Operating Principle Torque Converters Within a closed circuit, a centrifugal pump accelerates an operating fluid which, in turn, drives a turbine. The torque produced by a motor is thus transmitted steplessly and without friction. A guide wheel connected with the housing absorbs the torque differential between input and output shafts. By changing the amount or the flow direction of the operating fluid, input and output torques can be varied and the converter may be used as a control device. Design torque converter