Differential pressure control
First Claim
Patent Images
1. A load sensing hydraulic control system for use with a vehicle including a frame, a plurality of traction devices configured to propel the frame on the ground, a plurality of hydraulic actuators, a variable displacement pump including a pump displacement controller receiving a pump control signal, the variable displacement pump being in fluid communication with the plurality of hydraulic actuators through a discharge passage, and a load sense system providing a maximum pressure signal indicative of the maximum pressure needed by the plurality of hydraulic actuators during operation of the vehicle, the load sensing hydraulic control system comprising:
- an orifice receiving the maximum pressure signal, the orifice being in fluid communication with the pump displacement controller,a check valve receiving the maximum pressure signal and bypassing the orifice when the maximum pressure signal is greater than the pump control signal, anda load sense regulator in fluid communication with the pump displacement controller, the load sense regulator maintaining a pressure differential over the orifice below a predetermined level.
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Accused Products
Abstract
A vehicle with a load sensing hydraulic control system is disclosed.
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Citations
21 Claims
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1. A load sensing hydraulic control system for use with a vehicle including a frame, a plurality of traction devices configured to propel the frame on the ground, a plurality of hydraulic actuators, a variable displacement pump including a pump displacement controller receiving a pump control signal, the variable displacement pump being in fluid communication with the plurality of hydraulic actuators through a discharge passage, and a load sense system providing a maximum pressure signal indicative of the maximum pressure needed by the plurality of hydraulic actuators during operation of the vehicle, the load sensing hydraulic control system comprising:
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an orifice receiving the maximum pressure signal, the orifice being in fluid communication with the pump displacement controller, a check valve receiving the maximum pressure signal and bypassing the orifice when the maximum pressure signal is greater than the pump control signal, and a load sense regulator in fluid communication with the pump displacement controller, the load sense regulator maintaining a pressure differential over the orifice below a predetermined level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A load sensing hydraulic control system for use with a vehicle including a frame, a plurality of traction devices configured to propel the frame on the ground, a plurality of hydraulic actuators, a variable displacement pump including a pump displacement controller receiving a pump control signal, the variable displacement pump being in fluid communication with the plurality of hydraulic actuators through a discharge passage, and a load sense system providing a maximum pressure signal indicative of the maximum pressure needed by the plurality of hydraulic actuators during operation of the vehicle, the load sensing hydraulic control system comprising:
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an orifice receiving the maximum pressure signal, the orifice being in fluid communication with the pump displacement controller, and means for maintaining a pressure differential over the orifice below a predetermined level. - View Dependent Claims (13)
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14. A load sensing hydraulic control system for use with a vehicle including a frame, a plurality of traction devices configured to propel the frame on the ground, a plurality of hydraulic actuators, a variable displacement pump including a pump displacement controller receiving a pump control signal, the variable displacement pump being in fluid communication with the plurality of hydraulic actuators through a discharge passage, a load sense system providing a maximum pressure signal indicative of the maximum pressure needed by the plurality of hydraulic actuators during operation of the vehicle, a compensator configured to reduce a pressure level received to a pressure required by an associated hydraulic actuator at least in part based on the maximum pressure signal received at an input to the compensator, the load sensing hydraulic control system comprising:
a load sense regulator providing a pump discharge pressure to the input of the compensator when the maximum pressure signal decreases. - View Dependent Claims (15, 16, 17, 18)
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19. A vehicle including
a frame, a plurality of traction devices configured to propel the frame on the ground, a plurality of hydraulic actuators, a variable displacement pump in fluid communication with the plurality of hydraulic actuators, a load sense system providing a maximum pressure signal indicative of the maximum pressure needed by the plurality of hydraulic actuators during operation of the vehicle, the load sense system including: -
an orifice that receives the maximum pressure signal upstream of the orifice and generates a pump control signal downstream of the orifice, the pump control signal controlling the variable displacement pump, and a load sense regulator that backfills the maximum pressure signal upstream of the orifice when the pump control signal downstream of the orifice exceeds the maximum pressure signal upstream of the orifice by a predetermined differential pressure. - View Dependent Claims (20, 21)
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Specification