Hydromechanical transmission
US4043227A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1975 |
| Grant date | Aug 23, 1977 |
| Priority date | — |
| Expiry date | Aug 23, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/19037
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydromechanical vehicle transmission system for an engine most efficiently operated at a single speed is disclosed providing an infinitely variable reduction ratio for a given constant input speed requiring minimum operator skill in operation of the vehicle speed control and the engine torque control in both full and part load operation. The transmission consists of a multi-speed hydrostatic mechanical arrangement using a variable displacement hydrostatic pump-motor in conjunction with a fixed displacement hydrostatic pump-motor providing two power paths through the transmission, one hydrostatic and one mechanical. The preferred embodiment discloses four gear ranges although three gear ranges are sufficient to fulfill the objects of the invention. A split torque recycling planetary unit is coupled with the hydrostatic units and two conventional planet trains, the low and reverse range being fully hydrostatic, the intermediate ranges a combination of hydrostatic and mechanical drive, the high range being hydrostatic and mechanical in the lower output speed portion and fully mechanical in the higher output speed area when the hydrostatic path is locked out and engine speed is incre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.