Strain Wave Gear (also known as harmonic gearing) is a type of mechanical gear system that uses a flexible spline with external teeth, which is deformed by a rotating elliptical plug to engage with the internal gear teeth of an outer spline.

The composition of the harmonic gear transmission device
–Circular spline: rigid internal gear, generally 2 teeth more than the flexspline, usually fixed to the housing.
–Flexspline: a thin cup-shaped metal elastic part with a gear on the outer ring of the opening part, which deforms with the rotation of the wave generator and is usually coupled with the output shaft.
–Wave generator: consists of an elliptical cam and a flexible bearing, which is usually coupled to the input shaft. The inner ring of the flexible bearing is fixed on the cam, and the outer ring can be shaped into an ellipse by the elasticity of the ball implementation.

Working Principle
As a reducer, the Strain Wave Gear are usually driven by a wave generator and output by a flex spline. When the wave generator is installed in the inner ring of the flexspline, the flexspline is forced to undergo elastic deformation and is elliptical; the teeth of the flexible spline of the long axis are inserted into the grooves of the circular spline and fully engaged; the two splines of the short axis The teeth do not touch at all, but disengage. Between engagement and disengagement, the gear teeth are engaged or disengaged.

Parameter Name	Parameter Value
Type	strain wave harmonic
Shaft orientation	coaxial
Performance	zero-backlash
Applications	for servo motors for robots shaft
Other characteristics	mechanical transmission for telecommunications equipment aeronautical parts