Harmonic drive

Harmonic Drive is a strain wave gear which can improve certain characteristics compared to traditional gearing systems. Harmonic Drive is trademarked by the Harmonic Drive company.

The strain wave gear was invented in 1957 by C.W. Musser. The advantages include: reduced backlash, compactness and light weight, high gear ratios, reconfigurable ratios within a standard housing, good resolution and excellent repeatability (linear representation) when repositioning inertial loads, high torque capability, and coaxial input and output shafts. High gear reduction ratios are possible in a small volume (a ratio from 30:1 up to 320:1 is possible in the same space in which planetary gears typically only produce a 10:1 ratio).