Hydrostatic mechanical transmission and controls therefor
US4024775A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1975 |
| Grant date | May 24, 1977 |
| Priority date | — |
| Expiry date | Jul 9, 1995 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2037/088
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydrostatic mechanical transmission is disclosed having an infinitely variable split torque, planetary drive unit driving a set of range gears, in part mechanically and the remainder through a hydrostatic path comprising variable displacement hydrostatic devices acting alternately as a pump or motor and controlled through a system of hydraulic valves utilizing the same fluid as the hydrostatic devices. Five forward and two reverse ranges are provided in a relatively small package. Control is effected through a manually operated shift lever providing control signals to both the variable displacement hydrostatic devices and range selector unit, with appropriate control and safety features being provided to assure positive and smooth range changes, to prevent reverse rotation in the hydraulic unit, to sense a zero speed condition in the hydraulic units, and to insure positively synchronizing and matching speed conditions for gear engagement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.