Hydraulic continuously variable speed transmission with direct clutch valve
US4941371A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1988 |
| Grant date | Jul 17, 1990 |
| Priority date | — |
| Expiry date | Oct 19, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2059/363
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic continuously variable speed transmission with a direct clutch valve comprises a hydraulic pump, a hydraulic motor, a hydraulic closed circuit for hydraulically connecting the both, a direct clutch valve placed in the closed circuit, a speed reduction ratio control actuator, and a direct clutch valve controlling device for controlling operations of said direct clutch valve to block the closed circuit when the speed reduction ratio becomes substantially "1". The direct clutch valve controlling device maintains a direct connecting state when an actual engine speed is higher than a direct clutch disconnecting reference engine speed at the speed reduction ratio of approximately "1". Then, the direct clutch valve control device releases the blocking of the closed circuit by the direct valve when a drop of the actual engine speed from the direct clutch disconnecting reference engine speed exceeds a predetermined amount corresponding to the vehicle speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.