摘要 |
A fixed part of a clutch (1) comprises a magnet body (2), a permanent magnet (3), a coil of an electromagnet (5) and a nonmagnetic insert (4). An armature (19) comprises an armature disc (12) which is made up of two concentric rings and is connected firmly in terms of rotation to a driver (18) via an annular spring (11). Between the fixed clutch part (2, 3, 4, 5) and the armature (19) there is an axially fixed but rotatable clutch disc (15) which has a deflector (8), a nonmagnetic intermediate layer (9) with an insert (10) and a hub (17). A nonmagnetic intermediate layer (16) is arranged in the hub (17), concentrically to the axis of the hub. In the deenergised condition of the coil of the electromagnet (5), the magnetic flux lines of the permanent magnet (3) follow a path (26). In the excited condition of the coil, the magnetic flux lines follow a path (22) while the flux lines of the electromagnet (5) follow a path (21). The nonmagnetic intermediate layer (16) and the nonmagnetic insert (4) reduce the magnetic leakage flux to a minimum. A fail-safe clutch or brake with a high torque and a short response time and with small dimensions is thus created. <IMAGE> |