How does a harmonic reducer work

When harmonic is used as a reducer, usually in the form of active wave generator, fixed circular spline and flex spline output.

When wave generator is installed into the inner circle of flex spline, it forces flex spline to produce elastic deformation and to become elliptical, so that flex spline teeth at the long axis are inserted into gear groove of circular spline, which becomes a fully engagement state; while at the short axis, the gear teeth of both flex spline and circular spline are completely untouched and in a separation state. The process between engagement and separation is in the state of meshing in or meshing out. When wave generator rotates continuously, it forces flex spline to deform, which makes the teeth of the two splines change their working state during the process of meshing in, engagement, meshing out and separation, resulting in the so-called staggering teeth movement, thus realizing the movement transmission between wave generator and flex spline.