| 摘要 |
A coolant pump includes a pump frame, a driving wheel driven by an engine, a pump wheel driven by the driving wheel, and a clutch which couples the driving wheel with the pump wheel. The clutch comprises a friction surface arranged at the driving wheel, and a clutch disc which corresponds to the friction surface. The clutch disk is connected with and co-rotates with the pump wheel, and is axially shiftable between an engaged and a disengaged position. An axial pretension spring pretensions the clutch disc into the disengaged position. A permanent magnet forces the clutch disc into the engaged position. An electromagnet, when energized, generates a polarization which is opposite to a polarization of the permanent magnet to reduce a total magnetic attraction force of the permanent magnet with respect to the clutch disc and to thereby push the clutch disc into the disengaged position via the pretension spring. |
