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

Abstract

The invention provides an axial magnetic flux contra-rotating motor, a coaxial propulsion device based on the motor and an aircraft using the propulsion device, and optimizes the structure of the coaxial propulsion device based on the motor on the basis of retaining the advantages of the axial magnetic flux double-rotor motor. Compared with similar devices in the prior art, the coaxial propelling device based on the axial magnetic flux contra-rotating motor has the advantages of being simple in structure, light in weight, high in heat dissipation efficiency, convenient to maintain and the like. Specifically, on the basis of a motor of a YASA structure, connection between a first rotor and a second rotor of the motor is canceled, the magnetic pole direction of a permanent magnet in the second rotor is changed, the second rotor and the first rotor independently rotate oppositely, and two sets of paddles in opposite directions are driven to form the novel coaxial propelling 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 common propulsion device used in aircraft, especially rotary-wing aircraft. 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 of 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 each other to achieve the same-direction rotation at both ends of the stator parallel to the magnetic field and the motor shaft. The two rotor housings are connected to achieve the two rotors output power to the outside as a whole, such as a YASA structure motor.

[0004] When using electric drive to achieve coaxial counter-rotation drive, the existing drive structure involves connecting two motors in parallel or series, with the two motors mounted in opposite directions on a common bracket, such as the DJI FlyCart 30. Alternatively, a motor with a hollow PTO shaft is used, with the PTO shaft of one motor passing through the PTO shaft of the other motor with a hollow PTO shaft, or two motors with hollow PTO shafts are mounted on a common axial bracket, and a single motor with a transmission system is used to achieve coaxial counter-rotation. Even when using an axial magnetic field dual-rotor motor, it is necessary to combine the two motors or use a single motor with a transmission system to achieve coaxial counter-rotation drive. Therefore, under the existing technology, for example, when using a YASA-structured motor, the following contradiction arises: the system first needs to connect the two originally independent power sources of the dual rotors with the rotor housing to output a single power source, and then use the coaxial counter-rotation method of the dual motors or a single motor with a transmission system to achieve the coaxial counter-rotation dual power output. This system then suffers from serious redundancy and self-contradiction in force transmission logic. Summary of the Invention

[0005] In response to the above problems, the present invention proposes an axial flux counter-rotating motor, a coaxial propulsion device based on such a motor, and an aircraft using such a 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 such a motor have the advantages of simple structure, light weight, high heat dissipation efficiency and easy maintenance.

[0006] The present invention adopts the following technical solution: 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, 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. 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 part of the bracket is used to set up electric wires, electric regulators, etc. for powering the stator, and connecting rods, cables, hydraulic pipes, servos and control lines for controlling the blade pitch change 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 part 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, servos and control lines for controlling the blade pitch change 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 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 further 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 being used to control the variable pitch blades on the first rotor, and the second group of swash plate blade cyclic pitch changing mechanisms being 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, and the swash plate blade cyclic pitch changing mechanism can be tilted or moved axially, and can realize collective pitch control of the corresponding blade pitch and control of its pitch cyclic change.

[0015] An embodiment of the present invention further provides an aircraft, which uses any 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 by 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 to drive, which is lighter and simpler than the dual-motor solution and the electric-driven coaxial structure of a single motor plus a gear set; similarly, the aircraft with an electric-driven coaxial counter-rotating propulsion device provided by 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 embodiment of the present invention, the following will briefly introduce the drawings required for use in the specific embodiment. Obviously, the drawings described below are an embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A three-dimensional schematic diagram of a propulsion device provided in an embodiment of the present invention; Figure 2 for Figure 1 Exploded diagram of the middle propulsion unit; Figure 3 for Figure 1 a schematic cross-sectional view of the propulsion device; Figure 4 A schematic cross-sectional view of another propulsion device provided by an embodiment of the present invention; Figure 5 A schematic cross-sectional view of a third propulsion device provided in an embodiment of the present invention. Reference numerals

[0019] 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 Method

[0020] 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 one embodiment of the present invention, not all embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the 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 based on the methods or embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances. Example

[0023] 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-bracket and 42-bracket, 23-permanent magnet and 43-permanent magnet, 24-bearing and 44-bearing, blades 21 and blades 41; the 2-first rotor and 4-second rotor are respectively connected by respective 24-bearing and 44-bearing and 31-bracket, the blades 21 and the blades 41 are respectively connected to the 22-bracket and the 42-bracket; 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 control of the motor. When the 321-coil is powered by the electric control, 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.

[0024] 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. 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, and the 4-second rotor and the 31-bracket are respectively installed on the outside of the non-protruding portion of the 31-bracket. An air gap is left between the side of the 2-first rotor and the 4-second rotor on which 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. 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.

[0025] like Figure 5 As shown, a third embodiment of the propulsion device of the present invention is provided, in which 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 so that they 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 the head and tail ends and the periphery of the 31 bracket to form a new rim-driven ducted propulsion device based on an axial magnetic 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 in the illustrated embodiment enables the 3-stator to be installed on the outside of its 31-bracket, so that this embodiment can still achieve good maintainability in some usage scenarios where it is inconvenient to repair from the inside of the duct.

[0026] Furthermore, in the above-described embodiment of the propulsion device, the 21-blade and 41-blade in the same embodiment have the same aerodynamic characteristics but opposite angles of attack in the fore-aft direction. The 21-blade and 41-blade rotate in opposite directions at the same speed, driven by the 22-bracket and the 42-bracket, respectively. When the pitches of the 21-blade and the 41-blade are the same, since the 21-blade receives the fluid disturbed by the 21-blade during operation, the angle of attack of the 41-blade is smaller than that of the 21-blade at the same pitch. Based on commonly known practical experience in the art, at the same pitch, the efficiency of the 41-blade in generating thrust is approximately 30% lower than that of the 21-blade, and the counter-torque it experiences is also approximately 30% lower than that of the 21-blade.

[0027] Furthermore, in order to achieve a balanced counter-torque during operation of the above-mentioned embodiment of the propulsion device, the pitch of the 41-blade propeller is increased relative to the pitch of the 21-blade propeller until the counter-torques generated by the two are balanced at a certain rotational speed.

[0028] Furthermore, the 21-blades and 41-blades 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 axial forward and backward movement of the two groups of blade pitch changing mechanisms controls the change of the pitch of each of the 21-blades and 41-blades, thereby realizing 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 feathering action during gliding and 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 rolling action and overcome reverse torque without using ailerons, thereby allowing it to adopt wings with a small aspect ratio, facilitating the reduction of the body width and increasing its flexibility of use; when the embodiment of the propulsion device is used in 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 speed of the multi-rotor aircraft motor unchanged and achieves the pitch, yaw, roll and other actions of the multi-rotor aircraft only through pitch control.

[0029] Furthermore, the 21-blades and 41-blades 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 change mechanisms are respectively installed at both ends of the extended 31-bracket. The swash plate blade periodic pitch change 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 change 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 tilting and axial movement of the two groups of swash plate blade periodic pitch change mechanisms, the total pitch and periodic change of the pitch of each of the 21-blades and 41-blades are controlled, so that the rotorcraft installed with the embodiment of the propulsion device, especially the coaxial twin-rotor helicopter, can achieve lifting, pitching, rolling, yaw and other actions.

[0030] 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 the 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 winding 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.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate some technical solutions for implementing the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the aviation and navigation fields should understand that they can still modify the technical solutions described 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: The invention comprises a motor, blades and a fairing, wherein the motor comprises 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 winding of axial magnetic flux, the winding of axial magnetic flux is installed on the bracket, and the winding of axial magnetic flux includes 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 a 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 are connected by bearings and the bracket. Driven by the stator, the blades rotate in opposite directions around the common axis of the stator and the bracket; the blades include two groups of blades, one positive and one negative, which are respectively connected to the first rotor and the second rotor, and the fairing and the bracket are connected to the two groups of blades with their angles of attack being opposite in the front and rear directions. The two groups of blades rotate in opposite directions around the motor shaft and jointly press the fluid backward. 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 pitch of the second group of blades is 1% to 40% larger than that of the first group of blades.

2. 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 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, as well as 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.

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, as well as 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 inward 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.

6. The propulsion device according to claim 1, characterized in that: It includes two groups of blade pitch changing mechanisms and variable pitch blades. The first group of the two groups of blade pitch changing mechanisms is installed on one side of the first rotor to control the variable pitch blades on the first rotor. The second group of the two groups of blade pitch changing mechanisms is installed on one side of the second rotor to control the variable pitch blades on the second rotor.

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

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