公开(公告)号：US20200248721A1

公开(公告)日：2020-08-06

申请号：US16652134

申请日：2018-09-21

Applicant: KAWASAKI JUKOGYO KABUSHIKI KAISHA

Inventor： Akihiro KONDO ,  Hiroaki MITSUI ,  Toshihisa TOYOTA ,  Haruo YAMADA

IPC: F15B11/02 ,  F15B11/08

Abstract: A hydraulic system includes: a single-rod hydraulic cylinder; a variable displacement pump driven by a rotating machine; a rod-side supply line and a head-side supply line that connect the pump to the hydraulic cylinder; a first tank line that is branched off from the rod-side supply line and connects to a tank; a second tank line that is branched off from the head-side supply line and connects to the tank; and a flow rate adjuster. The flow rate adjuster is configured to: switch a delivery capacity of the pump to a first setting value when a pressure of the head-side supply line is higher than a pressure of the rod-side supply line; and switch the delivery capacity of the pump to a second setting value less than the first setting value when the pressure of the rod-side supply line is higher than the pressure of the head-side supply line.

公开(公告)号：US20220010792A1

公开(公告)日：2022-01-13

申请号：US17295245

申请日：2019-11-15

Applicant: KAWASAKI JUKOGYO KABUSHIKI KAISHA

Inventor： Akihiro KONDO ,  Hiroaki MITSUI ,  Toshihisa TOYOTA ,  Koki MIBU ,  Takashi NAKATSUJI

IPC: F04B49/08 ,  F04B49/06 ,  F15B13/04

Abstract: A hydraulic system includes: a cylinder that moves a moving object in a vertical direction by extension and retraction of a rod; a first bidirectional pump connected to a head-side chamber of the cylinder by a first supply/discharge line; a second bidirectional pump connected to a rod-side chamber of the cylinder by a second supply/discharge line and coupled to the first bidirectional pump in a manner enabling torque to be transmitted between the first and second bidirectional pumps; a relay line connecting the first and second bidirectional pumps such that a hydraulic liquid discharged from one of the first and second bidirectional pumps is introduced into the other of the first and second bidirectional pumps; and a servomotor that drives the first or second bidirectional pump. At least one of the first and second bidirectional pumps is a variable displacement pump whose delivery capacity per rotation is freely variable.

公开(公告)号：US20210048043A1

公开(公告)日：2021-02-18

申请号：US17051147

申请日：2019-04-22

Applicant: KAWASAKI JUKOGYO KABUSHIKI KAISHA

Inventor： Akihiro KONDO ,  Hiroaki MITSUI ,  Toshihisa TOYOTA ,  Takashi NAKATSUJI

IPC: F15B11/08

Abstract: A hydraulic pressure supply device includes: a hydraulic pump capable of changing a discharge capacity; an electric motor capable of changing a rotational frequency; a discharge capacity adjustment mechanism capable of adjusting the discharge capacity of the pump between a maximum and minimum discharge capacity; a pressure detector configured to detect pressure of an operating liquid discharged from the pump; a rotational frequency detector configured to detect the rotational frequency of the motor; and a controller configured to control operations of the motor and adjustment mechanism based on the rotational frequency, detected by the detector, to keep pressure of an actuator at arbitrary pressure, wherein, the controller controls the operation of the adjustment mechanism so the discharge capacity of the pump becomes a set lower limit discharge capacity. The set lower limit discharge capacity is set to be larger than the minimum discharge capacity and be adjustable by the controller.

公开(公告)号：US20240141885A1

公开(公告)日：2024-05-02

申请号：US18381500

申请日：2023-10-18

Applicant: KAWASAKI JUKOGYO KABUSHIKI KAISHA

Inventor： Akihiro KONDO ,  Hiroaki MITSUI

IPC: F04B51/00 ,  F04B49/12

CPC classification number: F04B51/00 ,  F04B49/12

Abstract: A hydraulic pump performance deterioration detection system according to one embodiment includes: a variable displacement hydraulic pump; a switching valve that is connected to the hydraulic pump by a pump line and to a hydraulic actuator by a supply/discharge line; and a regulator that changes a displacement of the hydraulic pump in accordance with a command current and that limits the displacement of the hydraulic pump to a limiting value when a delivery pressure of the hydraulic pump has become higher than a setting value. The performance deterioration detection system further includes: control circuitry that feeds the command current to the regulator; and a pressure sensor that measures the delivery pressure of the hydraulic pump. When the hydraulic actuator is not moving, the control circuitry determines whether or not performance of the hydraulic pump has deteriorated based on a current value of the command current and the delivery pressure of the hydraulic pump measured by the pressure sensor.

公开(公告)号：US20220010817A1

公开(公告)日：2022-01-13

申请号：US17295355

申请日：2019-11-15

Applicant: KAWASAKI JUKOGYO KABUSHIKI KAISHA

Inventor： Akihiro KONDO ,  Hiroaki MITSUI ,  Toshihisa TOYOTA ,  Koki MIBU ,  Takashi NAKATSUJI

IPC: F15B7/00 ,  F04B17/03

Abstract: A hydraulic system includes: a cylinder in which an interior of a tube is divided by a piston into a first pressure chamber and a second pressure chamber; a first bidirectional pump connected to the first pressure chamber by a first supply/discharge line; a second bidirectional pump connected to the second pressure chamber by a second supply/discharge line and coupled to the first bidirectional pump in a manner enabling torque to be transmitted between the first and second bidirectional pumps; a relay line connecting the first and second bidirectional pumps such that a hydraulic liquid discharged from one of the first and second bidirectional pumps is introduced into the other of the first and second bidirectional pumps; and an electric motor that drives the first or second bidirectional pump. At least one of the first and second bidirectional pumps is a variable displacement pump whose delivery capacity per rotation is freely variable.