How does the harmonic reducer work?

update:2022-04-05

abstract:Before assembly, the flex wheel and its inner hole are circular. When the wave generator is installe...

Before assembly, the flex wheel and its inner hole are circular. When the wave generator is installed in the inner hole of the flex wheel, since the length of the wave generator is slightly larger than the diameter of the inner hole of the flex wheel, the flex wheel is braced into an ellipse, forcing the flex wheel to form an ellipse. The wheel meshes with the fixed rigid wheel in the direction of the long axis of the ellipse, and separates in the direction of the short axis.

Since the rigid wheel is fixed, when the wave generator rotates counterclockwise, the flexible wheel rotates clockwise. When the wave generator rotates continuously, the long and short shafts of the flex wheel and the positions of "engaged" and "engaged out" are constantly changing. Turning out and disengaging, in this way, engage, engage, engage, disengage, engage, engage... Reciprocating cycle, forcing the flex wheel to rotate continuously.

During the rotation of the flexible wheel with the wave generator, when one of the teeth meshes with a tooth of the rigid wheel to mesh with the tooth on the rigid wheel again, the flexible wheel rotates exactly once, and at this time the wave generator rotates. For many turns, the ratio of the number of revolutions of the wave generator to the number of revolutions of the flexible wheel (1 revolution) is the reduction ratio of the planetary reducer, so the reduction ratio is very large. During the whole movement process, the deformation of the flexible wheel is a continuous simple harmonic shape on the expansion diagram of the circumference of the flexible wheel. Therefore, this transmission is called harmonic gear transmission.

The harmonic reducer can be divided into: single wave, double wave and three waves according to the number of its mechanical waves, of which the commonly used is double wave transmission. In the harmonic drive, the difference between the number of teeth of the rigid wheel and the flexible wheel should be equal to the integer multiple of the mechanical wave number, which is usually equal to the wave number.

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