Two pump hydraulic system with relief valves having different relief pressures
AssigneeKubota Corporation
InventorsMitsuhiko Obe, Hironobu Kubota
Life of this patent
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Abstract
A hydraulic circuit for a working vehicle comprising a first pump, a second pump, a first actuator, a second actuator, and a selector valve having a plurality of control positions. The selector valve is switchable between a first position for connecting the first pump to the first actuator and the second pump to the second actuator, and a second position for connecting the first pump and the second pump to the second actuator. This circuit includes a first relief valve disposed between the selector valve and the first pump, and a second relief valve disposed between the selector valve and the second pump. The first relief valve is set to a higher relief pressure than the second relief valve.
Claims3
A hydraulic circuit for delivering pressurized fluid to a working vehicle comprising:
- a first pump;
- a second pump;
- a first actuator;
- a second actuator;
- a selector valve being switchable between a first position for connecting said first pump to said first actuator and said second pump to said second actuator, and a second position for connecting said first pump and said second pump to only said second actuator;
- a first relief valve disposed between said selector valve and said first pump, said first relief valve having a first predetermined relief pressure;
- a second relief valve disposed between said selector valve and said second pump, said second relief valve having a second predetermined relief pressure;
- and
- said first predetermined relief pressure of said first relief valve having a higher relief pressure than said second predetermined relief pressure of said second relief valve;
- whereby resonance chattering produced by the opening and closing of said first and second relief valves is avoided.
Dependencies are inferred from the claim text.