The wave generator is made of two separate parts: an elliptical disk called a wave generator plug and an outer ball bearing. More complex versions have a fourth component normally used to shorten the overall length or to increase the gear reduction within a smaller diameter, but still follow the same basic principles. The mechanism has three basic components: a wave generator (2 / green), a flex spline (3 / red), and a circular spline (4 / blue).
The strain wave gearing uses the elasticity of metal. It can provide gear reduction but may also be used to increase rotational speed, or for differential gearing. Strain wave gearing is commonly used in robotics and aerospace. 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).ĭisadvantages include a tendency for 'wind-up' (a torsional spring rate) in the low torque region. good resolution and excellent repeatability (linear representation) when repositioning inertial loads,.