Balanced hydraulic propulsion system
US4769991A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 3, 1987 |
| Grant date | Sep 13, 1988 |
| Priority date | — |
| Expiry date | Nov 3, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/782
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A large industrial earthmoving machine having a hydraulic propulsion system comprising at least two hydraulic motors which are powered from a source of hydraulic fluid to drive a common load. Each motor of the hydraulic propulsion system is provided with two compensating valve assemblies. Each compensating valve assembly is provided with a compensating spool and a shuttle spool to provide accurate control of the hydraulic motors. In each pair of compensating valve assemblies, there is a forward compensating valve assembly and a backward valve assembly respectively controlling forward and backward movement of the hydraulic motor. Between the both forward compensating valve assemblies and the respective hydraulic motors, the compensating valve assemblies are fluidically coupled to one another by a small hydraulic communication line that better equalizes hydraulic fluid flow to the motors and prevents domination of one forward compensating valve assembly over the other. Similarly, the backward compensating valve assemblies are provided with an identical small hydraulic communication line accomplishing the same results.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.