Gm Global Technolgoy Operations, Inc.

Ajit Singh Grewal

Vijay A Neelakantan

Daryl A Wilton

Bret M Olson

Leonid Basin

Carlos E Marin

Jesse B Bradley

Micheal P Portell

A hydraulic control system includes a hydraulic pump driven by an electric motor, a solenoid valve having an output that controls the positions of a pressure regulator valve and a third, stator shift valve. The solenoid valve is a normally high, variable force solenoid valve which provides a control signal to the second and third valves. The second, pressure regulator valve is a multiple port valve which controls hydraulic fluid flow both to a transmission oil cooler (ATOC) and to an exhaust port, thereby maintaining a desired system pressure. The third, stator shift valve is also a multiple port valve and it controls fluid flow to the stator of the electric pump motor to provide cooling and to a dog clutch of the transmission to disengage it.

Hydraulic control system

A shift mechanism for a dual clutch transmission employs a rotating barrel cam having at least three tracks which are engaged by and translate at least three associated cam followers. The cam followers extend from shift fork bodies which slide on rails and include shift forks which bi-directionally translate at least three synchronizer clutches which engage at least five forward gears or speeds and reverse. A single electric motor and gear train drive the barrel cam.

Barrel cam shift mechanism

A vehicle powertrain includes an engine capable of being selectively turned on and turned off, a transmission operatively connected to the engine, and a hydraulic control system including a pump in fluid communication with the transmission. The pump is operatively connected to the engine for supplying fluid to the transmission when the engine is on, wherein the pump is idle when the engine is off. The hydraulic control system additionally includes an accumulator arranged to accumulate the fluid when the engine is on. The accumulator is also controlled to accumulate fluid when the engine is on, to retain the fluid when the engine is turned off, and to discharge the fluid to the transmission when the engine is restarted.

Hydraulic control for a vehicle powertrain

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Canton, MI, United States of America

Ajit Singh Grewal