Method of making a hydrostatic transmission having controlled fluid pressure
US6286309A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2000 |
| Grant date | Sep 11, 2001 |
| Priority date | — |
| Expiry date | May 31, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2562
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Methods of controlling fluid pressure, including using a valve mechanism, are disclosed. In one embodiment, a valve mechanism for use in a hydrostatic transmission including a closed porting system for hydraulic fluid and a sump is provided. The valve mechanism includes a valve body mounted to the hydrostatic transmission whereby the valve body is open to the closed porting system at one end thereof and open to the sump at the other end thereof. The valve body has a first open position whereby hydraulic fluid is pulled into the closed system from the sump when the pressure of the fluid in the closed system is below a first pressure, a second open position whereby hydraulic fluid exists the closed system to the sump when the pressure of the fluid is at a second pressure higher than the first pressure, and a closed position when the pressure of the hydraulic fluid in the closed system is at a third pressure higher than the second pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.