Pwm control of actuation pressure for variable-displacement hydraulic pumps

Patent metadata

Field	Value
Publication number	US-2025389260-A1
Application number	US-202418749922-A
Country	US
Kind code	A1
Filing date	Jun 21, 2024
Priority date	Jun 21, 2024
Publication date	Dec 25, 2025
Grant date	—

Abstract

Apparatus and associated methods relate to using a Pulse-Width Modulated (PWM) electro-hydraulic solenoid valve to provide regulation of fluid displacement pumped by a variable-displacement hydraulic pump. The PWM electro-hydraulic solenoid valve regulates fluid conductivity between a hydraulic output port and a hydraulic control port of the variable-displacement hydraulic pump. Such regulation of fluid conductivity therebetween controls fluid displacement through the variable-displacement hydraulic pump. An electronic control unit is configured to generate and transmit a PWM electrical control signal to the PWM electro-hydraulic solenoid valve in response to a metric of the variable-displacement hydraulic pump as measured by a transducer. The electronic control unit generates the PWM electrical control signal so as to control the metric measured to within a predetermined control band about a target value.

First claim

1 . A system for controlling displacement of a hydraulic fluid pumped by a variable-displacement hydraulic pump, the system comprising:
a Pulse-Width Modulated (PWM) electro-hydraulic solenoid valve having first and second hydraulic ports in fluid communication with a hydraulic output port and a hydraulic control port of the variable-displacement hydraulic pump, respectively, thereby regulating fluid conductivity therebetween, wherein such regulation of fluid conductivity between the hydraulic output port and the hydraulic control port controls fluid displacement through the variable-displacement hydraulic pump; a transducer configured to measure a metric of the variable-displacement hydraulic pump; and an electronic control unit in conductive communication with the transducer and the PWM electro-hydraulic solenoid valve, the electronic control unit configured to generate and transmit a PWM electrical control signal to the PWM electro-hydraulic solenoid valve so as to control the metric measured to within a predetermined control band about a target value.

2 . The system of claim 1 , further comprising:
the variable-displacement hydraulic pump having a hydraulic input port and the hydraulic output port, the variable-displacement hydraulic pump configured to pump hydraulic fluid from a hydraulic fluid reservoir in fluid communication with the hydraulic input port to a load in fluid communication with the hydraulic output port; a mechanical control mechanism configured to control displacement of hydraulic fluid pumped from the hydraulic input port to the hydraulic output port of the variable-displacement hydraulic pump; and a hydraulic control piston within a hydraulic control cylinder having a hydraulic chamber in fluid communication with a hydraulic control port, the hydraulic control piston mechanically coupled to the mechanical control mechanism of the variable-displacement hydraulic pump so as to advance a position of the mechanical control mechanism in response to increasing pressure of hydraulic fluid received at the hydraulic control port.

3 . The system of claim 2 , wherein the electronic control unit is further configured to receive the target value from an aircraft.

4 . The system of claim 3 , wherein the predetermined control band is within plus-or-minus 10% of the target value.

5 . The system of claim 2 , wherein the transducer is a pressure sensor configured to measure an output pressure of the hydraulic fluid at the hydraulic output port.

6 . The system of claim 2 , wherein the transducer is a flow sensor configured to measure a volumetric flow of the hydraulic fluid delivered through the output port.

7 . The system of claim 2 , wherein variable-displacement hydraulic pump is a hydraulic control piston pump.

8 . The system of claim 7 , wherein the variable-displacement hydraulic pump is an inline axial hydraulic control piston pump.

9 . The system of claim 8 , wherein the mechanical control mechanism is a swash plate for the inline axial hydraulic control piston pump.

10 . The system of claim 9 , wherein the transducer is an angle sensor configured to measure an angle of a swash plate for an inline axial hydraulic control piston pump.

11 . The system of claim 7 , wherein the variable-displacement hydraulic pump is a bent-axis hydraulic control piston pump.

12 . The system of claim 11 , wherein the mechanical control mechanism is a pivot of the bent-axis hydraulic control piston pump.

13 . The system of claim 12 , wherein the transducer is an angle sensor configured to measure a pivot angle for a bent-axis hydraulic control piston pump.

14 . The system of claim 5 , wherein the PWM electrical control signal generated is conductively communicable with the PWM electro-hydraulic solenoid valve, the PWM electrical control signal having a duty cycle configured to control fluid conductivity of the hydraulic fluid flowing from the output port of the variable-displacement hydraulic pump to the hydraulic control port, thereby controlling the position of the hydraulic control piston.

15 . The system of claim 14 , wherein the PWM electrical control signal generated by the electronic control unit is configured to cause the PWM electro-hydraulic solenoid valve to decrease fluid conductivity of the hydraulic fluid flowing from the hydraulic output port to the hydraulic control port in response to decreasing output pressure at the output port of the variable-displacement hydraulic pump.

16 . The system of claim 14 , wherein the PWM electro-hydraulic solenoid valve is a first PWM electro-hydraulic solenoid valve, the system further comprising:
a second PWM electro-hydraulic solenoid valve having third and fourth hydraulic ports in fluid communication with the hydraulic control port and the hydraulic input port, thereby regulating fluid conductivity therebetween.

17 . The system of claim 16 , wherein the PWM electrical control signal is a first PWM electrical control signal, the electronic control unit is further configured to generate a second PWM electrical control signal, which is communicable with the second PWM electro-hydraulic solenoid valve, the second PWM electrical control signal having a duty cycle configured to control fluid conductivity of the hydraulic fluid flowing from the hydraulic control port to a hydraulic input port.

18 . The system of claim 17 , wherein the second PWM electrical control signal generated by the electronic control unit is configured to cause the second PWM electro-hydraulic solenoid valve to decrease fluid conductivity of the hydraulic fluid flowing from the hydraulic control port to the hydraulic input port in response to increasing output pressure at the output port of the variable-displacement hydraulic pump.

19 . A method for controlling displacement of a hydraulic fluid pumped by a variable-displacement hydraulic pump, the method comprising:
regulating, via a Pulse-Width Modulated (PWM) electro-hydraulic solenoid valve, fluid conductivity between a hydraulic output port and a hydraulic control port of the variable-displacement hydraulic pump, thereby controlling fluid displacement through the variable-displacement hydraulic pump; measuring, via a transducer, a metric of the variable-displacement hydraulic pump; generating, via an electronic control unit, a PWM electrical control signal based on the metric measured; and transmitting the PWM electrical control signal to the PWM electro-hydraulic solenoid valve, thereby controlling the metric measured to within a predetermined control band about a target value.

20 . The method of claim 19 , further comprising:
pumping, via the variable-displacement hydraulic pump, hydraulic fluid from a hydraulic fluid reservoir in fluid communication with a hydraulic input port to a load in fluid communication with a hydraulic output port; controlling, via a mechanical control mechanism, displacement of hydraulic fluid pumped from the hydraulic input port to the hydraulic output port; and positioning, via a hydraulic control piston, the mechanical control mechanism in response to changes in pressure of hydraulic fluid acting on the hydraulic control piston; the hydraulic fluid acting on the hydraulic control piston residing in a hydraulic chamber in fluid communication with a hydraulic control port.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Shook Ryan
• Enke Olaf

Classifications

• F04B49/12

  by varying the length of stroke of the working members · CPC title

• F04B1/26 Primary

  Control · CPC title

• F04B49/06

  Control using electricity (regulating by means of floats actuating electric switches F04B49/04) · CPC title

• F04B49/002

  Hydraulic systems to change the pump delivery · CPC title

• F04B49/065

  and making use of computers · CPC title