Split-pressure dual pump hydraulic fluid supply system for a multi-speed transmission and method
US8128377B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 2007 |
| Grant date | Mar 6, 2012 |
| Priority date | — |
| Expiry date | Sep 29, 2031 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H57/04
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A split-pressure, dual-pump system for supplying hydraulic fluid to a multi-speed transmission is provided. The system includes a low-pressure work circuit operatively connected to a fixed displacement pump, and a high-pressure work circuit operatively connected to a variable displacement pump. The system also includes a regulator valve fluidly coupled to the variable displacement pump via a decrease circuit and an overage circuit for regulating the flow of fluid to the high-pressure work circuit. The invention consists of separating the high-pressure needs of the system into a separate work circuit from the low-pressure needs of the system, and optimizing pump design separately for each work circuit to maximize transmission efficiency and reduce parasitic losses. A method of supplying hydraulic fluid to a multi-speed transmission at variable flow and pressure is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.