Hydraulic drive unit
US6539712B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 26, 2000 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Dec 26, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/8609
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic drive unit is disclosed which can prevent the occurrence of cavitation at the time of turning OFF of a hydraulic motor without greatly modifying the circuit configuration and the entire system and which, as a result, can improve the deceleration feeling of the hydraulic motor and prevent the occurrence of a low noise. More specifically, a hydraulic drive unit is disclosed which comprises a pair of main circuits (1), (2) each connecting an oil pressure source with a hydraulic motor (M); a counter-balancing valve (3) disposed halfway of the main circuits (1), (2) so as to be capable of being changed over from one position to another, said counter-balancing valve (3) being provided with a pair of discharge passages (10), (11) and a pair of return passages (12a), (12b), both of which are adapted to be opened and closed for the main circuits (1), (2), a pair of first check valves (13), (14) disposed halfway of the discharge passages (10), (11), a pair of orifices (28), (29) disposed halfway of the return passages (12a), (12b); and a pair of branch passages (21), (22) which are connected to the discharge passages (10), (11) on upstream sides of the first check valves (13), (1…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.