Abstract: An automatic transmission is comprised of a housing and a hub rotatable about a shaft at differing speeds and having an axial assembly gap therebetween. The axial assembly gap defines an annular flow path in fluid communication with a source lubrication path and a lubrication-requiring mechanism. A lubrication control device is disposed in the annular flow path. The device includes a washer in constant contact with the housing and having a radial slot to permit a prescribed flow of lubricant through the annular flow path to the lubrication-requiring mechanism. The device further includes a belleville spring wherein a small diameter end is in contact with the hub and a large diameter end is piloted by a seating on the washer, wherein the belleville spring provides spring adjustability to accommodate the variable axial assembly gap.

Abstract: A cast iron cylinder liner for an engine has a body with a radial upper flange and a generally cylindrical wall extending axially from an inner portion of the flange. An arcuate fillet is formed at a juncture between the upper flange and an exterior of the cylindrical wall. To strengthen the juncture of thin wall liners, for example with wall thickness less than 2.5 mm, a portion adjacent the fillet is laser hardened to a selected depth of the wall, thus increasing resistance to stresses created in the wall when the liner is installed and operating in an engine.

Abstract: An improved method of operation for a motor vehicle automatic transmission determines a vehicle speed for purposes of selecting a desired transmission gear at least in part based on the wheel speeds of the vehicle. If the vehicle is being operated in a two-wheel drive mode, the vehicle speed is determined based on an average of the speeds of the un-driven wheels; if the vehicle is being operated in a four-wheel drive mode, the vehicle speed is determined based on the lowest of the four wheel speeds. Optionally, the wheel speeds are only used to determine vehicle speed if the Reverse range of the transmission has been engaged within a specified time interval, and otherwise the vehicle speed is determined based on an output speed of the transmission.

Abstract: An engine control for a motor vehicle powertrain coordinates engine speed and torque limiting during automatic transmission range changing so as to provide both vehicle rocking capability and adequate protection for the transmission. A transmission controller temporarily limits the engine speed to a predetermined value on each transition to or from the forward or reverse ranges, and superimposes continuous engine speed and torque limitations when an abusive rocking maneuver is detected. An abusive rocking maneuver is detected when the driver commands at least a specified number of successive range shifts during a predetermined time interval, and the speed and torque limitations are imposed until range shifting is discontinued for at least a calibrated period of time.

Abstract: A method is provided for controlling an output/input speed ratio of a continuously variable transmission (CVT) plant including primary and secondary pulleys actuated by primary and secondary pressures (Pp,Ps,), respectively, which generate forces to move the pulleys and adjust a corresponding belt, thereby adjusting the output/input ratio. The method includes calculating a desired force ratio for the CVT plant. Desired primary and secondary pressures (PP,PS) are then determined based, in part, upon the calculated desired force ratio, and the desired PS and PP signals are sent to the CVT plant to control operation of the CVT plant. An actual speed ratio is calculated based on measurements of input and output speed from the CVT plant.

Abstract: A vehicle transmission, for example a CVT transmission, is provided with a decoupling device between an engine output shaft and a vehicle driveline. The decoupling device in one embodiment includes a clutch assembly which is fixed to a shaft coupled to the transmission output and engageable with a driveline through a piston arrangement. The piston can be urged against the force of a spring by fluid pressure to cause engagement of the clutches of the clutch assembly and thereby to couple engine torque to the vehicle driveline. When fluid pressure is released, the spring urges the piston to a position in which the clutches of the clutch assembly are disengaged, so as to disengage the engine output from the vehicle driveline. In the disengaged state, the vehicle can be towed.

Abstract: An internal combustion engine comprises an aluminum alloy engine block housing pistons in cylinders and having a lower face including an upper semi-circular bearing surface. A lower bearing support has a lower semi-circular bearing surface to complement the upper semi-circular bearing surface in the engine block to define a crankshaft bore to rotatably support an iron alloy crankshaft. The lower bearing support is formed of a single aluminum-silicon alloy having a coefficient of thermal expansion comparable to the iron alloy crankshaft to promote a consistent clearance between the lower bearing support and the crankshaft. Such an aluminum-silicon alloy is comprised of approximately 33-35% by weight silicon and the balance is aluminum.

Abstract: A cooling system has a system bypass to reduce parasitic losses in an internal combustion engine. The system bypass has a diverter valve actuated by a control module to selectively control the amount of coolant flow through the engine without regard to the speed of the water pump. As less coolant is needed to cool the engine, the diverter valve directs more coolant through the bypass to be recirculated to the water pump. The energy absorbed by the water pump is reduced by the reduced coolant flow, which increases the efficiency of the system and reduces engine parasitic losses.

Abstract: A torque-transmitting mechanism has first and second housing members, which are interconnected by a plurality of friction members. The torque-transmitting mechanism also includes an apply piston, which has an apply head slidably disposed within one of the housings and a spring body portion, which is effective to urge the apply head out of engagement with the friction members. The apply head is urged into engagement with the friction members through the application of pressure to an apply chamber formed between the apply head, the spring body, and the one housing. Upon release of the pressure within the apply chamber, the spring body enforces retraction of the apply head and disengagement of the torque-transmitting mechanism.

Abstract: A transfer gear assembly includes a transfer gear rotatably supported directly by a tapered roller bearing and thrust bearing. A tapered snap ring is positioned in a circumferential groove on a hub to provide a preload on the tapered roller bearing and thrust bearing. The tapered roller bearing and thrust bearing each may include only a single race.

Abstract: A hydraulically-operated clutch for an automatic transmission includes a clutch housing assembly with a clutch pack positioned therein. A movable piston is supported in the clutch housing assembly and defines an expandable chamber between the piston and clutch housing assembly. Pressurized fluid is provided to the expandable chamber to effect movement of the piston between engaged and disengaged positions with respect to the clutch pack. The piston and clutch housing assembly are configured such that only a small portion of the expandable chamber is pressurized when the piston is in the disengaged position, thereby providing improved response time for movement of the piston to the engaged position.

Abstract: A multi-mode torque-transmitting assembly includes a plate-supporting element having an axis, and a plate connected to the plate-supporting element such that the plate is axially movable with respect to the plate-supporting element between a first position and a second position in response to applied axial forces. Furthermore, the assembly includes a movement-inhibiting member in sufficient cooperation with the plate for selectively inhibiting axial movement of the plate. The movement-inhibiting member inhibits movement of the plate from the first position in response to a first axial force, and allows movement of the plate toward the second position in response to a second axial force greater than the first axial force, such that the assembly is operable in more than one mode.

Abstract: A powertrain includes a rotary input member such as an engine crankshaft, a torque coupling such as a hydraulic torque converter, a drive plate, such as a flex plate or spider, connecting the input member to the coupling, and an annular generator rotor having an electrical power annulus, such as an annular induction member extending around the coupling, and a mounting ring fixed to the power annulus and including means extending inward for securing the mounting ring to the coupling and to the drive plate. Several embodiments of mounting rings and assemblies are disclosed which improve methods for assembly of the powertrain.

Abstract: A shim carrier assembly for optionally retaining shims therein, wherein the carrier has at least three intercontiguated planar portions with holes or slots therein, such that a fastener may be inserted through the holes or slots for aiding in the shimming of fastened components.

Abstract: A braking clutch is provided for a transmission which includes a transmission housing and a plurality of planetary gear members. The braking clutch includes a floating caliper movably supported on the transmission housing. An apply hub is actuated by an electric motor. A rotor is operatively connected to one of the planetary gear members and has a portion extending between the floating caliper and the apply hub to enable selective braking of rotation of the rotor by frictionally engaging the portion of the rotor between the floating caliper and apply hub, thereby braking rotation of the planetary gear member.

Abstract: A torque converter clutch control valve has a single valve element for controlling the fluid distribution to and from a torque converter and clutch assembly to establish clutch engagement and disengagement as well as torque converter operation. The control valve has one position for supplying fluid to release the clutch and simultaneously feed the torque converter, and another position to supply a pressure controlled fluid to engage the clutch. A force motor control valve is provided to control the pressure level of the clutch engagement pressure.

Abstract: An electric motor driven pump has a regulator valve for establishing a system pressure within a predetermined pressure range. The regulator valve has three bias pressures and a spring force imposed thereon. One of the bias pressures assists the spring to increase the system pressure and the other two bias pressures either balance the spring and one bias pressure or lower the system pressure. The one bias pressure is established by an electro-hydraulic control mechanism as a function of operating parameters in a powertrain which uses the fluid pressure from the pump. One of the other bias pressures is equal to system pressure and the last bias pressure is available when a predetermined drive condition is requested in the powertrain. A first electrical switch is activated by fluid pressure from the regulator valve if the system pressure is below the demanded pressure and a second electrical switch is activated by fluid pressure from the regulator valve if the system pressure is above the demanded pressure.

Abstract: A clutch assembly for a transmission is configured to selectively interconnect a first rotatable member with a second rotatable member by engagement of a clutch pack. The clutch assembly includes a compensator and a piston which is axially moveable with respect to the compensator and configured to selectively abut and engage the clutch pack to interconnect the first and second rotatable members. A clutch housing encloses the piston, compensator and clutch pack. A piston cavity is formed between the housing and piston to receive fluid from a clutch apply feed orifice to actuate the piston. A compensator cavity is formed between the compensator and piston to receive fluid from a compensator feed orifice.

Abstract: A piston assembly is provided for use in an engine. The piston assembly includes a piston body including a crown with a skirt extending from the crown. The skirt has an exterior surface. The exterior surface has a surface finish in a wave form with peaks and valleys, and having a roughness total between approximately 6 and 8 micrometers. The roughness total is defined as the difference between the highest peak and lowest valley within an assessment length. The surface finish has an approximate peak-to-peak distance between 0.18 and 0.23 mm within the assessment length. A composite coating is provided over the exterior surface.

Abstract: An apparatus for controlling the clutches in an automatic vehicle transmission includes a series of electric motors attached to the transmission housing, each of which has a motor shaft with a gear attached to it. A torque-to-thrust mechanism is driven by the driving gear and includes a thrust element that imparts a linear force to the apply plate of a clutch. Also included is a sensing system that allows for sensitive control of the torque-to-thrust mechanism which facilitates smooth engagement and disengagement of the clutch.