A motor rotor, a motor, a compressor and an air conditioner

Abstract

The present invention belongs to the technical field of motors, and discloses a motor rotor, a motor, a compressor and an air conditioner. The motor rotor is formed by laminating a plurality of rotor punching sheets, and includes a rotor core having a plurality of magnetic poles. A magnetic steel groove is provided under the magnetic poles. A magnetic isolation hole group is arranged on one side of the magnetic steel groove close to the periphery of the motor rotor. The magnetic isolation hole group is symmetric about the d-axis of the motor rotor. A buckle point for fixing a plurality of rotor punching sheets is arranged between the magnetic steel groove and the magnetic isolation hole group; the magnetic isolation hole group includes a plurality of magnetic isolation holes, which are a first magnetic isolation hole arranged on both sides and a second magnetic isolation hole located between the two first magnetic isolation holes. The width of at least one second magnetic isolation hole near the periphery of the motor rotor is smaller than the width away from the periphery of the motor rotor. By defining the width of the second magnetic isolation hole and arranging the buckle point, the magnetic circuit structure inside the rotor is optimized, the sudden change of rotor magnetic density and harmonic content are reduced, thereby reducing the slot tooth torque pulsation, effectively suppressing vibration and noise, and increasing the mechanical strength of the motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly to a motor rotor, a motor, a compressor, and an air conditioner. Background Art

[0002] Permanent magnet synchronous motors have characteristics such as high torque density, low manufacturing cost, and wide high-efficiency regions, and have been widely used in compressors and the household air conditioner field; the miniaturization of compressors is the development trend of compressors. During the process of compressor miniaturization, it is necessary to ensure the power density of the compressor motor, and the resulting increase in motor torque ripple will directly affect the vibration and noise of the motor. Summary of the Invention

[0003] In view of this, the present invention provides a motor rotor, a motor, a compressor, and an air conditioner. By limiting the width of the magnetic isolation holes, the torque ripple is reduced, thereby reducing the vibration and noise of the motor.

[0004] To solve the above problems, according to one aspect of the present application, an embodiment of the present invention provides a motor rotor, which is formed by laminating a plurality of rotor punching sheets. The motor rotor includes a rotor core, the rotor core has a plurality of magnetic poles, a magnetic steel groove is provided under the magnetic poles, a magnetic isolation hole group is arranged on one side of the magnetic steel groove close to the periphery of the motor rotor, the magnetic isolation hole group is symmetric about the d-axis of the motor rotor, and a buckle point for fixing a plurality of rotor punching sheets is arranged between the magnetic steel groove and the magnetic isolation hole group; the magnetic isolation hole group includes a plurality of magnetic isolation holes, which are a first magnetic isolation hole arranged on both sides and a second magnetic isolation hole located between the two first magnetic isolation holes. At least one second magnetic isolation hole satisfies that the width near the periphery of the motor rotor is smaller than the width away from the periphery of the motor rotor.

[0005] In some embodiments, the buckle points are distributed on the center line of the magnetic poles.

[0006] In some embodiments, the buckle point is rectangular, and the length H of the buckle point along the radial direction of the motor rotor satisfies: 2 ≤ H ≤ 4, the width W of the buckle point satisfies: 0.5 ≤ W ≤ 2, and W ≤ H.

[0007] In some embodiments, the second magnetic isolation hole is strip-shaped, and from the direction away from the periphery of the motor rotor to the direction close to the periphery of the motor rotor, the width of at least one second magnetic isolation hole gradually decreases; the remaining second magnetic isolation holes are of equal-width structure.

[0008] In some embodiments, at least one second magnetic isolation hole includes at least two magnetic isolation hole segments, each magnetic isolation hole segment is strip-shaped with equal width, and from the direction away from the periphery of the motor rotor to the direction close to the periphery of the motor rotor, the width of adjacent magnetic isolation hole segments decreases; the remaining second magnetic isolation holes are of equal-width structure.

[0009] In some embodiments, at least one second magnetic isolation hole includes at least two magnetic isolation segments; among all the magnetic isolation segments, in the direction from far away from the periphery of the motor rotor to close to the periphery of the motor rotor, the width of at least one magnetic isolation segment decreases, and the rest are strip-shaped with equal width; the rest of the second magnetic isolation holes are of equal-width structure.

[0010] In some embodiments, both ends of each second magnetic isolation hole are arc-shaped. A plurality of arcs close to the periphery of the motor rotor are all located on the circumference of a first circle, and a plurality of arcs far away from the periphery of the motor rotor are all located on the circumference of a second circle, and R1 ≤ R2, where R1 is the radius of the first circle and R2 is the radius of the second circle.

[0011] In some embodiments, the arc shapes at both ends of each second magnetic isolation hole satisfy: R3 > R4, where R3 is the radius of the arc at the end far away from the periphery of the motor rotor, and R4 is the radius of the arc at the end close to the periphery of the motor rotor.

[0012] In some embodiments, along the direction from the center to both sides, the lengths of a plurality of magnetic isolation holes decrease in sequence.

[0013] In some embodiments, when there are 2n magnetic isolation holes, n of them are located on one side of the d-axis, and the other n magnetic isolation holes are located on the other side of the d-axis; when there are 2n + 1 magnetic isolation holes, n of them are located on one side of the d-axis, and the other n magnetic isolation holes are located on the other side of the d-axis, and one magnetic isolation hole is located on the d-axis; where n is a natural number.

[0014] In some embodiments, when there are 2n + 1 magnetic isolation holes, if the length of the magnetic isolation hole located on the d-axis is H1, then 0 ≤ H1 / H ≤ 4.

[0015] In some embodiments, there is an included angle between the magnetic isolation holes located on the same side of the d-axis and the magnetic steel slots on that side, and the included angle decreases as the magnetic isolation hole gets closer to the d-axis.

[0016] In some embodiments, the included angle between the magnetic isolation hole located on the d-axis and the magnetic steel slot is smaller than the included angle between any other magnetic isolation hole and the magnetic steel slot.

[0017] In some embodiments, the maximum gap L1 between a plurality of magnetic isolation holes and the periphery of the motor rotor satisfies: L1 < L2, where L2 is the width of the magnetic isolation bridge between the magnetic steel slot and the rotor periphery.

[0018] In some embodiments, the minimum width of the magnetic isolation hole is D1, and the width of the magnetic steel slot is D2, then 0.3D2 ≤ D1 ≤ 0.6D2.

[0019] In some embodiments, both ends of a plurality of magnetic isolation holes are arc-shaped or polygonal.

[0020] According to another aspect of the present application, an embodiment of the present invention provides a motor, and the motor includes the above-mentioned motor rotor.

[0021] According to another aspect of the present application, an embodiment of the present invention provides a compressor, and the compressor includes the above-mentioned motor.

[0022] According to another aspect of the present application, an embodiment of the present invention provides an air conditioner, and the air conditioner includes the above-mentioned compressor.

[0023] Compared with the prior art, the motor rotor of the present invention has at least the following beneficial effects:

[0024] First, the width of each part of at least one second magnetic isolation hole is limited to conform to the trend of the lower magnetic circuit of each magnetic pole inside the motor rotor. Such a limitation can make the magnetic resistance under the rotor magnetic pole be exactly positively correlated with the magnetic line density, so that more magnetic lines flow through the place with relatively small magnetic resistance under the magnetic pole, the magnetic density inside the rotor is more evenly distributed, and the magnetic density at the rotor magnetic steel is more uniform. The present invention optimizes the magnetic circuit structure inside the rotor in this way, reduces the sudden change of rotor magnetic density and harmonic content, thereby reducing the slot tooth torque ripple, and can effectively suppress vibration and noise. Second, the motor rotor provided by the present invention adds the design of the buckling point 4. The rotor core 1 is formed by laminating silicon steel sheets (rotor punching sheets) through buckling points. In this embodiment, a buckling point is set at the magnetic pole of the rotor, which is equivalent to adding a point for fixing the rotor punching sheet, so the mechanical strength of the motor can be increased. Moreover, the magnetic isolation hole group is symmetric about the d-axis of the motor rotor, which is beneficial to the sinusoidal distribution of the back electromotive force of the motor and enables the motor to run smoothly.

[0025] On the other hand, the motor provided by the present invention is designed based on the above-mentioned motor rotor, and its beneficial effects can be referred to the beneficial effects of the above-mentioned motor rotor, which will not be elaborated here one by one.

[0026] On the other hand, the compressor provided by the present invention is designed based on the above-mentioned motor, and its beneficial effects can be referred to the beneficial effects of the above-mentioned motor, which will not be elaborated here one by one.

[0027] On the other hand, the air conditioner provided by the present invention is designed based on the above-mentioned compressor, and its beneficial effects can be referred to the beneficial effects of the above-mentioned compressor, which will not be elaborated here one by one.

[0028] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and implement it according to the content of the specification, the following takes the preferred embodiment of the present invention and combines with the drawings to elaborate in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of a motor rotor provided by Embodiment 1 of the present invention;

[0030] Figure 2 is Figure 1 The partial enlarged view at position A in

[0031] Figure 3 Another structural schematic diagram of a motor rotor provided by Embodiment 1 of the present invention;

[0032] Figure 4 is Figure 3 The partial enlarged view at position B in

[0033] Figure 5 Another structural schematic diagram of a motor rotor provided by Embodiment 1 of the present invention;

[0034] Figure 6 is Figure 5 The partial enlarged view at position C in

[0035] Figure 7 Another structural schematic diagram of a motor rotor provided by Embodiment 1 of the present invention;

[0036] Figure 8 A structural schematic diagram of a motor provided by Embodiment 2 of the present invention;

[0037] Figure 9 A structural schematic diagram of a compressor provided by Embodiment 3 of the present invention;

[0038] Figure 10 A comparison diagram of the electromagnetic force of the motor provided by Embodiment 2 of the present invention and that of a common conventional motor;

[0039] Figure 11 A comparison diagram of the noise of the compressor provided by Embodiment 3 of the present invention and that of a common conventional compressor.

[0040] Wherein:

[0041] 1. Rotor core; 2. Magnet slot; 3. Magnetic isolation hole group; 4. Buckle point; 5. Stator; 31. First magnetic isolation hole; 32. Second magnetic isolation hole; 321. Magnetic isolation hole section. Detailed implementation manners

[0042] To further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features, and their effects of the application according to the present invention. In the following description, different "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0043] In the description of the present invention, it should be clear that the terms "first", "second", etc. in the specification, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence; the terms "vertical", "lateral", "longitudinal", "front", "rear", "left", "right", "upper", "lower", "horizontal", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention, rather than meaning that the device or element referred to must have a specific orientation or position, so it cannot be understood as a limitation to the present invention.

[0044] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Embodiment 1

[0046] This embodiment provides a motor rotor, as Figure 1 shown, which is formed by laminating a plurality of rotor laminations. The motor rotor includes a rotor core 1. The rotor core 1 has a plurality of magnetic poles. A magnet slot 2 is provided under the magnetic poles. A magnetic isolation hole group 3 is arranged on one side of the magnet slot 2 close to the periphery of the motor rotor. The magnetic isolation hole group 3 is symmetric about the d-axis of the motor rotor. A buckle point 4 for fixing a plurality of rotor laminations is provided between the magnet slot 2 and the magnetic isolation hole group 3; the magnetic isolation hole group 3 includes a plurality of magnetic isolation holes, which are a first magnetic isolation hole 31 arranged on both sides and a second magnetic isolation hole 32 located between the two first magnetic isolation holes 31. At least one second magnetic isolation hole 32 satisfies that the width near the periphery of the motor rotor is smaller than the width away from the periphery of the motor rotor.

[0047] Specifically, in the control of a permanent magnet synchronous motor, in order to obtain control characteristics similar to those of a DC motor, a coordinate system is established on the motor rotor. This coordinate system rotates synchronously with the rotor, and the direction of the rotor magnetic field is taken as the d-axis. The motor rotor has multiple magnetic poles, and under each magnetic pole, there are two magnet slots 2 symmetrically distributed at a certain angle and symmetric about the d-axis. First, in this embodiment, it is defined that along the radial direction of the rotor core 1, the width of the second magnetic isolation hole 32 close to the periphery of the motor rotor is smaller than the width away from the periphery of the motor rotor, so as to conform to the magnetic circuit trend of each magnetic pole inside the motor rotor. Such a definition can make the magnetic resistance under the rotor magnetic pole exactly positively correlated with the magnetic line density, so that more magnetic lines flow through the place with relatively small magnetic resistance under the magnetic pole, and the magnetic density inside the rotor is more evenly distributed, and the magnetic density at the rotor magnet is more uniform. The present invention optimizes the magnetic circuit structure inside the rotor in this way, reduces the sudden change of rotor magnetic density and harmonic content, thereby reducing the slot tooth torque ripple, and can effectively suppress vibration and noise. Secondly, the motor rotor provided in this embodiment adds the design of the buckling point 4. The rotor core 1 is stacked by silicon steel sheets (rotor punching sheets) through the buckling point. In this embodiment, a buckling point is provided at the magnetic pole of the rotor, which is equivalent to adding a point for fixing the rotor punching sheet, so the mechanical strength of the motor can be increased.

[0048] Moreover, the asymmetric distribution of the magnetic isolation hole group 3 under the rotor magnetic pole will cause uneven distribution of the magnetic density of the motor rotor, increase the distortion degree of the air-gap magnetic density, and is not conducive to the sinusoidal distribution of the motor back electromotive force, thereby affecting the stable operation of the motor. Therefore, in this embodiment, the magnetic isolation hole group 3 is symmetric about the d-axis, which is beneficial to the sinusoidal distribution of the motor back electromotive force and enables the motor to operate stably.

[0049] In a specific embodiment, the buckling points 4 are distributed on the center line of the magnetic pole. The buckling point 4 is rectangular, and the length H of the buckling point 4 along the radial direction of the motor rotor satisfies: 2 ≤ H ≤ 4, and the width W of the buckling point 4 satisfies: 0.5 ≤ W ≤ 2, and W ≤ H. The buckling point 4 with this structure can reduce the influence of the buckling point 4 on the motor performance while ensuring the structural strength of the rotor.

[0050] In a specific embodiment, in order to achieve that the width of the second magnetic isolation hole 32 close to the periphery of the motor rotor is smaller than the width away from the periphery of the motor rotor, there are various specific structures, as follows:

[0051] First, as Figure 1 and Figure 2As shown, the second magnetic isolation hole 32 is strip-shaped, and at least one second magnetic isolation hole 32 gradually decreases in width from a direction away from the periphery of the motor rotor towards a direction closer to the periphery of the motor rotor; specifically, the closer to the periphery of the motor rotor, the smaller the width of the second magnetic isolation hole 32. This structure can be called a gradient structure; the remaining second magnetic isolation holes 32 are of equal width structure; that is to say, in this embodiment, the second magnetic isolation holes 32 are either of the gradient structure or a combination of the gradient structure and the equal width structure; as Figure 6 shown, the second magnetic isolation hole 32 in it is a combination of the gradient structure and the equal width structure, where the second magnetic isolation hole 32 located on the d-axis is of the equal width structure, and the remaining second magnetic isolation holes 32 are of the gradient structure.

[0052] Second, as Figure 3 and Figure 4 shown, at least one second magnetic isolation hole 32 includes at least two magnetic isolation hole segments 321. Each magnetic isolation hole segment 321 is a strip-shaped with equal width, and the width of adjacent magnetic isolation hole segments 321 decreases from a direction away from the periphery of the motor rotor towards a direction closer to the periphery of the motor rotor; for better illustration, assume that the second magnetic isolation hole 32 includes two magnetic isolation hole segments 321, namely the first magnetic isolation hole segment and the second magnetic isolation hole segment. The first magnetic isolation hole segment is closer to the periphery of the motor rotor, and its width is the same everywhere, assumed to be a. The width of the second magnetic isolation hole segment is the same everywhere, assumed to be b, then a < b; assume that the second magnetic isolation hole 32 includes three magnetic isolation hole segments 321, from a direction away from the periphery of the motor rotor towards a direction closer to the periphery of the rotor, they are the first magnetic isolation hole segment, the second magnetic isolation hole segment and the third magnetic isolation hole segment respectively, and their corresponding widths are a, b and c respectively, then there is a > b > c. This structure can be called a mutation structure; the remaining second magnetic isolation holes 32 are of equal width structure; that is to say, in this embodiment, the second magnetic isolation holes 32 are either of the mutation structure or a combination of the mutation structure and the equal width structure.

[0053] Thirdly, at least one second magnetic isolation hole 32 includes at least two magnetic isolation segments; among all the magnetic isolation segments, in the direction from far away from the periphery of the motor rotor to close to the periphery of the motor rotor, the width of at least one magnetic isolation segment decreases, and the rest are strip-shaped with equal width; for better illustration, assume that the second magnetic isolation hole 32 includes two magnetic isolation segments, namely the first magnetic isolation segment and the second magnetic isolation segment. In the direction from far away from the periphery of the motor rotor to close to the periphery of the motor rotor, the width of the first magnetic isolation segment decreases. Then, the width of the second magnetic isolation segment can decrease or be a strip-shaped with equal width, but it is necessary to ensure that the overall trend of the width of the second magnetic isolation hole is decreasing in the direction from far away from the periphery of the motor rotor to close to the periphery of the motor rotor. This structure can be called gradual change to sudden change or sudden change to gradual change; the rest of the second magnetic isolation holes 32 are of equal-width structure; that is to say, in this embodiment, the second magnetic isolation hole 32 is either of the gradual change to sudden change structure, or of the sudden change to gradual change structure, or a combination of the gradual change to sudden change structure and the equal-width structure, or a combination of the sudden change to gradual change structure and the equal-width structure.

[0054] In a specific embodiment, as Figure 7 shown, a plurality of second magnetic isolation holes 32 are provided. Both ends of the plurality of second magnetic isolation holes 32 are arc-shaped. A plurality of arcs close to the periphery of the motor rotor are all located on the circumference of the first circle, and a plurality of arcs far away from the periphery of the motor rotor are all located on the circumference of the second circle. The first circle and the second circle intersect, and R1 ≤ R2, where R1 is the radius of the first circle and R2 is the radius of the second circle.

[0055] By this structure of setting the two end points of the second magnetic isolation hole 32 on the circle, magnetic isolation holes are arranged under each magnetic pole of the rotor. By increasing a magnetic barrier with a size matching the size of the motor rotor, a better magnetic circuit channel is set, so that the magnetic density inside the rotor will not concentrate in places with too high magnetic density, optimizing the magnetic density distribution, improving the magnetic density distribution under each magnetic pole of the rotor, reducing the magnetic density harmonic content in the air gap between the stator and rotor of the motor, and further reducing the radial electromagnetic force and tangential electromagnetic force of each order and multiple frequencies during the operation of the motor, thereby reducing the vibration and noise during the operation of the motor and the compressor.

[0056] In a specific embodiment, as Figure 2 shown, the arc shapes at both ends of each second magnetic isolation hole 32 satisfy: R3 > R4, where R3 is the radius of the arc at the end far away from the periphery of the motor rotor, and R4 is the radius of the arc at the end close to the periphery of the motor rotor. By providing smooth circular ports at both ends of the second magnetic isolation hole 32, it is beneficial for the rotor magnetic circuit to pass through the magnetic poles smoothly, reducing the influence of the armature magnetic field of the motor on the magnetic field under the rotor magnetic poles under heavy load and high load conditions, enabling safe operation under heavy load and high load conditions, and increasing the demagnetization resistance of the motor.

[0057] In a specific embodiment, the magnetic isolation hole group 3 is symmetric about the d-axis of the motor rotor. Along the direction from the center to both sides, the lengths of multiple magnetic isolation holes decrease in sequence; the length of the magnetic isolation hole gradually decreases from the symmetric center to both sides, and both ends are located on the circle. Such a structure can better adapt to the spatial structure under the magnetic poles of the motor rotor. At the same time, because the magnetic lines of force are denser in the middle of the magnetic poles, by increasing the magnetic resistance in this magnetic circuit, the magnetic lines of force passing through under the motor magnetic poles will not be concentrated only in a part of the area, enabling the magnetic flux generated by the stator winding to better couple with the magnetic poles of the rotor, reducing the generation of back electromotive force harmonics, making the back electromotive force closer to a sine wave, reducing the content of back electromotive force harmonics, reducing the motor loss, and improving the motor efficiency.

[0058] In a specific embodiment, when there are 2n magnetic isolation holes, n of them are located on one side of the d-axis, and the other n magnetic isolation holes are located on the other side of the d-axis; when there are 2n + 1 magnetic isolation holes, n of them are located on one side of the d-axis, the other n magnetic isolation holes are located on the other side of the d-axis, and one magnetic isolation hole is located on the d-axis; where n is a natural number; for better explanation, the following specific embodiments are given:

[0059] In one of the embodiments, there are 8 magnetic isolation holes, then 4 of them are located on one side of the d-axis, and the other 4 magnetic isolation holes are located on the other side of the d-axis; in another embodiment, there are 9 magnetic isolation holes, then 4 of them are located on one side of the d-axis, the other four magnetic isolation holes are located on the other side of the d-axis, and the last 1 magnetic isolation hole is located on the d-axis and is symmetric about the d-axis.

[0060] In a specific embodiment, when there are 2n + 1 magnetic isolation holes, the length of the magnetic isolation hole located on the d-axis is H1, then 0 ≤ H1 / H ≤ 4; H is the length of the buckle point 4 along the radial direction of the motor rotor, and 2 ≤ H ≤ 4; the buckle point 4 of this structure and its length relationship with the second magnetic isolation hole 32 on the d-axis can reduce the influence of the buckle point 4 on the motor performance while ensuring the rotor structural strength.

[0061] In a specific embodiment, there is an included angle between the magnetic isolation holes on the same side of the d-axis and the magnetic steel groove 2 on that side, and the included angle decreases as the magnetic isolation hole gets closer to the d-axis; moreover, the included angle between the magnetic isolation hole located on the d-axis and the magnetic steel groove 2 is smaller than the included angle between any other magnetic isolation hole and the magnetic steel groove 2.

[0062] That is to say, among the magnetic isolation holes on the same side of the d-axis, there are several second magnetic isolation holes 32 and one first magnetic isolation hole 31. In the direction from the d-axis to away from the d-axis, the angles between the several second magnetic isolation holes 32 and the first magnetic isolation hole 31 and the magnetic steel groove 2 increase in sequence; this angle setting of the magnetic isolation holes makes the magnetic isolation holes in a divergent shape, which exactly conforms to the fan-shaped area from the stator to the V-shaped magnetic steel groove inside the rotor, enabling the magnetic field generated by the stator tooth part to be better coupled with the magnetic field of the magnetic steel of the rotor. The waveform of the magnetic flux density change of the air-gap magnetic field in the middle is also close to a sine wave, which can optimize the air-gap magnetic flux density waveform and reduce the slot-tooth torque of the motor.

[0063] More specifically, as Figure 2 shown, when the magnetic isolation hole group 3 includes 7 magnetic isolation holes, the middle magnetic isolation hole is located on the d-axis, which is called the axis magnetic isolation hole. The magnetic isolation holes on one side of the d-axis, in the direction from the d-axis to away from the d-axis, are successively the magnetic isolation hole a, the magnetic isolation hole b, and the magnetic isolation hole c. The angles between the magnetic isolation hole a, the magnetic isolation hole b, and the magnetic isolation hole c and the magnetic steel groove 2 on this side are α1, α2, and α3 respectively, and the angle between the magnetic isolation hole located on the d-axis and the magnetic steel groove 2 is b, then a1 > a2 > a3 ≥ b.

[0064] In a specific embodiment, as Figure 7 shown, the maximum gap L1 between the multiple magnetic isolation holes and the periphery of the motor rotor satisfies: L1 < L2, where L2 is the width of the magnetic isolation bridge between the magnetic steel groove 2 and the periphery of the rotor; the maximum gap L1 between the multiple magnetic isolation holes and the periphery of the motor rotor is less than the width of the magnetic isolation bridge between the magnetic steel groove 2 and the periphery of the rotor. In this way, the magnetic resistance at the periphery of the stator of the magnetic isolation holes will be relatively large, which can limit the magnetic force lines from directly passing through the edge of the rotor from the stator and directly returning to the stator, enabling more magnetic force lines to pass through the magnetic steel first and then return to the stator, thereby reducing the magnetic leakage of the motor and improving the effective utilization efficiency of the motor magnetic steel.

[0065] In a specific embodiment, the minimum width of the magnetic isolation hole is D1, and the width of the magnetic steel groove 2 is D2, then 0.3D2 ≤ D1 ≤ 0.6D2; this magnetic isolation hole structure can increase the demagnetization ability of the motor, increase the reliability of the motor operation, improve the performance of the motor to a certain extent, be equivalent to the performance of a larger motor in terms of performance, but use less materials and have a lower price. Therefore, it has a cost advantage on the premise of ensuring the reliability of the motor.

[0066] In a specific embodiment, both ends of the multiple magnetic isolation holes are arc-shaped or polygonal; that is to say, each magnetic isolation hole forming the magnetic isolation hole group 3 can be cylindrical, or a multi-prism structure such as a triangular prism or a quadrangular prism. However, no matter what structure it is, it needs to satisfy that the width of the second magnetic isolation hole 32 near the periphery of the motor rotor is less than the width away from the periphery of the motor rotor.

[0067] In a specific embodiment, the first magnetic isolation hole 31 may be a long strip hole with a constant width, or similar to the second magnetic isolation hole 32, and the width of the first magnetic isolation hole 31 decreases from far away from the periphery of the motor rotor to close to the periphery of the motor rotor.

[0068] The motor rotor provided in this embodiment sets magnetic barriers under each magnetic pole of the rotor through the structure of the two end points of the magnetic isolation hole on the circle, improves the magnetic density distribution under each magnetic pole of the rotor, reduces the magnetic density harmonic content in the air gap between the stator and rotor of the motor, and reduces the radial electromagnetic force and tangential electromagnetic force of high-order high multiple frequencies during the operation of the motor; after applying it to the motor, the vibration and noise during the operation of the motor can be reduced; after applying it to the compressor, the influence of the armature magnetic field of the motor on the magnetic field under the rotor magnetic pole under heavy load and high load conditions of the compressor can be reduced, and it can still operate safely under heavy load and high load conditions, increasing the demagnetization resistance of the motor.

[0069] Embodiment 2

[0070] This embodiment provides a motor, which includes the motor rotor of Embodiment 1; as Figure 8 shown, the motor further includes a stator 5, and the motor rotor is located inside the stator core.

[0071] In order to verify the performance of the motor provided in this embodiment, the radial electromagnetic force and tangential electromagnetic force of the motor in this embodiment are compared with those of a common conventional motor. The premise of the comparison is: the difference between the motor in this embodiment and the common conventional motor is only that: in the motor of this embodiment, the width of the second magnetic isolation hole 32 gradually decreases from the direction far away from the periphery of the motor rotor to the direction close to the periphery of the motor rotor, while the second magnetic isolation hole of the common conventional motor has a constant width. Except for this, the other parameters are the same; the comparison results are as Figure 10 shown, compared with the common conventional motor, the radial electromagnetic force of the motor provided in this embodiment has decreased by about 10%, and the tangential electromagnetic force has decreased by about 22%.

[0072] This embodiment applies the motor rotor in Embodiment 1 to the motor, improves the cogging torque and torque ripple, reduces the radial electromagnetic force and tangential electromagnetic force of each order and each multiple frequency during the operation of the motor, and thus improves the overall performance of the motor.

[0073] Embodiment 3

[0074] This embodiment provides a compressor, as Figure 9 shown, the compressor includes the motor of Embodiment 2.

[0075] In order to verify the noise of the compressor provided in this embodiment, the noise of the compressor provided in this embodiment is compared with that of a common conventional compressor. As Figure 11 shown is the total value noise change curve within 1.2K of the national standard. It can be seen from the figure that the noise of the compressor provided in this embodiment is significantly lower than that of the common conventional compressor.

[0076] In this embodiment, the motor in Embodiment 2 is applied to a compressor. By means of the structure where the two endpoints of the magnetic isolation holes are on a circle, magnetic barriers are arranged under each magnetic pole of the rotor, the magnetic flux density distribution under each magnetic pole of the rotor is improved, the harmonic content of the magnetic flux density in the air gap between the stator and rotor of the motor is reduced, and the radial electromagnetic force and tangential electromagnetic force of high-order high multiple frequencies during the operation of the motor are reduced, thereby reducing the vibration and noise during the operation of the motor. At the same time, the magnetic circuit under the magnetic poles of the rotor can be optimized, the influence of the armature magnetic field of the motor on the magnetic field under the magnetic poles of the rotor under heavy load and high load conditions of the compressor can be reduced, and it can still operate safely under heavy load and high load conditions, increasing the anti-demagnetization ability of the motor.

[0077] Embodiment 4

[0078] This embodiment provides an air conditioner, and the air conditioner includes the compressor of Embodiment 3.

[0079] In summary, it is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned advantageous technical features can be freely combined and superimposed.

[0080] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A motor rotor, characterized in that, It is formed by laminating a plurality of rotor punching sheets. The motor rotor includes a rotor core (1). The rotor core (1) has a plurality of magnetic poles. A magnet slot (2) is provided under the magnetic poles. A magnetic isolation hole group (3) is arranged on one side of the magnet slot (2) close to the periphery of the motor rotor. The magnetic isolation hole group (3) is symmetric about the d-axis of the motor rotor. A buckle point (4) for fixing the plurality of rotor punching sheets is arranged between the magnet slot (2) and the magnetic isolation hole group (3). The magnetic isolation hole group (3) includes a plurality of magnetic isolation holes, namely a first magnetic isolation hole (31) arranged on both sides and a second magnetic isolation hole (32) located between the two first magnetic isolation holes (31). At least one of the second magnetic isolation holes (32) satisfies that the width near the periphery of the motor rotor is smaller than the width far from the periphery of the motor rotor. Both ends of each second magnetic isolation hole (32) are arc-shaped. A plurality of arcs near the periphery of the motor rotor are all located on the circumference of a first circle, and a plurality of arcs far from the periphery of the motor rotor are all located on the circumference of a second circle, and R1≤R2, where R1 is the radius of the first circle and R2 is the radius of the second circle.

2. The motor rotor according to claim 1, wherein, The buckle points (4) are distributed on the center line of the magnetic poles.

3. The motor rotor according to claim 1, wherein, The buckle point (4) is rectangular. The length H of the buckle point (4) along the radial direction of the motor rotor satisfies: 2 mm ≤ H ≤ 4 mm. The width W of the buckle point (4) satisfies: 0.5 mm ≤ W ≤ 2 mm, and W ≤ H.

4. A motor rotor according to any one of claims 1-3, characterized in that, At least one of the second magnetic isolation holes (32) is strip-shaped, and the width of the second magnetic isolation hole (32) gradually decreases from the direction far from the periphery of the motor rotor to the direction close to the periphery of the motor rotor. The remaining second magnetic isolation holes (32) are of an equal-width structure.

5. A motor rotor according to any one of claims 1 to 3, characterized in that, At least one of the second magnetic isolation holes (32) includes at least two magnetic isolation hole segments (321). Each magnetic isolation hole segment (321) is a strip-shaped with equal width, and the width of adjacent magnetic isolation hole segments (321) decreases from the direction far from the periphery of the motor rotor to the direction close to the periphery of the motor rotor. The remaining second magnetic isolation holes (32) are of an equal-width structure.

6. A motor rotor according to any one of claims 1-3, characterized in that At least one of the second magnetic isolation holes (32) includes at least two magnetic isolation segments. Among all the magnetic isolation segments, from the direction far from the periphery of the motor rotor to the direction close to the periphery of the motor rotor, the width of at least one of the magnetic isolation segments decreases, and the rest are strip-shaped with equal width. The remaining second magnetic isolation holes (32) are of an equal-width structure.

7. The motor rotor according to claim 1, wherein, The arc shapes of both ends of each second magnetic isolation hole (32) satisfy: R3>R4, where R3 is the radius of the end arc far from the periphery of the motor rotor and R4 is the radius of the end arc close to the periphery of the motor rotor.

8. The motor rotor according to any one of claims 1 to 3, characterized in that, Along the direction from the center to both sides, the lengths of the plurality of magnetic isolation holes decrease in sequence.

9. The motor rotor according to claim 3, characterized in that, When there are 2n magnetic isolation holes, n of the magnetic isolation holes are located on one side of the d-axis, and the other n magnetic isolation holes are located on the other side of the d-axis; when there are 2n + 1 magnetic isolation holes, n of the magnetic isolation holes are located on one side of the d-axis, the other n magnetic isolation holes are located on the other side of the d-axis, and one magnetic isolation hole is located on the d-axis; where n is a natural number.

10. The motor rotor according to claim 9, characterized in that, When there are 2n + 1 magnetic isolation holes, if the length of the magnetic isolation hole located on the d-axis is H1, then 0 ≤ H1 / H ≤ 4.

11. The motor rotor according to claim 9, characterized in that, There is an included angle between the magnetic isolation holes on the same side of the d-axis and the magnetic steel groove (2) on that side, and the included angle decreases as the magnetic isolation hole gets closer to the d-axis.

12. The motor rotor according to claim 11, wherein, The included angle between the magnetic isolation hole located on the d-axis and the magnetic steel groove (2) is smaller than the included angle between any other magnetic isolation hole and the magnetic steel groove (2).

13. The motor rotor according to any one of claims 1-3, characterized in that, The maximum gap L1 between the multiple magnetic isolation holes and the outer periphery of the motor rotor satisfies: L1 < L2, where L2 is the width of the magnetic isolation bridge between the magnetic steel groove (2) and the outer periphery of the rotor.

14. The motor rotor according to any one of claims 1 to 3, characterized in that, The minimum width of the magnetic isolation hole is D1, and the width of the magnetic steel groove (2) is D2, then 0.3D2 ≤ D1 ≤ 0.6D2.

15. The motor rotor according to any one of claims 1 to 3, characterized in that, Both ends of the multiple magnetic isolation holes are arc-shaped or polygonal.

16. A motor, characterized in that, The motor includes the motor rotor according to any one of claims 1 - 15.

17. A compressor, characterized in that, The compressor includes the motor according to claim 16.

18. An air conditioner, characterized in that, The air conditioner includes the compressor according to claim 17.

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