Electro-hydraulic actuator system
US5144801A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1989 |
| Grant date | Sep 8, 1992 |
| Priority date | — |
| Expiry date | Apr 28, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B15/18
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An electro-hydraulic actuator having an electric motor disposed in a hydraulic fluid reservoir and connected to drive a hydraulic fluid pump. The actuator includes a piston rod which extends or retracts as a piston is hydraulically driven in a cylinder. An actuator housing forms the reservoir and cylinder and contains hydraulic passages connecting the pump, reservoir and cylinder. The actuator includes a one-way filter for filtering the hydraulic fluid. The hydraulic pump is preferably a rotating piston type and includes a port plate which allows the pump to drive the piston while the retract and extend chambers of the pump have different or unbalanced fluid drive ratios. A load limiting valve protects the system from excessive hydraulic pressure and a position sensor detects the position of the piston rod.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.