| 摘要 |
<p>A failsafe clutch for driving a shaft (24) e.g. of a power steering pump (22), comprises a rotor (44) fixed to the shaft (24) and axially spaced from a relatively rotatable body (e.g. a pulley) (70) on which is mounted a axially movable magnetic plate (90) having friction material (96) urged by springs (98) into engagement with the rotor (44). Disengagement of the magnetic plate (90) from the rotor (44), and therefore of the clutch is obtained by energising a stationary electromagnet (100) comprising two coils (106a, 106b) connected in parallel to disengage the clutch, and then in series to hold the clutch disengaged.</p> |
