Technical Field

[1] The present invention relates, in general, to vertical take-off and landing (VTOL) aircrafts and, more particularly, to a VTOL aircraft, which has two or more rotary units, so that the reaction torques of the rotary units can balance each other, thus being offset without requiring a separate balancing device, and which has a casing to cover the rotary units, so that the blades of the rotary units rotate in the casing, thus preventing the generation of unbalanced lift on the rotating blades, unlike conventional helicopters, when the VTOL aircraft flies forwards, and which has a protective unit in the casing, thus preventing the rotating blades from inflicting bodily injury on a person, from causing damage to articles outside the casing, and from being broken by foreign obstacles, with a rudder provided in at least one of the openings of the casing, so that the VTOL aircraft can freely yaw or fly forwards and backwards, and which has remarkably improved flying performance if an accelerator for the yawing motion or the forward and backward flying motion is provided in the VTOL aircraft.

[2]

Background Art

[3] FlG. 1 is a perspective view illustrating a conventional vertical take-off and landing

(VTOL) aircraft 1. As shown in FlG. 1, the conventional VTOL aircraft 1 comprises a body 20, a plurality of support shafts 10 extending from the body 20, and a rotary unit

30 provided on an end of each of the support shafts 10. The rotary unit 30 comprises a motor 31, which is securely mounted in the rotary unit 30 and produces a rotating force. The rotary unit 30 further includes a blade 37 which is connected to the motor

31 through a pinion gear 33 and a spur gear 35, so that, when the motor 31 is rotated, the blade 37 is rotated. Due to the rotation of the blade 37, lift is generated on the rotating blade 37, thus enabling the VTOL aircraft 1 to fly. The body 20 comprises an upper cover 21, a device unit 22 and a lower cover 23. The device unit 22 includes several devices, for example, a signal transceiver. The body further includes a battery 25 to electrically activate the motor 31. The device unit 22 and the battery 25 are placed in a chamber which is defined between the upper and lower covers 21 and 23. In FlG. 1, reference numeral 36a denotes a blade locking screw, 36b denotes a gear locking screw, and 36c denotes a motor locking screw.

[4] FlG. 2 illustrates the conventional VTOL aircraft 1 when the aircraft 1 flies forwards in a direction 'C with the blade 37 rotating in a direction 'B'. In FlG. 2, the reference character ¹ V denotes the relative velocity of air. As shown in FlG. 2, when

the conventional VTOL aircraft 1 flies forwards in the direction ¹ C with the blade 37 rotating in the direction 'B', the velocity of air relative to the part ® of the rotating blade 37 becomes higher than the velocity of air relative to the part ⁽ D of the rotating blade 37. Thus, lift on the rotating blade 37 at the part ® becomes higher than that at the part ©, thereby causing unbalanced lift on the rotary unit 30.

[5] As described above, in the conventional VTOL aircraft, the rapidly rotating blade

37 is exposed outside, so that, when the blade 37 undesirably collides with an outside article during flight of the VTOL aircraft, the blade 37 may cause severe damage to the outside article and, furthermore, may be broken by the outside article. Furthermore, as shown in FIG. 2, due to a difference in the velocity of air relative to the rotating blade 37 between parts of the blade 37, unbalanced lift is generated on the rotary unit 30. The blades 37 of the plurality of rotary units 30 are rotated by respective motors 31, so that a plurality of motors 31, the number of which corresponds to the number of blades 37, must be provided. Furthermore, because the blades 37 of the rotary units 30 are rotated by respective motors 31, reaction torques may be generated on the rotary units 30 if the motors 31 are rotated differently. In the above state, the flying stability of the VTOL aircraft may be reduced. When the conventional VTOL aircraft 1 is overturned during flight, the aircraft cannot fly normally, but may crash. Furthermore, in the case of a unmanned aircraft or a radio-controlled aircraft, which requires a user to directly handle the exposed propellers or blades, the exposed and rapidly rotating blade is very dangerous in that the blade may cause a serious accident and/or may inflict bodily injury on a person.

Disclosure of Invention Technical Problem

[6] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a vertical take-off and landing (VTOL) aircraft, in which the reaction torques of rotary units can balance each other, thus being offset, and which has a casing to cover the rotating blades, thus preventing the generation of unbalanced lift on the rotating blades when the VTOL aircraft flies forwards, and in which, because the rotating blades are covered by the casing, the blades are prevented from colliding with outside articles, thus being protected from the articles, and which prevents the rotating blades from colliding with the body of a person, thus having improved safety to allow a user to directly hold the casing with his/her hands during use of the aircraft, and in which the casing has a streamlined shape to reduce air resistance, and in which the casing is formed into a predetermined duct shape or is provided with a sidewall in each opening thereof, thus increasing the thrust to propel the aircraft by about 10 ~ 15%, and which

transmits a rotating force from one drive gear to the blades through two or more driven gears, thus flying using a single drive unit, and in which the blades are constructed to rotate in opposite directions, thus not generating reaction torques or requiring yaw control during the takeoff or landing of the aircraft, and in which the blades have a pitch control means, so that, even if the VTOL aircraft is undesirably overturned during flight, the aircraft can easily restore its original state, and which allows a user to fly the aircraft normally or execute stunt flying using the aircraft while independently or concurrently controlling the pitches of the blades, and which has a rudder to enable the aircraft to fly perfectly horizontally or to safely hover.

[7]

Technical Solution

[8] In order to accomplish the above object, the present invention provides a vertical take-off and landing (VTOL) aircraft, comprising a body, two or more rotary units, which are coupled to the body and which each comprise a rotating shaft and a blade, and a casing, which covers both the body and the rotary units and is provided with a plurality of openings.

[9] In the VTOL aircraft, the casing may be formed into a duct shape with each of the openings defined in the duct-shaped casing to receive each of the rotary units therein.

[10] In the VTOL aircraft, the casing is preferably provided with a sidewall to surround the blade of each of the rotary units, and the sidewall provided in the casing is preferably constructed to be tiltable.

[11] Each of the openings of the casing is preferably provided with a protective means to prevent the blade from coming into contact with outside articles, and at least one of the openings of the casing is preferably provided with a rudder.

[12] Furthermore, the VTOL aircraft preferably further comprises a drive gear, driven gears, the number of which corresponds to the number of rotary units and which engage with the drive gear, and a power transmission means to transmit a rotating force of the driven gears to the rotating shaft of each of the rotary units.

[13] The VTOL aircraft preferably further comprises an accelerator for rotating motion or forward and backward flying motion.

[14] Each of the rotary units preferably comprises the rotating shaft having a horizontal shaft, a blade holder rotatably mounted to the horizontal shaft, a pitch plate provided on the rotating shaft to reciprocate, a pitch link rotatably coupled to both the pitch plate and the blade holder, and a pitch lever rotatably coupled to a support shaft and having a first end coupled to the pitch plate and a second end coupled to a pitch adjusting bar, so that the blades of the rotary units can execute a pitching function.

[15]

Advantageous Effects

[16] The above-mentioned VTOL aircraft 100 according to the present invention comprises two or more rotary units 130, so that the reaction torques of the rotary units 130 can balance each other, thus being offset without requiring a separate balancing device. The VTOL aircraft further comprises a casing 201 to cover the blades 135 of the rotary units 130, so that the blades 135 rotate in the casing 201, thus preventing the generation of unbalanced lift on the rotating blades 135, unlike conventional helicopters, when the VTOL aircraft flies. Furthermore, the rotary units 130 are prevented from coming into contact with outside articles, so that it is possible to prevent breakage of the rotary units 130 and damage to outside articles. Due to a structural feature of the casing 201, the thrust to propel the VTOL aircraft can be increased by about 10 ~ 15%. Furthermore, a rudder 301 is provided in the casing 201, so that the VTOL aircraft can freely yaw or fly forwards and backwards according to the orientation of the rudder 301. The casing 201 may have a streamlined shape to reduce air resistance, and may have an accelerator 400 for rotating motion or forward and backward flying motion, thus remarkably improving the flying performance of the VTOL aircraft. Furthermore, the rotary units 130 are provided with respective pitching means, so that a user can fly the VTOL aircraft normally or execute highly skilled stunt flying using the aircraft. In addition, even if the VTOL aircraft 100 is undesirably overturned during flight, the aircraft can fly normally in the overturned state. Brief Description of the Drawings

[17] FIG. 1 is a perspective view illustrating a conventional vertical take-off and landing

(VTOL) aircraft;

[ 18] FIG. 2 is an enlarged plan view of the portion 'A' of FIG. 1 ;

[19] FIG. 3 is a perspective view illustrating a VTOL aircraft according to a preferred embodiment of the present invention;

[20] FIG. 4 is an exploded perspective view of the VTOL aircraft of FIG. 3 ;

[21] FIG. 5 is a perspective view illustrating a casing of the VTOL aircraft according to the preferred embodiment of the present invention;

[22] FIG. 6 is a perspective view illustrating a body and a plurality of rotary units of the

VTOL aircraft according to the preferred embodiment of the present invention;

[23] FIG. 7 is an enlarged perspective view illustrating parallel arrangement of a rudder relative to the support shaft of the rotary unit of FIG. 6;

[24] FIG. 8 is an enlarged perspective view illustrating a rotary unit and a rudder according to a modification of the embodiment of FIG. 7, in which the rudder is placed at different angles to cross the support shaft of the rotary unit;

[25] FIG. 9 is a perspective view illustrating an example of a power transmission

mechanism provided in the VTOL aircraft according to the preferred embodiment of the present invention;

[26] FlG. 10 is an enlarged perspective view illustrating the rotary unit of the VTOL aircraft according to the preferred embodiment of the present invention;

[27] FlG. 11 is a perspective view illustrating a VTOL aircraft according to another preferred embodiment of the present invention;

[28] FlG. 12 is a perspective view illustrating a VTOL aircraft, which comprises a casing that does not have any sidewall, according to yet another preferred embodiment of the present invention; and

[29] FlG. 13 is a partially broken perspective view illustrating a VTOL aircraft, which comprises a rotary unit having upper and lower blades, according to still another preferred embodiment of the present invention. Best Mode for Carrying Out the Invention

[30] Herein below, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[31] FlG. 3 is a perspective view schematically illustrating a VTOL aircraft 100 according to a preferred embodiment of the present invention. FlG. 4 is an exploded perspective view of the VTOL aircraft 100 of FlG. 3. FlG. 5 is a perspective view illustrating a casing 201 of the VTOL aircraft according to the preferred embodiment of the present invention. FlG. 6 is a perspective view illustrating a body 120 and a plurality of rotary units 130 of the VTOL aircraft 100 according to the preferred embodiment of the present invention. FIGS. 7 and 8 are enlarged perspective views each illustrating one of the rotary units 130 and a rudder 301. FIG. 9 is a perspective view illustrating an example of a power transmission mechanism provided in the VTOL aircraft 100 according to the preferred embodiment of the present invention. FlG. 10 is an enlarged perspective view illustrating the rotary unit 130. FlG. 11 is a perspective view illustrating a VTOL aircraft 100 according to another preferred embodiment of the present invention. FlG. 12 is a perspective view illustrating a VTOL aircraft 100, which comprises a casing 201 that does not have any sidewall, according to yet another preferred embodiment of the present invention. FlG. 13 is a partially broken perspective view illustrating a VTOL aircraft 100, which comprises a rotary unit 130 having upper and lower blades, according to still another preferred embodiment of the present invention.

[32] As shown in FIGS. 3 through 6, the vertical take-off and landing (VTOL) aircraft

100 according to a preferred embodiment of the present invention comprises a body 120, two or more rotary units 130 which are coupled to the body 120 and each comprise a rotating shaft 131 and a blade 135, and a casing 201 which covers the body

120 and the rotary units 130 and is provided with a plurality of openings 201a. The casing 201, which has the openings 201a, is preferably provided with a side wall 203 in each of the openings 201a such that the sidewall 203 surrounds the blade 135 of the rotary unit 130. Because the casing 201 is provided with one sidewall 203 around the blade 135 in each of the openings 201a as described above, the blade 135 stably rotates as though it were rotating within a duct, thus increasing the thrust to propel the aircraft by about 10 ~ 15%. In FlG. 5, the reference numeral 203a denotes a hole which is formed in the sidewall 203 so as to allow the rotary unit 130 to be placed and operated in the opening 201a.

[33] As shown in FlG. 11, a VTOL aircraft 100 according to another preferred embodiment of the present invention may comprise a plurality of casings 201 which may be formed into a predetermined duct shape, with an opening 201a defined in each casing 201 to surround a rotary unit 130. In FIG. 11, the reference numeral 205 denotes a reinforcing rib which connects the casings 201 to each other.

[34] In the present invention, the sidewall 203 shown in FIGS. 3, 4 and 5 or the casing

201 shown in FlG. 11 is preferably constructed to be tiltable, so that the VTOL aircraft 100 can freely yaw or fly forwards and backwards.

[35] As shown in FIGS. 3, 4 and 11, each of the openings 201a of the casing 201 is preferably provided with a protective means 207 to prevent the blade 135 from coming into contact with outside articles. The protective means 207 may be selected from a net or a door.

[36] As shown in FlG. 6, the body 120 of the VTOL aircraft 100 according to the preferred embodiment of the present invention includes a drive unit 125 and a plurality of support shafts 110 extending from the body 120, with a rotary unit 130 provided at the end of each of the support shafts 110. However, it should be understood that the construction of the body 120 is not limited to the above-mentioned construction, but may be altered such that the rotary units 130 are directly mounted to the body 120 without having such support shafts 110, as in a conventional helicopter, without affecting the functioning of the present invention. In the preferred embodiment of FlG. 6, the drive unit 125 comprises an engine 125a and a fuel storage tank 125b, but it should be understood that the drive unit 125 may comprise a motor and a battery.

[37] As shown in FIGS. 3, 4, 6, 7 and 8, the VTOL aircraft 100 according to the preferred embodiment of the present invention further comprises a rudder 301 which is provided in at least one of the openings 201a of the casing 201. In FIGS. 6 through 8, the reference numeral 301a denotes a rotating shaft of the rudder 301. FlG. 7 illustrates the rudder 301 which is placed in parallel to the support shaft 110, while FlG. 8 illustrates the rudder 301 which is placed to cross the support shaft 110. When the rudder 301 is placed as shown in FlG. 7, the VTOL aircraft 100 can yaw using the

rudder 301. Furthermore, when the rudder 301 is placed as shown in FIG. 8, the VTOL aircraft 100 can fly forwards and backwards using the rudder 301.

[38] As illustrated in FIGS. 4, 6, 9 and 11, the VTOL aircraft 100 according to the preferred embodiment of the present invention further comprises a drive gear 121, which is coupled to the drive unit 125 of the body 120 and rotates along with the drive unit 125, a plurality of driven gears 123, the number of which corresponds to the number of rotary units 130 and which engages with the drive gear 121, and a power transmission means 126 to transmit a rotating force of the driven gears 123 to the rotating shaft 131 of each of the rotary units 130. As shown in FIG. 9, the power transmission means 126 according to the preferred embodiment of the present invention comprises a first pulley 126a integrally formed with each of the driven gears 123, a second pulley 126b provided around the rotating shaft 131 of each of the rotary units 130, and a transmission belt 126c wrapped around the two pulleys 126a and 126b and transmitting the rotating force from the first pulley 126a to the second pulley 126b. Alternatively, the power transmission means 126 may be realized such that one drive unit 125 is provided to each rotary unit 130, so that the blades 135 can be driven by respective drive units 125.

[39] As shown in FIGS. 4 and 12, the VTOL aircraft 100 according to another preferred embodiment of the present invention may further comprise an accelerator 400, which is provided in the casing 201 to rotate or fly forwards and backwards. In the above state, the VTOL aircraft 100 can freely yaw or fly forwards and backwards.

[40] As illustrated in FTG. 10, in the VTOL aircraft 100 according to another preferred embodiment of the present invention, each of the rotary units 130 preferably comprises a rotating shaft 131 which has a horizontal shaft 131a, a blade holder 133 which is rotatably mounted to the horizontal shaft 131a, a pitch plate 148 which is provided on the rotating shaft 131 to reciprocate, a pitch link 149 which is rotatably coupled to both the pitch plate 148 and the blade holder 133, and a pitch lever 145 which is rotatably coupled to a support shaft 110 and has a first end coupled to the pitch plate 148 and a second end coupled to a pitch adjusting bar 129. Thus, the blades 135 of the rotary units 130 can execute a pitching function. Therefore, even if the VTOL aircraft 100 is undesirably overturned during flight, the aircraft can fly normally due to the pitching function of the blades 135 in the overturned state. Furthermore, the user can fly the aircraft normally or execute highly skilled stunt flying using the aircraft while actively controlling the pitches of the blades 135 of the rotary units 130, either independently or concurrently. Though a kind of pitch control means is presented in fig 10, the scope of the present invention is not limited the pitch control means in fig 10 and it is possible to adapt various kinds of pitch control means.

[41] As shown in FIG. 12, the VTOL aircraft 100 may comprise a casing 201, which

does not have any sidewall, according to yet another preferred embodiment of the present invention. Furthermore, as shown in FIG. 13, the VTOL aircraft 100 according to still another preferred embodiment of the present invention may comprise a rotary unit 130 which has upper and lower blades rotating in opposite directions. In the embodiment shown in FIG. 13, the rotary unit 130 comprises upper and lower blades 135 having the same size. However, it should be understood that the rotary unit 130 may comprise upper and lower blades 135 having different sizes.

[42] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

[43]