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Title:
THRUST REVERSER SYSTEM AND ENGINE ASSEMBLY WITH LOCKOUT MECHANISM
Document Type and Number:
WIPO Patent Application WO/2015/065428
Kind Code:
A1
Abstract:
An engine assembly having a turbine engine, a nacelle surrounding the turbine engine and defining an annular bypass duct between the nacelle and the turbine engine and extending through the turbofan engine to define a generally forward-to-aft bypass airflow path, a thrust reverser having at least one movable control surface, movable to and from a reversing position where at least a portion of the bypass air flow is at least partially reversed, a thrust reverser actuation system having multiple actuators with each actuator having an extendable/retractable portion, a synchronization mechanism to synchronize the multiple actuators, and a lockout mechanism.

Inventors:
WILLETT KENNETH R (US)
Application Number:
PCT/US2013/067758
Publication Date:
May 07, 2015
Filing Date:
October 31, 2013
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
TRIUMPH ACTUATION SYSTEMS YAKIMA LLC (US)
International Classes:
F02K1/76
Domestic Patent References:
WO1994007018A11994-03-31
WO2004099602A22004-11-18
Foreign References:
EP0997630A22000-05-03
GB2154291A1985-09-04
Other References:
None
Attorney, Agent or Firm:
HERRELL, Roger (Dorfman Herrell & Skillman, P.C.,1601 Market Street,Suite 240, Philadelphia PA, US)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. A turbofan engine assembly comprising:

a turbine engine;

a nacelle surrounding the turbine engine and defining an annular bypass duct between the nacelle and the turbine engine and extending through the turbofan engine assembly to define a generally forward-to-aft bypass airflow path;

a thrust reverser having at least one movable control surface, movable to and from a reversing position where at least a portion of the bypass airflow is at least partially reversed;

a thrust reverser actuation system having multiple actuators with each actuator having an extendable/retractable portion operably coupled to the at least one movable control surface to move the at least one movable control surface into and out of the reversing position;

a synchronization mechanism having a worm shaft operably coupled to the extendable/retractable portion of each actuator to synchronize the multiple actuators; and a lockout mechanism selectively coupled to the synchronization mechanism and movable between an inhibit condition, wherein movement of the synchronization mechanism is prevented, and a permit condition, wherein movement of the synchronization mechanism is permitted, wherein the lockout mechanism locks out each of the multiple actuators operably coupled to the synchronization mechanism when the lockout mechanism is in the inhibit condition.

2. The turbofan engine of claim 1 wherein the lockout mechanism comprises a lock shaft movable between a first position, where the synchronization mechanism is enabled and a second position, where the synchronization mechanism is disabled.

3. The turbofan engine of claim 2 wherein when the lock shaft is in the second position a portion of the lock shaft selectively couples with the synchronization mechanism.

4. The turbofan engine of claim 2 wherein the lock shaft comprises a segmented geared portion and a flat face, whereby when the lock shaft is rotated such that the flat face confronts the worm shaft, the lock shaft is in the first position, and when the lock shaft is rotated such that the segmented gear portion confronts the worm shaft, the lock shaft is in the second position.

5. The turbofan engine of claim 4 wherein the extendable/retractable portion further comprises a lead screw.

6. The turbofan engine of claim 5 wherein the worm shaft is operably coupled to the lead screw.

7. The turbofan engine of claim 4 wherein the worm shaft comprises splines at one end and the segmented gear portion engages the splines.

8. The turbofan engine of claim 1 wherein the lockout mechanism further comprises a handle operably coupled to the lockout mechanism.

9. A thrust reverser system, comprising:

a thrust reverser actuation system having multiple actuators with each actuator having a lead screw operably coupled to at least one movable control surface to move the at least one movable control surface into and out of a reversing position;

a synchronization mechanism to synchronize the multiple actuators and comprising a worm shaft operably coupled to the lead screw of each actuator; and

a lockout mechanism having a lock shaft selectively coupled to the worm shaft and movable between an inhibit condition, wherein movement of the worm shaft is prevented, and a permit condition, wherein movement of the worm shaft is permitted.

10. The thrust reverser system of claim 9 wherein the lock shaft comprises a segmented geared portion and a flat face.

1 1. The thrust reverser system of claim 10 wherein the lock shaft is movable between a first position where the flat face faces the worm shaft and a second position where the segmented geared portion selectively couples with a portion of the worm shaft.

12. The thrust reverser system of claim 11 wherein the worm shaft comprises splines at one end and the segmented gear engages the splines to inhibit movement of the worm shaft.

Description:
THRUST REVERSER SYSTEM AND ENGINE ASSEMBLY WITH LOCKOUT

MECHANISM

BACKGROUND OF THE INVENTION

[0001] Contemporary aircraft engines may include a thrust reverser actuation system to assist in reducing the aircraft speed during landing. Typical thrust reversers include a movable element that when in the active position reverses at least a portion of the airflow passing through the engine. During maintenance of such areas of the engine the movement of the movable part is inhibited for safety; currently, this is done manually by a user near the equipment that controls the hydraulic flow to the movable element.

BRIEF DESCRIPTION OF THE INVENTION

[0002] In one aspect, an embodiment of the invention relates to a turbofan engine having a turbine engine, a thrust reverser having at least one movable control surface, a thrust reverser actuation system having multiple actuators with each actuator having an extendable/retractable portion operably coupled to the at least one movable control surface, a synchronization mechanism having a worm shaft operably coupled to the extendable/retractable portion of each actuator to synchronize the multiple actuators and a lockout mechanism selectively coupled to the synchronization mechanism and movable between an inhibit condition, wherein movement of the synchronization mechanism is prevented, and a permit condition, wherein movement of the synchronization mechanism is permitted, wherein the lockout mechanism locks out each of the multiple actuators operably coupled to the synchronization mechanism when the lockout mechanism is in the inhibit condition.

[0003] In another aspect, an embodiment of the invention relates to a thrust reverser system having a thrust reverser actuation system having multiple actuators, a

synchronization mechanism having a worm shaft to synchronize the multiple actuators, and a lockout mechanism having a lock shaft selectively coupled to the worm shaft and movable between an inhibit condition, wherein movement of the worm shaft is prevented, and a permit condition, wherein movement of the worm shaft is permitted.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] In the drawings: [0005] Figure 1 is a schematic view of a turbofan jet engine with a portion of the outer nacelle cut away for clarity;

[0006] Figure 2 is a schematic view of the engine of Figure 1 with an exemplary thrust reverser;

[0007] Figure 3 is a schematic view of a thrust reverser actuation system that may be utilized in the turbofan jet engine of Figure 1;

[0008] Figure 4 is a side view of an actuator that may be utilized in the system of Figure

3;

[0009] Figure 5 is a cross-sectional view of a portion of the actuator of Figure 4;

[0010] Figure 6 is a schematic view of a portion of the actuator and a lockout mechanism, which is in a permit condition;

[0011 ] Figures 7A and 7B illustrate the lockout mechanism in a permit condition and a prohibit condition, respectively; and

[0012] Figure 8 is a schematic view of an alternative orientation of the lockout mechanism.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0013] Figure 1 illustrates a turbofan jet engine assembly 10 having a turbine engine 12, a fan assembly 13, and a nacelle 14. Portions of the nacelle 14 have been cut away for clarity. The nacelle 14 surrounds the turbine engine 12 and defines an annular airflow path or annular bypass duct 16 through the jet engine assembly 10 to define a generally forward-to-aft bypass airflow path as schematically illustrated by the arrow 18.

[0014] A thrust reverser with at least one movable element, which is movable to and from a reversing position, may be used to change the direction of the bypass airflow. In the reversing position, the movable element may be configured to reverse at least a portion of the bypass airflow. There are several methods of obtaining reverse thrust on turbofan jet engine assemblies. Figure 2 schematically illustrates one example of a thrust reverser 20 that may be used in the turbofan jet engine assembly 10. The thrust reverser 20 includes at least one movable control surface or movable element 22. The movable element 22 has been illustrated as a slidable portion of an outer cowling that is capable of axial motion with respect to the forward portion of the nacelle 14. A hydraulic actuator 24 may be coupled to the movable element 22 to move the movable element 22 into and out of the reversing position. In the reversing position, as illustrated, the movable element 22 limits the annular bypass area between the movable element 22 and the turbine engine 12, it also opens up a portion 26 between the movable element 22 and the forward portion of the nacelle 14 such that the air flow path may be reversed as illustrated by the arrows 28. An optional deflector or flap may be included to aid in directing the airflow path between the movable element 22 and the forward portion of the nacelle 14.

[0015] The thrust reverser 20 changes the direction of the thrust force by reversing at least a portion of the bypass airflow. It will be understood that any number of multiple actuators may be utilized to move the movable element into the reversing position.

Figure 3 schematically illustrates a thrust reverser actuation system 50 that may be used in the turbofan jet engine assembly 10 and that includes multiple actuators 52 with each actuator 52 having an extendable/retractable portion 54 that may be operably coupled to the movable element 56 to move the movable element into and out of the reversing position. By way of non-limiting example, the extendable/retractable portion 54 may include a lead screw operably coupled to the movable element 56. The multiple actuators 52 may be fluidly connected with a hydraulic supply line 58 and return line 60.

[0016] A synchronization mechanism 62 may be included to synchronize the multiple actuators 52. The synchronization mechanism 62 may be operably coupled to the multiple actuators in any suitable manner, including that the synchronization mechanism 62 may be operably coupled to the extendable/retractable portion 54 of each actuator 52 as illustrated. The synchronization mechanism may take any suitable form including that the synchronization mechanism 62 may include a worm shaft operably coupled to the extendable/retractable portion 54 of each actuator 52 to synchronize the multiple actuators 52. It will be understood that any number of multiple actuators 52 may be included in the thrust reverser actuation system 50 and that while four actuators 52 have been illustrated, that the thrust reverser actuation system 50 may include as few as two actuators 52.

[0017] A lockout mechanism 64 may be selectively coupled to the synchronization mechanism 62 and may be movable between an inhibit condition, wherein movement of the synchronization mechanism 62 is prevented, and a permit condition, wherein movement of the synchronization mechanism 62 is permitted. The lockout mechanism 64 may lock out each of the multiple actuators 52 operably coupled to the synchronization mechanism 62 when the lockout mechanism 64 is in the inhibit condition.

[0018] Figure 4 illustrates one example of an actuator 52 that may be used in the thrust reverser actuation system 50. The actuator 52 may include a cylinder 72 having an actuator housing 74. An end assembly 76 may be provided to facilitate connection to the movable element and is shown in a retracted position and a partially extended position (in phantom). Figure 5 illustrates a cross section of a portion of the actuator 52. A piston 78 may be axially movable within the cylinder 72 and may be coupled with a lead screw 80. The lead screw 80 and piston 78 may be thought of as forming the extendable/retractable portion of the actuator 52. One end 82 of the lead screw 80 may be held in suitable bearings 84 within the actuator housing 74. As the piston 78 moves back and forth in the cylinder 72, the lead screw 80 rotates at a speed proportional to the velocity of the piston 78. As the piston 78 extends, the end assembly 76 also extends and the movable element of the thrust reverser is moved. The piston 78 is anti-rotated by attachment of the end assembly 76 to the movable element.

[0019] A synchronization mechanism 62 may be operably coupled to the lead screw 80. More specifically, a worm gear shaft 92 has been illustrated as being operably coupled with the lead screw 80 through a worm wheel 94 and may form the synchronization mechanism 62 between multiple actuators 52. Each actuator 52 in the thrust reverser actuation system 50 may include similar components and the worm gear shafts 92 of each actuator 52 may be coupled with each other. Because the speed of the worm gear shaft 92 is also proportional to the velocity of the piston 78, when the worm gear shafts 92 of two or more such actuators 52 are connected together, they will be mechanically

synchronized.

[0020] The synchronization mechanism 62 may be locked into position by a lockout mechanism 64 as illustrated in Figure 6. More specifically, the lockout mechanism 64 may selectively couple with the worm gear shaft 92 and may be movable between a permit condition (Figures 6 and 7A), wherein movement of the synchronization mechanism 62 is permitted, and an inhibit condition (Figure 7B) wherein movement of the synchronization mechanism 62 is prevented. In the illustrated example, the worm gear shaft 92 includes splines 98 on one end of the worm gear shaft 92. The splines 98 may include ridges or teeth on the worm gear shaft 92 that may mesh with portions of the lockout mechanism 64. It will be understood that the splines 98 may be operably coupled with the end worm gear shaft 92 or that the splines 98 may be formed as a portion on the end of the worm gear shaft 92.

[0021] The lockout mechanism has been illustrated as including a lock shaft 102 having a segmented geared portion 104 and a flat face 106. The segmented geared portion 104 may be any suitable portion capable of engaging with the splines 98. In the illustrated example, the segmented geared portion 104 may be concentric cuts in the lock shaft 102 such that the segmented geared portion 104 appears to be equally spaced rings with a profile shaped to mate with the splines 98. The flat face 106 may be formed on one side or angular position of the lock shaft 102 and may extend across all of the rings forming the segmented geared portion 104.

[0022] The lock shaft 102 may be restrained from translating by any suitable bearing(s) 108. The bearing(s) 108 may be installed to prevent linear motion of the lock shaft 102 in both directions. In this manner, the bearing(s) 108 may react the loads applied by the splines 98 when in the inhibit condition.

[0023] A handle 1 10 or other similar mechanism may be operably coupled with the lock shaft 102 and may rotate the lock shaft 102 about its axis to move the lock shaft 102 between a first position and a second position. The handle 1 10 may be formed in any suitable manner and may be operably coupled with the lock shaft 102 in any suitable manner.

[0024] In the illustrated example, the lock shaft 102 may be rotationally movable, by the handle 1 10, between a first position, corresponding to the permit condition of the synchronization mechanism 62 where the synchronization mechanism 62 is enabled and a second position, corresponding to the inhibit condition of the synchronization mechanism 62 where the synchronization mechanism 62 is disabled. More specifically, when the lock shaft 102 is rotated such that the flat face 106 confronts the worm gear shaft 92, the lock shaft 102 is in the first position, and when the lock shaft 102 is rotated such that the segmented geared portion 104 confronts the worm gear shaft 92, the lock shaft 102 is in the second position. In this manner, when the lock shaft 102 is in the second position corresponding to the inhibit condition, a portion of the lock shaft 102 selectively couples with the synchronization mechanism 62. More specifically, when the lock shaft 102 is in the second position, the segmented geared portion 104 engages splines 98 on the worm gear shaft 92. It will be understood that the above example merely illustrates one mechanism of permitting and inhibiting movement of the synchronization mechanism 62 and that the lockout mechanism 64 may be selectively coupled with the synchronization mechanism 62 in any suitable manner.

[0025] As illustrated in Figure 8, the lockout mechanism 64 may be positioned perpendicular to the worm gear shaft 92 at any appropriate location. Regardless of the orientation of the lockout mechanism 64; when it is desired to inhibit the movement of the movable element of the thrust reverser, a user may operate the handle 110 to place the lockout mechanism 64 into the inhibit condition. When the lockout mechanism 64 is in the inhibit condition, the segmented geared portion 104 engages the splines 98 on the worm gear shaft 92 to inhibit movement of the worm gear shaft 92. With the worm gear shaft 92 locked, the synchronization mechanism 62 is prevented from rotating. Locking the synchronization mechanism 62 prevents the lead screw 80 from rotating within and locks the actuator 52 from translating.

[0026] In this manner, when the lockout mechanism 64 is in the inhibit condition, the lockout mechanism 64 locks out each of the multiple actuators 52 operably coupled to the synchronization mechanism 62. Because the worm gear shaft 92 is coupled with the lead screw 80 and because the worm gear shafts 92 of two or more such actuators 52 are connected together, the lockout mechanism 64 may prevent motion of the other actuators 52. In this manner, the lockout mechanism 64 locks out each of the multiple actuators operably coupled to the synchronization mechanism. The locking force is shared with the other actuators 52 through the synchronization mechanism 62 thus locking all actuators 52 in the system.

[0027] To disengage the lockout mechanism 64 a user may simply turn the handle 110 such that the lock out mechanism 64 is moved to the first position where the flat face 106 confronts the worm gear shaft 92 and the lock shaft 102 does not engage the worm gear shaft 92, thus allowing free rotation of the worm gear shaft 92. Once the lockout mechanism 64 is put into the permit condition, the worm gear shaft 92 may move and the actuators 52 may be permitted to move.

[0028] The embodiments described above provide for a variety of benefits including that movement of the movable element of the thrust reverser may be inhibited for crew safety. The above described embodiments disable the thrust reverser actuation system from translation during maintenance activities to provide enhanced safety during maintenance with minimum impact on installation, weight, and the envelope of the system.

[0029] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.