Fluid friction clutch

A fluid friction clutch comprising:

• housing means defining a working chamber means, and a reservoir chamber means,
• primary and secondary parts mounted for relative rotation with respect to each other and exhibiting working surfaces disposed in said working chamber means,
• and fluid connection means for accommodating flow of viscous fluid means from the reservoir chamber means to the working chamber means to control the fluid drive connection between the working surfaces of the primary and secondary parts,
• wherein said reservoir chamber means is a pressure chamber, wherein the fluid connection means opens into the reservoir chamber means at a radial distance from the clutch rotational axis which is larger than the radial distance from the clutch axis to a fluid ring formed in the reservoir means during rotation thereof,
• and wherein said fluid connection means is configured to prevent flow of viscous fluid means from the reservoir chamber means to the working chamber means when the reservoir chamber means is not pressurized,
• and wherein said fluid connection means is configured as a tube which is connected in a pressure sealed manner at intermediate plate means separating the reservoir chamber means and the working chamber means.

A fluid friction clutch comprising:

• housing means defining a working chamber means, and a reservoir chamber means,
• primary and secondary parts mounted for relative rotation with respect to each other and exhibiting working surfaces disposed in said working chamber means,
• fluid connection means for accommodating flow of viscous fluid means from the reservoir chamber means to the working chamber means to control the fluid drive connection between the working surfaces of the primary and secondary parts,
• wherein said reservoir chamber means is a pressure chamber, wherein the fluid connection means opens into the reservoir chamber means at a radial distance from the clutch rotational axis which is larger than the radial distance from the clutch axis to a fluid ring formed in the reservoir means during rotation thereof,
• and wherein the fluid connection means is configured as a bore hole provided as an overflow duct arranged at an intermediate plate means separating the reservoir chamber means and the working chamber means.