Axial flux counter-rotating motor, coaxial propulsion device and aircraft

Abstract

The present invention proposes an axial flux counter-rotating motor, a coaxial propulsion device based on the motor, and an aircraft using the propulsion device. The present invention optimizes the structure of the coaxial propulsion device based on the motor while retaining the advantages of the axial flux dual-rotor motor, so that the coaxial propulsion device based on the axial flux counter-rotating motor has the advantages of simple structure, light weight, high heat dissipation efficiency, and easy maintenance compared with similar devices in the prior art. Specifically, for example, based on a motor with a YASA structure, the connection between the first rotor and the second rotor is cancelled, and the magnetic pole direction of the permanent magnet in the second rotor is changed, so that it rotates independently with the first rotor, and drives two sets of blades in opposite directions to form a new type of coaxial propulsion device.

Description

Technical Field

[0001] The invention relates to an axial flux motor and aviation equipment technology. Background Art

[0002] Coaxial counter-rotating propulsion devices are a type of propulsion device commonly used in aircraft, especially rotorcraft. For example, coaxial helicopters represented by the Kasimov series of helicopters and multi-rotor aircraft represented by the DJI FlyCart 30 each use a coaxial counter-rotating propulsion device. Coaxial counter-rotating propulsion devices have a wide range of uses in the fields of aviation and navigation.

[0003] An axial magnetic field dual-rotor motor in the prior art includes two rotors and a stator in the middle (double-sided air gap). The permanent magnets of the two rotors are arranged opposite to each other to achieve the same-direction rotation at both ends of the stator parallel to the magnetic field and the motor shaft, and are connected by two rotor casings to achieve the two rotors outputting power to the outside as a whole, such as a YASA structure motor.

[0004] When using electric drive to achieve coaxial reverse drive, the drive structure of the prior art is a dual motor in parallel or series, and the dual motors are installed in opposite directions on a common bracket, such as DJI FlyCart 30, or a motor with a hollow power output shaft is used, so that the power output shaft of one motor passes through another motor with a hollow power output shaft, or two motors with hollow power output shafts are installed on a common axial bracket, and a single motor is used with the help of a transmission group to achieve coaxial reverse drive. Even when using an axial magnetic field dual-rotor motor, it is necessary to combine the two motors or use a motor plus a transmission group to achieve coaxial reverse drive. Then, under the prior art, for example, when using a YASA structure motor, the following contradiction will occur, that is, in the system, the two originally independent powers of the dual rotors need to be connected with the rotor shell as one power output, and then the coaxial counter-rotation means of the dual motors or single motor plus the transmission group are used to achieve the coaxial counter-rotation dual power output. At this time, the system has serious redundancy and self-contradiction in force transmission logic. Summary of the invention

[0005] In view of the above problems, the present invention proposes an axial flux counter-rotating motor, a coaxial propulsion device based on the motor, and an aircraft using the propulsion device. The axial flux counter-rotating motor simplifies the structure while retaining the performance advantages of the axial flux dual-rotor motor, so that the axial flux counter-rotating motor and the coaxial propulsion device based on the motor have the advantages of simple structure, light weight, high heat dissipation efficiency and easy maintenance.

[0006] The present invention adopts the following technical scheme: based on an axial flux dual-rotor motor, such as a YASA structure motor, the connection between the first rotor and the second rotor is cancelled, and the magnetic pole direction of the permanent magnet in the second rotor is changed so that it rotates independently of the first rotor and outputs power outward. Specifically, that is: an embodiment of the present invention provides a motor, characterized in that the motor includes a bracket, a stator, a first rotor and a second rotor; the bracket is tubular, and the stator, the first rotor and the second rotor are annular; the stator is composed of a combination of axial flux windings, the axial flux windings are installed on the bracket, and the axial flux windings include a winding core and a coil; the first rotor and the second rotor are connected by bearings and the bracket, and the first rotor and the second rotor are installed with permanent magnets on both sides of the stator, on the side facing the stator, and there is an air gap between the permanent magnet and the stator, and the first rotor and the second rotor rotate in opposite directions around the common axis of the bracket under the drive of the stator. In some schemes, the hollow portion of the bracket is used to set up electric wires, electric regulators, etc. for powering the stator, and connecting rods, cables, hydraulic pipes, steering gears and control lines, etc. for controlling the blade pitch changing mechanism. In some schemes, when the hollow space is large enough and the stator is installed on the inner side of the bracket, the hollow space of the tubular bracket can also be used as a maintenance space for the stator. In other schemes, on the contrary, the hollow portion of the bracket is used as a space for the propeller to do work on the fluid, while the outer side of the bracket is used to arrange electric wires, electric regulators, etc. for powering the stator, and connecting rods, cables, hydraulic pipes, steering gears and control lines, etc. for controlling the blade pitch changing mechanism, as well as to provide maintenance space.

[0007] Optionally, the stator, the first rotor, the second rotor, and the bearings connecting the first rotor and the bracket, and the second rotor and the bracket are installed on the outside of the bracket.

[0008] Optionally, the middle part of the bracket protrudes outward, and the protruding part of the bracket wraps the stator on the inner side of the bracket. The first rotor and the second rotor, and the bearings connecting the first rotor and the bracket and the second rotor and the bracket are respectively installed on the outside of the non-protruding part of the bracket. An air gap is left between the side of the first rotor and the second rotor where the permanent magnet is installed and the surface of the protruding part of the bracket that wraps the stator. The material of the protruding part of the bracket, especially the part facing the permanent magnet, is a magnetic conductive material.

[0009] Optionally, the stator, the first rotor, the second rotor, and the bearings connecting the first rotor and the bracket, and the second rotor and the bracket are installed on the inner side of the bracket.

[0010] Optionally, it is characterized in that: the middle part of the bracket protrudes inward, the protruding part of the bracket wraps the stator on the outside of the bracket, the first rotor and the second rotor, and the bearings connecting the first rotor and the bracket and the second rotor and the bracket are respectively installed on the inner side of the non-protruding part of the bracket, and an air gap is left between the side of the first rotor and the second rotor where the permanent magnet is installed and the surface of the inward protruding part of the bracket that wraps the stator, and the material of the protruding part of the bracket, especially the part facing the permanent magnet, is a magnetic conductive material.

[0011] An embodiment of the present invention also provides a propulsion device, which uses any one of the above-mentioned motors and also includes two groups of blades, one forward and one reverse. The angles of attack of the two groups of blades are opposite in the front and rear directions, and they rotate in opposite directions to jointly press the fluid toward the rear. The first group of blades are installed on the first rotor and contact the incoming flow first, and the second group of blades are installed on the second rotor and contact the incoming flow later. The device also has a fairing, which is connected to the bracket.

[0012] Optionally, the pitch of the second group of blades is 1% to 40% greater than the pitch of the first group of blades.

[0013] Optionally, the propulsion device includes two groups of blade pitch changing mechanisms and variable pitch blades, the first group of blade pitch changing mechanisms is used to control the variable pitch blades on the first rotor, and the second group of blade pitch changing mechanisms is used to control the variable pitch blades on the second rotor, and the blade pitch changing mechanism is a blade pitch changing mechanism of the prior art.

[0014] Optionally, the propulsion device also includes two groups of swash plate blade cyclic pitch changing mechanisms and variable pitch blades, the first group of swash plate blade cyclic pitch changing mechanisms is used to control the variable pitch blades on the first rotor, and the second group of swash plate blade cyclic pitch changing mechanisms is used to control the variable pitch blades on the second rotor, the swash plate blade cyclic pitch changing mechanism is a swash plate blade cyclic pitch changing mechanism of a helicopter in the prior art, the swash plate blade cyclic pitch changing mechanism can be tilted or moved axially, and can realize the overall pitch control of the corresponding blade pitch and the control of its pitch periodic change.

[0015] An embodiment of the present invention further provides an aircraft, wherein the aircraft uses any one of the above-mentioned propulsion devices.

[0016] The beneficial effects of the present invention are as follows: compared with the YASA motor in the prior art, the motor provided in the embodiment of the present invention has a simpler overall structure because its stator does not need to be surrounded by a dual rotor group. Compared with the YASA motor in which the stator is surrounded by the rotor on three sides, the stator winding exposed outside the rotor shell has better heat dissipation performance and is easier to maintain; compared with the electric-driven coaxial propulsion device in the prior art, the propulsion device in the embodiment provided by the present invention only needs an axial flux motor drive, which is lighter and simpler than the dual-motor solution and the electric-driven coaxial structure of a single motor plus a gear group; similarly, the aircraft with an electric-driven coaxial counter-rotating propulsion device provided in the embodiment of the present invention also has the characteristics of simple structure and higher thrust-to-weight ratio than similar aircraft in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate a specific implementation of the present invention, the drawings required for use in the specific implementation will be briefly introduced below. Obviously, the drawings described below are an implementation of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A three-dimensional schematic diagram of a propulsion device provided in an embodiment of the present invention;

[0019] Figure 2 for Figure 1 Exploded diagram of the middle propulsion device;

[0020] Figure 3 for Figure 1 A schematic cross-sectional view of the propulsion device;

[0021] Figure 4 A cross-sectional schematic diagram of another propulsion device provided by an embodiment of the present invention;

[0022] Figure 5 A schematic cross-sectional view of a third propulsion device provided in an embodiment of the present invention.

[0023] Reference numerals

[0024] 1-front fairing; 2-first rotor; 3-stator; 4-second rotor; 5-rear fairing; 6-ducted propulsion device fairing; 7-inner wall of ducted propulsion device; 21-blade; 22-bracket; 23-permanent magnet; 24-bearing; 31-bracket; 32-winding; 41-blade; 42-bracket; 43-permanent magnet; 44-bearing; 321-coil; 322-winding core. Implementation

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiment is an embodiment of the present invention, not all embodiments. The components of the embodiments of the present invention generally described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents a selected embodiment of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work based on the methods or embodiments of the present invention belong to the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example

[0028] like Figure 1 , Figure 2 , Figure 3As shown, an embodiment of the propulsion device of the present invention is provided, including 1-front fairing and 5-rear fairing, 3-stator, 2-first rotor and 4-second rotor, blades 21 and blades 41; the 2-first rotor and 4-second rotor respectively include respective 22-brackets and 42-brackets, 23-permanent magnets and 43-permanent magnets, 24-bearings and 44-bearings, blades 21 and blades 41; the 2-first rotor and 4-second rotor are respectively connected by respective 24-bearings and 44-bearings and 31-brackets, and the blades 21 and the blades 41 are connected to the 22-bracket and the 42-bracket respectively; the 3-stator is composed of a 32-winding combination, the 32-winding is installed on the 31-bracket, and the 32-winding includes respective 321-coils and 322-winding cores; the 321-coil is powered by the electric regulator of the motor, and when the 321-coil is powered by the electric regulator, magnetic poles are formed at both ends of the 32-winding, driving the 23-permanent magnets and 43-permanent magnets on the 2-first rotor and the 4-second rotor, so that the 2-first rotor and the 4-second rotor rotate independently in opposite directions.

[0029] like Figure 4 As shown, another embodiment of the propulsion device of the present invention is provided, wherein the 31-bracket protrudes outward at the position where the 3-stator is located in the middle thereof, and the protruding portion of the 31-bracket wraps the 3-stator on the inner side of the 31-bracket, and the 2-first rotor and the 4-second rotor, as well as the 24-bearing and the 44-bearing connecting the 2-first rotor and the 31-bracket, the 4-second rotor and the 31-bracket are respectively installed on the outside of the non-protruding portion of the 31-bracket, and an air gap is left between the side of the 2-first rotor and the 4-second rotor where the 23-permanent magnet and the 43-permanent magnet are installed and the surface of the protruding portion of the 31-bracket wrapping the 3-stator, and the material of the protruding portion of the 31-bracket, especially the portion thereof facing the 23-permanent magnet and the 43-permanent magnet, is a magnetic conductive material.

[0030] like Figure 5 As shown, a third embodiment of the propulsion device of the present invention is provided, wherein the inner diameters of the 2-first rotor, the 4-second rotor and the 31-bracket are enlarged, the 2-first rotor and the 4-second rotor are connected to the inner side of the 31-bracket through the 24-bearing and the 44-bearing respectively, the 21-blade and the 41-blade are respectively installed on the inner side of the 22-bracket and the 42-bracket, the 3-stator drives the 2-first rotor and the 4-second rotor to respectively drive the 21-blade and the 41-blade to rotate in opposite directions at a constant speed, and a 6-ducted propulsion device fairing with a streamlined cross-section is installed at both ends of the head and tail and the periphery of the 31 bracket, forming a new rim-driven ducted propulsion device based on an axial flux counter-rotating motor. Of course, Figure 5 The embodiment shown may also be used Figure 4The method of protruding the bracket and wrapping the stator shown in the illustrated embodiment enables the 3-stator to be installed on the outside of its 31-bracket, so that the present embodiment can still achieve good maintainability in some usage scenarios where it is inconvenient to perform maintenance from the inside of the duct.

[0031] Furthermore, in the embodiment of the above-mentioned propulsion device, the 21-blade and the 41-blade in the same embodiment have the same aerodynamic characteristics but the angle of attack is opposite in the front and rear directions, and the 21-blade and the 41-blade are driven by the 22-bracket and the 42-bracket respectively to rotate in opposite directions at the same speed. When the pitch of the 21-blade and the 41-blade is the same, since the 21-blade receives the fluid disturbed by the 21-blade during operation, at the same pitch, the angle of attack of the 41-blade is smaller than that of the 21-blade. According to the well-known practical experience in the art, at the same pitch, the efficiency of the 41-blade in generating thrust is about 30% lower than that of the 21-blade, and the anti-torque it receives is also about 30% less than that of the 21-blade.

[0032] Furthermore, in order to achieve a balanced anti-torque force during operation of the above-mentioned embodiment of the propulsion device, the pitch of the 41-blade is increased relative to the pitch of the 21-blade until the anti-torque forces generated by the two are balanced at a certain rotation speed.

[0033] Furthermore, the 21-blade and 41-blade of the embodiment of the above-mentioned propulsion device are variable-pitch blades, and the 31-bracket is extended along its axial direction at the head and tail, respectively, and blade pitch changing mechanisms are respectively installed at both ends of the extended 31-bracket, the blade pitch changing mechanism is installed at the front end of the 31-bracket and is connected to each variable pitch 21-blade on the 2-first rotor, and the blade pitch changing mechanism is installed at the rear end of the 31-bracket and is connected to each variable pitch 41-blade on the 4-second rotor. The pitch changes of the 21-blade and the 41-blade are controlled by the axial forward and backward movement of the two groups of blade pitch changing mechanisms, so as to realize the control of the magnitude and direction of the thrust and torque of the embodiment of the propulsion device, so that A fixed-wing aircraft equipped with an embodiment of the propulsion device can achieve a feathering action during gliding and a reverse propeller action during braking; it can also enable a fixed-wing aircraft equipped with an embodiment of the propulsion device, especially a small aircraft with a single-engine configuration, to perform a rolling action without using ailerons, and overcome reverse torque, so that it can adopt a wing with a small aspect ratio, which is convenient for reducing the width of the fuselage and increasing its flexibility of use; when the embodiment of the propulsion device is used for a multi-rotor aircraft, since its pitch controller can control the distribution of lift and torque, a control method can be implemented that keeps the motor speed of the multi-rotor aircraft unchanged and achieves the pitch, yaw, roll and other actions of the multi-rotor aircraft only through pitch control.

[0034] Furthermore, the 21-blade and 41-blade of the embodiment of the above-mentioned propulsion device are variable-pitch blades, and the 31-bracket is extended along its axial direction at the head and tail respectively, and swash plate blade periodic pitch changing mechanisms are respectively installed at both ends of the extended 31-bracket, the swash plate blade periodic pitch changing mechanism is installed at the front end of the 31-bracket and is connected to each variable pitch 21-blade on the 2-first rotor, and the swash plate blade periodic pitch changing mechanism is installed at the rear end of the 31-bracket and is connected to each variable pitch 41-blade on the 4-second rotor. Through the inclination and axial movement of the two groups of swash plate blade periodic pitch changing mechanisms, the total pitch and periodic variation of the pitch of each of the 21-blade and 41-blade are controlled, so that the rotorcraft, especially the coaxial twin-rotor helicopter installed with the embodiment of the propulsion device can achieve lifting, pitching, rolling, yaw and other actions.

[0035] In summary, the above embodiment has the characteristics of simpler structure and lower construction cost. More embodiments can be obtained by replacing the above embodiment with other technologies, such as replacing the above propulsion device embodiment, especially Figure 4 The embodiment of the propulsion device shown is used for underwater vehicles. In this case, the diameter of its stator 3 can be enlarged, and the stator windings 32 can be made small and numerous, thereby achieving an underwater silent, low electromagnetic wave stealth propulsion effect with large pitch, large propeller disc, large thrust, low speed and low current.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate some technical solutions for implementing the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the fields of aviation and navigation should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the present invention.

Claims

1. A propulsion device, characterized in that: It includes a motor, blades and a fairing, wherein the motor includes a bracket, a stator, a first rotor and a second rotor; the bracket is tubular, and the stator, the first rotor and the second rotor are annular; the stator is composed of a combination of axial magnetic flux windings, the axial magnetic flux windings are installed on the bracket, and the axial magnetic flux windings include a winding core and a coil; the first rotor and the second rotor are connected to the bracket through bearings, and the first rotor and the second rotor are installed with permanent magnets on both sides of the stator, on a side facing the stator, and an air gap is provided between the permanent magnet and the stator, and the first rotor and the second rotor rotate in opposite directions around the common axis of the bracket under the drive of the stator; the blades include two groups of blades, one positive and one negative, and the two groups of blades are connected to the first rotor and the second rotor respectively, and the fairing The cover and the bracket connect the two groups of blades, one positive and one negative, with their angles of attack being opposite in front and back directions. The two groups of blades rotate in opposite directions around the motor shaft to jointly press the fluid backwards. The first group of blades are connected to the first rotor and contact the incoming flow first, and the second group of blades are connected to the second rotor and contact the incoming flow later. The propulsion device includes two groups of inclined disk blade periodic pitch change mechanisms and variable pitch blades, so that their brackets are extended along their axial direction at the head and tail respectively, and inclined disk blade periodic pitch change mechanisms are respectively installed at both ends of the extended bracket. The first group of the two groups of inclined disk blade periodic pitch change mechanisms are installed on one side of the first rotor to control the variable pitch blades on the first rotor, and the second group of the two groups of inclined disk blade periodic pitch change mechanisms are installed on one side of the second rotor to control the variable pitch blades on the second rotor.

2. The propulsion device according to claim 1, characterized in that: The stator, the first rotor and the second rotor, and the bearings connecting the first rotor and the bracket, and the second rotor and the bracket are installed on the outside of the bracket.

3. The propulsion device according to claim 1, characterized in that: The middle part of the bracket protrudes outward, and the protruding part of the bracket wraps the stator on the inner side of the bracket. The first rotor and the second rotor, and the bearings connecting the first rotor and the bracket and the second rotor and the bracket are respectively installed on the outside of the non-protruding part of the bracket. An air gap is left between the side of the first rotor and the second rotor where the permanent magnet is installed and the surface of the protruding part of the bracket that wraps the stator. The material of the part of the protruding part of the bracket facing the permanent magnet is a magnetic conductive material.

4. The propulsion device according to claim 1, characterized in that: The stator, the first rotor, the second rotor, and the bearings connecting the first rotor and the bracket, and the second rotor and the bracket are installed on the inner side of the bracket.

5. The propulsion device according to claim 1, characterized in that: The middle part of the bracket protrudes inward, and the protruding part of the bracket wraps the stator on the outside of the bracket. The first rotor and the second rotor, and the bearings connecting the first rotor and the bracket and the second rotor and the bracket are respectively installed on the inner side of the non-protruding part of the bracket. An air gap is left between the side of the first rotor and the second rotor where the permanent magnet is installed and the surface of the bracket wrapping the stator due to the protruding part, and the material of the part of the protruding part of the bracket facing the permanent magnet is a magnetic conductive material.

6. An aircraft, characterized in that: It comprises one of the propulsion devices described in any one of claims 1 to 5 and a body.

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