Design of a Two-Speed Load Adaptive Variable Transmission for Energetic Optimization of an Accessible Prosthetic Hand

Abstract

This work proposed the design of a simple, robust, and inexpensive motion transmission for hand prostheses. The main challenge to be solved is to generate not only fast movements for the closing of the fingers during the grasping but also important forces to hold these objects. A two-speed load adaptive variable transmission is introduced to solve this challenge using a planetary gear train to reduce the speed and a selector clutch with wrap spring. The main properties of these two systems are recalled and a guideline is introduced to reach the user requirement. Finally, an application example is presented and the proposed prototype is analyzed.