JPH0623175Y2 - Motor with reducer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a motor with a speed reducer, and more particularly to a motor having a harmonic speed reducer.

[Prior Art] Conventionally, a motor provided with a harmonic speed reducer has a long axial length because the speed reducer is coupled to the shaft end of the motor.
In order to eliminate the drawback, there is a structure in which a flexible rotary cylinder made of an elastic material having a tooth profile on the outer periphery, which is a component of a harmonic speed reducer, is provided in the space between the stator and the rotor of the motor (for example, JP-A-51-17512).

[Problems to be Solved by the Invention] However, the length of the air gap between the stator and the rotor is half the difference between the major axis and the minor axis of the elliptical shape when the flexible rotary cylinder is deformed. The length is the sum of the thickness of the flexible rotary cylinder. This results in a relatively large magnetic resistance for a small motor, which is a drawback that causes a reduction in output.

[Means for Solving the Problems] The present invention includes a stator, a rotor, a void formed therebetween, a circular spline having inner teeth on its inner circumference, and an outer tooth on one end of its outer circumference. A flexible rotary cylinder provided with an output shaft at the other end and made of a non-magnetic elastic material provided in the gap, and one end attached to the output shaft and the other end attached to a bracket via a bearing for rotation. A support shaft that supports the child and an elliptical wave generator that is fixed to the support shaft so as to contact from the inner diameter side of one end of the flexible rotary cylinder are provided. The number of teeth is smaller than the number of teeth, and when the flexible rotary cylinder is deformed and formed into an elliptical shape, the inner circumference of the stator is a conical curved surface in the motor with a harmonic reducer in which the inner teeth and the outer teeth mesh with each other at the major axis. The outer circumference of the rotor is formed with an elliptical conical surface It was done.

[Operation] The shape of the surface perpendicular to the axis of the rotor is elliptical, although the ratio of the major axis to the minor axis changes depending on the axial position, and the inner circumference of the stator is also the length of the opposing portion of the rotor. It is formed into a conical curved surface having a diameter proportional to the length of the shaft. Therefore,
The gap in the long axis of the rotor becomes the smallest by adding a slight gap that does not touch the thickness of the flexible rotary cylinder. The average air gap length of the entire motor is extremely smaller than that of the conventional example.

[Embodiment] An embodiment of the present invention shown in the drawings will be described.

FIG. 1 is a side sectional view of an embodiment of the present invention, in which inner teeth 11
A ring-shaped circular spline 1 having an external tooth 21 at one end and an output shaft 3 fixed at the other end,
In addition, the flexible rotary cylinder 2 made of a non-magnetic elastic material is provided, and as shown in FIG. 2, the number of teeth between the inner teeth 11 and the outer teeth 21 is smaller than that of the outer teeth 21 according to the reduction ratio. When the flexible rotary cylinder 2 is deformed and formed into an elliptic shape, the inner teeth 11 and the outer teeth 21 are engaged with each other by the long shaft portion 22 thereof. A stator 4 is fixedly provided to the frame 41 on the outer circumference of the flexible rotary cylinder 2, and the inner circumference of the stator 4 is flexible when the flexible rotary cylinder 2 is deformed into an elliptical shape.
Depending on its axial position, the curved surface forms a part of a conical shape having a diameter approximately equal to the length of the major axis of the facing portion. That is, the inner circumference of the stator 4 is formed into a conical curved surface having a large diameter on the circular spline 1 side and a small diameter on the output shaft side. A rotor 5 is provided inside the stator 4 with the flexible rotary cylinder 2 sandwiched between the one end and the output shaft 3
The other end is fixed to the support shaft 7 mounted on the anti-load side bracket 42 and the output shaft 3 via bearings 6 and 6 '. An elliptical wave generator 8 is provided on the inner diameter side of the flexible rotary cylinder 2 at the position of the outer teeth 21 so as to contact the inner diameter of the flexible rotary cylinder 2, and is fixed to the support shaft 7. The outer circumference of the rotor 5 has substantially the same shape as the elliptical shape of the wave generator 8 on the wave generator 8 side as shown in FIG. 3 (b), and the output shaft 3 side has a flexible rotation as shown in FIG. 3 (c). It is formed with a curved surface so as to have a circular shape slightly smaller than the inner diameter of the cylinder 2. That is, the shape of the cross section perpendicular to the axis of the rotor 5 faces the flexible rotary cylinder 2 when the flexible rotary cylinder 2 is deformed into an elliptical shape with the major axis A and the minor axis B as shown in FIG. It has an elliptical shape similar to the cross section at the position, and the outer periphery of the rotor 5 is formed into a substantially conical elliptic conical surface as shown in FIG. 3 (a). A load side bracket 43 supports the output shaft 3 via a bearing 9.

Therefore, the shape of the surface perpendicular to the axis of the rotor 5 is elliptical, and the gap between the inner side of the stator 4 and the long axis portion 22 of the rotor 5 is the thickness of the flexible rotary cylinder 2 and the flexible rotary cylinder 2. Cylinder 2 is stator 4
And a gap that does not come into contact with the rotor 5 is added.

[Advantages of the Invention] As described above, according to the present invention, since the gap length between the stator and the rotor can be reduced, the gap magnetic flux density is increased, and the output per weight is increased. There is an effect that can be provided.

[Brief description of drawings]

1 is a front sectional view showing an embodiment of the present invention, FIG. 2 is a front sectional view, FIGS. 3 (a), 3 (b) and 3 (c) are explanatory views of a rotor, and FIG. It is explanatory drawing which shows the cross section of a rotating cylinder. 1 ... Circular spline, 11 ... Inner teeth, 2 ... Flexible rotary cylinder, 21 ... Outer teeth, 3 ... Output shaft, 4 ... Stator, 5 ... Rotor, 7 ... Support shaft, 8: Wave generator

Claims (1)

[Scope of utility model registration request] 1. A stator, a rotor, a void formed between them, and a circular spline having internal teeth on its inner circumference,
Outer teeth are provided at one end of the outer circumference and an output shaft is provided at the other end,
And a flexible rotating cylinder made of a non-magnetic elastic material provided in the gap, one end to the output shaft, the other end to the bracket is attached to the bracket through a bearing, and a support shaft for supporting the rotor, An elliptical wave generator fixed to the support shaft by contacting from the inner diameter side of one end of the flexible rotary cylinder is provided, and the number of internal teeth is smaller than that of external teeth according to a reduction ratio, When the flexible rotary cylinder is deformed and formed into an elliptical shape, in the motor with a harmonic reducer in which the inner teeth and the outer teeth mesh with each other at the major axis portion, the inner circumference of the stator is formed into a conical curved surface, A motor with a reducer, wherein the outer periphery of the child is formed into an elliptical conical curved surface.