초록 ▼

A viscous fan clutch (10) is typically employed in a fan drive mechanism within a truck or automobile. A shaft (12) driven by the engine, rotates a clutch member (24) within the fan drive. The clutch member is arranged for fluid engagement with a cover assembly (38) for the transmission of torque th

A viscous fan clutch (10) is typically employed in a fan drive mechanism within a truck or automobile. A shaft (12) driven by the engine, rotates a clutch member (24) within the fan drive. The clutch member is arranged for fluid engagement with a cover assembly (38) for the transmission of torque thereto when the fluid is disposed in an operating chamber (70) defined by complementary shear surfaces (30, 31, 56, and 57) in the clutch and cover. During the relative rotation between the clutch and cover, fluid is pumped from the operating chamber to primary (76) and secondary (77) fluid storage chambers. A fluid temperature responsive control valve (190) provides for selective communication between the storage chambers and the operating chamber to effect modulation of the total fluid flow whereby quasi dual speed operation of the clutch is achieved. Upon receipt of a signal from a control circuit (146), a first measure of viscous fluid (from the primary storage chamber) flows rapidly into the operating chamber to effect a step speed increase. Subsequently, a second measure of viscous fluid (from the secondary storage chamber) flows slowly into the operating chamber to effect a second, gradual speed increase. In the preferred embodiment the valve operates in response to sensed engine liquid coolant temperature.

대표청구항 ▼

A viscous fluid clutch comprising: first and second members mounted for relative rotation about a common axis; shear surfaces disposed on said first and second members and forming an operating chamber therebetween; fluid storage means disposed adjacent said operating chamber; means operative to gene

A viscous fluid clutch comprising: first and second members mounted for relative rotation about a common axis; shear surfaces disposed on said first and second members and forming an operating chamber therebetween; fluid storage means disposed adjacent said operating chamber; means operative to generate a circulating flow of viscous fluid between said chamber and storage means; first flow control means operative to selectively establish a relatively large flow rate of said fluid between said storage means and said operating chamber; and second flow control means operative to selectively establish a relatively small flow rate of said fluid between said storage means and said operating chamber.