Patent · US Active

Closed loop drive circuit with external brake assist

US9458842B2 · kind B2 · utility

2Cited by
9References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 9, 2011
Grant dateOct 4, 2016
Priority date
Expiry dateJul 27, 2033

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF15B2211/85
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A hydrostatic drive system for a vehicle (10) comprises an open circuit (100), a closed travel circuit (120), an electronic controller (320), and a main variable displacement hydraulic pump (102) driven by an internal combustion engine (12) equipped with a speed sensor (350). The main variable displacement hydraulic pump may be configured to supply hydraulic fluid to a hydraulic consumer (34, 44, 50) via a hydraulic supply line (106). A pressure relief valve (118) may be connected to a reservoir (300) and may be permanently connected to the hydraulic supply line of the open circuit. The electronic controller may be configured to run a strong braking mode in which the electronic controller at least partially increases the displacement of the main variable displacement hydraulic pump such that hydraulic fluid is discharged via the permanently connected pressure relief valve into the reservoir if the sensed engine speed is higher than a predetermined maximum engine speed.

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