Motor rotor and permanent magnet synchronous motor

Abstract

The utility model discloses a motor rotor and a permanent magnet synchronous motor. The motor rotor comprises a rotor iron core; the at least two stages of permanent magnet assemblies comprise a plurality of radial magnetizing permanent magnets which are arranged on the circumferential outer side of the rotor iron core; the plurality of circumferential magnetizing permanent magnets are arranged on the circumferential outer side of the rotor core, and the circumferential magnetizing permanent magnets and the radial magnetizing permanent magnets are alternately arranged in the circumferential direction; wherein the axial end face of the radial magnetizing permanent magnet is provided with a first groove, the axial end face of the circumferential magnetizing permanent magnet is provided with a second groove, and the injection molding body is filled in the first groove and the second groove, so that the rotor iron core and the permanent magnet assembly are fixed together; the first groove and the second groove are at least partially staggered in the circumferential direction.

Description

Technical Field

[0001] This utility model relates to motor rotors and permanent magnet synchronous motors, and more specifically, to a motor rotor with higher strength and a permanent magnet synchronous motor including the motor rotor. Background Technology

[0002] The permanent magnets of a motor rotor are fixed to the iron core, causing it to rotate under the influence of the magnetic field and output torque and speed. However, for high-power permanent magnet synchronous motors, the fixing between the permanent magnets and the iron core may be unreliable, which can easily lead to the permanent magnets breaking or detaching during motor operation, causing safety hazards.

[0003] Therefore, it is hoped that a motor rotor can be proposed to overcome the shortcomings of the existing technology. Utility Model Content

[0004] According to a first aspect of the present invention, a motor rotor is provided, comprising: a rotor core; and at least two stages of permanent magnet assemblies arranged along the axial direction, the permanent magnet assemblies comprising: a plurality of radially magnetized permanent magnets arranged on the circumferential outer side of the rotor core, the radially magnetized permanent magnets generating a magnetic field in a generally radial direction; a plurality of circumferentially magnetized permanent magnets arranged on the circumferential outer side of the rotor core, the circumferentially magnetized permanent magnets generating a magnetic field in a generally circumferential direction, the circumferentially magnetized permanent magnets and the radially magnetized permanent magnets being arranged alternately in the circumferential direction; wherein, a first groove extending in the circumferential direction is formed on the axial end face of the radially magnetized permanent magnet, and a second groove extending in the circumferential direction is formed on the axial end face of the circumferentially magnetized permanent magnet, an injection molded body is filled in the rotor core and extends into the first and second grooves to fix the rotor core and the permanent magnet assemblies together; and wherein, the first groove and the second groove are at least partially offset in the circumferential direction.

[0005] According to this design, the injection-molded body filling the first and second grooves strengthens the bond between the permanent magnet assembly and the rotor core. Furthermore, because the first and second grooves are at least partially offset circumferentially, after the injection molding process, the injection-molded body forms an interlaced gear-like structure at the junction of the radially and circumferentially magnetized permanent magnets. This gear-like structure provides circumferential support to the permanent magnet assembly, thereby further enhancing the strength of the motor rotor.

[0006] In some designs, the first groove may be located outside the second groove in the radial direction.

[0007] In some designs, the first groove and the second groove can be connected in the circumferential direction.

[0008] According to this scheme, since the first groove and the second groove are connected in the circumferential direction, the first groove and the second groove can jointly form a receiving groove. The injection molded body is filled in the receiving groove to fix the rotor core and permanent magnet assembly together, which further improves the strength of the motor rotor.

[0009] In some embodiments, the radially magnetized permanent magnet may have a first flat surface, a first recess, and a first protrusion in sequence from the radially inner side to the radially outer side. The first recess is recessed relative to the first flat surface toward the axially inner side of the radially magnetized permanent magnet, and the first protrusion protrudes relative to the first flat surface toward the axially outer side of the radially magnetized permanent magnet. The first recess forms a first groove.

[0010] In some embodiments, the circumferentially magnetized permanent magnet may have a second flat surface, a second recess, and a second protrusion in sequence from the radially inner side to the radially outer side. The second recess is recessed relative to the second flat surface toward the axially inner side of the radially magnetized permanent magnet, and the second protrusion protrudes relative to the second flat surface toward the axially outer side of the radially magnetized permanent magnet. The second recess forms a second groove.

[0011] In some designs, the ratio of the width of the first groove to the width of the radially magnetized permanent magnet can be between 0.15 and 0.18.

[0012] In some designs, the ratio of the distance between the radial outer side of the first groove and the radial outer side of the radially magnetized permanent magnet to the width of the radially magnetized permanent magnet can be between 0.20 and 0.26.

[0013] In some designs, the ratio of the width of the second groove to the width of the circumferentially magnetized permanent magnet can be between 0.16 and 0.19.

[0014] In some designs, the ratio of the distance between the radial outer side of the second groove and the radial outer side of the circumferentially magnetized permanent magnet to the width of the circumferentially magnetized permanent magnet can be between 0.25 and 0.31.

[0015] According to a second aspect of the present invention, a permanent magnet synchronous motor is provided, comprising the motor rotor described in the first aspect of the present invention. Attached Figure Description

[0016] Figure 1 A schematic diagram of a motor rotor according to an embodiment of the present invention is shown;

[0017] Figure 2 yes Figure 1 A magnified view of a portion of the view;

[0018] Figure 3 A top view of a motor rotor according to an embodiment of the present invention is shown;

[0019] Figure 4It shows along Figure 3 A cross-sectional view taken from line AA in the diagram;

[0020] Figure 5 It shows along Figure 3 The cross-sectional view taken from line BB in the diagram.

[0021] Figure Labels

[0022] 100 motor rotor

[0023] 110 Rotor Core

[0024] 112 Iron core groove

[0025] 120 radially magnetized permanent magnet

[0026] 121 First flat surface

[0027] 122 First recess (first groove)

[0028] 123 First protrusion

[0029] 130 circumferentially magnetized permanent magnet

[0030] 131 Second flat surface

[0031] 132 Second concave portion (second groove)

[0032] 133 Second Protrusion

[0033] 140 injection molded body

[0034] 152 Axial Material Channel

[0035] 154 Radial Material Channels Detailed Implementation

[0036] To make the objectives, solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Unless otherwise stated, the terms used herein have their ordinary meanings in the art. The same reference numerals in the drawings represent the same parts.

[0037] For clarity, unless otherwise explicitly stated, the directional terms used herein have the following meanings: axial direction refers to the direction parallel to the axis of the motor rotor; radial direction refers to the direction passing through and perpendicular to the axis of the motor rotor; circumferential direction refers to the direction perpendicular to both the axial and radial directions. The width of a component refers to its dimension extending radially, and the length of a component refers to its dimension extending circumferentially.

[0038] like Figure 1As shown, the motor rotor 100 mainly includes a rotor core 110 and a rotor along the axial direction (i.e., Figure 1 The two-stage permanent magnet assembly (arranged vertically) drives the output shaft of the motor rotor 100 to rotate, thereby outputting torque and speed to the outside. Although Figure 1 The invention illustrates a two-stage permanent magnet assembly, but it should be understood that the invention is not intended to limit the number of stages of the permanent magnet assembly. The motor rotor 100 may also include three, four, or any other suitable number of permanent magnet assemblies along the axial direction.

[0039] During the manufacturing of the motor rotor 100, liquid injection molding material (e.g., BMC material) is injected into the gap between the rotor core 110 and the permanent magnet assembly. After cooling, the injection molding material solidifies to form an injection molded body 140 (e.g., ...). Figure 4 and Figure 5 As shown, the injection-molded body 140 forms a high-strength connector between the rotor core 110 and the permanent magnet assembly, which not only enhances the connection strength between adjacent permanent magnet assemblies, but also achieves a seamless and tight connection between the rotor core 110 and the permanent magnet assembly, thereby improving the overall structural integrity and performance stability of the motor rotor 100.

[0040] Each permanent magnet assembly includes multiple radially magnetized permanent magnets 120 and circumferentially magnetized permanent magnets 130, which are alternately arranged on the circumferential outer side of the rotor core 110. The radially magnetized permanent magnets 120 generate a magnetic field generally in the radial direction, and the circumferentially magnetized permanent magnets 130 generate a magnetic field generally in the circumferential direction. The radially magnetized permanent magnets 120 provide magnetic force for the rotation of the motor rotor 100, and the circumferentially magnetized permanent magnets 130 connect the magnetic fields generated by their two adjacent radially magnetized permanent magnets 120 to form a complete magnetic field line.

[0041] like Figure 2As shown, the radially magnetized permanent magnet 120 may sequentially have a first flat surface 121, a first recess 122, and a first protrusion 123 from the radially inner side to the radially outer side. The first recess 122 is recessed relative to the first flat surface 121 toward the axially inner side of the radially magnetized permanent magnet 120, and the first protrusion 123 protrudes relative to the first flat surface 121 toward the axially outer side of the radially magnetized permanent magnet 120. The first recess 122 forms a first groove. Similarly, the circumferentially magnetized permanent magnet 130 may sequentially have a second flat surface 131, a second recess 132, and a second protrusion 133 from the radially inner side to the radially outer side. The second recess 132 is recessed relative to the second flat surface 131 toward the axially inner side of the circumferentially magnetized permanent magnet 130, and the second protrusion 133 protrudes relative to the second flat surface 131 toward the axially outer side of the circumferentially magnetized permanent magnet 130. The second recess 132 forms a second groove. Furthermore, the radial inner wall of the circumferentially magnetized permanent magnet 130 fits into the core groove 112 of the rotor core 110 to facilitate positioning between the circumferentially magnetized permanent magnet 130 and the rotor core 110 during injection molding.

[0042] For two adjacent permanent magnet assemblies, the first grooves 122 of the two radially magnetized permanent magnets 120 together form a first intermediate receiving groove. Injection molding material is injected into the first intermediate receiving groove to fix the two adjacent radially magnetized permanent magnets 120 together. Similarly, the second grooves 132 of the two circumferentially magnetized permanent magnets 130 together form a second intermediate receiving groove. Injection molding material is injected into the second intermediate receiving groove to fix the two adjacent circumferentially magnetized permanent magnets 130 together. The presence of the first and second intermediate receiving grooves increases the bonding area of ​​the permanent magnet assembly, allowing for better filling of the gap between the rotor core 110 and the permanent magnet assembly during injection molding. This results in a stronger bond between the rotor core 110 and the permanent magnet assembly, which helps prevent the permanent magnet assembly from detaching due to vibration or centrifugal force during operation, thus improving the reliability and durability of the motor rotor 100.

[0043] like Figure 3 As shown, in the radial direction, the first groove 122 is located on the outer side relative to the second groove 132. In other words, the first groove 122 is farther from the central axis of the motor rotor 100 than the second groove 132 is. Furthermore, the first groove 122 and the second groove 132 partially overlap in the circumferential direction, allowing them to communicate. Because the first groove 122 and the second groove 132 are partially offset in the circumferential direction, after injection molding, the injection-molded parts 140 in the first groove 122 and the second groove 132 together form a gear-like structure. This gear-like structure provides circumferential support to the permanent magnet assembly, enabling the motor rotor 100 to withstand greater circumferential rotational forces, improving the overall strength of the motor rotor 100 and making it less prone to breakage.

[0044] Preferably, the radial outer wall of the radially magnetized permanent magnet 120 can be positioned further outward than the radial outer wall of the circumferentially magnetized permanent magnet 130. Specifically, the radial outer wall of the radially magnetized permanent magnet 120 can be positioned 0.2 mm further outward than the radial outer wall of the circumferentially magnetized permanent magnet 130. Because the radially magnetized permanent magnet 120 generates a magnetic field that provides the magnetic force for the rotation of the motor rotor 100, positioning the radially magnetized permanent magnet 120 further outward relative to the circumferentially magnetized permanent magnet 130 helps to improve the performance of the motor rotor 100.

[0045] The ratio of the width of the first groove 122 to the width of the radially magnetized permanent magnet 120 can be between 0.15 and 0.18, and the ratio of the width of the second groove 132 to the width of the circumferentially magnetized permanent magnet 130 can be between 0.16 and 0.19. If the widths of the first groove 122 and the second groove 132 are too large, it will result in material waste. Conversely, if the widths of the first groove 122 and the second groove 132 are too small, it will make the first groove 122 and the second groove 132 difficult to process.

[0046] The ratio of the distance between the radial outer side of the first groove 122 and the radial outer side of the radially magnetized permanent magnet 120 to the width of the radially magnetized permanent magnet 120 can be between 0.20 and 0.26, and the ratio of the distance between the radial outer side of the second groove 132 and the radial outer side of the circumferentially magnetized permanent magnet 130 to the width of the circumferentially magnetized permanent magnet 130 can be between 0.25 and 0.31. If the positions of the first groove 122 and the second groove 132 are too close to the outer side, the motor rotor 100 is prone to breakage during processing. Conversely, if the positions of the first groove 122 and the second groove 132 are too close to the inner side, the fixing effect of the injection molded body 140 will be poor.

[0047] Preferably, the length of the radially magnetized permanent magnet 120 can be greater than the length of the circumferentially magnetized permanent magnet 130. Because the radially magnetized permanent magnet 120 generates a magnetic field in the radial direction to provide magnetic force for the rotation of the motor rotor 100, the radially magnetized permanent magnet 120 is longer than the circumferentially magnetized permanent magnet 130, which helps to improve the performance of the motor rotor 100.

[0048] Specifically, the width of the first groove 122 can be 4 mm, the width of the first flat surface 121 can be 13.35 mm, and the width of the first protrusion 123 can be 5.9 mm; the width of the second groove 132 can be 4 mm, the width of the second flat surface 131 can be 10.76 mm, and the width of the second protrusion 133 can be 6.89 mm. Furthermore, the length of the radially magnetized permanent magnet 120 can be 26.9 mm, and the length of the circumferentially magnetized permanent magnet 130 can be 11.67 mm.

[0049] like Figure 4 and Figure 5 As shown, the motor rotor 100 may be provided with material channels for forming the injection-molded body 140, including an axial material channel 152 and a radial material channel 154. The axial material channel 152 extends in the axial direction, and the radial material channel 154 extends in the radial direction and communicates with a corresponding second groove 132. Alternatively, the radial material channel 154 may also communicate with a corresponding first groove 122. Furthermore, the radial material channel 154 may also communicate with a corresponding first groove 122 and a second groove 132, respectively. During injection molding, liquid injection material flows sequentially through the axial material channel 152 and the radial material channel 154, and then flows into the first groove 122 and / or the second groove 132 to fill the gap between the rotor core 110 and the permanent magnet assembly. Subsequently, the liquid injection material cools and solidifies to form the injection-molded body 140, thereby fixing the multi-stage permanent magnet assembly and the rotor core 110 together. Through the above injection molding method, the injection molded body 140 is fully filled in the gap between the rotor core 110 and the permanent magnet assembly, thereby making the rotor core 110 and the permanent magnet assembly more reliably fixed together. Under high-frequency vibration conditions, it can effectively prevent mutual collision between adjacent permanent magnet assemblies and reduce the risk of motor rotor 100 breaking.

[0050] This document describes in detail several exemplary embodiments of the present disclosure with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of the present disclosure, and various technical features and structures proposed in the present disclosure can be combined without exceeding the protection scope of the present disclosure, the protection scope of the present disclosure being determined by the appended claims.

Claims

1. A motor rotor, characterized in that, include: Rotor core; At least two stages of permanent magnet assemblies arranged along an axial direction, the permanent magnet assemblies comprising: - Multiple radially magnetized permanent magnets are arranged on the circumferential outer side of the rotor core, and the radially magnetized permanent magnets generate a magnetic field in a generally radial direction; - Multiple circumferentially magnetized permanent magnets are arranged on the circumferential outer side of the rotor core. The circumferentially magnetized permanent magnets generate a magnetic field in a generally circumferential direction. The circumferentially magnetized permanent magnets and the radially magnetized permanent magnets are arranged alternately in the circumferential direction. The radially magnetized permanent magnet has a first groove extending in the circumferential direction on its axial end face, and the circumferentially magnetized permanent magnet has a second groove extending in the circumferential direction on its axial end face. The injection molded body fills the rotor core and extends into the first and second grooves to fix the rotor core and the permanent magnet assembly together. Furthermore, the first groove and the second groove are at least partially offset in the circumferential direction.

2. The motor rotor according to claim 1, characterized in that, In the radial direction, the first groove is located outside the second groove.

3. The motor rotor according to claim 2, characterized in that, The first groove and the second groove are connected in the circumferential direction.

4. The motor rotor according to claim 3, characterized in that, The radially magnetized permanent magnet has a first flat surface, a first recess, and a first protrusion in sequence from the radially inner side to the radially outer side. The first recess is recessed relative to the first flat surface toward the axially inner side of the radially magnetized permanent magnet, and the first protrusion protrudes relative to the first flat surface toward the axially outer side of the radially magnetized permanent magnet. The first recess forms the first groove.

5. The motor rotor according to claim 3, characterized in that, The circumferentially magnetized permanent magnet has a second flat surface, a second recess, and a second protrusion in sequence from the radially inner side to the radially outer side. The second recess is recessed relative to the second flat surface toward the axially inner side of the circumferentially magnetized permanent magnet, and the second protrusion protrudes relative to the second flat surface toward the axially outer side of the circumferentially magnetized permanent magnet. The second recess forms the second groove.

6. The motor rotor according to claim 1, characterized in that, The ratio of the width of the first groove to the width of the radially magnetized permanent magnet is between 0.15 and 0.

18.

7. The motor rotor according to claim 1, characterized in that, The ratio of the distance between the radial outer side of the first groove and the radial outer side of the radially magnetized permanent magnet to the width of the radially magnetized permanent magnet is between 0.20 and 0.

26.

8. The motor rotor according to claim 1, characterized in that, The ratio of the width of the second groove to the width of the circumferentially magnetized permanent magnet is between 0.16 and 0.

19.

9. The motor rotor according to claim 1, characterized in that, The ratio of the distance between the radial outer side of the second groove and the radial outer side of the circumferentially magnetized permanent magnet to the width of the circumferentially magnetized permanent magnet is between 0.25 and 0.

31.

10. A permanent magnet synchronous motor, characterized in that, Includes an electric motor rotor according to any one of claims 1 to 9.

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