Fluid friction clutch

A fluid friction clutch comprising:

• a drivable housing including a working chamber and a reservoir;
• at least one opening between the reservoir and the working chamber configured to provide fluid communication between the reservoir and the working chamber;
• a driven disk supported for rotation in the working chamber;
• and
• a rotor mounted in the reservoir, coupled to the driven disk for rotation about an axis of rotation,
• wherein said rotor comprises a plurality of arms, separated by a plurality of gaps, projecting away from the axis of rotation,
• wherein said rotor including said plurality of arms is substantially planar, and
• wherein said plurality of arms include distal ends and wherein said distal ends are connected by arcuate segments.

In a fluid friction clutch comprising a drivable housing including a working chamber and a reservoir, at least one opening between the reservoir and the working chamber configured to provide fluid communication between the reservoir and the working chamber, and a driven disk supported for rotation in the working chamber, a method of effecting fluid transfer from the reservoir to the working chamber comprising:

• partially filling the reservoir with a working fluid;
• mounting a rotor in the reservoir for rotation about an axis of rotation;
• coupling the rotor to the driven disk;
• and
• driving the rotor in the reservoir to distribute the working fluid around the reservoir and toward the at least one opening,
• wherein the rotor comprises a plurality of arms and a peripheral edge and wherein the plurality of arms are, separated by a plurality of gaps that end at openings in the peripheral edge of the rotor, the arms projecting away from the axis of rotation, and
• wherein mounting the rotor in the reservoir comprises mounting the rotor in the reservoir such that fluid coupling between the rotor and the housing is avoided.