Abstract: A system and method for operating a vehicle equipped with an automatic stop and start system is disclosed. The vehicle includes an internal combustion engine, an automatic transmission and a fluid launch device with an impeller disconnect clutch. A controller may initiate an automatic stop or start of the engine under certain operating conditions. During an engine start/stop event, the engine is automatically shut down and the impeller clutch of the fluid launch device may be disengaged to decouple the engine and transmission from the driveline to provide for improved fuel economy and reduced emissions.

Abstract: Methods and systems for improving operation of a vehicle driveline that includes an engine and an automatic transmission with a torque converter are presented. In one non-limiting example, the engine may be stopped while a vehicle in which the engine operates is rolling. A transmission coupled to the engine may be shifted as the vehicle rolls so that vehicle response may be improved if a driver requests an increase of engine torque.

Abstract: A hydraulic control system for an automatic transmission with a torque converter includes two regulator valves controlled by a single variable force solenoid (VFS). A bypass clutch regulator valve increases the pressure to a bypass clutch apply chamber as the VFS pressure increases. A converter charge regulator valve decreases the pressure in a converter charge circuit as the VFS pressure increases. The converter charge circuit is in series with a lubrication circuit. An orifice restricts the flow through these circuits such that they can be supplied from the line pressure circuit rather than a lower priority circuit. In one embodiment, an on/off solenoid opens a flow control valve to bypass the orifice when additional flow is required. In another embodiment, an electric pump supplements the flow in these circuits when required. This later embodiment includes a switch valve such that the electric pump also supports stop/start operation.

Abstract: A system and method for operating a vehicle equipped with an automatic stop and start system is disclosed. The vehicle includes an internal combustion engine, an automatic transmission and a fluid launch device with an impeller disconnect clutch. A controller may initiate an automatic stop or start of the engine under certain operating conditions. During an engine start/stop event, the engine is automatically shut down and the impeller clutch of the fluid launch device may be disengaged to decouple the engine and transmission from the driveline to provide for improved fuel economy and reduced emissions.

Abstract: A system and method for operating an automatic start/stop system in a motor vehicle having an internal combustion engine, an automatic transmission and a torque converter with an impeller disconnect clutch is disclosed. A controller may implement an engine start/stop system by, at appropriate times, stopping engine by halting fuel and restarting engine when propulsion is needed. During an engine start/stop event, the engine is automatically shut down and the impeller clutch of the torque converter may be disengaged to decouple the impeller and the engine to provide for fuel and emissions savings.

Abstract: A transmission includes an input shaft, and a primary drive gear fixed to the input shaft. The primary gear has a first set of gear teeth. An idler gear is disposed in the transmission and has a second set of gear teeth in meshing engagement with the first set of gear teeth. The transmission also includes a transmission-pump drive gear having a third set of gear teeth in meshing engagement with the second set of gear teeth. The transmission-pump drive gear is configured to transmit power from the input shaft to a transmission pump. A power take-off unit is mounted to a case of the transmission and includes a first unit drive gear having a fourth set of gear teeth in meshing engagement with the second set of teeth. The a first unit drive gear is configured to transmit power from the idler gear to the power take-off.

Abstract: A transmission includes a torque converter stator with controllable blade angle. A controller adjust the blades by commanding fluid pressures in hydraulic circuits routed to the stator hub. The controller also adjust the torque capacity of a torque converter bypass clutch by commanding fluid pressures in hydraulic circuits routed to apply and release chambers. Various schemes are presented to multiplex hydraulic circuits to serve multiple functions.

Abstract: A transfer case and transmission are designed to permit the transmission hydraulic control system to control a range selection coupler and a torque on demand clutch in the transfer case. Two pressure circuits are transmitted from the transmission to the transfer case: a high range circuit and a low range circuit. The low range circuit is pressurized to engage low range while the range circuit is pressurized to engage high range. The torque on demand clutch is controlled by whichever of these circuits has the higher pressure. Lubrication is provided to a front section of the transfer case via the transmission output shaft, with the fluid returning to the transmission sump through a drainback passageway. The rear portion of the transfer case has a segregated sump. A control strategy is employed to partially fill front section of the transfer case with fluid in preparation for vehicle towing.

Abstract: A transmission includes a case having a front support that defines a reservoir, and a first passageway in fluid communication with the reservoir. The transmission also includes a torque converter having a bypass clutch having a piston disposed between a balance chamber and an apply chamber. The clutch fixes the turbine to the impeller in response to fluid pressure in the apply chamber exceeding fluid pressure in the balance chamber. The transmission further includes a hollow stator shaft fixed to the front support and a turbine shaft driveably connected to the turbine. The turbine shaft extends through the stator shaft and defines a second passageway in fluid communication with the first passageway and the balance chamber. The reservoir, the first passageway, the second passageway, and the balance chamber are arranged such that fluid travels from the reservoir to the balance chamber when the piston is de-stroked.

Abstract: A hydraulic control system for an automatic transmission with a torque converter includes two regulator valves controlled by a single variable force solenoid (VFS). A bypass clutch regulator valve increases the pressure to a bypass clutch apply chamber as the VFS pressure increases. A converter charge regulator valve decreases the pressure in a converter charge circuit as the VFS pressure increases. The converter charge circuit is in series with a lubrication circuit. An orifice restricts the flow through these circuits such that they can be supplied from the line pressure circuit rather than a lower priority circuit. In one embodiment, an on/off solenoid opens a flow control valve to bypass the orifice when additional flow is required. In another embodiment, an electric pump supplements the flow in these circuits when required. This later embodiment includes a switch valve such that the electric pump also supports stop/start operation.

Abstract: An output shaft of a transmission is fixed to a planetary gearset carrier. Output torque is measured via a surface acoustic wave sensor affixed to a face of the carrier between two adjacent planet gears and radially inside a weld joining the carrier face to an opposite carrier face. In this location, the level of strain at typical transmission output torques produces a level of strain within the measuring range of a surface acoustic wave sensor. The sensor may be powered and signals communicated across an air gap defined by signal rings. Due the stable position and orientation of the carrier, a small, consistent air gap is possible.

Abstract: A transmission includes a case having a front support that defines a reservoir, and a first passageway in fluid communication with the reservoir. The transmission also includes a torque converter having a bypass clutch having a piston disposed between a balance chamber and an apply chamber. The clutch fixes the turbine to the impeller in response to fluid pressure in the apply chamber exceeding fluid pressure in the balance chamber. The transmission further includes a hollow stator shaft fixed to the front support and a turbine shaft driveably connected to the turbine. The turbine shaft extends through the stator shaft and defines a second passageway in fluid communication with the first passageway and the balance chamber. The reservoir, the first passageway, the second passageway, and the balance chamber are arranged such that fluid travels from the reservoir to the balance chamber when the piston is de-stroked.

Abstract: Methods and systems for improving operation of a vehicle driveline that includes an engine and an automatic transmission with a torque converter are presented. In one non-limiting example, the engine may be stopped while a vehicle in which the engine operates is rolling. A transmission coupled to the engine may be shifted as the vehicle rolls so that vehicle response may be improved if a driver requests an increase of engine torque.

Abstract: Methods and systems for improving operation of a vehicle driveline that includes an engine and an automatic transmission with a torque converter are presented. In one non-limiting example, the engine may be stopped while a vehicle in which the engine operates is rolling. A transmission coupled to the engine may be shifted as the vehicle rolls so that vehicle response may be improved if a driver requests an increase of engine torque.

Abstract: A front module housing an electric motor/generator and an engine disconnect clutch for a modular hybrid transmission includes a valve body that houses a hydraulic valve which operates the engine disconnect clutch. The valve body is located at an angle relative to the bottom of the front module, providing fastener clearance for mounting the front module to an internal combustion engine.

Abstract: A transmission includes an input shaft, and a primary drive gear fixed to the input shaft. The primary gear has a first set of gear teeth. An idler gear is disposed in the transmission and has a second set of gear teeth in meshing engagement with the first set of gear teeth. The transmission also includes a transmission-pump drive gear having a third set of gear teeth in meshing engagement with the second set of gear teeth. The transmission-pump drive gear is configured to transmit power from the input shaft to a transmission pump. A power take-off unit is mounted to a case of the transmission and includes a first unit drive gear having a fourth set of gear teeth in meshing engagement with the second set of teeth. The a first unit drive gear is configured to transmit power from the idler gear to the power take-off.

Abstract: A vehicle includes an electric machine, a torque converter and damper, and a controller. The controller is programmed to operate the electric machine to apply a regenerative torque according to a deflection of the damper and a difference between a speed of the electric machine and an output speed of the torque converter.

Abstract: A transmission includes a torque converter with both a variable pitch stator and a bypass clutch. These are controlled in two modes to maintain a target slip speed. In a first mode, the bypass clutch is fully released and slip is controlled by varying the pitch of the stator blades. In a second mode, the stator is held in the tightest position and slip is controlled by varying the torque capacity of the bypass clutch. The target slip is calculates based on a variety of different input signals depending on what type of vehicle maneuver is being performed.

Abstract: A method of starting a vehicle may include providing power to a motor to spin the motor at a speed at least equal to a target engine cranking speed while a clutch configured to couple an engine and motor is open. The method may also include cutting power to the motor in response to the motor achieving the speed, and locking the clutch to couple the rotating inertias of the motor and a transmission with the engine to start the engine.

Abstract: A transfer case and transmission are designed to permit the transmission hydraulic control system to control a range selection coupler and a torque on demand clutch in the transfer case. Two pressure circuits are transmitted from the transmission to the transfer case: a high range circuit and a low range circuit. The low range circuit is pressurized to engage low range while the range circuit is pressurized to engage high range. The torque on demand clutch is controlled by whichever of these circuits has the higher pressure. Lubrication is provided to a front section of the transfer case via the transmission output shaft, with the fluid returning to the transmission sump through a drainback passageway. The rear portion of the transfer case has a segregated sump. A control strategy is employed to partially fill front section of the transfer case with fluid in preparation for vehicle towing.