Abstract: A shift mechanism for a transmission having a first and a second combination of gears is disclosed. The shift mechanism has a rod member and a hydraulic actuator operatively connected to an end of the rod member. The hydraulic actuator is configured to move the rod member between a first position at which the first combination of gears is engaged to transmit power, a second position at which the second combination of gears is engaged to transmit power, and a third position at which neither the first nor the second combination of gears is engaged to transmit power. The hydraulic actuator has a first piston slidably connected to the rod member, a second piston fixedly connected to the rod member, and a housing. The housing forms three chambers and has only two fluid conduits in communication with the three chambers.

Abstract: A hydraulic motor system for improved frequency response includes a hydraulic variator having a pump and a motor, wherein the pump includes a variable angle swash plate, and the system further includes an electric actuator for controlling an angle or torque of the swash plate, thereby controlling the motor output characteristics. The electric actuator for controlling the variable angle swash plate may comprise a linear electric motor, ball screw drive or a rotary electric motor. In an example, the rotary electric motor tilts the swash plate by applying a torque to the swash plate at a point away from its tilt axis. In a further example, the rotary electric motor tilts the swash plate via a worm drive or ball screw drive.

Abstract: A method and system for configuring a hydromechanical transmission having a hydraulic pump and a hydraulic motor driven by the hydraulic pump and a pressure-driven actuator employs a particular torque-pressure curve configuration to maximize torque resolution with respect to actuator pressure changes while ensuring that the curve is substantially monotonic in each dimension and at any available motor speed within a predetermined motor speed limit and any available actuator pressure within predetermined actuator pressure limits. The resultant four-dimensional association between actuator pressure, motor speed, primary power source speed and motor torque allows selection of an actuator pressure to provide a desired torque.

Abstract: Apparatus, system, and method for controlling a desired torque output on a hydromechanical transmission. Controlling torque output of a hydromechanical transmission provides improved operator feel and control. A control module determines a desired torque output and determines a pressure necessary to influence the displacement of the variable displacement pump to output the desired torque output. A pressure-controlling valve applies that amount of pressure to an actuator, which moves in response thereto, to change the displacement of the variable displacement pump. When the motor speed changes, the control module adjusts the pressure applied to the actuator to provide the desired torque output.

Abstract: A hydraulic actuator for pump control is disclosed. The hydraulic actuator includes two hydraulically isolated chambers for actuation in one direction and two hydraulically isolated chambers for actuation in an opposite direction. Each of the four chambers is connected to a source of high pressure fluid by an electronically controlled pressure reducing valve.

Abstract: A method of controlling a motor includes monitoring a pressure in a circuit supplying a pressurized fluid to the motor, determining a difference between the monitored circuit pressure and a desired circuit pressure, and determining an actuator command for an actuator that is capable of adjusting a pressure of the pressurized fluid supplied to the motor. The actuator command is determined based on the difference between the monitored circuit pressure and the desired circuit pressure, and is independent of a position of the actuator. The method also includes operating the actuator based on the actuator command.

Abstract: A system and method for variator control employs positively directed electronic make-up and flushing relief valves for more precise torque control of a hydraulic variator, especially during torque reversal, as well as improved cold weather operation. This can improve machine response during periods of severe torque change. The ability to more tightly control variator torque allows more precise torque management algorithms for power control and engine matching purposes. Moreover, the ability to positively control venting of the hydraulic circuit for purposes of fluid cooling allows for more consistent machine response regardless of ambient temperature.

Abstract: A method of operating a machine is disclosed. The machine may have a power system that includes a prime mover, a multiple-ratio transmission, a propulsion device, and power-system controls. The method may include propelling the machine by transmitting power from the prime mover to the propulsion device through the multiple-ratio transmission, while controlling operation of the prime mover and the multiple-ratio transmission with the power-system controls. This may include determining with the power-system controls at least one energy-efficiency estimate based at least in part on energy-efficiency characteristics of the prime mover and energy-efficiency characteristics of the multiple-ratio transmission. Controlling the prime mover and the multiple-ratio transmission may further include controlling a prime-mover operating speed of the prime mover and a transmission drive ratio of the multiple-ratio transmission based at least in part on the at least one energy-efficiency estimate.

Abstract: A hydraulic motor system for improved frequency response includes a hydraulic variator having a pump and a motor, wherein the pump includes a variable angle swash plate, and the system further includes an electric actuator for controlling an angle or torque of the swash plate, thereby controlling the motor output characteristics. The electric actuator for controlling the variable angle swash plate may comprise a linear electric motor, ball screw drive or a rotary electric motor. In an example, the rotary electric motor tilts the swash plate by applying a torque to the swash plate at a point away from its tilt axis. In a further example, the rotary electric motor tilts the swash plate via a worm drive or ball screw drive.

Abstract: A hydromechanical transmission having an input member, a hydrostatic transmission, and a mechanical transmission. The mechanical transmission includes first and second synchronizing assemblies for synchronizing at least one of a first or second output member with a combined output speed from the input member and the hydrostatic transmission. First and second clutch assemblies alternately engage to transfer power from the synchronized output member to a final drive.

Abstract: A hydromechanical transmission having an input member, a hydrostatic transmission, and a mechanical transmission. The mechanical transmission includes first and second synchronizing assemblies for synchronizing at least one of a first or second output member with a combined output speed from the input member and the hydrostatic transmission. First and second clutch assemblies alternately engage to transfer power from the synchronized output member to a final drive.

Abstract: A method of controlling a motor includes monitoring a pressure in a circuit supplying a pressurized fluid to the motor, determining a difference between the monitored circuit pressure and a desired circuit pressure, and determining an actuator command for an actuator that is capable of adjusting a pressure of the pressurized fluid supplied to the motor. The actuator command is determined based on the difference between the monitored circuit pressure and the desired circuit pressure, and is independent of a position of the actuator. The method also includes operating the actuator based on the actuator command.

Abstract: A continuously variable transmission for a machine is disclosed. The machine may have a driven element, a first operator input device, a second operator input device, and a controller. The controller may be configured to receive a first displacement signal associated with the first operator input device, and a second displacement signal associated with the second operator input device. The controller may be further configured to determine a net operator input value as a function of the first and second displacement signals, and regulate an output of the driven element in response to the determined net operator input value.

Abstract: A transmission is provided for a mobile machine. The transmission may have a plurality of available gear combinations selectively engaged to produce multiple stepped output ratios. The transmission may also have a first fluid pump and a second fluid pump. The first fluid pump may be configured to pressurize a first flow of fluid. The second fluid pump may have variable displacement to pressurize a second flow of fluid. At least one of the first and second flows of fluid may be directed to cause selective engagement of the plurality of available gear combinations.

Abstract: A shift mechanism for a transmission having a first and a second combination of gears is disclosed. The shift mechanism has a rod member and a hydraulic actuator operatively connected to an end of the rod member. The hydraulic actuator is configured to move the rod member between a first position at which the first combination of gears is engaged to transmit power, a second position at which the second combination of gears is engaged to transmit power, and a third position at which neither the first nor the second combination of gears is engaged to transmit power. The hydraulic actuator has a first piston slidably connected to the rod member, a second piston fixedly connected to the rod member, and a housing. The housing forms three chambers and has only two fluid conduits in communication with the three chambers.

Abstract: A drivetrain for use in a mobile vehicle is disclosed. The drivetrain may have a combustion engine with a mechanical output, a ground engaging traction device, and a primary transmission unit. The primary transmission unit may be connected to transmit power from the mechanical output to the ground engaging traction device. The drive train may also have a hydraulic power assist unit operatively connected to the mechanical power output to selectively drive the combustion engine.

Abstract: An electric drive system is provided having first and second output members and a driving shaft having an axis or rotation. A plurality of electric motors are arranged adjacent to the driving shaft. Each motor has an output shaft in driving engagement with and substantially parallel to the driving shaft. A differential steering system is operably disposed between the driving shaft and the first and second output members. The differential steering system includes a first planetary gear assembly operably engaged both between the driving shaft and the first output member and between the driving shaft and the second output member. The first planetary gear assembly has an axis of rotation that substantially aligns with the axis of rotation of the driving shaft. A steering motor is operatively engaged with the differential steering system and operable to simultaneously adjust the relative rotational speed of the first and second output members.

Abstract: A method of dissipating power in a propelled machine having a hydromechanical transmission includes converting undesired power to retarding power, and driving an engine with at least a portion of the retarding power prior to substantially dissipating power with any other power-dissipating device.

Abstract: A cooling system for an electric motor includes a cooling duct formed between a cooling jacket and a separate component surface. The separate component surface may define at least a portion of a wall of the cooling duct. The cooling duct may be configured to direct a cooling liquid along at least a portion of the separate component surface and draw heat from the electric motor. An inlet port may be in fluid communication with the cooling duct. The inlet port may be configured to receive the cooling liquid and to introduce the cooling liquid to the cooling duct. An outlet port may be in fluid communication with the cooling duct.

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.