Abstract: A device is disclosed for measuring torsional vibrations superimposed on rotating equipment such as a shaft. The device may be fastened to a rotating shaft by a collar and includes a sensor array comprising two or more accelerometers measuring the radial acceleration of the sensor array and the tangential acceleration of the sensor array. The gravitational component of the accelerometer signals is identified either by isolation in one of the signals, or by comparing two or more signals. From the tangential and radial acceleration signals, a torsional vibration amplitude is calculated from the ratio of the tangential acceleration and the radial acceleration. The radial acceleration is further used to determine the average velocity of the sensor array. The tangential acceleration may further be integrated to obtain the angular velocity of the sensor array, or further integrated to obtain the angle rotated through.

Abstract: A viscous damper has an inertial mass in the form of a tubular member that is applicable for dissipating (removing) destructive torsional vibration in power transmitting shaft assemblies. A viscous fluid contained between moving surfaces is sheared, thereby producing frictional heat which is then allowed to transfer across the moving surfaces to the ambient surroundings. Surfaces of the inertial mass and housing are arranged with respect to each other to provide high shear rate and energy dissipation (damping) is obtained within a small volume.

Abstract: A torque-release coupling can be remotely reset after an over-torque condition. A threshold torque may be adjusted while the coupling is running. A pressure of pressurized fluid adjusts a force required to release a detent mechanism that holds a torque transmitting member in engagement across an interface between moving parts.