Power transmission
US4378200A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1980 |
| Grant date | Mar 29, 1983 |
| Priority date | — |
| Expiry date | Sep 4, 2000 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/465
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic system comprising a full flow supercharged variable displacement pump and a fixed displacement charge pump adapted to be driven by the same prime mover as the variable displacement pump for supplying fluid to the variable displacement pump. An orifice is provided in the supply line to the variable displacement pump, a circuit is provided from a point downstream of the orifice to tank pressure, and a feedback valve is provided in series with the circuit. The feedback valve comprises a pair of mutually and oppositely adjustable flow restrictions in series with said circuit. The restrictions are connected to the displacement varying means to vary them equally and oppositely in proportion to the movements of the displacement varying means. A speed sensing control valve is responsive to the pressure level between the two restrictions and the pressure level upstream of the orifice and is connected to the outlet of the variable displacement pump and operable to operate the displacement varying means to reduce the displacement of the pump when the pressure differential between the pressure at the outlet of the feedback means and the pressure upstream of the orifice falls below …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.