Pump and hydraulic system with low pressure priming and over pressurization avoidance features
US6901911B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2002 |
| Grant date | Jun 7, 2005 |
| Priority date | — |
| Expiry date | Feb 24, 2023 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B49/225
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A hydraulic system, such as a fuel injection system, includes a fixed displacement pump with at least one pump piston. A sleeve surrounds each pump piston and provides the method by which fluid displaced by the pumping stroke of the pump piston is directed either to a high pressure area in the pump or a low pressure area. The sleeves are a portion of an electro-hydraulic controller that includes a mechanical bias to bias the pump to a high output position when a pressure differential between the outlet area and the inlet area is relatively low, such as at cold start up. This aspect facilitates priming of the system. In addition, the controller includes a biasing hydraulic surface in opposition to the mechanical biaser that serves to bias the pump to its low output position when the pressure differential between the outlet area and the inlet area is relatively high. This aspect prevents over pressurization in the event that electric current to the controller is disrupted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.