Helicopter with coaxial rotor structure, where the rotation of the rotors is driven by a differential gearbox

Abstract

Designing helicopters with vertical take-off and landing capability to have a coaxial dual- rotor structure. Preventing the rotational force around its own axis that would occur in the helicopter body by using a differential gearbox system in the drive system of the rotors, performing the horizontal right-left turning movement of the helicopter body by changing the torque applied to the rotors with an electric generator-motor. Providing the horizontal balance of the helicopter with a side motor-propeller group that will be placed on the sides of the helicopter and provides vertical lifting force. Enabling the helicopter body to be made symmetrically by removing the tail system and making the helicopter more compact and dynamic.

Description

[0001] HELICOPTER WITH COAXIAL ROTOR STRUCTURE, WHERE THE ROTATION OF THE ROTORS IS DRIVEN BY A DIFFERENTIAL GEARBOX

[0002] Technical Field

[0003] Innovation to be brought to helicopters with vertical take-off and landing capability. The compact and dynamic structure advantages that this innovation will bring to helicopters.

[0004] State-of-the-Art

[0005] In helicopters with vertical take-off and landing capability, while a rotational force is applied to the rotors that provide the upward lifting force of the vehicle, the helicopter's body is subjected to a force in the opposite direction of the rotational force applied to the rotors.

[0006] The reverse rotational force experienced by the helicopter's body must be eliminated, balanced, and controlled.

[0007] This force is balanced using different methods in vertical take-off and landing aircraft:

[0008] In single-rotor helicopters, it is balanced by the tail rotor.

[0009] In tandem dual-rotor helicopters, this balance is achieved with two separate rotors rotating in opposite directions.

[0010] In helicopters with a coaxial rotor structure, this balance is achieved with two superimposed rotors rotating in opposite directions, canceling each other's axial force. In electric-powered drones, this balance is also achieved by applying different speeds to rotors rotating in opposite directions.

[0011] In helicopters with vertical take-off and landing capability, horizontal balance is achieved by changing the angular positions of the rotor blades at different rotation angles while the helicopter's vertical lift-generating rotors rotate 360 degrees. The mechanism that changes the angles of the rotor blades is called the Swashplate.

[0012] In drones, horizontal balance is achieved by creating a difference between the speeds of some of the rotors that provide vertical lift.

[0013] Details to the State-of-the-Art

[0014] The system currently in use is the single-rotor classic helicopter (Figure 1):

[0015] The lifting force of the helicopter is provided by a single rotor (10) driven by the engine. While the single rotor (10) driven by the engines applies a vertical lifting force to the helicopter, it creates a rotational force on the helicopter body (1) in the opposite direction of the rotor's rotation. To eliminate this rotational force, a counter force sufficient to cancel the rotation is applied to the helicopter body (1) with a tail rotor (15). Overcoming one force with another force causes energy loss. By changing the speed of the tail rotor (15), the rotational force applied to the helicopter body (1) is increased or decreased, allowing the helicopter to turn horizontally to the right or left. The balance of the single-rotor classic helicopter (Figure 1) with respect to the horizontal plane (horizontal balance) is provided by the swashplate mechanism (14). The swashplate mechanism (14), as seen in Figure 8, changes the blade pitch angle (12) of the rotor blades (11) relative to the horizontal axis, thus: a. Changing the vertical lifting force of the single rotor (10). b. As seen in Figure 7, while the single rotor (10) rotates in the single rotor rotation direction (19), the horizontal balance of the helicopter is provided or the horizontal balance is intentionally disrupted by changing the blade pitch angle (12) at different rotation angles. An example of disrupting the horizontal balance of the helicopter: raising the front part of the helicopter, tilting it to the right or left at the desired angle. As seen in Figure 7, if the blade pitch angle (12) is increased at a rotation angle of 0° of the single rotor (10), the front part of the helicopter body (1.1) rises. Since the swashplate mechanism (14) continuously changes the blade pitch angle (12) at different angular values of the single rotor (10) rotation angle (Figure 7), the rotation speed of the single rotor (10) cannot be brought to the desired levels. That is, the rotation speed of the single rotor (10) is low. This increases the diameter of the single rotor (10). Because the diameter of the single rotor (10) is large, the helicopter needs a wider runway. These are the disadvantages of the single-rotor classic helicopters currently in use.

[0016] The system currently in use is the coaxial rotor helicopter (Figure 2):

[0017] The lifting force of the helicopter is provided by two rotors, a lower rotor (8) and an upper rotor (9), driven by engines. The rotors, rotating in the lower rotor rotation direction (20) and upper rotor rotation direction (21) (in opposite directions to each other), do not create a rotational force on the helicopter body (1). This provides energy savings. However, in this structure, two swashplate mechanisms are used: a lower rotor swashplate mechanism (14.1) to adjust the blade pitch angle (12) of the lower rotor (8) and an upper rotor swashplate mechanism (14.2) to adjust the blade pitch angle (12) of the upper rotor (9). In this system, the horizontal balance of the helicopter is achieved by changing the blade pitch angle (12) at different rotation angles of the rotors, as in Figure 7, for both rotors. Horizontal turning of the helicopter to the right or left is achieved by:

[0018] Changing the blade pitch angle (12) of the upper rotor (9) and / or the lower rotor (8) at different ratios, creating a rotational force on the helicopter body (1).

[0019] Utilizing the airflow created from top to bottom by the upper rotor (9) and the lower rotor (8), and cutting the downward airflow at different angles with the tail flaps (16).

[0020] The system currently in use, the coaxial rotor helicopter (Figure 2), uses a double swashplate mechanism, which causes manufacturing difficulties and complexity, and each mechanism requires maintenance and has a risk of failure. Since the lower rotor swashplate mechanism (14.1) continuously changes the angle of the lower rotor (8) and the upper rotor swashplate mechanism (14.2) continuously changes the angle of the upper rotor (9) at certain parts of the rotor rotation angles, the speeds of the lower rotor (8) and the upper rotor (9) cannot be increased to the desired level. That is, the rotation speed of the rotors is low. This increases the diameter of the rotors. Because the diameters of the rotors are large, the helicopter needs a wider runway. These are the disadvantages of the coaxial rotor helicopters currently in use.

[0021] Purpose and Objectives of the Invention

[0022] In helicopters with vertical take-off and landing capabilities; a. By using a coaxial rotor structure with 2 rotors rotating on top of each other and in opposite directions, and by driving the rotational movement of these rotors with a differential gearbox, the rotational force that would occur in the helicopter body will be eliminated, thus providing energy savings. b. Since the power transferred to the rotors in the differential gearbox will be changed electronically, the horizontal turning movement of the helicopter to the right and left will become easier and more dynamic. c. With the Swashplate mechanism, the need to change the angular positions of the rotor blades at different rotation angles while the rotors providing the lifting force of the helicopter rotate 360 degrees will be eliminated, thus allowing the rotors to rotate faster and reducing the rotor diameters. d. Due to the reduction in rotor diameter, it will be able to take off and land from a smaller area. e. Since horizontal position balance will be provided by balance motors and rotors added to the sides of the helicopter, the horizontal balance of the helicopter will become more dynamic. f. Since the helicopter body will be suitable for being made symmetrically, side winds will affect the front and rear parts of the helicopter body equally. g. Since the helicopter body will be suitable for being made symmetrically, the internal volume of the helicopter will expand. h. Since the internal volume of the helicopter will increase, there will be the possibility of carrying more cargo and / or people. i. Since the helicopter body will be suitable for being made symmetrically, there will be the possibility of accommodating two separate pilots (an important factor in rescue and combat environments).

[0023] Brief Description of the Invention

[0024] Helicopters with vertical take-off and landing capabilities will be designed with a coaxial rotor structure featuring 2 rotors rotating on top of each other and in opposite directions, and the rotational force that will occur in the helicopter body will be eliminated by using a differential gearbox in the rotor drive system.

[0025] By increasing the helicopter rotor speed and reducing the rotor diameter, the helicopter will be made more compact and dynamic. It will be enabled to take off and land from smaller areas compared to existing helicopters.

[0026] Horizontal turning of the helicopter to the right or left will be provided by changing the power balance of the rotational movement at the output of the differential gearbox in an electronic environment.

[0027] The horizontal balance of the helicopter will be provided by a propeller-motor system placed on the sides of the helicopter.

[0028] With the above structure, the helicopter body can be manufactured symmetrically.

[0029] With the symmetrical manufacturing of the helicopter body, side winds will affect the front and rear parts of the helicopter body equally, and the volume in the helicopter body will expand.

[0030] The helicopter will be made more compact and given a dynamic structure.

[0031] Detailed Description of the Invention

[0032] The subject of this patent is a helicopter with a coaxial rotor structure, where the rotation of the rotors is driven by a differential gearbox:

[0033] What is a differential gearbox?

[0034] “Differential gearboxes, by their nature, have equal rotational torques on their output shafts. They are used in various fields due to this characteristic, especially the automotive sector. In the automotive sector, differential gearboxes are used to transmit the rotational movement from the gearbox to the wheels with equal torque. The output torques of differential gearboxes are equal, but their speeds can vary. This facilitates the turning ability of cars and tolerates the diameter difference in worn or underinflated tires. In the automotive sector, the output of the differential gearbox transmits rotational movement to the wheels from 2 separate sides and rotating in the same direction. In a 2-wheel drive car (front- wheel drive or rear- wheel drive vehicles), the reason why the car slips and the other wheel does not turn when one wheel comes to a slippery surface is due to the differential gearbox. At the differential gearbox outputs, the torques are the same, but the speeds are different. The total speed of the two outputs is related to the input speed of the differential gearbox. The rotation of the 2 wheels cannot exceed the total speed. Example: If the total speed is 120 rpm, one wheel can rotate at 55 rpm and the other wheel at 65 rpm. If one wheel is rotating at 120 rpm, the other wheel's speed is 0 rpm. The rotational speed limit has been reached. That is, the car is slipping. For differential gearboxes to be used in helicopters with a coaxial rotor structure, their outputs must be on the same side and their rotation directions must be opposite. In this way, when rotational force is applied to the rotors, these forces cancel each other out and do not create a rotational force on the helicopter body.'"

[0035] The patent numbered TR 2021 / 009347, titled 'Differential Gearbox with Oppositely Rotating Shafts and Output Shaft on the Same Side,' designed for use in helicopters, belongs to our company. The gearbox structure described in this patent may have the structure in patent number TR2021 / 009347 or it may be a differential gearbox with a different structure. This is because this patent is not about the differential gearbox structure itself. It is about a helicopter with a coaxial rotor structure driven by a differential gearbox.

[0036] Figures 3, 4, and 5 are images of helicopters with a coaxial rotor structure driven by a differential gearbox.

[0037] Figure 3 is a side view of the helicopters with a coaxial rotor structure driven by a differential gearbox, which is the subject of the patent. Depending on the number of engines, the helicopter body (1) has engine- 1 (2) and engine-2 (3).

[0038] The rotational movement of engine- 1 (2):

[0039] The rotational movement of engine- 1 (2) is transmitted to the differential gearbox (4) via the movement transmission shaft between the engine- 1 (2) and the differential gearbox (2.1).

[0040] The rotational movement of engine-2 (3) is transmitted to the differential gearbox (4) via the movement transmission shaft between the engine-2 (3) and the differential gearbox (3.1). The differential gearbox (4) has 2 rotational movement output shafts on the same side (upper side).

[0041] The movement transmission shaft between the lower rotor and the differential gearbox

[0042] (6) and

[0043] The movement transmission shaft between the upper rotor and the differential gearbox

[0044] (7).

[0045] The movement transmission shaft between the lower rotor and the differential gearbox (6) is connected to the lower rotor (8) and transmits the rotational movement to the rotor (8).

[0046] The movement transmission shaft between the upper rotor and the differential gearbox (7) is connected to the upper rotor (9) and transmits the rotational movement to the upper rotor (9). The rotational movements of the lower rotor (8) and the upper rotor (9) are in opposite directions. Figure 6 lower rotor rotation direction (20), upper rotor rotation direction (21). The lower rotor rotation direction (20) and the upper rotor rotation direction (21) are opposite to each other, and due to the characteristic of the differential gearbox (4), their speeds may not be equal, but their rotational torques are equal. Example: While the upper rotor (9) produces 500 kg / m of torque clockwise, the lower rotor (8) produces 500 kg / m of torque counterclockwise. Since the two rotations are in opposite directions, 500 kg / m - 500 kg / m = 0 kg / m. That is, the rotational force created in the helicopter body (1) is "0" and the helicopter body (1) does not rotate around its own axis.

[0047] Having the rotational force created in the helicopter body (1) be "0" does not solve all the problems. The front part of the helicopter body (1.1) or the rear part of the helicopter body (1.2) may be exposed to excessive side winds, or it may be desired for the helicopter to turn horizontally to the right or left. To solve this problem, the torque balance at the output shafts of the differential gearbox (4) needs to be deliberately disrupted. For this purpose, an electric motor-generator (5) has been added to the output of the differential gearbox (4). The motorgenerator (5) is shown in figures 3, 4, 9, 10.

[0048] The motor-generator (5) affects the rotational torque of the lower rotor (8) as follows: a. If positive torque is applied in the direction of rotation of the lower rotor (8), it will try to rotate the helicopter body (1) in the opposite direction by the amount of torque applied. In other words, the helicopter body (1) will experience a torque in the opposite direction equal to the additional rotational torque applied to the lower rotor (8). b. If torque is applied in the opposite direction of the rotation of the lower rotor (8), the helicopter body (1) will try to rotate in the direction of the applied torque by the amount of torque applied. In other words, the helicopter body (1) will experience a torque in the direction of rotation equal to the additional negative rotational torque applied to the lower rotor (8).

[0049] To formulate it simply:

[0050] Rotational torque of the upper rotor (9); 500 kg / m clockwise,

[0051] Rotational torque of the lower rotor (8); 500 kg / m counterclockwise,

[0052] Let's assume the torque applied to the lower rotor (8) by the motor-generator (5) is 10 kg / m in the direction of rotation of the lower rotor (8).

[0053] (Torque of upper rotor (9) 500 kg / m) - (Torque of lower rotor (8) 500 kg / m + Torque of motor-generator (5) 10 kg / m) = The reverse torque created in the helicopter body (1) becomes 10 kg / m. The opposite can be easily calculated with the same mathematical operation.

[0054] The motor-generator (5)'s characteristic of being a motor-generator is for it to work as a motor while producing additional torque in the direction of rotation of the lower rotor (8) and to work as a generator while producing torque in the opposite direction of rotation. The motor-generator (5) can be placed on the movement transmission shaft between the lower rotor and the differential gearbox (6) so that it only affects the lower rotor (8) (Figures 9, 10), or it can be placed on the movement transmission shaft between the upper rotor and the differential gearbox (7) so that it affects the upper rotor (9). It can even be placed as 2 units, one on the movement transmission shaft between the lower rotor and the differential gearbox (6) and one on the movement transmission shaft between the upper rotor and the differential gearbox (7). However, considering the cost and the additional weight it will add to the helicopter, it is more suitable to have 1 motor-generator (5).

[0055] The operation of the motor-generator (5) is as follows (Figure 11):

[0056] The motor-generator (5) is driven by the motor-generator driver (22).

[0057] When the motor-generator (5) works as a motor, current flows from the motorgenerator driver (22) to the motor- generator (5).

[0058] When the motor-generator (5) works as a generator, current flows from the motorgenerator (5) to the motor-generator driver (22). The bidirectional current is shown as bidirectional electric current (26) for the motor-generator.

[0059] The bidirectional current is shown as bidirectional electric current (26) for the motorgenerator. The motor- generator driver (22) is controlled by the helicopter body position determining electronic unit (23). The information flow between the two units is provided by the control data (30) going from the helicopter body position determining electronic unit to the motor-generator driver.

[0060] The energy of the helicopter body position determining electronic unit (23) is provided by the electric power unit (25) via the helicopter body position determining electronic unit power input (28).

[0061] While the helicopter body position determining electronic unit (23) generates data to keep the helicopter in the same position, it may be desired to manually disrupt this information. Example: the helicopter body (1) may be desired to be turned to the right or left.

[0062] This request is created in the manual control unit (24) and is transmitted to the helicopter body position determining electronic unit (23) via the control data (31) going from the manual control unit to the helicopter body position determining electronic unit. The energy requirement of the manual control unit (24) is met by the electric power unit (25) via the manual control unit power input (29).

[0063] To solve this problem, our company has developed the patent numbered TR2021 / 007755, titled 'Control of Propeller Powers of Vertical Take-off and Landing Aircraft with Coaxial and Tandem Systems'. This patent deals with the equalization of the rotational forces of the propellers with the differential gearbox, and the compensation of possible inequalities or the optional and controlled modification of the equality. The horizontal turning of the helicopter body (1) to the right and left is achieved with the differential gearbox (4) and the electric motor-generator (5), providing energy savings compared to other helicopters and allowing for much more dynamic control. This feature is an important element in helicopters used in challenging conditions and on the battlefield.

[0064] While the horizontal turning of the helicopter body (1) to the right and left can be dynamically controlled with the differential gearbox (4) and the electric motor- generator (5), the balance of the helicopter body (1) with respect to the horizontal plane must also be kept under control. In helicopters manufactured so far, this operation has been carried out through the swashplate mechanism (14). However, in the helicopters intended with this patent, the goal is to make the structure more dynamic by increasing the speeds of the lower rotor (8) and the upper rotor (9) and reducing their diameters. Therefore, it is not considered to use the swashplate mechanism (14) currently used in helicopters. Side motors (17) and side propellers (18) are used to keep the balance of the helicopter body (1) with respect to the horizontal plane under control. Side motors (17) and side propellers (18), as seen in Figures 4 and 5, will be placed on the sides of the helicopter, a minimum of 4 units, in a way that creates a vertical lifting force on the sides of the helicopter. Side motors (17) and side propellers (18) will keep the helicopter balanced relative to the horizontal axis with the lifting force they create on the sides of the helicopter, and they will also enable this balance to be intentionally disrupted in a controlled manner according to demand.

[0065] Example: Raising or lowering the front part of the helicopter body (1.1) relative to the horizontal plane, tilting the helicopter to the right or left.

[0066] Side motors (17) and side propellers (18) can be electric motor-propellers or fuel motorpropellers. Example: Turbojet engine.

[0067] Side motors (17) and side propellers (18) can be electric, fuel motor-propellers, or a hybrid structure consisting of a fuel motor and an electric motor. Aiming for the same purpose; the selection and number of side motors (17) and side propellers (18) may vary depending on the size, weight, load to be carried, and the requested dynamic structure of the helicopter.

[0068] The helicopter to be designed with the technology developed with this patent will be more compact and dynamic in structure compared to existing helicopters. The helicopter will be able to take off and land from narrower areas, and will become usable in challenging weather conditions. Especially the dynamic structure will provide advantages for the military use of the helicopter. Since it will not require a tail, the helicopter body (1) can be made symmetrically. With a symmetrical helicopter body, it will be able to carry more people and / or cargo. When used for military purposes, an observer or co-pilot can be seated in the rear. A structure suitable for bidirectional use with two pilots will be created. The swashplate mechanism used in the rotor system that creates the lifting force of a helicopter; a. Changes the upward lifting force of the rotors by changing the blade pitch angle of the rotor. b. Provides the horizontal balance of the helicopter by changing the blade pitch angle (12) at different points of the rotor's rotation angles. c. Allows the desired movement in the horizontal plane to be given to the helicopter by deliberately disrupting the horizontal balance of the helicopter by changing the blade pitch angle (12) at different points of the rotor's rotation angles.

[0069] With the technology of the helicopter developed with this patent, there will be no need for a swashplate mechanism, the blade pitch angle changing mechanism will not be used at all, or the blade pitch angle changing mechanism used in propeller aircraft will be used.

[0070] The blade pitch angle changing mechanism used in propeller aircraft does not change the blade pitch angle at different rotation angles of the propeller; the blade pitch angle of the propeller remains the same in all parts of the 360-degree rotation. Therefore, it has no effect on the propeller rotation speed. The blade pitch angle changing mechanism used in propeller aircraft can change the blade pitch angle in some aircraft to be completely reversed (to create a pushing force instead of a pulling force of the propeller). These propeller aircraft are especially used for landing on glaciers in places close to the poles. The angle of the propeller blades is changed to be the exact opposite angle, creating braking power for the aircraft.

[0071] Description of the Figures

[0072] FIGURE- 1 : Classic helicopter with a single rotor and tail rotor (15).

[0073] FIGURE-2 : Dual-rotor helicopter with coaxial rotors and tail flaps (16).

[0074] FIGURE-3 : Side view of the principle structure of a helicopter with a coaxial rotor structure driven by a differential gearbox (4).

[0075] FIGURE-4 : Front view of the principle structure of a helicopter with a coaxial rotor structure driven by a differential gearbox (4).

[0076] FIGURE-5 : Top view of the principle structure of a helicopter with a coaxial rotor structure driven by a differential gearbox (4).

[0077] FIGURE-6 : Rotation directions of the rotors of a helicopter with a coaxial rotor structure. FIGURE-7 : Swashplate effect on the rotor rotation direction and rotation angle of a singlerotor helicopter.

[0078] FIGURE-8 : Angle of the rotor blades of a single-rotor helicopter changed by the swashplate relative to the horizontal ground.

[0079] FIGURE-9 : Side view of the electric motor-generator (5) placed on the movement transmission shaft between the lower rotor and the differential gearbox (6). FIGURE- 10 : Top view of the electric motor-generator (5) placed on the movement transmission shaft between the lower rotor and the differential gearbox (6).

[0080] FIGURE- 11 : Electric motor-generator (5) control system theory.

[0081] Explanation of the Reference Numbers used in the Figures:

[0082] 1. Helicopter body,

[0083] 1.1. Front part of the helicopter body,

[0084] 1.2. Rear part of the helicopter body

[0085] 2. Motor- 1

[0086] 2.1. Movement transmission shaft between Motor-2 and differential gearbox,

[0087] 3. Motor-2,

[0088] 3.1. Movement transmission shaft between Motor-2 and differential gearbox,

[0089] 4. Differential gearbox

[0090] 5. Electric motor-generator

[0091] 6. Movement transmission shaft between lower rotor and differential gearbox

[0092] 7. Movement transmission shaft between upper rotor and differential gearbox

[0093] 8. Lower rotor

[0094] 9. Upper rotor

[0095] 10. Single rotor

[0096] 11. Rotor blades

[0097] 12. Rotor blade pitch angle

[0098] 13. Landing gear

[0099] 14. Swashplate mechanism

[0100] 14.1. Lower rotor swashplate mechanism

[0101] 14.2. Upper rotor swashplate mechanism

[0102] 15. Tail rotor

[0103] 16. Tail flaps

[0104] 17. Side motors

[0105] 18. Side propellers

[0106] 19. Single rotor rotation direction

[0107] 20. Lower rotor rotation direction

[0108] 21. Upper rotor rotation direction

[0109] 22. Motor-generator driver

[0110] 23. Helicopter body position determining electronic unit

[0111] 24. Manual control unit

[0112] 25. Electric power unit

[0113] 26. Bidirectional electric current for motor-generator

[0114] 27. Bidirectional electric current for power unit

[0115] 28. Helicopter body position determining electronic unit power input

[0116] 29. Manual control unit power input Control data from helicopter body position determining electronic unit to motorgenerator driver Control data from manual control unit to helicopter body position determining electronic unit

Claims

CLAIMS1. Helicopter with a coaxial rotor structure, where the rotation of the rotors is driven by a differential gearbox, characterized in that: incorporating the properties such that having a coaxial (upper and lower 2 rotors) rotor structure of the helicopter, and the lower rotor (8) and upper rotor (9) being driven by a differential gearbox (4) with output shafts on the same side, rotating in opposite directions from each other, for the horizontal right-left turning movement of the helicopter body (1); changing the torque of the movement transmission shaft between the lower rotor and the differential gearbox (6) and / or the movement transmission shaft between the upper rotor and the differential gearbox (7) with an electric motor-generator (5).

2. As stated in Claim 1 ; it is a helicopter with a coaxial rotor structure where the rotation of the rotors is driven by a differential gearbox, characterized in that: for making the horizontal right- left turning movement of the helicopter body (1) more dynamic; performing the right-left turning movement electrically with an electric motorgenerator (5).

3. As stated in Claim 1; it is a helicopter with a coaxial rotor structure where the rotation of the rotors is driven by a differential gearbox, characterized in that: the balance of the helicopter body (1) relative to the horizontal plane and / or the control of movement relative to the horizontal plane is handled with side motors (17) and side propellers (18).

4. Helicopter with a coaxial rotor structure, where the rotation of the rotors is driven by a differential gearbox, characterized in that: incorporating the properties such that to make the helicopter more compact and enable it to take off and land in smaller areas;Instead of using the swashplate mechanism used in helicopters to change the positions of the blade pitch angle (12) of the lower rotor (8) and the upper rotor (9) at certain rotation angles, increasing the rotation speeds of the lower rotor (8) and the upper rotor (9) and reducing the rotor diameters for the same lifting force5. It is a helicopter with a coaxial rotor structure, where the rotation of the rotors is driven by a differential gearbox, characterized in that: eliminating the tail system of the helicopter to provide the ability to be used with a front-rear 2-pilot configuration and / or to increase the internal volume of the helicopter body (1), thus giving it the ability to carry more people and / or cargo.

Images