landing gear

Abstract

To provide a landing gear of an aircraft, which is configured so that a bending moment generated in a wheel support part becomes smaller.SOLUTION: A landing gear 10 is provided with: a wheel support part 16 that has a first part supporting a wheel 14 rollably and a second part extending in a direction of an axis line of the first part from the first part toward a fuselage and supporting the first part rotatably with the axis line as a center; an oscillatably supporting part oscillatably supporting the second part of the wheel support part 16 with respect to the fuselage; a retraction actuator 42 that oscillates the wheel support part 16 so that the wheel 14 is stored in the fuselage and the wheel 14 is expanded from the fuselage; a brace 22 mounted on the fuselage to support the wheel support part 16; and a joint 20 connecting the brace 22 to the first part of the wheel support part 16, where the joint 20 is arranged closer to the wheel 14 than the oscillatably supporting part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to aircraft landing gear. [Background technology]

[0002] Patent Document 1 shows a landing gear (also called a landing gear) for an aircraft. The landing gear retracts and deploys wheels into and from the fuselage. In this landing gear, the wheels are supported by a wheel support portion. The wheel support portion has a strut. The strut has a cylinder and a piston rod. The piston rod supports the wheel so that it can roll. The cylinder is supported so that it can swing by a swing support portion of the fuselage. The cylinder is also supported by a brace. The brace is connected to the cylinder via a collar. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 3,086,733 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the structure of Patent Document 1, the collar is positioned above the piston rod. In other words, the collar is positioned away from the wheel in the vertical direction. This increases the bending moment generated in the wheel support part. It is preferable that the moment generated in the strut be small.

[0005] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] An aspect of the present invention is a landing gear comprising: a wheel support part having a first part that supports a wheel so that it can roll; and a second part that extends from the first part toward the airframe in the direction of the axis of the first part and supports the first part so that it can rotate around the axis; a swing support part that swingably supports the second part of the wheel support part with respect to the airframe; a retract actuator that swings the wheel support part to store the wheel in the airframe and deploy the wheel from the airframe; a brace attached to the airframe and supporting the wheel support part; and a joint that connects the brace to the first part of the wheel support part, wherein the joint is positioned closer to the wheel than the swing support part. [Effects of the Invention]

[0007] According to the present invention, the bending moment generated in the wheel support portion can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a landing gear according to a first embodiment. [Figure 2] FIG. 2 is a right side view of the landing gear with the wheels deployed outside the aircraft. [Figure 3] FIG. 3 is a view of the landing gear with the wheels deployed outside the aircraft body, as seen from the direction of arrow III in FIG. [Figure 4] FIG. 4 is a right side view of the landing gear with the wheels retracted inside the fuselage. [Figure 5] FIG. 5 is a view of the landing gear with the wheels retracted inside the fuselage, viewed from the direction of arrow V in FIG. [Figure 6] FIG. 6 is a schematic diagram for explaining a bending moment acting on the wheel support portion of the landing gear according to the first embodiment. [Figure 7] FIG. 7 is a schematic diagram for explaining the bending moment acting on the wheel support portion of a conventional landing gear. [Figure 8] FIG. 8 is a perspective view of a landing gear according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The landing gear 10 described herein is located in the nose of the aircraft.

[0010] [1 First Embodiment] [1-1 Configuration of landing gear 10]

[0011] FIG. 1 is a perspective view of a landing gear 10 according to a first embodiment. FIG. 1 is a perspective view of the landing gear 10 with the wheels 14 deployed outside the fuselage 12. FIG. 2 is a right side view of the landing gear 10 with the wheels 14 deployed outside the fuselage 12. FIG. 3 is a view of the landing gear 10 with the wheels 14 deployed outside the fuselage 12, as viewed from the direction of arrow III in FIG. 2. FIG. 4 is a right side view of the landing gear 10 with the wheels 14 stored inside the fuselage 12. FIG. 5 is a view of the landing gear 10 with the wheels 14 stored inside the fuselage 12, as viewed from the direction of arrow V in FIG. 4.

[0012] The landing gear 10 according to the first embodiment includes wheels 14, wheel supports 16, a retraction mechanism 18, a joint 20, a brace 22, and a shimmy damper 24. An aircraft equipped with this type of landing gear 10 turns left and right by changing the direction of the front wheels (wheels 14) by adjusting the braking force of other landing gears 10 arranged on the left and right rear sides of the fuselage 12 (FIGS. 2 and 4).

[0013] The wheel support portion 16 supports the wheel 14 so that it can roll, and extends from the wheel 14 toward the vehicle body 12. The wheel support portion 16 is swingable. The wheel support portion 16 has a fork 26 and a strut 28. The components of the wheel support portion 16 are arranged in the following order from the wheel 14 toward the center of swing of the wheel support portion 16 (shaft 46, axis 58): wheel 14, fork 26, strut 28. Each of the forks 26 and struts 28 is arranged along the axis 30 of the wheel support portion 16. The fork 26 and the inner rod 38 correspond to a first part of the wheel support portion 16 , and the cylinder 36 corresponds to a second part of the wheel support portion 16 .

[0014] The fork 26 has an axle 34 and legs 32. The legs 32 are U-shaped. The legs 32 sandwich the wheel 14 from both the left and right sides and support the wheel 14 so that it can roll. In this embodiment, the legs 32 are supported on both sides, but may be supported on one side. The axle 34 extends from the center of the left and right sides of the legs 32 toward the strut 28. The axle 34 is cylindrical.

[0015] The strut 28 is a damper having a cylinder 36 and an inner rod 38. The components of the strut 28 are arranged in the order of the inner rod 38 and the cylinder 36, from the fork 26 toward the center of swing of the wheel support part 16 (shaft 46, axis 58). The cylinder 36 and the inner rod 38 are each arranged along the axis 30. The cylinder 36 is swingably supported by the shaft 46 of the retraction mechanism 18. The inner rod 38 is partially housed in the cylinder 36. The end of the inner rod 38, which is arranged outside the cylinder 36, is fitted into and fixed to the shaft part 34 of the fork 26. The inner rod 38 is guided by the cylinder 36. The inner rod 38 can reciprocate along the axis 30 relative to the cylinder 36. The inner rod 38 can also rotate around the axis 30 relative to the cylinder 36.

[0016] The retraction mechanism 18 includes a retraction actuator 42, a rod portion 44, a shaft 46 (swing support portion), and an arm 48. As shown in FIG. 3 , the retraction actuator 42 is disposed offset to either the left or right with respect to the wheel support portion 16 and the wheels 14 in the left-right direction (width direction of the fuselage 12). In this embodiment, the retraction actuator 42 is disposed to the left of the wheel support portion 16 and the wheels 14. The retraction actuator 42 is an electric or hydraulic actuator. The retraction actuator 42 moves the rod portion 44 in the fore-and-aft direction of the aircraft. The rod portion 44 extends in the fore-and-aft direction of the aircraft. The front end of the rod portion 44 is connected to the retraction actuator 42. The rear end of the rod portion 44 includes a branch portion 50 that branches into two. The branch portion 50 sandwiches the roller 52 from both the left and right sides and rotatably supports the roller 52. The roller 52 is rotatable about an axis 54 extending in the left-and-right direction. In front of the roller 52 , a hole 56 is formed by the branch 50 and the roller 52 .

[0017] The shaft 46 is attached to the cylinder 36. The shaft 46 extends in the left-right direction. The shaft 46 is composed of two members attached to the left and right sides of the cylinder 36. The shaft 46 is supported by the machine body 12 and is rotatable about an axis 58 extending in the left-right direction. This allows the wheel support unit 16 to swing about the shaft 46 (axis 58) relative to the machine body 12. The arm 48 extends from the shaft 46, which is arranged to the left of the cylinder 36, toward the hole 56. The tip of the arm 48 is inserted into the hole 56. The back surface of the tip of the arm 48 can abut against the roller 52.

[0018] The joint 20 connects the brace 22 to the wheel support portion 16. The joint 20 is positioned closer to the wheel 14 than the shaft 46, which is the center of swing. In this embodiment, the joint 20 is rotatably attached around the axle portion 34 of the fork 26. As a result, the joint 20 connects the brace 22 to the axle portion 34. The joint 20 may also be rotatably attached around the inner rod 38. In this case, the joint 20 connects the brace 22 to the inner rod 38. In a configuration in which the joint 20 is attached to the inner rod 38, the joint 20 is preferably positioned closer to the fork 26 than the cylinder 36. For example, the joint 20 is preferably positioned at the tip of the inner rod 38 and close to the fork 26. The joint 20 has an annular shape and is fitted onto the outer peripheral surface of the axle portion 34. The joint 20 is rotatable around the axis 30 relative to the axle portion 34. The joint 20 has a first support portion 62 and a second support portion 64. The first support portion 62 rotatably supports the brace 22. The second support portion 64 rotatably supports the shimmy damper 24.

[0019] The brace 22 is a link mechanism. The brace 22 has a lower portion 66 and an upper portion 68, which correspond to links. The lower portion 66 is connected to the first support portion 62 of the joint 20. The lower portion 66 is rotatable about an axis 70 of the first support portion 62. The axis 70 is perpendicular to a direction parallel to the axis 30 and to the radial direction of the joint 20. The upper portion 68 is connected to the lower portion 66. The upper portion 68 is rotatable about an axis 72 of a joint portion between the upper portion 68 and the lower portion 66. The axis 72 and the axis 70 are parallel to each other. The upper portion 68 is also connected to a joint 74. The joint 74 is connected to the aircraft body 12. The upper portion 68 is rotatable about an axis 76 of a joint portion between the upper portion 68 and the joint 74. The upper portion 68 is also rotatable about an axis 78 of the joint 74. Axis 76 and axis 72 are parallel. As shown in Figures 1 to 3, when the wheels 14 are deployed outside the fuselage 12, the braces 22 are extended. On the other hand, as shown in Figures 4 and 5, when the wheels 14 are stored inside the fuselage 12, the braces 22 are folded. As shown in Figure 3, the joint 74 is disposed to the right of the wheel support part 16 and the wheels 14 in the left-right direction (the width direction of the fuselage 12).

[0020] For example, as shown in Figure 3, the shimmy damper 24 is attached to the fork 26 and the second support portion 64 of the joint 20. The shimmy damper 24 stabilizes the orientation of the wheel 14 when a lateral force is applied to the wheel 14. The shimmy damper 24 also generates a restoring force that attempts to return the wheel 14 to its original orientation when the wheel 14 swings left or right.

[0021] [1-2 Operation of landing gear 10] The landing gear 10 retracts the wheels 14 from the exterior to the interior of the fuselage 12 in the following manner.

[0022] From the state shown in FIGS. 1 to 3, the retract actuator 42 moves the rod portion 44 forward. The roller 52 pushes the arm 48 forward. As the arm 48 moves forward, the shaft 46 rotates counterclockwise as viewed from the right. As a result, the wheel support portion 16 and the wheel 14 swing counterclockwise as viewed from the right. As the retract actuator 42 continues to operate, the wheel support portion 16 and the wheel 14 gradually approach the vehicle body 12. As shown in FIGS. 4 and 5, the wheel support portion 16 and the wheel 14 are finally stored inside the vehicle body 12.

[0023] As the wheel support portion 16 swings during the process of storing the wheel 14, the lower portion 66 and the upper portion 68 of the brace 22 rotate about their respective axes (axis 70, axis 72, axis 76, axis 78). As a result, the brace 22 is gradually folded.

[0024] The joint 20 is connected to the brace 22. Therefore, as the wheel support portion 16 swings during the retraction process of the wheel 14, a force that rotates the joint 20 about the axis 30 acts on the joint 20. Specifically, a force in the clockwise direction when viewed from the position of the strut 28 acts on the joint 20. The joint 20 and the fork 26 are connected to each other via the shimmy damper 24. Therefore, the joint 20, the shimmy damper 24, the fork 26, the wheel 14, and the inner rod 38 rotate together about the axis 30 relative to the cylinder 36. Therefore, as shown in FIG. 4 , the wheel 14 is retracted into the fuselage 12 with the rolling axis 80 of the wheel 14 extending substantially in the vertical direction.

[0025] [1-3 Effect of landing gear 10] FIG. 6 is a schematic diagram illustrating the bending moment acting on the wheel support portion 16 of the landing gear 10 according to the first embodiment. FIG. 7 is a schematic diagram illustrating the bending moment acting on the wheel support portion 16 of a landing gear 10' of a comparative example. FIG. 7 shows a schematic diagram of the structure of a conventional device. As can be seen by comparing FIG. 6 and FIG. 7, in the landing gear 10, the length L1 from the center of the wheel 14 to the connection portion (position of joint 20) between the wheel support portion 16 and the brace 22 is shorter than the length L2 from the center of the wheel 14 to the connection portion (position of joint 20) between the wheel support portion 16 and the brace 22 of the landing gear 10'.

[0026] As shown in Figures 6 and 7, an upward load F acts on the wheel 14. The load F is divided into a component fa in the direction of the axis 30 of the wheel support portion 16 and a component fn perpendicular to component fa. In the landing gear 10, a bending moment fn·L1 occurs in the wheel support portion 16. In the conventional landing gear 10', a bending moment fn·L2 occurs in the wheel support portion 16. As described above, because the length L1 of the landing gear 10 is smaller than the length L2 of the landing gear 10', the bending moment fn·L1 is smaller than the bending moment fn·L2. Therefore, according to the first embodiment, the bending moment acting on the wheel support portion 16 can be reduced.

[0027] Furthermore, the first embodiment also provides the following effect. For example, apart from the first embodiment, there is a device in which the joint 20 is arranged on the cylinder 36. In such a device, a member (such as a torque arm) that connects the joint 20 and the fork 26 is required to rotate the wheel 14 around the axis of the wheel support unit 16 in response to the retraction (and deployment) of the wheel 14. In contrast, in the first embodiment, the joint 20 is arranged on the inner rod 38 or the fork 26. According to the first embodiment, a member such as a torque arm is not required for the wheel support unit 16. Therefore, according to the first embodiment, an increase in the weight of the vehicle 12 can be suppressed.

[0028] [2 Second embodiment] Fig. 8 is a perspective view of the landing gear 10 according to the second embodiment. Fig. 8 is a perspective view of the landing gear 10 in a state in which the wheels 14 are deployed outside the fuselage 12. In Fig. 8, the same components as those in the first embodiment are assigned the same reference numerals, or the reference numerals of the same components as those in the first embodiment are omitted.

[0029] The landing gear 10 according to the second embodiment includes a wheel 14, a wheel support 16, a retraction mechanism 18, a brace 22, a joint 20, a steering actuator 82, and a worm gear 84. An aircraft equipped with this type of landing gear 10 is steered by controlling the steering actuator 82.

[0030] The steering actuator 82 is fixed to the joint 20. A worm 86 of a worm gear 84 is fixed to the rotation shaft of the steering actuator 82. Meanwhile, a worm wheel 88 of the worm gear 84 is fixed to the periphery of the shaft portion 34 of the fork 26.

[0031] When the steering actuator 82 is operated, the worm 86 rotates, causing the worm wheel 88 to rotate about the axis 30. As the worm wheel 88 rotates, the fork 26 and the wheel 14 rotate about the axis 30. As a result, the wheel 14 is steered.

[0032] In the second embodiment, similarly to the first embodiment, the joint 20 is attached to the periphery of the shaft 34 of the fork 26. Therefore, according to the second embodiment, the same effects as those of the first embodiment can be obtained.

[0033] [3 Inventions Obtained from the Embodiments] The invention that can be understood from the above embodiment will be described below.

[0034] An aspect of the present invention is a landing gear (10) comprising: a wheel support (16) having a first portion (26, 38) that supports a wheel (14) in a rollable manner; and a second portion (36) that extends from the first portion toward the fuselage (12) in a direction of an axis (30) of the first portion and supports the first portion rotatably around the axis; a swing support (46) that swingably supports the second portion of the wheel support with respect to the fuselage; a retract actuator (42) that swings the wheel support to store the wheel in the fuselage and deploy the wheel from the fuselage; a brace (22) attached to the fuselage and supporting the wheel support; and a joint (20) that connects the brace to the first portion of the wheel support, wherein the joint is positioned closer to the wheel than the swing support.

[0035] According to the above configuration, the moment generated in the wheel support portion can be reduced.

[0036] In one aspect of the present invention, the wheel support portion has a fork (26) that supports the wheel so that it can roll, and a strut (28) that extends from the fork to the vehicle body, the strut being a damper having a cylinder and an inner rod, the fork and the inner rod being the first part, the cylinder being the second part, the inner rod being connected to the fork, the joint being disposed on the fork and being rotatable around the axis relative to the fork, and a shimmy damper (24) being attached to the fork and the joint, the shimmy damper stabilizing the orientation of the wheel when a lateral force is generated on the wheel and generating a restoring force that attempts to return the wheel to its original position when the wheel swings left or right.

[0037] According to the above configuration, since a member such as a torque arm is not required in the wheel support section, an increase in the weight of the vehicle can be suppressed.

[0038] In one aspect of the present invention, the wheel support portion has a fork that supports the wheel so that it can roll, and a strut extending from the fork to the vehicle body, the strut being a damper having a cylinder and an inner rod, the fork and the inner rod being the first part, the cylinder being the second part, the inner rod being connected to the fork, the joint being disposed on the fork and rotatable around the axis relative to the fork, a steering actuator (82) being attached to the joint, and the steering actuator steers the wheel by changing the orientation of the fork relative to the joint.

[0039] According to the above configuration, since a member such as a torque arm is not required in the wheel support section, an increase in the weight of the vehicle can be suppressed.

[0040] In one aspect of the present invention, the wheel support portion has a fork that supports the wheel so that it can roll, and a strut extending from the fork to the vehicle body, the strut being a damper having a cylinder (36) and an inner rod (38), the fork and the inner rod being the first part, the cylinder being the second part, the inner rod being connected to the fork, the joint being positioned on the inner rod closer to the fork than the cylinder and being rotatable around the axis relative to the inner rod, and a shimmy damper being attached to the fork and the joint, the shimmy damper stabilizing the orientation of the wheel when a lateral force is applied to the wheel and generating a restoring force that attempts to return the wheel to its original position when the wheel sways left and right.

[0041] According to the above configuration, since a member such as a torque arm is not required in the wheel support section, an increase in the weight of the vehicle can be suppressed.

[0042] In one aspect of the present invention, the wheel support portion has a fork that supports the wheel so that it can roll, and a strut extending from the fork to the vehicle body, the strut being a damper having a cylinder and an inner rod, the fork and the inner rod being the first part, the cylinder being the second part, the inner rod being connected to the fork, the joint being positioned on the inner rod closer to the fork than the cylinder and rotatable around the axis relative to the inner rod, a steering actuator attached to the joint, and the steering actuator steers the wheel by changing the orientation of the fork relative to the joint.

[0043] According to the above configuration, since a member such as a torque arm is not required in the wheel support section, an increase in the weight of the vehicle can be suppressed.

[0044] In an aspect of the present invention, the wheel support portion and the wheel may be disposed in the width direction of the fuselage between the portion (74) where the brace is connected to the fuselage and the retract actuator.

[0045] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0046] 10...Landing gear 12...Aircraft 14...Wheel 16...Wheel support portion 20...Joint 22...Brace 24...Shimmy damper 26...Fork (first part of wheel support) 28...Strut 30...Axis 36... Cylinder (second part of wheel support) 38...Inner rod (first part of wheel support) 42...Retract actuator 46...Shaft (swing support part) 82...Steering actuator

Claims

1. a wheel support unit having a first portion that supports a wheel so that the wheel can roll, and a second portion that extends from the first portion toward the aircraft body in a direction of the axis of the first portion and supports the first portion so that the wheel can rotate about the axis; a swing support part that swingably supports the second part of the wheel support part with respect to the vehicle body; a retract actuator that swings the wheel support portion to store the wheel in the airframe and deploy the wheel from the airframe; a brace attached to the airframe and supporting the wheel support portion; a joint connecting the brace to the first portion of the wheel support; A landing gear comprising: The joint is positioned closer to the wheel than the swing support.

2. 2. A landing gear system according to claim 1, The wheel support portion is a fork that supports the wheel so that it can roll; a strut extending from the fork to the fuselage; and The strut is a damper having a cylinder and an inner rod, the fork and the inner rod are the first portion, the cylinder is the second portion; The inner rod is connected to the fork, the joint is disposed on the fork and is rotatable about the axis relative to the fork; a shimmy damper attached to the fork and the joint; The shimmy damper is a landing gear that stabilizes the orientation of the wheel when a lateral force is generated on the wheel, and generates a restoring force that attempts to return the wheel to its original position when the wheel swings left or right.

3. 2. A landing gear system according to claim 1, The wheel support portion is a fork that supports the wheel so that it can roll; a strut extending from the fork to the fuselage; and The strut is a damper having a cylinder and an inner rod, the fork and the inner rod are the first portion, the cylinder is the second portion; The inner rod is connected to the fork, the joint is disposed on the fork and is rotatable about the axis relative to the fork; A steering actuator is attached to the joint; The steering actuator steers the wheels by changing the orientation of the forks relative to the joints.

4. 2. A landing gear system according to claim 1, The wheel support portion is a fork that supports the wheel so that it can roll; a strut extending from the fork to the fuselage; and The strut is a damper having a cylinder and an inner rod, the fork and the inner rod are the first portion, the cylinder is the second portion; The inner rod is connected to the fork, the joint is disposed on the inner rod closer to the fork than the cylinder, and is rotatable about the axis relative to the inner rod; a shimmy damper attached to the fork and the joint; The shimmy damper is a landing gear that stabilizes the orientation of the wheel when a lateral force is generated on the wheel, and generates a restoring force that attempts to return the wheel to its original position when the wheel swings left or right.

5. 2. A landing gear system according to claim 1, The wheel support portion is a fork that supports the wheel so that it can roll; a strut extending from the fork to the fuselage; and The strut is a damper having a cylinder and an inner rod, the fork and the inner rod are the first portion, the cylinder is the second portion; The inner rod is connected to the fork, the joint is disposed on the inner rod closer to the fork than the cylinder, and is rotatable about the axis relative to the inner rod; A steering actuator is attached to the joint; The steering actuator steers the wheels by changing the orientation of the forks relative to the joints.

6. 2. A landing gear system according to claim 1, A landing gear in which, in the width direction of the airframe, the wheel support portion and the wheel are arranged between the portion where the brace is connected to the airframe and the retract actuator.

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