Hydraulic valve
US5222521A · kind A · utility
51Cited by
4References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 8, 1992 |
| Grant date | Jun 29, 1993 |
| Priority date | — |
| Expiry date | May 8, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8671
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A high speed high-performance valve member has a spool that is movable within a cylindrical cavity of a valve body or sleeve. The spool and sleeve are both formed of hardened stainless steel, but the bearing surfaces and lands of the spool are provided with a deposition layer of titanium nitride to give the bearing surface a hard smooth finish. The differential hardness between the spool and sleeve prevents galling. Damage due to cavitation is avoided, and the valve has a failure rate reduced by a factor of about twenty.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.