline, a flex spline inserted into the circular spline and meshing with the circular spline, a wave generator inserted into the flex spline, and fixed to the flex spline. A first outer housing, comprising a second outer housing fixed to the circular spline, a harmonic reducer fixed to the fixed portion, and a rotating portion fixed to an output shaft of the harmonic reducer. An industrial robot according to claim 1, wherein said wave generator is supported by said second outer casing via a bearing.