Design of a multi-disc electromechanical modulated dissipator

This paper presents the design of an electrically-actuated, proportional brake that provides a significantly greater torque-to-weight ratio than a magnetic particle brake (considered a benchmark of the state-of-the-art) without sacrificing other characteristics such as dynamic range, bandwidth, or electrical power consumption. The multi-disc brake provides resistive torque through a stack of friction discs which are compressed by a dc-motor-driven ball screw. Unlike nearly all other proportional brakes, which operate in a normally unlocked mode, the brake presented here is designed such that it may be configured in either a normally unlocked or normally locked mode. The latter enables lower electrical energy consumption and added safety in the event of electrical power failure in certain applications. Following the device description, experimental data is presented to characterize the performance of the brake. The performance characteristics are subsequently compared to those of a commercially available magnetic particle brake of comparable size.