Hydraulic actuator for transmissions having reduced noise
US8065930B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 2008 |
| Grant date | Nov 29, 2011 |
| Priority date | — |
| Expiry date | Aug 31, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/20024
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
The present invention provides a three position hydraulic piston assembly for a gear ratio change mechanism for a transmission exhibiting reduced gear shift noise. The three position hydraulic piston assembly includes a master piston and motion retarding assemblies that act near both travel limits of the master piston. The master piston includes symmetrical passageways that provide hydraulic fluid flow to small chambers at each end of the piston that are closed off as the piston approaches its travel limits. Hydraulic fluid trapped in the chambers decelerates the piston and is bled off through an orifice allowing the piston to reach its travel limit and quickly and quietly engage a gear ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.