Viscous clutch for cooling fan in IC engine - has bleed hole on periphery of reservoir to provide controlled fluid flow to start fan operation

摘要

The cooling fan is attached to a housing (12) driven by viscous drag from a rotating plate (5) in a narrow chamber. The housing is prevented from rotating by a friction clutch (16,17) which is disconnected by a temperature sensitive control. The reservoir (1) for viscous fluid has a bleed hole/path (3) to the operating chamber to provide a controlled fluid flow to start the fan rotation. The viscous chamber is pumped out by the centrifugal action of the fan, via a pumping port (4) diametrically opposite the bleed hole. ADVANTAGE - Fan is able to reach operating speed in minimum time, simple operating control.