Rotor assembly and permanent magnet motor

Abstract

A rotor assembly and a permanent magnet motor, comprising a rotor body, permanent magnets and magnetic conductive parts, the rotor body is fixedly connected with the magnetic conductive parts, the permanent magnets comprise a first side wall, a second side wall, an outer end face and an inner end face, the permanent magnets are located between adjacent magnetic conductive parts, the first side wall and the second side wall are in contact with the adjacent magnetic conductive parts, and movement of the permanent magnets away from the center line of the rotor body is limited; the inner end face of the permanent magnet is in contact with the rotor body, movement of the permanent magnet towards the center line of the rotor body and rotation of the permanent magnet relative to the rotor body are limited; the outer end face is farther away from the bottom wall than the inner end face, and the width of the inner end face is greater than the width of the outer end face; leakage of magnetic flux generated by the magnetic bridge formed by the permanent magnets through the magnetic conductive parts is avoided, and the performance of the motor is improved.

Description

Technical Field

[0001] The present invention relates to the field of motors, and in particular to a permanent magnet motor and a rotor assembly. Background Art

[0002] The rotor assembly of the permanent magnet motor includes a built-in rotor structure. In this structure, the rotor assembly includes a rotor core and permanent magnets. The rotor core forms a receiving hole, and the permanent magnets are located in the receiving hole. In order to limit the radial position of the permanent magnets, the rotor core forms a continuous edge portion, and the edge portion forms a magnetic bridge, which causes magnetic flux leakage between adjacent permanent magnets through the magnetic bridge, affecting the performance of the motor. Summary of the Invention

[0003] The object of the present invention is to provide a rotor assembly and a permanent magnet motor, which can reduce magnetic leakage and improve motor performance.

[0004] The present application provides a rotor assembly, comprising a rotor body, a permanent magnet, and a magnetic conductive portion, wherein the rotor body is fixedly connected to the magnetic conductive portion, and the permanent magnet comprises a first side wall, a second side wall outer end surface, and an inner end surface. The permanent magnet is located between adjacent magnetic conductive portions, and the first side wall and the second side wall are in contact with adjacent magnetic conductive portions to limit the movement of the permanent magnet away from the center line of the rotor body; the inner end surface of the permanent magnet is in contact with the rotor body to limit the movement of the permanent magnet toward the center line of the rotor body and the rotation of the permanent magnet relative to the rotor body; the outer end surface is further away from the central axis of the rotor assembly than the inner end surface, and the width of the inner end surface is greater than the width of the outer end surface.

[0005] The present application also provides a permanent magnet motor, comprising a rotor assembly and a stator assembly, wherein the stator assembly is located at the outer periphery of the rotor assembly, and the rotor assembly is the rotor assembly described above.

[0006] The rotor assembly and permanent magnet motor of the present application include a rotor body, permanent magnets and a magnetic conductive part. The radial position of the permanent magnet is limited by the cooperation between the magnetic conductive part and the rotor body. Adjacent magnetic conductive parts are separated by permanent magnets to avoid leakage of magnetic flux between adjacent permanent magnets through the magnetic bridge, thereby improving the performance of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram of the three-dimensional structure of the first embodiment of the rotor assembly;

[0008] Figure 2 yes Figure 1 A schematic diagram of the front view of the middle rotor assembly;

[0009] Figure 3 yes Figure 1 A schematic diagram of the three-dimensional structure of the rotor body of the middle rotor assembly;

[0010] Figure 4 yes Figure 3 A schematic diagram of the front view of the middle rotor body;

[0011] Figure 5 yes Figure 1 A schematic diagram of the three-dimensional structure of the magnetic conductive part;

[0012] Figure 6 yes Figure 5 A schematic diagram of the front view of the magnetic conductive part;

[0013] Figure 7 yes Figure 1 A three-dimensional structural diagram of the permanent magnet;

[0014] Figure 8 yes Figure 7 A schematic diagram of the front view of the permanent magnet;

[0015] Figure 9 yes Figure 1 Schematic diagram of the combined structure of the rotor body and the shaft;

[0016] Figure 10 yes Figure 1 Schematic diagram of the combined structure of the rotor body, magnetic conductive part and shaft. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0018] The permanent magnet motor includes a rotor assembly and a stator assembly. The stator assembly is located on the outer periphery of the rotor assembly and includes a coil. When the permanent magnet motor is working, the current passing through the coil is controlled, thereby controlling the excitation magnetic field of the stator assembly, and the rotor assembly rotates under the action of the excitation magnetic field.

[0019] Combine Figure 1 and Figure 2, the rotor assembly 100 comprises a rotor body 10, permanent magnets 20, magnetic conductive parts 30 and a shaft 40, the rotor body 10, the permanent magnets 20, the magnetic conductive parts 30 and the shaft 40 are separately formed and then assembled into a whole; wherein the rotor body 10 is the installation reference, the shaft 40 is fixedly connected with the rotor body 10, in the embodiment, the rotor body 10 has a center hole 140, the shaft 40 passes through the center hole 140 and is fixedly connected with the rotor body 10, such as interference fit; the magnetic conductive parts 30 are assembled and limitingly connected with the rotor body 10, the permanent magnets 20 are located between adjacent magnetic conductive parts 30, the permanent magnets 20 contact the rotor body 10, the movement of the permanent magnets 20 towards the center direction of the rotor assembly is limited by the rotor body 10, the permanent magnets contact the adjacent magnetic conductive parts, the movement of the permanent magnets 20 away from the center direction of the rotor assembly is limited by the adjacent magnetic conductive parts, the magnetic conductive parts 30 are made of magnetic conductive material, such as laminated silicon steel sheets, in the embodiment, the number of the magnetic conductive parts 30 is four, which are divided into two groups, i.e. two first magnetic conductive parts and two second magnetic conductive parts, the first magnetic conductive parts and the second magnetic conductive parts are arranged at intervals, in the embodiment, the outer shapes of the first magnetic conductive parts and the second magnetic conductive parts are the same, of course, the outer shapes of the first magnetic conductive parts and the second magnetic conductive parts can be different according to design requirements; the adjacent magnetic conductive parts are spaced by the permanent magnets, avoiding the leakage magnetic of the adjacent permanent magnets through the magnetic bridge, improving the performance of the motor.

[0020] Referring to Figure 3 and Figure 4 , the rotor body 10 comprises a first protruding part 11, a second protruding part 13 and a receiving part, the receiving part 13 is located between the first protruding part 11 and the second protruding part 12, the receiving part 13 comprises a first side surface 131, a second side surface 132 and a bottom wall 133, the first side surface 131 is located on the side surface of the first protruding part, the second side surface 132 is located on the side surface of the second protruding part, the receiving part 13 has a receiving cavity 130, the first side surface 131, the second side surface 132 and the bottom wall 133 surround the receiving cavity 130; in the embodiment, the first side surface 131, the second side surface 132 and the bottom wall 133 are planes, the included angle between the first side surface 131 and the bottom wall 133 is greater than or equal to 90°, the included angle between the second side surface 132 and the bottom wall 133 is greater than or equal to 90°, so that the receiving cavity is rectangular or inverted trapezoidal, which is convenient for processing; the first protruding part and the second protruding part have the same structure, the rotor body comprises two first protruding parts and two second protruding parts, the first protruding parts and the second protruding parts are uniformly and spacedly arranged along the circumference of the rotor body, which is conducive to the stability of magnetic force driving; the material of the rotor body is non-magnetic conductive material, such as plastic material, which is conducive to reducing weight and manufacturing cost. The rotor body 10 has a center hole 140, the center line of the rotor body is the center line 141 of the center hole, the first side surface and the second side surface do not pass through the center line of the center hole of the rotor body; preventing the magnetic conductive part cooperating with the rotor body from being separated due to the effect of centrifugal force.

[0021] Referring to Figure 1 、 Figure 2 as well as Figure 10 The magnetic conductive part 30 includes a first magnetic conductive part 31 and a second magnetic conductive part 32. The first magnetic conductive part 31 is sleeved on the first protrusion 11, and the second magnetic conductive part 32 is sleeved on the second protrusion 12. The first magnetic conductive part 31 is matched with the first protrusion 11, and the second magnetic conductive part 32 is matched with the second protrusion 12. The permanent magnet 20 is located between the adjacent first magnetic conductive parts 31 and the second magnetic conductive part 32. The first side wall of the permanent magnet 20 contacts the corresponding part of the outer wall of the first magnetic conductive part 31, and the second side wall of the permanent magnet 20 contacts the corresponding part of the outer wall of the second magnetic conductive part 32. The movement of the permanent magnet 20 away from the center line of the rotor body 10 is limited by the cooperation of the first magnetic conductive part and the second magnetic conductive part. The permanent magnet 20 contacts the bottom wall 133, and the movement of the permanent magnet 20 toward the center line of the rotor body 10 is limited by the bottom wall 133.

[0022] The magnetic conductive portion includes stacked silicon steel sheets. The first magnetic conductive portion and the second magnetic conductive portion have the same structure. The first side surface 131 is arranged parallel to the corresponding portion of the inner side wall of the first magnetic conductive portion, and the second side surface 132 is arranged parallel to the corresponding portion of the inner side wall of the second magnetic conductive portion. The first side wall of the permanent magnet 30 is arranged parallel to the corresponding portion of the outer side wall of the first magnetic conductive portion, and the second side wall of the permanent magnet 30 is arranged parallel to the corresponding portion of the outer side wall of the second magnetic conductive portion. In this way, when assembling the rotor assembly, the magnetic conductive portion is inserted into the first protrusion or the second protrusion from one end of the rotor body, which facilitates assembly and can also prevent the magnetic conductive portion from being separated from the rotor body due to excessive centrifugal force. Taking the first magnetic conductive portion as an example, the structure of the magnetic conductive portion is introduced, see Figure 5 and Figure 6 The first magnetic conductive part 31 includes a first limiting part 311, a second limiting part 312 and a connecting part 313. The first limiting part 311 is located at one end of the connecting part 313, and the second limiting part 312 is located at the other end of the connecting part 313. The first limiting part 311 and the second limiting part are spaced apart, that is, there is a gap between the first limiting part and the second limiting part, that is, one end of the first limiting part and the second limiting part are connected by the connecting part, and there is a gap between the other ends of the first limiting part and the second limiting part; in this embodiment, the first limiting part and the second limiting part have the same structure. Taking the first limiting part as an example, the first limiting part forms a hook structure relative to the connecting part. The first limiting part 311 includes an inner side wall 3111 of the first magnetic conductive part and an outer side wall 3112 of the first magnetic conductive part. The inner side wall of the first magnetic conductive part is located on the inner side of the first limiting part, and the outer side wall of the first magnetic conductive part is located on the outer side of the first limiting part. Along the radial direction of the rotor assembly, the lengths of the first limiting portion and the second limiting portion located within the accommodating cavity are greater than or equal to the lengths of the first limiting portion and the second limiting portion located outside the accommodating cavity, which is beneficial to improving connection stability.

[0023] Combine Figure 1 、 Figure 2as well as Figure 4 The first protrusion 11 includes a first top 111, and the second protrusion 12 includes a second top 121. The first top 111 and the second top 121 are outer arc surfaces. The first magnetic conductive part includes a first connecting part 313, and the second magnetic conductive part includes a second connecting part. The first connecting part 313 and the second connecting part form an inner arc surface, and the outer arc surface is matched with the inner arc surface. In this embodiment, the outer wall of the first connecting part 313 is arc-shaped, and the outer wall of the second connecting part is arc-shaped. The outer wall of the first connecting part and the outer wall of the second connecting part are located on the same cylindrical surface, and the central axis of the cylindrical surface coincides with the center line of the center hole. To reduce the rotational resistance, they can also not coincide, and a plastic coating is formed on the periphery of the permanent magnet. The cylindrical surface formed after the plastic coating coincides with the center line 140.

[0024] See also Figure 7 and Figure 8 In this embodiment, the cross section of the permanent magnet 20 is trapezoidal, and the permanent magnet 20 includes a first side wall 21, a second side wall 22, an outer end face 23 and an inner end face 24. The first side wall 21, the second side wall 22, the outer end face 23 and the inner end face 24 are planar, and the angle between the inner end face 24 and the first side wall 21 is less than 90°, and the angle between the inner end face 24 and the second side wall 22 is less than 90°. The included angles of the second side walls can be the same, the included angles between the outer end face 23 and the first side wall 21 are greater than 90°, the included angles between the outer end face 23 and the second side wall 22 are greater than 90°, and the included angles between the outer end face 23 and the first side wall 21 and the included angles between the outer end face 23 and the second side wall 22 can be the same; such permanent magnets have good processing properties; of course, the above included angles can also be 90° to form a right-angled trapezoid; the assembly limit relationship of the permanent magnet has been discussed above and will not be repeated here.

[0025] It should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above embodiments, it should be understood by those skilled in the art that the present invention can still be modified or replaced by equivalents, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A rotor assembly, comprising a rotor body, a permanent magnet, and a magnetic conductive portion, wherein the rotor body is fixedly connected to the magnetic conductive portion, the permanent magnet comprising a first side wall, a second side wall, an outer end surface, and an inner end surface, the permanent magnet being located between adjacent magnetic conductive portions, the first side wall and the second side wall being in contact with adjacent magnetic conductive portions, thereby limiting movement of the permanent magnet away from a centerline of the rotor body; the inner end surface of the permanent magnet being in contact with the rotor body, thereby limiting movement of the permanent magnet toward the centerline of the rotor body and rotation of the permanent magnet relative to the rotor body; the outer end surface being further away from a central axis of the rotor assembly than the inner end surface, and the width of the inner end surface being greater than the width of the outer end surface; The rotor body includes a first protrusion, a second protrusion, and an accommodating portion, the accommodating portion being located between the first protrusion and the second protrusion, the accommodating portion including a first side surface and a second side surface, the first side surface being located on the first protrusion, and the second side surface being located on the second protrusion; the magnetic conductive portion includes a first magnetic conductive portion and a second magnetic conductive portion, the first magnetic conductive portion being sleeved on and form-fitted with the first protrusion, the second magnetic conductive portion being sleeved on and form-fitted with the second protrusion, and at least one of the first side surface and the second side surface not passing through the center line of the rotor body, so that the first magnetic conductive portion is radially limited by the first protrusion, and the second magnetic conductive portion is radially limited by the second protrusion; The side surfaces of the first protrusion are arranged to be converged in the direction close to the center line of the rotor body, the first side surface is arranged in parallel with the corresponding portion of the inner side wall of the first magnetic conductive portion, the second side surface is arranged in parallel with the corresponding portion of the inner side wall of the second magnetic conductive portion, the first side wall of the permanent magnet is arranged in parallel with the corresponding portion of the outer side wall of the first magnetic conductive portion, and the second side wall of the permanent magnet is arranged in parallel with the corresponding portion of the outer side wall of the second magnetic conductive portion.

2. The rotor assembly according to claim 1, wherein: The accommodating portion includes a bottom wall, the permanent magnet is located between the adjacent first magnetic conductive portion and the second magnetic conductive portion, the first side wall of the permanent magnet is matched with the first magnetic conductive portion, and the second side wall of the permanent magnet is matched with the second magnetic conductive portion, and the movement of the permanent magnet away from the center line of the rotor body is limited by the first magnetic conductive portion and the second magnetic conductive portion; the permanent magnet is in contact with the bottom wall, and the movement of the permanent magnet toward the center line of the rotor body is limited by the bottom wall.

3. The rotor assembly according to claim 2, wherein: The rotor body is made of non-magnetic material. The accommodating portion has an accommodating cavity formed on the rotor body. The first side surface, the second side surface and the bottom wall surround the accommodating cavity. The magnetic conductive portion includes stacked silicon steel sheets.

4. The rotor assembly according to claim 3, wherein: The rotor assembly includes a shaft, the rotor body has a center hole, the center line of the rotor body is the center line of the center hole, the shaft passes through the center hole and is fixedly connected to the rotor body, and neither the first side surface nor the second side surface passes through the center line of the center hole of the rotor body.

5. The rotor assembly according to any one of claims 1 to 4, characterized in that: The bottom wall of the accommodating portion is a planar structure, the angle between the first side surface and the bottom wall is greater than or equal to 90°, and the angle between the second side surface and the bottom wall is greater than or equal to 90°.

6. The rotor assembly according to claim 5, characterized in that: The cross-section of the permanent magnet is trapezoidal, the inner end face and the outer end face are both planar, the angle between the inner end face and the first side wall of the permanent magnet is less than 90°, the angle between the inner end face and the second side wall of the permanent magnet is less than 90°, the angle between the outer end face and the first side wall of the permanent magnet is greater than 90°, and the angle between the outer end face and the second side wall of the permanent magnet is greater than 90°.

7. The rotor assembly according to claim 6, wherein: The first raised portion includes a first top portion, the second raised portion includes a second top portion, the first top portion and the second top portion are outer arc surfaces, the first magnetic conductive portion includes a first connecting portion, the second magnetic conductive portion includes a second connecting portion, the first connecting portion and the second connecting portion are inner arc surfaces, and the outer arc surface is matched with the inner arc surface.

8. The rotor assembly according to claim 7, wherein: The outer wall of the first connecting part is in an arc shape, the outer wall of the second connecting part is in an arc shape, the outer wall of the first connecting part and the outer wall of the second connecting part are located on the same cylindrical surface, and the central axis of the cylindrical surface coincides with the center line of the central hole.

9. The rotor assembly according to claim 8, characterized in that: Along the radial direction of the rotor assembly, the length of a portion of the magnetic conductive portion located within the accommodating cavity is greater than or equal to the length of a portion of the magnetic conductive portion located outside the accommodating cavity.

10. A permanent magnet motor comprising a rotor assembly and a stator assembly, wherein the stator assembly is located at the outer periphery of the rotor assembly, and the rotor assembly is the rotor assembly according to any one of claims 1 to 9.

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