I. Composition of Harmonic Drive Device

Steel Wheel: The rigid internal gear usually has two more teeth than the flexible wheel and is typically mounted on the housing.

Flexible Ring: A thin cup-shaped metal elastic component with a gear on the outer circumference of the opening, which deforms with the rotation of the wave generator and is usually connected to the output shaft.

The Wave Generator: Composed of an elliptical cam and a flexible bearing, it is typically connected to the input shaft. The inner race of the flexible bearing is fixed to the cam, while the outer race can be elastically deformed into an elliptical shape through ball bearings.

Harmonic Gear Reduction Principle

The transmission principle of harmonic drives is based on the relative motion between the flexible ring, steel ring, and wave generator, primarily achieved through the controllable elastic deformation of the flexible ring to transmit motion and power.

The elliptical cam within the wave generator rotates inside the flexible wheel, causing deformation. When the teeth of the flexible wheel and the steel wheel engage at the ends of the long axis of the elliptical cam in the wave generator, the teeth of the flexible wheel at the ends of the short axis disengage. The teeth between the long and short axes of the wave generator are in a semi-engagement state, gradually entering engagement across different segments of the circumference of the flexible and steel wheels, which is known as engagement. When they are in a state of gradually disengaging from engagement, it is called disengagement.

As the wave generator rotates continuously, the flexible wheel undergoes continuous deformation, causing the two wheels' teeth to keep changing their original working states through four movements—engaging, meshing, disengaging, and separating. This generates misalignment movement, realizing the transmission of motion from the active wave generator to the flexible wheel.

Harmonic Drive Features

1. Simple structure, compact size, and light weight

2. Wide transmission ratio range

3. More teeth engaged simultaneously

4. High carrying capacity

High-motion accuracy

6. Smooth operation

High Transmission Efficiency

8. Good coaxiality

9. Achievable transmission of motion and power to confined spaces

10. Achieves High-Speed Motion Capability

11. Facilitates differential transmission implementation