Hydraulic drive system and method of operating a hydraulic drive system
US7739941B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2007 |
| Grant date | Jun 22, 2010 |
| Priority date | — |
| Expiry date | Sep 22, 2027 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B15/2838
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic drive system comprises a hydraulic actuator comprising a piston reciprocable between two cylinder heads for actuating a machine. A flow switching device reverses the direction of hydraulic fluid flow to and from chambers on opposite sides of the piston. The piston stops at the end of each piston stroke when a shuttle valve associated with the piston opens to allow hydraulic fluid to flow between the chambers cancelling the differential pressure that acts on the piston to cause reciprocal movement. A controller is programmed to determine when the piston reaches the end of each stroke based upon at least one of hydraulic pump speed, hydraulic fluid pressure, or elapsed time, with each of these measured during each stroke. The controller then sends an electronic signal to command the flow switching device to reverse the direction of hydraulic fluid flow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.