A built-in permanent magnet motor rotor structure

Abstract

The application discloses a built-in permanent magnet motor rotor structure, which comprises a rotating shaft and a plurality of rotor magnetic pole units, a permanent magnet slot is arranged in the rotor magnetic pole unit to separate the rotor magnetic pole unit into a plurality of layers of magnetic conductive cores, the plurality of outer magnetic bridges and inner magnetic bridges are connected into a whole, the inner magnetic bridge separates the permanent magnet slot into asymmetric left permanent magnet slots and right permanent magnet slots, rectangular block-shaped right permanent magnets and left permanent magnets are respectively arranged in the left permanent magnet slots and the right permanent magnet slots, the oblique included angle formed by the center line of the right permanent magnet of the same layer and the rotor D shaft is different from the left included angle, the inner and outer magnetic isolation bridges contain non-magnetic conductive magnetic isolation blocks, and magnetic lines of force cannot pass through the closed loop formed by the inner magnetic bridge and the outer magnetic bridge; the application solves the problems that the rotor magnetic bridge area magnetic leakage leads to low output torque, the magnetic bridge stress is too large to further improve the rotating speed, the permanent magnet torque and the magnetic resistance torque current angle are different by 45 DEG, the output comprehensive torque is low, and the motor power density is low.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of permanent magnet motor, and particularly relates to a built-in permanent magnet motor rotor structure. BACKGROUND

[0002] At present, the method for reducing inter-pole leakage magnetic of the built-in permanent magnet motor rotor is to reduce the thickness of the rotor magnetic bridge and improve the magnetic field saturation of the rotor magnetic bridge.

[0003] However, the method will increase the stress of the rotor magnetic bridge and reduce the strength, thereby restricting the increase of the motor rotating speed, and on the other hand, part of the magnetic flux still passes through the magnetic bridge, that is, part of the leakage magnetic still exists, and the increase of the magnetic field saturation degree will also bring larger harmonic magnetic density, which is not conducive to the increase of the motor power density and torque density.

[0004] Meanwhile, the built-in permanent magnet motor rotor comprises permanent magnet torque and magnetic resistance torque, for the motor with a symmetrical rotor structure, the current angle reaching the maximum of the permanent magnet torque and the magnetic resistance torque is different by nearly 45 degrees, which leads to the decrease of the utilization of the two, and is not conducive to the comprehensive improvement of the motor torque. SUMMARY

[0005] The application aims at providing a built-in permanent magnet motor rotor structure to realize the increase of the motor output torque and rotating speed according to the defects of the prior art.

[0006] In order to realize the above-mentioned purpose, the application adopts the technical scheme that a built-in permanent magnet motor rotor structure comprises a rotating shaft and a plurality of rotor magnetic pole units symmetrically surrounding the rotating shaft, the number of the rotor magnetic pole units is equal to the number of the motor poles, a layer or multiple layers of permanent magnet grooves are arranged in the rotor magnetic pole units, the permanent magnet grooves separate the rotor magnetic pole units into multiple layers of magnetic conductive cores, the magnetic conductive cores are connected into a whole by a plurality of outer magnetic bridges and inner magnetic bridges, the inner magnetic bridges separate the permanent magnet grooves into asymmetric left permanent magnet grooves and right permanent magnet grooves, rectangular block-shaped right permanent magnets and left permanent magnets are respectively arranged in the left permanent magnet grooves and the right permanent magnet grooves, the oblique included angle formed by the center line of the right permanent magnet of the same layer and the rotor D shaft is different from the oblique included angle formed by the center line of the left permanent magnet and the rotor D shaft, that is, alpha1 not equal to beta1, alpha2 not equal to beta2, alpha3 not equal to beta3, …, alpha n not equal to beta n, n represents the number of the permanent magnet layers, the inner magnetic bridge is composed of the magnetic conductive cores of adjacent layers and one or more inner magnetic separation blocks which do not conduct magnetic, the outer magnetic bridge is composed of the magnetic conductive cores and one or more outer magnetic separation blocks which do not conduct magnetic and are spaced and connected in series, and the magnetic force lines cannot pass through the closed loop formed by the inner magnetic bridge and the outer magnetic bridge.

[0007] The permanent magnet slot of the built-in permanent magnet motor rotor structure has three layers, the magnetic conducting core comprises a first layer of magnetic conducting core, a second layer of magnetic conducting core, a third layer of magnetic conducting core and a fourth layer of magnetic conducting core, the left permanent magnet slot and the right permanent magnet slot are connected into a U-shaped type through the middle slot.

[0008] The permanent magnet slot of the built-in permanent magnet motor rotor structure has one layer, the magnetic conducting core comprises a first layer of magnetic conducting core and a second layer of magnetic conducting core, the left permanent magnet slot and the right permanent magnet slot are connected into a V-shaped type, the V-shaped permanent magnet slot is separated by an inner magnetic bridge, and the inclination angles of the right permanent magnet slot and the left permanent magnet slot are different.

[0009] Further, the rotor magnetic pole unit is four.

[0010] The number of the outer magnetic isolation blocks in each outer magnetic bridge is same as the number of layers of the permanent magnet slot.

[0011] The number of the inner magnetic isolation blocks in each inner magnetic bridge is one, and the width of the inner magnetic isolation block is equal to the width of the inner magnetic bridge.

[0012] The inner magnetic isolation block, the outer magnetic isolation block, the inner magnetic bridge, the outer magnetic bridge and the magnetic conducting core form an integral whole.

[0013] Further, the inner magnetic isolation block and the outer magnetic isolation block are subjected to nitriding treatment, so that the inner and outer magnetic isolation blocks are not magnetically conductive.

[0014] The built-in permanent magnet motor rotor structure has the following advantages:

[0015] 1. The outer magnetic isolation block and the inner magnetic isolation block are arranged in the outer magnetic bridge and the inner magnetic bridge of the built-in permanent magnet motor rotor structure, the magnetic flux line closing loop on the rotor side is blocked, the magnetic leakage on the rotor side is greatly reduced, the air gap magnetic field is enhanced, and the output torque of the motor rotor is improved.

[0016] 2. The magnetic bridge part does not need to consider the magnetic leakage problem, and the thickness design only needs to consider the mechanical strength, so that the strength of the built-in permanent magnet motor rotor structure is improved, the motor speed is further improved, and the power density of the motor is improved.

[0017] 3. The left and right permanent magnet slots in the same layer of the rotor magnetic pole unit are asymmetrically designed in position inclination angle, so that the current angles reaching the maximum values of the permanent magnet torque and the magnetic resistance torque components are closer, and the output torque is comprehensively improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of embodiment 1 of the application;

[0019] Figure 2 is a structural schematic diagram of embodiment 2 of the present application.

[0020] The reference signs are as follows: 1 - inner magnetic isolation block, 2 - inner magnetic bridge, 3 - first layer of magnetic core, 4 - second layer of magnetic core, 5 - third layer of magnetic core, 6 - fourth layer of magnetic core, 7 - outer magnetic isolation block, 8 - outer magnetic bridge, 9 - right side permanent magnet slot, 10 - left side permanent magnet slot, 11 - right side permanent magnet, 12 - left side permanent magnet, 13 - rotating shaft, 14 - rotor magnetic pole unit, 15 - permanent magnet slot, 16 - permanent magnet. DETAILED DESCRIPTION

[0021] The present application is further described below in conjunction with the drawings and examples. Example 1

[0022] As shown in the drawings, Figure 1 a motor rotor structure disclosed by the present application, the motor rotor is an inner built-in permanent magnet motor rotor structure, which is composed of a rotating shaft 13 and a plurality of rotationally symmetrical rotor magnetic pole units 14, the number of the rotor magnetic pole units 14 is equal to the number of poles of the motor, three layers of permanent magnet slots 15 are provided inside the rotor magnetic pole units 14, the permanent magnet slots 15 can be U-shaped, the permanent magnet slots 15 divide the rotor magnetic pole units 14 into four layers of magnetic cores, i.e. a first layer of magnetic core 3, a second layer of magnetic core 4, a third layer of magnetic core 5 and a fourth layer of magnetic core 6, an outer magnetic bridge 8 and an inner magnetic bridge 2 connect the multiple layers of magnetic cores to form a whole, the inner magnetic bridge 2 divides the permanent magnet slots 15 into asymmetric right side permanent magnet slots 9 and left side permanent magnet slots 10, rectangular permanent magnets 16 are respectively placed in the permanent magnet slots 15, rectangular block-shaped right side permanent magnets 11 and left side permanent magnets 12 are respectively placed in the right side permanent magnet slots 9 and the left side permanent magnet slots 10, the oblique included angle formed by the center line of the right side permanent magnets 11 and the D-axis of the rotor is not equal to the oblique included angle formed by the center line of the left side permanent magnets 12 and the D-axis of the rotor in the same layer, i.e. α1≠β1, α2≠β2, α3≠β3, …, αn≠βn, n represents the number of layers of permanent magnets. The inner magnetic bridge 2 is composed of adjacent layers of magnetic cores and inner magnetic isolation blocks 1 which do not conduct magnetic flux, the outer magnetic bridge 8 is composed of magnetic cores and a plurality of outer magnetic isolation blocks 7 which do not conduct magnetic flux and are connected in series, and the magnetic flux cannot form a closed loop through the inner magnetic bridge 2 and the outer magnetic bridge 8.

[0023] In each outer magnetic bridge 8, the outer magnetic isolation blocks 7 are located between the adjacent layers of the magnetic conductive core, and the number of the outer magnetic isolation blocks 7 is the same as the number of the layers of the permanent magnet slot 15. In each inner magnetic bridge 2, when the number of the inner magnetic isolation blocks 1 is one, the width of the inner magnetic isolation block 1 is equal to the width of the inner magnetic bridge 2. The inner magnetic isolation block 1, the outer magnetic isolation block 7, the inner magnetic bridge 2, the outer magnetic bridge 8 and the magnetic conductive core are an integral whole, and the implementation is that the rotor of the motor adopts a double-phase magnetic material, and the nitriding treatment is performed in the area of the inner magnetic isolation block 1 and the outer magnetic isolation block 7, so that the area of the inner and outer magnetic isolation blocks is not magnetically conductive. Embodiment 2

[0024] Figure 2 Another embodiment of the motor rotor of the application is shown, and the difference between the embodiment and the embodiment 1 is that the number of the rotor magnetic pole units 14 in the embodiment is four, that is, the pole number of the motor rotor is four, the permanent magnet slot 15 has only one layer, the magnetic conductive core includes the first layer of the magnetic conductive core 3 and the second layer of the magnetic conductive core 4, the left permanent magnet slot 10 and the right permanent magnet slot 9 are connected in a V shape, the inner magnetic bridge 2 separates the V-shaped permanent magnet slot 15, and the inclination angles of the right permanent magnet slot 9 and the left permanent magnet slot 10 are different.

[0025] Compared with the background art, the application solves the problems that the current built-in permanent magnet motor rotor magnetic bridge area magnetic leakage leads to low output torque, the magnetic bridge stress is too large to further improve the rotation speed, the permanent magnet torque and the reluctance torque current angle difference is 45°, which leads to low output comprehensive torque, and further leads to low motor power density, and can be applied to the field of permanent magnet motors.

[0026] The above is only as a specific embodiment of the application, but the scope of the application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the scope disclosed by the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. An interior permanent magnet motor rotor structure comprising a rotation shaft (13) and a plurality of rotor pole units (14) symmetrically surrounding the rotation shaft (13), characterized in that: The number of the rotor magnetic pole units (14) is equal to the number of motor poles, a layer or multiple layers of permanent magnet grooves (15) are arranged in the rotor magnetic pole units (14), the permanent magnet grooves (15) divide the rotor magnetic pole units (14) into multiple layers of magnetic conductive cores, the magnetic conductive cores are connected into a whole by multiple outer magnetic bridges (8) and inner magnetic bridges (2), the inner magnetic bridges (2) divide the permanent magnet grooves (15) into left permanent magnet grooves (10) and right permanent magnet grooves (9), the left permanent magnet grooves (10) and the right permanent magnet grooves (9) are respectively arranged with right permanent magnets (11) and left permanent magnets (12), the center line of the right permanent magnets (11) in the same layer and the D-axis of the rotor form an angle different from the center line of the left permanent magnets (12) and the D-axis of the rotor, the inner magnetic bridges (2) are composed of the magnetic conductive cores of adjacent layers and non-magnetic inner magnetic blocks (1) in series, and the outer magnetic bridges (8) are composed of the magnetic conductive cores and non-magnetic outer magnetic blocks (7) in series.

2. An interior permanent magnet motor rotor structure according to claim 1, characterized in that, The permanent magnet grooves (15) have three layers, the magnetic conductive cores include first layer magnetic conductive cores (3), second layer magnetic conductive cores (4), third layer magnetic conductive cores (5) and fourth layer magnetic conductive cores (6), and the left permanent magnet grooves (10) and the right permanent magnet grooves (9) are connected into a U-shaped type through intermediate grooves.

3. The rotor structure of an interior permanent magnet motor according to claim 1, wherein The permanent magnet grooves (15) have one layer, the magnetic conductive cores include first layer magnetic conductive cores (3) and second layer magnetic conductive cores (4), and the left permanent magnet grooves (10) and the right permanent magnet grooves (9) are connected into a V-shaped type.

4. An interior permanent magnet motor rotor structure according to claim 3, characterized in that, The number of the rotor magnetic pole units (14) is four.

5. The rotor structure of an interior permanent magnet motor according to claim 1 or 2 or 3 or 4, characterized in that, In each outer magnetic bridge (8), the number of outer magnetic blocks (7) is equal to the number of layers of permanent magnet grooves (15).

6. The rotor structure of an interior permanent magnet motor according to claim 1 or 2 or 3 or 4, characterized in that, When the number of inner magnetic blocks (1) in the inner magnetic bridge (2) is one, the width of the inner magnetic block (1) is equal to the width of the inner magnetic bridge (2).

7. The rotor structure of an interior permanent magnet motor according to claim 1 or 2 or 3 or 4, characterized in that, The inner magnetic block (1), the outer magnetic block (7), the inner magnetic bridge (2), the outer magnetic bridge (8) and the magnetic conductive core form a whole.

8. An interior permanent magnet motor rotor structure according to claim 7, characterized by The inner magnetic block (1) and the outer magnetic block (7) are subjected to nitriding treatment.

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