KR102211475B1 - Aerial vehicle with distributed electric power tilt prop - Google Patents

Abstract

The present invention provides an aerial vehicle comprising: wings extending in both directions of a body; two or four tilt props tilted with respect to the body; and a control unit for controlling the tilt props. The tilt props (150) each include: a rotating shaft (151); a plurality of blades (152) extending in the radial direction of the rotating shaft; a shaft gear (153) provided at one end of the rotating shaft; a plurality of motor gears (155) rotating in engagement with the shaft gear; electric motors (156) respectively provided on the motor gears to transmit rotational force to the motor gears; and electronic speed controllers (158) respectively provided on the electric motors to adjust the speed of the electric motors. The aerial vehicle can minimize the number of propellers, power transmission shafts, and the like, which are mechanical parts with relatively high reliability, to two or four as in tilt rotor or quad tilt prop aerial vehicles, and can have multiple electric motors and multiple electronic speed controllers, which are power sources, thereby increasing safety. The aerial vehicle enables safe flight with only the remaining electric motors even if some of the electric motors malfunction, and can minimize the number of prop-rotors, thereby preventing the complexity of the machine and reducing weight.

Description

Aircraft with distributed electric power tilt prop{AERIAL VEHICLE WITH DISTRIBUTED ELECTRIC POWER TILT PROP}

The present invention relates to a distributed electric power transmission structure of a tilt rotor and tilt prop aircraft using electric power.

Tilt-rotor or tilt-prop aircraft are equipped with rotors to tilt the wings, so during take-off and landing, the rotors are arranged in a vertical direction to allow vertical take-off and landing of the aircraft. Flight is possible. The tiltrotor aircraft has a tandem rotor system in which rotors are installed on the left and right wings, and the rotors rotate in opposite directions. Unlike a single rotor helicopter in which one rotor is installed in the center of the fuselage, the tandem rotor type aircraft does not require a tail rotor because the torques of the left and right rotors cancel each other, and the attitude control method of the aircraft is also different from each other.

In general, a tiltrotor aircraft has the function of adjusting the pitch of the rotor blades and is capable of vertical take-off and landing, hovering in place (hovering), which is the motion to stop after vertical take-off, low-speed flight in rotary wing mode, and high-speed flight in fixed wing mode.

Recently, the development of new concept aircraft for future autonomous personal aircraft (PAV) or air taxi (Air Taxi) is being actively developed worldwide, and as part of this, an electric propulsion aircraft shape using electric power has been proposed (Fig. 1 or Fig. 1). 2).

However, the conventional electric propulsion vehicle is equipped with at least six propellers on the vehicle, and each propeller is composed of a set of propellers that generate thrust or lift and an electric motor that provides power. When a rotor is installed, it is common to have the same number of propellers and electric motors.

Such a conventional electric propulsion vehicle should be able to maintain the attitude of the aircraft and fly by using the remaining normally operating prop rotors when failure or damage occurs in one of the prop rotors. A flight control algorithm has to be developed and technically verified to be safe to ensure that there are as many cases as the number of rotor failures or damage can occur as the number of prop-rotors, and to maintain a normal attitude and fly as much as in all cases. In order to satisfy the degree of safety required for airworthiness certification, reliability must be as high as the number of propellers, and it is difficult to secure such safety, airworthiness certification, and flight reliability.

An object of the present invention is to provide a technology to increase safety by multiplexing electric motors and electronic speed controllers that are relatively weak in stability compared to mechanical parts in an aircraft equipped with a plurality of tilt props, and specifically, some electric motors are broken. Even when this occurs, the purpose of providing a technology that prevents the complexity of the aircraft structure and reduces weight while allowing safe flight with only the remaining electric motors.

That is, the present invention applies a plurality of electric motors to each prop rotor in a tilt rotor and tilt prop aircraft using electric power, and even if a failure or abnormality occurs in one electric motor, it is generated in the prop rotor using the power of the remaining electric motors. Its main purpose is to improve flight safety by allowing the vehicle to land safely with the lift and control power.

The present invention is an aircraft comprising a wing extending in both directions of the body, two or four tilt props tilted with respect to the body, and a control unit for controlling the tilt prop, the tilt prop 150, A rotating shaft 151; A plurality of blades 152 extending in the radial direction of the rotating shaft; A shaft gear 153 provided at one end of the rotating shaft; A plurality of motor gears 155 engaged with the shaft gears and rotated; An electric motor 156 provided in each of the motor gears to transmit rotational force to the motor gears; And an electronic speed controller 158 provided in each of the electric motors to adjust the speed of the electric motor. It provides an aircraft having a distributed electric power tilt prop.

If any one of the plurality of electric motors fails, the control unit rotates only the remaining normally operating electric motors and transmits the rotational force to the rotating shaft, and the power required for rotating the rotating shaft is transferred to the normal operating electric motor. Evenly distributed and handled, the shaft of the failed electric motor is controlled to freely rotate with the rotating shaft.

A motor shaft 157 for transmitting the rotational force of the electric motor to the motor gear; And a one-way clutch bearing provided between the motor shaft and the motor gear to transmit rotational force in only one direction, and preventing back electromotive force from being generated by rotation of the failed motor shaft.

The number of motor gears meshed with the shaft gear 153 may be at least two, and preferably four or six motor gears are preferably arranged.

The present invention minimizes the number of propellers and power transmission shafts, which are mechanical parts with relatively high reliability, to two or four, such as a tiltrotor or quad-tilt prop aircraft, and multiplexes electric motors and electronic speed controllers as power sources. As a result, safety is enhanced, and even if a part of the electric motor malfunctions, safe flight is possible with only the remaining electric motors, and the number of prolotors is minimized to prevent the complexity of mechanical devices and to reduce weight. .

1 and 2 are views of the electric propulsion vehicle according to the prior art,
3 and 4 are conceptual diagrams of an aircraft having a distributed electric power tilt prop according to an embodiment of the present invention,
5 is a perspective view of a distributed electric power tilt prop according to an embodiment of the present invention,
6 is a perspective view of a reduction device using a belt applied in the prior art in order to increase the efficiency of the electric motor because the maximum output rotation speed of the electric motor (RPM) is higher than the optimum rotation speed of the prol
7 and 8 are partial views of the internal structure of the distributed electric power tilt prop according to the present invention, and FIG. 7 shows the four motors share the required power of the prop rotor during normal operation by 1/4, and FIG. 8 shows one motor. In the event of a failure, the remaining three motors that operate normally share the required power of the prop rotor by 1/3.

Objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. In addition, the terms used are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user operator. Therefore, definitions of these terms should be made based on the contents of the present specification.

3 and 4 are conceptual diagrams of an aircraft having a distributed electric power tilt prop according to an embodiment of the present invention, and FIG. 5 is a perspective view of a distributed electric power tilt prop according to an embodiment of the present invention, and FIGS. 7 to 8 is a partial view of the internal structure of a distributed electric power tilt prop according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the drawings.

Electric propulsion aircraft uses electric power as a power source to obtain rotational force from an electric motor and use it as propeller rotational force to obtain flight propulsion. In general, propellers, which are mechanical components, have relatively high reliability, and electric motors or electronic speed control (ESC) are the main targets for safety improvement in electric propulsion vehicles. The present invention reflects this and minimizes two or four propellers and power transmission shafts, which are mechanical parts with relatively high reliability, as shown in Figs. 3 to 4, and increases safety by multiplexing electric motors and electronic speed controllers as power sources. It is a feature. In general, as shown in FIG. 6, the maximum output rotational speed (RPM) of the motor is greater than the optimum rotational speed of the prop, so to increase the efficiency of the motor, a belt for reduction or a gear for reduction is used. There is no need for a separate reduction device by arranging a large number of small diameter motor gears around the connected gears.

Through this, the multidistributed electric propulsion vehicle presented as a universal vehicle shape of a personal aircraft or air taxi is equipped with a number of propulsion devices (proprotor + electric device), so that even if one propulsion device fails during flight, it is stable. It satisfies the fundamental purpose of making this possible, while minimizing the increase in the number of propellers, thereby preventing the complexity of the machine and reducing the weight.

In general, since the flight efficiency of a vertical take-off and landing aircraft is improved as the diameter of the propeller is relatively large, it is possible to improve the flight efficiency by reducing the number of prop rotors and increasing the prop rotor diameter for a vehicle of the same weight. Using a simple momentum theory, the equations of power loading (PL), which represents the ratio of the generated thrust to the prop-rotor consumption power required for in-situ flight, and disk loading (DL), which represents the ratio of the thrust to the prop-rotor area, are expressed as follows. .

When the vertical take-off and landing aircraft fly in place, the total thrust of the prop rotor required is the same as the total weight of the aircraft, and as the number of props increases, the DL relatively increases, so that the PL indicating flight efficiency (performance) decreases. For reference, when the PL is large, the required power is reduced for the same weight of the vehicle, that is, the required thrust, and this decreases the fuel consumption rate. With this principle, when the weight of the vehicle is the same, the number of propellers is minimized, and the flight efficiency (performance) is maximized when the diameter of the propeller is maximized within several design limits.

In the present invention, the number of propellers is reduced compared to the conventional multi-dispersion propulsion system, so that the total number of parts is reduced, and on the contrary, maintainability and safety are improved, and as a result, a lot of work required to match uniformity of individual blades and propellers (track & Balancing, pitch angle correction, etc.) It has the advantage of significantly reducing the time required for inspection before and after flight.

4 to 5, the present invention includes a blade 120 extending in both directions of the body together with the body 110, two or four tilt props 150 tilted with respect to the body, and the It includes a blade 152 provided in the tilt prop and rotates, and a control unit for controlling the tilt prop.

The tilt prop 150 includes a rotation shaft 151, a plurality of blades 152 extending in a radial direction of the rotation shaft, a shaft gear 153 provided at one end of the rotation shaft, and the shaft gear A plurality of motor gears 155 engaged with and rotating, an electric motor 156 provided in each of the motor gears to transmit rotational force to the motor gears, and an electron provided in each of the electric motors to control the speed of the electric motor It includes a speed controller 158.

When the electric motor 156 rotates by receiving power from a battery provided in the aircraft of the present invention, the rotational force of the motor is transmitted to the rotational shaft through gears meshed with the blade 152 to generate lift and propulsion.

In general, the maximum output rotational speed (RPM) of the electric motor is higher than the optimum rotational speed of the rotating shaft. As shown in Fig. 6, in order to increase the efficiency of the electric motor, the motor shaft 157 includes a first shaft 157a and a second shaft 157b, and a deceleration belt B ) Was mainly applied to the prior art. However, a gear for reduction may be provided instead of a belt for reduction. In the present invention, as shown in Figs. 7 to 8, a plurality of motor gears meshed with the shaft gear 153 are disposed at least two or more.

The control unit of the flight vehicle according to the present invention, when any one of the plurality of electric motors 156 (156-1 in Fig. 8) fails, rotates only the remaining normal operating electric motor to rotate the shaft ( 151). In addition, the control unit distributes the power required for rotation of the rotation shaft 151 equally to the electric motors operating normally, and the shaft of the failed electric motor 156-1 is free together with the rotation shaft. Control to rotate.

Even if one of the electric motors fails, since the rotation shaft 151 is engaged with the gears, it is preferable that the rotational force is transmitted from the rotational shaft to the failed electric motor so that back electromotive force does not occur in the electric motor. To this end, it is provided between the motor shaft 157 and the motor gear 155 that transmits the rotational force of the electric motor to the motor gear, and transmits the rotational force only in one direction (from the electric motor to the motor gear). By providing a clutch bearing, back electromotive force is prevented from being generated by rotation of the failed motor shaft.

In the present invention, when the multi-electric motor method is applied, a desired deceleration is possible by appropriately adjusting the proprotor shaft and the motor shaft gear diameter, so that an additional device for reducing the rotational speed is not required, and one motor is broken as shown in FIG. Even if it does, the remaining three motors distribute and handle the power evenly, and the failed motor shaft rotates freely like the shaft of the propeller, that is, the shaft shaft 151. 'Ppop' shown in FIGS. 7 and 8 means the required (necessary) horsepower of the prop rotor required for normal flight.

In the figure, the number of electric motors is shown as four, but the number of motors is not limited to four, and a desired optimal number combination is possible. In other words, the size of the motor increases in proportion to the maximum horsepower of the motor, and the optimal number combination is possible from two or more motors to the maximum number of mounting spaces allowed, and the maximum horsepower of an individual electric motor By selecting the motor so that the value multiplied by the number is more than the maximum power required by the prop rotor, even if one motor fails, the remaining motors can provide the required horsepower required for flight, and a safe flight or return to a safe place is possible. Is done.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims are also present. It belongs to the scope of rights of

Claims (4)

An aircraft comprising wings extending in both directions of the body, two or four tilt props tilted with respect to the body, and a control unit for controlling the tilt prop,
The tilt prop 150,
Rotating shaft 151; A plurality of blades 152 extending in the radial direction of the rotating shaft; A shaft gear 153 provided at one end of the rotating shaft; A plurality of motor gears 155 engaged with the shaft gears to rotate; An electric motor 156 provided in each of the motor gears to transmit rotational force to the motor gears; And an electronic speed controller 158 provided in each of the electric motors to adjust the speed of the electric motor.
The control unit,
When any one of the plurality of electric motors fails, only the remaining normal operating electric motors are rotated to transmit rotational force to the rotating shaft,
Distributed electric power tilt prop, characterized in that the power required for rotation of the rotating shaft is equally distributed to the electric motor operating normally, and the shaft of the failed electric motor is controlled to freely rotate together with the rotating shaft. One aircraft. delete The method of claim 1,
A motor shaft 157 for transmitting the rotational force of the electric motor to the motor gear; And a one-way clutch bearing provided between the motor shaft and the motor gear to transmit rotational force only in one direction,
An aircraft having a distributed electric power tilt prop, characterized in that the back electromotive force is not generated by rotation of a broken motor shaft. The method of claim 1,
An aircraft having a distributed electric power tilt prop, characterized in that a plurality of motor gears meshed with the shaft gear 153 are provided.

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