| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a brake or a clutch, each equipped with a wear detection means, which detect a wear limit and let a user etc. know it before wear exceeds an allowable limit upon wear of a friction plate of the brake or the clutch. <P>SOLUTION: The brake comprises an armature 13, an exciting coil 15 for attracting the armature 13 and the friction plate 12 and performs brake operation by using friction force of the armature 13 and the friction plate 12. The brake is constructed to have a detection function of detecting impedance of the exciting coil 15, a determination function of determining the wear limit of the friction plate 12 from the impedance of the exciting coil 15 detected by the detection function and a function of outputting a wear limit signal when the determination function determines that the friction plate is at the wear limit. In this case, the detection function of detecting the impedance of the exciting coil 15 may be a detection circuit which sends an electric current to the exciting coil 15 to an extent of not causing the exciting coil to attract the armature 13 and detects voltage of the exciting coil 15. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
