Transient start-up eliminator for pressure piloted valve
US4265272A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1979 |
| Grant date | May 5, 1981 |
| Priority date | — |
| Expiry date | Oct 1, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86598
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control valve assembly (10) is provided for controlling a hydrostatic transmission including a fluid pump having a variable swashplate, a source of control fluid under pressure, and a servo system responsive to the control fluid for varying the swashplate of the fluid pump. The control valve includes a valve body (12), first (26) and second (28) fluid chambers disposed in the valve body, a first fluid passageway (30) disposed in the valve body for directing pressurized control fluid to the first and second fluid chambers and a valve member (16) located in the valve body for controlling the flow of control fluid to the servo system. The pressurized fluid in the first fluid chamber acts on the valve member to bias the valve member in a first direction and the pressurized fluid in the second chamber acts on the valve member to bias the valve member in the second direction opposite the first direction. A viscosity sensitive restriction (64) is disposed in the first fluid passageway and control fluid is directed therethrough to the first and second fluid chambers. The viscosity sensitive restriction maintains substantially equal pressures in the first and second chambers upon initial …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.