Electromagnetically actuable clutch and water pump having an electromagnetically actuable clutch
An electromagnetically actuatable clutch for a water pump in a cooling water circuit of an internal combustion engine, having a drive wheel rotatably mounted relative to the water pump, and an armature disk, which interacts with a coil. The armature disk and a functional component of an eddy current clutch are connected to the drive wheel so that the drive wheel, armature disk and first functional component run synchronously when they rotate. The armature disk can be moved axially with the first functional component by energizing the coil. A second functional component of the eddy current clutch is provided arranged in a fixed fashion on a shaft coupled to the water pump. A friction mechanism is provided between the first and second functional components to provide a frictional locking engagement between the two functional components that is released by energizing the coil.
1. An electromagnetically actuatable clutch for a water pump for an internal combustion engine, comprising:
a drive wheel rotatably mounted relative to the water pump;
an armature disk connected to the drive wheel such that the armature disk is rotationally fixed to the drive wheel while being axially displaceable relative to the drive wheel;
an eddy current clutch comprising
a. a first functional component rotatably fixed to the armature and axially displaceable together with the armature disk;
b. a second functional component fixed to a shaft coupled to the water pump; and
c. a friction mechanism provided between the first and second functional components; and
a coil for moving the armature disk and the first functional component axially away from the second functional component,
wherein the friction mechanism provides a frictional locking engagement between the first and second functional components when the coil is unenergized.
2. A clutch according to claim 1 , wherein one of the first and second functional components comprises a rotational element with permanent magnets.
3. A clutch according to claim 2 , wherein the other one of the first and second functional components comprises a rotational element with an eddy current zone.
4. A clutch according to claim 3 , wherein the eddy current zone is formed in the second functional component.
5. A clutch according to claim 1 , further comprising a cooling element coupled to the second functional component.
6. A clutch according to claim 1 , wherein the friction mechanism comprise a friction lining.
7. A clutch according to claim 1 , further comprising permanent magnets arranged on the first functional component.
8. A water pump comprising the clutch according to claim 1 .