Hydraulic drive device
AssigneeKawasaki Jukogyo Kabushiki Kaisha
InventorsHideyasu Muraoka, Nobuyuki Kinoshita, Yoji Yudate, Yoshihiko Hata, Yuki Kuwabara, Yuichi Miyagi
Life of this patent
Estimating the term…
Abstract
This hydraulic drive device supplies and drains a working fluid to and from a hydraulic cylinder and includes: a plurality of hydraulic pump motors including suction ports and discharge ports; a plurality of electric motors respectively connected to the plurality of hydraulic pump motors; and a directional control valve that is connected to a meter-out passage and connects the hydraulic cylinder to the meter-out passage to drain the working fluid from the hydraulic cylinder to the meter-out passage. The suction ports of the plurality of hydraulic pump motors are connected in parallel with the meter-out passage.
Claims9
A hydraulic drive device that supplies and drains a working fluid to and from a hydraulic cylinder, the hydraulic drive device comprising:
- a plurality of hydraulic pump motors including suction ports and discharge ports;
- a plurality of electric motors respectively connected to the plurality of hydraulic pump motors;
- a directional control valve that is connected to a meter-out passage and connects the hydraulic cylinder to the meter-out passage to drain the working fluid from the hydraulic cylinder to the meter-out passage;
- and
- a plurality of unloader valves that drain, to a tank, at least part of the working fluid discharged from the discharge ports of the plurality of hydraulic pump motors, wherein
- the suction ports of the plurality of hydraulic pump motors are connected in parallel with the meter-out passage, and
- an opening degree of each of the plurality of unloader valves is adjusted.
A hydraulic drive device that supplies and drains a working fluid to and from a plurality of hydraulic actuators including a first hydraulic actuator that is a hydraulic cylinder, the hydraulic drive device comprising:
- a plurality of hydraulic pump motors including suction ports and discharge ports, the discharge ports being respectively connected to the plurality of hydraulic actuators;
- a plurality of electric motors respectively connected to the plurality of hydraulic pump motors;
- a directional control valve that is connected to a meter-out passage and connects the first hydraulic actuator to the meter-out passage to drain the working fluid from the first hydraulic actuator to the meter-out passage;
- and
- a first unloader valve, wherein
- the suction ports of the plurality of hydraulic pump motors are connected in parallel with the meter-out passage,
- the plurality of hydraulic pump motors include a first hydraulic pump motor connected to the first hydraulic actuator, and
- the first unloader valve drains, to a tank, at least part of the working fluid discharged from a discharge port of the first hydraulic pump motor, and an opening degree of the first unloader valve is adjusted.
Dependencies are inferred from the claim text.