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US5186213A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 10, 1991 |
| Grant date | Feb 16, 1993 |
| Priority date | — |
| Expiry date | Jun 10, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/87209
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An improved hydraulic servo-valve including a spool (10, 10R, 10L) adapted to slidably move in a valve body (1) to change the direction of flow of a working liquid and vary a flow rate of the working liquid, nozzle back-pressure chambers (18, 18R, 18L) to which a pilot pressure is applied for displacing the spool (10, 10R, 10L), and a flapper mechanism comprising nozzles (19, 19R, 19L) and flappers (20, 20R, 20L) is disclosed. Static pressure bearings (14R, 14L, 141R, 141L, 142R, 142L) are formed at opposite ends of the spool (10, 10R, 10L). In addition, the hydraulic servo-valve is formed with passages extend from a pump port (P) to the nozzle back-pressure chambers (18, 18R, 18L) via the static pressure bearings (14R, 14L, 141R, 141L, 142R, 142L).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.