Abstract: A transmission includes a case, a clutch pack, a piston. The case defines a bore that transitions along a step from a first to a second diameter. The piston is disposed within the bore. The piston has first and second seals that engage the case along the first and second diameters, respectively. The piston defines a chamber that is encompassed by the piston, the case, the first seal, and the second seal. The piston is configured to engage a clutch pack when hydraulic fluid is channeled into the chamber.

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 friction element assembly for a transmission of a motor vehicle includes a set of plates and friction members. A piston assembly is configured to apply a force to the set of plates and friction members. The friction element assembly also includes a housing with a mounting groove; a pressure plate having first and second edges; and a snap ring positioned in the mounting groove. The snap ring is positioned such that first edge of the pressure plate contacts the snap ring and the second edge of the pressure plate extends across a portion of the snap ring. The snap ring is L-shaped and includes a leg portion that contacts the second edge of the pressure plate when the piston assembly applies a force to the set of plates and friction members.

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 friction element assembly for a transmission of a motor vehicle includes a set of plates and friction members. A piston assembly is configured to apply a force to the set of plates and friction members. The friction element assembly also includes a housing with a mounting groove; a pressure plate having first and second edges; and a snap ring positioned in the mounting groove. The snap ring is positioned such that first edge of the pressure plate contacts the snap ring and the second edge of the pressure plate extends across a portion of the snap ring. The snap ring is L-shaped and includes a leg portion that contacts the second edge of the pressure plate when the piston assembly applies a force to the set of plates and friction members.

Abstract: A planetary gearset is provided in a transmission for a vehicle. The planetary gearset includes a carrier that rotates about the axis. Tone wheels can be used as part of a speed-sensing mechanism in which the tone wheel includes surface features on an outside surface, and a speed sensor senses the surface features as they rotate about the axis and past the speed sensor. The tone wheel is connected to the carrier via a press-fit or interference-fit. To do so, the tone wheel includes legs or flanges that extend inward from an inner surface of the tone wheel. The legs or flanges flex as the tone wheel is pressed onto the carrier. The legs or flanges securely attach the tone wheel to the carrier.

Abstract: A park-by-wire system uses a single spring to bias the system towards park and to permit a ratcheting feature which delays the engagement of park until vehicle speed drops below a threshold. A cam slides with respect to a rod. A stop on the rod limits travel in one direction. The spring biases the cam toward the stop but compresses as necessary to allow the cam to move during ratcheting operation. The spring reacts against the housing. Acting through the cam and the stop, the spring biases the rod toward the park position. The design limits the number of components that move during ratcheting operation. Specifically, the rod and actuator do not oscillate during ratcheting operation.

Abstract: Stress-relief grooves are provided in a pressure plate of a friction element assembly in a motor vehicle comprising a transmission. The friction element assembly includes a piston assembly provided for applying a force to a set of plates and friction members to cause torque to be transmitted through the friction element assembly. A pressure plate is supported by the housing and held in place by a snap ring mounted in a mounting groove. The pressure plate includes a first side facing the set of plates and friction members and a second side having at least one stress-relief groove configured to reduce stress in the housing at the mounting groove.

Abstract: A planetary gearset is provided in a transmission for a vehicle. The planetary gearset includes a carrier that rotates about the axis. Tone wheels can be used as part of a speed-sensing mechanism in which the tone wheel includes surface features on an outside surface, and a speed sensor senses the surface features as they rotate about the axis and past the speed sensor. The tone wheel is connected to the carrier via a press-fit or interference-fit. To do so, the tone wheel includes legs or flanges that extend inward from an inner surface of the tone wheel. The legs or flanges flex as the tone wheel is pressed onto the carrier. The legs or flanges securely attach the tone wheel to the carrier.

Abstract: A friction element assembly for a transmission of a motor vehicle includes a set of plates and friction members. A piston assembly is configured to apply a force to the set of plates and friction members. The friction element assembly also includes a housing with a mounting groove; a pressure plate having first and second edges; and a snap ring positioned in the mounting groove. The snap ring is positioned such that first edge of the pressure plate contacts the snap ring and the second edge of the pressure plate extends across a portion of the snap ring. The snap ring is L-shaped and includes a leg portion that contacts the second edge of the pressure plate when the piston assembly applies a force to the set of plates and friction members.

Abstract: A vehicle transmission includes a transmission shaft, a friction element assembly mounted on the transmission shaft, a piston assembly for actuating the friction element assembly, a snap ring for retaining the friction element assembly and a mounting groove formed in the transmission shaft. The snap ring is installed into the mounting groove by expanding the snap ring and then allowing the snap to contract and enter the mounting groove. The mounting groove is located such that the snap ring could exit the mounting groove upon expansion of the snap ring due to a centrifugal force. Accordingly, various arrangements are provided to prevent the snap ring from leaving the mounting groove after installation.

Abstract: Stress-relief grooves are provided in a pressure plate of a friction element assembly in a motor vehicle comprising a transmission. The friction element assembly includes a piston assembly provided for applying a force to a set of plates and friction members to cause torque to be transmitted through the friction element assembly. A pressure plate is supported by the housing and held in place by a snap ring mounted in a mounting groove. The pressure plate includes a first side facing the set of plates and friction members and a second side having at least one stress-relief groove configured to reduce stress in the housing at the mounting groove.

Abstract: A transmission planetary gear assembly, having: a carrier housing with axial orifice; a pinion shaft fitted through the axial orifice; a first fastener configured to axially secure the pinion shaft with respect to the carrier housing at one end of the shaft; and a second fastener configured to axially secure the pinion shaft with respect to the carrier housing at another end of the shaft.

Abstract: A clutch assembly is disclosed that combines a positively engaging dog clutch and one way clutch. The two devices are design such that the one way clutch never interferes with the engagement or disengagement of the dog clutch. In one embodiment, the one way clutch transmits torque in particular rotational positions and the dog teeth are circumferentially placed such that they do not engage in any of these positions. In another embodiment, the dog clutch piston, to which the teeth are secured, is permitted to rotate enough to accommodate any interference between dog teeth during engagement. In either embodiment, the teeth faces that transmit torque in the same direction as the one way clutch may be angled such that torque in that direction tends to disengage the dog clutch.

Abstract: A transmission planetary gear assembly, having: a carrier housing with axial orifice; a pinion shaft fitted through the axial orifice; a first fastener configured to axially secure the pinion shaft with respect to the carrier housing at one end of the shaft; and a second fastener configured to axially secure the pinion shaft with respect to the carrier housing at another end of the shaft.

Abstract: A clutch assembly is disclosed that combines a positively engaging dog clutch and one way clutch. The two devices are design such that the one way clutch never interferes with the engagement or disengagement of the dog clutch. In one embodiment, the one way clutch transmits torque in particular rotational positions and the dog teeth are circumferentially placed such that they do not engage in any of these positions. In another embodiment, the dog clutch piston, to which the teeth are secured, is permitted to rotate enough to accommodate any interference between dog teeth during engagement. In either embodiment, the teeth faces that transmit torque in the same direction as the one way clutch may be angled such that torque in that direction tends to disengage the dog clutch.

Abstract: The present disclosure relates to a piston-actuated clutch assembly for a transmission. Interconnecting members are integrated into a pressure plate of the clutch assembly. The interlocking members are configured to selectively interlock the piston and the pressure plate. The location of the interlocking members reduces wear on the piston and other transmission components.

Abstract: A parking assembly 10 is provided for use in combination with a vehicle of the type having a park gear 12 and a shifter or shifting assembly 14 which is operatively used to select between several “gears” or vehicle operating modes. The parking assembly 10 includes a selectively and pivotally movable parking pawl member 20, a park rod assembly 22, and a servo mechanism 24 which selectively actuates park rod 22. The servo mechanism 24 is controlled by use of a controller 30 which monitors several sensors 32, 34 and which allows the park event to be calibrated based upon various selectable vehicle conditions or attributes.

Abstract: A parking assembly 10 is provided for use in combination with a vehicle of the type having a park gear 12 and a shifter or shifting assembly 14 which is operatively used to select between several “gears” or vehicle operating modes. The parking assembly 10 includes a selectively and pivotally movable parking pawl member 20, a park rod assembly 22, and a servo mechanism 24 which selectively actuates park rod 22. The servo mechanism 24 is controlled by use of a controller 30 which monitors several sensors 32, 34 and which allows the park event to be calibrated based upon various selectable vehicle conditions or attributes.

Abstract: A park lock mechanism for an automatic transmission includes a park apply rod for selectively engaging and disengaging a park pawl with a park gear. The park apply rod is actuated by a plate member having a slot formed therein. The slot defines a cam portion and a lost motion portion whereby the cam portion causes the park apply rod to move longitudinally so as to actuate the park pawl. The lost motion portion limits longitudinal travel of the park apply rod in any gear other than park. A reaction member is also used to limit the degrees of freedom of the park apply rod.