Modulating fluid shear coupling.

摘要

A modulating fluid shear coupling apparatus is disclosed herein which comprises a driving member mounted within a working chamber defined by a driven member and rotatable coaxial with the driven member. The driving and driven members include complementary shear surfaces to effect torque transmission between the two members when shear fluid is received between the shear surfaces. The driven member defines a reservoir and includes a passageway leading from the reservoir to the working chamber. At least two annular grooves are defined by the driven member and open into the working chamber adjacent the driving member at different radial positions. The annular grooves and associated passageways leading from the grooves to the reservoir provide for pumping the shear fluid from the working chamber back to the reservoir. Various control means are provided for selectively opening and closing the various passageways to yield several different degrees of coupling between the driving and driven members.