Hydraulic Fluid Circuit With Fixed Minimum Back Pressure
First Claim
1. A hydraulic circuit, comprising:
- an actuation valve configured to actuate a flow of hydraulic fluid to and from a hydraulic consumer, the actuation valve having a first position and a second position in which the flow of the hydraulic fluid to and from the hydraulic consumer is actuated;
a first control valve in fluid communication with the actuation valve through a first pilot line, the first control valve being configured to displace the actuation valve to the first position when actuated; and
a second control valve in fluid communication with the actuation valve through a second pilot line, the second control valve being configured to displace the actuation valve to the second position when actuated, the first pilot line and the second pilot line each having a fixed minimum back pressure sufficient to maintain dissolved air in the hydraulic fluid.
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Accused Products
Abstract
A hydraulic circuit is disclosed. The hydraulic circuit may comprise an actuation valve configured to actuate a flow of hydraulic fluid to and from the hydraulic consumer, a first control valve in fluid communication with the actuation valve through a first pilot line and configured to displace the actuation valve to a first position when actuated, and a second control valve in fluid communication with the actuation valve through a second pilot line and configured to displace the actuation valve to a second position when actuated. The first pilot line and the second line may each have a fixed minimum back pressure sufficient to maintain dissolved air in the hydraulic fluid.
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Citations
20 Claims
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1. A hydraulic circuit, comprising:
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an actuation valve configured to actuate a flow of hydraulic fluid to and from a hydraulic consumer, the actuation valve having a first position and a second position in which the flow of the hydraulic fluid to and from the hydraulic consumer is actuated; a first control valve in fluid communication with the actuation valve through a first pilot line, the first control valve being configured to displace the actuation valve to the first position when actuated; and a second control valve in fluid communication with the actuation valve through a second pilot line, the second control valve being configured to displace the actuation valve to the second position when actuated, the first pilot line and the second pilot line each having a fixed minimum back pressure sufficient to maintain dissolved air in the hydraulic fluid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A machine, comprising
a hydraulic consumer; -
a main spool valve configured to actuate a flow of hydraulic fluid to and from the hydraulic consumer, the main spool valve having a first position and a second position in which the flow of the hydraulic fluid to and from the hydraulic consumer is actuated; a first control valve in fluid communication with the main spool valve via a first pilot line and configured to apply hydraulic fluid pressure on the main spool valve to displace the main spool valve to the first position when actuated; a second control valve in fluid communication with the main spool valve via a second pilot line and configured to apply hydraulic fluid pressure on the main spool valve to displace the main spool valve to the second position when actuated, the first control valve operating in a relieving stage in which the hydraulic fluid is permitted to drain through the first pilot line as the main spool valve is displaced to the second position, the second control valve operating in a relieving stage in which the hydraulic fluid is permitted to drain through the second pilot line as the main spool valve is displaced to the first position, the first pilot line being maintained at a fixed minimum back pressure when the first control valve is in the relieving stage and the second pilot line being maintained at the fixed minimum back pressure when the second control valve is in the relieving stage, the fixed minimum back pressure being a fluid pressure sufficient to maintain dissolved air in the hydraulic fluid. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A method of operating a hydraulic circuit of a machine, the hydraulic circuit including a main spool valve configured to actuate a flow of hydraulic fluid to and from a hydraulic consumer, first and second control valves configured to actuate the main spool valve, and first and second pilot lines respectively fluidly connecting the first and second control valves to the main spool valve, the method comprising:
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actuating the first control valve so that a hydraulic fluid pressure is applied to the main spool valve via the first pilot line; displacing the main spool valve to a first position in response to the hydraulic fluid pressure in the first pilot line; operating the second control valve in a relieving stage as the main spool valve is displaced to the first position, the relieving stage of the second control valve permitting hydraulic fluid to drain through the second pilot line; and maintaining the second pilot line at a fixed minimum back pressure when the second control valve is in the relieving stage, the fixed minimum back pressure being a fluid pressure sufficient to maintain dissolved air in the hydraulic fluid. - View Dependent Claims (20)
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Specification