The strain wave gear, also known as the "harmonic drive", is a gearing component that is compact, light, and produces no backlash as well as exceptional positioning accuracy, torque density and repeatability. It is an indispensable component for the reliable and accurate operation of light industrial robots and manipulators.
Strain Wave Gear consists of three internal elements – the flexspline, the circular spline and the wave generator. The elasticity properties of the flex-spline and the teeth differential between the flexspline and the circular spline result in its unique reduction characteristics.
It comes in various form factors, including component sets, simple contained assemblies and complete gear units. Cup, hat, solid and hollow input shaft configurations give engineers true freedom in design.
Dimensions are interchangeable against industry standards, making it easier to implement in leg-acy equipment.
Operating Principle:
When the wave generator is put inside the flex spline, the flex spline is forced into an elliptical shape that causes the teeth of the flex spline to engage with the teeth of the circular spline at two opposite regions across the major axis of the ellipse. For every 180-degree clockwise rotation of the wave generator, the flex spline teeth are advanced counterclockwise by one tooth in relation to the circular spline. Each complete clockwise rotation of the wave generator results in the flex spline moving counterclockwise by two teeth from its original position relative to the circular spline. Because the gear teeth are always fully engaged in a region along the major axis, these gearheads have zero backlash and a high torque-carrying capacity.
Strain Wave Gear offers the following advantages:
High precision: As multiple teeth engage simultaneously at two 180° symmetric positions, the errors of the pitch of gear teeth and cumulative errors of the pitch of teeth have an average influence on rotation precision, contributing to very high position precision and rotation precision.
Large drive ratio: The single-stage harmonious drive device has a simple structure with a drive ratio from 50:1 to 160:1. Therefore, three basic components on a single axis can realize a high drive ratio.
High load capacity: In strain wave gear systems, the engagement between teeth is a kind of surface contact. As many teeth engage with each other at the same time, the load of each unit is small, which means the load capacity is higher than other drive forms.
Compact and lightweight: Its volume and weight are reduced significantly compared with normal gear devices, and therefore the size is small, and the weight is light.
High drive efficiency and long service life.
High stability with no impact and little noise.
Robotics, Machine Tool, Medical Equipment,
Semiconductor Manufacturing, Satellite, Solar
Communications and Assembly Automation applications
