Deflection magnetic pole rotor punching sheet structure of permanent magnet synchronous motor and synchronous motor

Abstract

The utility model relates to a rotor punching sheet structure of a deflection magnetic pole of a permanent magnet synchronous motor, which comprises a rotor punching sheet (2), a permanent magnet groove structure is arranged on the rotor punching sheet (2), and a permanent magnet is arranged in the permanent magnet groove structure; the rotor punching sheet (2) is provided with a shaft hole (1), and a motor rotating shaft is arranged in the shaft hole (1). The device comprises two layers of permanent magnet grooves formed in the rotor punching sheet, the permanent magnets are embedded in the permanent magnet grooves, one layer is a V-shaped first permanent magnet groove, the other layer is a linear second permanent magnet groove, and the permanent magnet grooves are used for improving the output torque of the motor; besides, the axes of the permanent magnets in the first permanent magnet groove and the second permanent magnet groove deviate by a certain position and are used for adjusting the center of the whole magnetic pole of the rotor, so that the permanent magnet torque and the reluctance torque of the motor are maximized under the same current lead angle as much as possible, and the output torque of the motor is further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of motors, and specifically relates to a permanent magnet synchronous motor deflection pole rotor punching sheet structure and a synchronous motor. Background Art

[0002] Rare earth permanent magnet synchronous motors use rare earth permanent magnets to generate magnetic fields, and have the advantages of high power density, small size, high efficiency and simple control. In the prior art, there are two main ways to increase the electromagnetic torque of built-in permanent magnet synchronous motors: the first is to increase the number of rotor permanent magnet slots to optimize their size, further increase the dq axis inductance difference and thus increase the output of reluctance torque; this solution may reduce the mechanical strength of the rotor, and may cause the reluctance torque component to be too high, which will significantly reduce the power factor of the motor, thereby increasing the copper loss of the motor and reducing the efficiency of the motor; in addition, increasing the number of rotor permanent magnet slots may further increase the torque pulsation of the electromagnetic torque, thereby aggravating the vibration and noise level of the motor. The second is to deflect the permanent magnet poles, and its technical solution is relatively complex and difficult to implement. The motor dq axis is a coordinate system that describes the magnetic field characteristics of the motor, in which the d axis is perpendicular to the motor magnetic field and the q axis is in the same direction as the magnetic field. The d axis is usually called the direct axis, and the q axis is usually called the quadrature axis.

[0003] After searching, the applicant found that the Chinese patent document with publication number CN108667177A disclosed a high torque density asymmetric rotor structure on October 16, 2018, and the rotor structure is divided into a unidirectional offset asymmetric rotor structure and a bidirectional offset asymmetric rotor structure. Ferrite permanent magnets and NdFeB permanent magnets are distributed on the rotor, and the ferrite permanent magnets are distributed in a spoke shape. The NdFeB permanent magnet is in the shape of a "one" and is located on the outer circle of the rotor. The axial center of the NdFeB in the unidirectional offset structure is deflected counterclockwise by an angle of α from the center line of the adjacent ferrite; the NdFeB in the bidirectional offset structure rotates clockwise and counterclockwise by angles of β and γ, respectively.

[0004] While increasing the electromagnetic torque of the internal permanent magnet synchronous motor, this device will reduce the mechanical strength of the rotor, significantly reduce the efficiency of the motor and aggravate the vibration and noise level of the motor. Utility Model Content

[0005] The utility model aims to provide a permanent magnet synchronous motor deflection pole rotor punching structure and a synchronous motor which can realize the improvement of the electromagnetic torque of the built-in permanent magnet synchronous motor.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is: a permanent magnet synchronous motor deflection pole rotor punching structure, including a rotor punching, a permanent magnet slot structure is provided on the rotor punching, and a permanent magnet is provided in the permanent magnet slot structure; an axial hole is provided on the rotor punching, and the motor shaft is placed in the axial hole.

[0007] The permanent magnet slot structure includes a first permanent magnet slot and a second permanent magnet slot, wherein the second permanent magnet slot is arranged on a side of the first permanent magnet slot away from the shaft hole.

[0008] The first permanent magnet slot is a V-shaped structure, and the second permanent magnet slot is a straight-line structure.

[0009] The permanent magnets include a first permanent magnet disposed in the first permanent magnet slot and a second permanent magnet disposed in the second permanent magnet slot.

[0010] An offset position is provided between the axis of the first permanent magnet and the axis of the second permanent magnet.

[0011] As a solution, the second permanent magnet is a straight-line structure, and the first permanent magnet is an integrated V-shaped structure.

[0012] As another solution, the second permanent magnet is a straight-line structure, the first permanent magnet includes a plurality of permanent magnet blocks, the permanent magnet blocks are placed in the first permanent magnet slots, and gaps are provided along the central axis of the first permanent magnet slots.

[0013] The offset position between the axis of the first permanent magnet and the axis of the second permanent magnet ranges from -20%×τ to +20%×τ, where τ is the pole pitch.

[0014] The volume of the second permanent magnet is 30% to 50% of the volume of the first permanent magnet; the thickness of the first permanent magnet is greater than or equal to 3 mm, and the thickness of the second permanent magnet is greater than or equal to 4 mm; the permanent magnet slot structure is symmetrically arranged on the rotor punching sheet.

[0015] A permanent magnet synchronous motor comprises the deflection pole rotor punching structure.

[0016] The beneficial effects of this application are:

[0017] The permanent magnet slot structure arranged on the rotor punching sheet includes a first permanent magnet slot and a second permanent magnet slot; the first permanent magnet slot is close to the axial hole of the rotor punching sheet and is a V-shaped structure, which is beneficial to the magnetic field of the first permanent magnet to form a magnetic field concentration effect, effectively enhancing the permanent magnet torque output of the motor; the second permanent magnet slot is close to the outer edge of the rotor punching sheet and is a straight-line structure; it is convenient to adjust the installation position of the second permanent magnet in the second permanent magnet slot, realize the magnetic pole deflection to adjust the phase of the permanent magnet torque, and further improve the electromagnetic torque output of the motor.

[0018] The axis of the first permanent magnet and the axis of the second permanent magnet are offset by a certain position to adjust the overall magnetic pole center of the rotor, so that the permanent magnet torque and reluctance torque of the motor can achieve the maximum value at the same current lead angle as much as possible, thereby further improving the output torque of the motor.

[0019] The first permanent magnet and the second permanent magnet themselves do not have magnetic conductivity, and their relative magnetic permeability is close to that of air. Therefore, the first permanent magnet slot and the second permanent magnet slot themselves can form a magnetic barrier, change the dq axis magnetic conductivity, thereby changing the dq axis magnetic resistance, and further increase the permanent magnet torque, which can improve the electromagnetic torque of the motor.

[0020] The electromagnetic torque contains both permanent magnet torque components and reluctance torque components. The device uses two layers of permanent magnet excitation, namely the first permanent magnet and the second permanent magnet. Therefore, it can effectively take into account the power factor and efficiency of the motor while maintaining high electromagnetic torque output.

[0021] Therefore, the device can effectively improve the electromagnetic torque of the motor. The structure of the device will not reduce the mechanical strength of the rotor and will not cause the magnetic resistance torque component to be too high. It can effectively avoid the reduction of the power factor of the motor and the increase of the copper loss of the motor, and the reduction of the efficiency of the motor. The device will not increase the torque pulsation of the electromagnetic torque and effectively avoid the increase of vibration and noise of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The specific implementation of the utility model is further described in detail below in conjunction with the accompanying drawings, wherein:

[0023] Figure 1 It is a schematic diagram of the structure of the deflection pole rotor punching structure of the permanent magnet synchronous motor and the rotor punching structure of the synchronous motor.

[0024] Figure 2 This is the principle diagram of the deflection pole rotor punching structure of the permanent magnet synchronous motor and the superposition of the various components of the electromagnetic torque of the synchronous motor.

[0025] Figure 3 This is the torque waveform diagram of the finite element simulation of the deflected pole rotor punching structure and the undeflected pole rotor punching structure of this permanent magnet synchronous motor.

[0026] The marks in the above figure are:

[0027] Markings in the figure are: 1, shaft hole, 2, rotor punching, 3, first permanent magnet slot, 4, second permanent magnet slot, 5, first permanent magnet, 6, second permanent magnet. DETAILED DESCRIPTION

[0028] The following is a further detailed explanation of the specific implementation methods of the utility model through the description of the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the utility model and facilitating its implementation.

[0029] Figure 1 The permanent magnet synchronous motor deflection pole rotor punching structure and the synchronous motor shown include a rotor punching 2, on which a permanent magnet slot structure is provided, in which a permanent magnet is provided; the rotor punching 2 is provided with an axial hole 1, and the motor shaft is placed in the axial hole 1.

[0030] The synthetic electromagnetic torque of the built-in permanent magnet synchronous motor mainly includes two components: permanent magnet torque and reluctance torque. The permanent magnet torque is the torque generated by the interaction between the magnetic field generated by the permanent magnet and the magnetic field generated by the stator; the reluctance torque is the torque caused by the reluctance effect generated by the difference in reluctance between the dq axes of the rotor. Figure 2 In the figure, the permanent magnet torque and the reluctance torque achieve their maximum values ​​at different current lead angles. It can be seen that the maximum value of the synthetic electromagnetic torque can be adjusted by adjusting the phase of the maximum value of the permanent magnet torque or the reluctance torque.

[0031] The permanent magnet installed in the permanent magnet slot structure can adjust the center of the rotor's overall magnetic pole, so that the motor's permanent magnet torque and reluctance torque can achieve the maximum value at the same current lead angle as much as possible, thereby further improving the motor's output torque. This device can flexibly adjust the proportion of the permanent magnet torque and reluctance torque components in the motor's output electromagnetic torque, while ensuring the output torque of the permanent magnet synchronous motor, reducing the amount of permanent magnets used in the permanent magnet synchronous motor, improving the torque density and efficiency of the permanent magnet synchronous motor, and reducing processing and manufacturing costs. The rotor punching 2 is a disc structure with a central opening; the rotor punching 2 is a silicon steel sheet.

[0032] The permanent magnet slot structure includes a first permanent magnet slot 3 and a second permanent magnet slot 4, wherein the second permanent magnet slot 4 is arranged on a side of the first permanent magnet slot 3 away from the shaft hole 1. The first permanent magnet slot 3 is close to the shaft hole 1 of the rotor punching 2, and the second permanent magnet slot 4 is close to the outer edge of the rotor punching 2.

[0033] The first permanent magnet slot 3 is a V-shaped structure, and the second permanent magnet slot 4 is a straight-line structure. The first permanent magnet slot 3 is a V-shaped structure, which is conducive to the magnetic field of the first permanent magnet 5 installed in the first permanent magnet slot 3 to form a magnetic field concentration effect, effectively enhancing the permanent magnet torque output of the motor; the second permanent magnet slot 4 is a straight-line structure; it is convenient to adjust the installation position of the second permanent magnet 6 in the second permanent magnet slot 4, realize the magnetic pole deflection to adjust the phase of the permanent magnet torque, and further improve the electromagnetic torque output of the motor.

[0034] The permanent magnets include a first permanent magnet 5 disposed in a first permanent magnet slot 3 and a second permanent magnet 6 disposed in a second permanent magnet slot 4. The first permanent magnet 5 and the second permanent magnet 6 do not have magnetic conductivity, and their relative magnetic permeability is close to that of air. Therefore, the first permanent magnet slot 3 and the second permanent magnet slot 4 can form a magnetic barrier, change the dq axis magnetic conductivity, thereby changing the dq axis magnetic resistance, and further increase the permanent magnet torque, which can improve the electromagnetic torque of the motor.

[0035] An offset position is provided between the axis of the first permanent magnet 5 and the axis of the second permanent magnet 6. The axis of the first permanent magnet 5 and the axis of the second permanent magnet 6 are offset by a certain position to adjust the overall magnetic pole center of the rotor, so that the permanent magnet torque and the reluctance torque of the motor can obtain the maximum value at the same current lead angle as much as possible, thereby further improving the output torque of the motor.

[0036] As a solution, the second permanent magnet 6 is a straight-line structure, and the first permanent magnet 5 is an integrated V-shaped structure. The second permanent magnet 6 is a square permanent magnet block; the first permanent magnet 5 is a V-shaped permanent magnet block.

[0037] As another solution, the second permanent magnet 6 is a straight-line structure, the first permanent magnet 5 includes a plurality of permanent magnet blocks, the permanent magnet blocks are placed in the first permanent magnet slot 3, and gaps are provided along the central axis of the first permanent magnet slot 3. The first permanent magnet 5 includes a plurality of permanent magnet blocks, the plurality of permanent magnet blocks are symmetrically distributed in the slots on both sides of the first permanent magnet slot 3, and the plurality of permanent magnet blocks are provided with gaps along the central axis of the first permanent magnet slot 3.

[0038] The offset position between the axis of the first permanent magnet 5 and the axis of the second permanent magnet 6 ranges from -20%×τ to +20%×τ, where τ is the pole pitch. When the offset position between the axis of the first permanent magnet 5 and the axis of the second permanent magnet 6 is positive, the output torque of the motor in the forward direction is increased; when the offset position is negative, the output torque of the motor in the reverse direction is increased; in this embodiment, τ=62.8mm, the offset position of the permanent magnet axis is +5mm, which accounts for about +8% of the pole pitch, and can increase the output torque of the motor in the forward direction.

[0039] The volume of the second permanent magnet 6 is 30% to 50% of the volume of the first permanent magnet 5; the thickness of the first permanent magnet 5 is greater than or equal to 3mm, and the thickness of the second permanent magnet 6 is greater than or equal to 4mm. In this embodiment, the second permanent magnet 6 is 10mm long, 4.2mm wide, and 50.8mm in axial length. One second permanent magnet 6 is provided in each second permanent magnet slot 4, and its volume is 2133.6mm^2; the first permanent magnet 5 is 15mm long, 4.2mm wide, and 50.8mm in axial length. There are two first permanent magnets 5 in each first permanent magnet slot 3, and their total volume is 6400.8mm^2. The volume of the second permanent magnet 6 is 33.33% of the volume of the first permanent magnet 5; the thickness of the first permanent magnet 5 and the second permanent magnet 6 are both 4.2mm; it can effectively ensure the anti-demagnetization ability of the motor.

[0040] The permanent magnet slot structure is symmetrically arranged on the rotor punching sheet 2. The adjacent first permanent magnet slot 3 and the second permanent magnet slot 4 form a group to form a magnetic pole. The total number of permanent magnet slot groups is equal to the number of motor poles 2p, where p is the number of motor pole pairs; in this embodiment, the number of motor pole pairs p=8.

[0041] A permanent magnet synchronous motor comprises the deflection pole rotor punching structure.

[0042] like Figure 3 The finite element simulation torque waveform diagram of the deflected magnetic pole rotor punching structure and the undeflected magnetic pole rotor punching structure of the permanent magnet synchronous motor, the main structural parameters of the two structures remain unchanged, the main difference is that the axis of the first permanent magnet 5 and the axis of the second permanent magnet 6 of the undeflected magnetic pole rotor punching structure are aligned, that is, the second permanent magnet 6 is buried in the middle of the second permanent magnet slot 4. In this embodiment, the output torque of the undeflected reluctance rotor punching structure is 58.11Nm, and the output torque of the deflected reluctance rotor punching structure is 63.30Nm, which is about 8.93% higher than the former, and the torque improvement effect is more obvious.

[0043] The specific working process of the utility model is as follows:

[0044] A V-shaped first permanent magnet slot 3 and a straight-line second permanent magnet slot 4 are provided on the rotor punching 2; a first permanent magnet 5 is installed in the first permanent magnet slot 3, and a second permanent magnet 6 is installed in the second permanent magnet slot 4; the second permanent magnet 6 is moved so as to be offset from the axis of the first permanent magnet 5; and the rotor punching 2 is then installed on the motor shaft of the permanent magnet synchronous motor.

[0045] The above is an exemplary description of the utility model in conjunction with the accompanying drawings. Obviously, the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the utility model; or the above concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A permanent magnet synchronous motor deflection pole rotor punching structure, characterized in that: The invention comprises a rotor punching (2), wherein a permanent magnet slot structure is provided on the rotor punching (2), and a permanent magnet is provided in the permanent magnet slot structure; an axial hole (1) is provided on the rotor punching (2), and a motor shaft is placed in the axial hole (1); The permanent magnet slot structure comprises a first permanent magnet slot (3) and a second permanent magnet slot (4), wherein the second permanent magnet slot (4) is arranged on a side of the first permanent magnet slot (3) away from the shaft hole (1); The permanent magnets include a first permanent magnet (5) arranged in the first permanent magnet slot (3) and a second permanent magnet (6) arranged in the second permanent magnet slot (4); An offset position is provided between the axis of the first permanent magnet (5) and the axis of the second permanent magnet (6).

2. A permanent magnet synchronous motor deflection pole rotor punching structure according to claim 1, characterized in that: The first permanent magnet slot (3) is a V-shaped structure, and the second permanent magnet slot (4) is a straight-line structure.

3. A permanent magnet synchronous motor deflection pole rotor punching structure according to claim 2, characterized in that: The second permanent magnet (6) is a straight-line structure, and the first permanent magnet (5) is an integrated V-shaped structure.

4. A permanent magnet synchronous motor deflection pole rotor punching structure according to claim 2, characterized in that: The second permanent magnet (6) is of a straight-line structure; the first permanent magnet (5) comprises a plurality of permanent magnet blocks; the permanent magnet blocks are placed in the first permanent magnet slots (3), and gaps are provided along the central axis of the first permanent magnet slots (3).

5. A permanent magnet synchronous motor deflection pole rotor punching structure according to any one of claims 2 to 4, characterized in that: The offset position between the axis of the first permanent magnet (5) and the axis of the second permanent magnet (6) ranges from -20%×τ to +20%×τ, where τ is the pole pitch.

6. A permanent magnet synchronous motor deflection pole rotor punching structure according to claim 5, characterized in that: The volume of the second permanent magnet (6) is 30% to 50% of the volume of the first permanent magnet (5); the thickness of the first permanent magnet (5) is greater than or equal to 3 mm, and the thickness of the second permanent magnet (6) is greater than or equal to 4 mm; the permanent magnet slot structure is symmetrically arranged on the rotor punching (2).

7. A permanent magnet synchronous motor, characterized in that: It comprises the deflection magnetic pole rotor punching structure as described in any one of claims 1-6.

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