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US 10,844,884 B2Granted
Leakage modulation in hydraulic systems containing a three-way spool valve
AssigneeEaton Intelligent Power Limited
InventorMichael Rannow
Life of this patent
Estimating the term…
Abstract
Hydraulic systems and associated methods configured to reduce leakage past a spool valve when the system is in a neutral state. Leakage reduction is achieved by shifting the spool valve within the spool bore. The amount of shifting can be controlled by a pressure controller that sets one or pressures in the system and actively/dynamically adjusts the system to achieve a desired pressure or set of pressures by shifting the spool valve.
Claims22
A hydraulic system having an operational state and a neutral state and comprising:
- a fluid supply line having a supply port and in fluid communication with a work port, the work port being in fluid communication with a tank line having a tank port and being connected to a tank;
- a spool valve having a spool at least partially disposed in a spool bore defining an axis, the spool being axially moveable within the bore and being adapted to regulate fluid flow from the supply line to the work port and from the work port to the tank;
- a driver;
- and
- a pressure controller adapted to receive one or more pressure inputs including at least a sensed pressure at either the supply port or the tank port that is blocked by the spool and provide one or more flow outputs based at least in part on the one or more pressure inputs, the one or more flow outputs causing the driver to axially shift the spool from a neutral position within the bore to an axially shifted neutral position within the bore when the system is in the neutral state.
2 more elements
A three-way spool valve comprising:
- a valve body defining a valve bore that extends along an axis, the valve body also including a supply port, a work port and a tank port all in fluid communication with the valve bore;
- a spool positioned within the bore, the spool including a first land axially separated from a second land by a flow passage, the spool being axially moveable along the axis when the spool valve is in a neutral state, wherein the spool is adapted to be axially shifted by a driver, when the spool valve is in the neutral state, in response to a command from a pressure controller that receives one or more pressure inputs including at least a sensed pressure at either the supply port or the tank port that is blocked by the spool and provides one or more flow outputs based at least in part on the one or more pressure inputs.
Dependencies are inferred from the claim text.