Hydraulic servo valve with controlled disengagement feature
US5197516A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 1, 1992 |
| Grant date | Mar 30, 1993 |
| Priority date | — |
| Expiry date | May 1, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86614
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic servo valve arangement of the type having a hydraulic amplifier followed by a spool type servo valve second stage, includes a deceleration control mechanism. A spindle-type positioner has first and second positions which respectively permit and block flow of fluid from the first amplifier stage to the first end of the second stage spool. The hydraulic actuator urges the positioner into its first position, and a spring urges the positioner into a second or closed position in the event a failure mode is encountered. A solenoid valve has a communicating port coupled through a dropping orifice to a source of fluid supply and a second port coupled to drain, such that in an actuated condition, input port is at high pressure but in an unactuated condition the input port drops to low pressure. Relief channels and in fluid communication with the one end of the spool member have metered orifices to limit the flow of hydraulic fluid when the spool transits to its null position. Relief passages in communication with the positioner piston have respective transit and null override orifices which achieve smooth movement of the positioner to push the spool member to its set position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.