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US 12,181,055 B2Granted
Hydraulic balancing control valve and ride control system incorporatng same
AssigneeHydraForce, Inc.
InventorsTravis Schmidt, James Draffkorn, Barry German
Life of this patent
Estimating the term…
Abstract
A balancing valve includes four ports. While the pressures at a pair of balancing ports of a hydraulic balancing valve are equal, the valve maintains two other ports in a closed position. Upon a pressure differential between the balancing ports, fluid communication can occur between one of the balancing ports and either of the other ports based upon the direction of the pressure differential. A hydraulic ride control system utilizes the balancing valve together with other control valves to provide ride control functionality.
Claims20
A hydraulic balancing valve, comprising:
- a body, the body defining a bore, a charge port, a pump port, a tank port, and a control port, each of the charge port, the pump port, the tank port, and the control port being in fluid communication with the bore;
- a spool, the spool fluidly isolating the control port from the charge port, the pump port, and the tank port, the spool being movably disposed within the bore for directing hydraulic fluid between the charge port and the pump port and between the charge port and the tank port, the spool including a first pressure surface in fluid communication with the charge port and a second pressure surface in fluid communication with the control port, the first and second pressure surfaces facing in opposing relationship to each other, the spool being movable within the bore between:
- a first position in which the charge port and the tank port are in fluid communication with each other and the charge port and the pump port are in fluid isolation from each other,
- a second position in which the charge port, the tank port, and the pump port are in fluid isolation from each other, and
- a third positon in which the charge port and the pump port are in fluid communication with each other and the charge port and the tank port are in fluid isolation from each other;
- and
- a biasing member, the biasing member operatively connected to the body and spool to bias the spool to the second position and configured to permit movement of the spool to the first position upon a first pressure differential between the first pressure surface and the second pressure surface and to permit movement of the spool to the third position upon a second pressure differential between the first pressure surface and the second pressure surface, the second pressure differential being different from the first pressure differential.
4 more elements
A method of operating a hydraulic balancing valve, comprising:
- providing the hydraulic balancing valve, the hydraulic balancing valve including a body, a spool, and a biasing member, the body defining a bore, a charge port, a pump port, a tank port, and a control port, each of the charge port, pump port, tank port, and control port being in fluid communication with the bore, the spool being movably disposed within the bore for directing hydraulic fluid between the charge port and the pump port and between the charge port and the tank port, the spool including a first pressure surface in fluid communication with the charge port and a second pressure surface in fluid communication with the control port, the first and second pressure surfaces facing in opposing relationship to each other, the spool being movable within the bore between a first position in which the charge port and the tank port are in fluid communication with each other and the charge port and the pump port are in fluid isolation from each other, a second position in which the charge port, the tank port, and the pump port are in fluid isolation from each other, and a third positon in which the charge port and the pump port are in fluid communication with each other and the charge port and the tank port are in fluid isolation from each other, and the biasing member being operatively connected to the body and spool to bias the spool to the second position;
- providing a first charge port pressure at the charge port and a first control port pressure at the control port, the first charge port pressure and the first control port pressure being equal and the biasing member maintaining the spool at the second position;
- providing a second charge port pressure at the charge port and a second control port pressure at the control port, the second charge port pressure being greater than the second control port pressure to define a first pressure differential between the charge port and the control port, the first pressure differential moving the spool from the second position to the first position;
- and
- providing a third charge port pressure at the charge port and a third control port pressure at the control port, the third charge port pressure being less than the third control port pressure to define a second pressure differential between the charge port and the control port, the second pressure differential moving the spool from the second position to the third position.
2 more elements
Dependencies are inferred from the claim text.