Wide-speed-range axial permanent magnet motor rotor and use method thereof

Abstract

The invention discloses a wide-speed-range axial permanent magnet motor rotor and a using method thereof, the wide-speed-range axial permanent magnet motor rotor comprises a plurality of iron core assemblies, permanent magnet assemblies are arranged on the outer surfaces of the iron core assemblies, pressing block assemblies are connected between the outer side walls of the iron core assemblies in a clamped mode, and the iron core assemblies and the pressing block assemblies are detachably connected through compression screws; the iron core assembly is used for supporting the permanent magnet assembly, and the permanent magnet assembly is used for filling the iron core assembly and providing a constant magnetic field; according to the invention, the permanent magnet body is fixed in an embedded manner, so that a reverse salient pole ratio rotor structure function that the D-axis inductance is greater than the Q-axis inductance is realized, and compared with a surface-mounted permanent magnet installation manner, the motor operation constant-power rotating speed range is widened, and the permanent magnet body is prevented from being damaged due to axial magnetic pulling force and radial centrifugal force; the gap between the iron core body and the permanent magnet body is reduced, the compactness of the rotor is improved, the product output precision is improved, and the rotor is suitable for being widely popularized and used.

Description

Technical Field

[0001] The present invention relates to the technical field of axial permanent magnet motors, and particularly relates to a wide-speed-range axial permanent magnet motor rotor and a method for using the same. Background Art

[0002] Axial motors are usually in a flat disc shape, with their stators and rotors arranged in a parallel structure. The magnetic field flows along the axial direction of the motor, and they are structurally compact, with relatively smaller volume and weight. After installing permanent magnets on the rotor disc, compared with traditional radial magnetic field permanent magnet motors, they have higher efficiency and power density, so they are widely used in fields with relatively limited design space, such as electric vehicles, aerospace, and ship propulsion.

[0003] Currently, since axial motors generate torque through the interaction of the axial magnetic field and current, large axial electromagnetic forces will be generated between the stator and rotor of the axial motor during operation. And when the motor is operating at high speed, it will also be subject to large radial centrifugal forces. Currently, permanent magnets in existing axial magnetic field permanent magnet motors are generally surface-mounted on the rotor, resulting in a change in the viscosity of the glue under the conditions of high speed and high temperature, thus weakening the bonding force between the permanent magnet and the rotor surface, and then easily causing the permanent magnet to fall off and damage the motor. Moreover, due to the unique structural characteristics of surface-mounted axial motors, the air gap of the motor is relatively large, the magnetic field generation method is single, and the D-axis and Q-axis inductances are almost the same. At the same time, the demagnetization effect is not obvious when applying D-axis current, so the reluctance torque cannot be utilized, resulting in relatively poor performance of surface-mounted axial motors in weak magnetic control. And the weak magnetic performance of the motor has an important impact on the reliability and stability of the motor operation. Therefore, it is necessary to design a wide-speed-range axial permanent magnet motor rotor and a method for using the same. Summary of the Invention

[0004] The main object of the present invention is to solve the problems that in the existing axial magnetic field permanent magnet motors, since the permanent magnets are generally surface-mounted on the rotor, the viscosity of the glue will change under the conditions of high speed and high temperature, resulting in a weakened bonding force between the permanent magnet and the rotor surface, and thus it is easy for the permanent magnet to fall off and damage the motor. Moreover, due to the unique structural characteristics of the surface-mounted axial motor, the air gap of the motor is relatively large and the magnetic field generation method is single, resulting in relatively poor performance of the axial motor in weak magnetic field control. The weak magnetic field performance of the motor has an important impact on the reliability and stability of the motor operation. The present invention provides a wide-speed-range axial permanent magnet motor rotor and its usage method, which realizes the function of fixing the permanent magnet body in an embedded manner, not only improves the D-axis inductance, but also realizes the design of a reverse salient pole ratio rotor, thereby improving the weak magnetic field control performance of the motor, avoiding damage to the permanent magnet body due to axial magnetic pull and radial centrifugal force, reducing the gap between the iron core body and the permanent magnet body compared with the surface-mounted permanent magnet installation method, improving the compactness of the rotor, and improving the product output accuracy.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: A wide-speed-range axial permanent magnet motor rotor and its usage method, comprising a plurality of iron core components, a permanent magnet component is arranged on the outer surface of the iron core components, and a pressing block component is snap-connected between the outer side walls of the plurality of iron core components, wherein the iron core components and the pressing block component are detachably connected by pressing screws; the iron core components are used to support the permanent magnet component, the permanent magnet component is used to fill the iron core components and provide a constant magnetic field, the pressing block component is used to limit the position of the permanent magnet component and the iron core components and cooperate with the plurality of iron core components to form a ring, and the pressing screws are used to detachably connect the iron core components and the pressing block component.

[0006] For the aforementioned wide-speed-range axial permanent magnet motor rotor, the iron core component includes an iron core body, an iron core groove is opened on the upper surface of the iron core body, and a first clamping groove is opened on the outer wall of the opening end of the iron core groove; a fan-shaped thread groove is opened on the outer side wall of the iron core body.

[0007] For the aforementioned wide-speed-range axial permanent magnet motor rotor, the permanent magnet component includes a permanent magnet body, a side groove is opened on the outer surface of the permanent magnet body, and a second clamping groove is opened on the outer side wall of the permanent magnet body; the inner side wall of the side groove is mutually wedged with the inner side wall of the iron core groove, the opening depths of the first clamping groove and the second clamping groove are the same, and the permanent magnet body is made of silicon steel sheet material.

[0008] The aforementioned rotor of a wide - speed - range axial permanent - magnet motor, the pressing block assembly includes a pressing block body, a groove is provided on the outer side wall of the pressing block body, and a semi - circular threaded groove is provided on the outer wall of the bottom surface of the pressing block body; the inner side wall of the groove is mutually wedged with the inner side walls of the first clamping groove and the second clamping groove, and a pressing screw is used for threaded connection between the sector - shaped threaded groove and the semi - circular threaded groove.

[0009] The aforementioned rotor of a wide - speed - range axial permanent - magnet motor, the number of both the first clamping groove and the second clamping groove is two, and the two first clamping grooves are symmetrically distributed on the outer side wall of the iron core body, while the two second clamping grooves are symmetrically distributed on the outer side wall of the permanent - magnet body.

[0010] The aforementioned rotor of a wide - speed - range axial permanent - magnet motor, the number of the grooves is two, and the two grooves are symmetrically distributed on the outer side wall of the pressing block body, wherein the pressing block body is located at the middle position between two adjacent iron core bodies.

[0011] The aforementioned rotor of a wide - speed - range axial permanent - magnet motor, the number of the iron core body, the permanent - magnet body, the pressing block body and the pressing screw is the same, and multiple iron core bodies, permanent - magnet bodies, pressing block bodies and pressing screws can form a ring.

[0012] A using method of a rotor of a wide - speed - range axial permanent - magnet motor includes the following steps: Step 1, insertion: Move the permanent - magnet body and align the inner side wall of the side groove with the inner side wall of the iron - core groove and insert it. Then slide the permanent - magnet body and completely embed the permanent - magnet body inside the iron - core body to form a combination of the iron - core body and the permanent - magnet body, and further align the first clamping groove with the second clamping groove. Step 2, assembly: Make the assembled combination of the iron - core body and the permanent - magnet body fit together to form a ring - shape. Then move the pressing block body and align the groove with the first clamping groove and the second clamping groove and slide it in to enable clamping connection between the pressing block body and the iron - core body, and further limit the position between the iron - core body and the permanent - magnet body. Step 3, threaded connection: Screw the pressing screw along the semi - circular threaded groove and the sector - shaped threaded groove to enable detachable connection between the pressing block body and the iron - core body, and further enable detachable connection between adjacent iron - core bodies, thus completing the assembly of the permanent - magnet motor rotor.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. First, move the permanent magnet body and align and insert the inner wall of the side groove with the inner wall of the iron core groove. Then, slide the permanent magnet body and completely embed the permanent magnet body inside the iron core body to form a combination of the iron core body and the permanent magnet body. Further, the first card slot and the second card slot can be made flush. Next, place the assembled combination of the iron core body and the permanent magnet body in contact with each other to form a circular ring shape. Then, move the pressing block body and align the groove with the first card slot and the second card slot and slide it in, so as to engage and connect the pressing block body with the iron core body. Further, the position between the iron core body and the permanent magnet body is limited. Subsequently, screw in the pressing screw along the semi-circular thread groove and the fan-shaped thread groove, so as to detachably connect the pressing block body with the iron core body. Further, adjacent iron core bodies can be detachably connected. In this way, the assembly of the permanent magnet motor rotor is completed, effectively realizing the function that the axial permanent magnet motor rotor fixes the permanent magnet body in an embedded manner, avoiding damage to the permanent magnet body due to axial magnetic pulling force and radial centrifugal force, reducing the gap between the iron core body and the permanent magnet body compared with the surface-mounted permanent magnet installation method, improving the compactness of the rotor, and improving the product output accuracy.

[0014] 2. The present invention uses a pressing block assembly and a pressing screw to fix the permanent magnet body on the iron core body, which not only improves the rotor strength, but also reduces the probability of permanent magnet damage. Moreover, the process of winding the rotor with carbon fiber is omitted, saving raw materials, making the rotor assembly process more simple, and increasing the product yield and stability.

[0015] 3. By using silicon steel sheet material to make the permanent magnet body, the present invention not only reduces the amount of permanent magnet used and the eddy current loss, but also improves the product operation efficiency and reduces energy consumption, and also improves the D-axis inductance of the axial magnetic field permanent magnet motor. When the D-axis inductance is greater than the Q-axis inductance, it is an inverse salient pole ratio structure, which can not only effectively solve the shortcoming of poor weak magnetic ability of the existing axial magnetic field permanent magnet motor, but also broaden the application field of the axial magnetic field permanent magnet motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the iron core assembly structure of the present invention; Figure 3 It is a schematic diagram of the permanent magnet assembly structure of the present invention; Figure 4 It is a schematic diagram of the pressing block assembly structure of the present invention; Figure 5 It is a schematic diagram of the rotor iron core structure of the present invention; Figure 6 It is a schematic diagram of the cross-axis and direct-axis magnetic circuits in the embodiment of the present invention; Figure 7Schematic diagram of quadrature-axis magnetic vector in an embodiment of the present invention; Figure 8 Schematic diagram of direct-axis magnetic vector in an embodiment of the present invention; Figure 9 Variation curve of quadrature-axis and direct-axis inductance in an embodiment of the present invention.

[0017] In the figure: 1. Iron core assembly; 101. Iron core body; 102. Iron core slot; 103. First card slot; 104. Sector-shaped threaded groove; 2. Permanent magnet assembly; 201. Permanent magnet body; 202. Side slot; 203. Second card slot; 3. Pressing block assembly; 301. Pressing block body; 302. Groove; 303. Semi-circular threaded groove; 4. Compression screw. Detailed implementation manners

[0018] To make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific implementation manners.

[0019] As Figures 1-5 shown, a wide-speed-range axial permanent magnet motor rotor and its usage method include a plurality of iron core assemblies 1. A permanent magnet assembly 2 is arranged on the outer surface of the iron core assembly 1, and a pressing block assembly 3 is snap-connected between the outer side walls of the plurality of iron core assemblies 1, wherein the iron core assembly 1 and the pressing block assembly 3 are detachably connected by a compression screw 4; the iron core assembly 1 is used to support the permanent magnet assembly 2, the permanent magnet assembly 2 is used to fill the iron core assembly 1 and provide a constant magnetic field, the pressing block assembly 3 is used to limit the position of the permanent magnet assembly 2 and the iron core assembly 1 and cooperate with the plurality of iron core assemblies 1 to form a ring, and the compression screw 4 is used to detachably connect the iron core assembly 1 and the pressing block assembly 3. The present invention realizes the function of fixing the permanent magnet body 201 in an embedded manner, avoids the damage of the permanent magnet body 201 due to axial magnetic pulling force and radial centrifugal force, reduces the gap between the iron core body 101 and the permanent magnet body 201 compared with the surface-mounted permanent magnet installation method, improves the compactness of the rotor, and improves the product output precision.

[0020] Specifically, the iron core assembly 1 includes an iron core body 101. An iron core slot 102 is opened on the upper surface of the iron core body 101, and a first card slot 103 is opened on the outer wall of the opening end of the iron core slot 102; a sector-shaped threaded groove 104 is opened on the outer side wall of the iron core body 101. By moving the permanent magnet body 201 and aligning and inserting the inner side wall of the side slot 202 with the inner side wall of the iron core slot 102, and then sliding the permanent magnet body 201 and completely embedding the permanent magnet body 201 into the iron core body 101, a combined body of the iron core body 101 and the permanent magnet body 201 is formed, and then the first card slot 103 can be made flush with the second card slot 203.

[0021] Specifically, the permanent magnet assembly 2 includes a permanent magnet body 201. A side groove 202 is formed on the outer surface of the permanent magnet body 201, and a second card slot 203 is formed on the outer side wall of the permanent magnet body 201. The inner side wall of the side groove 202 is engaged with the inner side wall of the iron core groove 102. The first card slot 103 and the second card slot 203 have the same slot depth. The permanent magnet body 201 is made of silicon steel sheet. By fitting the assembled iron core body 101 and the permanent magnet body 201 together to form a circular ring, and then moving the pressing block body 301 and aligning the groove 302 with the first card slot 103 and the second card slot 203 and sliding it in, the pressing block body 301 can be detachably connected to the iron core body 101, and thus the iron core body 101 and the permanent magnet body 201 are limited in position relative to each other.

[0022] Specifically, the pressing block assembly 3 includes a pressing block body 301. A groove 302 is formed on the outer side wall of the pressing block body 301, and a semi-circular threaded groove 303 is formed on the outer bottom wall of the pressing block body 301. The inner side wall of the groove 302 is engaged with the inner side walls of the first card slot 103 and the second card slot 203. A pressing screw 4 is used for threaded connection between the sector-shaped threaded groove 104 and the semi-circular threaded groove 303. By screwing the pressing screw 4 along the semi-circular threaded groove 303 and the sector-shaped threaded groove 104, the pressing block body 301 can be detachably connected to the iron core body 101, and thus adjacent iron core bodies 101 can be detachably connected, and the assembly of the permanent magnet motor rotor is completed.

[0023] Specifically, the number of the first card slots 103 and the second card slots 203 is two each. The two first card slots 103 are symmetrically distributed on the outer side wall of the iron core body 101, and the two second card slots 203 are symmetrically distributed on the outer side wall of the permanent magnet body 201. The number of the first card slots 103 and the second card slots 203 enables the pressing block body 301 to limit the position between the iron core body 101 and the permanent magnet body 201.

[0024] Specifically, the number of the grooves 302 is two, and the two grooves 302 are symmetrically distributed on the outer side wall of the pressing block body 301. The pressing block body 301 is located at the middle position between two adjacent iron core bodies 101. The number of the grooves 302 being two enables the pressing block body 301 to connect two adjacent iron core bodies 101.

[0025] Specifically, the number of the iron core body 101, the permanent magnet body 201, the pressing block body 301, and the pressing screw 4 is the same, and a plurality of the iron core bodies 101, the permanent magnet bodies 201, the pressing block bodies 301, and the pressing screws 4 can form a ring, and the axial permanent magnet motor rotor has its designed function by forming a ring with a plurality of the iron core bodies 101, the permanent magnet bodies 201, the pressing block bodies 301, and the pressing screws 4.

[0026] A method for using a wide-speed-range axial permanent magnet motor rotor includes the following steps: Step 1, insertion: Move the permanent magnet body 201 and align and insert the inner side wall of the side groove 202 with the inner side wall of the iron core groove 102, then slide the permanent magnet body 201 and completely embed the permanent magnet body 201 into the iron core body 101 to form a combination of the iron core body 101 and the permanent magnet body 201, and further make the first card slot 103 flush with the second card slot 203, so that the present invention has the function of quickly inserting between the permanent magnet body 201 and the iron core body 101. Step 2, assembly: Make the assembled combination of the iron core body 101 and the permanent magnet body 201 fit together to form a ring shape, then move the pressing block body 301 and align and slide the groove 302 with the first card slot 103 and the second card slot 203 to enable snap connection between the pressing block body 301 and the iron core body 101, and further limit between the iron core body 101 and the permanent magnet body 201, so that the present invention has the function of quickly assembling between the pressing block body 301 and the iron core body 101. Step 3, threaded connection: Screw the pressing screw 4 along the semi-circular thread groove 303 and the sector thread groove 104 to enable detachable connection between the pressing block body 301 and the iron core body 101, and further enable detachable connection between adjacent iron core bodies 101, thus completing the assembly of the permanent magnet motor rotor, so that the present invention has the function of quickly assembling among the iron core body 101, the permanent magnet body 201, and the pressing block body 301.

[0027] To better illustrate the use effect of the present invention, a specific embodiment of using the present invention is introduced below.

[0028] As Figure 6As shown, the cross-axis and direct-axis flux paths of the axial magnetic field permanent magnet motor proposed by the present invention are presented. The dashed line indicates the direct-axis (d-axis) magnetic circuit, while the solid line part represents the cross-axis (q-axis) magnetic circuit. The main path of the d-axis flux is as follows: starting from the permanent magnet body 201, it circumferentially circulates on the iron core body 101 to the next magnetic pole, then passes through the air gap along the axial direction to reach the stator, and then passes through the stator and the air gap to reach the other magnetic pole in the axial direction. Finally, it returns to the original magnetic pole along the iron core body 101 in the opposite direction through the air gap and the stator, thus forming a loop. The q-axis magnetic circuit is similar to the d-axis magnetic circuit, but only circulates between a pair of magnetic poles in the axial direction and has a 90° electrical angle phase difference from the d-axis magnetic circuit.

[0029] As Figure 7 and Figure 8 shown respectively are the cross-axis magnetic vector and direct-axis magnetic vector distribution diagrams. The magnetic path is basically the same as the above description, and the saturation of the d-axis magnetic vector is higher than that of the q-axis magnetic vector.

[0030] As Figure 9 shown, are the cross-axis and direct-axis inductance variation curves. It can be seen from Figure 9 this that the direct-axis inductance is approximately 864 μH, and the cross-axis inductance is approximately 709 μH. The direct-axis inductance is significantly greater than the cross-axis inductance, about 20%. The motor has an inverse salient pole structure, and the field weakening range is significantly improved.

[0031] In summary, the present invention realizes the function of fixing the permanent magnet body 201 in an embedded manner, avoiding damage to the permanent magnet body 201 due to axial magnetic pulling force and radial centrifugal force. Compared with the surface-mounted permanent magnet installation method, it reduces the gap between the iron core body 101 and the permanent magnet body 201, improves the rotor compactness, improves the product output accuracy, and uses the pressing block assembly 3 and the pressing screw 4 to fix the permanent magnet body 201 on the iron core body 101, which not only improves the rotor strength but also reduces the probability of permanent magnet damage. Moreover, the rotor carbon fiber winding process is omitted, saving raw materials, which makes the rotor assembly process more convenient, increases the product yield and stability. By using silicon steel sheet material to make the permanent magnet body 201, it not only reduces the permanent magnet consumption and the eddy current loss, but also improves the product operation efficiency and reduces the energy consumption, and also improves the D-axis inductance of the axial magnetic field permanent magnet motor, solving the shortcoming of poor field weakening ability of the existing axial magnetic field permanent magnet motor and broadening the application field of the axial magnetic field permanent magnet motor.

[0032] All the electronic components used in the present invention are common standard components or components known to those skilled in the art. Their structures and principles can be known to those skilled in the art through technical manuals or obtained through conventional experimental methods.

[0033] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A rotor of a wide-speed-range axial permanent magnet motor, comprising a plurality of iron core assemblies (1), characterized in that: A permanent magnet component (2) is arranged on the outer surface of the iron core component (1), and a pressing block component (3) is snap-connected between the outer side walls of multiple iron core components (1), wherein the iron core component (1) and the pressing block component (3) are detachably connected by a pressing screw (4); The iron core component (1) is used to support the permanent magnet component (2), the permanent magnet component (2) is used to fill the iron core component (1) and provide a constant magnetic field, the pressing block component (3) is used to limit the position of the permanent magnet component (2) and the iron core component (1) and cooperate with multiple iron core components (1) to form a ring, and the pressing screw (4) is used to detachably connect the iron core component (1) and the pressing block component (3).

2. The rotor of a wide-speed-range axial permanent magnet motor according to claim 1, characterized in that: The iron core component (1) includes an iron core body (101), an iron core groove (102) is formed on the upper surface of the iron core body (101), and a first clamping groove (103) is formed on the outer wall of the opening end of the iron core groove (102); A sector-shaped threaded groove (104) is formed on the outer side wall of the iron core body (101).

3. The rotor of a wide-speed-range axial permanent magnet motor according to claim 2, characterized in that: The permanent magnet component (2) includes a permanent magnet body (201), a side groove (202) is formed on the outer surface of the permanent magnet body (201), and a second clamping groove (203) is formed on the outer side wall of the permanent magnet body (201); The inner side wall of the side groove (202) is mutually wedged with the inner side wall of the iron core groove (102), and the grooving depths of the first clamping groove (103) and the second clamping groove (203) are the same; The permanent magnet body (201) is made of silicon steel sheet material.

4. A rotor of a wide-speed-range axial permanent magnet motor according to claim 3, characterized in that: The pressing block component (3) includes a pressing block body (301), a groove (302) is formed on the outer side wall of the pressing block body (301), and a semi-circular threaded groove (303) is formed on the outer wall of the bottom surface of the pressing block body (301); The inner side wall of the groove (302) is mutually wedged with the inner side walls of the first clamping groove (103) and the second clamping groove (203), and the sector-shaped threaded groove (104) and the semi-circular threaded groove (303) are threadedly connected by a pressing screw (4).

5. The rotor of a wide-speed-range axial permanent magnet motor according to claim 3, characterized in that: The numbers of the first clamping groove (103) and the second clamping groove (203) are both two, and the two first clamping grooves (103) are symmetrically distributed on the outer side wall of the iron core body (101), while the two second clamping grooves (203) are symmetrically distributed on the outer side wall of the permanent magnet body (201).

6. A rotor of a wide-speed-range axial permanent magnet motor according to claim 4, characterized in that: The number of the grooves (302) is two, and the two grooves (302) are symmetrically distributed on the outer side wall of the pressing block body (301), wherein the pressing block body (301) is located at the middle position between two adjacent iron core bodies (101).

7. A rotor of a wide-speed-range axial permanent magnet motor according to claim 4, characterized in that: The numbers of the iron core body (101), the permanent magnet body (201), the pressing block body (301) and the pressing screw (4) are the same, and multiple iron core bodies (101), permanent magnet bodies (201), pressing block bodies (301) and pressing screws (4) can form a ring.

8. A method for using a rotor of a wide-speed-range axial permanent magnet motor according to any one of claims 1-7, characterized in that Including the following steps: Step 1: Insertion. Move the permanent magnet body (201), align the inner wall of the side groove (202) with the inner wall of the iron core groove (102) and insert it. Then slide the permanent magnet body (201) and completely embed the permanent magnet body (201) inside the iron core body (101) to form a combination of the iron core body (101) and the permanent magnet body (201), so that the first card slot (103) can be flush with the second card slot (203). Step 2: Assembly. Press the assembled combination of the iron core body (101) and the permanent magnet body (201) together to form a circular ring. Then move the press block body (301), align the groove (302) with the first card slot (103) and the second card slot (203) and slide it in, so that the press block body (301) can be detachably connected to the iron core body (101), thereby limiting the position between the iron core body (101) and the permanent magnet body (201). Step 3: Threaded connection. Screw in the compression screw (4) along the semi-circular thread groove (303) and the sector thread groove (104), so that the press block body (301) can be detachably connected to the iron core body (101), and then the adjacent iron core bodies (101) can be detachably connected, thus completing the assembly of the permanent magnet motor rotor.

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