Rare-earth-free permanent magnet synchronous motor structure and design method

Abstract

The invention discloses a rare-earth-free permanent magnet synchronous motor structure and a design method, the rare-earth-free permanent magnet synchronous motor structure comprises a motor body and a rotor body arranged in the motor body, the rotor body is provided with a plurality of V-shaped magnetic steel grooves and a plurality of I-shaped magnetic steel grooves, and detachable magnetic steel is installed in the V-shaped magnetic steel grooves and the I-shaped magnetic steel grooves; the magnetic steel, the motor body and the rotor body are made of materials without rare earth metal, fluctuation of magnetic groove torque and load torque of the motor is reduced by designing the V-shaped grooves and adjusting inclination and length of the V-shaped grooves, power density is effectively improved, harmonic waves and NVH (noise vibration and harshness) of the motor are inhibited synchronously through the design methods, and the service life of the motor is prolonged. The motor has good efficiency, torque fluctuation and NVH performance under the full-rotation-speed working conditions of different permanent magnet structures, the rare-earth-free motor does not contain rare earth metal, and the manufacturing cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to a permanent magnet synchronous motor, and in particular to a rare earth-free permanent magnet synchronous motor structure and a design method. Background Art

[0002] Permanent magnet synchronous motors have many advantages such as high torque power, small size, high efficiency, and high speed. In the past decade, with the rapid development of power electronics and power semiconductors, permanent magnet synchronous motors have been used more and more widely, especially in automotive drive motors, where they have almost occupied the entire market share. The rotor of a permanent magnet synchronous motor uses permanent magnets as the excitation of the motor. Although it has the advantage of not consuming electrical energy, it also makes the motor design and the excitation cannot be changed.

[0003] However, as the market's cost and performance requirements for permanent magnet synchronous motors become increasingly refined and differentiated, it is difficult for a single motor to adapt to the diverse needs of the market. If each motor has to be newly developed according to market demand, it will take a long time, consume a lot of resources, and have high development costs, and naturally it will not be able to meet market demand. Rare earth-free permanent magnet synchronous motors have the same advantages as traditional rare earth permanent magnet synchronous motors, but traditional rare earth permanent magnets are very expensive, and the motors contain rare earth metals, which have high manufacturing costs.

[0004] Therefore, the existing permanent magnet synchronous motor needs to be further improved. Summary of the invention

[0005] The purpose of the present invention is to provide a rare earth-free permanent magnet synchronous motor structure, which can synchronously suppress motor harmonics and NVH through these design methods, so that the motor has good efficiency, torque fluctuation and NVH performance under full speed conditions of different permanent magnet structures to meet market demand.

[0006] A rare earth-free permanent magnet synchronous motor structure comprises a motor body and a rotor body arranged in the motor body, wherein the rotor body is arranged with a plurality of V-shaped magnetic steel grooves and a plurality of I-shaped magnetic steel grooves, and detachable magnetic steels are installed in the V-shaped magnetic steel grooves and the I-shaped magnetic steel grooves; the magnetic steels, the motor body and the rotor body are made of materials that do not contain rare earth metals.

[0007] Furthermore, the plurality of V-shaped magnetic steel grooves are evenly distributed around the central circumference of the rotor body.

[0008] Furthermore, the plurality of I-shaped magnetic steel slots are evenly distributed around the central circumference of the rotor body.

[0009] Furthermore, the number of the V-shaped magnetic steel slots is the same as the number of the I-shaped magnetic steel slots.

[0010] The multiple V-shaped magnetic steel grooves and the multiple I-shaped magnetic steel grooves are arranged alternately.

[0011] Furthermore, the V-shaped magnetic steel groove includes two oblique magnetic steel grooves which are symmetrically arranged with the radial direction of the cross section of the rotor body as the center line.

[0012] Further, the I-shaped magnetic steel slot is arranged along the radial direction of the cross section of the rotor body; The oblique magnetic steel slots are arranged obliquely relative to the radial direction of the cross section of the rotor body.

[0013] The purpose of the present invention is to provide a design method for a rare earth-free permanent magnet synchronous motor, which can design rotor structures with different performances according to different requirements of customers, thereby meeting more usage needs.

[0014] In order to achieve the above object, the present invention adopts the following scheme: The method comprises the steps of: designing the shape of the V-shaped magnetic steel slot according to processing requirements, thereby changing the torque and load torque of the motor magnetic steel slot; Step 2: According to the processing requirements, a deweighting hole is provided inside the I-shaped magnetic steel slot, so as to prevent magnetic leakage of the magnetic steel in the I-shaped magnetic steel slot and reduce the weight of the rotor body; Step three: according to the processing requirements, choose whether to install the magnetic steel in the I-shaped magnetic steel slot and whether to process the I-shaped magnetic steel slot.

[0015] Furthermore, the shape design in step 1 is to change the inner bevel angle and length of the V-shaped magnetic steel slot, so as to achieve a sinusoidal distribution of the magnetic poles and suppress motor harmonics and NVH; Furthermore, the shape design described in step one is to change the outer bevel angle and length of the V-shaped magnetic steel slot, thereby adjusting the motor reluctance torque, enhancing the motor torque and power, and being more conducive to the balance between motor platformization and flexibility in motor production and application requirements.

[0016] Furthermore, the shape of the deduplication hole is designed to be an isosceles trapezoid.

[0017] In summary, the present invention has the following beneficial effects compared with the prior art: The present invention solves the shortcomings existing in the existing permanent magnet synchronous motor. Through the structural setting of the present invention, it has the following advantages: by designing the V-groove and adjusting the inclination and length of the V-groove, the fluctuation of the motor magnetic slot torque and the load torque is reduced. The de-weighting hole is designed according to the demand to reduce the manufacturing materials and save the manufacturing cost, and the power density is also effectively improved. Through these design methods, the motor harmonics and NVH are synchronously suppressed, so that the motor has good efficiency, torque fluctuation and NVH performance under the full speed working conditions of different permanent magnet structures. The rare earth-free motor does not contain rare earth metals, and the manufacturing cost is greatly reduced. Moreover, in terms of work efficiency, the rare earth-free motor will be more efficient than the traditional motor. In addition, the rare earth-free motor does not contain rare earth metals, and the production process does not pollute the environment and waste resources, which conforms to the concept of modern environmental protection and sustainable development; at the same time, there are no problems such as economic security caused by rare earth metals, which is also more conducive to resource protection. And the structure is simple and easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a first structural schematic diagram of the present invention; Figure 2 This is a second structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] See also Figure 1-Figure 2 The present invention provides a rare earth-free permanent magnet synchronous motor structure, comprising a motor body and a rotor body 1 disposed in the motor body, wherein the rotor body 1 is provided with a plurality of V-shaped magnetic steel grooves 2 and a plurality of I-shaped magnetic steel grooves 3, wherein detachable magnetic steels 6 are installed in the V-shaped magnetic steel grooves 2 and the I-shaped magnetic steel grooves 3; the magnetic steels 6, the motor body and the rotor body 1 are made of materials that do not contain rare earth metals; A design method for a rare earth-free permanent magnet synchronous motor comprises the steps of: first, designing the shape of the V-shaped magnetic steel slot 2 according to processing requirements, thereby changing the torque and load torque of the motor magnetic steel slot; Step 2: According to the processing requirements, a deweighting hole 4 is provided inside the I-shaped magnetic steel slot 3, so as to prevent the magnetic steel 6 in the I-shaped magnetic steel slot 3 from leaking magnetic flux and reduce the weight of the rotor body 1; Step 3: According to the processing requirements, choose whether to install the magnetic steel 6 in the I-shaped magnetic steel slot 3 and whether to process the I-shaped magnetic steel slot 3; The shape design described in step 1 of the present invention is to change the inner bevel angle and length of the V-shaped magnetic steel slot 2, so as to achieve a sinusoidal distribution of the magnetic poles and suppress motor harmonics and NVH; The shape design described in step one of the present invention is to change the outer bevel angle and length of the V-shaped magnetic steel slot 2, so as to adjust the motor reluctance torque, enhance the motor torque and power, and be more conducive to the balance of motor production and application requirements for motor platformization and flexibility.

[0021] The shape of the deduplication hole 4 of the present invention is designed to be an isosceles trapezoid.

[0022] In the present invention, the plurality of V-shaped magnetic steel slots 2 are evenly distributed around the central circumference of the rotor body 1 .

[0023] In the present invention, the multiple I-shaped magnetic steel slots 3 are evenly distributed around the central circumference of the rotor body 1 .

[0024] The number of the V-shaped magnetic steel slots 2 of the present invention is the same as the number of the I-shaped magnetic steel slots 3 .

[0025] The multiple V-shaped magnetic steel grooves 2 and the multiple I-shaped magnetic steel grooves 3 are arranged alternately.

[0026] The V-shaped magnetic steel slot 2 of the present invention comprises two oblique magnetic steel slots 200 which are symmetrically arranged with the radial direction of the cross section of the rotor body 1 as the center line.

[0027] The I-shaped magnetic steel slot 3 of the present invention is arranged along the radial direction of the cross section of the rotor body 1; The oblique magnetic steel slots 200 are arranged obliquely relative to the radial direction of the cross section of the rotor body 1 .

[0028] A quadrilateral de-weighting hole 4 is designed at the bottom of the V-shaped magnetic steel slot 2, which is also a magnetic isolation slot. The shape can be modified according to the motor performance requirements to achieve the best performance.

[0029] The structural design can make the motor meet different performance requirements. The inner bevel of the V-shaped magnetic steel slot 2 belongs to the "modification" method of the magnetic steel slot. The sinusoidal distribution of the magnetic poles can be achieved through the bevel angle and length, thereby suppressing the motor harmonics and NVH. The outer bevel of the V-shaped magnetic steel slot 2 also belongs to the "reshaping" method of the magnetic steel slot. The bevel angle can be used to adjust the motor reluctance torque and enhance the motor torque and power. This is more conducive to the balance between motor platformization and flexibility in motor production and application needs.

[0030] The I-type magnetic steel slot 3 is designed with a magnetic isolation slot added to the corresponding bottom, which is designed to suppress the I-type magnetic steel slot 3 and also serves as a de-weighting hole 4. It suppresses the harmonics, torque fluctuations and NVH of the motor under high load.

[0031] This patent may also have another variation, which also falls within the scope of protection of this patent: no magnetic steel is installed in the I-shaped magnetic steel groove 3, or this magnetic steel groove is removed and only the V-shaped magnetic steel groove 2 is retained.

[0032] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A rare earth-free permanent magnet synchronous motor structure, comprising a motor body and a rotor body (1) arranged in the motor body, characterized in that: The rotor body (1) is provided with a plurality of V-shaped magnetic steel grooves (2) and a plurality of I-shaped magnetic steel grooves (3), and detachable magnetic steels (6) are installed in the V-shaped magnetic steel grooves (2) and the I-shaped magnetic steel grooves (3); the magnetic steels (6), the motor body and the rotor body (1) are made of materials that do not contain rare earth metals.

2. The rare earth-free permanent magnet synchronous motor structure according to claim 1, characterized in that: The plurality of V-shaped magnetic steel slots (2) are evenly distributed around the central circumference of the rotor body (1).

3. The rare earth-free permanent magnet synchronous motor structure according to claim 2, characterized in that: The plurality of I-shaped magnetic steel slots (3) are evenly distributed around the central circumference of the rotor body (1).

4. A rare earth-free permanent magnet synchronous motor structure according to any one of claims 1 to 3, characterized in that: The number of the V-shaped magnetic steel grooves (2) is the same as the number of the I-shaped magnetic steel grooves (3); The plurality of V-shaped magnetic steel grooves (2) and the plurality of I-shaped magnetic steel grooves (3) are arranged in an interlaced manner.

5. The rare earth-free permanent magnet synchronous motor structure according to claim 4, characterized in that: The V-shaped magnetic steel slot (2) comprises two oblique magnetic steel slots (200) which are arranged symmetrically with respect to the radial direction of the cross section of the rotor body (1) as the center line.

6. The rare earth-free permanent magnet synchronous motor structure according to claim 5, characterized in that: The I-shaped magnetic steel slot (3) is arranged along the radial direction of the cross section of the rotor body (1); The oblique magnetic steel slots (200) are arranged obliquely relative to the radial direction of the cross section of the rotor body (1).

7. A design method for a rare earth-free permanent magnet synchronous motor, characterized in that: A rare earth-free permanent magnet synchronous motor structure comprising any one of claims 1 to 6, The method comprises the steps of: designing the shape of the V-shaped magnetic steel slot (2) according to processing requirements, thereby changing the torque and load torque of the motor magnetic steel slot; Step 2: According to processing requirements, a deweighting hole (4) is provided inside the I-shaped magnetic steel slot (3), so as to prevent magnetic leakage of the magnetic steel (6) in the I-shaped magnetic steel slot (3) and reduce the weight of the rotor body (1); Step three: according to processing requirements, select whether to install the magnetic steel (6) in the I-shaped magnetic steel slot (3) and whether to process the I-shaped magnetic steel slot (3).

8. The design method of a rare earth-free permanent magnet synchronous motor according to claim 7, characterized in that: The shape design described in step 1 is to change the inner bevel angle and length of the V-shaped magnetic steel slot (2), thereby achieving a sinusoidal distribution of the magnetic poles and suppressing motor harmonics and NVH.

9. The design method of a rare earth-free permanent magnet synchronous motor according to claim 8, characterized in that: The shape design described in step 1 is to change the outer bevel angle and length of the V-shaped magnetic steel slot (2), thereby adjusting the motor reluctance torque, enhancing the motor torque and power, and being more conducive to balancing the motor production and application requirements of motor platformization and flexibility.

10. The design method of a rare earth-free permanent magnet synchronous motor according to claim 9, characterized in that: The shape of the de-weighting hole (4) is designed to be an isosceles trapezoid.

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