Abstract: A system for providing a constant flow of cooled hydraulic fluid to a dual clutch assembly of a transmission of a motor vehicle includes a hydraulic fluid cooler, a pressure control valve and a logic valve. The system is also capable of providing additional hydraulic fluid to the dual clutch assembly. The hydraulic fluid cooler provides hydraulic fluid to each clutch of a dual clutch assembly and to a logic valve. The logic valve is operable to divert additional fluid flow to either of the clutches of the dual clutch assembly.

Abstract: The present invention comprehends a plurality of embodiments of a hydraulic control system for various configurations of dual clutch transmissions. The hydraulic control systems all include a regulated source of pressurized hydraulic fluid including an electric pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.

Abstract: Hydraulic control systems for a dual clutch transmission include a regulated source of pressurized hydraulic fluid including an electric pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.

Abstract: 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.

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 valve assembly having a pressure dead band includes a first valve or sleeve slidably disposed within a valve body. A second valve is partially slidably disposed within the first valve and partially slidably disposed in the valve body. A plurality of fluid passages communicate with the valve assembly and provide a first flow of hydraulic fluid and a second flow of hydraulic fluid. A lower threshold of the pressure dead band is defined by the pressure on the combination of the first area of the first valve and the first area of the second valve required to balance the resultant force developed on the second area of the second valve. An upper threshold of the pressure dead band is defined by the pressure on the first area of the second valve required to balance the resultant force developed on the second area of the second valve.

Abstract: A method for controlling a clutch assembly includes controlling an actual clutch fill pressure using open-loop pressure controls when an active fill phase is detected, and using closed-loop pressure controls when the active fill phase is complete or when an overfill condition is detected. The method supplies the actual clutch pressure according to a second set of open-loop pressure controls when a step in commanded clutch pressure is detected. The method monitors a fill pressure and time during the step, and applies the clutch pressure according to the closed-loop pressure controls when either value equals a corresponding threshold value. A clutch assembly has a piston for compressing clutch disks to initiate a shift event, an algorithm for controlling the shift event, and a sensor for determining an actual clutch pressure during the shift phases. The algorithm switches between closed-loop and open-loop pressure controls in response to different shift phases.

Abstract: The present invention comprehends a plurality of embodiments of a hydraulic control system for various configurations of dual clutch transmissions. The hydraulic control systems all include a regulated source of pressurized hydraulic fluid including an electric pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.

Abstract: A transmission of the present invention has an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices include clutches and brakes. A method for controlling the transmission selectively engages the torque transmitting devices in combinations of at least two to establish at least nine forward speed ratios and at least one reverse speed ratio.

Abstract: The present invention comprehends a plurality of embodiments of a hydraulic control system for various configurations of dual clutch transmissions. The hydraulic control systems all include a regulated source of pressurized hydraulic fluid including an electric pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.

Abstract: An automatic transmission includes an input shaft, an output shaft and four planetary gear assemblies each having a first, a second and a third element. The automatic transmission includes six fixed or rigid interconnections: one from a third element of the second planetary gear assembly to a second element of the fourth planetary gear assembly, one from a second element of the third planetary gear assembly to the second element of the fourth planetary gear assembly, one from a third element of the first planetary gear assembly to a second element of the second planetary gear assembly, one from a third element of the third planetary gear assembly to a first element of the fourth planetary gear assembly and one from an element of the second planetary gear assembly to an element of the first planetary gear assembly. The automatic transmission also includes four clutches and three brakes which may be selectively engaged to provide nine, ten or eleven speed transmission 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 flow through the valves to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio. A range selection valve is operable to place the transmission in Park and out-of-Park modes of operation.

Abstract: An automatic transmission includes an input shaft, an output shaft and four planetary gear assemblies each having a first, a second and a third element. The automatic transmission includes six fixed or rigid interconnections: one from a third element of the second planetary gear assembly to a second element of the fourth planetary gear assembly, one from a second element of the third planetary gear assembly to the second element of the fourth planetary gear assembly, one from a third element of the first planetary gear assembly to a second element of the second planetary gear assembly, one from a third element of the third planetary gear assembly to a first element of the fourth planetary gear assembly and one from an element of the second planetary gear assembly to an element of the first planetary gear assembly. The automatic transmission also includes four clutches and three brakes which may be selectively engaged to provide nine, ten or eleven speed transmission operation.

Abstract: A solenoid pump and associated hydraulic circuitry are intended for use in automatic transmissions capable of engine start stop (ESS) operation. In a first embodiment, a solenoid pump provides pressurized hydraulic fluid to respective inputs of two way check valves. The other inputs are provided with controlled hydraulic fluid from a transmission valve body. The outputs of the check valves are provided to those hydraulically operated torque transmitting devices associated with first gear. The solenoid pump is activated when the transmission is in gear and the engine is stopped to maintain hydraulic pressure in those actuators associated with first gear in order that a first gear vehicle launch may be quickly and smoothly achieved when the engine is restarted. A second, similar embodiment provides hydraulic fluid to actuators associated with reverse gear.

Abstract: The present invention comprehends a plurality of embodiments of a hydraulic control system for various configurations of dual clutch transmissions. The hydraulic control systems all include a regulated source of pressurized hydraulic fluid including an electric pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.

Abstract: A hydraulic control system for a automatic transmission includes a plurality of solenoids and valves in fluid communication with a plurality of shift actuators. The shift actuators are operable to actuate a plurality of torque transmitting devices. Selective activation of combinations of the solenoids allows for a pressurized fluid to activate at least one of the shift actuators. The solenoids are configured to provide a forward gear ratio and a reverse gear ratio when the solenoids are deengerized.

Abstract: A hydraulic control system and method for controlling a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies 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 pressure control solenoids and the flow control 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 hydraulic control system and method for controlling a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies 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 pressure control solenoids and the flow control 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: An actuator assembly includes a housing, a piston disposed within a portion of the housing. The piston has a movable range along a working-axis, and separates a first volume and a second volume within the housing. The assembly also includes a biasing feature disposed within the second volume, where the piston is configured to engage the biasing feature within a first portion of the movable range, and configured to not engage the biasing feature within a second portion of the movable range.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies 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 pressure control solenoids and the flow control 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.