Allison Transmission, Inc.

Gm Global Technolgoy Operations, Inc.

Jeffrey E Shultz

Scott E Mundy

Jared S Shattuck

Bruno Re

Scott T Kluemper

Mark A Rushing

Charles Francis Long

John P Kresse

Randall S Conn

Peter G York

Darren J Weber

Phillip F McCauley

Edmond M Etchason

Mark A Rains

Bryan H Hagelskamp

Jill Ann Hampton

Vickie M Rushing, Legal Representative

Bradley L Mc Cafferty

Joseph K S Johansson

John Byerly

Transmission systems, control systems for vehicles, and methods of operating vehicles are disclosed herein. A transmission system for a vehicle includes a transmission and a heat exchanger. The transmission is configured to receive rotational power supplied by a drive unit and provide the rotational power to a load in use of the transmission system. The heat exchanger is fluidly coupled to the transmission and configured to cool a sump of the transmission to manage transmission oil temperature in use of the transmission system. The transmission includes a control system having a plurality of sensors and a controller coupled to the plurality of sensors that has a processor and a memory device coupled to the processor.

Transmission systems to control heat exchangers to manage transmission sump temperature

Transmissions, control systems for transmissions, and methods of operating transmissions are disclosed. A transmission includes an input shaft, an output shaft, one or more clutches, and a control system. The input shaft is configured to receive rotational power supplied by a drive unit. The output shaft is coupled to the input shaft and configured to provide rotational power supplied to the input shaft to a load. The one or more clutches are coupled between the input shaft and the output shaft to selectively transmit rotational power between the input shaft and the output shaft in one or more operating modes of the transmission. Each of the one or more clutches is selectively engageable in response to one or more fluid pressures applied thereto. The control system is configured to control operation of the one or more clutches to select the one or more operating modes of the transmission.

Transmission control systems to adjust clutch pressure and torque based on grade

Transmissions, control systems for transmissions, and methods of operating transmissions are disclosed herein. A transmission includes an input shaft, an output shaft, one or more clutches, and a control system. The input shaft is configured to receive rotational power supplied by a drive unit. The output shaft is coupled to the input shaft and configured to provide rotational power supplied to the input shaft to a load. The one or more clutches are coupled between the input shaft and the output shaft to selectively transmit rotational power between the input shaft and the output shaft in one or more operating modes of the transmission. Each of the one or more clutches is selectively engageable in response to one or more fluid pressures applied thereto. The control system is configured to control operation of the one or more clutches to select the one or more operating modes of the transmission.

A device, system, and method for controlling transmission torque to provide hill ascent and/or descent assistance to a vehicle includes applying a clutch hold pressure to one or more clutches of a transmission to lock an output shaft of the transmission to resist roll-back of the vehicle. The clutch hold pressure is applied based on one or more of a transmission output speed signal, an engine throttle signal, and a vehicle brake signal.

Device and method for controlling transmission torque to provide hill ascent and/or descent assistance

The present invention provides a method of selecting and implementing a shift schedule for a transmission in a vehicle that includes an output speed sensor and a controller. The method includes measuring output speed with the output speed sensor and comparing the measured output speed to an output speed threshold. The controller receives throttle percentage and compares the throttle percentage to a throttle threshold. The method also includes calculating output acceleration and transmission gear ratio with the controller. The shift schedule is selected based on the measured output speed, calculated output acceleration, calculated transmission gear ratio, and throttle percentage.

Acceleration based mode switch

A device, system, and method for controlling transmission torque to provide hill ascent and/or descent assistance to a vehicle includes applying a clutch hold pressure to one or more clutches of a transmission to lock an output shaft of the transmission to resist roll-back of the vehicle. The clutch hold pressure is determined as a function of the tractive effort of the vehicle and is applied based on one or more of a transmission output speed signal, an engine throttle signal, and a vehicle brake signal.

Device, system, and method for controlling transmission torque to provide hill ascent and/or descent assistance using road grade

The present disclosure provides a method for increasing a volume of hydraulic fluid in a reservoir of a transmission. The method includes providing a retarder mounted to the transmission, an accumulator including an internal cavity, a piston disposed in the internal cavity of the accumulator, a solenoid, a valve, and a controller. The method also includes enabling the solenoid from an off state to an on state, transferring fluid pressure from the valve to the piston, and moving the piston from a first position to a second position in the internal cavity. The method further includes discharging an amount of hydraulic fluid from the internal cavity of the accumulator to the reservoir and increasing the volume of hydraulic fluid in the reservoir.

System for adjusting fluid volume in a transmission and method thereof

Embodiments which selectively engage a motor with auxiliary equipment and a final drive assembly of the motor vehicle are disclosed. A transmission of such a motor vehicle may include a transmission input shaft to receive power from the motor, a transmission output shaft, and clutches and associated gears that define power delivered by the transmission output shaft based upon power received by the transmission input shaft. An auxiliary gearbox may include a transmission input gear associated with the transmission output shaft, an equipment output gear to power the auxiliary equipment, and a drive output gear to power the final drive assembly. The motor vehicle may further include a transmission control module to engage the transmission input gear with the equipment output gear by transitioning among locking the transmission output shaft, disengaging the clutches to reduce torque on the transmission output shaft, and placing the transmission in an unlocked neutral state.

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Zionsville, IN, United States of America

Jeffrey E Shultz