Electro-hydraulic control system with three-position dog clutch actuator valve
AssigneeGM Global Technology Operations LLC
InventorsCharles F. Long, Bryan H. Hagelskamp
Life of this patent
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Abstract
An electro-hydraulic control system is provided for a transmission, which is preferably a countershaft transmission, that has a three-position dog clutch actuator valve to control the position of a three-position dog clutch. At least one of the positions of the dog clutch actuator valve is established by pressurized fluid directed to the dog clutch actuator valve by two logic valves, both of which are controlled to direct pressurized fluid elsewhere in the hydraulic control system, as well.
Claims16
An electro-hydraulic control system for a transmission having a three-position dog clutch selectively movable between a reverse, a neutral and a forward position, comprising:
- a dog clutch actuator valve selectively movable between three different positions corresponding with and controlling movement of the dog clutch between the reverse, neutral and forward positions;
- wherein the dog clutch actuator valve includes a spool valve and a plug valve independently movable with respect to one another;
- a first and a second logic valve each selectively movable between a first position and a second position to control flow of pressurized fluid to a first location and a second location, respectively;
- and
- wherein movement of any of the first and second logic valves controls movement of the dog clutch actuator valve.
An electro-hydraulic control system in combination with a transmission, comprising:
- an electronic controller;
- seven torque-transmitting mechanisms, including a three-position dog clutch;
- four trim systems, each trim system having a solenoid valve energizable in response to the electronic controller and a trim valve operable to selectively provide pressurized fluid in response to the solenoid valve;
- three logic valves each movable to direct the flow of pressurized fluid from a respective different one of the trim valves to at least one of the torque-transmitting mechanisms for engagement thereof;
- a dog clutch actuator valve movable between three positions to control the position of the dog clutch;
- wherein the dog clutch actuator valve is positioned in fluid communication between one of the trim valves and one of the logic valves so that said one of the logic valves is movable in response to the position of the dog clutch actuator valve;
- and
- wherein engagement of the torque-transmitting mechanisms in different combinations provides nine forward speed ratios and at least one reverse speed ratio.
An electro-hydraulic control system for a transmission, comprising:
- a three-position dog clutch actuator valve;
- at least two logic valves each selectively movable between first and second positions to direct pressurized fluid to the dog clutch actuator valve;
- wherein one of the three positions of the three-position dog clutch actuator valve is established via pressurized fluid directed from the two logic valves;
- an electronic controller
- first and second solenoid valves each energizable via the electronic controller for moving said at least two logic valves;
- and
- wherein the pressurized fluid directed from the logic valves latches the three-position dog clutch actuator valve in said one of the three positions when the electronic controller is inoperable due to an electronic power failure.
Dependencies are inferred from the claim text.