Borgwarner Inc.

James Patrick May

Neil E Robb

Darin Lee Gwin

A viscous shear fan drive mechanism for a cooling fan. A moveable valve disk is provided which controls the quantity of fluid in the operating chamber. An electronic actuation system activates piston and shaft members which move the valve disk against the bias of a return spring to open the fill holes, allow fluid communication between the reservoir and working chambers, and allow rotation of the cooling fan. Without activation of the electronic actuation system, the flow of fluid to the working chamber is prevented. A non-magnetic or insulating bushing member adjacent the piston and shaft members prevents the system from sticking in the actuation condition when power is eliminated.

Electronically controlled viscous fan drive with bushing

An electronically-controlled viscous fan drive in which the output drive to the fan is electronically controlled by the movement of viscous fluid from a fluid reservoir and into the operating and working chamber of the coupling during normal operation. A radially balanced valve disk coupled to a spring controls the relative movement of viscous fluid from a fluid reservoir to the working chamber by sealingly engaging and disengaging a fill hole fluidically coupling the fluid reservoir to the working chamber. The clutch plate and cover and body, along with the features defined between the clutch plate and cover and body are cast to the desired size and shape, therein allowing easier and more precise manufacturing and more cost effective manufacturing as compared with traditional designs that are stamped and having machined-in features.

Electronically controlled viscous fan drive having cast channels

An electronically-controlled viscous fan drive having a one-piece accumulator and reservoir located on the top side of the clutch. The accumulator also has a low pressure and high pressure fill hole for allowing movement of viscous fluid from the reservoir to a anti-bleedback chamber and into the operating and working chamber of the coupling during normal operation. A radially balance valve disk having a step up feature coupled to a spring and an actuator electronically controls movement of viscous fluid from the reservoir to the anti-bleedback chamber through the fill holes by energizing or deenergizing the spring based on engine operating conditions. The valve disk may be a one-piece or two-piece design. The accumulator is designed to prevent morning sickness associated with the flow of viscous fluid from the reservoir to the operating chamber during engine off situations.

Growing community of inventors

Jackson, MI, United States of America

James Patrick May