EXTREMELY COMPACT HIGH-TORQUE DRIVE WITH SHAPE MEMORY ACTUATORS AND STRAIN WAVE GEAR WAVE DRIVE~reg;

摘要

Strain Wave Gears have been used to achieve high reduction ratios in very compact spaces. They are known to be highly precise and have found widespread use in robot and automation applications. For several years, lightweight Wave Gears made from thermoplastic materials have been on the market. In these gears, the wavelike motion of the so called Flexring is achieved by radial plungers driven by an elliptical core, the Wave Generator. The deformation can also be obtained by other means, like electromagnetic coils (solenoids). In this paper an ultra-compact rotatory stepping drive is presented that is based on a standard Strain Wave Gearbox and powered by Shape Memory Alloys-actuators (SMA). For that purpose the functional principle of this gear type was adopted and enhanced with an actuator component: the deformation of the Flexring is realised by external forces that are provided by SMA-actuators. These transducer materials have gained increasing importance for actuator purposes in the last years. Beside a very high energy density and a large actuator stroke, SMA enable a simple actuator design and offer a high potential for miniaturisation.