Hydraulic system for a working machine
AssigneeVolvo Construction Equipment AB
InventorRoland Wiktor
Life of this patent
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Abstract
A hydraulic system for a working machine includes a feeding pump; and a plurality of variable displacement hydraulic machines being connected in parallel to the feeding pump; At least one of the variable displacement hydraulic machines is adapted to drive a ground engagement element of the working machine, and at least one of the variable displacement hydraulic machines is adapted to drive a vibrator for vibrating a ground engagement element of the working machine.
Claims14
A hydraulic system for a working machine, said hydraulic system comprising:
- a feeding pump:
- a plurality of variable displacement hydraulic machines being connected in parallel to said feeding pump;
- a first one of said variable displacement hydraulic machines being adapted to drive a ground engagement element of said working machine, and a second one of said variable displacement hydraulic machines being adapted to drive a vibrator for vibrating the ground engagement element of said working machine;
- a speed sensor adapted to determine a value indicative of a rotational speed of the first one of the variable displacement hydraulic machines;
- a displacement sensor adapted to determine a value of an actual displacement of the first one of said variable displacement hydraulic machines;
- and
- a control unit configured to operate the first one of the variable displacement hydraulic machines in response to outputs of the speed sensor and the displacement sensor to drive the ground engagement element in order to obtain a desired driving condition.
A method for operating a working machine comprising a powertrain which in turn comprises a power source and a hydraulic system, said hydraulic system comprising:
- a feeding pump operably connected to said power source;
- a plurality of variable displacement hydraulic machines being connected in parallel to said feeding pump;
- at least a first one of said variable displacement hydraulic machines being adapted to drive a ground engagement element of said working machine, and
- at least a second one of said variable displacement hydraulic machines being adapted to drive a vibrator for vibrating a ground engagement element of said working machine,
- wherein said hydraulic system comprises a speed sensor adapted to determine a value indicative of a rotational speed of the first one of said variable displacement hydraulic machines and a displacement sensor adapted to determine a value of an actual displacement of the first one of said variable displacement hydraulic machines,
- said method comprising:
- determining a desired driving condition of said working machine,
- receiving inputs from said speed sensor and said displacement sensor, and
- operating at least said power source and each one of said variable displacement hydraulic machines being adapted to drive a ground engagement element in response to said inputs from said speed sensor and said displacement sensor in order to obtain said desired driving condition.
A control unit for operating a working machine comprising a powertrain which in turn comprises a power source and a hydraulic system, said hydraulic system comprising:
- a feeding pump operably connected to said power source;
- a plurality of variable displacement hydraulic machines being connected in parallel to said feeding pump;
- at least a first one of said variable displacement hydraulic machines being adapted to drive a ground engagement element of said working machine, and
- at least a second one of said variable displacement hydraulic machines being adapted to drive a vibrator for vibrating a ground engagement element of said working machine,
- wherein said hydraulic system comprises a speed sensor adapted to determine a value indicative of a rotational speed of the first one of said variable displacement hydraulic machines and a displacement sensor adapted to determine a value of an actual displacement of the first one of said variable displacement hydraulic machines,
- said control unit being adapted to:
- receive information indicative of a desired driving condition of said working machine,
- receiving inputs from said speed, sensor and said displacement sensor, and
- issue a signal to at least said power source and to each one of said variable displacement hydraulic machines being adapted to drive a ground engagement element in response to said inputs from said speed sensor and said displacement sensor so that they are operated in order to obtain said desired driving condition.
Dependencies are inferred from the claim text.