A tail wheel follower mechanism for solar powered aircraft

Abstract

The present invention discloses a tail wheel follower mechanism for a solar powered aircraft, comprising: an extended axle, a first locking structure, a second locking structure, a first cable, a second cable, a follower pad, a follower steering shaft, a rudder beam and a tail wheel. The extended axle is installed on the tail wheel; the first locking structure and the second locking structure connect the extended axle and the tail wheel together; the tail wheel is located below the vertical tail main beam; the follower steering shaft passes through the follower pad and is installed below the follower pad; the follower pad is installed below the rudder beam; the first cable and the second cable are respectively connected to the same side end portions of the extended axle and the follower steering shaft.

Description

Technical Field

[0001] The invention relates to the field of solar aircraft landing gear, in particular to a tail wheel follower mechanism of a solar aircraft. Background Art

[0002] At present, most of the landing gears of solar aircraft do not have a steering function. Therefore, in order to ensure that the solar aircraft does not run off the runway during taxiing and landing, extremely high requirements are placed on flight control and the site. At the same time, the active steering mechanism of the landing gear commonly used in traditional aircraft needs to be equipped with a hydraulic or motor system for steering drive, which has the problems of heavy structural weight, high manufacturing cost, and complex installation and repair. Since solar aircraft need to fly for an ultra-long flight time, the requirements for structural weight are extremely stringent. The existing landing gear steering mechanism is difficult to meet the actual use requirements of solar aircraft. Therefore, the present invention adopts a follow-up mechanism to use the deflection of the rudder surface to drive the tail wheel to achieve the steering function.

[0003] The tail wheel follower mechanism is mainly used for steering tasks such as infield transfer, ground taxiing, take-off, and landing of solar aircraft. It has the characteristics of simple structure, low weight, high reliability, convenient maintenance and repair, and low cost. Summary of the invention

[0004] The technical problem solved by the present invention is: compared with the prior art, a tail wheel following mechanism for a solar aircraft is provided, which has the function of the tail wheel rotating with the rudder surface, and the steering of the tail wheel can be adjusted by controlling the rudder surface angle, so that the solar aircraft has the ability to turn autonomously, and can independently complete the solar aircraft's infield transfer, ground taxiing, take-off, landing and other turning tasks.

[0005] The objective of the present invention is achieved through the following technical solutions: A tail wheel follower mechanism for a solar aircraft, comprising: an extended axle, a first locking structure, a second locking structure, a first cable, a second cable, a follower pad, a follower steering shaft, a rudder beam and a tail wheel; wherein the extended axle is installed on the tail wheel; the first locking structure and the second locking structure connect the extended axle and the tail wheel together; the tail wheel is located below the vertical tail main beam; the follower steering shaft passes through the follower pad and is installed at the bottom of the follower pad; the follower pad is installed below the rudder beam; the first cable connects one end of the extended axle and one end of the follower steering shaft; the second cable connects the other end of the extended axle and the other end of the follower steering shaft.

[0006] In the tail wheel follower mechanism for the solar aircraft, the extended axle is made of aluminum alloy and is divided into three sections, namely the first threaded section, the axle section and the second threaded section.

[0007] In the tail wheel follower mechanism for the solar aircraft, the first thread segment is an M4-M6 external thread, and a through hole is formed at the end thereof, and the diameter of the through hole ranges from 2mm to 4mm.

[0008] In the tail wheel follower mechanism for the solar aircraft, the wheel axle section is a round rod with a diameter ranging from 4mm to 6mm.

[0009] In the tail wheel follower mechanism for the solar aircraft, the second thread segment is an M4-M6 external thread, and a through hole is formed at the end thereof, and the diameter of the through hole ranges from 2mm to 4mm.

[0010] In the tail wheel follower mechanism for the solar aircraft, the first locking structure and the second locking structure are made of standard parts, both consisting of a M4-M6 self-locking nut and a circular gasket with a diameter of 4mm-6mm.

[0011] In the tail wheel follower mechanism for the solar aircraft, the first pull wire and the second pull wire are made of materials with small elongation, and are ensured to be symmetrical about the middle plane of the vertical tail.

[0012] In the tail wheel follower mechanism for the solar aircraft, the follower pad is made of a light and high-strength plastic material, and has a ring structure to reduce weight, with through holes on both sides.

[0013] In the tail wheel follower mechanism for the solar aircraft, the follower steering shaft is made of aluminum alloy material, bonded to the through hole with epoxy adhesive, and the lengths of the follower steering shaft exposed at both ends are equal.

[0014] In the above-mentioned tail wheel follower mechanism for solar aircraft, when the rudder surface rotates a certain angle around the rudder surface rotation center, one end (or the other end) of the follower steering shaft pulls one end (or the other end) of the extended wheel shaft through the first pull wire (or the second pull wire), driving the tail wheel to rotate a certain angle around the tail wheel rotation center at the same time.

[0015] In the tail wheel follower mechanism for the solar aircraft, different follower ratios can be achieved by adjusting the length of the extended wheel axle and the follower steering shaft.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] (1) The present invention integrates an extended wheel axle, a first locking structure, a second locking structure, a first cable, a second cable, a follower pad, a follower steering shaft, a rudder beam and a tail wheel into a whole, and adjusts the steering of the tail wheel by controlling the angle of the rudder surface. The tail wheel has the function of rotating with the rudder surface, and the steering of the tail wheel can be adjusted by controlling the angle of the rudder surface, so that the solar-powered aircraft has the ability to turn autonomously, and can independently complete the turning tasks of the solar-powered aircraft such as infield transfer, ground taxiing, take-off, and landing. The present invention has the characteristics of low cost, light weight, high reliability, and convenient use and maintenance.

[0018] (2) The present invention uses the original tail wheel and rudder beam structure of the solar aircraft for improved design, and has the characteristics of simple structure, low weight, high reliability, convenient maintenance and repair, and low cost.

[0019] (3) The present invention can achieve different follow-up ratios by adjusting the length of the extended wheel axle and the follow-up steering shaft.

[0020] (4) In the present invention, within the range of 5° to 20° of rudder surface deflection (actual rudder surface deflection range), the following ratio is close to linear. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a tail wheel follower mechanism for a solar powered aircraft provided by an embodiment of the present invention is shown;

[0022] Figure 2 A bottom view schematic diagram of a tail wheel follower mechanism for a solar powered aircraft provided by an embodiment of the present invention is shown;

[0023] Figure 3 A schematic diagram of a lengthened wheel axle in a tail wheel follower mechanism for a solar powered aircraft provided by an embodiment of the present invention is shown;

[0024] Figure 4 A schematic diagram of a follower pad in a tail wheel follower mechanism for a solar aircraft provided by an embodiment of the present invention is shown;

[0025] Figure 5 A schematic diagram of a follow-up steering shaft in a tail wheel follow-up mechanism for a solar-powered aircraft provided by an embodiment of the present invention is shown;

[0026] Figure 6 The tail wheel follower ratio curve and linearity under certain conditions in the tail wheel follower mechanism for a solar aircraft provided by an embodiment of the present invention are shown. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0028] Figure 1A schematic diagram of a tail wheel follower mechanism for a solar aircraft provided by an embodiment of the present invention is shown. Figure 2 FIG. 1 is a bottom view schematic diagram of a tail wheel follower mechanism for a solar powered aircraft provided by an embodiment of the present invention. Figure 1 and Figure 2 As shown, the follower mechanism includes: an extended wheel shaft 1, a first locking structure 2, a second locking structure 3, a first cable 4, a second cable 5, a follower pad 6, a follower steering shaft 7, a rudder beam 8 and a tail wheel 9. Among them,

[0029] The tail wheel 9 is mounted on the extended axle 1. The first locking structure 2 and the second locking structure 3 connect the extended axle 1 and the tail wheel 9 together. Specifically, the first locking structure is mounted on one end of the extended axle and close to one side of the tail wheel; the second locking structure is mounted on the other end of the extended axle and close to the other side of the tail wheel.

[0030] The tail wheel 9 is installed below the vertical tail. Specifically, the sleeve on the tail wheel 9 is bonded to the inner side below the vertical tail main beam by epoxy adhesive.

[0031] The follower steering shaft 7 passes through the through hole on the follower pad and is located at the bottom of the follower pad. Specifically, the follower steering shaft and the follower pad are bonded together by epoxy adhesive, and the lengths of the follower steering shafts on both sides are equal.

[0032] The follower pad 6 is installed below the rudder beam. Specifically, the follower pad is bonded to the inner side below the rudder beam 8 by epoxy adhesive, and ensures that the follower steering shaft is parallel to the lengthened wheel axle.

[0033] The first cable 4 connects one end of the extended wheel axle and one end of the follow-up steering shaft. Specifically, one end of the first cable is connected to the hole at one end of the extended wheel axle, and the other end is connected to the hole on the same side of the follow-up steering shaft;

[0034] The second cable 5 connects the other end of the extended wheel axle and the other end of the follow-up steering shaft. Specifically, one end of the first cable is connected to the hole at one end of the extended wheel axle, and the other end is connected to the hole on the same side of the follow-up steering shaft, and the lengths of the first cable and the second cable are equal. The first cable and the second cable are limited by nuts installed on both sides of the extended wheel axle.

[0035] Figure 3 The schematic diagram of the extended axle in the tail wheel follower mechanism for a solar aircraft provided by an embodiment of the present invention is shown. Since the tail wheel load is small, the extended axle is made of aluminum alloy material, which can effectively reduce the weight of the structure. At the same time, it is composed of three sections, namely the first thread section 12, the axle section 13 and the second thread section 14. Among them, the first thread section and the second thread section are both M4-M6 external threads, and through holes 11 and 15 are opened at the ends, which are the connection interfaces of the first cable and the second cable, and the diameter of the through holes ranges from 2mm to 4mm.

[0036] In the above implementation, the first locking structure and the second locking structure are both composed of a self-locking nut of M4-M6 and a circular gasket with a diameter of 4mm-6mm.

[0037] In the above implementation, the first and second pull wires are made of materials with smaller elongation and are ensured to be symmetrical about the middle plane of the vertical tail. In this embodiment, polyethylene pull wires are used.

[0038] Figure 4 The following diagram of the follower pad in the tail wheel follower mechanism for a solar aircraft provided in an embodiment of the present invention is shown. The follower pad 6 is made of a light and high-strength plastic material, and adopts a ring structure to reduce weight. Through holes 61 and 62 are opened on both sides. In this embodiment, PEEK material is used. Specifically, the through holes on both sides are symmetrical about the middle plane of the vertical tail.

[0039] Figure 5 The schematic diagram of the follow-up steering shaft in the tail wheel follow-up mechanism for a solar aircraft provided by an embodiment of the present invention is shown. The follow-up steering shaft 7 is made of aluminum alloy material, and through holes 71 / 72 for passing the first and second cables are opened on both sides. The follow-up steering shaft and the through holes on both sides of the follow-up pad are bonded with epoxy glue, and the exposed lengths of the follow-up steering shaft at both ends are equal. Specifically, the follow-up steering shaft passes through and is bonded with the through holes 61 / 62 on both sides of the follow-up pad with epoxy glue.

[0040] In the above implementation, when the rudder rotates a certain angle around the rotation center of the rudder, one end of the follow-up steering shaft 7 pulls one end of the extended wheel shaft 1 through the first cable 4 (or the second cable 5), driving the tail wheel 9 to rotate a certain angle around the rotation center of the tail wheel at the same time. Specifically, during the rotation process, one side of the cable is in a taut state, and the other side of the cable is slightly loose.

[0041] In the above implementation, different tail wheel rotation follow-up ratios can be achieved by adjusting the extended wheel axle and the follow-up steering shaft 7.

[0042] Figure 6 The figure shows the tail wheel follower ratio curve and linearity of the tail wheel follower mechanism for solar aircraft provided by the embodiment of the present invention under certain conditions. In this embodiment, the length of the extended wheel axle is 300mm, the length of the follower steering shaft is 200mm, and the distance between the center of the vertical tail main beam and the center of the rudder beam is 750mm. At this time, when the rudder surface deflects 5° to 20°, the tail wheel follower ratio is 0.6178, and the R representing the linearity is 0.6178. 2 The value reaches 0.9995, which is very close to linear.

[0043] The mechanism of the present invention has the function of the tail wheel rotating with the rudder surface, and the steering of the tail wheel can be adjusted by controlling the angle of the rudder surface, so that the solar aircraft can have the ability to turn autonomously, and can independently complete the turning tasks such as the solar aircraft's infield transfer, ground taxiing, take-off, and landing. The present invention has the characteristics of low cost, light weight, high reliability, and convenient use and maintenance.

[0044] The embodiments described above are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A tail wheel follower mechanism for a solar powered aircraft, characterized in that: include: An extended wheel axle (1), a first locking structure (2), a second locking structure (3), a first cable (4), a second cable (5), a follower pad (6), a follower steering shaft (7), a rudder beam (8), and a tail wheel (9); wherein: The tail wheel is mounted on the extended wheel axle (1); the extended wheel axle (1) and the tail wheel (9) are connected together by the first locking structure (2) and the second locking structure (3); the tail wheel (9) is mounted below the vertical tail main beam of the solar aircraft; The follow-up steering shaft (7) passes through a follow-up pad (6) installed below the rudder beam (8); the first cable (4) and the second cable (5) are respectively used to connect the two ends of the extended wheel axle (1) and the follow-up steering shaft (7); and the first cable (4) and the second cable (5) are ensured to be symmetrical about the middle plane of the vertical tail.

2. The tail wheel follower mechanism for a solar powered aircraft according to claim 1, characterized in that: The extended wheel axle (1) is divided into three sections, namely a first threaded section (12), a wheel axle section (13) and a second threaded section (14); the middle wheel axle section is used to install the tail wheel, and the first threaded section and the second threaded section on both sides are used to install the first locking structure (2) and the second locking structure (3) and to limit the first pull wire (4) and the second pull wire (5) installed thereon.

3. The tail wheel follower mechanism for a solar powered aircraft according to claim 2, characterized in that: The first thread segment (12) is an M4-M6 external thread, and a through hole (11) is formed at the end thereof, and the diameter of the through hole ranges from 2 mm to 4 mm.

4. The tail wheel follower mechanism for a solar powered aircraft according to claim 2, characterized in that: The wheel axle section (13) is a round rod with a diameter ranging from 4 mm to 6 mm.

5. The tail wheel follower mechanism for a solar powered aircraft according to claim 2, characterized in that: The second thread section (14) is an M4-M6 external thread, and a through hole (15) is formed at the end thereof, and the diameter of the through hole ranges from 2 mm to 4 mm.

6. The tail wheel follower mechanism for a solar powered aircraft according to claim 1, characterized in that: The first locking structure (2) and the second locking structure (3) are made of standard parts, both consisting of a M4-M6 self-locking nut and a circular gasket with a diameter of 4mm-6mm.

7. The tail wheel follower mechanism for a solar powered aircraft according to claim 1, characterized in that: The follower pad adopts an annular structure and is radially provided with a through hole for installing the follower steering shaft, and the through hole is symmetrical with respect to the middle plane of the vertical tail.

8. The tail wheel follower mechanism for a solar powered aircraft according to claim 7, characterized in that: The follow-up steering shaft (7) is bonded to the through hole with epoxy adhesive, and the lengths of the follow-up steering shaft (7) exposed at both ends are equal.

9. The tail wheel follower mechanism for a solar powered aircraft according to claim 1, characterized in that: Different follow-up ratios are achieved by adjusting the length of the extended wheel axle (1) and the follow-up steering shaft (7).

10. The tail wheel follower mechanism for a solar powered aircraft according to claim 1, characterized in that: The first pull wire (4) and the second pull wire (5) are made of a material with an elastic modulus of more than 100 GPa, the extended wheel axle and the follower steering shaft (7) are both made of aluminum alloy; the follower pad (6) is made of a material with a density of 0.9-1.4 kg / m 3 , plastic material with a compressive strength of more than 30MPa.

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