Motors, compressors and refrigeration equipment

Abstract

The present invention proposes a motor, a compressor and a refrigeration device. The motor includes: a rotor; a mounting groove, which is arranged on the rotor; a permanent magnet, which is arranged in the mounting groove and forms a magnetic pole, and the center line of any magnetic pole passing through the axis of the rotor is set as the D axis, wherein the distance between the intersection of the D axis and the outer edge of the rotor and the intersection of the D axis and a wall of the mounting groove close to the outer edge of the rotor is L1, and the minimum distance between the mounting groove and the outer edge of the rotor is L2, which satisfies 7≤L2 / L1×100≤9. The present invention can effectively improve the anti-demagnetization ability of the permanent magnet, avoid the risk of magnet demagnetization during the use of the motor, and reduce the number and frequency of maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a motor, a compressor and a refrigeration device. Background Art

[0002] For compressors used in refrigeration equipment such as air conditioners, variable-frequency motors have become the mainstream technology. Fixed-speed models have gradually withdrawn from the market, and full variable-frequency has arrived. At present, the motors of variable-frequency compressors are developing towards a multi-slot and multi-pole design structure. However, when the motor is running, the permanent magnet will be partially demagnetized, requiring frequent maintenance, which seriously affects the normal use of the motor. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0004] To this end, a first aspect of the present invention provides a motor.

[0005] A second aspect of the present invention provides a compressor.

[0006] A third aspect of the present invention provides a refrigeration device.

[0007] A first aspect of the present invention provides a motor, comprising: a rotor; a mounting groove, arranged on the rotor; a permanent magnet, arranged in the mounting groove and forming a magnetic pole, wherein the center line of any magnetic pole passing through the axis of the rotor is set as the D axis, wherein the distance between the intersection of the D axis and the outer edge of the rotor and the intersection of the D axis and a wall surface of the mounting groove close to the outer edge of the rotor is L1, and the minimum distance between the mounting groove and the outer edge of the rotor is L2, satisfying 7≤L2 / L1×100≤9.

[0008] The motor proposed in the present invention includes a rotor, a mounting slot and a permanent magnet. The mounting slot is arranged on the rotor and can provide a mounting position for the permanent magnet. The permanent magnet is arranged in the mounting slot and can form a magnetic pole in the rotor. In particular, the center line of any magnetic pole passing through the axis of the rotor is set as the D axis. There is an intersection between the D axis and the outer edge of the rotor. There is also an intersection between the D axis and a wall surface of the mounting slot close to the outer edge of the rotor. The distance between the two intersections is L1. The minimum distance between the mounting slot and the outer edge of the rotor is L2, and 7≤L2 / L1×100≤9 is satisfied.

[0009] In particular, in the demagnetized state, after the magnetic lines of force on the stator side reach the rotor, a small number of magnetic lines of force directly pass through the mounting slot and the permanent magnet, which will cause the remanence of the permanent magnet to decrease or produce local irreversible demagnetization, while most of the magnetic lines of force return to the stator. In addition, during the operation of the motor, after the magnetic field reaches the rotor, the magnetic lines of force will be offset. In particular, since the minimum distance L2 between the mounting slot and the outer edge of the rotor is small, the magnetic density gradually increases to saturation, and the ratio of the size L1 to the size L2 can reflect the speed of change of the path length magnetic permeability. It is worth noting that the size of L2 is generally constant at about 0.5mm, and the larger the size of L1, the greater the rate of change of the ratio of L1 to the size L2, which may cause a small number of magnetic lines of force to pass through the mounting slot. Therefore, the present invention designs the size of L1 to be smaller, so that L2 / L1 is larger than the related art, so that 7≤L2 / L1×100≤9. Based on the scheme defined in the present invention, the anti-demagnetization ability of the permanent magnet can be effectively enhanced, the risk of demagnetization of the motor during use can be effectively avoided, maintenance can be reduced, and the output torque and output capacity of the motor can be guaranteed.

[0010] That is, the present invention optimizes the shape and setting position of the installation groove, effectively improving the anti-demagnetization ability of the permanent magnet, which can effectively avoid the risk of magnet demagnetization during the use of the motor and reduce the number and frequency of maintenance.

[0011] The motor according to the above technical solution of the present invention may also have the following additional technical features:

[0012] In the above technical solution, the mounting groove includes: a first groove body; a second groove body, which is connected to the first groove body at the D axis, and the first groove body and the second groove body are distributed in a V shape.

[0013] In this technical solution, the mounting slot includes a first slot body and a second slot body. The first slot body is connected to the second slot body and is used to mount the permanent magnet. In addition, the first slot body and the second slot body are distributed in a V-shape, and the D axis is the axisymmetric line of the first slot body and the second slot body. That is, L1 defined in the present invention is the distance between the axisymmetric line of the first slot body and the second slot body, and the two intersection points of the outer edge of the rotor and a wall of the mounting slot close to the outer edge of the rotor.

[0014] In particular, the demagnetization area of ​​the stator includes the position where the first slot body and the second slot body are connected, that is, the sharp point of the V. For this reason, the present invention defines the D axis as the axisymmetric line of the first slot body and the second slot body, that is, the distance from the sharp point of the V to the outer edge of the rotor is guaranteed.

[0015] In any of the above technical solutions, the number of mounting grooves is 2P, and the 2P mounting grooves are distributed along the circumference of the rotor; the angular bisector of two adjacent D axes is the Q axis, the first groove body extends from the D axis toward the Q axis, and L2 is the minimum distance between the first groove body and the outer edge of the rotor.

[0016] In this technical solution, the number of mounting slots is 2P, and the 2P mounting slots are evenly distributed along the circumference of the rotor to form evenly distributed magnetic poles in the circumference of the rotor to ensure the smooth operation of the motor using the rotor. Specifically, P can be an integer such as 1, 2, 3, 4, 5, etc.

[0017] In addition, the angular bisector of two adjacent D axes is the Q axis. Along the circumferential direction of the rotor, the first slot body extends from the D axis toward the Q axis, and along the radial direction of the rotor, the first slot body extends from the axial direction of the rotor toward the outer edge. In addition, L2 is the minimum distance between the first slot body and the outer edge of the rotor, that is, L2 is the minimum distance between the first slot body and the outer edge of the rotor at the Q axis.

[0018] Specifically, in the demagnetized state, the reverse magnetic field generated at the stator, the magnetic lines of force pass through the stator teeth and the air gap to reach the rotor, causing the rotor to be demagnetized. After the magnetic lines of force on the stator side reach the rotor, a small number of magnetic lines of force directly pass through the mounting slots and permanent magnets, causing the remanence of the permanent magnets to decrease or produce local irreversible demagnetization, and most of the magnetic lines of force pass through the magnetic isolation bridge at the Q axis, through the air gap and return to the stator. The present invention designs the size of L1 to be smaller, so that 7≤L2 / L1×100≤9, thereby reducing the magnetic lines of force passing through the mounting slots and permanent magnets, allowing more magnetic lines of force to return to the stator, enhancing the stator's anti-demagnetization ability, and avoiding the risk of demagnetization of the motor during use.

[0019] In any of the above technical solutions, the motor also includes: a stator, on which a plurality of stator teeth are arranged, the tooth top walls of the plurality of stator teeth are collinear with the same stator inner circle, the diameter of the stator inner circle is Di, the width of the tooth top wall of the stator tooth is L3, satisfying 0.5≤2P×L3 / (π×Di)≤0.55.

[0020] In this technical solution, the motor also includes a stator, which can be used in conjunction with the rotor to output torque. The stator is provided with a plurality of stator teeth, the plurality of stator teeth extend toward the axis core of the stator, and the tooth top walls of the plurality of stator teeth are collinear with the same stator inner circle inside the stator. In particular, the diameter of the stator inner circle is Di, and the width of the tooth top wall of the stator tooth is L3, satisfying 0.5≤2P×L3 / (π×Di)≤0.55.

[0021] In particular, in the demagnetized state, the reverse magnetic field generated at the stator, the magnetic lines of force pass through the stator teeth and the air gap to reach the rotor, causing the rotor to demagnetize. After the magnetic field on the stator side reaches the rotor, a small number of magnetic lines of force directly pass through the mounting slots and permanent magnets, causing the permanent magnet remanence to drop or produce local irreversible demagnetization, and most of the magnetic lines of force pass through the magnetic isolation bridge at the Q axis, through the air gap and return to the stator.

[0022] Due to the existence of the stator slots, the span of the top of the stator teeth on the inner diameter of the stator (i.e., dimension L3) determines how many magnetic lines of force pass through the air gap to reach the rotor. According to simulation calculations, the size range of 0.5≤2P×L3 / (π×Di)≤0.55 is converged. A small proportion means that the slot is large, the tooth torque and torque pulsation are deteriorated, and the demagnetization is deteriorated; a large proportion means that more magnetic fields reach the rotor, and the demagnetization will also be deteriorated. Therefore, the present invention limits 0.5≤2P×L3 / (π×Di)≤0.55, so that 2P×L3 / (π×Di) is within a suitable range, ensuring that the risk of demagnetization of the permanent magnet is reduced.

[0023] In any of the above technical solutions, a straight line parallel to the D axis and at a distance of L3 / 2 from the D axis is set as the P axis, and the distance between the two intersection points of the P axis and the outer edge of the rotor and a wall of the mounting groove close to the outer edge of the rotor is L4, satisfying (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3).

[0024] In this technical solution, a straight line parallel to the D axis and at a distance of L3 / 2 from the D axis is set as the P axis. The P axis has an intersection with the outer edge of the rotor, and the P axis also has an intersection with a wall surface of the mounting groove close to the outer edge of the rotor. The distance between these two intersections is L4, and (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3) is satisfied.

[0025] It is worth noting that from L1 to L4, it can be considered that the magnetic lines of force coming from the stator side are gradually accepted and the magnetic permeance is gradually reduced. From L4 to L2, it is a process in which all the magnetic lines of force coming from the stator are gradually compressed and saturated (the magnetic permeance is gradually reduced), and the rate of change of the latter magnetic permeability is smaller than the rate of change of the former magnetic permeability. Among them, from L1 to L4, the width of the magnetic circuit changes from L1 to L4, and the length of the magnetic circuit changes from L3 / 2; from L4 to L2, the width of the magnetic circuit changes from L4 to L2, and the length of the magnetic circuit changes from (τ-L3) / 2, τ is the pole pitch, τ=π×Di1 / 2 / P. Therefore, after simplification, it can be obtained that (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3). Therefore, the present invention defines (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3), which can further enhance the anti-demagnetization ability of the stator and avoid the risk of demagnetization of the motor during use.

[0026] In any of the above technical solutions, the number of mounting slots 2P is 8 or 10; the number of stator teeth is 12.

[0027] In this technical solution, the number of mounting slots can be 8 or 10, and correspondingly, the number of stator teeth is 12. The motor with the above number of mounting slots and stator teeth has good anti-demagnetization capability and can effectively avoid demagnetization during use.

[0028] In any of the above technical solutions, L2 is greater than or equal to 0.5 mm.

[0029] In this technical solution, L2 is greater than or equal to 0.5 mm. By limiting L2 to be greater than or equal to 0.5 mm, the installation slot is set at a position on the rotor. Based on the above limitation, the motor has good anti-demagnetization capability and can effectively avoid demagnetization during use.

[0030] In any of the above technical solutions, an angle is formed between the first slot body and the second slot body, and the value range of the angle is 100° to 130°.

[0031] In this technical solution, an angle is formed between the first slot body and the second slot body, and the angle has a value range of 100° to 130°. In other words, the angle formed between the first slot body and the second slot body should be greater than or equal to 100° and less than or equal to 130°. Based on the size limit of the angle formed between the first slot body and the second slot body, it can be ensured that the structure of the mounting slot is appropriate, and at the same time, it can be ensured that the mounting slot is appropriately distributed in the circumferential direction of the rotor, and that an appropriate number of mounting slots are provided on the rotor. In addition, the anti-demagnetization ability of the rotor can be further improved, the demagnetization phenomenon can be improved, and the working efficiency and output capacity of the compressor can be ensured.

[0032] Specifically, the angle formed between the first trough body and the second trough body may be 100°, 105°, 110°, 115°, 120°, 125°, 130°, etc.

[0033] In any of the above technical solutions, a transition fillet is provided at the connection between the first slot body and the second slot body. The transition fillet is located on a wall surface of the mounting slot close to the outer edge of the rotor, and the radius is greater than or equal to 0.5 mm.

[0034] In this technical solution, the rotor also includes a transition fillet. The transition fillet is arranged at the position where the first slot body and the second slot body are connected, that is, at the sharp point of the V shape, and the transition fillet is located on a wall surface of the slot close to the outer edge of the rotor. The setting of the transition fillet can avoid the existence of a sharp point at the connection between the first slot body and the second slot body, and can avoid the situation of stress concentration at the connection between the first slot body and the second slot body.

[0035] A second aspect of the present invention provides a compressor, comprising: a motor as described in the first aspect of the present invention.

[0036] The compressor proposed by the present invention comprises the motor according to the first aspect of the present invention, and therefore has all the beneficial effects of the above-mentioned rotor, which will not be discussed one by one here.

[0037] A third aspect of the present invention provides a refrigeration device, comprising: a compressor as described in the second aspect of the present invention.

[0038] The refrigeration device proposed by the present invention comprises the compressor according to the second aspect of the present invention, and therefore, has all the beneficial effects of the above-mentioned rotor, which will not be discussed here one by one.

[0039] Specifically, the refrigeration equipment proposed by the present invention can be an air conditioner, a refrigerator, a freezer, a display cabinet, etc.

[0040] In any of the above technical solutions, the permanent magnet is arranged in the mounting groove to form a magnetic pole, and the permanent magnet does not contain heavy rare earth elements dysprosium and terbium.

[0041] In any of the above technical solutions, the D axis is also the middle symmetry line of the "V" shape, and the Q axis is also the symmetry line between two adjacent installation grooves.

[0042] In any of the above technical solutions, L1 is the distance between the intersection of the D axis and the outer edge of the rotor and the intersection of the mounting slot, L2 is the minimum gap between the mounting slot and the outer edge of the rotor near the Q axis, L3 is the distance between the intersection points on both sides of the stator teeth on the inner circle of the stator, and L4 is the distance between a straight line parallel to the D axis and at a distance of L3 / 2 from the D axis and the intersection of the outer edge of the rotor and the mounting slot.

[0043] In any of the above technical solutions, the mounting slot is a permanent magnet slot.

[0044] In any of the above technical solutions, there is no air magnetic isolation gap (slit) on the side of the mounting slot close to the outer edge of the rotor.

[0045] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention.

[0046] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0048] Figure 1 is a schematic structural diagram of a rotor in a motor according to an embodiment of the present invention;

[0049] Figure 2 for Figure 1 A partial enlarged view of the rotor at position A of the illustrated embodiment;

[0050] Figure 3 It is a schematic structural diagram of a stator in a motor according to an embodiment of the present invention.

[0051] in, Figures 1 to 3 The corresponding relationship between the reference numerals and the component names is as follows:

[0052] 102 rotor, 104 mounting slot, 1042 first slot body, 1044 second slot body, 106 stator, 108 stator teeth. DETAILED DESCRIPTION

[0053] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0055] Refer to the following Figures 1 to 3 The following describes a motor, a compressor and a refrigeration device provided according to some embodiments of the present invention.

[0056] Embodiment 1:

[0057] like Figure 1 and Figure 2 As shown, the first embodiment of the present invention provides a motor, comprising: a rotor 102, a mounting slot 104 and a permanent magnet. The mounting slot 104 is arranged on the rotor 102 and can provide a mounting position for the permanent magnet. The permanent magnet is arranged in the mounting slot 104 and can form a magnetic pole in the rotor 102.

[0058] Among them, Figure 1 As shown, the center line of any magnetic pole passing through the axis of the rotor 102 is set as the D axis. There is an intersection between the D axis and the outer edge of the rotor 102, and there is also an intersection between the D axis and a wall surface of the mounting groove 104 close to the outer edge of the rotor 102; Figure 2 As shown, the distance between the two intersection points is L1, the minimum distance between the mounting groove 104 and the outer edge of the rotor 102 is L2, and 7≤L2 / L1×100≤9 is satisfied.

[0059] In particular, in the demagnetized state, after the magnetic force lines on the stator 106 side reach the rotor 102, a small part of the magnetic force lines directly pass through the mounting slot 104 and the permanent magnet, which causes the residual magnetism of the permanent magnet to decrease or produce local irreversible demagnetization, while most of the magnetic force lines return to the stator 106. In addition, during the operation of the motor, after the magnetic field reaches the rotor 102, the magnetic force lines are offset.

[0060] In particular, since the minimum distance L2 between the mounting slot 104 and the outer edge of the rotor 102 is small, the magnetic flux density gradually increases to saturation, and the ratio of the size L1 to the size L2 can reflect the change speed of the path length magnetic permeability. It is worth noting that the size of L2 is generally constant at about 0.5 mm, and the larger the size of L1, the greater the rate of change of the ratio of L1 to size L2, which may cause a small part of the magnetic lines of force to pass through the mounting slot 104.

[0061] Therefore, in this embodiment, the size of L1 is designed to be smaller, so that L2 / L1 is larger than that of the related art, so that 7≤L2 / L1×100≤9. Based on the scheme defined in the present invention, the anti-demagnetization ability of the permanent magnet can be effectively enhanced, the demagnetization risk of the motor during use can be effectively avoided, maintenance can be reduced, and the output torque and output capacity of the motor can be guaranteed.

[0062] That is, this embodiment optimizes the shape and setting position of the installation groove 104, effectively improving the anti-demagnetization ability of the permanent magnet, which can effectively avoid the risk of magnet demagnetization during the use of the motor and reduce the number and frequency of maintenance.

[0063] In this embodiment, further, Figure 1 and Figure 2 As shown, the mounting slot 104 includes a first slot body 1042 and a second slot body 1044. The first slot body 1042 is connected to the second slot body 1044 and is used to mount the permanent magnet. In addition, the first slot body 1042 and the second slot body 1044 are distributed in a V shape, and the D axis is the axisymmetric line of the first slot body 1042 and the second slot body 1044. That is, L1 defined in this embodiment is the distance between the two intersections of the axisymmetric line of the first slot body 1042 and the second slot body 1044 and the outer edge of the rotor 102 and a wall of the mounting slot 104 close to the outer edge of the rotor 102.

[0064] In particular, the demagnetization area of ​​the stator 106 includes the position where the first slot body 1042 and the second slot body 1044 are connected, that is, the sharp point of the V. For this reason, the D axis is defined as the axisymmetric line of the first slot body 1042 and the second slot body 1044 in this embodiment, that is, the distance from the sharp point of the V to the outer edge of the rotor 102 is ensured.

[0065] In this embodiment, further, the number of the mounting slots 104 is 2P, and the 2P mounting slots 104 are evenly distributed along the circumference of the rotor 102 to form evenly distributed magnetic poles in the circumference of the rotor 102, ensuring the smooth operation of the motor using the rotor 102. Specifically, P can be an integer such as 1, 2, 3, 4, etc.

[0066] Furthermore, the angular bisector of two adjacent D axes is the Q axis, and along the circumferential direction of the rotor 102, the first slot body 1042 extends from the D axis toward the Q axis, and along the radial direction of the rotor 102, the first slot body 1042 extends from the axial direction toward the outer edge of the rotor 102. In addition, L2 is the minimum distance between the first slot body 1042 and the outer edge of the rotor 102, that is, L2 is the minimum distance between the first slot body 1042 and the outer edge of the rotor 102 at the Q axis.

[0067] Specifically, in the demagnetized state, the reverse magnetic field generated at the stator 106, the magnetic lines of force pass through the stator teeth 108 and the air gap to reach the rotor 102, causing the rotor 102 to be demagnetized. After the magnetic lines of force on the stator 106 side reach the rotor 102, a small part of the magnetic lines of force directly pass through the mounting slot 104 and the permanent magnet, causing the permanent magnet remanence to drop or produce local irreversible demagnetization, and most of the magnetic lines of force pass through the magnetic isolation bridge at the Q axis, through the air gap and return to the stator 106. The present invention designs the size of L1 to be smaller, so that 7≤L2 / L1×100≤9, thereby reducing the magnetic lines of force passing through the mounting slot 104 and the permanent magnet, allowing more magnetic lines of force to return to the stator 106, enhancing the anti-demagnetization ability of the stator 106, and avoiding the risk of demagnetization of the motor during use.

[0068] Embodiment 2:

[0069] like Figure 1 , Figure 2 and Figure 3 As shown, the second embodiment of the present invention provides a motor, including: a rotor 102, 2P mounting slots 104, a permanent magnet and a stator 106. The mounting slots 104 are arranged on the rotor 102 and can provide a mounting position for the permanent magnet. The permanent magnet is arranged in the mounting slots 104 and can form a magnetic pole in the rotor 102.

[0070] Among them, Figure 1 As shown, the center line of any magnetic pole passing through the axis of the rotor 102 is set as the D axis, and the angular bisector of two adjacent D axes is the Q axis. Figure 2 As shown, L1 is the distance between the two intersection points of the D axis and the outer edge of the rotor 102 and a wall of the mounting slot 104 close to the outer edge of the rotor 102, and L2 is the minimum distance between the first slot body 1042 and the outer edge of the rotor 102, and satisfies 7≤L2 / L1×100≤9.

[0071] In addition, if Figure 3As shown, the motor further includes a stator 106, which can be used in conjunction with the rotor 102 to output torque. The stator 106 is provided with a plurality of stator teeth 108, which extend toward the axis of the stator 106, and the tooth top walls of the plurality of stator teeth 108 are collinear with the same stator inner circle inside the stator 106. In particular, the diameter of the stator inner circle is Di, and the width of the tooth top wall of the stator tooth 108 is L3, which satisfies 0.5≤2P×L3 / (π×Di)≤0.55.

[0072] In particular, in the demagnetized state, the reverse magnetic field generated at the stator 106, the magnetic lines of force pass through the stator teeth 108 and the air gap to reach the rotor 102, causing the rotor 102 to be demagnetized. After the magnetic field on the stator 106 side reaches the rotor 102, a small part of the magnetic lines of force directly pass through the mounting slot 104 and the permanent magnet, causing the permanent magnet remanence to decrease or produce local irreversible demagnetization, and most of the magnetic lines of force pass through the magnetic isolation bridge at the Q axis, pass through the air gap and return to the stator 106.

[0073] Due to the presence of the stator 106 slot, the span (dimension L3) at the top of the stator tooth 108 on the inner diameter of the stator 106 determines how many magnetic lines of force pass through the air gap to reach the rotor 102. According to the simulation calculation, the size range of 0.5≤2P×L3 / (π×Di)≤0.55 is converged. If the proportion is too small, it means that the slot is large, the tooth torque and torque pulsation are deteriorated, and the demagnetization is deteriorated; if the proportion is too large, it means that more magnetic fields reach the rotor 102, and the demagnetization will also be deteriorated. Therefore, the present invention limits 0.5≤2P×L3 / (π×Di)≤0.55, so that 2P×L3 / (π×Di) is within a suitable range, ensuring that the risk of demagnetization of the permanent magnet is reduced.

[0074] In this embodiment, further, Figure 2 and Figure 3 As shown, a straight line parallel to the D axis and having a distance of L3 / 2 from the D axis is set as the P axis. The P axis has an intersection with the outer edge of the rotor 102, and the P axis also has an intersection with a wall surface of the mounting groove 104 close to the outer edge of the rotor 102. The distance between the two intersections is L4, and (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3) is satisfied.

[0075] It is worth noting that from L1 to L4, it can be considered that the magnetic lines of force coming from the stator 106 side are gradually accepted and the magnetic permeance is gradually reduced, and from L4 to L2, it is a process in which all the magnetic lines of force coming from the stator 106 are gradually compressed and saturated (the magnetic permeance is gradually reduced), and the rate of change of the latter magnetic permeance is smaller than the rate of change of the former magnetic permeability. Among them, from L1 to L4, the width of the magnetic circuit changes from L1 to L4, and the length of the magnetic circuit changes from L3 / 2; from L4 to L2, the width of the magnetic circuit changes from L4 to L2, and the length of the magnetic circuit changes from (τ-L3) / 2, τ is the pole pitch, τ=π×Di1 / 2 / P. Therefore, after simplification, it can be obtained that (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3). Therefore, the present invention defines (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3), which can further enhance the anti-demagnetization capability of the stator 106 and avoid the risk of demagnetization of the motor during use.

[0076] In addition, since the motor proposed in this embodiment also satisfies 7≤L2 / L1×100≤9, all the beneficial effects of the motor proposed in the first embodiment are achieved, which will not be discussed here one by one.

[0077] On the basis of the first and second embodiments, further, the number of the mounting slots 104 can be 8 or 10. Figure 3 As shown, the number of stator teeth 108 is 12. The motor with the above number of mounting slots 104 and stator teeth 108 has good anti-demagnetization capability and can effectively avoid demagnetization during use.

[0078] On the basis of the first and second embodiments, further, as Figure 2 As shown, L2 is greater than or equal to 0.5 mm. By limiting L2 to be greater than or equal to 0.5 mm, the installation slot 104 is also limited in the rotor 102. Based on the above limitation, the motor has good anti-demagnetization capability and can effectively avoid demagnetization during use.

[0079] On the basis of the first and second embodiments, further, as Figure 2As shown, an angle is formed between the first slot body 1042 and the second slot body 1044, and the angle has a value range of 100° to 130°. In other words, the angle formed between the first slot body 1042 and the second slot body 1044 should be greater than or equal to 100° and less than or equal to 130°. Based on the size limit of the angle formed between the first slot body 1042 and the second slot body 1044, it can be ensured that the structure of the mounting slot 104 is suitable, and at the same time, it can be ensured that the mounting slot 104 is appropriately distributed with the circumferential direction of the rotor 102, and that an appropriate number of mounting slots 104 are provided on the rotor 102. In addition, the anti-demagnetization ability of the rotor 102 can be further improved, the demagnetization phenomenon can be improved, and the working efficiency and output capacity of the compressor can be ensured.

[0080] Specifically, the angle formed between the first trough body and the second trough body may be 100°, 105°, 110°, 115°, 120°, 125°, 130°, etc.

[0081] On the basis of the first and second embodiments, further, as Figure 2 As shown, the rotor 102 further includes a transition fillet. The transition fillet is arranged at the position where the first slot body 1042 and the second slot body 1044 are connected, that is, at the sharp point of the V-shape, and the transition fillet is located on a wall surface of the slot close to the outer edge of the rotor 102. The provision of the transition fillet can avoid the presence of a sharp point at the connection between the first slot body 1042 and the second slot body 1044, and can avoid the presence of stress concentration at the connection between the first slot body 1042 and the second slot body 1044.

[0082] On the basis of the first and second embodiments, further, the permanent magnet is arranged in the installation groove 104 to form a magnetic pole, and the permanent magnet does not contain heavy rare earth elements dysprosium and terbium.

[0083] On the basis of the first and second embodiments, Figure 1 As shown, the D axis is also the middle symmetry line of the “V” shape, and the Q axis is also the symmetry line between the two mounting grooves 104 .

[0084] On the basis of the first and second embodiments, Figure 2 and Figure 3 As shown, L1 is the distance between the intersection of the D axis and the outer edge of the rotor 102 and the intersection of the mounting slot 104, L2 is the minimum gap between the mounting slot 104 and the outer edge of the rotor 102 near the Q axis, L3 is the distance between the intersections of the stator teeth 108 on both sides of the stator inner circle, and L4 is the distance between a straight line parallel to the D axis and at a distance of L3 / 2 from the D axis and the intersection of the outer edge of the rotor 102 and the mounting slot 104.

[0085] On the basis of the first and second embodiments, the mounting groove 104 is a permanent magnet groove.

[0086] Embodiment three:

[0087] A third embodiment of the present invention provides a compressor, comprising: a motor as in the first or second embodiment of the present invention (this embodiment is not shown in the figure).

[0088] The compressor proposed in this embodiment includes the motor of the first or second embodiment of the present invention, and therefore, has all the beneficial effects of the rotor 102, which will not be discussed here one by one.

[0089] Embodiment 4:

[0090] A fourth embodiment of the present invention provides a refrigeration device, comprising: a compressor as in the third embodiment of the present invention (this embodiment is not shown in the figure).

[0091] The refrigeration device proposed in this embodiment includes the compressor of the third embodiment of the present invention, and therefore, has all the beneficial effects of the rotor 102 as described above, which will not be discussed here one by one.

[0092] Specifically, the refrigeration equipment proposed in this embodiment can be an air conditioner, a refrigerator, a freezer, a display cabinet, etc. Specific embodiment:

[0094] In the compressors of existing household air conditioners and other household appliances, variable frequency motors have become the mainstream technology. Especially with the new energy efficiency rating standards for household air conditioners promulgated by the state in 2019, fixed speed models have gradually withdrawn from the market, and all variable frequency motors have arrived. In order to adapt to the application environment of household air conditioners, the permanent magnets of variable frequency motors are mostly NdFeB permanent magnets containing heavy rare earth elements and high coercivity. However, with the annual increase in the total number of variable frequency models, the consumption of heavy rare earth elements (especially dysprosium and terbium), which are national strategic resources, has also increased year by year. In order to reduce the consumption of strategic resources, application research on NdFeB permanent magnets without heavy rare earths is required.

[0095] The application of heavy rare earth-free permanent magnets needs to be combined with the multi-slot and multi-pole design structure of the motor. Due to the increase in the number of poles, the magnetic density of the yoke of the motor stator teeth 108 needs to be reduced accordingly to avoid excessive iron loss and reduced efficiency of the motor.

[0096] For this reason, Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides a motor and a compressor, wherein the motor comprises: a rotor 102, on which there are 2P mounting grooves 104, containing NdFeB permanent magnets, which do not contain heavy rare earth elements dysprosium and terbium; the mounting grooves 104 are V-shaped, such as Figure 2As shown, the middle symmetry line of the V-shape is the D axis, and the symmetry line between the two mounting grooves 104 is the Q axis; the distance between the intersection of the D axis and the outer edge of the rotor 102 and the intersection of the mounting groove 104 is L1, and the minimum gap between the mounting groove 104 and the outer edge of the rotor 102 near the Q axis is L2, 7≤L2 / L1×100≤9; Figure 3 As shown, the stator 106 has a stator inner circle and stator teeth 108 on the stator 106, the diameter of the stator inner circle is Di, and the distance between the intersection points on both sides of the stator teeth 108 at the stator inner circle is L3, 0.5≤2P×L3 / (π×Di)≤0.55; Figure 2 and Figure 3 As shown, the distance between the straight line parallel to the D axis and the distance L3 / 2 and the intersection of the outer edge of the rotor 102 and the slot of the rotor 102 is L4, (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3). According to the motor proposed in this embodiment, its anti-demagnetization ability is enhanced, which can effectively avoid the risk of magnet demagnetization during the use of the motor and reduce maintenance.

[0097] In addition, if Figure 1 As shown, the number of mounting slots 104 is 2P=8 or 10. Figure 3 As shown, the number of stator teeth 108 is 12; there is no air magnetic isolation gap (slit) on the side of the mounting slot 104 close to the outer edge of the rotor 102.

[0098] In a specific embodiment, in the demagnetization state, the reverse magnetic field generated at the stator 106 passes through the stator teeth 108 and the air gap to reach the rotor 102, causing the rotor 102 to be demagnetized. After the magnetic field on the stator 106 side reaches the rotor 102, a small part of the reverse magnetic field directly passes through the mounting slot 104 and the magnet, causing the residual magnetism of the magnet to decrease or causing local irreversible demagnetization, and most of the reverse magnetic field passes through the magnetic isolation bridge of the Q axis, passes through the air gap and returns to the stator 106.

[0099] Due to the existence of the stator 106 slot, the top of the stator tooth 108 and the span on the inner diameter of the stator 106 (dimension L3) determine how many magnetic lines of force pass through the air gap to reach the rotor 102. According to the simulation calculation, the size range of 0.5≤2P×L3 / (π×Di)≤0.55 is converged. If the proportion is too small, it means that the slot is too large, the tooth torque and torque pulsation are deteriorated, and the demagnetization is deteriorated. If the proportion is too large, it means that more magnetic fields reach the rotor 102, and the demagnetization will also be deteriorated.

[0100] After the magnetic field reaches the rotor 102, the magnetic lines of force are offset toward the Q axis. Since the width of the magnetic isolation bridge at the Q axis (dimension L2) is narrow, the magnetic density gradually increases to saturation. The ratio of dimension L1 to dimension L2 can reflect the speed of change of the path length magnetic permeability. The size of L2 is generally constant at about 0.5mm. The larger the size of L1, the greater the rate of change, which may cause a small number of magnetic lines of force to pass through the mounting slot 104. Therefore, if the size of L1 is designed to be smaller, L2 / L1 will increase compared with the existing size, 7≤L2 / L1×100≤9

[0101] It extends downward from the top of the stator tooth 108 to form a dimension L4. From L1 to L4, it can be considered that the magnetic lines of force coming from the stator 106 side are gradually accepted and the magnetic permeance is gradually reduced. From L4 to L2, it is a process in which all the magnetic lines of force coming from the stator 106 are gradually compressed and saturated (the magnetic permeance is gradually reduced), and the change rate of the latter magnetic permeance is smaller than the change rate of the former magnetic permeance.

[0102] From L1 to L4, the width of the magnetic circuit changes from L1 to L4, and the length of the magnetic circuit changes from L3 / 2; from L4 to L2, the width of the magnetic circuit changes from L4 to L2, and the length of the magnetic circuit changes from (τ-L3) / 2, τ is the pole pitch, τ=π×Di / 2 / P. So After simplification, we can obtain that (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3).

[0103] As shown in Table 1, the values ​​of L2 / L1*100, 2P×L3 / (π×Di), 2(L1-L4) / L3, and 2(L4-L2) / (τ-L3) of the motor proposed in the present invention are obviously different from those of the related art, thereby improving the anti-demagnetization capability of the motor. In Table 1, numbers 1 to 4 are parameters of the related art, and number 5 is a parameter of a specific embodiment of the present invention.

[0104] Table 1

[0105]

[0106] In the description of the present invention, the term "plurality" refers to two or more than two. Unless otherwise clearly defined, the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention. The terms "connection", "installation", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0107] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0108] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A motor, characterized in that: include: Rotor; A mounting groove is provided on the rotor; A permanent magnet is arranged in the installation groove and forms a magnetic pole, and a center line of any magnetic pole passing through the axis of the rotor is set as the D axis. The distance between the intersection of the D axis and the outer edge of the rotor and the intersection of the D axis and a wall of the mounting groove close to the outer edge of the rotor is L1, and the minimum distance between the mounting groove and the outer edge of the rotor is L2, satisfying 7≤L2 / L1×100≤9; The number of the installation slots is 2P; A stator is provided with a plurality of stator teeth, the tooth top walls of the plurality of stator teeth are collinear with the same stator inner circle, the diameter of the stator inner circle is Di, the width of the tooth top wall of the stator teeth is L3, and 0.5≤2P×L3 / (π×Di)≤0.55 is satisfied.

2. The motor according to claim 1, characterized in that The mounting slot comprises: A first tank body; The second slot body is connected to the first slot body at the D axis, and the first slot body and the second slot body are distributed in a V shape.

3. The motor according to claim 2, characterized in that 2P of the mounting grooves are distributed along the circumference of the rotor; The angular bisector of two adjacent D axes is the Q axis, the first slot body extends from the D axis toward the Q axis, and L2 is the minimum distance between the first slot body and the outer edge of the rotor.

4. The motor according to claim 3, characterized in that A straight line parallel to the D axis and at a distance of L3 / 2 from the D axis is set as the P axis, and a distance between two intersection points of the P axis and the outer edge of the rotor and a wall of the mounting groove close to the outer edge of the rotor is L4, satisfying (L1-L4) / L3≥(L4-L2) / (π×Di / 2P-L3).

5. The motor according to claim 3, characterized in that The number 2P of the installation slots is 8 or 10; The number of stator teeth is 12.

6. The electric machine according to any one of claims 1 to 5, characterized in that The L2 is greater than or equal to 0.5 mm.

7. The electric machine according to any one of claims 3 to 5, characterized in that An angle is formed between the first slot body and the second slot body, and a value range of the angle is 100° to 130°; and / or A transition fillet is provided at the connection point between the first slot body and the second slot body. The transition fillet is located on a wall surface of the mounting slot close to the outer edge of the rotor, and has a radius greater than or equal to 0.5 mm.

8. A compressor, characterized in that: include: A motor as claimed in any one of claims 1 to 7.

9. A refrigeration device, characterized in that: include: The compressor as claimed in claim 8.

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