Transmission Hydraulic Control System

摘要

An automatic transmission uses 6 shift elements applied in combinations of four to establish ten forward speed ratios and a reverse speed ratio. The automatic transmission uses a hydraulic control system to control engagement of the six elements, control engagement of a torque converter bypass clutch, control engagement of a parking pawl, and to provide fluid for a hydrodynamic torque converter and for lubrication. The parking pawl is disengaged in response to engagement of two of the six shift elements and remains disengaged in response to engagement of other shift elements. A single valve controls several different functions associated with the two-pass torque converter. Pressurized fluid is provided by a variable displacement engine driven pump and also by an electric pump. A priority valve reduces lubrication flow when other fluid demands are high as indicated by the pump displacement control circuit.

主权项

1. A transmission comprising:
a fluid coupling configured to draw fluid from a converter release circuit and exhaust fluid to a converter apply circuit when a pressure in the converter release circuit exceeds a pressure in the converter apply circuit; a bypass clutch configured to transmit torque with a torque capacity based on a difference between the pressure in the converter apply circuit and the pressure in the converter release circuit; and a single regulator valve configured to switch between first and second states based on a pressure in a control circuit such that
in the first state fluid is routed from a flow source to the converter release circuit, and fluid is routed from the converter apply circuit to a lubrication circuit, andin the second state fluid is routed to the converter apply circuit at a pressure based on the pressure in the control circuit, fluid is routed from the flow source to the lubrication circuit, and fluid is exhausted from the converter release circuit.