Patent ID: 7047797
Filing Date: 2006-05-23
Classification: G01L,G01M

Abstract:
1. A method for detecting wear in a frictionally locking clutch or brake, the clutch or brake having at least one electrically excitable coil through which an electric current passes, at least one element to effect frictional locking with at least one mating element, the element or the mating element being axially movable and having at least one airgap between the element and the mating element when the clutch or the brake is open, comprising changing said airgap when the clutch or the brake opens or closes, measuring the electric current through the electrically excitable coil when a voltage across the coil changes, evaluating at least some measured values by means of data processing equipment, comparing a time at which at least one notch or one peak of the electric current during an excitation process and/or during a de-excitation process of the electrically excitable coil with a stored reference time, and inferring the wear from the difference between the times.