Abstract: A hydraulic control system for actuating at least one torque transmitting device in a transmission includes a sump, a pump in communication with the sump, and an accumulator. A first control device and a second control device control the communication of hydraulic fluid between the pump, the accumulator, and the torque transmitting device.

Abstract: The present invention provides a three position hydraulic piston assembly for a gear ratio change mechanism for a transmission exhibiting reduced gear shift noise. The three position hydraulic piston assembly includes a master piston and motion retarding assemblies that act near both travel limits of the master piston. The master piston includes symmetrical passageways that provide hydraulic fluid flow to small chambers at each end of the piston that are closed off as the piston approaches its travel limits. Hydraulic fluid trapped in the chambers decelerates the piston and is bled off through an orifice allowing the piston to reach its travel limit and quickly and quietly engage a gear ratio.

Abstract: A pressure assisted park servo assembly for an automatic transmission includes a servo or spool valve which receives pressurized hydraulic fluid from various sources including two solenoid valves and transmission ports. The servo valve controls two flows of pressurized hydraulic fluid to a servo assembly to place the transmission in or release it from park. The improved park servo assembly exhibits enhanced operating speed.

Abstract: A system for providing pressurized hydraulic fluid includes a pump. A bypass valve assembly includes an inlet port in communication with the pump and an outlet port in communication with an accumulator. The pump and the accumulator are both in communication with a hydraulic control system that controls, lubricates, and cools a transmission of a motor vehicle. The bypass valve assembly has a valve moveable between at least a two positions. The bypass valve assembly is operable to bypass the accumulator when the vehicle is first started such that the pump charges the hydraulic control system before charging the accumulator. The accumulator provides pressurized hydraulic fluid to the hydraulic control system after vehicle start.

Abstract: The present invention provides a system for shifting or controlling a dual clutch transmission where the transmission may operate in at least a first mode of operation and a second mode of operation. The system includes a controller and a plurality of solenoids in fluid communication with a valve assembly. Selective activation of the solenoids by the controller engages the valve assembly to provide the first mode and the second mode of operation.

Abstract: A hydraulic control system in a transmission includes a source of pressurized hydraulic fluid and a compensator valve in communication with the source of pressurized hydraulic fluid and a torque transmitting device. The compensator valve is operable to allow communication of the hydraulic fluid from the source of pressurized hydraulic fluid to the torque transmitting device to release the torque transmitting device. A regulation valve is in communication with the source of pressurized hydraulic fluid and the torque transmitting device. The regulation valve is moveable between a first position that prevents the hydraulic fluid from communicating with the torque transmitting device and a second position that allows the hydraulic fluid to communicate with the torque transmitting device to engage the torque transmitting device. An override feature is operable to prevent the compensator valve from communicating the hydraulic fluid to the torque transmitting device when the torque transmitting device is engaged.

Abstract: An integrated control valve body and hydraulic pump for an automatic transmission provides improved efficiency and space utilization. The invention includes a control valve body having a plurality of control valves and passageways and an internal cavity having an inlet and an outlet, a pump rotor received within the internal cavity and having a plurality of radially and axially extending slots, radially moveable vanes and a shaft, and means for transferring drive energy from a drive shaft extending between an output of a torque converter and an input of the transmission to the shaft of the hydraulic pump. The means for transferring drive energy may be a pair of chain sprockets and a chain, a pair of spur or helical gears or other inter-axis power transfer components and may effect a speed increase or reduction.

Abstract: The present invention provides a system for shifting or controlling a dual clutch transmission where the transmission may operate in at least a first mode of operation and a second mode of operation. The system includes a controller and a plurality of solenoids in fluid communication with a valve assembly. Selective activation of the solenoids by the controller engages the valve assembly to provide the first mode and the second mode of operation.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of solenoids and valves in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A control system for controlling an axle clutch between two half-axles in a motor vehicle is provided. The control system includes two solenoids and a pressure sensor in communication with a controller and a valve assembly. One of the solenoids provides a flow of fluid to engage the axle clutch. The valve assembly cooperates with another of the solenoids to disengage the axle clutch under certain conditions.

Abstract: A servo system includes pressurized fluid, and one or more fluid control devices (FCD) such as a valve or actuator, with at least one FCD having an element with a variable property that varies in response to a stimulus. The FCD controls a flow rate or pressure transmission of the fluid within the servo system. The element may include an active return spring having a variable stiffness. The servo system may operate as an interlock system for a transmission. A method for moving an output load using a servo system includes providing a first FCD with an active element, connecting an output load to a second FCD, activating the active element with a stimulus to vary a property of the active element, transmitting a force from the pressurized fluid to the second FCD, and moving the output load from a first position to a second position in response to the force.

Abstract: A hydraulic control system for actuating at least one torque transmitting device in a transmission includes a sump, a pump in communication with the sump, and an accumulator. A first control device and a second control device control the communication of hydraulic fluid between the pump, the accumulator, and the torque transmitting device.

Abstract: A hydraulic control circuit for a transmission includes a plurality of solenoids and valves in fluid communication with a plurality of actuators. The actuators are operable to actuate a plurality of torque transmitting devices. Selective activation of the solenoids allows for a pressurized fluid flow to activate at least one of the actuators in order to shift the transmission into a desired gear ratio.

Abstract: The present invention provides a three position hydraulic piston assembly for a gear ratio change mechanism for a transmission exhibiting reduced gear shift noise. The three position hydraulic piston assembly includes a master piston and motion retarding assemblies that act near both travel limits of the master piston. The master piston includes symmetrical passageways that provide hydraulic fluid flow to small chambers at each end of the piston that are closed off as the piston approaches its travel limits. Hydraulic fluid trapped in the chambers decelerates the piston and is bled off through an orifice allowing the piston to reach its travel limit and quickly and quietly engage a gear ratio.

Abstract: A servo system includes pressurized fluid, and one or more fluid control devices (FCD) such as a valve or actuator, with at least one FCD having an element with a variable property that varies in response to a stimulus. The FCD controls a flow rate or pressure transmission of the fluid within the servo system. The element may include an active return spring having a variable stiffness. The servo system may operate as an interlock system for a transmission. A method for moving an output load using a servo system includes providing a first FCD with an active element, connecting an output load to a second FCD, activating the active element with a stimulus to vary a property of the active element, transmitting a force from the pressurized fluid to the second FCD, and moving the output load from a first position to a second position in response to the force.

Abstract: The present invention provides a system for shifting or controlling a dual clutch transmission where the transmission may operate in at least a first mode of operation and a second mode of operation. The system includes a controller and a plurality of solenoids in fluid communication with a valve assembly. Selective activation of the solenoids by the controller engages the valve assembly to provide the first mode and the second mode of operation.

Abstract: A control system for controlling an axle clutch between two half-axles in a motor vehicle is provided. The control system includes two solenoids and a pressure sensor in communication with a controller and a valve assembly. One of the solenoids provides a flow of fluid to engage the axle clutch. The valve assembly cooperates with another of the solenoids to disengage the axle clutch under certain conditions.

Abstract: A hydraulic control circuit for a transmission includes a plurality of solenoids and valves in fluid communication with a plurality of actuators. The actuators are operable to actuate a plurality of torque transmitting devices. Selective activation of the solenoids allows for a pressurized fluid flow to activate at least one of the actuators in order to shift the transmission into a desired gear ratio.

Abstract: A pressure assisted park servo assembly for an automatic transmission includes a servo or spool valve which receives pressurized hydraulic fluid from various sources including two solenoid valves and transmission ports. The servo valve controls two flows of pressurized hydraulic fluid to a servo assembly to place the transmission in or release it from park. The improved park servo assembly exhibits enhanced operating speed.

Abstract: A regulator valve for controlling the pressure of fluid engaging a torque-transmitting mechanism in a transmission includes a valve body forming a valve bore of a plurality of passages. A spool valve slides within the valve body. A check valve selectively opens and closes one of the passages. A spring is disposed in the valve bore and biases the spool valve in one direction. The spool valve, check valve, spring, valve bore and passages are configured to control the pressure fluid provided to the torque-transmitting mechanism and a linearly increasing pressure until a first predetermined pressure is achieved and then at a second constant predetermined pressure greater than the first predetermined pressure, thus combining gradual clutch engagement during shifting with valve boost necessary for static capacity requirements. A method of controlling engagement of the torque-transmitting mechanism is also provided.