Hydromechanical transmission
US4131035A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1977 |
| Grant date | Dec 26, 1978 |
| Priority date | — |
| Expiry date | Apr 21, 1997 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2037/0886
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
In a hydromechanical transmission, low and high range clutches are selectively operated in response to variation of an actual speed ratio between an input shaft and an output shaft to complete low or high speed drive power train. The transmission comprises a speed ratio detecting valve for detecting lower and higher limits of a predetermined speed ratio and a clutch control valve for selectively operating the low and high range clutches when the actual speed ratio reaches in a range defined by the lower and higher limits of the predetermined speed ratio. The operation of the clutch control valve is controlled by a pressure control valve in accordance with a difference in value between a first signal responsive to a throttle opening angle and a second signal responsive to the rotation speed of the input shaft such that the low and high range clutches are selectively operated only when the difference between the first and second signals becomes a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.