Control device for a hydrostatic gear
US4756157A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 29, 1986 |
| Grant date | Jul 12, 1988 |
| Priority date | — |
| Expiry date | Oct 29, 2006 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/438
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control circuit for a reversible hydrostatic transmission including a reversible pump having first and second working lines, and a control member having forward and reverse positions to normally direct a working fluid through the first and second working lines respectively. A servo-motor has forward and reverse positions to hold the pump control member in either its forward or reverse positions, and a first subcircuit is provided to conduct a control fluid to the servo motor to hold that motor in either its first or second positions. This first subcircuit includes a pair of piston and cylinder units, with each of these units having a control pressure chamber and a working pressure chamber. A second subcircuit is provided to conduct the working fluid from the working lines to the working pressure chamber of either the first or second piston cylinder unit, and this second subcircuit includes a change over valve to insure that the working pressure is maintained in the appropriate working pressure chamber even if there is a sudden reversal in the load on the pump.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.