Flying apparatus

Abstract

Provided is a flying apparatus capable of suppressing excessive torque from acting on an engine and on a path along which a drive force of the engine is transmitted.　A flying apparatus 10 comprises: a main rotor 12 serving as a rotor; an engine 30 serving as a drive source; a drive force transmission path unit 20; and a power transmission restriction unit 26. The main rotor 12 is configured to generate thrust by rotating. The engine 30 is configured to rotate the main rotor 12 by being drivingly connected to the main rotor 12. The drive force transmission path unit 20 is configured to transmit rotational drive force from the engine 30 to the main rotor 12. The power transmission restriction unit 26 is configured to restrict the transmission of the rotational drive force in the drive force transmission path unit 20.

Description

flight equipment

[0001] The present invention relates to a flight device, and more particularly to a flight device having a rotor that rotates about a vertical axis.

[0002] Conventionally, there have been known unmanned flying devices capable of flying in the air. Such flying devices are capable of flying in the air by using the thrust of a rotor that rotates around a vertical axis.

[0003] Possible fields of application for such flying devices include, for example, transportation, surveying, and photography. When a flying device is used in such fields, surveying equipment and photography equipment are attached to the flying device. By applying the flying device to such fields, it is possible to fly the flying device in areas where humans cannot enter, and transport, photograph, and survey such areas. Inventions related to such flying devices are described, for example, in Patent Document 1 and Patent Document 2.

[0004] In a typical flying device, the rotor rotates using power supplied from a storage battery installed in the flying device. However, since the amount of energy supplied by the storage battery is not always sufficient, flying devices equipped with engines have also appeared to achieve continuous flight over long periods of time. In such flying devices, the driving force of the engine rotates a generator, and the rotor is driven by the power generated by the generator. By using such a flying device for photography and surveying, it is possible to perform photography, surveying, and transportation over a wide area. An example of a flying device equipped with an engine is described in Patent Document 3.

[0005] JP 2012-51545 A JP 2014-240242 A JP 2011-251678 A

[0006] However, the inventions described in the above-mentioned patent documents leave room for improvement in terms of improving the safety of the flight device during flight.

[0007] Specifically, in an engine-equipped flight device, the rotational driving force generated by the operation of the engine is transmitted to the rotor via a driving force transmission system including shafts, gears, etc. Therefore, the shafts and gears that make up the driving force transmission system are designed to withstand the torque generated by the engine.

[0008] On the other hand, when a flying device flies, it is possible that the rotor will come into contact with an obstacle such as a tree or a building. In this case, the rotor's rotation will stop or slow down, generating a reverse torque that is input to the engine via the driving force transmission system. Therefore, the reverse torque may damage the driving force transmission system or the engine.

[0009] The present invention has been made in consideration of these problems, and an object of the present invention is to provide a flying device that can prevent excessive torque from acting on the engine and the path through which its driving force is transmitted.

[0010] A flying device according to an embodiment of the present invention is a flying device that floats in the air and is equipped with a rotor, a driving source, a driving force transmission path section, and a power transmission limiting section, wherein the rotor is configured to generate thrust by rotating, the driving source is configured to rotate the rotor by being drivingly connected to the rotor, the driving force transmission path section is configured to transmit a rotational driving force from the driving source to the rotor, and the power transmission limiting section is configured to limit the transmission of the rotational driving force in the driving force transmission path section.

[0011] According to the flying device of the embodiment of the present invention, the power transmission limiting unit limits the transmission of the rotational driving force, thereby preventing the rotational driving force acting on the driving force transmission path from becoming excessive.

[0012] FIG. 1 is a perspective view of a flying device according to an embodiment of the present invention; FIG. 2 is a top view of a flying device according to an embodiment of the present invention; FIG. 3 is a side view of a flying device according to an embodiment of the present invention; FIG. 4 is a top view of an engine mounted on a flying device according to an embodiment of the present invention; FIG. 5 is a cross-sectional view of an engine mounted on a flying device according to an embodiment of the present invention; FIG. 6 is a perspective view of a flying device according to an embodiment of the present invention, showing the engine, a driving force transmission path, and a main rotor; FIG. 7 is a perspective view of a flying device according to an embodiment of the present invention, showing the driving force transmission path and a main rotor; FIG. 8 is a perspective view of a flying device according to an embodiment of the present invention, showing a power conversion unit and its vicinity; FIG. 9 is a perspective view of a flying device according to an embodiment of the present invention, showing a first example of a power transmission limiter; FIG. 10 is a perspective view of a flying device according to an embodiment of the present invention, showing a second example of a power transmission limiter; FIG. 11 is a perspective view of a flying device according to an embodiment of the present invention, showing a third example of a power transmission limiter.

[0013] A flying device 10 according to an embodiment of the present invention will be described in detail below with reference to the drawings. In the following description, "forward" refers to the direction in which the flying device 10 moves forward, and "backward" refers to the opposite direction of "forward." Furthermore, "left and right" refers to the left and right when viewing the flying device 10 from the front. Furthermore, in the following description, identical components will generally be assigned the same reference numerals, and repeated explanations will be omitted.

[0014] Here, the correspondence between the claims and this embodiment will be explained. An example of a rotor described in the claims is the main rotor 12. An example of a drive source described in the claims is the engine 30. An example of a power transmission limiting unit described in the claims is the first torque limiter 261 or the second torque limiter 262.

[0015] The general configuration of the flight device 10 will be described with reference to Figures 1 to 3. Figure 1 is a perspective view of the flight device 10. Figure 2 is a top view of the flight device 10. Figure 3 is a side view of the flight device 10.

[0016] The flight device 10 is a device that floats in the air and mainly comprises a main rotor 12 as a rotor, an engine 30 as a drive source, a driving force transmission path 20, and a power transmission limiter 26.

[0017] The flight device 10 is a device also known as a drone. The flight device 10 is, for example, an engine-equipped drone, specifically a parallel hybrid drone. A parallel hybrid drone is a drone that uses an engine 30 to mechanically rotate a main rotor 12 (described below), which generates lift as the main rotor 12 rotates, allowing the aircraft to float. Furthermore, a parallel hybrid drone has a sub-rotor 13 that controls the position and attitude of the flight device 10 by rotating it with a motor 14 (described below). While the flight device 10 of this embodiment is a parallel hybrid drone, an electric drone or a series hybrid drone may also be used as the flight device 10.

[0018] The main body 11 is the main body that supports each component of the flight device 10 and is made of synthetic resin, metal, or a composite of these. Here, the main body 11 is made of multiple frame-like members. The engine 30, which will be described later, and various electrical components are arranged inside the main body 11. A support 15 extends downward from the main body 11. The support 15 is a part that supports the main body 11 by contacting the landing surface, such as the ground, when the flight device 10 lands. The main body 11 and the support 15 are made of pipe-shaped members such as bent steel pipes.

[0019] A main arm 17 and a sub-arm 18 extend from the main body 11 toward the periphery.

[0020] The main arm 17 is configured to support the main rotor 12 and the power transmission unit 21. The main arm 17 has a first main arm 17A extending leftward from the main body 11 and a second main arm 17B extending rightward from the main body 11.

[0021] The first power conversion unit 22A and the first main rotor 12A are attached to the left end of the first main arm 17A. The second power conversion unit 22B and the second main rotor 12B are disposed to the right end of the second main arm 17B. This configuration will be described later with reference to Figure 6 and subsequent figures.

[0022] The sub-arm 18 is an arm to which the sub-rotor 13 and motor 14, which will be described later, are attached. The sub-arm 18 has sub-arms 18A to 18D. The sub-arm 18A is an arm that extends from the main body 11 toward the front left. The sub-arm 18B is an arm that extends from the main body 11 toward the front right. The sub-arm 18C is an arm that extends from the main body 11 toward the rear left. The sub-arm 18D is an arm that extends from the main body 11 toward the rear right.

[0023] 1 and 2, the main rotor 12 is configured to generate thrust by rotating. The main rotor 12 includes a first main rotor 12A and a second main rotor 12B. The first main rotor 12A and the second main rotor 12B are configured to rotate along a vertical axis.

[0024] The first main rotor 12A is disposed on the left side of the main body 11. The first main rotor 12A is drivingly connected to the crankshaft of the engine 30 via a first shaft 21A and the like.

[0025] The second main rotor 12B is disposed on the right side of the main body 11. The second main rotor 12B is drivingly connected to the engine 30 via a second shaft 21B and the like.

[0026] The first main rotor 12A and the second main rotor 12B rotate in opposite directions at the same rotation speed.

[0027] The engine 30 is configured to be drivingly connected to the main rotor 12 to rotate the main rotor 12. The engine 30 generates power to rotate the first main rotor 12A and the second main rotor 12B. The engine 30 is built into the main body 11. As will be described later, the engine 30 is a so-called opposed engine, and therefore vibrations generated by the engine 30 are small, allowing the flight device 10 to fly stably. The configuration of the engine 30 will be described later with reference to Figure 4, etc.

[0028] 1 and 2 , the sub-rotor 13 is configured to generate an aerodynamic effect by rotating about a vertical axis. In this embodiment, the sub-rotor 13 is configured to adjust the position and attitude of the flight device 10 in the air. Specifically, the sub-rotor 13 includes a first sub-rotor 13A through a fourth sub-rotor 13D. Each of the first sub-rotor 13A through the fourth sub-rotor 13D is composed of two rotors arranged opposite each other. Furthermore, each of the first sub-rotor 13A through the fourth sub-rotor 13D includes rotors arranged in a stacked configuration.

[0029] The first sub-rotor 13A is located on the front left side of the main body 11, connected to the main body 11 via a sub-arm 18A, and rotated by a motor 14A. The second sub-rotor 13B is located on the front right side of the main body 11, connected to the main body 11 via a sub-arm 18B, and rotated by a motor 14B. The third sub-rotor 13C is located on the rear left side of the main body 11, connected to the main body 11 via a sub-arm 18C, and rotated by a motor 14C. The fourth sub-rotor 13D is located on the rear right side of the main body 11, connected to the main body 11 via a sub-arm 18D, and rotated by a motor 14D.

[0030] 1 and 2 , the motors 14 are configured to rotate the sub-rotors 13. The motors 14 include motors 14A to 14D. Motor 14A is attached to the outer end of sub-arm 18A and configured to rotate the first sub-rotor 13A. Motor 14B is attached to the outer end of sub-arm 18B and configured to rotate the second sub-rotor 13B. Motor 14C is attached to the outer end of sub-arm 18C and configured to rotate the third sub-rotor 13C. Motor 14D is attached to the outer end of sub-arm 18D and configured to rotate the fourth sub-rotor 13D. The motors 14 operate by receiving power from a battery (not shown).

[0031] FIG. 4 is a top view showing the engine 30 mounted on the flight device 10.

[0032] 4, the engine 30 is, for example, an opposed-type engine. The engine 30 has a first opposed engine section 30A and a second opposed engine section 30B. The first opposed engine section 30A and the second opposed engine section 30B each constitute an opposed-type engine, as described below. By having multiple opposed engine sections, the output of the engine 30 as a whole can be increased, and sufficient energy required for the flight of the flight device 10 can be obtained.

[0033] In a plan view, the engine 30 is disposed at an incline. Specifically, the engine 30 has a first crankshaft 333 and a second crankshaft 343, which will be described later. The directions in which the first crankshaft 333 and the second crankshaft 343 extend are not parallel to the left-right direction. The first crankshaft 333 is inclined forward toward the right. The second crankshaft 343 is inclined rearward toward the left. With this configuration, the first main rotor 12A, which is drivingly connected to the second crankshaft 343, and the second main rotor 12B, which is drivingly connected to the first crankshaft 333, can be disposed symmetrically in the front-rear direction.

[0034] The second crankshaft 343 is connected to a first driving force transmission path 20A (described later). Specifically, the second crankshaft 343 is connected to a first shaft 21A (described later) so as to be non-rotatable relative to the first shaft 21A. The first crankshaft 333 is connected to a second driving force transmission path 20B (described later). Specifically, the first crankshaft 333 is connected to a second shaft 21B (described later) so as to be non-rotatable relative to the second shaft 21B.

[0035] 5 is a cross-sectional view showing the first opposing engine section 30A mounted on the flight device 10. FIG. 5 is a cross-sectional view taken along the line AA in FIG.

[0036] The first opposed engine section 30A has a first engine section 33 and a second engine section 34. The first engine section 33 and the second engine section 34 form one opposed engine section.

[0037] The cylinder chamber 32 is a space having a substantially cylindrical shape. The cylinder chamber 32 is surrounded by a first cylinder wall 35 and a second cylinder wall 36. The first cylinder wall 35 and the second cylinder wall 36 are walls formed inside the engine block 31. Inside the cylinder chamber 32, a first piston 331 and a second piston 341 are arranged opposite each other and are arranged to reciprocate.

[0038] The first engine section 33 has a first piston 331, a first connecting rod 332, and a first crankshaft 333. The first connecting rod 332 rotatably connects the first piston 331 and the first crankshaft 333 together.

[0039] The second engine section 34 is disposed opposite the first engine section 33. The second engine section 34 has a second piston 341, a second connecting rod 342, and a second crankshaft 343. The second connecting rod 342 rotatably connects the second piston 341 and the second crankshaft 343.

[0040] The extension space 39 is a space that extends laterally and upward from the middle of the cylinder chamber 32 in the front-rear direction.

[0041] The combustion chamber 40 is a space sandwiched between the pistons inside the cylinder chamber 32. The combustion chamber 40 is a space sandwiched between the first piston 331 and the second piston 341 inside the cylinder chamber 32, where an air-fuel mixture is burned.

[0042] The cylinder chamber 32 and the extension space 39 are spaces surrounded by walls formed inside the engine block 31 .

[0043] The extension space 39 is a space surrounded by the first extension wall portion 37 and the second extension wall portion 38. The first extension wall portion 37 is a generally tongue-shaped portion that extends upward from the upper end of the first cylinder wall portion 35 at the rear end of the first cylinder wall portion 35. The second extension wall portion 38 is a generally tongue-shaped portion that extends upward from the upper end of the second cylinder wall portion 36 at the front end of the second cylinder wall portion 36.

[0044] The first opposing engine section 30A having the above-described configuration operates by repeating an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke as follows.

[0045] During the intake stroke, the first piston 331 and the second piston 341 move from the center toward the outside inside the cylinder chamber 32, causing a mixture of fuel and air to be drawn into the cylinder chamber 32.

[0046] During the compression stroke, the inertia of the rotating first crankshaft 333 and second crankshaft 343 pushes the first piston 331 and second piston 341 toward the center, compressing the air-fuel mixture inside the cylinder chamber 32.

[0047] During the combustion stroke, a spark plug (not shown here) ignites in the extension space 39, causing the mixture to burn inside the extension space 39 and the combustion chamber 40, thereby pushing the first piston 331 and the second piston 341 to their outer ends, which are at bottom dead center.

[0048] During the exhaust stroke, the inertia of the rotating first crankshaft 333 and second crankshaft 343 pushes the first piston 331 and second piston 341 inward, and the burned gas present inside the cylinder chamber 32 is expelled to the outside.

[0049] The configuration and operation of the second opposing engine section 30B shown in FIG. 4 are similar to the configuration and operation of the first opposing engine section 30A described above.

[0050] FIG. 6 is a perspective view showing the engine 30, the driving force transmission path 20, and the main rotor 12. As shown in FIG.

[0051] The driving force transmission path 20 is configured to transmit rotational driving force from the engine 30 to the main rotor 12. The driving force transmission path 20 has a power transmission part 21, a power conversion part 22, and a second power transmission part 23. Here, the driving force transmission path 20 disposed on the left side is a first driving force transmission path 20A. The driving force transmission path 20 disposed on the right side is a second driving force transmission path 20B.

[0052] The first driving force transmission path 20A is configured to transmit the rotational driving force of the engine 30 to the first main rotor 12A. The first driving force transmission path 20A has a first shaft 21A, a first power conversion unit 22A, a first vertical drive shaft 23A, and a power transmission limiting unit 26 (described later). The power transmission limiting unit 26 will be described later with reference to Figure 9 and subsequent figures.

[0053] The first shaft 21A is configured to transmit rotational driving force from the engine 30 to the first power conversion unit 22A. The first shaft 21A is connected to the second crankshaft 343 of the engine 30 and extends toward the left side. The first shaft 21A is a tubular member made of, for example, a metal such as iron or aluminum, a carbon material, a resin material, or a composite material containing these. The same applies to the second shaft 21B.

[0054] The first power conversion unit 22A is configured to convert the direction of the rotational driving force and to transmit the rotational driving force to the first vertical drive shaft 23A. A specific configuration of the first power conversion unit 22A will be described later with reference to FIG. 8 etc.

[0055] The first vertical drive shaft 23A is configured to transmit a rotational drive force to the first main rotor 12A. The specific configuration of the first vertical drive shaft 23A will be described later with reference to FIG.

[0056] The second driving force transmission path 20B is configured to transmit the rotational driving force of the engine 30 to the second main rotor 12B. The second driving force transmission path 20B has a second shaft 21B, a second power conversion unit 22B, and a power transmission limiting unit 26 (described later). The configuration of each component included in the second driving force transmission path 20B is the same as that of the first driving force transmission path 20A. That is, the configuration of the second shaft 21B is the same as that of the first shaft 21A. The configuration of the second power conversion unit 22B is the same as that of the first power conversion unit 22A. The configuration of the second vertical drive shaft 23B is the same as that of the first vertical drive shaft 23A.

[0057] Fig. 7 is a perspective view showing the first driving force transmission path 20A and the first main rotor 12A. Fig. 8 is a perspective view showing the power conversion unit 22 and its vicinity. Fig. 8 does not show the cover that constitutes the first power conversion unit 22A.

[0058] 7 and 8, as described above, first driving force transmission path 20A includes first shaft 21A, first power conversion part 22A, and first vertical drive shaft 23A. Each component constituting first driving force transmission path 20A is rotatably housed in case 29 shown in FIG.

[0059] 7, the left end of the first shaft 21A is connected to the horizontal drive shaft 28 via a coupling 27. The left end of the horizontal drive shaft 28 is connected to the first power conversion unit 22A. Here, the first power conversion unit 22A is covered and supported by a case 29. Therefore, the first power conversion unit 22A, the first vertical drive shaft 23A, and the first main rotor 12A are supported by the first main arm 17A shown in FIG. 1 via the case 29.

[0060] Referring to FIG. 8 , the first power conversion unit 22A is a device that converts the transmission direction of the rotational driving force generated by the engine 30. Here, the first driving force transmission path 20A is configured to convert the transmission direction of the rotational driving force generated by the engine 30 from a horizontal direction to a vertical direction. Furthermore, the first power conversion unit 22A may be a device that changes the rotational speed and torque of this rotational driving force. Specifically, the first power conversion unit 22A is a cross-axis gear having a drive gear 24 and a driven gear 25. The drive gear 24 is a gear fixed to the left end of the horizontal drive shaft 28 so as not to rotate relative to the horizontal drive shaft 28. The driven gear 25 is a substantially circular gear with teeth formed at equal intervals along its periphery. The teeth extend radially along the periphery of the driven gear 25. The teeth formed on the periphery of the driven gear 25 mesh with the teeth formed on the periphery of the drive gear 24. The rotation axis of the drive gear 24, which extends horizontally, is perpendicular to the rotation axis of the driven gear 25, which extends vertically. Similarly, the extension direction of the first shaft 21A, which extends horizontally, is perpendicular to the extension direction of the first vertical drive shaft 23A, which extends vertically.

[0061] The first vertical drive shaft 23A is a generally rod-shaped member that extends to connect the center of the underside of the driven gear 25 and the center point of the first main rotor 12A. The first vertical drive shaft 23A is a cylindrical member made of metal or the like and having a central axis that extends in the up-down direction.

[0062] In the first driving force transmission path 20A, the first power conversion unit 22A transmits the rotational driving force so that the rotational speed of the first vertical drive shaft 23A is slower than the rotational speed of the first shaft 21A. Specifically, the gear ratio between the driven gear 25 and the drive gear 24 is set so that the first power conversion unit 22A functions as a reducer. For example, the gear ratio between the driven gear 25 and the drive gear 24 is 4:1. That is, the number of teeth formed on the periphery of the drive gear 24 is ¼ the number of teeth formed on the periphery of the driven gear 25. When the flight device 10 is flying, the rotational driving force is transmitted from the drive gear 24 to the driven gear 25. Therefore, when the rotational driving force is transmitted from the drive gear 24 to the driven gear 25, the rotational speed is reduced to ¼ and the rotational torque is increased by four times.

[0063] The second power conversion unit 22B shown in FIG. 6 also has a similar configuration to the first power conversion unit 22A described above.

[0064] FIG. 9 is a perspective view showing a first embodiment of the power transmission limiting portion 26. As shown in FIG.

[0065] In the flight device 10 of this embodiment, a power transmission limiting unit 26 is installed in a middle portion of the first driving force transmission path 20A, which transmits the rotational driving force from the engine 30 to the first main rotor 12A. The power transmission limiting unit 26 is a component that limits the transmission of torque in a middle portion of the first driving force transmission path 20A.

[0066] Here, a first torque limiter 261 serving as the power transmission limiting section 26 is disposed midway along the horizontal drive shaft 28 .

[0067] The first torque limiter 261 is disposed in the middle portion of the horizontal drive shaft 28. The first torque limiter 261 has a tolerance ring (not shown) inside it. When the torque acting on the first torque limiter 261 exceeds a threshold torque (described later), the tolerance ring slips. This causes the torque transmitted by the first torque limiter 261 to be equal to or less than the threshold torque. In other words, the first torque limiter 261 has the function of limiting the torque transmitted via the horizontal drive shaft 28 to a predetermined threshold torque or less. A second torque limiter 262 (described later) has a configuration similar to that of the first torque limiter 261.

[0068] The threshold torque is set to a magnitude that can protect the first driving force transmission path section 20A and the engine 30. As an example, the threshold torque is set to be equal to or greater than the torque transmitted from the engine 30 side to the first main rotor 12A side, and equal to or less than the counter torque transmitted from the first main rotor 12A side to the first opposing engine section 30A side. In this way, the torque of the engine 30 can be effectively transmitted to the main rotor 12, and the engine 30 and the like can be protected from the counter torque described below.

[0069] Specifically, the engine 30 generates torque, which is a rotational driving force, by repeating an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. The torque generated by the engine 30 during the expansion stroke is set to be the largest among all the strokes. The threshold torque is set to be greater than the torque generated by the engine 30 during the expansion stroke. This allows the horizontal drive shaft 28 to transmit all of the rotational driving force generated by the engine 30 to the first main rotor 12A.

[0070] On the other hand, if the first main rotor 12A comes into contact with an obstacle while the flight device 10 is flying, a reverse torque is transmitted from the first main rotor 12A toward the engine 30. This reverse torque occurs in the opposite direction to the rotational direction of the torque described above. This reverse torque is larger than the maximum torque generated by the engine 30, and in some cases can reach several times that value. In this embodiment, the threshold torque is set smaller than the reverse torque. This makes it possible to prevent the reverse torque from being transmitted to the engine 30.

[0071] The function of the first torque limiter 261 will now be described. The aforementioned reverse torque is transmitted to the engine 30 via the first vertical drive shaft 23A, the first power conversion unit 22A, the horizontal drive shaft 28, the coupling 27, and the first shaft 21A. Therefore, unless some countermeasure is taken, this reverse torque could damage the first power conversion unit 22A, the engine 30, and the like. In this embodiment, the first torque limiter 261, which serves as the power transmission limiter 26, is disposed on the horizontal drive shaft 28. Therefore, even if the first main rotor 12A comes into contact with an obstacle or the like during flight of the flight device 10, causing a reverse torque to act toward the engine 30, the reverse torque is kept below the threshold torque on the horizontal drive shaft 28. This suppresses the reverse torque acting on the engine 30, thereby protecting the engine 30 from the reverse torque.

[0072] In the flight device 10 shown in FIG. 9 , the first torque limiter 261 is mounted only on the horizontal drive shaft 28. Considering the direction of transmission of the reverse torque, the first torque limiter 261 is disposed downstream of the first power conversion unit 22A. Therefore, the reverse torque transmitted to the first torque limiter 261 is torque weakened by the first power conversion unit 22A. For example, the reverse torque is weakened to about one-fourth by the first power conversion unit 22A. For this reason, a small, inexpensive first torque limiter with a small threshold torque can be used as the first torque limiter 261.

[0073] 10 is a perspective view showing a second embodiment of the power transmission limiting unit 26. In this embodiment, only a second torque limiter 262 is mounted on the first vertical drive shaft 23A as the power transmission limiting unit 26. The other configurations are the same as those of the first embodiment. The configuration of the second torque limiter 262 is the same as that of the first torque limiter 261 described above.

[0074] By installing the second torque limiter 262 on the first vertical drive shaft 23A, the reverse torque transmitted to the first drive force transmission path 20A can be reduced. Specifically, in the reverse torque transmission path, the first vertical drive shaft 23A is disposed upstream of the first power conversion unit 22A. Therefore, the second torque limiter 262 reduces the reverse torque transmitted to the first power conversion unit 22A. This allows the first power conversion unit 22A to be small and inexpensive.

[0075] 11 is a perspective view showing a third embodiment of the power transmission limiting unit 26. In this embodiment, as the power transmission limiting unit 26, a first torque limiter 261 is attached to the horizontal drive shaft 28, and a second torque limiter 262 is attached to the first vertical drive shaft 23A.

[0076] The inclusion of the first torque limiter 261 and the second torque limiter 262 further reduces the counter torque acting on the engine 30. Specifically, if counter torque is generated by the first main rotor 12A coming into contact with an obstacle during flight, the counter torque is reduced by the second torque limiter 262 mounted on the first vertical drive shaft 23A. The counter torque is then transmitted to the first power conversion unit 22A. The counter torque is further reduced by the first torque limiter 261 mounted on the horizontal drive shaft 28, and then transmitted to the engine 30 via the coupling 27 and the first shaft 21A. The inclusion of the second torque limiter 262 allows a smaller first power conversion unit 22A to be employed. Furthermore, the inclusion of the first torque limiter 261 further effectively reduces the counter torque transmitted to the engine 30.

[0077] The above is a description of the structure and operation of the flight device 10 of this embodiment.

[0078] The main effects achieved by the above-described embodiment are as follows.

[0079] A flying device according to an embodiment of the present invention is a flying device that floats in the air and includes a rotor, a drive source, a driving force transmission path, and a power transmission limiter, wherein the rotor is configured to generate thrust by rotating, the drive source is configured to rotate the rotor by being drivingly connected to the rotor, the driving force transmission path is configured to transmit a rotational driving force from the drive source to the rotor, and the power transmission limiter is configured to limit the transmission of the rotational driving force in the driving force transmission path. According to the flying device of the present invention, by limiting the transmission of the rotational driving force, it is possible to prevent the rotational driving force acting on the driving force transmission path from becoming excessive.

[0080] In a flight device according to an embodiment of the present invention, the drive force transmission path includes a first power transmission unit, a power conversion unit, and a second power transmission unit. The first power transmission unit transmits the rotational drive force from the drive source to the power conversion unit. The power conversion unit converts the direction of the rotational drive force and transmits the rotational drive force to the second power transmission unit. The second power transmission unit transmits the rotational drive force to the rotor. The power transmission limiter is disposed in either the first power transmission unit or the second power transmission unit. According to the flight device of the present invention, the power transmission limiter is disposed in either the first power transmission unit or the second power transmission unit, thereby preventing excessive rotational drive force from acting on the first power transmission unit, the power conversion unit, or the second power transmission unit. However, the first power transmission unit, the power conversion unit, and the second power transmission unit are not necessarily required. For example, the flight device may include only the first power transmission unit.

[0081] In addition, in a flying device according to an embodiment of the present invention, the power conversion unit transmits the rotational driving force so that the rotational speed of the second power transmission unit is slower than the rotational speed of the first power transmission unit, and the power transmission limiting unit is disposed only on the first power transmission unit. According to the flying device of the present invention, the power conversion unit functions as a reducer, so that the torque acting on the first power transmission unit is smaller than the torque acting on the second power transmission unit. Therefore, a compact power transmission limiting unit can be used. Here, the power conversion unit may not reduce the rotational driving force, but may instead increase the speed of the rotational driving force or maintain the rotational driving force unchanged.

[0082] In addition, in a flying device according to an embodiment of the present invention, the power transmission limiting unit is disposed only in the second power transmission unit. With this flying device, even if torque acts from the rotor to the drive force transmission path due to contact or collision of the rotor, the transmission of that torque to the power conversion unit can be limited. Therefore, damage to the power conversion unit can be prevented when the rotor contacts or collides.

[0083] In a flying device according to an embodiment of the present invention, the power transmission limiting unit is disposed in the first power transmission unit and the second power transmission unit. According to the flying device of the present invention, even if torque acts on the drive force transmission path from the rotor due to contact or collision of the rotor, the torque transmitted to the drive source can be limited by the first power transmission unit and the second power transmission unit.

[0084] In a flight device according to an embodiment of the present invention, the drive source is an engine, and the flight device of the present invention can limit the torque acting on the engine.

[0085] In addition, in a flying device according to an embodiment of the present invention, the first power transmission unit extends substantially parallel, and the second power transmission unit extends substantially perpendicular. According to the flying device of the present invention, the rotor rotated by the second power transmission unit rotates around a vertically extending rotation axis. Therefore, there is a risk that the rotor may come into contact with an obstacle or the like during flight of the flying device. Even in such a case, the transmission of rotational driving force is limited by the power transmission limiting unit, thereby suppressing the transmission of torque from the rotor to the drive source.

[0086] In a flying device according to an embodiment of the present invention, the power transmission limiting unit is a torque limiter, which can effectively suppress the transmission of torque.

[0087] Although the embodiments of the present invention have been described above, the present invention is not limited to these and can be modified within the scope of the present invention. In addition, the above-described embodiments can be combined with each other.

[0088] Referring to FIG. 1, in this embodiment, the engine 30 is exemplified as the drive source, but a motor may also be used as the drive source.

[0089] Furthermore, devices other than torque limiters may be used as the power transmission limiting section, such as friction pads, clutches, or electromagnetic clutches.

[0090] REFERENCE SIGNS LIST 10 Flight device 11 Main body 12 Main rotor 12A First main rotor 12B Second main rotor 13 Sub rotor 13A First sub rotor 13B Second sub rotor 13C Third sub rotor 13D Fourth sub rotor 14 Motor 14A Motor 14B Motor 14C Motor 14D Motor 15 Support 17 Main arm 17A First main arm 17B Second main arm 18 Sub arm 18A Sub arm 18B Sub arm 18C Sub arm 18D Sub arm 20 Driving force transmission path 20A First driving force transmission path 20B Second driving force transmission path 21 Power transmission part 21A First shaft 21B Second shaft 22 Power conversion part 22A First power conversion part 22B Second power conversion part 23 Second power transmission portion 23A First vertical drive shaft 23B Second vertical drive shaft 24 Drive gear 25 Driven gear 26 Power transmission limiting portion 261 First torque limiter 262 Second torque limiter 27 Coupling 28 Horizontal drive shaft 29 Case 30 Engine 30A First opposing engine portion 30B Second opposing engine portion 31 Engine block 32 Cylinder chamber 33 First engine portion 331 First piston 332 First connecting rod 333 First crankshaft 34 Second engine portion 341 Second piston 342 Second connecting rod 343 Second crankshaft 35 First cylinder wall portion 36 Second cylinder wall portion 37 First extension wall portion 38 Second extension wall portion 39 Extension space 40 Combustion chamber

Claims

1. A flying device that floats in the air, comprising a rotor, a drive source, a drive force transmission path, and a power transmission limiting unit, wherein the rotor is configured to generate thrust by rotating, the drive source is configured to rotate the rotor by being drivingly connected to the rotor, the drive force transmission path is configured to transmit a rotational drive force from the drive source to the rotor, and the power transmission limiting unit is configured to limit the transmission of the rotational drive force in the drive force transmission path.

2. The flight device described in claim 1, characterized in that the driving force transmission path section comprises a first power transmission section, a power conversion section, and a second power transmission section, the first power transmission section transmits the rotational driving force from the driving source to the power conversion section, the power conversion section converts the direction of the rotational driving force and transmits the rotational driving force to the second power transmission section, the second power transmission section transmits the rotational driving force to the rotor, and the power transmission limiting section is arranged in the first power transmission section or the second power transmission section.

3. The flying device described in claim 2, characterized in that the power conversion unit transmits the rotational driving force so that the rotational speed of the second power transmission unit is slower than the rotational speed of the first power transmission unit, and the power transmission limiting unit is arranged only on the first power transmission unit.

4. The flight device according to claim 2, wherein the power transmission limiting section is disposed only in the second power transmission section.

5. A flight device as described in claim 2, characterized in that the power transmission limiting unit is disposed in the first power transmission unit and the second power transmission unit.

6. The flight device according to claim 1, wherein the driving source is an engine.

7. The flight device according to claim 2, wherein the first power transmission section extends substantially parallel, and the second power transmission section extends substantially perpendicular.

8. The flight device according to claim 1, wherein the power transmission limiting unit is a torque limiter.

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