Synthesized flow-control servovalve
US5240041A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 13, 1992 |
| Grant date | Aug 31, 1993 |
| Priority date | — |
| Expiry date | Mar 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86614
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An improved two-stage servovalve (70) has a pilot-stage and an output-stage. A torque motor (16) produces pivotal movement of a flapper (18) in response to a supplied electrical current. The pilot-stage produces a flow which is used to selectively displace a second-stage spool (61) relative to a body bore. The servovalve has a hydromechanical pressure feedback loop closed about the load and second-stage spool. The pressure feedback loop is intertwined with an electrical spool position feedback loop closed about the spool and driver. The command to the pressure loop is a function of the error of the spool position loop. The gain of the spool position loop dominates that of the pressure loop. The valve has pressure-flow characteristics approximating those of a "flow-control" servovalve but affords access to an electrical signal substantially proportional to the load pressure differential.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.