Hydraulic system for a steering system of a vehicle
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
B62D-005/30
B62D-005/09
B62D-005/06
출원번호
US-0613684
(2017-06-05)
등록번호
US-10144450
(2018-12-04)
발명자
/ 주소
Wen, Gang
Richards, Travis Neale
Roley, Matthew David
McRostie, Nathanael Garnet
Mwasi, Dwanz Mwalimu
출원인 / 주소
Caterpillar Inc.
대리인 / 주소
Tinker, William R.
인용정보
피인용 횟수 :
0인용 특허 :
7
초록▼
A hydraulic system is provided for a steering system of a vehicle. The hydraulic system includes a pump that supplies pressurized fluid during an operation of the steering system. The hydraulic system also includes an accumulator that is in independent and selective communication with each of the pu
A hydraulic system is provided for a steering system of a vehicle. The hydraulic system includes a pump that supplies pressurized fluid during an operation of the steering system. The hydraulic system also includes an accumulator that is in independent and selective communication with each of the pump and the steering system. When the pump is in the operational state to support the operation of the steering system, some of the fluid may be routed into the accumulator and stored in the accumulator for later use. In the event of failure of the pump when the steering system is in operation, the accumulator provides the required amount of fluid to continue operation of the steering system until charge in the accumulator depletes to a value that is no longer sufficient to support operation of the steering system.
대표청구항▼
1. A hydraulic system for a steering system of a vehicle, the hydraulic system comprising: a pump configured to output pressurized fluid via a primary supply line coupled to an output port of the pump;a priority valve disposed downstream of the pump and located in the primary supply line, the priori
1. A hydraulic system for a steering system of a vehicle, the hydraulic system comprising: a pump configured to output pressurized fluid via a primary supply line coupled to an output port of the pump;a priority valve disposed downstream of the pump and located in the primary supply line, the priority valve configured to allow pressurized fluid from the pump to selectively flow to the steering system via a secondary supply line disposed downstream of the priority valve and coupled to the steering system;a first branch line configured to branch-off from the primary supply line, the first branch line having: a spring-loaded pilot-operated pressure reducing valve having a pre-set reducing pressure for opening the pressure reducing valve in accordance with the pre-set reducing pressure; andan accumulator disposed downstream of the pressure reducing valve and fluidly coupled thereto, wherein the first branch line is configured to charge the accumulator with pressurized fluid from the pump when the pump is normally operational and the pressurized fluid from the pump is one of equal to or greater than the pre-set reducing pressure associated with the pressure reducing valve; anda second branch line configured to branch-off from the secondary supply line and fluidly couple with the accumulator, the second branch line configured to communicate pressurized fluid from the accumulator to the steering system via the secondary supply line for facilitating operation of the steering system when the pump is non-operational. 2. The hydraulic system of claim 1, wherein the first branch line includes a first check valve disposed therein and located between the pressure reducing valve and the accumulator, the first check valve configured to prevent a flow of pressurized fluid from the accumulator to the pressure reducing valve. 3. The hydraulic system of claim 2, wherein the first check valve is set to open with a pressure setting lower than the pre-set reducing pressure of the pressure reducing valve to facilitate an unidirectional flow of pressurized fluid from the pump to the accumulator via the pressure reducing valve. 4. The hydraulic system of claim 3 further comprising a third branch line configured to branch-off from a point in the first branch line between the pressure reducing valve and the first check valve, wherein the third branch line includes: a third check valve disposed therein, the third check valve configured to allow an unidirectional flow of pressurized fluid from the pressure reducing valve for regulating a displacement of the pump via a resolver valve that receives a load pressure signal from a pressure differential system located sequentially between the third check valve and the pump. 5. The hydraulic system of claim 3 further comprising a first orifice disposed in the first branch line and located between the first check valve and the accumulator, the first orifice configured to regulate a flow-rate of pressurized fluid from the pressure reducing valve to the accumulator. 6. The hydraulic system of claim 1 further comprising a second check valve disposed in the second branch line and located between the accumulator and the secondary supply line, the second check valve configured to allow fluid to flow from the accumulator to the steering system via the second branch line when the pump is non-operational and a pressure of fluid in the secondary supply line becomes less than a pressure of fluid in the accumulator. 7. The hydraulic system of claim 6 further comprising a bypass line disposed in parallel to the second check valve and fluidly coupled to the second branch line upstream and downstream of the second check valve, the bypass line having a second orifice disposed therein for regulating a flow-rate of fluid being routed from the secondary supply line to the accumulator via the bypass line. 8. The hydraulic system of claim 7, wherein the second orifice is configured to allow: fluid to return from the steering system to the accumulator via the bypass line when the steering system is operational; andfluid to flow from the accumulator to the steering system via the bypass line when the steering system is non-operational. 9. The hydraulic system of claim 8 further comprising: a first sensor associated with the accumulator, the first sensor configured to output a pressure of fluid present in the accumulator; anda second sensor disposed in the second branch line and located at a point between the second check valve and the accumulator, the second sensor configured to output a pressure of fluid upstream of the accumulator. 10. The hydraulic system of claim 9 further comprising a controller disposed in communication with the first and second sensors, the controller configured to: determine from the outputs of the first and second pressure sensors: if the pressure of fluid upstream of the accumulator is below a pre-determined level, andif the pressure of fluid in accumulator has fallen coterminous with a loss of pressure upstream of the accumulator, and if so,provide a warning signal via a display device communicably coupled to the controller, the warning signal being suggestive of halting the vehicle. 11. A vehicle comprising: at least a pair of wheels;a steering system associated with the pair of wheels; anda hydraulic system fluidly coupled with the steering system, the hydraulic system comprising: a pump configured to output pressurized fluid via a primary supply line coupled to an output port of the pump;a priority valve disposed downstream of the pump and located in the primary supply line, the priority valve configured to selectively allow pressurized fluid from the pump to flow to the steering system via a secondary supply line downstream of the priority valve and coupled to the steering system;a first branch line configured to branch-off from the primary supply line, the first branch line having: a spring-loaded pilot-operated pressure reducing valve having a pre-set reducing pressure for opening the pressure reducing valve in accordance with the pre-set reducing pressure; andan accumulator disposed downstream of the pressure reducing valve and fluidly coupled thereto, wherein the first branch line is configured to charge the accumulator with pressurized fluid from the pump when the pump is normally operational and the pressurized fluid from the pump is one of equal to or greater than the pre-set reducing pressure associated with the pressure reducing valve; anda second branch line configured to branch-off from the secondary supply line and fluidly couple with the accumulator, the second branch line configured to communicate pressurized fluid from the accumulator to the steering system via the secondary supply line for facilitating operation of the steering system when the pump is non-operational. 12. The vehicle of claim 11, wherein the first branch line includes a first check valve disposed therein and located between the pressure reducing valve and the accumulator, the first check valve configured to prevent a flow of pressurized fluid from the accumulator to the pressure reducing valve. 13. The vehicle of claim 12, wherein the first check valve is set to open with a pressure setting lower than the pre-set reducing pressure of the pressure reducing valve to facilitate an unidirectional flow of pressurized fluid from the pump to the accumulator via the pressure reducing valve. 14. The vehicle of claim 13, wherein the hydraulic system further comprises a third branch line configured to branch-off from a point in the first branch line between the pressure reducing valve and the first check valve, wherein the third branch line includes: a third check valve disposed therein, the third check valve configured to allow an unidirectional flow of pressurized fluid from the pressure reducing valve for regulating a displacement of the pump via a resolver valve that receives a load pressure signal from a pressure differential system located sequentially between the third check valve and the pump. 15. The vehicle of claim 13, wherein the hydraulic system further comprises a first orifice disposed in the first branch line and located between the first check valve and the accumulator, the first orifice configured to regulate a flow-rate of pressurized fluid from the pressure reducing valve to the accumulator. 16. The vehicle of claim 11, wherein the hydraulic system further comprises a second check valve disposed in the second branch line and located between the accumulator and the secondary supply line, the second check valve configured to allow fluid to flow from the accumulator to the steering system via the second branch line when the pump is non-operational and a pressure of fluid in the secondary supply line becomes less than a pressure of fluid in the accumulator. 17. The vehicle of claim 16, wherein the hydraulic system further comprises a bypass line disposed in parallel to the second check valve and fluidly coupled to the second branch line upstream and downstream of the second check valve, the bypass line having a second orifice disposed therein and configured to regulate a flow-rate of fluid being routed from the secondary supply line to the accumulator via the bypass line. 18. The vehicle of claim 17, wherein the second orifice is configured to allow fluid to return from the steering system to the accumulator when the steering system is operational. 19. The vehicle of claim 18, wherein the hydraulic system further comprises: a first sensor associated with the accumulator, the first sensor configured to output a pressure of fluid present in the accumulator; anda second sensor disposed in the second branch line and located at a point between the second check valve and the accumulator, the second sensor configured to output a pressure of fluid upstream of the accumulator. 20. The vehicle of claim 19, wherein the hydraulic system further comprises a controller disposed in communication with the first and second sensors, the controller configured to: determine from the outputs of the first and second pressure sensors: if the pressure of fluid upstream of the accumulator is below a pre-determined level, andif the pressure of fluid in the accumulator has fallen coterminous with a loss of pressure upstream of the accumulator, and if so,provide a warning signal via a display device communicably coupled to the controller, the warning signal being suggestive of halting the vehicle.
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이 특허에 인용된 특허 (7)
Lech Richard J. (Lockport IL), Auxiliary power steering system.
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