JP2021133768A - Electric variable pitch type flying body - Google Patents

Abstract

To improve flight stability relating to a flying body that vertically ascends and descends.SOLUTION: An electric variable pitch type flying body includes propeller blades of which angles are of electrically variable-pitch type to thereby improve flight stability, in a flying body capable of vertically taking off and landing or in a variable pitch propeller mechanism for a flying body with fan blades.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electrically variable pitch type flying object that vertically ascends and descends, and aims to improve flight stability by making the angle of the propeller blades an electric variable pitch type.

In recent years, improvements in sensors and software used for attitude control of unmanned aerial vehicles, so-called drones, and autonomous flight have progressed, and the performance and operability of unmanned aerial vehicles have dramatically improved. Among unmanned aerial vehicles, helicopters and multicopters capable of vertical takeoff and landing have the advantage of not requiring a runway. Furthermore, especially multicopters that fly with multiple propellers have a simpler rotor structure than helicopters, and are easier to design and maintain, so their application to various missions in a wide range of industrial fields is being considered. ..
Although it is widely used in the field of unmanned small aircraft, there is a problem that the flight attitude becomes unstable during hovering in the field of large electric unmanned aerial vehicles on which several humans are on board. The reason for this is that the thrust is performed by changing the rotation speed of the propeller, so that the time response to disturbances such as crosswinds is low. That is, a time delay occurs in the attitude restoration during hovering, and the flight attitude becomes unstable. In order to solve these problems, a method has been devised to stabilize the posture by attaching a large number of propellers, but originally, if it is not composed of about 2 to 3 electric propeller units, it consumes a lot of power during hovering. This will affect the cruising range and other factors. For this reason, there has been a demand for a technique for stabilizing the flight attitude by directly changing the pitch of the propeller to shorten the response time instead of controlling the thrust of the electric propeller unit by controlling the rotation speed.

By the way, a general rotary wing type machine used in a multicopter has an excellent hovering ability because it has a rotary wing for ascending having a vertical axis. In addition, when flying horizontally, the aircraft is tilted in the direction of travel so that it descends forward to obtain thrust forward. That is, in order to obtain thrust in the horizontal direction, the rotorcraft tilts the aircraft by changing the number of rotations of the front and rear rotors, and changes the pitch angle of the rotors. By changing the pitch angle of the rotary wing in this way, the rotary wing type aircraft can fly horizontally. As an existing variable pitch propeller device, for example, there are devices described in Patent Documents 1 and 2.

Japanese Patent No. 6592679 Special Table 2019-516619 Gazette

In view of the above problems, the present invention uses a synchronous differential transmission having a mechanical rotation synchronization mechanism at the tip of a propeller having a variable pitch mechanism and a pitch variable motor provided at a fixed portion to drive the thrust of the hovering machine. By changing the pitch of the blades, it is controlled instantly to stabilize the aircraft and solve the problems. Further, because of the mechanical rotation synchronization mechanism, there is an advantage that power consumption can be reduced because the pitch variable motor is stopped except when the blade pitch is variable. In addition, the variable pitch mechanism of the blades does not need to have a through hole inside the rotating spindle by providing a pitch variable mechanism at the tip of the rotating spindle, and can be used by the power of an internal combustion engine other than an electric motor or an engine such as a dregs turbine. An electric variable pitch mechanism can be provided.

The present invention is as shown below.
<1> A variable-pitch propeller mechanism in a variable-pitch propeller mechanism of an air vehicle capable of vertical takeoff and landing or an air vehicle having fan blades, wherein a mechanical synchronous differential transmission is provided in the rotary propeller mechanism portion.
<2> The mechanical synchronous differential transmission is characterized in that it is provided on the output shaft side of a motor for rotating blades and a motor for variable pitch is provided on a stationary portion at the tip of the synchronous differential transmission. , <1> The variable pitch propeller mechanism.
<3> The variable pitch propeller mechanism according to claim 1, wherein the variable pitch blade and the variable pitch mechanism are housed inside a cylindrical duct. ..
<4> The mechanical synchronous differential transmission is characterized in that a compact and lightweight reduction gear with less backlash is provided on the output shaft side of the synchronous differential transmission in <1> to <3>. Described variable pitch propeller mechanism.
<5> The variable pitch propeller mechanism according to <2> to <4>, wherein the pitch variable motor is attached to a rectifying stay provided inside a duct.
<6> In the variable pitch propeller mechanism according to <1> to <5>, the power for rotating the propeller is an electric motor, a piston engine, a jet engine, or another internal combustion engine. Variable pitch propeller mechanism.

According to the present invention, various effects typified by the following (1) to (7) can be obtained.
(1) By mounting the synchronous differential transmission on the output shaft side of the blade rotation motor, the pitch angle of the blades can be changed quickly, so that the attitude is stable against disturbances such as crosswinds during hovering. Control is possible.
(2) Since the synchronous differential transmission always rotates in synchronization with the blade rotation motor, there is no fluctuation in the blade pitch and stable thrust can be obtained.
(3) A plurality of blades of about 6 to 8 can be attached, and a large thrust can be obtained.
(4) The pitch variable motor operates only when the pitch angle of the blades is changed, and is in a stopped state at other times, so that the power consumption is extremely low.
(5) Since the blades are provided in a cylindrical duct, a larger thrust can be obtained with the same torque than without the duct in order to suppress the air flow generated in the circumferential direction.
(6) Since the blade rotation motor does not need to have a hollow shaft, it can be rotationally driven by an internal combustion engine, a gas turbine, or the like in addition to the electric motor, and stable hovering is possible.
(7) Highly accurate blade pitch control is possible by using a speed reducer with less backlash.

The block diagram in the 1st Embodiment of this invention. Sectional drawing of the synchronous differential transmission as the 1st Embodiment of this invention. The operation explanatory drawing of the planetary gear of the synchronous differential transmission of this invention. The operation explanatory drawing of the planetary gear of the synchronous differential transmission of this invention. The block diagram of the reduction gear as the 1st Embodiment of this invention.

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

FIG. 1 shows a configuration diagram according to the first embodiment of the present invention.
In FIG. 1, a blade rotation motor 6 is firmly supported inside the duct 4 by a stay 7b fixed inside the duct 4. The rotary motor 6 has a rotary motor output shaft 6a, and a holder 9 is fixed via a coupling joint 8.
When the rotation motor output shaft 6a rotates, the holder 9 rotates at the same time via the coupling joint 8.
Inside the holder 9, a synchronous differential transmission 1 and a speed reducer 3 for decelerating the rotation speed of the output shaft 11 of the synchronous differential transmission 1 and increasing the rotational torque are provided.
A bevel gear is attached to the tip of the variable pitch motor output shaft 10 of the speed reducer 3, and the rotational force is transmitted to the blades 5 via the bevel gear. A fixed shaft 16 is provided on the upper portion of the synchronous differential transmission 1 and is fixed to a stay 7a fixed inside the duct 4 via a connecting metal fitting.
Further, a variable pitch motor 10 for changing the pitch of the blades is attached to the stay 7a. Two to eight blades 5 are arranged at equal intervals on a plane when viewed from the upper surface of the drawing, and when the input shaft 7 of the synchronous differential transmission 1 operates, each blade changes at the same angle. It is provided.
The input shaft 7 connected to the variable pitch motor 2 is kept stationary except that the pitch of the blades 5 is changed.
The speed reducer 3 has a structure with less backlash so that a large error does not occur in the angle of the blades.
The rotary motor 6 may be of any type of an internal combustion engine such as an electric motor or a piston engine, or a drive device such as a gas turbine. When the fan part of the turbojet engine used in an aircraft is made into a variable pitch mechanism by the houn method, it becomes easy to adjust the maximum thrust and the speed at a light load during cruising, and fuel consumption is reduced.

The structure of the synchronous differential transmission as the first embodiment of the present invention is shown in FIG.
In the synchronous differential transmission 1 integrally fixed to the top of the holder 9 in FIG. 2, the case 15 is fixed to the holder 9. A fixed shaft 16 is inserted into the top wall thereof, and a bearing 16a makes the case 15 rotatable with respect to the fixed shaft 16. An input shaft 7 that is rotationally driven by a variable pitch motor 2 is concentrically inserted into the fixed shaft 16, and is rotatably supported by a bearing 19 and a shaft support 20. A first sun gear 21 is integrally formed in the lower portion of the input shaft 7, and the first sun gear 21 revolves around the first sun gear 21. The planetary gear 22 of the above is fitted.
On the other hand, a fixed sun gear 26 is integrally formed at the lower end of the fixed shaft 16, and on the outer periphery of the fixed sun gear 26, the fixed sun gear 26 meshes with the fixed sun gear 26 and rotates on its axis. A plurality of second planetary gears 27 that revolve around the center are arranged. Further, a first internal gear 31 arranged concentrically with the fixed sun gear 26 is fixed to the inner surface side of the case 15, and the plurality of second planetary gears 27 are fixed to the internal gear 31. Are meshed.
Further, a second internal gear 32 arranged concentrically with the first sun gear 21 is meshed with the plurality of first planetary gears 22, and the large 2 internal gear 32 is input. It is arranged in the same linear shape as the shaft 7 and is connected to the output shaft 11 penetrating the bottom wall of the case 15.

By the way, on the input shaft 7, a spacer 33 is pivotally supported between the first sun gear 21 and the fixed sun gear 26 via a bearing 34, and bearings 35a and 35b are supported on both upper and lower surfaces of the outer peripheral portion of the spacer 33, respectively. The second planetary gear 27 and the first planetary gear 22 are arranged via the above. Rings 36 and 37 concentric with the input shaft 7 are arranged below the information of the second planetary gear 27 and the first planetary gear 22, respectively, on the ring 36, the spacer 33, and the ring 37. The second planetary gear 27 and the first planetary gear 22 are rotatably supported on the support shaft 38 which is inserted and mounted. Therefore, the number of teeth of the first sun gear 21 and the fixed sun gear 26 are set to Z1 and Z1', respectively, and the tooth number ratio of the two sets of gears is equal as Z1 / Z2 = Z1'/ Z2'= 1 / R. do.
When the holder 9 is rotating at a speed of ω0, the fixed sun gear 26 is in a fixed state, so that the second planetary gear 27 is moved by the first internal gear 31 that rotates together with the holder 9. It is driven and revolves on the revolution locus 40 at a speed of ω1 while rotating as shown in FIG.
On the other hand, when the second planetary gear 27 revolves, if the first sun gear 21 is stopped, the first planetary gear 22 moves to the first sun gear 21 via the support shaft 38 due to the rotational force. The second internal gear 32 and the output shaft 11 are rotated at a speed of ω0'by the rotation of the first planetary gear 22 while rotating around the gear 22 as shown in FIG. ..

By the way, there is the following relationship between the rotation speed of the holder 9, that is, the rotation speed ω0 of the first internal gear 31 and the revolution speed ω1 of the second planetary gear 27.
ω0 = (1 + Z1'/ Z2') ω1
Further, there is the following relationship between the rotation speed ω0'of the output shaft 11, that is, the second internal gear 32, and the revolution speed ω1 of the first planetary gear.
ω0'= (1 + Z1 / Z2) ω1
On the other hand, since the number of teeth is Z1 / Z2 = Z1'/ Z2'= 1 / R as described above, ω0 = ω0', and the output shaft 11 is synchronized and rotated as if it were integrated with the holder 9.
Therefore, although not shown, the input shaft of the speed reducer 3 connected to the output shaft 11 and the variable pitch motor output shaft 10 rotate in synchronization with the holder 9, and are used for the variable pitch. When the motor output shaft 10 is stationary, the variable pitch motor output shaft 10 rotates in synchronization with the holder 9. Therefore, the bevel gear provided at the end of the blade 5 is held in a stationary state and is held at a predetermined pitch angle. Similarly, when the variable pitch motor output shaft 10 rotates, the rotated rotation deviation is transmitted to the pitch variable mechanism of the blades 5 via the speed reducer 3, and the pitch angle changes by a predetermined angle.

Further, the variable pitch motor output shaft 10 of the variable pitch motor 2 may be kept in a stopped state except when the blade pitch is changed. Therefore, when the blade pitch is constant and the rotary motor 6 is rotating, the variable pitch motor 2 only needs to have the holding torque, so that the power consumption is extremely low. If an ultrasonic motor or a motor with a brake that has a holding function when stopped is used for the variable pitch motor 2 in addition to the normal motor, power consumption for maintaining the holding torque becomes unnecessary, so that the power consumption is reduced. Can be planned.

FIG. 5 shows a configuration diagram of the speed reducer of the present invention.
In FIG. 5, Photo 1 shows each component of the speed reducer.
Like the internal gear, there is a tooth pattern for meshing on the inner peripheral side. This is called a circular spline 40. A rotating body that rotates while being fitted inside the circular spline 40 and has a thin wall thickness and elastically deforms is referred to as a flexspline 41. The wave generator 42 is a rotating body that presses the flexspline 41 against the inner peripheral side of the circular spline 40 to rotate it. The number of teeth of the circular spline 40 and the flexspline are different, and the difference in the number of teeth causes the circular spline 40 to rotate while greatly decelerating the rotation speed of the wave generator 42. It is a reducer with a large number of meshing teeth and has extremely little backlash because it rotates while being pressed by the wave generator 42. It is often used as a harmonic drive (registered trademark) reducer for indirect parts such as robots. Has been done.
In the present invention, as a requirement for being used in a speed reducer having a variable pitch mechanism of an air vehicle, it is required to be compact and lightweight and to have no error in the pitch angle of the blades 5. Therefore, if this reduction gear is used, a large reduction ratio can be obtained with a small size and light weight, backlash is reduced, and the pitch angle of the blades 5 can be stably controlled.

1 Synchronous differential transmission 2 Variable pitch motor 3 Reducer 4 Duct 5 Blade 6 Rotating motor 6a Rotating motor Output shaft 7 Input shaft 7a Stay 7b Stay 8 Coupling joint 9 Holder 10 Variable pitch motor Output shaft 11 Output Shaft 15 Case 16 Fixed shaft 16a Bearing 19 Bearing 20 Shaft support 21 Sun gear 22 Planetary gear 26 Fixed sun gear 27 Planetary gear 31 Internal gear 32 Internal gear 33 Spacer 35a Bearing 35b Bearing 36 Ring 37 Ring 38 Support shaft 40 Circular Spline 41 Flex Spline 42 Wave Generator Photo 1 Harmonic Drive® Reducer

Claims (6)

A variable-pitch propeller mechanism in a variable-pitch propeller mechanism of an air vehicle capable of vertical takeoff and landing or an air vehicle having fan blades, characterized in that a mechanical synchronous differential transmission is provided in the rotary propeller mechanism portion. The invention is characterized in that the mechanical synchronous differential transmission is provided on the output shaft side of a motor for rotating blades, and a pitch variable motor is provided on a stationary portion at the tip of the synchronous differential transmission. The variable pitch propeller mechanism according to 1. The variable pitch propeller mechanism according to claim 1, wherein the variable pitch blade and the variable pitch mechanism are housed inside a cylindrical duct in the variable pitch propeller mechanism according to claim 1. The variable pitch propeller according to claims 1 to 3, wherein the mechanical synchronous differential transmission is provided with a compact and lightweight reduction gear having less backlash on the output shaft side of the synchronous differential transmission. mechanism. The variable pitch propeller mechanism according to claim 2 to 4, wherein the pitch variable motor is attached to a rectifying stay provided inside a duct. The variable pitch propeller mechanism according to any one of claims 1 to 5, wherein the power for rotating the propeller is an electric motor, a piston engine, a jet engine, or another internal combustion engine. ..

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