Search

EP-4368500-B1 - SYSTEMS AND METHODS FOR CONTROLLING PROPELLER CONTROL UNIT FLUID PRESSURE

EP4368500B1EP 4368500 B1EP4368500 B1EP 4368500B1EP-4368500-B1

Inventors

  • KRZYWON, JAGODA
  • LACHANCE, BENOIT
  • JARVO, James

Dates

Publication Date
20260506
Application Date
20231108

Claims (15)

  1. A propeller control unit (66) for an aircraft propulsion system (20) including a propeller (48), the propeller control unit (66) comprising: an actuator (84) configured to rotate propeller blades (54) of the propeller (48) to control a pitch of each of the propeller blades (54); a pump (78) configured to direct hydraulic fluid to the actuator (84); a flow regulator (80) in fluid communication with the pump (78), the flow regulator (80) configured to control a hydraulic fluid pressure of the hydraulic fluid downstream of the pump (78); a pressure sensor (88) in fluid communication with the pump (78), the pressure sensor (88) disposed downstream of the pump (78) and upstream of the actuator (84), the pressure sensor (88) configured to measure the hydraulic fluid pressure and generate a hydraulic fluid pressure signal; an auxiliary relief valve (90) and a servo valve (82), the auxiliary relief valve (90) and the servo valve (82) in fluid communication with the pump (78), wherein each of the servo valve (82), the pump (78), the flow regulator (80), and the auxiliary relief valve (90) bound a main hydraulic fluid flow path (110) of the propeller control unit (66), the pressure sensor (88) in fluid communication with the main hydraulic fluid flow path (110), the auxiliary relief valve (90) configured to control the hydraulic fluid pressure in the main hydraulic fluid flow path (110) independent of the flow regulator (80); and a controller (112) in signal communication with the pressure sensor (88), the controller (112) including a processor (114) in communication with a non-transitory memory (116) storing instructions, which instructions when executed by the processor (114), cause the processor (114) to: monitor the hydraulic fluid pressure signal from the pressure sensor (88); and open the auxiliary relief valve (90) when the hydraulic fluid pressure signal exceeds a hydraulic fluid pressure threshold.
  2. The propeller control unit (66) of claim 1, wherein the hydraulic fluid is oil.
  3. The propeller control unit (66) of claim 1 or 2, wherein the instructions, when executed by the processor (114), further cause the processor (114) to: identify an over-pressure condition or an under-pressure condition is present or absent based on a pressure range for the hydraulic fluid pressure signal.
  4. The propeller control unit (66) of claim 3, wherein the instructions, when executed by the processor (114), further cause the processor (114) to: generate a notification based on identification the over-pressure condition or the under-pressure condition is present.
  5. The propeller control unit (66) of any preceding claim, wherein each of the auxiliary relief valve (90) and the flow regulator (80) are configured to direct the hydraulic fluid from the main hydraulic fluid flow path (110) to an inlet of the pump (78).
  6. The propeller control unit (66) of any preceding claim, wherein the instructions, when executed by the processor (114), further cause the processor (114) to: identify a degraded operational condition of the flow regulator (80) based on the hydraulic fluid pressure signal.
  7. The propeller control unit (66) of claim 6, wherein the instructions, when executed by the processor (114), further cause the processor (114) to: identify the degraded operational condition based on identification of an over-pressure condition of the hydraulic fluid pressure signal which occurs for an amount of time exceeding a time threshold.
  8. The propeller control unit (66) of any preceding claim, wherein the flow regulator (80) includes a spring-biased pressure relief valve (92).
  9. A method for controlling hydraulic fluid pressure for a propeller control unit (66) of an aircraft propulsion system (20), the method comprising: directing hydraulic fluid to an actuator (84) of the propeller control unit (66); measuring a hydraulic fluid pressure of the hydraulic fluid directed to the actuator (84); controlling the hydraulic fluid pressure with a flow regulator (80) by selectively directing the hydraulic fluid into a leakage flow path (76) with the flow regulator (80); and monitoring the hydraulic fluid pressure to identify that an over-pressure condition is present or absent for the hydraulic fluid pressure based on a predetermined pressure range for the hydraulic fluid pressure, wherein: the flow regulator (80) includes a spring-biased pressure relief valve (92) and the step of controlling the hydraulic fluid pressure includes selectively directing the hydraulic fluid into the leakage flow path (76) with the spring-biased pressure relief valve (92); and the step of controlling the hydraulic fluid pressure further includes selectively operating an auxiliary relief valve (90) in fluid communication with the leakage flow path (76).
  10. The method of claim 9, wherein the aircraft propulsion system (20) includes a propeller (48) including a plurality of propeller blades (54), the method further comprising: controlling a pitch of each propeller blade of the plurality of propeller blades (54) with the actuator (84).
  11. The method of claim 10, further comprising feathering each propeller blade of the plurality of propeller blades (54) based on the monitored hydraulic fluid pressure.
  12. An aircraft propulsion system (20) comprising: a propeller (48) including a plurality of variable-pitch propeller blades (54); and an oil system (34) including an oil supply assembly (70), an oil return assembly (72), and the propeller control unit (66) of claim 1, the propeller control unit (66) in fluid communication with the oil supply assembly (70) and the oil return assembly (72), wherein: the actuator (84) is configured to control a pitch of each of the variable-pitch propeller blades (54); the pump (78) is a fixed-displacement pump (78) configured to draw oil from the oil supply assembly (70) and direct the oil to the actuator (84); the flow regulator (80) includes a spring-biased pressure relief valve (92) configured to control an oil pressure of the oil downstream of the pump (78) by selectively directing the oil to the oil return assembly (72); and the auxiliary relief valve (90) is remotely actuatable to an open position and a closed position, the auxiliary relief valve (90) in the open position configured to direct the oil to the oil return assembly (72).
  13. The aircraft propulsion system (20) of claim 12, wherein the auxiliary relief valve (90) is configured as a solenoid valve.
  14. The aircraft propulsion system (20) of claim 12 or 13, wherein the instructions when executed by the processor (114), cause the processor (114) to: remotely actuate the auxiliary relief valve (90) based on the oil pressure signal.
  15. The aircraft propulsion system (20) of claim 12, 13 or 14, wherein the instructions when executed by the processor (114), cause the processor (114) to: control the propeller control unit (66) to feather each propeller blade of the plurality of propeller blades (54) based on the oil pressure signal.

Description

TECHNICAL FIELD This disclosure relates generally to propeller control units for aircraft propulsion systems and, more particularly, to systems and methods for controlling hydraulic fluid pressure for propeller control units. BACKGROUND OF THE ART Some propulsion systems for aircraft may include propellers having variable-pitch propeller blades. Various systems and methods are known in the art for controlling propeller blade pitch. For example, propeller blades may be rotated or otherwise operated using hydraulic control systems and methods. While these known hydraulic control systems and methods have various advantages, there is still room in the art for improvement. US 2017/361919 A1 discloses a prior art propeller blade angle control system. SUMMARY According to an aspect of the present disclosure, a propeller control unit for an aircraft propulsion system including a propeller is provided according to claim 1. In any of the aspects or embodiments described above and herein, the instructions, when executed by the processor, may further cause the processor to identify an over-pressure condition is present or absent based on a pressure range for the hydraulic fluid pressure signal. In any of the aspects or embodiments described above and herein, the hydraulic fluid may be oil. In any of the aspects or embodiments described above and herein, the instructions, when executed by the processor, may further cause the processor to generate a notification based on identification the over-pressure condition is present. In any of the aspects or embodiments described above and herein, the instructions, when executed by the processor, may further cause the processor to identify a degraded operational condition of the flow regulator based on the hydraulic fluid pressure signal. In any of the aspects or embodiments described above and herein, the instructions, when executed by the processor, may further cause the processor to identify the degraded operational condition based on identification of an over-pressure condition of the hydraulic fluid pressure signal which occurs for an amount of time exceeding a time threshold. In any of the aspects or embodiments described above and herein, the flow regulator may include a spring-biased pressure relief valve. In any of the aspects or embodiments described above and herein, each of the auxiliary relief valve and the flow regulator may be configured to direct the hydraulic fluid from the main hydraulic fluid flow path to an inlet of the pump. According to another aspect of the present disclosure, a method for controlling hydraulic fluid pressure for a propeller control unit of an aircraft propulsion system is provided according to claim 9. In any of the aspects or embodiments described above and herein, the aircraft propulsion system may include a propeller including a plurality of propeller blades and the method may further include controlling a pitch of each propeller blade of the plurality of propeller blades with the actuator. In any of the aspects or embodiments described above and herein, the method may further include feathering each propeller blade of the plurality of propeller blades based on the monitored hydraulic fluid pressure. According to another aspect of the present disclosure, an aircraft propulsion system is provided according to claim 12. In any of the aspects or embodiments described above and herein, the auxiliary relief valve may be configured as a solenoid valve. In any of the aspects or embodiments described above and herein, the controller may include a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, may cause the processor to control the propeller control unit to feather each propeller blade of the plurality of propeller blades based on the oil pressure signal. In any of the aspects or embodiments described above and herein, the propeller control unit may further include a servo valve in fluid communication between the pump and the actuator. Each of the servo valve, the pump, the flow regulator, and the auxiliary relief valve may bound a main oil flow path of the propeller control unit. The pressure sensor may be in fluid communication with the main oil flow path. The auxiliary relief valve may be configured to control the oil pressure in the main oil flow path independent of the flow regulator. The present disclosure, and all its aspects, embodiments and advantages associated therewith will become more readily apparent in view of the detailed description provided below, including the accompanying drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a schematic, cutaway view of a propulsion system for an aircraft, in accordance with one or more embodiments of the present disclosure.FIG. 2 illustrates a schematic view of an exemplary oil system for the propulsion system of FIG. 1, in accordance with one or more embodiments of the present disclosure.FIG. 3 illustrates