Axial flux motor structure capable of automatically changing air gap and design method thereof

Abstract

The invention relates to the technical field of axial magnetic flux motors, and discloses an axial magnetic flux motor structure capable of automatically changing air gaps and a design method of the axial magnetic flux motor structure. The rotor disc is arranged on the rotor; the stator is positioned below the rotor disc; the plurality of back plates are uniformly arranged between the rotor disc and the stator; the plurality of permanent magnets are respectively arranged on one surface, close to the stator, of the backboard; the adjusting part comprises a centrifugal block arranged on the rotor disc, two top blocks and a connecting shaft, a longitudinal through hole is formed in the centrifugal block, inclined grooves which are away from the rotor and are inclined upwards are formed in the two sides of the through hole in the bottom of the centrifugal block, the two top blocks are both arranged on the rotor disc and located in the two inclined grooves respectively, and the connecting shaft is connected with the connecting shaft. The connecting shaft penetrates through the through hole and the rotor disc to be connected with the back plate, the connecting shaft is in sliding connection with the rotor disc, and the connecting shaft is provided with a baffle ring abutting against the top of the centrifugal block; the structure can automatically adjust the air gap of the axial magnetic flux permanent magnet motor, thereby improving the rotating speed range of the motor, and enabling the motor to obtain a wider application scene.

Description

Technical Field

[0001] This invention relates to the field of axial flux motor technology, and in particular to an axial flux motor structure with an automatically variable air gap. Background Technology

[0002] Axial flux permanent magnet motors are widely used due to their advantages such as high torque density and high power density compared to traditional radial flux motors.

[0003] Currently, most axial flux permanent magnet motor rotors use surface-mounted permanent magnets, which are fixed to the rotor core / back plate. The rotor core / back plate is fixed to the rotor disc, which is fixed in the axial direction and cannot be moved. The stator assembly is a fixed component, and the air gap between the stator and rotor is a fixed value after the stator and rotor components are installed.

[0004] When a motor needs to run at a speed higher than its base speed, the controller is often used to weaken the magnetic field to increase the motor speed. However, most axial flux permanent magnet motors are surface-mounted. Surface-mounted permanent magnet motors have a large air gap magnetic reluctance value, making it very difficult to adjust the air gap magnetic field, and the speed increase is very limited. Summary of the Invention

[0005] This invention proposes an axial flux motor structure with automatic variable air gap to overcome the shortcomings of the prior art. This axial flux motor structure can automatically adjust the air gap of the axial flux permanent magnet motor to improve the motor speed range and enable the motor to have a wider range of applications.

[0006] The technical solution of this invention is: an axial flux motor structure with automatic variable air gap, comprising a rotor and a stator, and further comprising: The rotor disk is mounted on the rotor; the stator is located below the rotor disk; Multiple back plates are evenly arranged between the rotor disc and the stator; Multiple permanent magnets are respectively disposed on the side of the back plate near the stator, and there is a magnetic attraction between the permanent magnets and the iron core of the stator; Multiple adjustment sections are provided, each of which includes a centrifugal block, two top blocks, and a connecting shaft disposed on a rotor disk. The centrifugal block has a longitudinal through hole, and the bottom through hole of the centrifugal block has inclined grooves on both sides that are inclined upward away from the rotor. The two top blocks are disposed on the rotor disk and are respectively located in the two inclined grooves. The connecting shaft passes through the through hole and the rotor disk and is connected to the back plate. The connecting shaft is slidably connected to the rotor disk, and the connecting shaft has a retaining ring that abuts against the top of the centrifugal block. When the rotor rotates, the centrifugal block is subjected to centrifugal force and the action of the two top blocks, which generate a force that tilts upwards towards the outer diameter. When the lifting force of the centrifugal block is greater than the magnetic attraction between the permanent magnet and the stator core, the centrifugal block drives the permanent magnet to move upwards through the connecting shaft, so as to adjust the air gap of the motor.

[0007] In at least one embodiment of the present invention, the connecting shaft is a screw, the bottom end of the connecting shaft is threaded to the back plate, and the diameter of the connecting shaft is smaller than the inner diameter of the through hole.

[0008] In at least one embodiment of the present invention, there are two rotor disks, which are respectively located on the upper and lower sides of the stator. The two rotor disks are connected by a connecting ring fitted outside the stator. One of the rotor disks is connected to the rotor. A permanent magnet, a back plate, and an adjustment part are provided between the two rotor disks and the stator.

[0009] In at least one embodiment of the present invention, the top of the top block is a spherical surface or an inclined surface that fits against the inner wall of the inclined groove.

[0010] In at least one embodiment of the present invention, a plurality of centrifugal blocks are evenly arranged in a circular pattern on a rotor disk, and the through holes are located at the center of each centrifugal block.

[0011] In at least one embodiment of the present invention, the plurality of centrifuge blocks are of equal size, the plurality of centrifuge blocks have the same mass, and the centrifuge blocks are all equidistant from the center of mass of the centrifuge blocks from the motor rotation shaft.

[0012] In at least one embodiment of the present invention, an axial flux motor structure with automatic variable air gap includes a dual-rotor single-stator axial flux motor, a single-rotor single-stator axial flux motor, or a dual-stator dual-rotor axial flux motor.

[0013] A method for designing an axial flux motor with an automatically variable air gap includes the following steps; After the electromagnetic scheme of the axial motor is determined, the magnetic attraction force F between the rotor and stator is calculated using simulation software. 磁吸力 ; The centrifugal force F generated by the multiple centrifugal blocks is calculated using the motor speed n, the mass m of the centrifugal block, and the distance r from the centrifugal block's center of mass to the motor's rotation axis. 离心 ; The angle α between the inclined groove and the horizontal direction and F 离心 The lift F of a single centrifugal block was calculated. 升 ;when Where 'a' is the number of centrifuge blocks 51, i.e. At this time, the centrifugal block drives the permanent magnet to move upward through the connecting shaft in order to adjust the air gap of the motor; When modifying the design scheme or designing derivative product schemes, the critical speed for changing the air gap of the motor can be changed by altering one or more of the following: the mass m of the centrifugal block, the distance r between the centrifugal block's center of mass and the rotation axis, and the angle α between the inclined groove and the horizontal direction.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes an adjustment section consisting of a centrifugal block, two top blocks, and a connecting shaft mounted on a rotor disk. In operation, when the rotor rotates, the centrifugal block, under the influence of centrifugal force and the two top blocks, experiences an upward tilting force towards its outer diameter. When the lift force of the centrifugal block exceeds the magnetic attraction between the permanent magnet and the stator core, the centrifugal block drives the permanent magnet upward via the connecting shaft, thereby adjusting the motor's air gap. Compared to existing technologies, this motor structure maintains the original air gap when stationary or rotating at low speeds, and maintains a high back EMF constant at low speeds, allowing the motor to operate at higher voltages and achieve higher efficiency. At high speeds, the air gap automatically increases with the rotational speed, enabling the motor to achieve a wider speed range to meet the requirements of various applications. Furthermore, the entire air gap adjustment section is simple in structure, requiring no additional control system; it relies solely on mechanical components to adjust the motor's air gap, resulting in high adjustment efficiency and strong system reliability. Attached Figure Description

[0015] Figure 1 This is a side view of the structure of the present invention; Figure 2 For the present invention Figure 1 Schematic diagram of the cross-sectional structure at point A in the middle; Figure 3 For the present invention Figure 2 Detailed structural diagram at point B; Figure 4 This is a top view schematic diagram of the structure of multiple centrifuge blocks of the present invention; Figure 5 This is a force analysis diagram of the structure of the present invention.

[0016] Explanation of reference numerals in the attached figures: 1. Rotor; 2. Stator; 3. Rotor disc; 31. Connecting ring; 4. Permanent magnet; 5. Adjustment section; 51. Centrifugal block; 511. Through hole; 512. Inclined slot; 52. Top block; 53. Connecting shaft; 6. Back plate. Detailed Implementation

[0017] The accompanying drawings in this invention are not strictly drawn to scale, and the specific dimensions and quantity of each structure can be determined according to actual needs. The drawings described in this invention are merely structural schematic diagrams.

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "inner," "outer," "upper," "lower," "far," "near," "front," and "rear" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Combination Figures 1 to 4 As shown, an axial flux motor structure with automatic variable air gap includes a rotor 1 and a stator 2, and further includes: Rotor disk 3 is mounted on rotor 1; stator 2 is located below rotor disk 3; Multiple back plates 6 are evenly arranged between the rotor disk 3 and the stator 2; Multiple permanent magnets 4 are respectively disposed on the side of the back plate 6 near the stator 2. Specifically, the permanent magnets 4 are bonded to the back plate 6; there is a magnetic attraction between the permanent magnets 4 and the iron core of the stator 2. Multiple adjustment parts 5, each adjustment part 5 includes a centrifugal block 51, two top blocks 52 and a connecting shaft 53 disposed on the rotor disk 3. The centrifugal block 51 is provided with a longitudinal through hole 511. The bottom through hole 511 of the centrifugal block 51 is provided with inclined grooves 512 that are inclined upward away from the rotor 1 on both sides. The two top blocks 52 are disposed on the rotor disk 3 and are respectively located in the two inclined grooves 512. The connecting shaft 53 passes through the through hole 511 and the rotor disk 3 and is connected to the back plate 6. The connecting shaft 53 is slidably connected to the rotor disk 3. The connecting shaft 53 has a retaining ring that abuts against the top of the centrifugal block 51. When rotor 1 rotates, centrifugal block 51, under the action of centrifugal force and the two top blocks 52, generates a force that tilts upwards towards its outer diameter. When the lifting force of centrifugal block 51 is greater than the magnetic attraction between permanent magnet 4 and stator core 2, centrifugal block 51 drives permanent magnet 4 upwards via connecting shaft 53 to adjust the motor air gap. This invention automatically adjusts the air gap according to the rotational speed, eliminating the need for an additional control system to adjust the air gap size. This invention eliminates the need for an additional electrical control system to adjust the air gap, resulting in higher system efficiency. This invention has a simple structure, relying solely on mechanical parts to adjust the motor air gap, leading to higher system reliability and lower cost.

[0021] As an alternative embodiment, the connecting shaft 53 is a screw, and the bottom end of the connecting shaft 53 is threaded to the back plate 6. The diameter of the connecting shaft 53 is smaller than the inner diameter of the through hole 511. The selection of screws facilitates quick connection with the back plate 6 during the assembly process of this motor structure.

[0022] As an alternative embodiment, two rotor disks 3 are provided, located on the upper and lower sides of the stator 2 respectively. The two rotor disks 3 are connected by a connecting ring 31 fitted outside the stator 2. One rotor disk 3 is connected to the rotor 1. Multiple permanent magnets 4 are provided between the two rotor disks 3 and the stator 2. Multiple adjustment parts 5 corresponding to the permanent magnets 4 are provided on the two rotor disks 3. Specifically, the two rotor disks 3 are connected to the connecting ring 31 by screws. The air gap can be adjusted from the two upper and lower directions of the iron core of the stator 2, which can better control the air gap magnetic field of the entire motor structure.

[0023] As an alternative embodiment, the top of the top block 52 is a spherical surface or an inclined surface that fits against the inner wall of the inclined groove 512; the choice of spherical surface or inclined surface allows the top block 52 to better fit with the inner wall of the inclined groove 512, so as to avoid excessive friction between the two, thereby avoiding affecting the movement of the centrifugal block 51 and causing the normal operation of air gap adjustment.

[0024] As an alternative embodiment, multiple centrifugal blocks 51 are evenly arranged in a circle on the rotor disk 3, and through holes 511 are located in the middle of each centrifugal block 51; so that when the centrifugal block 51 is subjected to an upward force, it can drive the connecting shaft 53 to move upward without tilting.

[0025] As an alternative embodiment, the multiple centrifugal blocks 51 are of equal size, have the same mass, and have the same distance from the center of mass of the multiple centrifugal blocks 51 to the rotating shaft of the motor, so that at the corresponding speed, the movement amplitude of each centrifugal block 51 and the adjustment range of the air gap are the same.

[0026] As an alternative embodiment, an axial flux motor structure with automatic variable air gap includes a dual-rotor single-stator axial flux motor, a single-rotor single-stator axial flux motor, or a dual-stator dual-rotor axial flux motor.

[0027] Combination Figure 5 As shown, an axial flux motor structure design method with automatic variable air gap includes the following steps; After the electromagnetic scheme of the axial motor was determined, the magnetic attraction force F between the rotor 1 and the stator was calculated using simulation software. 磁吸力 ; The centrifugal force F generated by multiple centrifugal blocks 51 is calculated using the motor speed n, the mass m of centrifugal block 51, and the distance r from the center of mass of centrifugal block 51 to the motor axis of rotation.离心。 ;

[0028] The angle α between the inclined groove 512 and the horizontal direction and F 离心 The lift of a single centrifugal block 51 was calculated. ;when 'a' represents the number of centrifuge blocks 51, i.e. At this time, the centrifugal block 51 drives the permanent magnet 4 to move upward through the connecting shaft 53 in order to adjust the air gap of the motor; When modifying the design scheme or designing a derivative product scheme, the critical speed for changing the air gap of the motor can be changed by altering one or more of the following: the mass m of the centrifugal block 51, the distance r between the centrifugal block 51's center of mass and the rotation axis, and the angle α between the inclined groove 512 and the horizontal direction; thereby improving the design efficiency of the scheme modification or derivative scheme.

[0029] The protection provided by the above design method allows for the rapid modification of one or more characteristics of the centrifugal block (weight, center of mass, included angle) through calculation and design when different application requirements arise (e.g., the original solution required a larger air gap at 1000 RPM, while the new requirement necessitates a larger air gap at 2000 RPM). This allows for the change of the critical speed at which the air gap changes while keeping other parts unchanged or subject to minor modifications. Modifying the design scheme or designing derivative products is simple and quick; fewer parts are required, reducing design workload, R&D cycle, and material costs.

[0030] The above embodiments are merely specific implementations of this invention patent, used to illustrate the technical solutions of this invention patent, and not to limit it. The protection scope of this invention patent is not limited thereto. Although this invention patent has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in this invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions implemented by this invention patent, and should all be covered within the protection scope of this invention.

Claims

1. An axial flux motor structure with automatic variable air gap, comprising a rotor (1) and a stator (2), characterized in that, Also includes: Rotor disk (3) is mounted on rotor (1); stator (2) is located below rotor disk (3); Multiple back plates (6) are evenly arranged between the rotor disk (3) and the stator (2); Multiple permanent magnets (4) are respectively disposed on the side of the back plate (6) close to the stator (2), and the permanent magnets (4) have magnetic attraction with the iron core of the stator (2); Multiple adjustment parts (5), each adjustment part (5) includes a centrifugal block (51) disposed on a rotor disk (3), two top blocks (52) and a connecting shaft (53). The centrifugal block (51) is provided with a longitudinal through hole (511). The bottom through hole (511) of the centrifugal block (51) is provided with inclined grooves (512) on both sides away from the rotor (1). The two top blocks (52) are disposed on the rotor disk (3) and are respectively located in the two inclined grooves (512). The connecting shaft (53) passes through the through hole (511) and the rotor disk (3) and is connected to the back plate (6). The connecting shaft (53) is slidably connected to the rotor disk (3). The connecting shaft (53) has a retaining ring that abuts against the top of the centrifugal block (51). When the rotor (1) rotates, the centrifugal block (51) is subjected to centrifugal force and the two top blocks (52) to generate a force that tilts upwards towards the outer diameter. When the lifting force of the centrifugal block (51) is greater than the magnetic attraction between the permanent magnet (4) and the stator (2) core, the centrifugal block (51) drives the permanent magnet (4) to move upwards through the connecting shaft (53) to adjust the air gap of the motor.

2. The axial flux motor structure with automatic variable air gap as described in claim 1, characterized in that, The connecting shaft (53) is a screw, and the bottom end of the connecting shaft (53) is threaded to the back plate (6). The diameter of the connecting shaft (53) is smaller than the inner diameter of the through hole (511).

3. The axial flux motor structure with automatic variable air gap as described in claim 1, characterized in that, There are two rotor disks (3), which are located on the upper and lower sides of the stator (2) respectively. The two rotor disks (3) are connected by a connecting ring (31) fitted outside the stator (2). One of the rotor disks (3) is connected to the rotor (1). A permanent magnet (4), a back plate (6) and an adjustment part (5) are provided between the two rotor disks (3) and the stator (2).

4. The axial flux motor structure with automatic variable air gap as described in claim 1, characterized in that, The top of the top block (52) is a spherical surface or an inclined surface that fits into the inner wall of the inclined groove (512).

5. The axial flux motor structure with automatic variable air gap as described in claim 1, characterized in that, Multiple centrifugal blocks (51) are evenly arranged in a circular pattern on the rotor disk (3), and the through hole (511) is located in the middle of each centrifugal block (51).

6. The axial flux motor structure with automatic variable air gap as described in claim 1, characterized in that, The centrifuge blocks (51) are of equal size, have the same mass, and the centrifuge blocks (51) are all equidistant from the motor rotation shaft.

7. The axial flux motor structure with automatic variable air gap as described in claim 1, characterized in that, This includes dual-rotor single-stator axial flux motors, single-rotor single-stator axial flux motors, or dual-stator dual-rotor axial flux motors.

8. A design method for an axial flux motor structure with automatic variable air gap, based on the axial flux motor structure with automatic variable air gap described in claim 1, characterized in that, Includes the following steps; After the electromagnetic scheme of the axial motor is determined, the magnetic attraction force F between the rotor (1) and the stator is calculated using simulation software. 磁吸力 ; The centrifugal force F generated by multiple centrifugal blocks (51) is calculated by using the motor speed n, the mass m of the centrifugal block (51), and the distance r between the center of mass of the centrifugal block (51) and the motor rotation axis. 离心 ; The angle α between the inclined groove (512) and the horizontal direction and F 离心 The lift F of a single centrifugal block (51) was calculated. 升 ;when , where a is the number of centrifuge blocks (51), i.e. At that time, the centrifugal block (51) drives the permanent magnet (4) to move upward through the connecting shaft (53) in order to adjust the air gap of the motor; When modifying the design scheme or designing a derivative product scheme, the critical speed for the change of the motor air gap can be changed by changing one or more of the following: the mass m of the centrifugal block (51), the centrifugal block (51) centroid, the distance r of the rotation axis, and the angle α between the inclined groove (512) and the horizontal direction.

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