A motor and a compressor

Abstract

The utility model belongs to motor field, concretely relates to a kind of motor and a kind of compressor, motor satisfies: 5 / Br≤(Di / Do)×a×Q×S×Spm / (P×h×Wt×Lag×L)≤100 / Br;Wherein, Di is stator lamination inner diameter, Do is stator lamination outer diameter, a is slot fill factor, Q is stator slot number, S is single stator slot area, Spm is single permanent magnet's cross-sectional area, P is pole pair number, h is yoke thickness, Wt is tooth portion shortest width, Lag is minimum air gap width, L is stator axial height, Br is permanent magnet remanence.The utility model solves the prior art cannot reflect the collaborative influence of stator, rotor and permanent magnet on structural loss.The scheme is adjusted the structure cooperation of stator, rotor and permanent magnet, makes coil loss and silicon steel sheet loss in motor operation reach suitable proportion, to obtain higher motor efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of electric motors, specifically relating to an electric motor and a compressor. Background Technology

[0002] As the core power unit of devices and systems such as refrigeration compressors and industrial drive equipment, the energy efficiency level of permanent magnet synchronous motors can directly affect global energy consumption and carbon emission reduction. According to data from the International Energy Agency (IEA), motor systems account for more than 70% of industrial electricity consumption; and as the main energy consumer in the refrigeration chain, a 1% increase in the motor efficiency of compressors can reduce global annual electricity consumption by approximately 12 billion kilowatt-hours.

[0003] Rare-earth permanent magnet materials (such as neodymium iron boron) are key to improving the power density of motors due to their high remanence and coercivity. However, current permanent magnet synchronous motor designs generally face the bottleneck of balancing efficiency improvement and material conservation. Traditional optimization methods mostly focus on controlling single losses: increasing the amount of permanent magnets (such as increasing the density of permanent magnets) to reduce copper losses, but this leads to a surge in eddy current losses in silicon steel sheets; using distributed windings to reduce iron losses, but this increases the AC resistance of the coils.

[0004] In the prior art, such as the motor assembly, compressor, and refrigeration equipment disclosed in CN222072836U, the motor assembly includes a rotor and a stator core. The stator core is wound around the rotor and includes a yoke and multiple stator teeth. The multiple stator teeth are connected to the yoke and located on the side of the yoke facing the rotor. The multiple stator teeth are arranged at intervals along the circumference of the stator core. Each stator tooth includes a tooth portion and a tooth tip. One end of the tooth portion is connected to the yoke portion, and the tooth tip is located at the other end of the tooth portion. The yoke portion includes a connecting portion located between two adjacent tooth portions. Along the radial direction of the stator core, the connecting portion has a first wall surface and a second wall surface that are opposite to each other. The minimum distance between the first wall surface and the second wall surface is L1. Along the circumference, the tooth portion has a third wall surface and a fourth wall surface that are opposite to each other. The minimum distance between the third wall surface and the fourth wall surface is L2, satisfying: 0.5≤L1 / L2≤1. This scheme limits the width of the yoke to a certain range by reasonably setting the ratio between the radial width of the yoke and the circumferential width of the teeth, ensuring that the area of ​​the winding slot is large enough and reducing the loss of the motor assembly. For example, CN114079333A discloses a motor, compressor, and electrical equipment, wherein the motor includes: a stator assembly, which includes a stator and windings wound on the stator; the stator includes: multiple stacked stator laminations, each stator lamination including multiple modular laminations that can be assembled and connected; each modular lamination includes: teeth and a yoke, the yoke being located within the teeth, and a slot being provided on the side of the yoke opposite to the teeth; a rotor, disposed within the stator, having P pole pairs and N maximum operating speed; and a frequency converter assembly electrically connected to the stator assembly and / or the rotor, the carrier frequency of the frequency converter assembly being fc, satisfying 9≤fc / (P×N)≤15.6, where fc is in Hz. This solution uses a lower carrier frequency for motors with a low number of pole pairs to reduce inverter losses and improve compressor energy efficiency while meeting inverter requirements.

[0005] However, current research mainly focuses on a small portion of the structural parameters in the motor, making it difficult to reflect the synergistic effect of the stator, rotor, and permanent magnet on coil losses and silicon steel sheet losses in the motor structure. Utility Model Content

[0006] The purpose of this invention is to provide a motor and a compressor to solve at least one of the aforementioned problems. This addresses the shortcomings of existing technologies that only consider the influence of the stator yoke and teeth on structural losses, failing to reflect the synergistic influence of the stator, rotor, and permanent magnets on structural losses. This solution achieves higher motor efficiency by adjusting the structural fit between the stator, rotor, and permanent magnets, thus ensuring a suitable ratio between coil losses and silicon steel sheet losses (total stator and rotor materials).

[0007] The objective of this utility model is achieved through the following technical solution:

[0008] The first aspect of this utility model discloses an electric motor, including stator laminations, rotor laminations, permanent magnets, and stator windings;

[0009] The stator laminations are stacked to form a stator, the stator is provided with stator slots spaced apart circumferentially, teeth are formed between the stator slots, and a yoke is formed between the outer wall of the stator and the stator slots;

[0010] The rotor laminations are stacked to form a rotor, and the rotor is provided with pairs of magnet slots spaced apart along the circumferential direction. Each pair of magnet slots is composed of a pair of magnet slots arranged in a V-shape.

[0011] The stator winding is disposed in the stator slot of the stator, and the stator winding is wound on the tooth portion;

[0012] The permanent magnet is disposed in the magnetic slot of the rotor;

[0013] The motor structure described satisfies:

[0014] 5 / Br≤(Di / Do)×a×Q×S×Spm / (P×h×Wt×Lag×L)≤100 / Br;

[0015] in,

[0016] Di is the inner diameter of the stator lamination, Do is the outer diameter of the stator lamination, a is the slot fill factor, Q is the number of stator slots, S is the area of ​​a single stator slot, Spm is the cross-sectional area of ​​a single permanent magnet perpendicular to the motor axis, P is the number of pole pairs, h is the yoke thickness, Wt is the shortest tooth width, Lag is the minimum air gap width, and L is the stator axial height.

[0017] Br represents the remanence of the permanent magnet.

[0018] In the above formula, Di, Do, a, Q, S, Spm, P, h, Wt, Lag, and L are all structural parameters related to the motor structure; Br is a characteristic parameter of the permanent magnet material, which is a constant after the permanent magnet material is determined.

[0019] Preferably, in the motor structure,

[0020] The number of stator slots Q and the number of pole pairs P satisfy the following condition: Q:P = 3:2, such as a 12-pole 18-slot motor, a 10-pole 15-slot motor, an 8-pole 12-slot motor, and a 6-pole 9-slot motor.

[0021] Preferably, in the motor structure,

[0022] The outer diameter Do of the stator lamination must satisfy: 80mm≤Do≤120mm.

[0023] Preferably, in the motor structure,

[0024] The inner diameter Di of the stator laminations must satisfy: 40mm≤Di≤90mm;

[0025] The minimum air gap width Lag is the difference between the inner diameter Di of the stator lamination and the maximum outer diameter Dr of the rotor lamination. The minimum air gap width Lag satisfies: 0.3mm≤Lag≤1mm.

[0026] Preferably, in the motor structure,

[0027] The thickness h of the yoke satisfies: 3mm≤h≤12mm.

[0028] Preferably, in the motor structure,

[0029] The minimum width Wt of the tooth must satisfy: 3mm≤Wt≤9mm.

[0030] Preferably, in the motor structure,

[0031] The stator axial height L satisfies: 15mm≤L≤60mm.

[0032] Preferably, in the motor structure,

[0033] The area S of the stator slot satisfies: 50mm 2 ≤S≤300mm 2 .

[0034] The stator dimensions and stator slot area of ​​a motor affect the ratio between the losses generated by the coils and the losses generated by the stator. Therefore, by optimizing the outer diameter, inner diameter, yoke thickness, initial minimum width, and axial height of the stator laminations, it is beneficial to balance the efficiency and cost of the motor.

[0035] Preferably, in the motor structure,

[0036] The cross-sectional area Spm of a single permanent magnet perpendicular to the motor axis satisfies: 130 mm. 2 ≤S≤280mm 2 .

[0037] Preferably, in the motor structure,

[0038] The remanence Br of the permanent magnet ranges from 1.25T to 1.6T.

[0039] The cross-sectional area and remanence of the permanent magnet indicate the amount of permanent magnet used and the magnetic field strength generated by the permanent magnet at the stator. By optimizing these parameters, the magnetic field strength at the stator of the motor is ensured to be within a suitable range, resulting in higher motor efficiency.

[0040] The second aspect of this utility model discloses a compressor.

[0041] The compressor includes any of the motors described above.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] If (Di / Do)×a×Q×S×Spm / (P×h×Wt×Lag×L) is greater than 100 / Br, although the coil loss of the motor can be greatly reduced, the additional loss generated by the silicon steel sheet will be much greater than the reduction in coil loss, resulting in a decrease in motor efficiency. If (Di / Do)×a×Q×S×Spm / (P×h×Wt×Lag×L) is less than 5 / Br, the coil loss is too large, which will also lead to a decrease in motor efficiency, and may even cause the motor coil to overheat, damage the coil insulation, and cause safety hazards.

[0044] This scheme further examines multiple structural parameters of the stator laminations, including inner and outer diameters, slot fill factor, number of stator slots, slot area, cross-sectional area of ​​permanent magnets, number of pole pairs, yoke thickness, minimum tooth width, minimum air gap width, and stator axial height. It reflects the synergistic influence of the stator, rotor, and permanent magnets on coil losses and silicon steel sheet losses, and provides guidance for optimizing the motor structure and achieving higher motor efficiency. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the stator laminations in an electric motor.

[0046] Figure 2 This is a schematic diagram of the rotor laminations in an electric motor.

[0047] In the figure: 1-stator lamination; 2-rotor lamination; 11-stator slot; 12-tooth section; 13-yoke section; 21-magnet slot. Detailed Implementation

[0048] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0049] Unless otherwise specified, the materials used in the following description are conventional commercial products, and any matters not covered herein may be addressed using existing technologies.

[0050] Example

[0051] A motor structure that reduces the proportion of coil losses, such as Figure 1 , 2 As shown, it includes stator lamination 1, rotor lamination 2, permanent magnets and stator windings;

[0052] The stator laminations 1 are stacked to form a stator. The stator is provided with stator slots 11 spaced apart along the circumference. Teeth 12 are formed between the stator slots 11. A yoke 13 is formed between the outer wall of the stator and the stator slots 11.

[0053] The rotor laminations 2 are stacked to form a rotor, and the rotor is provided with pairs of magnet slots spaced apart along the circumference. Each pair of magnet slots is composed of a pair of magnet slots 21 arranged in a V-shape.

[0054] The stator winding is disposed in the stator slot 11 of the stator, and the stator winding is wound on the tooth portion 12;

[0055] The permanent magnet is disposed in the magnetic slot 21 of the rotor;

[0056] The characteristic is that the motor structure satisfies:

[0057] 5 / Br≤(Di / Do)×a×Q×S×Spm / (P×h×Wt×Lag×L)≤100 / Br;

[0058] in,

[0059] Di is the inner diameter of the stator lamination, Do is the outer diameter of the stator lamination, a is the slot fill factor (the ratio of the cross-sectional area of ​​the conductor portion in the coil to the area S of the stator slot), Q is the number of stator slots, S is the area of ​​a single stator slot, Spm is the cross-sectional area of ​​a single permanent magnet perpendicular to the motor axis (the cross-sectional area of ​​the permanent magnet cut off by a plane perpendicular to the motor axis), P is the number of pole pairs, h is the yoke thickness (the width of the yoke extending radially along the motor), Wt is the shortest tooth width, Lag is the minimum air gap width (the difference between the inner diameter Di of the stator lamination and the maximum outer diameter Dr of the rotor lamination), and L is the stator axial height (the axial stack height of the stator laminations).

[0060] Br represents the remanence of the permanent magnet, which is a constant once the material of the permanent magnet is determined.

[0061] More specifically, in this embodiment:

[0062] The parameters of the motor satisfy the following: the number of stator slots Q and the number of rotor pole pairs P, with the relationship Q / P = 3:2; that is, 12-pole 18-slot motor, 10-pole 15-slot motor, 8-pole 12-slot motor and 6-pole 9-slot motor, etc.

[0063] The dimensions of the motor structure meet the following requirements:

[0064] The outer diameter Do of the stator lamination is in the range of 80mm≤Do≤120mm;

[0065] The range of the inner diameter Di of the stator lamination is 40mm≤Di≤90mm;

[0066] The thickness h of the stator yoke is in the range of 3mm ≤ h ≤ 12mm

[0067] The minimum width Wt of the stator teeth is in the range of 3mm ≤ Wt ≤ 9mm;

[0068] The axial stacking height L of the stator is in the range of 15mm≤L≤60mm;

[0069] The area S of the stator slot satisfies: 50mm 2 ≤S≤300mm 2 ;

[0070] The range of the air gap size Lag is 0.3mm≤Lag≤1mm.

[0071] By limiting the stator size and stator slot area of ​​the motor, the proportional relationship between the losses generated by the coil and the losses generated by the stator is limited, thereby achieving a balance between the high efficiency and cost of the motor.

[0072] The remanence Br of the permanent magnet is in the range of 1.25T≤Br≤1.6T;

[0073] The cross-sectional area Spm of the permanent magnet in the axial direction ranges from 130 mm. 2 ≤S≤280mm 2 .

[0074] Specifically, based on the given range, the grades of permanent magnets that can be selected are between N40 and N56. This solution directly selects suitable commercially available products without making any improvements to the material itself.

[0075] The two parameters mentioned above limit the amount of permanent magnets used and the magnetic field strength generated by the permanent magnets at the stator, thereby ensuring that the magnetic field strength at the stator of the motor is within a suitable range, making the motor more efficient.

[0076] Test case

[0077] For a 10-pole, 15-slot motor, different values ​​were set for several parameters, including Di, Do, a, Q, S, Spm, P, h, Wt, Lag, L, and Br, as shown in Table 1.

[0078] Table 1. Motor parameters for schemes one through three.

[0079] Option 1 Option 2 Option 3 Do(mm) 110 101.1 101.1 Di(mm) 57 63 63 <![CDATA[S(mm 2 )]]> 218.3 125.6 98.2 h(mm) 4 5.85 6.7 Wt(mm) 4.3 5.6 6.2 Lag(mm) 0.5 0.535 0.8 <![CDATA[Spm(mm 2 )]]> 268.8 182 168 L(mm) 30 30 30 Br 1.52T 1.43T 1.4T a 0.4 0.4 0.4 K 116.9 23.3 8.7

[0080] In Table 1, the evaluation coefficient K = (Di / Do) × a × Q × S × Spm × Br / (P × h × Wt × Lag × L).

[0081] The losses and efficiency of the three motors with different structures were measured at a speed of 1260 rpm and a peak load current of 1.5 A. The test results are shown in Table 2. The test method was as follows: the motor under test was mounted on an experimental bench and connected to a dynamometer and a torque sensor. The motor was controlled to operate under the target conditions (1260 rpm and a peak load current of 1.5 A). The test data included the motor torque, speed, coil temperature, coil resistance, and input power. The coil losses (calculated from the applied load current and measured coil resistance), silicon steel sheet losses (calculated by subtracting the output power from the input power and then subtracting the coil losses), motor output power (calculated by multiplying the motor torque by the speed), and motor efficiency (calculated by dividing the output power by the input power) could be obtained through calculation.

[0082] Table 2 Test results of schemes one to three

[0083]

[0084]

[0085] In Scheme 1, the K value is greater than 100, so the coil loss of the motor is greatly reduced, but the loss of its silicon steel sheet is greatly increased. The results show that the amount of copper wire (coil) used in this motor is 74% higher than that in Scheme 2, but the final motor efficiency is lower than that in Scheme 2, at 86.77%.

[0086] Scheme 2 has a K value of 23.3, which is within the range; the results show that it has the highest efficiency among the three schemes, at 88.66%.

[0087] Option 3 has a K value of less than 10, which leads to excessive coil loss. Even if the loss of the silicon steel sheet is reduced slightly, the final motor efficiency is the lowest, at only 83.73%.

[0088] In summary, by using the inequality proposed in this scheme, the coil loss and silicon steel sheet loss during motor operation can be adjusted to achieve a suitable ratio, thereby obtaining higher motor efficiency.

[0089] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.

Claims

1. An electric motor, comprising stator laminations (1), rotor laminations (2), permanent magnets, and stator windings; The stator laminations (1) are stacked to form a stator. The stator is provided with stator slots (11) spaced apart in the circumferential direction. Teeth (12) are formed between the stator slots (11). A yoke (13) is formed between the outer wall of the stator and the stator slots (11). The rotor laminations (2) are stacked to form a rotor, and the rotor is provided with pairs of magnet slots spaced apart along the circumferential direction. The pairs of magnet slots are composed of a pair of magnet slots (21) arranged in a V-shape. The stator winding is disposed in the stator slot (11) of the stator, and the stator winding is wound on the tooth (12); The permanent magnet is disposed in the magnetic slot (21) of the rotor; Its features are, The motor structure described satisfies: 5 / Br≤(Di / Do)×a×Q×S×Spm / (P×h×Wt×Lag×L)≤100 / Br; in, Di is the inner diameter of the stator lamination, Do is the outer diameter of the stator lamination, a is the slot fill factor, Q is the number of stator slots, S is the area of ​​a single stator slot, Spm is the cross-sectional area of ​​a single permanent magnet perpendicular to the motor axis, P is the number of pole pairs, h is the yoke thickness, Wt is the shortest tooth width, Lag is the minimum air gap width, and L is the stator axial height. Br represents the remanence of the permanent magnet.

2. The motor according to claim 1, characterized in that, In the aforementioned motor structure, The number of stator slots Q and the number of pole pairs P satisfy: Q:P = 3:

2.

3. The motor according to claim 1, characterized in that, In the aforementioned motor structure, The outer diameter Do of the stator lamination must satisfy: 80mm≤Do≤120mm.

4. The motor according to claim 1, characterized in that, In the aforementioned motor structure, The inner diameter Di of the stator laminations must satisfy: 40mm≤Di≤90mm; The minimum air gap width Lag is the difference between the inner diameter Di of the stator lamination and the maximum outer diameter Dr of the rotor lamination. The minimum air gap width Lag satisfies: 0.3mm≤Lag≤1mm.

5. The motor according to claim 1, characterized in that, In the aforementioned motor structure, The thickness h of the yoke satisfies: 3mm≤h≤12mm.

6. The motor according to claim 1, characterized in that, In the motor structure described above, the shortest tooth width Wt satisfies: 3mm≤Wt≤9mm.

7. The motor according to claim 1, characterized in that, In the motor structure described above, the stator axial height L satisfies: 15mm≤L≤60mm.

8. The motor according to claim 1, characterized in that, In the described motor structure, the cross-sectional area Spm of a single permanent magnet perpendicular to the motor axis satisfies: 130mm. 2 ≤S≤280mm 2 .

9. The motor according to claim 1, characterized in that, In the motor structure described, the residual magnetism Br of the permanent magnet ranges from 1.25T to 1.6T.

10. A compressor, characterized in that, The compressor includes the motor as described in any one of claims 1-9.

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