Abstract: A transmission assembly includes a housing, an input shaft driveably engaged with a drive source and being rotatably supported in the housing, and an output shaft rotatably supported in the housing. A hydrostatic transmission component is disposed within the housing and is drivingly engaged with the input shaft. A mechanical transmission component is disposed within the housing and is drivingly engaged with the input shaft. The hydrostatic transmission component and the mechanical transmission component are drivingly engaged with the output shaft. The hydrostatic transmission component is moveably mounted within the housing and is axially moveable relative to the input shaft.

Abstract: A transmission assembly having a variable displacement hydraulic device which controls a ratio of an input speed to an output speed of the hydrostatic transmission is disclosed. The transmission assembly further includes a torque reversing mechanical transmission coupled to the hydrostatic transmission and having a first range and a second range. The transmission assembly further includes an output shaft driven by one or more of the hydrostatic transmission and the mechanical transmission which causes a work machine to move at a travel speed and a controller. The controller is operable to determine a transmission load and an equal displacement travel speed ratio based on the transmission load. A shift from the first gear range to the second gear range is based on the equal displacement travel speed ratio. A method of operating a transmission assembly is also disclosed.

Abstract: In the operation of work machines it has been a problem to control the work machine's velocity aspects such as velocity, acceleration, deceleration and jerk because of the plurality of operator interfaces required for such control. The present invention provides an operator interface system for a work machine in which a first pedal is displaceable from a neutral position, and a sensor is operatively coupled with the first pedal and is operable to output a displacement signal corresponding to a location of the first pedal. An electronic controller receives the displacement signal and provides a pre-determined control to a velocity aspect of the work machine in response to the displacement signal.

Abstract: A transmission assembly driven by an engine is disclosed. The transmission assembly includes a hydrostatic transmission having a variable displacement hydraulic pump and a hydraulic motor, a mechanical transmission coupled to the hydrostatic transmission for selecting a first gear range and a second gear range, and a controller for receiving operator inputs and generating a displacement command operable to control a displacement of the variable displacement pump. The controller determines the actual displacement. The controller determines a displacement shift level from the actual displacement. The controller executes a shift from the first gear range to the second gear range when the actual displacement reaches displacement shift level. A method of controlling a transmission assembly is also disclosed.

Abstract: A transmission assembly having a hydrostatic transmission with a variable displacement hydraulic device which controls a motor speed ratio. The transmission assembly further includes a mechanical transmission coupled to the hydrostatic transmission and having a first range and a second range and an output shaft driven at a travel speed ratio. The torque through the hydrostatic transmission reverses when the mechanical transmission shifts from the first range to the second range. A synchronous travel speed ratio is the motor speed ratio which produces the same travel speed ratio in both the first gear range and the second gear range. An equal displacement travel speed ratio is the travel speed ratio at which a displacement of the variable displacement device in the second gear range is the same as the displacement in the first gear range. A travel speed ratio differential is a difference between the synchronous speed ratio and the equal displacement travel speed ratio.

Abstract: A transmission assembly having a hydrostatic transmission with a variable displacement hydraulic device which controls a motor speed ratio. The transmission assembly further includes a mechanical transmission coupled to the hydrostatic transmission and having a first range and a second range and an output shaft driven at a travel speed ratio. The torque through the hydrostatic transmission reverses when the mechanical transmission shifts from the first range to the second range. A synchronous travel speed ratio is the motor speed ratio which produces the same travel speed ratio in both the first gear range and the second gear range. An equal displacement travel speed ratio is the travel speed ratio at which a displacement of the variable displacement device in the second gear range is the same as the displacement in the first gear range. A travel speed ratio differential is a difference between the synchronous speed ratio and the equal displacement travel speed ratio.

Abstract: A control apparatus for a continuously variable transmission is disclosed. The control apparatus includes a transmission speed sensor which generates an actual velocity signal in response measuring speed of an output shaft of the continuously variable transmission. The control apparatus further includes a first input device, or speed pedal, which is positionable in one of an infinite number of positions and generates a desired velocity signal corresponding to the position of the speed pedal. The control apparatus yet further includes a controller operable to receive the desired velocity signal, receive the actual velocity signal, calculate a commanded acceleration ac, and generate a commanded velocity Vc based on the desired velocity signal, a jerk value j, and the commanded acceleration ac. A method of controlling a continuously variable transmission is also disclosed.

Abstract: A control apparatus for a continuously variable transmission is disclosed. The control apparatus includes a transmission speed sensor which generates actual velocity signals in response measuring a speed of an output shaft of the continuously variable transmission. The control apparatus further includes a first input device which is positionable in one of a number of positions and generates a desired velocity signal corresponding to the one of the number of positions. The control apparatus yet further includes a controller operable to receive the desired velocity signals, receive the actual velocity signals, determine when rapid changes in the desired velocity are requested by an operator, and generate a commanded acceleration and a commanded velocity based on a jerk value which exceeds a predetermined jerk limit in response to the rapid changes in the desired velocity. A method of controlling a continuously variable transmission is also disclosed.

Abstract: A system and process for providing different levels of jerk in response to speed pedal displacement in a machine including a speed pedal having a range of displacement, a continuously variable transmission, a mechanism for measuring output speed of the continuously variable transmission, and an electronic controller for generating a jerk command signal that is in a one-to-one correspondence with the displacement of the speed pedal and shaping the jerk command signal into a velocity profile command that is applied to the continuously variable transmission and then comparing the output speed of the continuously variable transmission with the velocity profile command for controlling the continuously variable transmission.

Abstract: A default mode control system for controlling a split torque transmission is disclosed. The default mode control system monitors various inputs to the control to detect an on board electrical, electronic fault or mechanical, hydraulic fault. When a fault is detected, the default mode control will recover from the default and then will limit operation of the split torque transmission based on the fault input.

Abstract: The present invention relates to a method and system for controlling a split torque transmission having a hydrostatic transmission and a mechanical transmission. The control system employs a transmission control and includes a transmission input speed sensor, a transmission output speed sensor, a motor speed sensor, a speed input mechanism, a direction control mechanism, and a range selector mechanism. A microprocessor including a fuzzy controller controls the transmission in response to a input from the speed sensors and the speed input mechanism, the direction control mechanism and the range control mechanism.

Abstract: A dual brake mechanism for a vehicle having a first disc brake assembly associated with a first output drive member and a second disc brake assembly associated with an opposite second output drive member includes a primary brake actuator for generating a force engaging the first disc brake assembly and a plurality of push elements for mechanically transmitting that force as a reaction laterally to the second disc brake assembly and simultaneously engaging both. The primary brake actuator features a single actuation chamber for providing the engagement force when pressurized. This avoids the full duplication of componentry at the opposite sides of the vehicle. The dual brake mechanism can be compactly integrated with a steering differential and a secondary parking brake actuator.

Abstract: Vehicle steering differential have heretofore had a number of assembly, disassembly and serviceability disadvantages or have not been compact enough. The instant differential drive assembly overcomes these deficiencies by including a differential steering mechanism having first and second input gears and a plurality of cooperatively associated planetary gear elements driven thereby, and a mounting structure for rotatably supporting the input gears and the planetary gear elements along a central axis and for modularly positioning the differential steering mechanism in a protected location within the opening of a vehicle case. The mounting structure includes a one-piece carrier body defining a mounting face that is adapted to engage another mounting face of the case.