A rotor assembly, electric machine and compressor

Abstract

The application provides a rotor assembly, a motor and a compressor, and the rotor assembly comprises a rotor core, a circumferential surface of the rotor core is a projection surface, a plurality of magnetic poles are arranged on the rotor core, a magnetic steel slot is arranged on each magnetic pole, and a magnetic steel is arranged in the magnetic steel slot; a plurality of grooves are arranged on an outer circle of the rotor core, in a radial direction of the rotor core, two adjacent magnetic poles have an adjacent area, and the groove is located on a radial outer side of the adjacent area; two ends of the magnetic steel slot extend to the outer circle of the rotor core, a magnetic isolation bridge is formed between a bottom wall of the groove and an outer edge of the magnetic steel slot, and a magnetic isolation hole is arranged on a radial outer side of the magnetic steel slot. When the rotor core is simultaneously provided with the groove and the magnetic isolation hole, the magnetic circuit direction of the center and the surrounding of the magnetic pole can be simultaneously optimized based on the structure, the current utilization rate of each frequency band of the motor is improved, and the problem of unstable rotation caused by electromagnetic force of the rotor with a small air gap can be solved.

Description

Technical Field

[0001] This invention belongs to the field of compressor technology, specifically relating to a rotor assembly, a motor, and a compressor. Background Technology

[0002] With the revision of domestic energy efficiency standards, improving the energy efficiency of air conditioners has become an important research task in the industry. The compressor is the heart of the air conditioning refrigeration system, and its energy efficiency improvement is crucial to the overall energy efficiency improvement of the air conditioning refrigeration system. Currently, one of the traditional design ideas for improving compressor efficiency is to reduce the air gap to increase the back electromotive force of the motor, thereby reducing the current during motor operation and improving the motor efficiency at various operating points by reducing copper losses and temperature rise.

[0003] However, reducing the air gap in a motor significantly increases the air gap magnetic flux density. Existing small-air-gap rotors are often insufficient to overcome this magnetic force and rotate smoothly, frequently resulting in eccentricity during operation. This leads to fluctuations in various motor parameters, such as torque, current, and electromotive force, reducing current utilization and hindering efficient motor operation. In some cases, motor step loss can even prevent the compressor from starting properly. Therefore, it is necessary to improve the operational stability and energy efficiency of small-air-gap rotor motors by addressing both the rotor structure and the magnetic circuit structure. Summary of the Invention

[0004] This invention provides a rotor assembly, a motor, and a compressor, which can solve the technical problem of low current utilization rate when using a rotor with a small air gap.

[0005] This invention provides a rotor assembly, including a rotor core. With the circumferential surface of the rotor core as the projection plane, the rotor core has multiple magnetic poles distributed circumferentially along the rotor core, and each magnetic pole has a magnetic slot containing a magnet. The outer circumference of the rotor core has multiple grooves. In the radial direction of the rotor core, adjacent magnetic poles have adjacent regions, and the grooves are located radially outside these adjacent regions. Both ends of the magnetic slots extend towards the outer circumference of the rotor core, and a magnetic isolation bridge is formed between the bottom wall of the groove and the outer edge of the magnetic slot. Magnetic isolation holes are provided radially outside the magnetic slots.

[0006] In some embodiments, the magnetic groove is V-shaped or straight, and at least one of the magnetic isolation holes is provided on the radial outer side of the magnetic groove.

[0007] In some embodiments, the magnetic groove is V-shaped, and the magnetic isolation hole is provided on the radial outer side of the magnetic groove; the central axis of the magnetic pole is the d-axis, and the geometric center of the magnetic isolation hole is located on the d-axis.

[0008] In some embodiments, the bottom wall of the groove is arc-shaped, and the first circle corresponding to the bottom wall of the groove is concentric with the center of the rotor core; or the bottom wall of the groove is straight, and the first circle tangent to the bottom wall of the groove is concentric with the center of the rotor core.

[0009] The diameter of the first circle is D1, the outer diameter of the rotor core is D0, the opening of the magnet slot faces the outer circle of the rotor core in the radial direction, the intersection of the two radial outer sides of the magnet slot is the vertex point, and the vertex point is located on the d-axis.

[0010] The distance from the vertex point to the outer circle of the rotor core is L0, and the distance L0 satisfies: 0.15 ≤

[0011]

[0012] In some embodiments, the depth of the groove in the radial direction of the rotor core is h. The depth h satisfies: 1.5 ≤ h ≤ 2.

[0013] In some embodiments, the radial length of the magnetic isolation hole is L1 in the radial direction of the rotor core, and the distance L0 and the radial length L1 satisfy:

[0014] In some embodiments, the magnetic steel groove is in the shape of a straight line, and two magnetic isolation holes are provided on the radial outer side of the magnetic steel groove. The two magnetic isolation holes are symmetrically arranged on both sides of the d-axis. The dividing line between two adjacent magnetic poles is the q-axis, and there is an angle between the d-axis and the q-axis. The magnetic isolation holes are located on the angle bisector of the angle.

[0015] In some embodiments, the bottom wall of the groove is arc-shaped, and the first circle corresponding to the bottom wall of the groove is concentric with the center of the rotor core; or the bottom wall of the groove is straight, and the first circle tangent to the bottom wall of the groove is concentric with the center of the rotor core.

[0016] The diameter of the first circle is D1, the outer diameter of the rotor core is D0, and the distance from the outer radial side of the magnet slot to the outer circle of the rotor core in the radial direction of the rotor core is L0, wherein the distance L0 satisfies:

[0017] In some embodiments, on the angle bisector of the included angle, the distance from the radially outer side of the magnetic slot to the outer circle of the rotor core is L0', and the radial length of the magnetic isolation hole is L1'. The distance L0' and the radial length L1' satisfy:

[0018] An electric motor includes a rotor assembly, wherein the rotor assembly is the rotor assembly described above.

[0019] A compressor comprising the aforementioned motor or the aforementioned rotor assembly.

[0020] The rotor assembly, motor, and compressor provided by this invention have the following beneficial effects:

[0021] The groove design of this invention allows the magnetic bridge to be positioned appropriately closer to the center of the rotor core, increasing the rotor core's rotational inertia without affecting its mechanical strength. By placing the groove, the magnetic bridge is positioned close to it, optimizing the air gap magnetic flux density and thus improving the current utilization rate of the motor across all frequency bands. Especially for rotors with small air gaps, the magnetic isolation holes optimize the magnetic circuit orientation near them, helping to solve the problem of unstable rotation caused by electromagnetic forces, improving the reliability of the compressor during startup, and also reducing noise. In this invention, when the rotor core is simultaneously equipped with grooves and magnetic isolation holes, this structure optimizes the magnetic circuit orientation of the magnetic pole center and its surroundings, reducing torque and current fluctuations, improving the current utilization rate of the motor across all frequency bands, and solving the problem of unstable rotation caused by electromagnetic forces in rotors with small air gaps. Attached Figure Description

[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the rotor core when the magnet slot is V-shaped, according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the distance L0, diameter D0, and diameter D1 when the magnetic groove is V-shaped according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the distance L0 and radial length L1 when the magnetic groove is V-shaped according to an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the magnet being installed when the magnet slot is V-shaped, according to an embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram of the rotor core when the magnet slot is in a straight line shape, according to an embodiment of the present invention.

[0028] Figure 6This is a schematic diagram of the distance L0, diameter D0, and diameter D1 when the magnetic steel groove is in the shape of a straight line according to an embodiment of the present invention.

[0029] Figure 7 This is a schematic diagram of the distance L0 and radial length L1 when the magnetic steel groove is in a straight line according to an embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram of the magnet being installed when the magnet slot is in the shape of a straight line, according to an embodiment of the present invention.

[0031] Figure 9 This is a comparison chart of motor efficiency in an embodiment of the present invention.

[0032] Attached Figure: 1-Rotor core; 2-Magnetic slot; 201-Peak point; 3-Magnet; 301-First circle; 4-Adjacent area; 5-Magnetic bridge; 6-Magnetic hole; 7-Shoulder; 8-Angle bisector of the included angle; 9-Groove. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0035] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0036] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0037] See also Figure 1 and Figure 5 As shown, according to an embodiment of the present invention, a rotor assembly is provided, including a rotor core 1. With the circumferential surface of the rotor core 1 as the projection plane, the rotor core 1 has multiple magnetic poles, each magnetic pole is distributed along the circumference of the rotor core 1, and each magnetic pole is constructed with a magnetic steel groove 2, in which a magnet 3 is disposed. The outer circle of the rotor core 1 is provided with multiple grooves 9. In the radial direction of the rotor core 1, two adjacent magnetic poles have adjacent regions 4, and the grooves 9 are located radially outside the adjacent regions 4. The two ends of the magnetic steel grooves 2 extend toward the outer circle of the rotor core 1, and a magnetic isolation bridge 5 is formed between the bottom wall of the groove 9 and the outer edge of the magnetic steel groove 2. Magnetic isolation holes 6 are provided radially outside the magnetic steel grooves 2.

[0038] Specifically, each pair of adjacent magnetic poles has an adjacent region 4, and the groove 9 is located radially outside the adjacent region 4. Since both ends of the magnetic steel groove 2 extend towards the outer circle of the rotor core 1, each end of the magnetic steel groove 2 corresponds to a groove 9. In the radial direction of the rotor core 1, the groove 9 is recessed towards the center of the rotor core 1. That is, by setting the groove 9, the outer circle of the rotor core 1 is brought closer to the magnetic steel groove 2, so that a magnetic bridge 5 is formed between the bottom wall of the groove 9 and the outer edge of the magnetic steel groove 2.

[0039] In this embodiment, the groove 9 allows the magnetic bridge 5 to be positioned appropriately closer to the center of the rotor core 1, increasing the rotational inertia of the rotor core 1 without affecting its mechanical strength. By setting the groove 9 so that the magnetic bridge 5 is close to the groove 9, the air gap magnetic flux density can be optimized, thereby improving the current utilization rate of the motor in all frequency bands. Especially for rotors with small air gaps, the setting of the magnetic isolation hole 6 optimizes the magnetic circuit orientation near the magnetic isolation hole 6, helping to solve the problem of unstable rotation caused by electromagnetic force, improving the reliability of the compressor during startup, and also reducing noise.

[0040] In this embodiment, when the rotor core 1 is provided with both groove 9 and magnetic isolation hole 6, the magnetic circuit direction of the magnetic pole center and the surrounding area can be optimized simultaneously based on this structure, reducing torque and current fluctuations, improving the current utilization rate of the motor in each frequency band, and solving the problem of unstable rotation caused by electromagnetic force in rotors with small air gaps.

[0041] As a specific implementation, the rotor core 1 is made of laminations and has 2p = 6 magnetic poles arranged circumferentially, where p is the number of pole pairs.

[0042] In one specific implementation, the outer circumference of the rotor core 1 is provided with multiple grooves 9. In addition, the outer circumference of the rotor core 1 in this embodiment does not have slots or chamfered edges. Furthermore, the grooves 9 are symmetrically arranged relative to adjacent areas 4, meaning that the area occupied by each groove 9 is the same at each magnetic pole. This can also be understood as a groove 9 being provided at each magnetic pole, with adjacent grooves 9 being connected. Existing rotor cores 1 typically have irregularly shaped chamfered edges on their outer circumference. This results in an irregular overall shape of the rotor core 1, making it difficult to locate the starting point during motor operation, thus causing the rotor to lose synchronization. The arrangement in this embodiment, while achieving the beneficial effects of the grooves 9, helps with motor positioning during startup, thereby avoiding loss of synchronization during rotor operation. It also facilitates positioning during assembly, effectively avoiding rotor eccentricity and solving the problem of eccentricity in the small air gap motor body structure, as well as the loss of synchronization during actual assembly and startup.

[0043] See also Figure 1 and Figure 5 As shown, the magnetic steel groove 2 is V-shaped or straight, and at least one magnetic isolation hole 6 is provided on the radial outer side of the magnetic steel groove 2.

[0044] Specifically, each magnetic pole is provided with only one magnetic steel groove 2, which can be either V-shaped or V-shaped. When the magnetic steel groove 2 is V-shaped, two magnets 3 are provided in the magnetic steel groove 2; when the magnetic steel groove 2 is straight, one magnet 3 is provided in the magnetic steel groove 2. Due to the different shapes of the grooves 9, at least one magnetic isolation hole 6 is provided on the radial outer side of the groove 9.

[0045] In this embodiment, regardless of whether the magnet slot 2 is V-shaped or straight, both ends of the magnet slot 2 have corresponding grooves 9, and magnetic isolation holes 6 are provided on the radial outer side of the magnet slot 2. Based on the different shapes of the magnet slot 2, the distance from the magnet slot 2 to the outer circle of the rotor core 1 is also different, and the magnetic circuit direction is also different. The number of magnetic isolation holes 6 can be flexibly selected according to the shape of the magnet slot 2.

[0046] See also Figures 1 to 4 As shown, the magnetic steel groove 2 is V-shaped, and a magnetic isolation hole 6 is provided on the radial outer side of the magnetic steel groove 2; the central axis of the magnetic pole is the d-axis, and the geometric center of the magnetic isolation hole 6 is located on the d-axis.

[0047] In this embodiment, when the magnet slot 2 is V-shaped, a magnetic isolation hole 6 is provided on the radial outer side of the magnet slot 2, and the geometric center of the magnetic isolation hole 6 is located on the d-axis. Because the distance between the end of the magnet slot 2 closest to the rotor core 1 and the outer circle of the rotor core 1 is relatively large, and the two magnets 3 of the magnet slot 2 are separated by the shoulder 7, the direction of the central magnetic path of each set of magnet slots 2 changes. Therefore, a magnetic isolation hole 6 needs to be provided on the d-axis to improve the magnetic path direction, enhance the magnetic focusing effect at the center line, thereby increasing magnetic resistance and reducing magnetic leakage.

[0048] As a specific implementation, when the magnetic groove 2 is V-shaped, it is preferable to provide one magnetic isolation hole 6. In other embodiments, under the premise of meeting the performance and magnetic circuit direction, two magnetic isolation holes 6 can also be provided on the d-axis.

[0049] See also Figures 1 to 4 As shown, the bottom wall of the groove 9 is arc-shaped, and the first circle 301 corresponding to the bottom wall of the groove 9 is concentrically set with the center of the rotor core 1; or the bottom wall of the groove 9 is straight, and the first circle 301 tangent to the bottom wall of the groove 9 is concentrically set with the center of the rotor core 1; the diameter of the first circle 301 is D1, the outer diameter of the rotor core 1 is D0, and in the radial direction of the rotor core 1, the opening of the magnet slot 2 faces the outer circle of the rotor core 1. The intersection of the two radial outer sides of the magnet slot 2 is the apex point 201, which is located on the d-axis; the distance from the apex point 201 to the outer circle of the rotor core 1 is L0, and the distance L0 satisfies:

[0050] In this embodiment, the groove 9 is generally rectangular. The bottom wall of the groove 9 can be either curved or straight. Neither structure has a significant impact on the performance improvement of this solution. However, considering the ease of processing, the curved shape is preferred. Since the distance between the bottom wall of the groove 9 and the outer edge of the magnet slot 2 determines the width of the magnetic bridge 5, based on the structural characteristics of the groove 9, the distance L0 from the apex point 201 to the outer circle of the rotor core 1 is limited, taking the first circle 301 as a reference. If the groove 9 is too deep, it will increase the magnetic density around the magnetic bridge 5, increase magnetic leakage, cause rotor demagnetization, and reduce the strength of the rotor core 1, making it difficult to process. In order to ensure that different models of motors can achieve the effect of setting the groove 9, this embodiment combines the V-shaped magnet slot 2 with a larger distance to the outer circle of the rotor core 1. By limiting the ratio of the depth of the groove 9 to the distance to the outer circle of the rotor core 1, the distance L0 is within this range, and the groove 9 has the best effect on improving the efficiency of the motor.

[0051] See also Figures 1 to 4 As shown, the depth of the groove 9 in the radial direction of the rotor core 1 is h. The depth h satisfies: 1.5 ≤ h ≤ 2.

[0052] In this embodiment, the depth of the groove 9 determines the width of the magnetic isolation bridge 5 and the strength of the rotor core 1. If the groove 9 is too large, it will cause a significant increase in the magnetic flux density and leakage flux around the magnetic isolation bridge, resulting in demagnetization of the rotor core 1. If it is too small, the motor performance optimization effect will not be obvious. The depth h is within this range, which will not affect the stiffness of the rotor core 1, can optimize the magnetic circuit around the magnetic isolation bridge 5, thereby changing the air gap magnetic flux density and improving the current utilization rate of the motor in each frequency band.

[0053] See also Figures 1 to 4 As shown, in the radial direction of the rotor core 1, the radial length of the magnetic isolation hole 6 is L1, and the distance L0 and the radial length L1 satisfy:

[0054] In this embodiment, the magnetic isolation hole 6 is a strip-shaped hole. If the length of the magnetic isolation hole 6 is too long, it will cause the magnetic flux density around the magnetic isolation hole 6 to be too saturated, resulting in magnetic leakage. It will also reduce the effective area of ​​the rotor core 1 in the magnetic isolation hole 6. During the processing and stacking of the magnetic isolation hole 6, the rotor core 1 is prone to deformation. The radial length L1 of the magnetic isolation hole 6 is within this range. This can optimize the magnetic circuit direction, increase the magnetic reluctance and enhance the magnetic focusing effect, while avoiding the magnetic circuit being too saturated, which would cause the motor magnetic flux density to be too high and the motor magnetic leakage to increase.

[0055] See also Figures 5 to 8 As shown, the magnetic steel groove 2 is in the shape of a straight line. Two magnetic isolation holes 6 are provided on the radial outer side of the magnetic steel groove 2. The two magnetic isolation holes 6 are symmetrically arranged on both sides of the d-axis. The dividing line between two adjacent magnetic poles is the q-axis. There is an angle between the d-axis and the q-axis. The magnetic isolation holes 6 are located on the angle bisector 8 of the angle.

[0056] In this embodiment, the magnet 3 of the straight-line magnet slot 2 is usually an integral structure. The magnet 3 may also adopt a spliced ​​structure, but the magnet 3 after actual assembly is still an integral unit. Moreover, the distance from the geometric center of the straight-line magnet slot 2 to the outer circle of the rotor core 1 is smaller than that of the V-shaped magnet slot 2. If a magnetic isolation hole 6 is set on the d-axis, it will cause the magnetic circuit at the d-axis to be too saturated, which will easily increase the leakage flux of the motor and be detrimental to the motor's operating efficiency. To avoid this problem, in this embodiment, each magnetic pole has two angle bisectors, and a magnetic isolation hole 6 is set on each angle bisector. In this way, the magnetic circuit can be optimized for the straight-line magnet slot 2.

[0057] See also Figures 5 to 8 As shown, the bottom wall of the groove 9 is arc-shaped, and the first circle 301 corresponding to the bottom wall of the groove 9 is concentrically set with the center of the rotor core 1; or the bottom wall of the groove 9 is straight, and the first circle 301 tangent to the bottom wall of the groove 9 is concentrically set with the center of the rotor core 1; the diameter of the first circle 301 is D1, the outer diameter of the rotor core 1 is D0, and in the radial direction of the rotor core 1, the distance from the radial outer edge of the magnetic slot 2 to the outer circle of the rotor core 1 is L0, and the distance L0 satisfies:

[0058] In this embodiment, when the magnet slot 2 is straight, the shape of the groove 9 remains unchanged. However, since the straight magnet slot 2 is close to the outer circle of the rotor core 1, based on the structural characteristics of the groove 9 and with the first circle 301 as a reference, the distance L0 from the radial outer edge of the magnet slot 2 to the outer circle of the rotor core 1 is limited. If the groove 9 is too deep, it will increase the magnetic density around the magnetic isolation bridge 5, increase magnetic leakage, cause rotor demagnetization, and reduce the strength of the rotor core 1, making it difficult to process. In order to ensure that different models of motors can achieve the effect of setting the groove 9, this embodiment combines the straight magnet slot 2 with a smaller distance from the outer circle of the rotor core 1. By limiting the ratio of the depth of the groove 9 to the distance from the outer circle of the rotor core 1, the distance L0 is within this range, and the groove 9 has the best effect on improving the efficiency of the motor.

[0059] See also Figures 5 to 8 As shown, on the angle bisector 8 of the included angle, the distance from the outer radial side of the magnetic slot 2 to the outer circle of the rotor core 1 is L0', and the radial length of the magnetic isolation hole 6 is L1'. The distance L0' and the radial length L1' satisfy:

[0060] In this embodiment, when the magnetic slot 2 is in the shape of a straight line, each magnetic pole is actually provided with two magnetic isolation holes 6. By limiting the ratio between the depth of the groove 9 and the distance to the outer circle of the rotor core 1, this limitation helps to reduce the torque pulsation of the rotor during operation, thereby reducing electromagnetic vibration and noise, and improving the energy efficiency of the motor. At the same time, it can also ensure the strength of the rotor magnetic isolation hole 6 and avoid processing deformation.

[0061] It is worth noting that although two types of magnet slots 2 can be used in this embodiment, the V-shaped magnet slot 2 is preferred. When the magnet slot 2 is V-shaped, the effective area of ​​the magnet 3 is larger, and for the same model of motor, the back electromotive force increases. In the field of motors, using V-shaped magnets 3 can effectively improve the operating efficiency of the motor compared to straight-line magnets. When the magnet slot 2 is V-shaped, the outer circle of the rotor core 1 is provided with grooves 9 and the radial outer side of the magnet slot 2 is provided with magnetic isolation holes 6, which significantly improves the motor efficiency. In addition, when the magnet slot 2 is V-shaped, the q-axis inductance of the motor is larger than that of the straight-line magnet slot 2, which increases the saliency ratio of the motor and helps to improve the reluctance torque. The increase in reluctance torque means higher torque density and better power performance.

[0062] An electric motor includes a rotor assembly, wherein the rotor assembly is the aforementioned rotor assembly.

[0063] See also Figure 9 As shown, when the outer circumference of the rotor core 1 is provided with a groove 9 and the radial outer side of the magnet slot 2 is provided with a magnetic isolation hole 6, the motor can achieve better motor efficiency. If only one of the two is provided, the improvement in motor efficiency will not be significant, especially when only the groove 9 is provided, it may even lead to a decrease in motor efficiency. Therefore, in this embodiment, the groove 9 is provided on the outer circumference of the rotor core 1 and the magnetic isolation hole 6 is provided on the radial outer side of the magnet slot 2. This can simultaneously optimize the magnetic circuit orientation of the magnetic pole center and its surroundings, reduce torque and current fluctuations, improve the current utilization rate of the motor in each frequency band, and solve the problem of unstable rotation caused by electromagnetic force.

[0064] A compressor comprising the aforementioned motor or the aforementioned rotor assembly.

[0065] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A rotor assembly comprising a rotor core (1), characterized in that, The rotor core (1) has a plurality of magnetic poles in a circumferential surface of the rotor core (1), each of the magnetic poles is distributed along the circumferential surface of the rotor core (1), and each of the magnetic poles is configured with a magnetic steel slot (2), and the magnetic steel slot (2) is provided with a magnetic steel (3); A plurality of grooves (9) are arranged on the outer circle of the rotor core (1), and in the radial direction of the rotor core (1), two adjacent magnetic poles have an adjacent area (4), and the grooves (9) are located on the radial outside of the adjacent area (4); the two ends of the magnetic steel slot (2) respectively extend to the outer circle of the rotor core (1), and the bottom wall of the groove (9) and the outer edge of the magnetic steel slot (2) form a magnetic isolation bridge (5); The magnetic steel slot (2) is in a V shape or a straight line shape, and at least one magnetic isolation hole (6) is arranged on the radial outside of the magnetic steel slot (2); When the magnetic steel slot (2) is V-shaped, the bottom wall of the groove (9) is arc-shaped, a first circle (301) corresponding to the bottom wall of the groove (9) is concentrically arranged with the center of the rotor core (1); or the bottom wall of the groove (9) is a straight line, a first circle (301) tangent to the bottom wall of the groove (9) and the center of the rotor core (1) are concentrically arranged; the diameter of the first circle (301) is D1, the diameter of the outer circle of the rotor core (1) is D0, in the radial direction of the rotor core (1), the opening of the magnetic steel slot (2) faces the outer circle of the rotor core (1), the intersection of the two radial outer sides of the magnetic steel slot (2) is a top corner point (201), and the top corner point (201) is located on the d-axis; the distance from the top corner point (201) to the outer circle of the rotor core (1) is L0, and the distance L0 satisfies: ; When the magnetic steel slot (2) is in a linear shape, two magnetic isolation holes (6) are arranged on the radial outer side of the magnetic steel slot (2), the bottom wall of the groove (9) is arc-shaped, and a first circle (301) corresponding to the bottom wall of the groove (9) is concentrically arranged with the center of the rotor core (1); or the bottom wall of the groove (9) is a straight line, a first circle (301) tangent to the bottom wall of the groove (9) is concentrically arranged with the center of the rotor core (1); the diameter of the first circle (301) is D1, the outer diameter of the rotor core (1) is D0, and in the radial direction of the rotor core (1), the distance from the radial outer side of the magnetic steel slot (2) to the outer circle of the rotor core (1) is L0, and the distance L0 satisfies: .

2. The rotor assembly of claim 1, wherein The magnetic steel slot (2) is in a V shape, the magnetic isolation hole (6) is arranged on the radial outside of the magnetic steel slot (2); the center axis of the magnetic pole is a d-axis, and the geometric center of the magnetic isolation hole (6) is located on the d-axis.

3. The rotor assembly of claim 1, wherein The magnetic steel slot (2) is V-shaped, in the radial direction of the rotor core (1), the depth of the groove (9) is h, h= , the depth h satisfies: .

4. The rotor assembly of claim 1, wherein The magnetic steel slot (2) is V-shaped, and the radial length of the magnetic isolation hole (6) is L1 in the radial direction of the rotor core (1), and the distance L0 and the radial length L1 satisfy: .

5. The rotor assembly of claim 1, wherein The magnetic steel slot (2) is in a straight line shape, and two magnetic isolation holes (6) are symmetrically arranged on both sides of the d-axis; the boundary line of two adjacent magnetic poles is a q-axis, the d-axis and the q-axis have an included angle, and the magnetic isolation hole (6) is located on the angle bisector (8) of the included angle.

6. The rotor assembly of claim 5, wherein The magnetic steel slot (2) is in a linear type, on the angle bisector (8) of the included angle, the distance from the radial outer side of the magnetic steel slot (2) to the outer circle of the rotor core (1) is L0` and the radial length of the magnetic isolation hole (6) is L1`, the distance L0` and the radial length L1` satisfy: .

7. An electric machine comprising a rotor assembly, characterized by The rotor assembly is the rotor assembly of any one of claims 1 to 6.

8. A compressor characterized by, The motor comprises the rotor assembly of claim 7, or the rotor assembly of any one of claims 1 to 6.

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