ELECTRONICALLY CONTROLLED VISCOUS FAN DRIVE

摘要

PROBLEM TO BE SOLVED: To provide a viscous fan drive eliminating a part causing leakage and reducing a machining cost. SOLUTION: This electronically controlled viscous fan drive has an accumulator 59 having a low pressure and high pressure fill hole 114 for allowing a viscous fluid to flow from a reservoir to an anti-bleedback chamber and into an operating chamber and a working chamber of a coupling during normal operation. A radially balance valve disk 31 having stepped structure coupled to a spring and an actuator electronically controls the movement of the viscous fluid from the reservoir 35 to the anti-bleedback chamber through the fill hole 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. COPYRIGHT: (C)2004,JPO