Rotor structure of motor and motor

Abstract

The utility model discloses a motor rotor structure and a motor, comprising a rotor core having a plurality of magnetic poles, each magnetic pole having a magnetic pole center line, the magnetic pole center line passing through the center point of the rotor core along the radial direction, at least two layers of magnetic steel grooves, at least two layers of magnetic steel and at least one air groove arranged at intervals along the radial direction in any magnetic pole, each layer of magnetic steel is arranged in the magnetic steel groove of the corresponding layer; wherein the first-layer magnetic steel grooves are close to the outer edge of the rotor core relative to the second-layer magnetic steel grooves, the air grooves are arranged between the first-layer magnetic steel grooves and the second-layer magnetic steel grooves, and the magnetic steel in the first-layer magnetic steel grooves is rare earth magnetic steel. According to the embodiment of the utility model, the air slots are arranged between the two layers of magnetic steel slots, so that the magnetic density between the air slots and the adjacent magnetic steel slots is not excessively saturated, the output capability of the motor is ensured, and meanwhile, the layer of magnetic steel close to the outer edge of the rotor core is arranged as rare earth magnetic steel, so that irreversible demagnetization of the magnetic steel at the outer edge of the rotor structure is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a rotor structure of a motor and a motor. Background Art

[0002] As people pay more and more attention to environmental protection and energy efficiency, the automotive industry is moving towards the consensus of the new four modernizations, and the development momentum of electric vehicles is becoming more and more rapid. In this process, battery technology, motor technology and motor controller technology are regarded as the three cores of the development of new energy vehicles. Given that the current battery technology has not made significant breakthroughs, improving the efficiency, power density, safety and reliability of the motor drive system has become the focus of the research and development of the motor drive system of new energy vehicles.

[0003] Permanent magnet assisted synchronous reluctance motor is widely used in the motor drive system of pure electric or hybrid new energy vehicles because of its advantages such as high torque density, high efficiency, good steady-state and high reliability.

[0004] The rotor of the permanent magnet assisted synchronous reluctance motor adopts a multi-layer magnetic barrier structure to obtain a higher reluctance torque. However, since the magnetic steel material commonly used in the permanent magnet assisted synchronous reluctance motor is ferrite, the residual magnetic density and coercive force of the magnetic steel of this material are small, and irreversible demagnetization is prone to occur, affecting the normal operation of the motor.

[0005] In addition, the mechanical strength of the permanent magnet assisted synchronous reluctance motor rotor is also one of the difficulties in design and manufacturing. When the motor is running at high speed, the centrifugal force increases significantly, which is far greater than the influence of other forces, and the magnitude of the centrifugal force is proportional to the square of the rotational speed. As the rotational speed increases, the centrifugal force increases significantly, and the problem of insufficient mechanical strength of the rotor and thus damage to the rotor may occur under high-speed conditions. Utility Model Content

[0006] The utility model aims to provide a rotor structure of a motor and a motor, aiming to solve the problems in the prior art that the motor is prone to irreversible demagnetization and the rotor is damaged due to insufficient mechanical strength under high-speed working conditions.

[0007] The present invention provides a rotor structure of a motor, comprising: a rotor core, the rotor core having a plurality of magnetic poles, each magnetic pole having a magnetic pole center line, the magnetic pole center line passing through the center point of the rotor core in the radial direction, at least two layers of magnetic steel slots, at least two layers of magnetic steel and at least one air slot being arranged radially at intervals in any magnetic pole, each layer of magnetic steel being arranged in the magnetic steel slot of the corresponding layer;

[0008] Among them, the at least two layers of magnetic steel slots include a first layer of magnetic steel slots and a second layer of magnetic steel slots, the first layer of magnetic steel slots are closer to the outer edge of the rotor core relative to the second layer of magnetic steel slots, the air slots are arranged between the first layer of magnetic steel slots and the second layer of magnetic steel slots, and the magnetic steel in the first layer of magnetic steel slots is rare earth magnetic steel.

[0009] Optionally, the first layer of magnetic steel slots includes a first magnetic steel slot and a second magnetic steel slot, the magnetic steels in the first magnetic steel slot and the second magnetic steel slot are respectively the first magnetic steel and the second magnetic steel, wherein the first layer of magnetic steel slots has a V-shaped structure, and the opening of the V-shaped structure faces the outer edge of the rotor core.

[0010] Optionally, a side of the first magnetic steel slot that contacts the first magnetic steel and is close to the outer edge of the rotor core is a first side of the first magnetic steel slot, and an end of the first side of the first magnetic steel slot that is close to the outer edge of the rotor core is connected to the second side of the first magnetic steel slot;

[0011] The side of the second magnetic steel slot that contacts the second magnetic steel and is close to the outer edge of the rotor core is the first side of the second magnetic steel slot, and the end of the first side of the second magnetic steel slot that is close to the outer edge of the rotor core is connected to the second side of the second magnetic steel slot;

[0012] The angle between the first side of the first magnetic steel slot and the first side of the second magnetic steel slot is MA, the angle between the second side of the first magnetic steel slot and the second side of the second magnetic steel slot is MB, and the value range of MA is 132° to 138°;

[0013] There is a constraint relationship between MA and MB: MA-MB=19°~22°.

[0014] Optionally, the thickness of the first magnetic steel and the second magnetic steel is MH, and the value range of MH is 3.5 mm to 5 mm.

[0015] Optionally, the second layer of magnetic steel slots includes a third magnetic steel slot, a fourth magnetic steel slot and a fifth magnetic steel slot, and the magnetic steels in the third magnetic steel slot, the fourth magnetic steel slot and the fifth magnetic steel slot are respectively the third magnetic steel, the fourth magnetic steel and the fifth magnetic steel, wherein the second layer of magnetic steel slots is a U-shaped structure, and the opening of the U-shaped structure faces the outer edge of the rotor core, wherein the third magnetic steel slot and the fourth magnetic steel slot are respectively the two U-shaped sides of the U-shaped structure, and the fifth magnetic steel slot is the U-shaped bottom of the U-shaped structure.

[0016] Optionally, the edge of the third magnetic steel slot close to the center line of the magnetic pole is the first edge of the third magnetic steel slot, and the first edge of the third magnetic steel slot is connected to the second edge of the third magnetic steel slot at one end close to the center point of the rotor core, and the edge of the fourth magnetic steel slot close to the center line of the magnetic pole is the first edge of the fourth magnetic steel slot, and the first edge of the fourth magnetic steel slot is connected to the second edge of the fourth magnetic steel slot at one end close to the center point of the rotor core.

[0017] Optionally, the first side of the third magnetic steel slot is connected to the second side of the third magnetic steel slot by an arc transition at one end close to the center point of the rotor core, and the first side of the fourth magnetic steel slot is connected to the second side of the fourth magnetic steel slot by an arc transition at one end close to the center point of the rotor core.

[0018] Optionally, the edge of the fifth magnetic steel slot that is perpendicular to the center line of the magnetic pole and close to the outer edge of the rotor core is the first edge of the fifth magnetic steel slot, and the two ends of the first edge of the fifth magnetic steel slot are respectively connected to the second edge of the fifth magnetic steel slot and the third edge of the fifth magnetic steel slot, and a first magnetic isolation bridge Q1 is formed between the second edge of the third magnetic steel slot and the second edge of the fifth magnetic steel slot; a second magnetic isolation bridge Q2 is formed between the second edge of the fourth magnetic steel slot and the third edge of the fifth magnetic steel slot.

[0019] Optionally, the sides of the air slot close to the first magnetic steel slot and the second magnetic steel slot are the first side of the air slot and the second side of the air slot respectively; the sides of the air slot close to the third magnetic steel slot and the fourth magnetic steel slot are the third side of the air slot and the fourth side of the air slot respectively; the side of the air slot close to the fifth magnetic steel slot is the fifth side of the air slot, and the fifth side of the air slot is perpendicular to the center line of the magnetic pole.

[0020] Optionally, the angle between the first side of the air slot and the second side of the air slot is KA, the angle between the third side of the air slot and the fourth side of the air slot is KB, and the angle between the first side of the third magnetic steel slot and the first side of the fourth magnetic steel slot is MC, wherein MA-KA=±3°, MC-KB=±3°.

[0021] Optionally, the intersection of the first side of the air slot and the extension line of the second side of the air slot is M, the intersection of the fifth side of the air slot and the center line of the magnetic pole is N, the intersection of the first side of the fifth magnetic steel slot and the center line of the magnetic pole is P, the distance from point P to the center point O of the rotor core is OP, and the value range of OP is: 37mm~42mm; the distance from point N to point P is NP, and the value range of NP is 5mm~6mm, the distance from point M to point N is MN, and the value range of MN is (0.002mm~0.0022mm)*nmax / rpm, where nmax is the maximum speed of the motor.

[0022] Optionally, the first magnetic isolation bridge Q1 has a first center line, the second magnetic isolation bridge Q2 has a second center line, the distance between the intersection of the extended line between the third side of the air slot and the fifth side of the air slot and the first center line is L, and the distance between the intersection of the extended line between the fourth side of the air slot and the fifth side of the air slot and the second center line is also L, and the value range of L is 0mm to 0.5mm.

[0023] An embodiment of the utility model further provides a motor, comprising the rotor structure of the motor as described in any one of the above items.

[0024] The embodiment of the utility model sets an air slot between two layers of magnetic steel slots so that the magnetic density between the air slots and the adjacent magnetic steel slots is not over-saturated, thereby ensuring the output capacity of the motor. At the same time, a layer of magnetic steel close to the outer edge of the rotor core is set to rare earth magnetic steel to prevent irreversible demagnetization of the magnetic steel on the outer edge of the rotor structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of the rotor structure of a motor provided by an embodiment of the utility model;

[0027] Figure 2 A schematic diagram of one eighth of the rotor structure of the motor provided in an embodiment of the utility model;

[0028] Figure 3 Another structural schematic diagram of one eighth of the rotor structure of the motor provided by the embodiment of the utility model;

[0029] Figure 4 A schematic diagram of the partial structure of the first layer of magnetic steel slots of the rotor structure of the motor provided by the embodiment of the utility model;

[0030] Figure 5 Another structural schematic diagram of one eighth of the rotor structure of the motor provided by the embodiment of the utility model;

[0031] Figure 6 Another structural schematic diagram of one eighth of the rotor structure of the motor provided by the embodiment of the utility model;

[0032] Figure 7 A schematic diagram of a partially enlarged structure of a magnetic isolation bridge of a rotor structure provided by an embodiment of the utility model;

[0033] Figure 8 Another structural schematic diagram of a partially enlarged magnetic isolation bridge of a rotor structure provided in an embodiment of the utility model.

[0034] Description of the symbols in the figure:

[0035] 1. Rotor core;

[0036] 2. Magnetic steel slot; 21. Magnetic steel slot of the first layer; 211. Magnetic steel slot of the first layer; 2111. Magnetic steel slot of the first layer; 2112. Magnetic steel slot of the first layer; 2121. Magnetic steel slot of the second layer; 2122. Magnetic steel slot of the second layer; 221. Magnetic steel slot of the third layer; 2211. Magnetic steel slot of the third layer; 2212. Magnetic steel slot of the third layer; 222. Magnetic steel slot of the fourth layer; 2221. Magnetic steel slot of the fourth layer; 2222. Magnetic steel slot of the fourth layer; 2221. Magnetic steel slot of the first layer; 2222. Magnetic steel slot of the fourth layer; 2223. Magnetic steel slot of the fifth layer; 2231. Magnetic steel slot of the first layer; 2232. Magnetic steel slot of the fifth layer; 2233. Magnetic steel slot of the fifth layer;

[0037] 3. Magnetic steel; 31. First magnetic steel; 32. Second magnetic steel; 33. Third magnetic steel; 34. Fourth magnetic steel; 35. Fifth magnetic steel;

[0038] 4. Air slot; 41. First side of air slot; 42. Second side of air slot; 43. Third side of air slot; 44. Fourth side of air slot; 45. Fifth side of air slot. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0041] It should also be understood that the terms used in this utility model specification are only for the purpose of describing specific embodiments and are not intended to limit the utility model. As used in this utility model specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0042] It should be further understood that the term “and / or” used in the present specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0043] See also Figures 1 to 3 The present invention provides a rotor structure of a motor, which includes: a rotor core 1, the rotor core 1 having a plurality of magnetic poles, each magnetic pole having a magnetic pole center line I, the magnetic pole center line I radially passing through a center point O of the rotor core 1, at least two layers of magnetic steel slots 2, at least two layers of magnetic steel 3 and at least one air slot 4 are radially spaced in any magnetic pole, and each layer of magnetic steel 3 is arranged in a magnetic steel slot 2 of a corresponding layer;

[0044] Among them, at least two layers of magnetic steel slots 2 include a first layer of magnetic steel slots 21 and a second layer of magnetic steel slots 22. The first layer of magnetic steel slots 21 are closer to the outer edge of the rotor core 1 relative to the second layer of magnetic steel slots 22. The air slots 4 are arranged between the first layer of magnetic steel slots 21 and the second layer of magnetic steel slots 22. The magnetic steel 3 in the first layer of magnetic steel slots 21 is a rare earth magnetic steel.

[0045] In this embodiment, Figure 1 FIG. 1 is a complete schematic diagram of the rotor structure of the motor. The rotor core 1 is provided with a magnetic steel slot 2, a magnetic steel 3, and an air slot 4. The magnetic steel 3 is installed in the magnetic steel slot 2. The rotor structure includes eight magnetic poles, which are arranged along the circumferential direction. One magnetic pole occupies one eighth of the rotor structure. Figure 2 , Figure 3 as well as Figure 5 and Figure 6 That is the structural schematic diagram of one-eighth model of the rotor structure, that is, one magnetic pole of the rotor, and each magnetic pole is symmetrical about its own magnetic pole center line I.

[0046] Since the first layer of magnetic steel slots 21 are close to the outer edge of the rotor core 1, irreversible demagnetization is prone to occur, which in turn leads to a decrease in the output capacity of the motor and affects the motor performance. Therefore, the magnetic steel 3 in the first layer of magnetic steel slots 21 is set as rare earth magnetic steel. The remanent magnetic density and coercive force of rare earth magnetic steel are relatively high, which can improve the anti-demagnetization ability of the magnetic steel 3, prevent the motor from irreversible demagnetization, and ensure the output capacity of the motor. In addition, the magnetic steel 3 in the first layer of magnetic steel slots 21 can increase the air gap magnetic density and improve the output torque of the motor; the magnetic steel 3 in the second layer of magnetic steel slots 22 is set as ferrite, but the remanent magnetic density and coercive force of ferrite material magnetic steel are relatively small, so this material is not set on the magnetic steel 3 of the first layer of magnetic steel slots 21; in addition, the air slot 4 is located between the first layer of magnetic steel slots 21 and the second layer of magnetic steel slots 22. Its main function is to adjust the distribution and intensity of the magnetic field. By reasonably designing the position of the air slot 4, the magnetic density between the air slot and the adjacent magnetic steel slot is not over-saturated, ensuring the output capacity of the motor, thereby further improving the performance of the motor.

[0047] Specifically, Figure 3 As shown, the first layer of magnetic steel slots 21 includes a first magnetic steel slot 211 and a second magnetic steel slot 212, and the magnetic steels 3 in the first magnetic steel slots 211 and the second magnetic steel slots 212 are respectively the first magnetic steel 31 and the second magnetic steel 32, wherein the first layer of magnetic steel slots 21 are in a V-shaped structure, and the opening of the V-shaped structure faces the outer edge of the rotor core 1. In this embodiment, by reasonably arranging the first magnetic steel slots 211 and the second magnetic steel slots 212, it can be ensured that the rotor still has sufficient mechanical strength when running at high speed, so that the motor can output a larger torque.

[0048] Further, combined with Figure 3 and Figure 4 As shown, the side of the first magnetic steel slot 211 that contacts the first magnetic steel 31 and is close to the outer edge of the rotor core 1 is the first magnetic steel slot first side 2111, and the end of the first magnetic steel slot first side 2111 close to the outer edge of the rotor core 1 is connected to the first magnetic steel slot second side 2112; the side of the second magnetic steel slot 212 that contacts the second magnetic steel 32 and is close to the outer edge of the rotor core 1 is the second magnetic steel slot first side 2121, and the end of the second magnetic steel slot first side 2121 close to the outer edge of the rotor core 1 is connected to the second magnetic steel slot second side 2122;

[0049] The angle between the first side 2111 of the first magnetic steel slot and the first side 2121 of the second magnetic steel slot is MA, the angle between the second side 2112 of the first magnetic steel slot and the second side 2122 of the second magnetic steel slot is MB, and the value range of MA is 132° to 138°;

[0050] There is a constraint relationship between MA and MB: MA-MB=19°~22°.

[0051] Preferably, MA=134.8°, and the value of MA can increase the motor output torque and reduce the motor torque pulsation. Preferably, MA-MB=20°. This constraint relationship allows sufficient air gap between the corners of the first magnetic steel slot 211 and the second magnetic steel slot 212 close to the outer edge of the rotor core 1 and the rotor core 1, which can effectively reduce the irreversible demagnetization of the first magnetic steel 31 and the second magnetic steel 32. Optionally, by adjusting the value range of MA and MB, different application scenarios and performance requirements can be adapted. For example, in applications that require high torque output, the value of MA can be appropriately increased; and in applications that require low noise, the values ​​of MA and MB can be reduced.

[0052] In this embodiment, the thickness of the first magnetic steel 31 and the second magnetic steel 32 is MH, and the value range of MH is 3.5mm-5mm. Preferably, MH=4mm, and the value of the thickness MH of the magnetic steel 3 can ensure the output torque of the motor and reduce the irreversible demagnetization of the first magnetic steel 31 and the second magnetic steel 32.

[0053] Furthermore, the second layer of magnetic steel slots 22 include a third magnetic steel slot 221, a fourth magnetic steel slot 222 and a fifth magnetic steel slot 223, and the magnetic steels 3 in the third magnetic steel slot 221, the fourth magnetic steel slot 222 and the fifth magnetic steel slot 223 are respectively the third magnetic steel 33, the fourth magnetic steel 34 and the fifth magnetic steel 35, wherein the second layer of magnetic steel slots 22 are a U-shaped structure, and the opening of the U-shaped structure faces the outer edge of the rotor core 1, wherein the third magnetic steel slot 221 and the fourth magnetic steel slot 222 are respectively the two U-shaped sides of the U-shaped structure, and the fifth magnetic steel slot 223 is the U-shaped bottom of the U-shaped structure.

[0054] In this embodiment, the third magnetic steel slot 221 and the fourth magnetic steel slot 222 serve as two U-shaped sides of the U-shaped structure, accommodating the third magnetic steel 33 and the fourth magnetic steel 34 respectively. The position and angle design of the third magnetic steel 33 and the fourth magnetic steel 34 ensure that they can interact with the magnetic field of the outer edge of the rotor core 1 to the maximum extent, thereby improving the electromagnetic efficiency and torque output capacity of the motor.

[0055] Specifically, Figure 5 As shown, the edge of the third magnetic steel slot 221 close to the magnetic pole center line I is the third magnetic steel slot first edge 2211, and the first edge 2211 of the third magnetic steel slot is connected to the third magnetic steel slot second edge 2212 at one end close to the center point O of the rotor core 1, and the edge of the fourth magnetic steel slot 222 close to the magnetic pole center line I is the fourth magnetic steel slot first edge 2221, and the first edge 2221 of the fourth magnetic steel slot is connected to the fourth magnetic steel slot second edge 2222 at one end close to the center point O of the rotor core 1.

[0056] By rationally arranging the positional relationship between the third magnetic steel slot 221 and the fourth magnetic steel slot 222 and the magnetic pole center line I and the center point O of the rotor core 1, the technical effect of enhancing electromagnetic performance and improving motor reliability and stability can be achieved.

[0057] The first side 2211 of the third magnetic steel slot is connected to the second side 2212 of the third magnetic steel slot by an arc transition near the center point O of the rotor core 1, and the first side 2221 of the fourth magnetic steel slot is connected to the second side 2222 of the fourth magnetic steel slot by an arc transition near the center point O of the rotor core 1.

[0058] During the operation of the motor, the rotor core 1 and the magnetic steel slot 2 will be affected by various forces, such as centrifugal force, electromagnetic force, etc. If the corners of the magnetic steel slot 2 are too sharp, then under the action of these forces, stress concentration will easily occur at the corners, causing material damage. The arc transition connection can evenly disperse these forces over a larger area, thereby greatly reducing the risk of stress concentration and improving the reliability and durability of the motor.

[0059] Furthermore, the edge of the fifth magnetic steel slot 223 that is perpendicular to the magnetic pole center line I and close to the outer edge of the rotor core 1 is the first edge 2231 of the fifth magnetic steel slot, and the two ends of the first edge 2231 of the fifth magnetic steel slot are respectively connected to the second edge 2232 of the fifth magnetic steel slot and the third edge 2233 of the fifth magnetic steel slot, and the second edge 2212 of the third magnetic steel slot and the second edge 2232 of the fifth magnetic steel slot form a first magnetic isolation bridge Q1; the second edge 2222 of the fourth magnetic steel slot and the third edge 2233 of the fifth magnetic steel slot form a second magnetic isolation bridge Q2.

[0060] In this embodiment, the two ends of the first side 2231 of the fifth magnetic steel slot are respectively connected to the second side 2232 of the fifth magnetic steel slot and the third side 2233 of the fifth magnetic steel slot through arc transition, which greatly reduces the risk of stress concentration and improves the reliability and durability of the motor.

[0061] In the prior art, the permanent magnet assisted synchronous reluctance motor will increase the magnetic isolation bridge to maintain the mechanical strength of the motor during operation. However, since the width of the magnetic isolation bridge is usually small, the effect of centrifugal force is particularly prominent when the motor is running at high speed. The magnitude of the centrifugal force is proportional to the square of the rotation speed. As the rotation speed increases, the centrifugal force increases significantly, and the problem of excessive stress on the magnetic isolation bridge causing damage to the rotor is prone to occur. Therefore, in this embodiment, by forming a first magnetic isolation bridge Q1 between the second edge 2212 of the third magnetic steel slot and the second edge 2232 of the fifth magnetic steel slot, and forming a second magnetic isolation bridge Q2 between the second edge 2222 of the fourth magnetic steel slot and the third edge 2233 of the fifth magnetic steel slot, the centrifugal force on the rotor core 1 during high-speed rotation is greatly reduced, and the stress on the first magnetic isolation bridge Q1 and the second magnetic isolation bridge Q2 is reduced, and the problem of increased local stress on the magnetic isolation bridge caused by the combined effect of stretching and bending on the magnetic isolation bridge is solved, thereby improving the mechanical strength of the motor, improving the reliability of the motor, and ensuring the electromagnetic performance and torque output capacity of the motor.

[0062] In this embodiment, if Figure 6 As shown, the sides of the air slot 4 close to the first magnetic steel slot 211 and the second magnetic steel slot 212 are the first air slot side 41 and the second air slot side 42 respectively; the sides of the air slot 4 close to the third magnetic steel slot 221 and the fourth magnetic steel slot 222 are the third air slot side 43 and the fourth air slot side 44 respectively; the side of the air slot 4 close to the fifth magnetic steel slot 223 is the fifth air slot side 45, and the fifth air slot side 45 is perpendicular to the magnetic pole center line I. By designing each side of the air slot 4, the magnetic flux density between each side of the air slot 4 and the adjacent magnetic steel slot 2 is not over-saturated, thereby ensuring the output capacity of the motor.

[0063] It should be noted that the two connected edges of the air groove 4 are connected by an arc transition, that is, the first edge 41 of the air groove is connected to the third edge 43 of the air groove by an arc transition, the third edge 43 of the air groove is connected to the fifth edge 44 of the air groove by an arc transition, the second edge 42 of the air groove is connected to the fourth edge 44 of the air groove by an arc transition, the fourth edge 414 of the air groove is connected to the fifth edge 44 of the air groove by an arc transition, and the arc radii of the two connected edges are consistent, and the arc radius ranges from r2 to r4, wherein r2 refers to the fillet radius of 2 mm, and r4 refers to the fillet radius of 4 mm, that is, the arc radius ranges from 2 to 4 mm.

[0064] Furthermore, the angle between the first side 41 of the air slot and the second side 42 of the air slot is KA, the angle between the third side 43 of the air slot and the fourth side 44 of the air slot is KB, and the angle between the first side 2211 of the third magnetic steel slot and the first side 2221 of the fourth magnetic steel slot is MC, wherein MA-KA=±3°, MC-KB=±3°.

[0065] Preferably, MA-KA=0°, MC-KB=0°. This constraint relationship can prevent the rotor core 1 from being over-saturated with local magnetic flux density, thereby affecting the output capacity of the motor.

[0066] In this embodiment, the intersection of the extended lines of the first side 41 of the air slot and the second side 42 of the air slot is M, the intersection of the fifth side 45 of the air slot and the magnetic pole center line I is N, the intersection of the first side 2231 of the fifth magnetic steel slot and the magnetic pole center line I is P, the distance from point P to the center point O of the rotor core 1 is OP, and the value range of OP is: 37mm~42mm; the distance from point N to point P is NP, and the value range of NP is 5mm~6mm, the distance from point M to point N is MN (the radial distance of the air slot 4 on the magnetic pole center line I), and the value range of MN is (0.002mm~0.0022mm)*nmax / rpm, nmax is the maximum speed of the motor, rpm is the unit of speed, indicating revolutions per minute, and the value of MN is related to the maximum speed of the motor (in rpm). Specifically, when the maximum speed of the motor is 1 rpm, the value range of MN will be a value between 0.002 mm and 0.0022 mm. When the speed of the motor increases, the value range of MN will increase in proportion to the maximum speed.

[0067] Preferably, OP=39.5mm, NP=5.87mm, MN=0.002163mm*nmax / rpm. The above constraint relationship can reduce the maximum stress on the rotor core 1 when the motor runs at high speed, improve the mechanical strength of the rotor core 1, and improve the reliability of the motor; ensure that the rotor core 1 meets the strength requirements at different maximum speeds.

[0068] like Figure 7 As shown, the first magnetic isolation bridge Q1 has a first center line II, the second magnetic isolation bridge Q2 has a second center line III, the distance from the intersection of the extended line between the third side 43 of the air slot and the fifth side 45 of the air slot to the first center line II is L, and the distance from the intersection of the extended line between the fourth side 44 of the air slot and the fifth side 45 of the air slot to the second center line III is also L, and the value range of L is 0mm~0.5mm.

[0069] In this embodiment, if Figure 8As shown, the intersection of the extended lines between the third side 43 of the air slot and the fifth side 45 of the air slot is located on the side of the center line of the magnetic isolation bridge close to the third magnetic steel slot 221, and the intersection of the extended lines between the fourth side 44 of the air slot and the fifth side 45 of the air slot is located on the side of the center line of the magnetic isolation bridge close to the fourth magnetic steel slot 222. In other embodiments, the intersection of the extended lines between the third side 43 of the air slot and the fifth side 45 of the air slot is located on the side of the center line of the magnetic isolation bridge close to the fifth magnetic steel slot 223, and the intersection of the extended lines between the fourth side 44 of the air slot and the fifth side 45 of the air slot is located on the side of the center line of the magnetic isolation bridge close to the fifth magnetic steel slot 223.

[0070] Preferably, L = 0 mm, such as Figure 7 As shown, this is one of the cases where the intersection of the extension lines is located on the corresponding first center line II. When the rotor is running at high speed, the effect of the centrifugal force of the rotor is particularly prominent. The maximum stress point of the rotor core 1 often appears on the magnetic isolation bridge close to the rotor center point O. Reducing the maximum stress on the magnetic isolation bridge can effectively improve the mechanical strength of the rotor core 1. The setting of L can make the stress direction of the first magnetic isolation bridge Q1 and the second magnetic isolation bridge Q2 parallel to the direction of the corresponding magnetic isolation bridge, avoiding the first magnetic isolation bridge Q1 and the second magnetic isolation bridge Q2 from being stretched and bent, preventing the first magnetic isolation bridge Q1 and the second magnetic isolation bridge Q2 from being excessively stressed locally, making the stress on the first magnetic isolation bridge Q1 and the second magnetic isolation bridge Q2 more uniform, reducing the maximum stress on the first magnetic isolation bridge Q1 and the second magnetic isolation bridge Q2, improving the mechanical strength of the rotor, and improving the reliability of the motor.

[0071] An embodiment of the utility model further provides a motor, comprising the rotor structure of the motor as described above.

[0072] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

[0073] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive.

[0074] Inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "including a..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A rotor structure of a motor, characterized in that: The rotor core comprises a plurality of magnetic poles, each magnetic pole has a magnetic pole center line, the magnetic pole center line passes through the center point of the rotor core in the radial direction, at least two layers of magnetic steel slots, at least two layers of magnetic steel and at least one air slot are arranged radially in any magnetic pole, and each layer of magnetic steel is arranged in the magnetic steel slot of the corresponding layer; Among them, the at least two layers of magnetic steel slots include a first layer of magnetic steel slots and a second layer of magnetic steel slots, the first layer of magnetic steel slots are closer to the outer edge of the rotor core relative to the second layer of magnetic steel slots, the air slots are arranged between the first layer of magnetic steel slots and the second layer of magnetic steel slots, and the magnetic steel in the first layer of magnetic steel slots is rare earth magnetic steel.

2. The rotor structure of the motor according to claim 1, characterized in that: The first layer of magnetic steel slots includes a first magnetic steel slot and a second magnetic steel slot, the magnetic steels in the first magnetic steel slot and the second magnetic steel slot are respectively the first magnetic steel and the second magnetic steel, wherein the first layer of magnetic steel slots is a V-shaped structure, and the opening of the V-shaped structure faces the outer edge of the rotor core.

3. The rotor structure of the motor according to claim 2, characterized in that: The side of the first magnetic steel slot that contacts the first magnetic steel and is close to the outer edge of the rotor core is the first side of the first magnetic steel slot, and the end of the first side of the first magnetic steel slot that is close to the outer edge of the rotor core is connected to the second side of the first magnetic steel slot; The side of the second magnetic steel slot that contacts the second magnetic steel and is close to the outer edge of the rotor core is the first side of the second magnetic steel slot, and the end of the first side of the second magnetic steel slot that is close to the outer edge of the rotor core is connected to the second side of the second magnetic steel slot; The angle between the first side of the first magnetic steel slot and the first side of the second magnetic steel slot is MA, the angle between the second side of the first magnetic steel slot and the second side of the second magnetic steel slot is MB, and the value range of MA is 132° to 138°; There is a constraint relationship between MA and MB: MA-MB=19°~22°.

4. The rotor structure of the motor according to claim 2, characterized in that: The thickness of the first magnetic steel and the second magnetic steel is MH, and the value range of MH is 3.5 mm to 5 mm.

5. The rotor structure of the motor according to claim 2, characterized in that: The second layer of magnetic steel slots includes a third magnetic steel slot, a fourth magnetic steel slot and a fifth magnetic steel slot, wherein the magnetic steels in the third magnetic steel slot, the fourth magnetic steel slot and the fifth magnetic steel slot are respectively the third magnetic steel, the fourth magnetic steel and the fifth magnetic steel, wherein the second layer of magnetic steel slots is a U-shaped structure, and the opening of the U-shaped structure faces the outer edge of the rotor core, wherein the third magnetic steel slot and the fourth magnetic steel slot are respectively the two U-shaped sides of the U-shaped structure, and the fifth magnetic steel slot is the U-shaped bottom of the U-shaped structure.

6. The rotor structure of the motor according to claim 5, characterized in that: The side of the third magnetic steel slot close to the center line of the magnetic pole is the first side of the third magnetic steel slot, and the first side of the third magnetic steel slot is connected to the second side of the third magnetic steel slot at one end close to the center point of the rotor core. The side of the fourth magnetic steel slot close to the center line of the magnetic pole is the first side of the fourth magnetic steel slot, and the first side of the fourth magnetic steel slot is connected to the second side of the fourth magnetic steel slot at one end close to the center point of the rotor core.

7. The rotor structure of the motor according to claim 6, characterized in that: The first side of the third magnetic steel slot is connected to the second side of the third magnetic steel slot by an arc transition at one end close to the center point of the rotor core, and the first side of the fourth magnetic steel slot is connected to the second side of the fourth magnetic steel slot by an arc transition at one end close to the center point of the rotor core.

8. The rotor structure of the motor according to claim 6, characterized in that: The edge of the fifth magnetic steel slot that is perpendicular to the center line of the magnetic pole and close to the outer edge of the rotor core is the first edge of the fifth magnetic steel slot. The two ends of the first edge of the fifth magnetic steel slot are respectively connected to the second edge of the fifth magnetic steel slot and the third edge of the fifth magnetic steel slot. A first magnetic isolation bridge Q1 is formed between the second edge of the third magnetic steel slot and the second edge of the fifth magnetic steel slot. A second magnetic isolation bridge Q2 is formed between the second edge of the fourth magnetic steel slot and the third edge of the fifth magnetic steel slot.

9. The rotor structure of the motor according to claim 8, characterized in that: The sides of the air slot close to the first magnetic steel slot and the second magnetic steel slot are the first side of the air slot and the second side of the air slot respectively; the sides of the air slot close to the third magnetic steel slot and the fourth magnetic steel slot are the third side of the air slot and the fourth side of the air slot respectively; the side of the air slot close to the fifth magnetic steel slot is the fifth side of the air slot, and the fifth side of the air slot is perpendicular to the center line of the magnetic pole.

10. The rotor structure of the motor according to claim 9, characterized in that: The angle between the first side of the air slot and the second side of the air slot is KA, the angle between the third side of the air slot and the fourth side of the air slot is KB, and the angle between the first side of the third magnetic steel slot and the first side of the fourth magnetic steel slot is MC, wherein MA-KA=±3°, MC-KB=±3°.

11. The rotor structure of the motor according to claim 9, characterized in that: The intersection of the first side of the air slot and the extension line of the second side of the air slot is M, the intersection of the fifth side of the air slot and the center line of the magnetic pole is N, the intersection of the first side of the fifth magnetic steel slot and the center line of the magnetic pole is P, the distance from point P to the center point O of the rotor core is OP, and the value range of OP is: 37mm~42mm; the distance from point N to point P is NP, and the value range of NP is 5mm~6mm, the distance from point M to point N is MN, and the value range of MN is (0.002mm~0.0022mm) *nmax / rpm, nmax is the maximum speed of the motor.

12. The rotor structure of the motor according to claim 9, characterized in that: The first magnetic isolation bridge Q1 has a first center line, the second magnetic isolation bridge Q2 has a second center line, the distance from the intersection of the extended line between the third side of the air slot and the fifth side of the air slot to the first center line is L, and the distance from the intersection of the extended line between the fourth side of the air slot and the fifth side of the air slot to the second center line is also L, and the value range of L is 0mm~0.5mm.

13. A motor, characterized in that: A rotor structure comprising a motor as claimed in any one of claims 1 to 12.

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