Rotor structure of motor for vehicle

Abstract

The utility model relates to a rotor structure of a motor for a vehicle, which comprises a rotor, the rotor comprises a magnetic conductive ring and a plurality of permanent magnets, each permanent magnet comprises a first arc-shaped surface, the first arc-shaped surfaces are contacted with the magnetic conductive ring, the radial width of the middle part of each permanent magnet is greater than the radial width of the two ends of each permanent magnet, and the first arc-shaped surfaces are in contact with the magnetic conductive ring. The width of the permanent magnet in the radial direction is gradually reduced from the middle to the two ends; the permanent magnet further comprises a second arc-shaped surface, and the second arc-shaped surface and the first arc-shaped surface are oppositely arranged. Compared with the prior art, the width of the permanent magnet in the radial direction is gradually reduced from the middle to the two ends, so that unequal air gaps are formed between the permanent magnet and the stator, the air gaps are non-uniform, namely the air gap in the center of the permanent magnet is smaller, the end part of the permanent magnet is larger, and the air gap magnetic flux density distribution under the permanent magnet is closer to sine waves; therefore, the cogging torque is reduced, and the vibration and noise of the motor are reduced.

Description

Technical Field

[0001] The utility model relates to a rotor structure of a motor for a vehicle, belonging to the technical field of motors for vehicles. Background Art

[0002] Since most of the surface-mounted permanent magnet structures of current motors for vehicles are straight-plate type, there is a relatively obvious cogging torque. Cogging torque is a periodic torque generated by the rotor and stator of a permanent magnet motor without power supply, which tends to adjust to the position with the minimum magnetic resistance. The harm of cogging torque is that it will cause torque pulsation of the permanent magnet motor, which will lead to speed fluctuation; torque pulsation will also cause vibration and noise of the motor. When the frequency of the pulsating torque is consistent with the resonant frequency of the armature current, resonance will occur, which will inevitably amplify the vibration and noise of the cogging torque; at the same time, it will seriously affect the positioning accuracy and servo performance of the motor, especially at low speed. Utility Model Content

[0003] The utility model aims to provide a rotor structure of a motor for a vehicle which can reduce the cogging torque in view of the shortcomings of the prior art.

[0004] To achieve the purpose, the technical solution adopted by the utility model is:

[0005] A rotor structure of a motor for a vehicle includes a rotor, wherein the rotor includes a magnetic ring and a plurality of permanent magnets, wherein the permanent magnet includes a first arcuate surface, wherein the first arcuate surface is in contact with the magnetic ring, wherein the radial width of the middle portion of the permanent magnet is greater than the radial width of the two ends of the permanent magnet, and the radial width of the permanent magnet decreases from the middle portion to the two ends.

[0006] As a further optimization of the above technical solution: the permanent magnet further includes a second arcuate surface, the second arcuate surface is arranged opposite to the first arcuate surface, and the radius of the second arcuate surface is the same as the radius of the first arcuate surface.

[0007] As a further optimization of the above technical solution: the permanent magnet further includes a third arcuate surface, the third arcuate surface is arranged opposite to the first arcuate surface, and the radius of the third arcuate surface is different from the radius of the first arcuate surface.

[0008] As a further optimization of the above technical solution: the permanent magnet also includes a plane, and the plane is arranged opposite to the first arc-shaped surface.

[0009] As a further optimization of the above technical solution: it also includes a stator, the rotor is sleeved on the outer circumference of the stator, a plurality of permanent magnets are evenly spaced and arranged on the inner circumference of the magnetic ring, and the first arc surface is in contact with the inner circumference of the magnetic ring.

[0010] Compared with the prior art, the radial width of the permanent magnet in the utility model decreases from the middle to the two ends, which forms unequal air gaps between the permanent magnet and the stator, making the air gap uneven, that is, the air gap at the center of the permanent magnet is smaller, and there is a larger air gap at the end of the permanent magnet, so that the air gap flux density distribution under the permanent magnet is closer to a sine wave, thereby reducing the cogging torque and reducing the vibration and noise of the motor; the radius of the second arc surface is the same as the radius of the first arc surface, so that there is no need to distinguish between the front and back sides when installing the permanent magnet, which greatly improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic cross-sectional structure diagram of the first embodiment of the utility model.

[0012] Figure 2 yes Figure 1 Schematic diagram of the enlarged structure at point A in the middle.

[0013] Figure 3 It is a schematic cross-sectional structure diagram of the second embodiment of the utility model.

[0014] Figure 4 yes Figure 3 Schematic diagram of the enlarged structure at point B in the middle. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and specific implementations. Figure 1-4 As shown, a rotor structure of a motor for a vehicle includes a rotor and a stator 3, and the rotor is sleeved on the outer circumference of the stator 3. The rotor includes a magnetic ring 2 and a plurality of permanent magnets 1, and the plurality of permanent magnets 1 are evenly spaced and arranged on the inner circumference of the magnetic ring 2. The permanent magnet 1 includes a first arcuate surface 11, which is formed by the side of the permanent magnet 1 protruding outward, and the first arcuate surface 11 is in contact with the inner circumference of the magnetic ring 2. The radial width of the middle part of the permanent magnet 1 is greater than the radial width of the two ends of the permanent magnet 1, and the radial width of the permanent magnet 1 decreases from the middle to the two ends, which makes unequal air gaps formed between the permanent magnet 1 and the stator, making the air gap uneven, that is, the air gap at the center of the permanent magnet 1 is smaller, and there is a larger air gap at the end of the permanent magnet 1, so that the air gap magnetic flux density distribution under the permanent magnet 1 is closer to a sine wave, thereby reducing the cogging torque and reducing the vibration and noise of the motor.

[0016] First embodiment:

[0017] like Figure 1 , 2As shown, the permanent magnet 1 also includes a second curved surface 12 formed by a convex shape, and the second curved surface 12 is arranged opposite to the first curved surface 11, and the radius of the second curved surface 12 is the same as the radius of the first curved surface 11; at this time, the magnetization direction of the permanent magnet 1 is from the first curved surface 11 to the second curved surface 12 or from the second curved surface 12 to the first curved surface 11, and there is no need to distinguish between the front and back sides when installing the permanent magnet 1, which greatly improves production efficiency. The permanent magnet 1 in the above structure is referred to as an equal-diameter semicircular permanent magnet. There is a gap between the second curved surface 12 and the outer peripheral surface of the stator 3.

[0018] Second embodiment:

[0019] like Figure 3 , 4 As shown, the permanent magnet 1 also includes a third arcuate surface 13 formed by convexity, the third arcuate surface 13 is arranged opposite to the first arcuate surface 11, and the radius of the third arcuate surface 13 is different from the radius of the first arcuate surface 11. The permanent magnet 1 in the above structure is referred to as an unequal semicircular permanent magnet. There is a gap between the third arcuate surface 13 and the outer peripheral surface of the stator 3.

[0020] Third embodiment:

[0021] The permanent magnet 1 also includes a plane, which is arranged opposite to the first arc-shaped surface. The permanent magnet 1 in the above structure is referred to as a semi-straight semi-circular permanent magnet. There is a gap between the plane and the outer peripheral surface of the stator 3.

[0022] The cogging torque simulation comparison data of the permanent magnets of each structure are as follows: the cogging torque of the straight plate permanent magnet in the prior art is 4.66Nm, the cogging torque of the equal diameter semicircular permanent magnet in the first embodiment is 2.214Nm, the cogging torque of the unequal semicircular permanent magnet in the second embodiment is 2.02Nm, and the cogging torque of the semi-straight semicircular permanent magnet in the third embodiment is 2.64Nm. It can be seen from the above data that the permanent magnet 1 in the utility model can significantly reduce the cogging torque, thereby reducing the vibration and noise of the motor; and according to the comparison of the operation of each physical prototype, the motor where the permanent magnet 1 in the utility model is located can obviously feel the reduction of vibration and noise.

[0023] The preferred specific embodiments of the present utility model are described in detail above. It should be understood that ordinary technicians in this field can make many modifications and changes based on the concept of the present utility model without creative work. Therefore, all technical solutions that can be obtained by technicians in this technical field based on the concept of the present utility model through logical analysis, reasoning or limited experiments on the basis of the existing technology should fall within the protection scope of the present utility model.

Claims

1. A rotor structure of a motor for a vehicle, comprising a rotor, wherein the rotor comprises a magnetic ring (2) and a plurality of permanent magnets (1), characterized in that The permanent magnet (1) comprises a first arcuate surface (11), the first arcuate surface (11) is in contact with the magnetic conductive ring (2), the radial width of the middle portion of the permanent magnet (1) is greater than the radial width of the two ends of the permanent magnet (1), and the radial width of the permanent magnet (1) decreases from the middle to the two ends.

2. The rotor structure of a motor for a vehicle according to claim 1, characterized in that The permanent magnet (1) further comprises a second arcuate surface (12), the second arcuate surface (12) being arranged opposite to the first arcuate surface (11), and the radius of the second arcuate surface (12) being the same as the radius of the first arcuate surface (11).

3. The rotor structure of a motor for a vehicle according to claim 1, characterized in that The permanent magnet (1) further comprises a third arcuate surface (13), the third arcuate surface (13) being arranged opposite to the first arcuate surface (11), and the radius of the third arcuate surface (13) being different from the radius of the first arcuate surface (11).

4. The rotor structure of a motor for a vehicle according to claim 1, characterized in that The permanent magnet (1) further comprises a plane, which is arranged opposite to the first arc-shaped surface.

5. A rotor structure of a motor for a vehicle according to any one of claims 1 to 4, characterized in that It also comprises a stator (3), the rotor is sleeved on the outer circumference of the stator (3), a plurality of permanent magnets (1) are evenly spaced and arranged on the inner circumference of the magnetic conductive ring (2), and the first arc surface (11) is in contact with the inner circumference of the magnetic conductive ring (2).

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