HYDRAULIC BALANCING CONTROL VALVE AND RIDE CONTROL SYSTEM INCORPORATNG SAME
First Claim
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1. 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 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, anda 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.
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Accused Products
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.
1 Citation
24 Claims
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1. A hydraulic balancing valve, comprising:
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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 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A hydraulic ride control system comprising:
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a hydraulic cylinder having a chamber, a rod end, and a base end; a reservoir of hydraulic fluid with a first fluid communication passage between the rod end of the hydraulic cylinder and the reservoir; an accumulator with a second fluid communication passage between the base end of the hydraulic cylinder and the accumulator; a pump with a third fluid communication passage between the pump and the accumulator; a first control valve disposed along the first fluid communication passage to control fluid communication between the rod end of the hydraulic cylinder and the reservoir; a second control valve disposed along the second fluid communication passage to control fluid communication between the base end of the hydraulic cylinder and the accumulator; 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, pump port, tank port, and control port being in fluid communication with the bore; a spool, 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; and the accumulator being in fluid communication with the charge port; the pump being in fluid communication with the pump port; the reservoir being in fluid communication with the tank port; and the base end of the hydraulic cylinder being in fluid communication with the control port. - View Dependent Claims (23)
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24. A method of operating a hydraulic balancing valve, comprising:
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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.
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Specification