Hybrid hydraulic systems for industrial processes
First Claim
1. A control system for a hydraulic drive system including a pump arrangement that supplies a load, the control system comprising:
- a motor coupled to the pump arrangement, the motor configured to cause the pump arrangement to draw first fluid from a reservoir and to direct the first fluid to a supply line that carries the first fluid to the load; and
a first electronic control unit coupled to the pump arrangement, the first electronic control unit being configured to selectively send a control signal to the pump arrangement that causes the pump arrangement to direct part of the first fluid from the supply line to a feeder line, the first electronic control unit also being configured to selectively send another control signal to the pump arrangement that causes the pump arrangement to direct additional fluid from the feeder line to the supply line to join with the first fluid supplied to the load, the first electronic control unit selectively connecting the feeder line to an accumulator configured to receive the part of the first fluid directed to the feeder line and to temporarily store the part of the first fluid.
3 Assignments
0 Petitions
Accused Products
Abstract
A hydraulic drive system for driving a load includes a drive shaft; first and second hydraulic pumps driven by the drive shaft, and a control system that operates the hydraulic drive system in a plurality of modes including: a) a first mode where the second hydraulic pump pumps hydraulic fluid from a supply line to an accumulator; b) a second mode where the second hydraulic pump pumps hydraulic fluid from the accumulator to the supply line; c) a third mode where the second hydraulic pump pumps hydraulic fluid from the supply line to a reservoir; and d) a fourth mode where the second hydraulic pump pumps hydraulic fluid from the reservoir to the supply line. At least the second hydraulic pump is a variable displacement bidirectional pump.
24 Citations
26 Claims
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1. A control system for a hydraulic drive system including a pump arrangement that supplies a load, the control system comprising:
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a motor coupled to the pump arrangement, the motor configured to cause the pump arrangement to draw first fluid from a reservoir and to direct the first fluid to a supply line that carries the first fluid to the load; and a first electronic control unit coupled to the pump arrangement, the first electronic control unit being configured to selectively send a control signal to the pump arrangement that causes the pump arrangement to direct part of the first fluid from the supply line to a feeder line, the first electronic control unit also being configured to selectively send another control signal to the pump arrangement that causes the pump arrangement to direct additional fluid from the feeder line to the supply line to join with the first fluid supplied to the load, the first electronic control unit selectively connecting the feeder line to an accumulator configured to receive the part of the first fluid directed to the feeder line and to temporarily store the part of the first fluid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of operating a hydraulic drive system that includes a pump arrangement and an accumulator, the method comprising:
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using the pump arrangement to drive fluid from a reservoir to a supply line of the hydraulic drive system; determining a load requirement of the hydraulic drive system; determining whether the accumulator is charged; using the pump arrangement to charge the accumulator by directing part of the fluid from the supply line when the load requirement is determined to be below a first threshold and the accumulator is not charged; dumping the part of the fluid to a reservoir when the load requirement is determined to be below the first threshold and the accumulator is charged; providing additional fluid from the accumulator to the supply line when the load requirement is determined to be above a second threshold and the accumulator is charged, the second threshold being above the first threshold; and providing additional fluid from the reservoir to the supply line when the load requirement is determined to be above the first threshold and below the second threshold. - View Dependent Claims (17, 18, 19)
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20. A control system for a hydraulic drive system including a pump arrangement that supplies a load, the control system comprising:
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a motor coupled to the pump arrangement, the motor configured to cause the pump arrangement to draw first fluid from a reservoir and to direct the first fluid to a supply line that carries the first fluid to the load; a first electronic control unit coupled to the pump arrangement, the first electronic control unit being configured to selectively send a control signal to the pump arrangement that causes the pump arrangement to direct part of the first fluid from the supply line to a feeder line, the first electronic control unit also being configured to selectively send another control signal to the pump arrangement that causes the pump arrangement to direct additional fluid from the feeder line to the supply line to join with the first fluid supplied to the load; and a second electronic control unit coupled to the pump arrangement, the second electronic control unit selectively connecting the feeder line to an accumulator configured to receive the part of the first fluid directed to the feeder line and to temporarily store the part of the first fluid. - View Dependent Claims (21, 22, 23, 24)
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25. A control system for a hydraulic drive system including a pump arrangement that supplies a load, the pump arrangement including a first pump and a second pump, the control system comprising:
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a motor coupled to the pump arrangement, the motor configured to cause the pump arrangement to draw first fluid from a reservoir and to direct the first fluid to a supply line that carries the first fluid to the load, the first pump coupling the supply line and the reservoir, the second pump coupling the supply line and the feeder line, the second pump being a variable displacement pump; and a first electronic control unit coupled to the pump arrangement, the first electronic control unit being configured to selectively send a control signal to the pump arrangement that causes the pump arrangement to direct part of the first fluid from the supply line to a feeder line, the first electronic control unit also being configured to selectively send another control signal to the pump arrangement that causes the pump arrangement to direct additional fluid from the feeder line to the supply line to join with the first fluid supplied to the load.
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26. A control system for a hydraulic drive system including a pump arrangement that supplies a load, the pump arrangement including a first pump and a second pump, the control system comprising:
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a motor coupled to the pump arrangement, the motor configured to cause the pump arrangement to draw first fluid from a reservoir and to direct the first fluid to a supply line that carries the first fluid to the load, the first pump coupling the supply line and the reservoir, the second pump coupling the supply line and the feeder line, the second pump being a bi-directional pump; and a first electronic control unit coupled to the pump arrangement, the first electronic control unit being configured to selectively send a control signal to the pump arrangement that causes the pump arrangement to direct part of the first fluid from the supply line to a feeder line, the first electronic control unit also being configured to selectively send another control signal to the pump arrangement that causes the pump arrangement to direct additional fluid from the feeder line to the supply line to join with the first fluid supplied to the load.
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Specification