Patent · US Expired

Hydraulic drive device for work machine

US7533527B2 · kind B2 · utility

18Cited by
17References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 6, 2005
Grant dateMay 19, 2009
Priority date
Expiry dateNov 30, 2025

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB60W2510/305
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

Abstract

A primary object is to provide a hydraulic drive device for a work machine that is capable of optimum control of pump absorption horsepower according to a change of working condition, thereby reducing fuel consumption, and a secondary object is to provide a hydraulic drive device for a work machine that is based on this primary object and capable of restraining variations in the pump absorption horsepower. When working condition identifying unit (41) determines that, for example, a working condition has changed from working condition (a) to (b), engine control system (40a) changes engine output torque characteristic line from engine output torque characteristic line (ELa) to (ELb), and hydraulic pump control system (40b) changes hydraulic pump absorption torque characteristic line from hydraulic pump absorption torque characteristic line (PLa) to (PLb). At output torque points (Ma), (Mb) at which output of engine (17) reaches a maximum, output torque of engine (17) is matched with absorption torque of hydraulic pump (18).

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