Title:
HYDROSTATIC CIRCUITS WITH VARIABLE CHARGE AND VARIABLE FLUSHING SYSTEMS
Document Type and Number:
WIPO Patent Application WO/2012/173815
Kind Code:
A3
Abstract:
A closed hydrostatic circuit (10) with variable charge and variable flushing systems is disclosed. A variable displacement charge pump (47) is configured to supply charge fluid and pilot control fluid to the hydrostatic circuit. An electronically controlled pressure regulating valve (43) is in communication with an output of the charge pump (47) and is linked to a controller (41). When the hydrostatic control system (10) detects a high hydraulic temperature condition, the electronically controlled pressure regulating valve (43), that is in communication with an output of the charge pump (47) and that is linked to a controller (41), increases the charge pump (47) flow. A bidirectional variable displacement hydrostatic motor (14) is connected in parallel to two input/output lines (16). A flush valve (15) is in communication with the hydrostatic motor (14) and both input/output lines (16). The flush valve (15) and hydrostatic motor (14) are both in communication with the flush orifice and a flush relief valve (22). When the pressure regulating valve (43) causes the charge pump (47) to operate at or near a full capacity, fluid exits the flush valve (15) and passes through both the flush orifice and the flush relief valve (22). In contrast, when the pressure regulating valve (43) causes the charge pump (47) to operate at a lower or near minimum capacity, fluid exits the flush valve (15) and passes through the flush orifice only without passing through the flush relief valve (22).
Inventors:
DEMICK CHRISTOPHER J (US)
DVORAK PAUL (US)
SWICK WILLIAM (US)
GUYARD VINCENT (FR)
ELLIOTT CHRISTOPHER (US)
PRUESS CHRISTOPHER (US)
DVORAK PAUL (US)
SWICK WILLIAM (US)
GUYARD VINCENT (FR)
ELLIOTT CHRISTOPHER (US)
PRUESS CHRISTOPHER (US)
Application Number:
PCT/US2012/040874
Publication Date:
March 28, 2013
Filing Date:
June 05, 2012
Export Citation:
Assignee:
CATERPILLAR INC (US)
DEMICK CHRISTOPHER J (US)
DVORAK PAUL (US)
SWICK WILLIAM (US)
GUYARD VINCENT (FR)
ELLIOTT CHRISTOPHER (US)
PRUESS CHRISTOPHER (US)
DEMICK CHRISTOPHER J (US)
DVORAK PAUL (US)
SWICK WILLIAM (US)
GUYARD VINCENT (FR)
ELLIOTT CHRISTOPHER (US)
PRUESS CHRISTOPHER (US)
International Classes:
F15B21/08; F15B13/043; F15B21/0423; F16K17/06; F16K31/04
Foreign References:
| US6457487B1 | 2002-10-01 | |||
| US5207059A | 1993-05-04 | |||
| US5000001A | 1991-03-19 | |||
| US3866422A | 1975-02-18 |
Attorney, Agent or Firm:
SPILLMAN, M., Daniel et al. (Peoria, IL, US)
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