Brake assembly including torque monitor.

摘要

A method is disclosed for monitoring braking torque capability of a brake used for selectively braking a shaft of an exemplary control rod drive. The method includes the steps of rotating the shaft, engaging the brake, torsionally restraining the brake for allowing rotation of the brake up to a predetermined maximum angle, and monitoring the angle for monitoring braking torque capability of the brake. A preferred embodiment of a brake assembly for carrying out the method includes a stationary base (52), a bearing (56) mounted to the base, a brake (62) mounted to the bearing for rotation relative to the base, means (64) for torsionally restraining the brake for allowing rotation of the brake up to the predetermined maximum angle, and means for monitoring the angle. In one embodiment, the torsional restraining means comprises a plurality of springs (104) for providing limited rotation of the brake, and the angle monitoring means comprises a switch which is activated at a predetermined threshold angle of rotation of the brake, or a strain gage which continuously monitors bending strain in the spring for indicating torque-resisting capability of the brake.