Hydraulic system, working vehicle and method
AssigneeSandvik Mining and Construction Oy
InventorsSamuli Verho, Harri Vatanen
Life of this patent
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Abstract
A hydraulic system, working vehicle, and method for producing hydraulic power to a hydraulic system of a working vehicle is provided. The hydraulic system includes a fixed displacement hydraulic pump and a speed and torque controlled electric motor for driving the hydraulic pump. An electric controller is arranged to adjust the speed of the electric motor and to thereby adjust produced hydraulic fluid flow and pressure in the system. Further, there is a bypass flow channel including a throttle element for directing limited continuous discharge fluid flow from the system.
Claims9
A hydraulic system of a working vehicle comprising:
- at least one fixed displacement hydraulic pump;
- at least one speed and torque controlled electric motor arranged for driving the hydraulic pump;
- at least one hydraulic actuator;
- at least one electric controller arranged for adjusting a speed of the electric motor thereby adjusting produced hydraulic fluid flow and pressure in the hydraulic system;
- and
- at least one by-pass flow channel including at least one throttle element arranged for directing limited continuous discharge fluid flow from the hydraulic system, wherein the throttle element is a pressure compensated element whereby magnitude of the by-pass flow is configured to be adjusted automatically in response to a magnitude of pressure prevailing in the hydraulic system.
A method of producing hydraulic power to a hydraulic system of a working vehicle, the method comprising:
- rotating a fixed displacement hydraulic pump by means of a speed and torque controlled electric motor;
- controlling rotation of the motor by means of an electric controller arranged for adjusting a speed of the hydraulic pump and thereby adjusting a produced hydraulic fluid flow and pressure in the hydraulic system;
- directing a limited continuous discharge fluid flow via a by-pass flow channel and through a throttle element from an output side of the hydraulic pump to a reservoir, whereby the hydraulic pump is driven continuously, and an output of the hydraulic pump is stabilized;
- and
- restricting a magnitude of the by-pass flow by means of the throttle element for limiting hydraulic energy consumption, wherein the magnitude of the by-pass flow is configured to be adjusted automatically in response to a magnitude of pressure prevailing in the hydraulic system.
Dependencies are inferred from the claim text.