Hydraulic drive system
First Claim
1. An arrangement for controlling a work vehicle, comprising a power source, and a hydraulic circuit comprising a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, and a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream from the actuator via a second conduit wherein the variable displacement hydraulic motor unit is arranged for controlling movement of the actuator, wherein the motor unit is arranged for a rotation connection to the power source in order to transmit energy to the power source.
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Accused Products
Abstract
A hydraulic drive system for an actuator uses a pair of pressure compensated hydraulic machines to control flow to and from the drive chambers of the actuator by varying the controlled pressure of one of the machines. The machines are mechanically coupled to permit energy recovery and charge an accumulator to store supplies energy. The drive system may be combined with other services including a transmission for incorporation in a vehicle. The transmission uses a pressure compensated supply and torque control of the wheels.
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Citations
27 Claims
- 1. An arrangement for controlling a work vehicle, comprising a power source, and a hydraulic circuit comprising a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, and a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream from the actuator via a second conduit wherein the variable displacement hydraulic motor unit is arranged for controlling movement of the actuator, wherein the motor unit is arranged for a rotation connection to the power source in order to transmit energy to the power source.
- 11. An arrangement for controlling a work vehicle, comprising a power source, and a hydraulic circuit comprising a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, and a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream from the actuator via a second conduit wherein the variable displacement hydraulic motor unit is arranged for controlling movement of the actuator, wherein the arrangement comprises a plurality of hydraulic actuators for performing a plurality of work functions, and one variable displacement motor unit is arranged for controlling each work function.
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17. An arrangement for controlling a work vehicle, comprising a power source, and a hydraulic circuit comprising a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, and a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream from the actuator via a second conduit wherein the variable displacement hydraulic motor unit is arranged for controlling movement of the actuator, wherein the pump and the motor unit are coupled in such a way to the power source that they rotate at the same speed.
- 18. A method for controlling a work vehicle, comprising steps of receiving a work function operator signal from an operator of the vehicle, and depending on a requested work function in the operator signal, adjusting a displacement of a variable displacement hydraulic motor unit arranged downstream of a hydraulic actuator, which is arranged for performing the work function, for controlling movements of the actuator, and transmitting energy from the motor unit via a rotation connection to a power source.
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26. A method for controlling a work vehicle, comprising steps of receiving a work function operator signal from an operator of the vehicle, and depending on a requested work function in the operator signal, adjusting a displacement of a variable displacement hydraulic motor unit arranged downstream of a hydraulic actuator, which is arranged for performing the work function, for controlling movements of the actuator, and at a same time as the step of adjusting the displacement of the motor unit is done, supplying a pressurized fluid in a non-throttled manner from a pump to the actuator so that the actuator performs the requested work function, recovering energy by transmitting energy from the motor unit to a power source, and operatively driving the pump by the power source.
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27. A method for controlling a work vehicle, comprising steps of receiving at least one work function operator signal from an operator of the vehicle, and depending on a requested work function in the operator signal, adjusting a displacement of a plurality of variable displacement hydraulic motor units arranged downstream of a plurality of hydraulic actuators arranged for performing a plurality of work functions, for controlling movements of the actuator.
Specification