Patent · US Expired

Hydraulic drive system

US4845947A · kind A · utility

7Cited by
5References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 30, 1988
Grant dateJul 11, 1989
Priority date
Expiry dateMar 30, 2008

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF15B2211/75
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A hydraulic drive system for one or more hydraulic motors, comprising a pump (1), a tank (25) for hydraulic fluid, one or more control valve sections (10, 11, 12) each being provided with a shunt passage and each being coupled to a respective hydraulic motor, a first shunt conduit (4) including the shunt passages of said control valve sections (10, 11, 12) connected in series for leading off of the tank (25) the temporarly surplus flow of hydraulic fluid from the pump (1), and a feed conduit (3) for connecting the control valve sections (10, 11, 12) in parallel to the pump (1). A second shunt conduit (5) is connected between the pump (1) and the tank (25) and includes a pressure responsive valve (6) which is arranged to operate in response to pressure in said first shunt conduit (4) downstream of a first non-variable restriction (13), and also in response to pressure in said shunt conduit (5) downstream of a second non-variable restriction ( 14), to establish a direct connection through said second shunt conduit (5) from the pump (1) to the tank (5) in relation to the size of the fluid flow in said first shunt conduit (4).

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