| 摘要 |
<p>A control valve is provided for a fluid-operated clutch. Specifically, the control valve controls fluid to the fluid-operated clutch of a vehicle cooling fan. The control valve disengages the clutch to disconnect the fan from an internal combustion engine of the vehicle when coolant temperature is low and engages the clutch to operate the fan when the coolant temperature rises to a predetermined value. The control valve has a central passage with three bores and a valve spool with three sealing members associated with the bores. Fluid is supplied under pressure to the valve and always acts in opposite directions on two of the sealing members to provide a balanced condition for the valve spool even with fluctuations in the inlet pressure of the fluid. The control valve utilizes a temperature-responsive device to move the valve spool, with the device being readily adjustable to achieve operation at desired coolant temperatures.</p> |
