Viscous fluid clutch

摘要

A viscous fluid clutch includes a housing rotatably mounted to a drive shaft and a clutch plate attached to the drive shaft. These relatively rotatable members have a fluid shear space therebetween and cooperable with a fluid medium in the shear space to provide a shear-type fluid drive therebetween. The housing includes a reservoir, an operating chamber and a pump outlet opening communicating between the operating chamber and the reservoir. An annular wall is secured at its inner and outer peripheral edges to the clutch plate and includes an annular bend between the outer and inner peripheral edges to define an annular auxiliary reservoir in cooperation with the clutch plate. The housing has an annular recess accommodating the annular bend. The annular recess is defined by a cylindrical inner surface. This cylindrical inner surface and the opposed surface of the annular bend define therebetween an annular passage communicating with the operating chamber. A plurality of blades are arranged in this passage for urging viscous fluid to move toward the operating chamber out of the annular passage.