Pressurized fluid supply system

• US 6,209,322 B1
• Filed: 04/02/1999
• Issued: 04/03/2001
• Est. Priority Date: 11/13/1996
• Status: Expired due to Fees

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Maruta, Kazuhiro, Endo, Hiroshi, Ishizaki, Naoki, Yoshida, Nobumi
• Primary Examiner(s): Ryznic, John E.
• Application Number:
  US09/269,925
• Time in Patent Office: 732 Days
• Field of Search: 60/384, 60/420, 60/422, 60/426, 60/484, 60/452, 60/445, 60/486
• US Class Current: 60/452
• CPC Class Codes: E02F 9/2235 including an electronic controller
• CPC Class Codes: E02F 9/2285 Pilot-operated systems
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump
• CPC Class Codes: F15B 11/16 with two or more servomotors
• CPC Class Codes: F15B 11/162 for giving priority to particular servomotors or users
• CPC Class Codes: F15B 13/022 Flow-dividers; Priority valves
• CPC Class Codes: F15B 2211/20546 variable capacity
• CPC Class Codes: F15B 2211/214 the pressure sources being hydrotransformers
• CPC Class Codes: F15B 2211/265 Control of multiple pressure sources
• CPC Class Codes: F15B 2211/27 Directional control by means of the pressure source
• CPC Class Codes: F15B 2211/329 actuated by fluid pressure
• CPC Class Codes: F15B 2211/40515 with variable throttles or orifices
• CPC Class Codes: F15B 2211/40569 the pressure compensating valve arranged downstream of the flow control means
• CPC Class Codes: F15B 2211/41509 being connected to a pressure source and a directional control valve
• CPC Class Codes: F15B 2211/41572 being connected to a pressure source and an output member
• CPC Class Codes: F15B 2211/428 actuated by fluid pressure
• CPC Class Codes: F15B 2211/45 Control of bleed-off flow, e.g. control of bypass flow to the return line
• CPC Class Codes: F15B 2211/6054 using shuttle valves
• CPC Class Codes: F15B 2211/6309 the pressure being a pressure source supply pressure
• CPC Class Codes: F15B 2211/6313 : the pressure being a load pressure
• CPC Class Codes: F15B 2211/634 : representing a state of a valve
• CPC Class Codes: F15B 2211/6355 : having valve means
• CPC Class Codes: F15B 2211/71 : Multiple output members, e.g. multiple hydraulic motors or cylinders
• CPC Class Codes: F15B 2211/75 : Control of speed of the output member
• CPC Class Codes: F16H 61/431 : Pump capacity control by electro-hydraulic control means, e.g. using solenoid valves

Abstract

The present invention has an object to enable to supply a discharged pressurized fluid of a hydraulic pump without any energy loss with an arbitrary flow rate distribution ratio to a plurality of actuators. A discharged pressurized fluid of the hydraulic pump 11 is supplied to the first and second actuators 15 and 16 via the first and second variable displacement type hydraulic pump/motors 13 and 14. The first variable displacement type hydraulic pump/motor 13 and the second variable displacement type hydraulic pump/motor 14 are mechanically connected to rotate at the same revolution speed. By this, the pressurized fluid is supplied to the first and second actuators 15 and 16 depending upon displacements of the first and second variable displacement type hydraulic pump/motors.

Claims

1. A pressurized fluid supply system, comprising:

a hydraulic pump;

a plurality of variable displacement type hydraulic pump/motors both connected to a discharge passage of said hydraulic pump, said hydraulic pump/motors being mechanically connected to each other to rotate at the same revolution speed;

a plurality of operating valves connected to said variable displacement type hydraulic pump/motors, respectively;

a plurality of actuators connected to said operating valves, respectively; and

a displacement control means for adjusting a ratio between the displacements of said variable displacement type hydraulic pump/motors at a value in inverse proportion to a pressure ratio between said actuators each connected to the corresponding variable displacement type hydraulic pump/motor.

2. A pressurized fluid supply system, comprising:

a hydraulic pump;

a plurality of variable displacement type hydraulic pump/motors both connected to a discharge passage of said hydraulic pump, said hydraulic pump/motors being mechanically connected to each other to rotate at the same revolution speed;

a plurality of operating valves connected to said variable displacement type hydraulic pump/motors, respectively;

a plurality of actuators connected to said operating valves, respectively;

means for detecting open degrees of said operating valves; and

a displacement control means for adjusting a ratio between the displacements of said variable displacement type hydraulic pump/motors at a value in proportion to a ratio between open degrees of said operating valves each connected to the corresponding variable displacement type hydraulic pump/motors.