The figure shows the force-displacement-diagram on the friction pairs of coil and diaphragm springs over the lining wear.
While in the coil spring clutch, the axial force drops linearly over the wear displacement, the diaphragm spring's axial force shows a distinct maximum in the operating area. At an approximately similar maximum axial force, this curved characteristic of the diaphragm spring results in a significantly larger wear displacement compared to the coil spring without falling short of a pre-determined minimum axial force.