Hydraulic continuously variable speed transmission with direct clutch valve
US4932208A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1988 |
| Grant date | Jun 12, 1990 |
| Priority date | — |
| Expiry date | Oct 19, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H59/42
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic continuously variable speed transmission comprises a hydraulic closed circuit for hydraulically connecting the hydraulic pump and the hydraulic motor, a direct clutch valve placed in the closed circuit to block it, a speed reduction ratio control actuator to control the speed reduction ratio, a direct clutch actuator for moving said direct clutch valve from a full-open position to a full-closed position, ratio detecting means which detects the speed reduction ratio and valve position detecting means which detects position of the direct clutch valve to find if the direct clutch valve is moved to a slight-open position. The direct clutch valve is moved quickly from the full-open position to the slight-open position when it is found by the ratio detecting means that the speed reduction ratio has become "1", and then the direct clutch valve is moved slowly from the slight-open position to the full-closed position when it is found that the direct clutch valve has been moved to the slight-open position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.