JPH08296704A - Harmonic type decelerating mechanism - Google Patents

Abstract

PURPOSE: To improve deceleration efficiency and reduce generation of heat and action noise by forming an initial stage gear on an input shaft rotating integrally with a wave generator and making a driving motor rotator shaft small gear provided with different centers engage with the initial stage gear. CONSTITUTION: Regarding a harmonic type decelerating mechanism provided with an internal gear 1 retained in a box body, and a flexible spline 2 formed with an external gear whose module is as same as that of the internal gear 1 and having less number of teeth, a wave generator 3, which is composed of a rotation plate 3-1 and a roller group 3-2, is integrally assembled with an initial stage gear 4 and journalled to a shaft 6-1 above an output shaft 6. The initial stage gear 4, which is integrally formed with the rotation plate 3-1, is geared into a small gear 5-1 of a driving motor rotator shaft arranged with different centers. Thus the initial gear 4 is rotated at a low speed by the driving motor 5 and noise and generation of heat caused by the rotation of the wave generator 3 are reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a harmonic reduction mechanism driven at high speed.

[0002]

2. Description of the Related Art FIG. 2 is a cross-sectional view of an example of a conventional harmonic reduction mechanism, which is an internal gear 1 fixed to a housing.
And a flexible flexspline 2 provided on the inner peripheral surface thereof, and a wave generator 3 for pressing the inner peripheral surface of the flexspline 2 to engage the internal gear 1 and the flexspline 2 with each other. ing. The wave generator 3 includes a rotating plate 3-1 and a roller group 3-2 held by the rotating plate 3-1.
Is fixedly connected to the rotor shaft 5-1 'of the drive motor 5. This type of reduction mechanism has a speed ratio of internal gear 1
Torque transmission is performed by changing the engagement position of the two gears by the rotation of the wave generator 3 depending on the difference in the number of teeth between the flexspline 2 and the flexspline 2. As described above, the rotary plate 3-constituting the wave generator 3 is used. 1 is the input shaft 5-1 '
As a result, the inner peripheral surface of the flexspline 2 is naturally rotated at the same speed as the speed of the rotor of the drive motor. The roller group 3-2 held by the rotary plate 3-1 also rolls at high speed in synchronization with the rotation of the rotary plate 3-1. The movement of the engagement portion of the gear due to the rotation of the wave generator 3 naturally produces a gear meshing sound, and the noise increases as the speed increases.

[0003]

SUMMARY OF THE INVENTION The conventional structure as described above has a small size and a high power consumption because the deceleration efficiency is low and the operation sound is high when driving by a high speed electric motor in which the rotating speed of the rotating plate and hence the wave generator is high. In addition to impairing the advantage of obtaining the reduction gear ratio, heat generation due to high-speed sliding of the tooth surface is large, and particularly in the case where the flexspline is formed by resin molding, strength is also reduced.

[0004]

A harmonic reduction mechanism according to the present invention is a drive motor in which a first-stage gear is formed on an input shaft that rotates integrally with a wave generator, and the first-stage gear is arranged at a different center. Is configured to engage with the rotor shaft pinion.

[0005]

[Operation] In the above configuration, the rotation speed of the input shaft is reduced by the speed ratio between the rotor shaft small gear and the first stage gear with respect to the rotor of the drive motor, and therefore the rotation speed of the wave generator can be reduced. The meshing efficiency between the flex spline and the internal gear is greatly improved, the operation noise is small, and the heat generation is reduced.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment according to the present invention. In this embodiment, a wave generator 3 composed of a rotary plate 3-1 and a roller group 3-2 is a shaft portion extending integrally with an initial stage gear 4 from an output shaft 6. It is rotatably supported by 6-1. The fact that the wave generator 3 is in contact with the inner peripheral surface of the flexspline 2 and is involved in the engagement with the internal gear 1 is no different from the prior art. And the above-mentioned rotary plate 3-1
The rotatable first stage gear 4 which is integral with the above is engaged with the small gear 5-1 of the rotor shaft of the drive motor arranged in a different center.

Since the first-stage gear 4 rotates at a low speed with respect to the drive motor 5, the noise and heat generation due to the rotation of the wave generator 3, which has been a problem of the harmonic reduction mechanism as described above, is obviously improved.

Further, the rotor shaft pinion 5-1 of the drive motor 5
A speed ratio between the first stage gear 4 and the first stage gear 4 is arbitrary, and a rotor that is usually easy to process and manufacture is premised on the combination of the internal gear 1 and the flexspline 2 which are difficult to deal with in various aspects such as mold maintenance. It is easy to obtain various reduction ratios by arbitrarily selecting the small shaft gear 5-1 and the first stage gear 4.

[0009]

EFFECTS OF THE INVENTION The harmonic reduction mechanism according to the present invention has various reductions in speed by improving the deceleration efficiency, reducing heat generation and operating noise, and optionally selecting the rotor shaft small gear and the first stage gear which are easy to machine and manufacture. There is an advantage that it is easy to obtain the reduction ratio of.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of an example of a harmonic reduction mechanism according to the present invention.

FIG. 2 is a cross-sectional view of a main part of an example of a harmonic reduction mechanism according to the related art.

[Explanation of Codes] 1 Internal Gear 2 Flex Spline 3 Wave Generator 3-1 Rotating Plate 3-2 Roller Group 4 First Stage Gear 5 Drive Motor 5-1 Rotor Shaft Small Gear 5-1 'Rotor Shaft 6 Output Shaft 6 -1 Output shaft extension 7 Bearing

Claims (3)

[Claims] 1. An internal gear, which is held in a housing and forms an internal gear, and a flexspline, which is flexible and forms an external gear having the same number of modules as the internal gear and a small number of teeth. A wave generator that engages the internal gear and the flexspline at an axially symmetric radial major axis portion; and a so-called harmonic reduction mechanism having an output shaft at the center of the flexspline, integrated with the wave generator. First-stage gear is formed on the input shaft that rotates in a positive manner, and the first-stage gear is configured to engage with the rotor shaft small gear of the drive motor arranged at a different center from the first-stage gear. Reduction mechanism. 2. The wave generator has two rotating plates connected and held so as to face each other, and a roller group rotatably arranged on a roller shaft having both ends thereof held by the rotating plate. The harmonic reduction mechanism according to claim 1, wherein 3. The harmonic reduction mechanism according to claim 1, wherein the first-stage gear that is integral with the wave generator is rotatably supported by a shaft portion that extends from the output shaft.