Clutches

3.3 Dynamic torque

The torque the clutch must transmit whilst slipping. In most applications it is present for a short time. The time limit is set by the clutch's ability to dissipate the heat generated. Manufacturers help the designer to calculate the heat limit by providing a heat capacity value for the clutch. Given information about the power being transmitted and the speed difference across the clutch, the temperature rise of the clutch, can be calculated. If this exceeds the manufacturer's recommended value, the calculation is repeated with a larger clutch. Related to the speed difference is the time needed to bring both shafts to the same operating speed - this is a function of the inertia of the driven side.