Hydraulic actuation system

Abstract

A hydraulic actuation system (10) for an aircraft is provided, the hydraulic actuation system (10) comprising: an actuator (A); a primary actuation arrangement (100) for providing hydraulic fluid to control the actuator (A), wherein the hydraulic actuation system (10) is configured to detect a fault in the actuator (A). The hydraulic actuation system (10) further comprises a secondary actuation arrangement (200) for providing hydraulic fluid to control the actuator (A) in response to detecting a fault in the actuator (A).

Description

Technical Field

[0001] The present disclosure relates to hydraulic actuation systems. In particular, the present disclosure relates to hydraulic systems for propellers, such as pitch change actuators. Background Art

[0002] Hydraulic actuation systems that use hydraulic power to facilitate mechanical motion (e.g., linear, rotary, or oscillatory motion) have many uses in many technologies. Hydraulic actuation systems typically include a hydraulic power source, a metering valve (e.g., an electrohydraulic servo valve) controlled by a controller, and an actuator driven by the hydraulic flow from the metering valve. For example, a typical linear hydraulic actuator includes a piston that can slide within a tube and can be single-acting or double-acting. In a double-acting actuator, hydraulic fluid pressure is applied from a chamber on each side of the piston, and the pressure differential between the two chambers causes the piston to move in one direction or the other.

[0003] Propeller pitch control systems typically use a hydraulic actuation system, known as a pitch change actuator, to control the pitch of the propeller blades. Variable pitch propellers are used on many different types of vehicles, such as aircraft. Typically, the propeller blades are mounted to a rotating hub to allow pivotal movement about their longitudinal axis to permit pitch adjustment. Pitch adjustment is controlled by a hydraulic pitch change actuator.

[0004] In existing pitch change actuation systems, a servo controller, a hydraulic power source, and a metering valve (e.g., an electro-hydraulic servo valve) are located in a static portion of the nacelle, e.g., the static portion of an engine that drives a propeller. In existing systems, when there is a fault (e.g., pressure loss) in the pitch change actuation system, one of two methods can be used to avoid the catastrophic consequences of losing control of the pitch of the propeller blades. One method and system is to provide a pitch lock on the propeller blades to ensure that the blade pitch is locked at a set value slightly less than the pitch of the propeller when oil pressure is lost. Another example of a system and method used in the event of a fault is a counterweight. The counterweight counteracts the aerodynamic forces that attempt to move the blades to a low pitch angle. Both of these examples require bulky and heavy materials on the rotating portion of the nacelle. Summary of the invention

[0005] A hydraulic actuation system for an aircraft is provided, the hydraulic actuation system comprising: an actuator; a primary actuation arrangement for providing hydraulic fluid to control the actuator, wherein the hydraulic actuation system is configured to detect a fault in the actuator. The hydraulic actuation system also includes a secondary actuation arrangement for providing hydraulic fluid to control the actuator in response to detection of a fault in the actuator.

[0006] The actuator may further comprise a first chamber and a second chamber. The primary actuation arrangement may control the hydraulic fluid in the first chamber and the second chamber. The actuator may further comprise a third chamber. The secondary actuation arrangement may control the hydraulic fluid provided in the third chamber.

[0007] The first chamber may be configured to reduce the pitch of a propeller blade of the aircraft.The second chamber may be configured to increase the pitch of the propeller blade of the aircraft.The third chamber may be configured to increase the pitch of the propeller blade of the aircraft.

[0008] The main actuation arrangement may comprise at least one pressure sensor for detecting a fault in the actuator.The main actuation arrangement may further comprise an electric pump, a main pump, a bypass valve and a main electro-hydraulic servo valve for controlling the actuator.

[0009] The auxiliary actuation arrangement may comprise a signal module for providing a signal to the auxiliary electro-hydraulic servo valve to control the actuator.

[0010] The actuator may also include at least one seal.

[0011] The primary actuation arrangement may be provided on a static part of the nacelle and the secondary actuation arrangement may be provided on a rotating part of the nacelle.

[0012] A method is also provided, the method comprising: providing an actuator; providing hydraulic fluid with a primary actuation arrangement to control the actuator; detecting a fault in the actuator through a hydraulic actuation system; and providing hydraulic fluid to the actuator with a secondary actuation arrangement in response to the detected fault in the actuator.

[0013] A nacelle for an aircraft is also provided, the nacelle comprising a rotating part, a static part and a hydraulic actuation system as described above. The primary actuation arrangement is provided in or on the static part, and the secondary actuation arrangement is provided in or on the rotating part. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A hydraulic actuation system is shown.

[0015] Figure 2 Shows Figure 1 Actuator of a hydraulic actuation system. DETAILED DESCRIPTION

[0016] Figure 1The hydraulic actuation system 10 is shown, for example, for use with a pitch change actuator A. Of course, the hydraulic actuation system 10 described herein may be used with other types of actuators and is not limited to use with pitch change actuators.

[0017] Figure 1 The hydraulic actuation system 10 of the present invention may include a main hydraulic actuation arrangement 100 (i.e., a main hydraulic actuation system). The main actuation arrangement 100 may include a maintenance pump 101 (e.g., an electric pump), a main pump 102 (e.g., a mechanical pump), a bypass valve 103, and an electro-hydraulic servo valve 104. The maintenance pump 101, the main pump 102, the bypass valve 103, and the main electro-hydraulic servo valve 104 of the main actuation arrangement 100 may be provided in a static part (in a nacelle (not shown)) of the nacelle. Figure 1 The static part is used to control the rotation of the rotating part (in Figure 1 The main actuation arrangement 100 may also include pressure sensors 105 and 106 in the rotating part of the nacelle. The bypass valve 103 may be connected to the pressure sensor 105 via a transfer bearing 103a. The pressure sensor 105 may be connected to the actuator A via a hydraulic line 103b. The main electro-hydraulic servo valve 104 may be connected to the pressure sensor 106 via a hydraulic line 104a. The pressure sensor 106 may be connected to the actuator A via a hydraulic line 104b.

[0018] The main actuation arrangement 100 is used to provide normal operation to the actuator A to, for example, provide a pitch change to the propeller. That is, the pressure differential provided by the bypass valve 103 and the main electro-hydraulic servo valve 104 works together to change the pitch of the propeller blades in response to a pilot command or a controller of the aircraft. Pressure sensors 105 and 106 monitor the pressure provided in the actuator A and provide input about which hydraulic line needs to be changed to maintain or change the pitch of the propeller blades. The pressure sensors 105 and 106 can provide data to the pilot or controller on the aircraft. The pressure sensors 105 and 106 can detect the default value about the hydraulic system by the controller or the pilot.

[0019] Figure 1 A secondary actuation arrangement 200 (i.e., a secondary hydraulic actuation system) is also shown. The secondary actuation arrangement 200 may include a signal module 201 that provides a signal 201a to a secondary electro-hydraulic servo valve 205. The secondary actuation arrangement 200 may also include a power module 202 for providing power to an electric motor 203, which in turn may be connected to a hydraulic pump 204 that provides hydraulic fluid to the secondary electro-hydraulic servo valve 205. The secondary electro-hydraulic servo valve 205 may be connected to the actuator A via a hydraulic line 205a. Figure 1In the example shown in , the electric motor 203 , the hydraulic pump 204 and the auxiliary electro-hydraulic servo valve 205 may be located in the rotating part of the nacelle.

[0020] The main actuation arrangement 100 provides normal operation to the actuator A. However, when a leak occurs in the actuator A, or there is a pressure loss in the actuator A, the pressure sensors 105 and 106 detect a fault in the main actuation arrangement 100. When a fault (e.g., a pressure loss) is detected in the main actuation arrangement 100, the hydraulic actuation system 1 switches operation to the auxiliary actuator arrangement 200, which may be located on the rotating part of the nacelle. Thus, the auxiliary actuator arrangement 200 acts as a backup system on the nacelle to provide hydraulic function to the actuator A to restore manual or controller operation of the change of the pitch of the propeller blades.

[0021] Figure 2 Shows Figure 1 Actuator A. Actuator A may include a first chamber 300 (also referred to as a fine adjustment chamber) and a second chamber 301 (also referred to as a coarse adjustment chamber). The first chamber 300 and the second chamber 301 act together on actuator A to, for example, provide a pitch change of a propeller blade. The pressure differential between the first chamber 300 and the second chamber 301 allows the pitch angle of the propeller blades to be changed by a pilot or controller of the aircraft. The first chamber 300 or the fine adjustment chamber may be set at a predetermined pressure threshold, such as a predetermined supply pressure (“P 供应 ”). The second chamber 301 or the coarse adjustment chamber can be adjusted from 0 to P 供应 This allows the pitch of the propeller blades to be changed by the pressure difference provided by the first chamber 300 and the second chamber 301. For example, the first chamber 300 can act to reduce the pitch of the propeller blades, while the second chamber 301 can act to increase the pitch of the propeller blades.

[0022] about Figure 1 , the first chamber 300 can be connected to the bypass valve 103 via the transfer bearing 103a and the hydraulic line 103b. The second chamber 301 can be connected to the main electric hydraulic servo valve 104

[0023] Figure 1 The pressure sensors 105 and 106 detect when there is a fault (e.g., a pressure loss) in the first chamber 300 and / or the second chamber 301. When a fault is detected, for example, by the aircraft controller, Figure 1The hydraulic actuation system 10 of the embodiment of the present invention switches from the main actuation arrangement 100 to the auxiliary actuation arrangement 200 to restore the operation of the actuator A to allow the pitch in the propeller blades to be maintained at a safe level. When the main actuation arrangement 100 fails, it may be the case that the external loads on the propeller blades act to reduce the pitch due to the center of gravity and aerodynamic effects of the propeller blades. In order to ensure safe operation, the auxiliary actuation arrangement 200 allows the third chamber 306 to hydraulically control the actuator A and move the propeller blades to a high pitch to counteract the external loads so that the blade pitch is always under control. The pressure provided by the third chamber 306 can be between 0 and P 供应 The third chamber 306 may be connected to the auxiliary electro-hydraulic servo valve 205 provided in the rotating part.

[0024] The actuator A may include at least one of the first dynamic seal 311, the second dynamic seal 312, the third dynamic seal 313, the fourth dynamic seal 314, and the fifth dynamic seal 315 to prevent leakage from the first chamber 300, the second chamber 301, and the third chamber 306. Figure 2 Five seals are shown in FIG. 3 , but it is contemplated that a greater number of seals may be used to prevent leakage. A vent 316 may also be provided between the first dynamic seal 311 and the second dynamic seal 312. Figure 2 In the example shown in , the first seal 311 can prevent external leakage from the third chamber 306 to the exhaust port 316. The second seal 312 prevents external leakage from the first chamber 300 to the exhaust port 316. The third seal 313 prevents leakage from the outside of the third chamber 306. The fourth seal 314 prevents leakage between the first chamber 300 and the second chamber 301. The fifth chamber 315 prevents leakage from the outside of the second chamber 301. The exhaust port 316 also plays a role in preventing leakage from the first chamber 300 and the third chamber 306. The exhaust port 316 also prevents oil from mixing in the actuator A.

[0025] Although the present disclosure has been described with respect to preferred examples, it should be understood that these examples are only illustrative and the claims are not limited to those examples. In view of this disclosure, those skilled in the art will be able to make modifications and alternatives, which are considered to fall within the scope of the appended claims.

Claims

1. A hydraulic actuation system (10) for an aircraft, the hydraulic actuation system (10) comprising: Actuator (A); a main actuation arrangement (100) for providing hydraulic fluid to control the actuator (A), wherein the hydraulic actuation system (10) is configured to detect a fault in the actuator (A); a secondary actuation arrangement (200) for providing hydraulic fluid to control the actuator (A) in response to a detected fault in the actuator (A); wherein the primary actuation arrangement (100) is provided in or on a static part of a nacelle for the aircraft and the secondary actuation arrangement is provided in or on a rotating part of a nacelle for the aircraft, and Therein, the auxiliary actuation arrangement comprises an electric motor, a hydraulic pump and an auxiliary electric hydraulic servo valve.

2. The hydraulic actuation system (10) of claim 1, wherein the actuator (A) further comprises: a first chamber (300) and a second chamber (301), and wherein the main actuation arrangement (100) controls the hydraulic fluid in the first chamber (300) and the second chamber (301); as well as A third chamber (306), wherein the secondary actuation arrangement (100) controls the hydraulic fluid provided in the third chamber (306).

3. The hydraulic actuation system (10) of claim 2, wherein the first chamber (300) is configured to reduce the pitch of a propeller blade of the aircraft; wherein the second chamber (301) is configured to increase the pitch of the propeller blades of the aircraft; and wherein the third chamber (306) is configured to increase the pitch of the propeller blades of the aircraft.

4. The hydraulic actuation system (10) according to any one of claims 1 to 3, wherein the main actuation arrangement (100) comprises at least one pressure sensor (105, 106) for detecting a fault in the actuator (A).

5. The hydraulic actuation system (10) according to any one of claims 1 to 3, wherein the main actuation arrangement (100) comprises an electric pump (101), a main pump (102), a bypass valve (103) and a main electro-hydraulic servo valve (104) for controlling the actuator (A).

6. The hydraulic actuation system (10) according to any one of claims 1 to 3, wherein the auxiliary actuation arrangement (200) comprises a signal module (201) for providing a signal (201a) to an auxiliary electro-hydraulic servo valve (205) to control the actuator (A).

7. The hydraulic actuation system (10) according to any one of claims 1 to 3, wherein the actuator (A) further comprises at least one seal (311, 312, 313, 314, 315).

8. A method for controlling a hydraulic actuation system (10) for an aircraft, the method comprising: providing an actuator (A); A main actuation arrangement (100) is used to provide hydraulic fluid to control the actuator (A); detecting a fault in the actuator (A) by means of the hydraulic actuation system (10); providing hydraulic fluid to the actuator (A) with a secondary actuation arrangement (200) in response to a detected fault in the actuator (A); wherein the primary actuation arrangement (100) is provided in or on a static part of a nacelle for the aircraft and the secondary actuation arrangement is provided in or on a rotating part of a nacelle for the aircraft, and Therein, the auxiliary actuation arrangement comprises an electric motor, a hydraulic pump and an auxiliary electric hydraulic servo valve.

9. The method of claim 8, wherein the actuator (A) further comprises: a first chamber (300) and a second chamber (301), and wherein the main actuation arrangement (100) controls the hydraulic fluid in the first chamber (300) and the second chamber (301); as well as A third chamber (306), wherein the secondary actuation arrangement (100) controls the hydraulic fluid provided in the third chamber (306).

10. The method according to claim 8 or 9, wherein the main actuation arrangement (100) comprises an electric pump (101), a main pump (102), a bypass valve (103) and a main electrohydraulic servo valve (104) for controlling the actuator (A).

11. The method according to claim 8 or 9, wherein the auxiliary actuation arrangement (200) comprises a signal module (201) for providing a signal (201a) to the auxiliary electro-hydraulic servo valve (205) to control the actuator (A).

12. The method according to claim 8 or 9, wherein the actuator (A) further comprises at least one seal (311, 312, 313, 314, 315).

13. A cabin for an aircraft, the cabin comprising: Rotating part; Static part; The hydraulic actuation system according to claim 1; Wherein the primary actuation arrangement (100) is provided in or on the static part and the secondary actuation arrangement is provided in or on the rotating part.

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