Hydraulic drive system
US5003776A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1989 |
| Grant date | Apr 2, 1991 |
| Priority date | — |
| Expiry date | Jul 12, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/465
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A hydraulic drive system is equipped with an engine, a plurality of hydraulic pumps adapted to be driven by the engine and including a variable displacement hydraulic pump provided with a displacement varying mechanism, a hydraulic motor connected to the variable displacement pump, a hydraulic actuator for actuating the displacement varying mechanism of the variable displacement hydraulic pump, a working fluid feeding means for feeding the hydraulic actuator with a hydraulic fluid of a pressure according to the degree of control of an accelerator lever which is adapted to instruct a target revolution number of the engine, and a low-pressure circuit for allowing the hydraulic fluid to be discharged therethrough from the hydraulic actuator. The system is provided with a maximum pressure limiting means for guiding the hydraulic fluid of the hydraulic fluid feeding means to the low-pressure circuit depending on the degree of control of the accelerator lever, thereby limiting the maximum pressure of the hydraulic fluid and a means for selectively actuating the maximum pressure limiting means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.