| 摘要 |
<p>A magnetic slip clutch (26, 415) is disclosed, which may be fully uncoupled, fully coupled, or coupled in a modulated manner for transmission of variable torque. One use of the clutch is to provide a variable speed drive of a fan (24, 424) having fan blades (20, 420) for use with an internal combustion engine (12) such as on a vehicle (10). A torque transfer between a clutch driving element (202, 416, 616) and a driven element (200, 418, 618) is by a controller and a circuit (30, 70, 702, 722) that modules the electrical power to control the magnetic field between the driving element (202, 416, 616) and the driven element (200, 418, 618). The preferred driving element (202, 416, 616) carries electromagnetiC coils (300-310, 438, 638) that are energized to develop a magnetic field for coupling to the driven element (200, 418, 618) that has magnetic elements preferably in the form of magnetizable pole pieces (260, 270, 429, 629) thereon. The clutch includes an electrical generator (435, 601) to generate its electrical power. The generator (435, 601) receives a trickle supply of current, and it generates an AC current; and a rectifier (710-720) converts this to DC current for the electromagnetic clutch coils (300-310, 438, 638). If desired, a commutating system (749, 751, 722) can be used to provide timed pulses of current to the clutch coils (300-310, 438, 638) to provide more torque in the direction of clutch rotation.</p> |
