Hydraulic power drive unit

Patent metadata

Field	Value
Publication number	US-11230362-B2
Application number	US-201916376701-A
Country	US
Kind code	B2
Filing date	Apr 5, 2019
Priority date	Apr 6, 2018
Publication date	Jan 25, 2022
Grant date	Jan 25, 2022

Abstract

A hydraulic power drive unit (PDU) for a transmission system includes a hydraulic motor for converting hydraulic pressure into torque and rotation; a hydraulic brake system for applying a braking force to the hydraulic motor to prevent rotation of the hydraulic motor, wherein the hydraulic brake system is biased to apply the braking force to the hydraulic motor to prevent rotation of the hydraulic motor, and configured to remove the braking force in response to a supply of hydraulic fluid; and a hydraulic circuit for supplying a flow of hydraulic fluid to the hydraulic motor to pressurise and thereby operate the hydraulic motor and for supplying hydraulic fluid to the hydraulic brake system to pressurise the hydraulic brake system and thereby remove the braking force; wherein the hydraulic circuit comprises a brake supply line for supplying the hydraulic fluid to the hydraulic brake system.

First claim

The invention claimed is:

1. A hydraulic power drive unit (PDU) for a transmission system, the hydraulic PDU comprising:
a hydraulic motor for converting hydraulic pressure into torque and rotation;
a hydraulic brake system for applying a braking force to the hydraulic motor to prevent rotation of the hydraulic motor, wherein the hydraulic brake system is biased to apply the braking force to the hydraulic motor to prevent rotation of the hydraulic motor, and configured to remove the braking force in response to a supply of hydraulic pressure; and
a hydraulic circuit for supplying a flow of hydraulic fluid to the hydraulic motor to pressurise and thereby operate the hydraulic motor and for supplying hydraulic fluid to the hydraulic brake system to pressurise the hydraulic brake system and thereby remove the braking force;
wherein the hydraulic circuit comprises a brake supply line for supplying the hydraulic fluid to the hydraulic brake system;
wherein the brake supply line comprises a flow restricting device to restrict backflow of the hydraulic fluid in the brake supply line away from the hydraulic brake system;
wherein the hydraulic circuit is configured to enable depressurisation of the hydraulic motor while simultaneously preventing depressurisation of the hydraulic brake system to prevent application of the braking force; and
wherein the hydraulic circuit is configured to depressurise the hydraulic motor upon detection of an event suggestive of a stall event.

2. The hydraulic PDU as claimed in claim 1 , wherein the flow restricting device is a non-return valve that prevents backflow of hydraulic fluid in the brake supply line.

3. The hydraulic PDU as claimed in claim 1 , wherein the hydraulic circuit is configured to enable depressurisation of the hydraulic motor by means of a motor return line through which fluid supplied to the hydraulic motor may flow away from the hydraulic motor.

4. The hydraulic PDU as claimed in claim 1 , wherein the hydraulic motor can rotate freely when the braking force is not applied by the hydraulic brake system.

5. The hydraulic PDU as claimed in claim 1 , wherein the hydraulic motor is a reversible hydraulic motor.

6. The hydraulic PDU as claimed in claim 1 , wherein the brake supply line comprises a brake solenoid valve to control the flow of fluid to the hydraulic brake system and allow for depressurisation of the hydraulic brake system.

7. The hydraulic PDU as claimed in claim 6 , wherein the hydraulic circuit further comprises a return line connected to the brake solenoid valve through which fluid may flow from the hydraulic brake system and the hydraulic brake system thereby depressurised, according to the control of the brake solenoid valve.

8. The hydraulic PDU as claimed in claim 1 , wherein the hydraulic circuit comprises a flow-reversing means for controlling a direction of the supply of hydraulic fluid to the hydraulic motor.

9. The hydraulic PDU as claimed in claim 8 , wherein the flow-reversing means comprises an electrohydraulic servo valve (EHSV).

10. A high-lift actuation system for operation of high-lift devices of an aircraft, the high-lift actuation system comprising:
one or more actuators;
a transmission shaft, wherein the transmission shaft is coupled to the one or more actuators to supply torque and rotation to the one or more actuators; and
a hydraulic PDU as claimed in claim 1 , coupled to the transmission shaft to supply torque and rotation to the transmission shaft.

11. The high-lift actuation system as claimed in claim 10 , further comprising one or more sensors for providing information for determining whether a jam may have occurred in the high-lift actuation system.

12. The high-lift actuation system as claimed in claim 11 , wherein the one or more sensors measure the angular displacement of the transmission shaft or the angular displacement of an output shaft of the hydraulic motor, and wherein angular speed can be determined from the angular displacement.

13. An aircraft comprising:
a fuselage;
a wing extending from the fuselage;
one or more high-lift devices arranged on the wing for altering the amount of lift generated by the wing; and
a high-lift actuation system comprising:
one or more actuators;
a transmission shaft, wherein the transmission shaft is coupled to the one or more actuators to supply torque and rotation to the one or more actuators; and

a hydraulic power drive unit (PDU) coupled to the transmission shaft to supply torque and rotation to the transmission shaft, wherein the transmission shaft extends at least partly along the wing and wherein each of the one or more high lift devices is coupled to at least one of the one or more actuators for actuation of the one or more high lift devices, and the hydraulic PDU is arranged in the fuselage; and
wherein the hydraulic PDU comprises:
a hydraulic motor for converting hydraulic pressure into torque and rotation;
a hydraulic brake system for applying a braking force to the hydraulic motor to prevent rotation of the hydraulic motor, wherein the hydraulic brake system is biased to apply the braking force to the hydraulic motor to prevent rotation of the hydraulic motor, and configured to remove the braking force in response to a supply of hydraulic pressure; and
a hydraulic circuit for supplying a flow of hydraulic fluid to the hydraulic motor to pressurise and thereby operate the hydraulic motor and for supplying hydraulic fluid to the hydraulic brake system to pressurise the hydraulic brake system and thereby remove the braking force;
wherein the hydraulic circuit comprises a brake supply line for supplying the hydraulic fluid to the hydraulic brake system;
wherein the brake supply line comprises a flow restricting device to restrict backflow of the hydraulic fluid in the brake supply line away from the hydraulic brake system; and

wherein the hydraulic circuit is configured to enable depressurisation of the hydraulic motor while simultaneously preventing depressurisation of the hydraulic brake system to prevent application of the braking force.

14. The aircraft as claimed in claim 13 , wherein the high-lift devices comprise slats arranged along a leading edge of the wing, or flaps arranged along a trailing edge of the wing.

15. A method for operating a power drive unit (PDU) comprising:
supplying hydraulic fluid to a hydraulic motor via a hydraulic circuit to pressurise the hydraulic motor which converts hydraulic pressure into torque and rotation; and
supplying hydraulic fluid to a hydraulic brake system via a brake supply line of the hydraulic circuit to pressurise the hydraulic brake system and thereby remove a braking force applied to the hydraulic motor so as to allow for rotation of the hydraulic motor; followed by
depressurising the hydraulic motor whilst restricting backflow of hydraulic fluid in the brake supply line away from the hydraulic brake system such that the hydraulic motor is depressurised whilst depressurisation of the hydraulic brake system is simultaneously prevented thereby preventing application of the braking force;
wherein the step of depressurising the hydraulic motor whilst restricting backflow of hydraulic fluid in the brake supply line is carried out following the detection of an event suggestive of a stall event of the motor.

16. The method as claimed in claim 15 , wherein restricting backflow of hydraulic fluid in the brake supply line comprises preventing backflow of hydraulic fluid in the brake supply line.

17. The method as claimed in claim 15 further comprising the subsequent step of

Assignees

• Goodrich Actuation Systems Ltd

Inventors

• Jones Tony
• Bacon Peter

Classifications

• F15B2211/327

  electrically or electronically · CPC title

• B64C3/38 Primary

  Adjustment of complete wings or parts thereof · CPC title

• F15B15/26

  Locking mechanisms · CPC title

• B64C13/40 Primary

  using fluid pressure · CPC title

• F15B11/08

  with only one servomotor · CPC title