Patent · US Expired

Hydraulic drive system

US5535587A · kind A · utility

14Cited by
6References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 30, 1993
Grant dateJul 16, 1996
Priority date
Expiry dateAug 30, 2013

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE02F9/2296
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A hydraulic drive system of the invention comprises a plurality of flow rate sensors (10A, 10B) for detecting respective flow rates supplied to a plurality of hydraulic actuators (3A, 3B), valve controllers (11A, 11B) for respectively controlling a plurality of flow control valves (40A, 40B) such that the flow rates detected by the plurality of flow rate sensors are coincident with the flow rates instructed by a plurality of control levers (5A, 5B), and a pump tilting controller (12; 12A-12F) for controlling a delivery rate of a hydraulic pump (1) such that the delivery rate of the hydraulic pump is smaller by a predetermined flow rate (.DELTA.Q.sub.ref ; X.sub.ref) than the total of the flow rates instructed by the plurality of control levers. The pump tilting controller controls the delivery rate of the hydraulic pump (1) by using flow rate deviations (.DELTA.Q.sub.1, .DELTA.Q.sub.2) resulted from respectively subtracting the flow rates detected by the flow rate sensors (10A, 10B) from the flow rates instructed by the control levers (5A, 5B).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.