Gear pump
US4138204A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 7, 1977 |
| Grant date | Feb 6, 1979 |
| Priority date | — |
| Expiry date | Feb 7, 1997 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04C14/26
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A gear pump which comprises a casing provided with an inlet port communicating with an intake chamber, and a delivering port communicating with a delivery chamber. A drive gear is mounted in meshing engagement with a driven gear, each gear being placed in a corresponding bore in the casing, the gears being placed in the flow path between the intake chamber and the delivering chamber. One of the gears contains a central bore with passages which connect the bore to the gaps between adjacent teeth of the gear. A spool is slidable in the central bore for controlling fluid communication through the passages and the movements of the spool are controlled by the pressure difference between the fluid pressure in the delivery chamber and an operating pressure in such a way that the spool is held in a closure position in which the communication through the passages remains blocked as long as the delivery of the pump remains below a given level corresponding to a predetermined pressure difference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.