Gm Global Technolgoy Operations, Inc.

Borgwarner Inc.

Tsunlock A Yu

William J Vukovich

Melissa M Koenig

Larry A Pritchard

Philip John Francis

Todd R Berger

Scott B Pollack

Thad Kopp

Alan Lee Brace

Bruce T Levy

Edward J Greenan

A hydraulic clutch assembly for a motor vehicle driveline is provided. The clutch assembly comprises an input member, and output member and a friction clutch pack operably disposed therebetween for controlling torque transfer. A first fluid circuit contains hydraulic based fluid at a first pressure and is in fluid communication with the friction clutch pack for lubrication thereof. A second fluid circuit is in fluid communication with the first fluid circuit for replenishing the second fluid circuit with the hydraulic based fluid at a second pressure that is less than the first pressure. The clutch assembly further comprises a motor and a gear train. A first piston is in fluid communication with the second fluid circuit for delivering the hydraulic based fluid thereto A second piston is translated by the hydraulic based fluid displaced by the first piston to actuate the friction clutch pack.

Hydraulic clutch assembly for a motor vehicle driveline

A power transmission has a hydraulic control from which oil is distributed to various transmission components, a cooler and reservoir. A flow direction control valve is disposed in the distribution system to direct oil in transit to the reservoir during cold operation and to a transmission lubrication circuit or cooling circuit during normal operating temperatures.

Flow control for oil in transit

In a neutral to drive shift timing control mechanism, a flow control arrangement is utilized in an electro-hydraulic control system for controlling a clutch fill period of a neutral to drive shift sequence. The hydraulic control system provides a pressure pulse of predetermined time which opens a valve to permit fluid flow to bypass an accumulator feed orifice to pressurize the clutch apply cylinder and piston to a value substantially equal to the piston return spring force without providing excess flow to the accumulator. The clutch apply pressure is then permitted to increase at a more normal rate which is controlled by the accumulator. The engagement time is determined so that the pulse time can be adjusted if the neutral to drive shift is not within a predetermined time range.

Neutral to drive shift time control

An improved control method for properly coordinating a double transition upshift. The state changes of the various clutches of the transmission are sequenced in relation to a dynamic measure of the transmission speed ratio so as to provide consistent high quality shifting. Closed-loop pressure controls are employed in conjunction with the sequencing to ensure timely shift completion.

Double transition upshift control for an automatic transmission

An improved control method for properly coordinating a double transition downshift. The state changes of the various clutches of the transmission are sequenced in relation to a dynamic measure of the transmission speed ratio so as to provide consistent high quality shifting. Adaptive pressure controls are employed in conjunction with the sequencing to compensate for variability.

Double transition downshift control for an automatic transmission

The torque capacity of a torque converter clutch is controlled with a two-state directional valve and a single solenoid operated pressure control valve. In operation, the directional valve is spring biased to a release state in which converter feed pressure is directed to a passage between the clutch plate and the converter input shell to release the clutch and feed the converter. The return fluid from the opposite (apply side) of the clutch is routed through the directional valve to a low pressure fluid cooler. A control pressure generated by the solenoid operated valve develops a hydraulic bias which opposes the spring bias. When the hydraulic bias is sufficiently great, the directional valve shifts to a control state in which the solenoid operated valve controls the pressure supplied to either the apply or release side of the clutch to control its torque capacity.

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Saline, MI, United States of America

Tsunlock A Yu