Inner rotor permanent magnet motor

Abstract

The invention provides an inner rotor permanent magnet motor, and relates to the technical field of permanent magnet motors, the inner rotor permanent magnet motor comprises a stator winding and a rotor core, a plurality of magnetic pole groups are fixed on the circumferential surface of the rotor core along the circumferential direction, a plurality of magnetic pole blocks with the same polarity are arranged in the magnetic pole groups, and the polarities of the magnetic pole blocks in adjacent magnetic pole groups are opposite; by adopting the radial segmentation design of the magnetic poles, the adjacent magnetic pole groups with opposite polarities comprise a plurality of magnetic pole blocks with the same polarity, so that the stress borne by the magnetic pole blocks in the high-speed rotating process is obviously reduced, and the breaking risk of the magnetic pole blocks is reduced; by arranging the small magnetic pole blocks, magnetizing is more uniform, magnetic flux loss is smaller, and more efficient magnetic field utilization is ensured.

Description

Technical Field

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

[0002] Electric motor, commonly known as "motor", is an electromagnetic device that realizes the conversion or transmission of electric energy according to the law of electromagnetic induction. With the progress of society, the requirements for motor power are gradually increasing. In the development process of high-power motors, it is usually required that the motors show higher reliability and efficiency under high speed and high load conditions. Due to its own characteristics, inner rotor motors are more suitable for occasions that require high speed and large torque.

[0003] However, in actual use, it is found that the permanent magnets in the traditional inner rotor motors often break, which seriously affects the normal operation of the motor.

[0004] Therefore, how to solve the problem of permanent magnet breakage is an important factor in ensuring the stable operation of the inner rotor permanent magnet motor. Summary of the invention

[0005] The purpose of the present invention is to provide an inner rotor permanent magnet motor to solve the problems existing in the prior art. The radial segmentation design of the magnetic poles is adopted so that adjacent magnetic pole groups with opposite polarities include multiple magnetic pole blocks with the same polarity, which significantly reduces the stress on the magnetic pole blocks during high-speed rotation and reduces the risk of breakage of the magnetic pole blocks.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] An inner rotor permanent magnet motor comprises a stator winding and a rotor core, wherein a plurality of magnetic pole groups are fixed on the circumferential surface of the rotor core in the circumferential direction, wherein the magnetic pole groups have a plurality of magnetic pole blocks with the same polarity, and the magnetic pole blocks in adjacent magnetic pole groups have opposite polarities.

[0008] As an embodiment, 2 to 5 magnetic pole blocks are provided in the magnetic pole group.

[0009] As one embodiment, three magnetic pole blocks are provided in the magnetic pole group.

[0010] As one embodiment, the inner circle length of the magnetic pole block is 22.22 mm, the outer circle length is 23.45 mm, and the width is 14 mm.

[0011] As an embodiment, slot wedges are fixed on the circumferential surface of the rotor core, and the magnetic pole blocks are embedded in the slot wedges and fixed.

[0012] As an implementation mode, the magnetic pole blocks are formed by stacking silicon steel sheets; the slot wedges and the rotor core are both made of silicon steel sheets.

[0013] As an embodiment, it further includes a carbon fiber wrapping layer, wherein the carbon fiber wrapping layer is wrapped around the outside of the magnetic pole group.

[0014] As an implementation manner, the stator winding includes a stator core and a coil winding arranged on the stator core, and the coil winding is a double-layered winding structure.

[0015] As an implementation manner, the phase difference of the windings in the double-layer stacked winding structure is 30°, the double-layer stacked winding structure has 12 pairs of poles, 144 slots, 24 parallel branches, and 39 series turns.

[0016] As an implementation manner, the rotor core is supported by a single-bearing cantilever structure.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] 1. The present invention adopts a radial segmented design of magnetic poles, so that adjacent magnetic pole groups with opposite polarities include multiple magnetic pole blocks with the same polarity, which significantly reduces the stress on the magnetic pole blocks during high-speed rotation and reduces the risk of breakage of the magnetic pole blocks;

[0019] 2. The present invention arranges small magnetic pole blocks to achieve more uniform magnetization and less magnetic flux leakage, thus ensuring more efficient magnetic field utilization;

[0020] 3. The structural setting of the segmented magnetic pole blocks in the magnetic pole group of the present invention increases the equivalent eddy resistance, reduces the eddy current effect, reduces the heat generated by the motor, thereby improving the operating efficiency. The application in high-power motors significantly improves the mechanical strength and reliability of the motor.

[0021] Other technical solutions of the present invention have the following technical effects compared with the prior art:

[0022] 1. The stator winding of the present invention adopts a full-pitch double-layer winding structure, which can more effectively utilize the magnetic field and generate a higher electromotive force; the double-layer winding method increases the copper filling rate in the stator slot and enhances the power density; at the same time, the 30° phase difference design forms a smooth magnetic field distribution between the three-phase currents, effectively reduces the torque pulsation, and improves the running stability of the motor; therefore, the present invention is particularly suitable for high-precision and low-noise application scenarios;

[0023] 2. In the present invention, the rotor core is supported by a single-bearing cantilever structure, and the other end of the rotor core remains free, which can reduce the centering accuracy requirements when installing the rotor core and avoid mechanical clamping and vibration problems caused by misalignment caused by dual-bearing support. During operation, the single-bearing cantilever structure provides the rotor with greater freedom, allowing large-diameter motors to remain stable under high-speed rotation. Therefore, the present invention uses a single-bearing cantilever structure to support the rotor core, which not only simplifies the installation and maintenance process of the motor, but also ensures the mechanical stability of the motor under high speed and heavy load conditions and the overall reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 A schematic diagram of a partial structure of an inner rotor permanent magnet motor in one embodiment of the present invention;

[0026] Figure 2 The figure is a schematic diagram of the wiring principle of the coil winding in one embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1. Stator winding; 2. Rotor core; 3. Pole block; 4. Slot wedge; 5. Carbon fiber wrapping layer. DETAILED DESCRIPTION

[0029] 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.

[0030] The purpose of the present invention is to provide an inner rotor permanent magnet motor to solve the problems existing in the prior art. The radial segmentation design of the magnetic poles is adopted so that adjacent magnetic pole groups with opposite polarities include multiple magnetic pole blocks with the same polarity, which significantly reduces the stress on the magnetic pole blocks during high-speed rotation and reduces the risk of breakage of the magnetic pole blocks.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 , Figure 2 As shown, this embodiment provides an inner rotor permanent magnet motor, including a stator winding 1 and a rotor core 2, a plurality of magnetic pole groups are fixed along the circumferential direction on the circumferential surface of the rotor core 2, the magnetic pole groups have a plurality of magnetic pole blocks 3 with the same polarity, and the magnetic pole blocks 3 in adjacent magnetic pole groups have opposite polarities.

[0033] During operation, the stator winding 1 is energized to generate a magnetic field, which generates an interaction force with the magnetic pole blocks 3 on the rotor core 2, causing the rotor core 2 to rotate. The inventors found that the rotor poles of traditional high-power motors are usually arranged in a whole block. In high-load applications, the rotor poles are prone to magnet rupture due to centrifugal force under high-speed rotation. Therefore, this embodiment adopts a radial segmented design of magnetic poles, so that adjacent magnetic pole groups with opposite polarities include multiple magnetic pole blocks 3 with the same polarity, which significantly reduces the stress on the magnetic pole blocks 3 during high-speed rotation and reduces the risk of breakage of the magnetic pole blocks 3. In addition, by arranging small pieces of magnetic pole blocks 3, the magnetization is more uniform, the magnetic flux leakage is less, and more efficient magnetic field utilization is ensured. In addition, the structural setting of the segmented magnetic pole blocks 3 in the magnetic pole group of this embodiment increases the equivalent eddy resistance, reduces the eddy current effect, and reduces the heat generated by the motor, thereby improving the operating efficiency. The application in high-power motors significantly improves the mechanical strength and reliability of the motor.

[0034] In the magnetic pole group of this embodiment, 2 to 5 magnetic pole blocks 3 are arranged; specifically, 3 magnetic pole blocks 3 are arranged, and the grooves between adjacent magnetic pole blocks 3 are fixed with clamps made of silicon steel sheets to improve the mechanical stability of the magnetic pole blocks 3; there are also clamps between adjacent magnetic pole blocks in different magnetic pole groups. In this embodiment, the inner circle length of the magnetic pole block 3 is 22.22mm, the outer circle length is 23.45mm, and the width (the width of the magnetic pole block 3 along the radial direction of the rotor) is 14mm. Of course, those skilled in the art can also design the size of the magnetic pole block 3 according to actual conditions.

[0035] In this embodiment, slot wedges 4 are fixed on the circumferential surface of the rotor core 2, and the magnetic pole blocks 3 are embedded in the slot wedges 4 and fixed, ensuring that the magnetic pole blocks 3 will not be displaced due to centrifugal force during high-speed rotation.

[0036] As an embodiment, the magnetic pole block 3 is made of laminated silicon steel sheets; the slot wedge 4 and the rotor core 2 are both made of silicon steel sheets. Specifically, the rotor core 2 is made of laminated silicon steel sheets with high magnetic permeability, and is mainly used to provide a magnetic circuit in the motor, so that the magnetic flux can be efficiently transmitted between the rotor core 2 and the stator winding 1, thereby generating electromagnetic torque.

[0037] In order to further avoid the problem of displacement or separation of the magnetic pole block 3 under the action of centrifugal force when rotating at high speed, the present embodiment also includes a carbon fiber wrapping layer 5. The carbon fiber wrapping layer 5 is made of high-strength and lightweight carbon fiber material. The carbon fiber wrapping layer 5 is wrapped around the outside of the magnetic pole group.

[0038] In this embodiment, the stator winding 1 includes a stator core and a coil winding arranged on the stator core, and the coil winding is a double-layered winding structure. Figure 2 As shown, the double-layer stacked winding structure adopts a full-pitch design, the phase difference of the winding is 30°, the double-layer stacked winding structure has 12 pairs of poles, 144 slots, 24 parallel branches, and 39 series turns. In traditional motor design, coil windings usually adopt single-layer or short-pitch windings, and the copper wire filling rate is limited, resulting in low power density. The full-pitch double-layer stacked winding structure adopted in this embodiment can more effectively utilize the magnetic field and generate a higher electromotive force; the double-layer stacking method increases the copper filling rate in the stator slot and enhances the power density; at the same time, the 30° phase difference design enables a smooth magnetic field distribution to be formed between the three-phase currents, effectively reducing torque pulsation and improving the running stability of the motor; therefore, this embodiment is particularly suitable for high-precision and low-noise application scenarios.

[0039] In this embodiment, the rotor core 2 is supported by a single-bearing cantilever structure, and the other end of the rotor core 2 remains free, which can reduce the requirements for the centering accuracy of the rotor core 2 during installation and avoid mechanical clamping and vibration problems caused by misalignment caused by dual-bearing support. During operation, the single-bearing cantilever structure provides the rotor with greater freedom, allowing large-diameter motors to remain stable under high-speed rotation. Therefore, this embodiment uses a single-bearing cantilever structure to support the rotor core 2, which not only simplifies the installation and maintenance process of the motor, but also ensures the mechanical stability of the motor under high speed and heavy load conditions and the overall reliability of the system.

[0040] Adaptive changes made according to actual needs are all within the protection scope of the present invention.

[0041] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An inner rotor permanent magnet motor, characterized in that: include: Stator winding; And a rotor core, a plurality of magnetic pole groups are fixed on the circumferential surface of the rotor core along the circumferential direction, the magnetic pole groups have a plurality of magnetic pole blocks with the same polarity, and the magnetic pole blocks in adjacent magnetic pole groups have opposite polarities.

2. The inner rotor permanent magnet motor according to claim 1, characterized in that: The magnetic pole group is provided with 2 to 5 magnetic pole blocks.

3. The inner rotor permanent magnet motor according to claim 2, characterized in that: Three magnetic pole blocks are arranged in the magnetic pole group.

4. The inner rotor permanent magnet motor according to claim 1, characterized in that: The inner circle length of the magnetic pole block is 22.22 mm, the outer circle length is 23.45 mm, and the width is 14 mm.

5. The inner rotor permanent magnet motor according to claim 1, characterized in that: A slot wedge is fixed on the circumferential surface of the rotor core, and the magnetic pole block is embedded in the slot wedge and fixed.

6. The inner rotor permanent magnet motor according to claim 5, characterized in that: The magnetic pole blocks are made of stacked silicon steel sheets; the slot wedges and the rotor core are both made of silicon steel sheets.

7. The inner rotor permanent magnet motor according to claim 1, characterized in that: It also includes a carbon fiber wrapping layer, wherein the carbon fiber wrapping layer is wrapped around the outside of the magnetic pole group.

8. The inner rotor permanent magnet motor according to claim 1, characterized in that: The stator winding comprises a stator core and a coil winding arranged on the stator core, and the coil winding is a double-layered winding structure.

9. The inner rotor permanent magnet motor according to claim 8, characterized in that: The phase difference of the windings in the double-layer stacked winding structure is 30°. The double-layer stacked winding structure has 12 pairs of poles, 144 slots, 24 parallel branches, and 39 series turns.

10. The inner rotor permanent magnet motor according to claim 1, characterized in that: The rotor core is supported by a single-bearing cantilever structure.

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