Motor, compressor and refrigeration equipment

Abstract

The utility model discloses a motor, compressor and refrigeration equipment, relates to the motor technical field, the motor comprises a stator and a rotor, the stator has the minimum inner diameter D1, the stator comprises a stator iron core and a winding, the winding is wound on the stator teeth of the stator iron core, the number of turns of the winding is N, and the constant of the winding is a; the rotor is rotatably arranged in the stator so as to form an air gap delta between the stator and the rotor, the maximum outer diameter of the rotor is D2, delta = (D1-D2) / 2, the rotor comprises a rotor iron core and permanent magnets, the rotor iron core is provided with magnet grooves, magnetic bridges are formed between the magnet grooves and the outer periphery of the rotor iron core, the width of each magnetic bridge is t, the permanent magnets are arranged in the magnet grooves, and the width of each permanent magnet is t. The length of the permanent magnet is L, and (N * t) / (21.5 * a * delta * L2) is larger than or equal to 1.9 and smaller than or equal to 2.0; and when the windings are connected in series in a corner joint manner, a is equal to 1.732. According to the technical scheme provided by the utility model, the demagnetization current can be increased, and the anti-demagnetization capability is enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, and particularly relates to a motor, a compressor and a refrigeration device. Background Art

[0002] In the design of brushless permanent magnet motors, a major challenge is the design of the demagnetization resistance of the motor. During the use of brushless permanent magnet motors, the edge part of the permanent magnet in the motor rotor is affected by the magnetic field generated by the stator winding, and demagnetization is likely to occur, which seriously affects the overall magnetism of the permanent magnet, and thus affects the performance of the motor and shortens the service life of the motor. Summary of the Utility Model

[0003] The main object of the utility model is to provide a motor, a compressor and a refrigeration device, aiming to improve the demagnetization resistance of the motor.

[0004] To achieve the above object, the motor proposed by the utility model includes:

[0005] A stator, the stator includes a stator core and a winding, the minimum inner diameter of the stator is D 1 , the winding is wound around the stator teeth of the stator core, the number of turns of the winding is N, and the constant of the winding is a; and

[0006] A rotor, the rotor is rotatably arranged in the stator to form an air gap δ between the stator and the rotor, the maximum outer diameter of the rotor is D 2 , δ = (D 1 - D 2 ) / 2, the rotor includes a rotor core and a permanent magnet, the rotor core is provided with a magnet slot, a magnetic bridge is formed between the magnet slot and the outer peripheral edge of the rotor core, the width of the magnetic bridge is t, the permanent magnet is arranged in the magnet slot, the length of the permanent magnet is L, 1.9 ≤ (N × t) / (21.5 × a × δ × L 2 ) ≤ 2.0. When the winding is star-connected in series, a = 1; when the winding is delta-connected in series, a = 1.732.

[0007] In one embodiment, the range of the number of turns N of the winding is: 50 < N < 150.

[0008] In one embodiment, the range of the width t of the magnetic bridge is: 0.35 mm < t < 0.6 mm.

[0009] In one embodiment, the range of the width L of the permanent magnet is: 1 mm < L < 2 mm.

[0010] In one embodiment, the width L of the permanent magnet ranges from 1.3 mm < L < 1.5 mm.

[0011] In one embodiment, the range of δ is: 0.45 mm < δ < 0.7 mm.

[0012] In one embodiment, the remanence of the permanent magnet is Br, and 0.5 ≤ t×Br ≤ 1.0.

[0013] In one embodiment, when the temperature of the permanent magnet is 20 °C, the remanence Br of the magnet is 1.3 T to 1.5 T.

[0014] In one embodiment, there are a plurality of stator teeth, the stator core further includes an annular stator yoke, and the plurality of stator teeth are arranged at intervals along the circumferential direction of the inner ring surface of the stator yoke to form stator slots between any two adjacent stator teeth. The winding is wound around the stator teeth and is located in the stator slots. The number of slots of the stator slots is Q, the number of pole pairs of the rotor is P, and 6 ≤ N×Q×P / (100×L) ≤ 10.

[0015] In one embodiment, the range of the number of slots Q of the stator slots is: 15 ≤ Q ≤ 18.

[0016] In one embodiment, the number of pole pairs of the rotor is P, and 5 ≤ P ≤ 6.

[0017] In one embodiment, the number of slots per pole per phase of the motor is q, the number of phases of the motor is m, q = Q / (2×m×P), and q < 1.

[0018] The present utility model also provides a compressor, including the above-mentioned motor.

[0019] The present utility model also provides a refrigeration device, including the above-mentioned compressor.

[0020] The technical solution of the present utility model improves the anti-demagnetization ability of the motor by controlling the mutual cooperation of the magnetic bridge width t, the air gap δ, the width L of the permanent magnet, the number of turns N of the winding, and the winding constant a when the winding is connected in different ways. This solution limits (N×t) / (21.5×a×δ×L 2 ) to 1.9 ≤ (N×t) / (21.5×a×δ×L 2 ) ≤ 2.0, so that the demagnetization current becomes larger, and thus the anti-demagnetization ability of the motor is enhanced. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0022] Figure 1 Structural schematic diagram of an embodiment of the motor provided by the present invention;

[0023] Figure 2 For Figure 1 Partial enlarged view at position A in

[0024] Figure 3 Structural schematic diagram when the windings of the motor of the present invention are star-connected in series;

[0025] Figure 4 Structural schematic diagram when the windings of the motor of the present invention are delta-connected in series;

[0026] Figure 5 Experimental data table of the current value and (N×t) / (21.5×a×δ×L 2 ) of the motor provided by the present invention at a demagnetization rate of 3%;

[0027] Figure 6 Schematic diagram of the change of the current value of the motor provided by the present invention with (N×t) / (21.5×a×δ×L 2 ) at a demagnetization rate of 3%;

[0028] Figure 7 Experimental data table of the maximum operating speed, motor efficiency and N×Q×P / (100×L) of the motor provided by the present invention.

[0029] Figure 8 Schematic diagram of the change of the maximum operating speed and motor efficiency of the motor provided by the present invention with N×Q×P / (100×L).

[0030] Figure 9 Experimental data table of the force density amplitude and t×Br of the motor provided by the present invention.

[0031] Figure 10 Schematic diagram of the change of the force density amplitude of the motor with t×Br.

[0032] Explanation of the reference numerals in the drawings:

[0033] 1. Motor; 100. Stator core; 110. Stator teeth; 120. Stator yoke; 130. Stator slots; 200. Rotor; 210. Rotor core; 211. Magnet slots; 212. Magnetic bridges; 220. Permanent magnets.

[0034] The realization, functional features, and advantages of the present utility model will be further described in conjunction with embodiments and with reference to the accompanying drawings. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0036] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, then such directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If this specific posture changes, then such directional indications will also change accordingly.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, then such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0038] Generally speaking, when the number of turns of the motor winding increases, the resistance of the motor will decrease, the current will increase, and at the same time, a stronger magnetic field will be generated. However, this does not mean that the more turns, the stronger the demagnetization resistance of the motor. In fact, when the number of turns increases to a certain extent, the magnetic flux distribution of the motor will be more uniform, and the magnetic density (magnetic flux per unit area) will decrease correspondingly, which may cause the motor to be more prone to demagnetization under the action of an external magnetic field. Moreover, the inductance of the motor is a parameter closely related to the number of turns of the winding. When the number of turns increases, the inductance also increases, and the inductive reactance increases. This helps to stabilize the current and voltage of the motor and improve the power factor of the motor. However, too large an inductance will also cause the motor to be subjected to greater electromagnetic shocks during startup or operation, which may increase the risk of demagnetization. Secondly, when the width of the magnetic bridge of the rotor is small, the demagnetization resistance of the permanent magnet may be strong because at this time the magnetic force lines are more likely to directly pass through the silicon steel sheet between the magnetic barriers, reducing magnetic leakage. However, too small a magnetic bridge width may cause the rated electromagnetic torque of the motor to decrease because the path of the magnetic force lines passing through the magnetic bridge is reduced. Then, the air gap of the motor is also a factor affecting the demagnetization resistance of the motor. A smaller air gap length can improve the demagnetization resistance and efficiency of the motor, but may increase the manufacturing cost and difficulty. A larger air gap length can reduce the manufacturing cost and difficulty, but may reduce the performance and efficiency of the motor. Furthermore, the length of the permanent magnet affects the design of the magnetic circuit of the motor. And the rationality of the magnetic circuit design directly affects the performance and demagnetization resistance of the motor. Therefore, in the design of the motor 1, it is necessary to select a suitable magnetic bridge 212 width t, a reasonable air gap δ, a reasonable permanent magnet width L, and a reasonable number of winding turns N to cooperate with each other to improve the demagnetization resistance of the motor 1.

[0039] The present utility model provides a motor 1.

[0040] Please refer to Figure 1 and Figure 2 In an embodiment of the present utility model, the motor 1 includes a stator and a rotor 200. The minimum inner diameter of the stator 100 is D 1 The maximum outer diameter of the rotor 200 is D 2 The stator includes a stator core 100 and a winding. The winding is wound around the stator teeth 110 of the stator core 100. The number of turns of the winding is N, and the constant of the winding is a. The rotor 200 is rotatably disposed inside the stator to form an air gap δ between the stator and the rotor 200. The rotor 200 includes a rotor core 210 and a permanent magnet 220. The rotor core 210 is provided with a magnet slot 211. A magnetic bridge 212 is formed between the magnet slot 211 and the outer peripheral edge of the rotor core 210. The width of the magnetic bridge 212 is t. The permanent magnet 220 is disposed in the magnet slot 211. The length of the permanent magnet 220 is L, and 1.9 ≤ (N × t) / (21.5 × a × δ × L 2) ≤ 2.0, when the windings are star-connected in series, a = 1, refer to Figure 3 , Figure 3 is the schematic structural diagram of the star-connected series of windings in the motor 1 of the present invention; when the windings are delta-connected in series, a = 1.732, refer to Figure 4 , Figure 4 is the schematic structural diagram of the delta-connected series of windings in the motor 1 of the present invention.

[0041] The technical solution of the present invention improves the anti-demagnetization ability of the motor 1 by controlling the mutual cooperation of the width t of the magnetic bridge 212, the air gap δ, the width L of the permanent magnet, the number of turns N of the winding, and the winding constant a in different connection modes of the winding, refer to Figure 5 and Figure 6 , Figure 5 is the calculation data of (N×t) / (21.5×a×δ×L 2 ) and the experimental data table of the current value at a demagnetization rate of 3%. Figure 6 is the schematic diagram of the change of the current value with (N×t) / (21.5×a×δ×L 2 ) at a demagnetization rate of 3%. From Figure 5 and Figure 6 it can be seen that when the ratio of (N×t) / (21.5×a×δ×L 2 ) is less than 2, as the ratio of (N×t) / (21.5×a×δ×L 2 ) increases, the current value also gradually increases, and reaches the maximum value when the ratio of (N×t) / (21.5×a×δ×L 2 ) is equal to 2, while when the ratio of (N×t) / (21.5×a×δ×L 2 ) is greater than 2, the current value shows a downward trend, refer to Figure 5 it can be seen that when the ratio of (N×t) / (21.5×a×δ×L 2 ) is between 1.9 and 2.0, the current value reaches a relatively large value, and the current value is between 32 A and 33 A. Therefore, restricting (N×t) / (21.5×a×δ×L 2 ) to 1.9 ≤ (N×t) / (21.5×a×δ×L 2 ) ≤ 2.0 is beneficial to increasing the demagnetization current, so as to enhance the anti-demagnetization ability of the motor 1.

[0042] It should be noted that when the windings are star-connected in series, the value of a in (N×t) / (21.5×a×δ×L 2 ) is 1; while when the windings are delta-connected in series, (N×t) / (21.5×a×δ×L 2) The value of a is 1.732. The width t of the magnetic bridge 212 refers to the minimum distance between the magnet slot 211 and the outer edge of the rotor 200. The width L of the permanent magnet refers to the distance between two parallel side walls in the width direction of the permanent magnet. The width of the permanent magnet includes the width of the angular fillet. For a special-shaped permanent magnet, such as a pentagonal permanent magnet with a missing corner, it refers to the distance between two parallel side walls.

[0043] Further, a plurality of stator teeth 110 are provided, and the stator core 100 further includes an annular stator yoke 120. The plurality of stator teeth 110 are arranged at intervals along the circumferential direction of the inner ring surface of the stator yoke 120 to form a stator slot 130 between any two adjacent stator teeth 110. The winding is wound around the stator teeth 110 and is located in the stator slot 130. The number of slots of the stator slot 130 is Q, and the number of pole pairs of the rotor 200 is P, and 6 ≤ N×Q×P / (100×L) ≤ 10.

[0044] Refer to Figure 7 and Figure 8 , Figure 7 is an experimental data table of the calculation data of N×Q×P / (100×L) and the maximum operating speed and efficiency of the motor 1. Figure 8 is a schematic diagram of the change of the maximum operating speed and efficiency of the motor 1 with N×Q×P / (100×L). It can be seen from Figure 7 and Figure 8 that as the value of N×Q×P / (100×L) increases, the maximum operating speed of the motor 1 gradually decreases, and as the value of N×Q×P / (100×L) gradually increases, the efficiency of the motor 1 also gradually increases. When 6 ≤ N×Q×P / (100×L) ≤ 10, both the maximum operating speed and efficiency of the motor 1 are at relatively optimal values, and when N×Q×P / (100×L) is equal to 8, both the maximum operating speed and efficiency of the motor 1 can reach optimal values.

[0045] Optionally, the number of slots Q of the stator slots 130 ranges from 15 ≤ Q ≤ 18; it can be understood that the number of slots Q of the stator slots 130 within this range can provide relatively balanced performance. It is neither too few to affect the efficiency and torque of the motor 1 nor too many to cause a significant increase in manufacturing costs. Moreover, restricting the number of slots Q of the stator slots 130 between 15 and 18 helps to provide a more uniform magnetic field distribution, thereby reducing the non-uniformity of the magnetic field and improving the efficiency and performance of the motor. Secondly, restricting the number of slots Q of the stator slots 130 between 15 and 18 can make the magnetic field of the motor 1 more uniform, reduce the magnetic field fluctuations, and thus reduce the noise of the motor 1. At the same time, it also helps to reduce the vibration of the motor 1. Compared with the motor 1 with a higher number of stator slots 130, the motor 1 with 15 to 18 slots may be more advantageous in terms of manufacturing costs because they do not require excessive winding coils and insulating materials, reducing the manufacturing difficulty and cost. Restricting the number of slots Q of the stator slots 130 between 15 and 18 can improve the efficiency and torque density of the motor. Although increasing the number of slots Q of the stator slots 130 can further improve these performance parameters, relatively high efficiency and torque can already be achieved within the range of 15 to 18.

[0046] Optionally, the number of pole pairs of the rotor 200 is P, 5 ≤ P ≤ 6; the motor 1 with the number of pole pairs P between 5 and 6 can achieve a better balance between torque and speed. Compared with the motor 1 with fewer pole pairs (such as a 2-pole motor), the motor 1 with the number of pole pairs P between 5 and 6 has higher torque and lower speed, and is suitable for application scenarios that require high torque and lower speed. Compared with motors with more pole pairs (such as 8 poles or more), the motor 1 with the number of pole pairs P between 5 and 6 can avoid problems such as the increase in the motor body size and the increase in rotor inertia caused by too many pole numbers, thus maintaining high efficiency.

[0047] Optionally, the number of slots per pole per phase of the motor 1 is q, the number of phases of the motor 1 is m, q = Q / (2×m×P), and q < 1. It can be understood that the number of slots per pole per phase q is equal to the ratio of the number of slots of the stator slots 130 to twice the product of the number of pole pairs of the rotor 200 and the number of phases of the motor 1, and the number of slots per pole per phase q is made less than 1, so that a fractional-slot motor can be formed as a whole. Under the action of the fractional-slot motor, the cogging torque induced by the permanent magnet magnetic field of the rotor 200 can be effectively weakened. Moreover, the fractional-slot motor can effectively increase the equivalent number of slots per pole per phase. This means that under the same number of slots, the fractional-slot motor can obtain better distribution performance, making the motor waveform closer to a sine wave. This helps to improve the efficiency and performance of the motor 1. Secondly, the fractional-slot motor can effectively weaken the per-pole magnetic flux pulsation caused by the change of the air-gap permeance, thereby reducing the pulsation amplitude. This helps to improve the electromotive force waveform and reduce the pulsation loss, and improve the operating efficiency and stability of the motor 1. Since the fractional-slot motor uses fewer slots to obtain the same distribution performance as an integer-slot winding with a large number of slots, its number of slots is relatively small, and it has good processability. This helps to reduce the manufacturing cost of the motor 1 and improve the production efficiency. Furthermore, the torque characteristics of the fractional-slot motor are usually good, and the torque ripple is small. This is because the fractional-slot motor can optimize the magnetic field distribution, reduce the harmonic components, and thus reduce the torque ripple. This makes the fractional-slot motor have an advantage in occasions where high-precision control and stable operation are required.

[0048] Optionally, the remanence of the permanent magnet 220 is Br, 0.5 ≤ t×Br ≤ 1.0. Refer to Figure 9 and Figure 10 , Figure 9 which is an experimental data table of the numerical value of t×Br and the amplitude value of the force density of the motor. Figure 10 is a schematic diagram of the change of the amplitude value of the force density of the motor with t×Br. From Figure 9 and Figure 10 it can be seen that when t×Br is less than 0.75, as the numerical value of t×Br increases, the amplitude value of the force density of the motor 1 gradually decreases, and when t×Br is greater than 0.75, as the numerical value of t×Br increases, the amplitude value of the force density of the motor 1 gradually increases, and when 0.5 ≤ t×Br ≤ 1.0, the numerical value of the amplitude value of the force density of the motor 1 is relatively small.

[0049] For the remanence Br of the permanent magnet 220, the greater the remanence, the smaller the current required for the motor 1 to reach the required torque during operation. Therefore, the torque generated by the motor 1 under the same current is greater, thus improving the efficiency of the motor 1; in addition, the magnitude of the remanence also affects the vibration and noise of the motor 1. An appropriate remanence can reduce the vibration and noise of the motor 1 and improve the operating smoothness of the motor 1. From Figure 9 and Figure 10It can be known that limiting 0.5≤t×Br≤1.0 can make the numerical value of the force density amplitude of the motor relatively small, so as to ensure that the motor 1 achieves the best performance in the design and manufacturing process.

[0050] In an embodiment, after reasonably setting the material of the permanent magnet 220, the width t of the appropriate magnetic bridge 212, the reasonable air gap δ, the reasonable width L of the permanent magnet, the reasonable number of winding turns N, and the winding constant a in different connection modes of the winding through the technical solution of the present invention, when the temperature of the permanent magnet 220 is 20 °C, the remanence of the magnet is 1.3T to 1.5T. Remanence means the magnetic field intensity maintained by the permanent magnet 220 itself after removing the external magnetic field. The remanence of 1.3T to 1.5T indicates that the permanent magnet 220 has a strong magnetism at room temperature and can generate a significant magnetic field. Thus, it can be clearly shown that for the motor 1 after reasonably coordinating the material of the permanent magnet 220, the width t of the appropriate magnetic bridge 212, the reasonable air gap δ, and the reasonable width L of the permanent magnet, the magnetic strength of the permanent magnet 220 is higher, thereby improving the magnetic ability of the permanent magnet 220 and further improving the performance and energy efficiency of the motor 1.

[0051] Refer to Figure 1 and Figure 2 Furthermore, the rotor core 210 includes a plurality of rotor 200 laminations stacked in the axial direction, and the stator core 100 includes a plurality of stator laminations stacked in the axial direction. Thus, when processing the stator core 100 and the rotor core 210, only a plurality of stator laminations or rotor 200 laminations need to be processed, and then the plurality of stator laminations and rotor 200 lamination parts are assembled into the stator core 100 and the rotor core 210. Compared with processing a complete stator core 100 and rotor core 210, the difficulty of processing the stator laminations and rotor 200 lamination parts is reduced, which is convenient for realizing the automated production of the stator core 100 and the rotor core 210 through an automated production line, thereby reducing the production cost.

[0052] In an embodiment, the rotor core 210 and the stator core 100 can be of different materials or shapes, so as to meet the requirements of different processing technologies for the stator and the rotor 200, which is beneficial to selecting appropriate laminations according to the performance requirements of the motor 1 to form the rotor core 210 and the stator core 100, thereby ensuring the good performance of the electrode and at the same time improving the wide application range of the motor 1. In another embodiment, the stator laminations stacked into the stator core 100 and the rotor 200 laminations stacked into the rotor core 210 are the same, which is beneficial to the batch production of the laminations and reduces the manufacturing cost.

[0053] Furthermore, the punching sheet is a punching sheet made of soft magnetic material. The soft magnetic material can achieve a large magnetization intensity with a relatively small external magnetic field. The soft magnetic material has low coercivity and high magnetic permeability, which is beneficial to reducing the losses of the stator core 100 and / or the rotor core 210, that is, reducing the iron loss of the motor 1, and thus is beneficial to improving the performance of the motor 1. Specifically, the punching sheet is a silicon steel sheet. It can be understood that the punching sheet can also be made of other materials.

[0054] To ensure that the rotor core 210 will not have problems such as loose sheets or interlayer misalignment, in this embodiment, the rotor core 210 is provided with a plurality of rivet holes. Through the cooperation of the rivets and the rivet holes, the fixing strength between the punching sheets of the rotor 200 can be satisfied, thereby avoiding the problem of interlayer misalignment of the punching sheets of the rotor 200 during subsequent processing.

[0055] It should be noted that in order to reduce or even avoid the problem of interlayer eddy current conduction caused by this overlapping riveting structure, the punching sheets of the rotor 200 can be adhesively bonded with glue instead of the overlapping riveting method, which can prevent the insulation surface layer of the punching sheets of the rotor 200 at the rivet holes from being damaged, thereby avoiding the problem of interlayer eddy current conduction. However, due to the high price of glue and the low production efficiency of the production line, it has not been applied to the motor 1 of the air-conditioning compressor.

[0056] Among them, the permanent magnet 220 is made of rare earth materials. The permanent magnet 220 made of rare earth materials has the following advantages: 1. High-temperature stability: When the temperature of the rare earth permanent magnet material rises, the coefficient of the residual magnetic induction intensity changing with temperature can be made very small. At the same time, for some rare earth permanent magnet materials such as neodymium iron boron, the Curie temperature can reach 850 °C under appropriate processes. The Curie temperature (Tc) refers to the temperature at which the spontaneous magnetization intensity in the magnetic material drops to zero, which ensures that they can still work normally at high temperatures. 2. Excellent magnetic properties: The rare earth permanent magnet material has a high magnetic energy product, residual magnetism and high coercivity. For example, the magnetic energy product of the neodymium iron boron-based permanent magnet 220 is between 27 and 50 MGOe, which is currently the permanent magnet material with the highest magnetism. 3. Demagnetization curve characteristics: Compared with traditional permanent magnet materials, the demagnetization curve of rare earth materials is basically a straight line, and the demagnetization curve and the recovery curve basically coincide, which helps to achieve more stable performance in applications.

[0057] In this embodiment, the rotor core 210 is further provided with a shaft hole and a through-flow hole. The shaft hole is used to install a transmission shaft so as to drive a driven object to rotate. After the motor 1 is used for a long time, its temperature is likely to rise, which may easily cause the permanent magnet 220 to demagnetize, resulting in the loss or reduction of the magnetism of the permanent magnet 220. Therefore, in this embodiment, by providing a through-flow hole in the rotor core 210, a refrigerant flows through the through-flow hole, and the temperature of the rotor core 210 can be reduced by the refrigerant, so as to maintain the permanent magnet 220 within the optimal range, thereby improving the performance of the motor 1.

[0058] In this embodiment, the number of turns N of the winding ranges from 50 < N < 150. It can be understood that limiting the number of turns of the winding between 50 and 150 is beneficial to the shape matching between the winding and the stator slot 130, improving the slot filling factor of the stator slot 130. Moreover, limiting the number of turns of the winding between 50 and 150 can avoid excessive number of turns of the winding, resulting in too large resistance of the winding, and can reduce the material cost of the motor 1 while improving the efficiency of the motor 1.

[0059] Furthermore, the width t of the magnetic bridge 212 ranges from 0.35 mm < t < 0.6 mm. First of all, limiting the width t of the magnetic bridge 212 between 0.35 mm and 0.6 mm is beneficial to ensuring the rigidity of the rotor 200, so that the rigidity of the rotor 200 is sufficient to support the high-speed rotation of the rotor 200. Moreover, limiting the width t of the magnetic bridge 212 between 0.35 mm and 0.6 mm can ensure the rigidity of the rotor 200 while reducing the material consumption, thereby reducing the cost of the rotor 200. Furthermore, limiting the width t of the magnetic bridge 212 between 0.35 mm and 0.6 mm can adjust the magnetic field distribution, reduce magnetic leakage, and thus improve the magnetic field effect. If the width t of the magnetic bridge 212 is less than or equal to 0.35 mm, the too small width t of the magnetic bridge 212 is likely to cause the structural strength to be difficult to maintain at a relatively high rotational speed of the rotor 200; if the width t of the magnetic bridge 212 is greater than or equal to 0.6 mm, it will result in too large a width of the magnetic bridge 212, which will not only increase the material cost but also increase the magnetic leakage and reduce the efficiency of the motor 1.

[0060] In one embodiment, the width L of the permanent magnet 220 ranges from 1 mm < L < 2 mm. It can be understood that if the width L of the permanent magnet 220 is too short, the magnetic field strength of the motor 1 will be insufficient and the efficiency of the motor 1 will be low; when the length is too long, not only will the weight of the motor 1 increase and the efficiency of the motor 1 decrease, but also the cost of the motor 1 will increase. This solution limits the width L of the permanent magnet 220 between 1 mm and 2 mm, which is beneficial to reducing the production cost while ensuring the efficiency of the motor 1. If the width L of the permanent magnet 220 < 1 mm, it will lead to insufficient magnetic field strength of the motor 1 and reduce the efficiency of the motor 1. If the width L of the permanent magnet 220 is greater than 2 mm, it will increase the weight of the motor 1, reduce the efficiency of the motor 1, and increase the cost of the motor 1.

[0061] Further, the width L of the permanent magnet 220 ranges from 1.3 mm < L < 1.5 mm, which can make the utilization rate of the permanent magnet 220 reach a better level and is beneficial to making the motor efficiency reach the best.

[0062] Wherein, the minimum inner diameter of the stator 100 is D 1 , the maximum outer diameter of the rotor 200 is D 2 , the air gap of the motor 1 is, and δ = (D 1 - D 2 ) / 2. The range of the air gap δ is: 0.45 mm < δ < 0.7 mm; it can be understood that if the air gap δ decreases or increases too much, the efficiency of the motor 1 will decrease. Because too small an air gap δ will increase the frictional loss inside the motor 1, and too large an air gap δ will not only cause the magnetic field strength to weaken and reduce the efficiency of the motor 1, but also make the rotation of the motor 1 unstable, cause collisions inside the motor 1, and increase the vibration. This solution limits the air gap δ between 0.45 mm and 0.7 mm, which is beneficial to ensuring the stable operation inside the rotor 200 while ensuring the efficiency of the motor 1. If the air gap δ is less than 0.45 mm, it will not only reduce the efficiency of the motor 1, but also increase the frictional loss inside the motor 1. When the air gap δ is greater than 0.7 mm, it is easy to make the rotation of the rotor 200 unstable, cause collisions inside the motor 1, and increase the vibration.

[0063] In one embodiment, the magnetic field direction of the permanent magnet 220 is parallel to the radial direction of the rotor core 210. That is, the rotor topology is a radial structure. This is because the radial structure has the following advantages: 1. Small leakage magnetic coefficient: Since the radial structure arranges the permanent magnets 220 along the radius direction of the rotor 200, this structure helps to reduce the leakage of magnetic flux outside the rotor 200, thereby reducing the leakage magnetic coefficient. A smaller leakage magnetic coefficient means that more magnetic flux can be effectively utilized to generate electromagnetic torque, improving the efficiency of the motor 1. 2. No isolation measures are required on the rotor 200: The design of the radial structure makes the permanent magnets 220 arranged closely on the rotor 200, reducing the possibility of magnetic flux leakage. Therefore, no additional isolation measures are needed to prevent the influence of magnetic flux on other parts of the motor 1. This simplifies the structure of the motor 1 and reduces the manufacturing cost. 3. The pole arc coefficient is easy to control: In the radial structure, by adjusting the shape, size, and number of the permanent magnets 220, the pole arc coefficient can be relatively easily controlled, thereby achieving precise control of the performance of the motor 1. This helps to meet different application requirements and optimize the performance of the motor 1. 4. The rotor 200 punching sheet has high mechanical strength: The radial structure makes the permanent magnets 220 evenly distributed on the rotor 200 core, which helps to improve the mechanical strength of the rotor 200 punching sheet. Higher mechanical strength means that the rotor 200 can withstand greater torque and higher rotational speed, improving the reliability and durability of the motor 1. 5. The rotor 200 is not easily deformed after installing the permanent magnet 220: Since the radial structure makes the permanent magnets 220 tightly embedded in the rotor 200 core, this structure helps to reduce the deformation of the rotor 200 during high-speed rotation. The stable shape of the rotor 200 helps to maintain the stable performance of the motor 1 and reduce vibration and noise.

[0064] The present utility model also provides a compressor, which includes a motor. The specific structure of the motor refers to the above embodiments. Since this compressor adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0065] The present utility model also provides a refrigeration device, which includes a compressor. The specific structure of the compressor refers to the above embodiments. Since this refrigeration device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0066] The above are only exemplary embodiments of the present utility model, and do not limit the patent scope of the present utility model. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present utility model.

Claims

1. A motor, characterized in that: include: A stator, the stator comprising a stator core and a winding, the minimum inner diameter of the stator is D1, the winding is wound on the stator teeth of the stator core, the number of turns of the winding is N, and the constant of the winding is a; and A rotor, wherein the rotor is rotatably disposed in the stator to form an air gap δ between the stator and the rotor, wherein the maximum outer diameter of the rotor is D2, wherein δ=(D1-D2) / 2, wherein the rotor comprises a rotor core and a permanent magnet, wherein the rotor core is provided with a magnet slot, wherein a magnetic bridge is formed between the magnet slot and the outer periphery of the rotor core, wherein the width of the magnetic bridge is t, wherein the permanent magnet is disposed in the magnet slot, wherein the length of the permanent magnet is L, wherein 1.9≤(N×t) / (21.5×a×δ×L 2 )≤2.0, when the windings are star-connected in series, a=1; when the windings are delta-connected in series, a=1.

732.

2. The motor according to claim 1, characterized in that The range of the number of turns N of the winding is: 50 <N<150。 3. The motor according to claim 1, characterized in that The width t of the magnetic bridge is in the range of: 0.35 mm <t<0.6mm。 4. The motor according to claim 1, characterized in that The width L of the permanent magnet is in the range of: 1 mm <L<2mm。 5. The motor according to claim 4, characterized in that The width L of the permanent magnet is in the range of: 1.3 mm <L<1.5mm。 6. The motor according to claim 1, characterized in that The range of δ is: 0.45mm<δ<0.7mm.

7. The motor according to claim 1, characterized in that The remanence of the permanent magnet is Br, 0.5≤t×Br≤1.

0.

8. The motor according to claim 7, characterized in that When the temperature of the permanent magnet is 20° C., the remanence Br of the magnet is 1.3T to 1.5T.

9. The motor according to any one of claims 1 to 8, characterized in that: There are multiple stator teeth, and the stator core also includes an annular stator yoke. The multiple stator teeth are arranged at intervals along the circumferential direction of the inner ring surface of the stator yoke to form a stator slot between any two adjacent stator teeth. The winding is wound around the stator teeth and located in the stator slot. The number of stator slots is Q, the number of pole pairs of the rotor is P, and 6≤N×Q×P / (100×L)≤10.

10. The motor according to claim 9, characterized in that The range of the number Q of the stator slots is: 15≤Q≤18.

11. The motor according to claim 9, characterized in that The number of pole pairs of the rotor is P, 5≤P≤6.

12. The motor according to claim 9, characterized in that The number of slots per pole per phase of the motor is defined as q, the number of phases of the motor is defined as m, q=Q / (2×m×P), q<1.

13. A compressor, characterized in that: Comprising the electric machine as claimed in any one of claims 1 to 12.

14. A refrigeration device, characterized in that: Comprising a compressor as claimed in claim 13.

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