Methods and systems for a hydromechanical transmission in a vehicle are provided herein. In one example, the transmission system includes a hydrostatic assembly with a hydraulic pump in fluidic communication with a hydraulic motor. The transmission system further includes a controller configured to selectively transition between a torque control mode and a speed control mode of the hydrostatic assembly while the vehicle is on a slope.

Methods and systems for a hydromechanical transmission in a vehicle are provided herein. In one example, the transmission system includes a hydrostatic assembly with a hydraulic pump in fluidic communication with a hydraulic motor. The transmission system further includes a controller configured to selectively transition between a torque control mode and a speed control mode of the hydrostatic assembly while the vehicle is on a slope.

Methods and systems for a hydromechanical transmission are provided herein. In one example, the transmission system includes a hydrostatic assembly and a mechanical assembly coupled in parallel to a first and second planetary gear sets. The transmission system further includes a plurality of clutches designed to shift between two drive ranges in a set of drive ranges that includes a reverse drive range and two forward drive ranges to adjust the input to output speed ratio of the transmission.

A hydrostatic traction drive has a steering function, which is implemented via two laterally acting secondary units (traction motors), which are supplied by a common primary unit (pump) in the open circuit. The primary unit is pressure-controlled. The two secondary units are torque-controlled. The affected vehicle is steerable as a function of a steering command by different torque specifications for the two secondary units. Furthermore, a hydrostatic drive for a mobile work machine has working hydraulics in addition to the traction drive. The working hydraulics are also supplied by the primary unit in parallel to the two secondary units.

A hydrostatic traction drive has a steering function, which is implemented via two laterally acting secondary units (traction motors), which are supplied by a common primary unit (pump) in the open circuit. The primary unit is pressure-controlled. The two secondary units are torque-controlled. The affected vehicle is steerable as a function of a steering command by different torque specifications for the two secondary units. Furthermore, a hydrostatic drive for a mobile work machine has working hydraulics in addition to the traction drive. The working hydraulics are also supplied by the primary unit in parallel to the two secondary units.

Methods and systems for controlling a hydromechanical transmission are proposed. In one example, a control method for a hydrostatic unit of a hydromechanical variable transmission (HVT) is presented, comprising controlling the hydrostatic unit via a feedforward control architecture including a non-linear, multi-coefficient model, wherein the hydrostatic unit comprises a hydrostatic pump and a hydrostatic motor. A desired differential pressure of the hydrostatic unit or a desired hydraulic pump displacement may be used as inputs for the model, where the model's output is a pressure difference for a pump control piston coupled to a swash plate of the hydrostatic unit. Use of the non-linear model permits the hydrostatic unit to be controlled based on load, speed, and/or torque, thereby increasing the adaptability of the control system.

Methods and systems for controlling a hydromechanical transmission are proposed. In one example, a control method for a hydrostatic unit of a hydromechanical variable transmission (HVT) is presented, comprising controlling the hydrostatic unit via a feedforward control architecture including a non-linear, multi-coefficient model, wherein the hydrostatic unit comprises a hydrostatic pump and a hydrostatic motor. A desired differential pressure of the hydrostatic unit or a desired hydraulic pump displacement may be used as inputs for the model, where the model's output is a pressure difference for a pump control piston coupled to a swash plate of the hydrostatic unit. Use of the non-linear model permits the hydrostatic unit to be controlled based on load, speed, and/or torque, thereby increasing the adaptability of the control system.

Methods and systems for a hydromechanical transmission are provided herein. In one example, the transmission system includes a hydrostatic assembly and a mechanical assembly coupled in parallel to a first and second planetary gear sets. The transmission system further includes a plurality of clutches designed to shift between two drive ranges in a set of drive ranges that includes a reverse drive range and two forward drive ranges to adjust the input to output speed ratio of the transmission.

An agricultural vehicle includes a chassis, a header carried by the chassis, an operator cab carried by the chassis, wheels carried by the chassis, at least one wheel driver coupled to at least one of the wheels and configured to drive the at least one coupled wheel at a wheel drive speed, a control handle placed in the operator cab that is displaceable from a zero speed position to a maximum speed position, and a controller operably coupled to the at least one wheel driver. The controller is configured to receive a header type signal indicating a header type of the header and output a resolution signal to the at least one wheel driver to define the maximum speed amount based at least partially on the received header type signal.

A hydrostatic traction drive includes a first hydraulic machine that is coupled to a drive unit. The first hydraulic machine is hydraulically arranged in a hydraulic circuit with a second hydraulic machine. The second hydraulic machine has a drive shaft that is connected in a rotationally fixed fashion to a lockable differential. The traction drive has a control unit that is configured so as to control at least one measure for traction control as a function of a rotational speed of the second hydraulic machine. The at least one measure includes one or more of a measure for detecting a loss of traction and a measure for overcoming the loss of traction. A method for controlling the traction drive includes eliminating a loss of traction of the traction drive with use of the control unit as a function of the rotational speed of the second hydraulic machine.