摘要 |
<p>A cooler bypass valve, located in a hydraulic circuit between the discharge side of a torque converter and lubrication circuit, includes a valve spool urged by feedback pressure acting in opposition to the force of a compression spring to a bypass cooling mode position where the converter discharge fluid flow is connected to the lubrication circuit bypassing the oil cooler. The bypass valve includes a viscosity-sensitive pressure divider, which includes a series arrangement of a laminar orifice and a sharp-edged orifice located between the converter discharge and an oil sump. As oil temperature increases, flow through the laminar orifice produces a control pressure in opposition to the feedback pressure and additive to a spring force, which combine to move the valve spool to a cooling mode position where substantially all of the converter discharge is directed through the oil cooler. In a predetermined temperature range, the valve maintains a position where a portion of the converter discharge is directed to the oil cooler, and the residual to the lubrication circuit.</p> |