Rotary servo actuator with internal valve
US5020417A · kind A · utility
Inventor
Key dates
| Filing date | Aug 15, 1990 |
| Grant date | Jun 4, 1991 |
| Priority date | — |
| Expiry date | Aug 15, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/19795
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A fluid-powered servo actuator having a body, an annular piston, and a shaft extending co-axially therewithin. The shaft has an interior chamber located within the body with two fluid channels extending to the chamber in which the piston is mounted. One channel communicates with each side of the piston. A valve spool is positioned in the shaft chamber, and a cam follower or threads are used to longitudinally move the valve spool therewithin in response to its selected rotation. The valve spool has a pair of valve lands which, when in a neutral position, close the two channels. When the valve spool is moved longitudinally, pressurized fluid is communicated with one or the other of the channels to cause the piston to move longitudinally. Splines or rollers convert the longitudinal movement of the piston into rotational movement of the shaft. The cam follower or threads cause the resulting rotational movement of the shaft to move the valve spool back to the neutral position when the shaft has rotated by an amount and in a direction corresponding to the selected amount and direction the valve spool was rotated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.