Hydraulic system
AssigneeKawasaki Jukogyo Kabushiki Kaisha
InventorsYukito IMAMURA, Hideki TANAKA
Life of this patent
Estimating the term…
Abstract
A hydraulic system includes: a hydraulic pump that supplies hydraulic oil to a hydraulic actuator at a time of moving the hydraulic actuator, the hydraulic pump being a variable displacement pump; an electric motor that drives the hydraulic pump; a regulator that changes a displacement of the hydraulic pump; and control circuitry that controls the electric motor and the regulator. When a state where a torque of the electric motor exceeds a rated torque has continued for a predetermined period, the control circuitry decreases the displacement of the hydraulic pump and increases a rotation speed of the electric motor under a condition that a delivery flow rate of the hydraulic pump is maintained, such that the torque of the electric motor becomes the rated torque or less.
Claims9
A hydraulic system comprising:
- a hydraulic pump that supplies hydraulic oil to a hydraulic actuator at a time of moving the hydraulic actuator, the hydraulic pump being a variable displacement pump;
- an electric motor that drives the hydraulic pump;
- a regulator that changes a displacement of the hydraulic pump;
- and
- control circuitry that controls the electric motor and the regulator, wherein
- when a state where a torque of the electric motor exceeds a rated torque has continued for a predetermined period, the control circuitry decreases the displacement of the hydraulic pump and increases a rotation speed of the electric motor under a condition that a delivery flow rate of the hydraulic pump is maintained, such that the torque of the electric motor becomes the rated torque or less.
Dependencies are inferred from the claim text.