motors and compressors

Abstract

This invention provides an electric motor and a compressor. The electric motor includes a stator core formed by axially stacking multiple stator laminations and a rotor core formed by axially stacking multiple rotor laminations. The stator laminations are amorphous alloy laminations, and the rotor laminations are conventional electrical steel laminations. The number of stator laminations is greater than the number of rotor laminations, and the thickness of each stator lamination is less than the thickness of each rotor lamination. This invention enables reasonable limitation of the quantity and thickness of magnetic materials in the stator and rotor cores, effectively reducing motor manufacturing costs while improving motor losses and energy efficiency.

Description

Technical Field

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

[0002] With the further improvement of national energy efficiency requirements, the refrigeration industry has higher requirements for energy saving and efficiency improvement. As the "heart" of refrigeration equipment, the compressor will face the challenge of energy saving and efficiency improvement, and the motor, as the "heart" of the compressor, will be one of the key targets for energy saving and efficiency improvement.

[0003] Permanent magnet synchronous motors (PMSMs) have excellent energy-saving performance and are widely used in industries and home appliances. However, with increasingly stringent energy efficiency requirements, improving the energy efficiency of PMSMs faces severe challenges and even bottlenecks. Therefore, further reducing motor losses has become an important issue in order to further improve the energy efficiency of PMSMs. Utility Model Content

[0004] Therefore, this utility model provides a motor and a compressor that can overcome the technical bottleneck of reducing motor losses in related technologies, which makes it difficult to further improve the energy efficiency of motors.

[0005] To address the aforementioned problems, this utility model provides an electric motor comprising a stator core formed by axially stacking multiple stator laminations and a rotor core formed by axially stacking multiple rotor laminations, wherein the stator laminations are amorphous alloy laminations, the rotor laminations are conventional electrical steel laminations, the number of stator laminations is greater than the number of rotor laminations, and the thickness of each stator lamination is less than the thickness of each rotor lamination.

[0006] In some embodiments, the thickness of the stator laminations is t1, the thickness of the rotor laminations is t2, and 5.2 ≤ t2 / t1 ≤ 41.7.

[0007] In some embodiments, the maximum relative permeability of the stator laminations is greater than the maximum relative permeability of the rotor laminations.

[0008] In some embodiments, the maximum relative permeability of the stator laminations is μ1, and the maximum relative permeability of the rotor laminations is μ2, where μ1 ≥ 24 × 10⁻⁶. 4 And μ1 / μ2≥6.

[0009] In some embodiments, the saturation magnetic flux density of the stator laminations is different from that of the rotor laminations.

[0010] In some embodiments, the saturation magnetic flux density of the stator laminations is Bs1, and the saturation magnetic flux density of the rotor laminations is Bs2, where 0.42 ≤ Bs1 / Bs2 ≤ 1.06.

[0011] In some embodiments, the stator laminations include a yoke ring and a plurality of stator teeth on the inner ring wall of the yoke ring. The stator teeth are evenly spaced along the circumference of the yoke ring, and stator slots are formed between adjacent stator teeth. Each stator tooth includes a tooth bridge and a tooth shoe. The minimum circumferential width of the tooth bridge is Wmin, the maximum circumferential width is Wmax, and the average width of the tooth bridge is W1, where W1 = (Wmin + Wmax) / 2. The outer diameter of the yoke ring is D1. The two opposite circumferential slot walls of the same stator slot extend radially along the stator laminations and intersect the shoe surface of the tooth shoe at a first point and a second point. The circumferential width between the first point and the second point is W2, where 0.094 ≤ (W1 + W2) / D1 ≤ 0.356.

[0012] In some embodiments, the stator core has a split ratio of A, where 0.45 ≤ A ≤ 0.68; and / or the stator core has a number of stator slots of Z, where 6 ≤ Z ≤ 15.

[0013] In some embodiments, the stack height of the stator core is HS, and the stack height of the rotor core is HR, where -2mm≤HR-HS≤5mm.

[0014] This utility model also provides a compressor, including the motor described above.

[0015] The motor and compressor provided by this utility model have the following beneficial effects:

[0016] The stator laminations are made of amorphous alloy, while the rotor laminations are made of conventional electrical steel. This allows for reasonable limitations on the quantity and thickness of magnetic materials in the stator and rotor cores, effectively reducing motor losses and improving motor energy efficiency while lowering motor manufacturing costs. Attached Figure Description

[0017] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram (front view) of the iron core of the motor according to an embodiment of the present invention. Only the stator iron core and the rotor iron core are shown in the figure.

[0019] Figure 2 yes Figure 1 A three-dimensional cross-sectional structural diagram of the motor core in the diagram;

[0020] Figure 3yes Figure 2 A magnified view of a section at point A in the middle;

[0021] Figure 4 This is a three-dimensional structural diagram of the iron core of a motor in the prior art (i.e., the comparative technical solution). Only the stator iron core and the rotor iron core are shown in the figure.

[0022] Figure 5 yes Figure 4 A magnified view of a section at point B in the middle;

[0023] Figure 6 It is a MAP diagram of motor efficiency for motors in the prior art (i.e., motors that do not adopt the technical solution in this application);

[0024] Figure 7 This is a MAP diagram of the motor efficiency of the motor using the technical solution of this utility model;

[0025] Figure 8 This is a comparison diagram of the total iron loss of a motor using the technical solution of this utility model and a motor in the prior art;

[0026] Figure 9 This is a comparison diagram of stator iron loss between a motor using the technical solution of this utility model and a motor in the prior art;

[0027] Figure 10 This is a comparison chart of the motor efficiency of the motor using the technical solution of this utility model and the motor in the prior art;

[0028] Figure 11 for Figure 1 The axial projection of the stator core in the diagram.

[0029] The attached figures are labeled as follows:

[0030] 1. Stator core; 11. Stator laminations; 111. Yoke ring; 112. Stator teeth; 113. Stator slots; 2. Rotor core; 21. Rotor laminations. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0032] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0033] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0034] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0035] See also Figures 1 to 11As shown, according to an embodiment of the present invention, a motor is provided, including a stator core 1 formed by axially stacking multiple stator laminations 11 and a rotor core 2 formed by axially stacking multiple rotor laminations 21. In a specific embodiment, the stator core 1 is fitted onto the radially outer side of the rotor core 2, forming a stator-rotor air gap between them. Stator windings (not shown in the figure, not indexed) are wound on each stator tooth of the stator core 1, and magnets (not shown in the figure, not indexed) are provided on the rotor core 2. The magnets can be assembled on the rotor core 2 by embedding or surface mounting. The stator laminations 11 are amorphous alloy laminations, and the rotor laminations 21 are conventional electrical steel laminations (e.g., conventional silicon steel sheets). The number of stator laminations 11 is greater than the number of rotor laminations 21, and the thickness of each stator lamination 11 is less than the thickness of each rotor lamination 21. The aforementioned amorphous alloy can be, for example, a commercially available Fe-Si-BC series amorphous alloy: Fe 80%–100%, Si 3%–10%, B 0–20%, C 0–5%.

[0036] In this technical solution, the stator lamination 11 is made of amorphous alloy and the rotor lamination 21 is made of conventional electrical steel. This achieves reasonable limitation on the quantity and thickness of magnetic materials for the stator core 1 and the rotor core 2, which can effectively reduce motor losses and improve motor energy efficiency while reducing motor manufacturing costs.

[0037] It is understandable that using amorphous materials (i.e., amorphous alloy materials) for the iron core can effectively reduce iron losses and improve motor efficiency. However, amorphous materials are much more expensive than conventional electrical steel, requiring rational utilization to achieve the highest cost-effectiveness. Considering that the iron loss of stator core 1 accounts for the largest proportion of the total iron loss in the motor, and that the hard and brittle characteristics of amorphous materials are unsuitable for rotor core 2, which has a complex and intricate topology and is subjected to strong centrifugal forces during operation, a strategy of using amorphous materials for the stator and conventional electrical steel for the rotor is adopted. Based on this material allocation strategy, it is necessary to further optimize and limit the thickness t1 of stator lamination 11 and rotor lamination 21 to achieve a comprehensive effect. To maximize the cost-effectiveness of the motor, considering factors such as motor performance, reliability, and cost, this application specifies that the stator core 1 uses amorphous material (stator lamination 11 thickness t1: 0.012mm~0.038mm), and the rotor core 2 uses conventional electrical steel material (rotor lamination 21 thickness t2: 0.20mm~0.50mm). Therefore, t2 / t1 = (0.20mm~0.50mm) / (0.012mm~0.038mm) ≈ (5.2~41.7), meaning the thickness of the stator lamination 11 is t1, and the thickness of the rotor lamination 21 is t2, with 5.2 ≤ t2 / t1 ≤ 41.7. The units for t1 and t2 are both mm.

[0038] In some embodiments, the maximum relative permeability (not absolute permeability, dimensionless) of the stator lamination 11 is greater than the maximum relative permeability of the rotor lamination 21. Specifically, the maximum relative permeability of the stator lamination 11 is μ1, and the maximum relative permeability of the rotor lamination 21 is μ2, where μ1 ≥ 24 × 10⁻⁶. 4 Furthermore, μ1 / μ2 ≥ 6 to ensure a more reasonable selection of magnetic materials for stator core 1 and rotor core 2, thereby ensuring a significant improvement in motor energy efficiency, simplifying the production process, increasing production efficiency, and enhancing motor reliability. It should be noted that when μ1 is below the aforementioned limit, it will lead to excessive stator copper losses, resulting in a less significant efficiency improvement.

[0039] In some embodiments, the saturation magnetic flux density of the stator lamination 11 is different from that of the rotor lamination 21. Specifically, the saturation magnetic flux density of the stator lamination 11 is Bs1 (in tons), and the saturation magnetic flux density of the rotor lamination 21 is Bs2 (in tons). 0.42 ≤ Bs1 / Bs2 ≤ 1.06. If the ratio is less than this range, the motor output torque will be smaller and the energy efficiency will be reduced; if the ratio is greater than this range, the cost of stator materials will be higher.

[0040] When the stator lamination 11 and / or the rotor lamination 21 are prepared by strip punching and shearing, the maximum relative permeability of the stator lamination strip is the aforementioned μ1, and the saturation magnetic flux density is Bs1. Similarly, the maximum relative permeability of the rotor lamination strip is the aforementioned μ2, and the saturation magnetic flux density is Bs2.

[0041] In some embodiments, the stator lamination 11 includes a yoke ring 111 and a plurality of stator teeth 112 located on the inner ring wall of the yoke ring 111. Each stator tooth 112 is evenly spaced along the circumference of the yoke ring 111, and a stator groove 113 is formed between adjacent stator teeth 112. That is, the stator lamination 11 in this invention is an integral structure. Each stator tooth 112 includes a tooth bridge (not labeled in the figure) and a tooth shoe (not labeled in the figure). One end of the tooth bridge is connected to the inner ring wall of the yoke ring 111, and the other end of the tooth bridge is the aforementioned tooth shoe. See details... Figure 11 As shown, the minimum circumferential width of the tooth bridge is Wmin, the maximum circumferential width is Wmax, the average width of the tooth bridge is W1, W1 = (Wmin + Wmax) / 2, the outer diameter of the yoke ring 111 is D1 (that is, the outer diameter of the stator core 1), the two opposite circumferential groove walls of the same stator slot 113 extend radially along the stator lamination 11 and intersect with the shoe surface of the tooth shoe at the first point and the second point, the circumferential width between the first point and the second point is W2, 0.094 ≤ (W1 + W2) / D1 ≤ 0.356, and the unit of the aforementioned widths is mm.

[0042] In this technical solution, by limiting the ratio of the average width W1 of the tooth bridge, the slot width W2 of the stator slot 113, and the outer diameter D1 of the stator core 1, it is possible to achieve a larger slot area to reduce copper loss and improve motor efficiency while ensuring a relatively reasonable stator structure. At the same time, it is easier to insert wires and reduce production difficulty.

[0043] In some embodiments, the ratio of the stator core 1 (specifically, the ratio of the stator inner diameter to the stator outer diameter) is A, where 0.45 ≤ A ≤ 0.68. When A is less than 0.45, it indicates that the rotor diameter is too small, the torque density is low, and the tooth length is not conducive to the production of winding. When A is greater than 0.68, it indicates that the rotor diameter is too large, the teeth are short, and the stator slots are too small. In this application, since the stator core is made of amorphous material and the rotor core is made of electrical steel, an excessively large rotor diameter will result in a small proportion of low-loss amorphous material and a large proportion of high-loss electrical steel material, leading to an insignificant efficiency improvement and difficulties in stator winding production. And / or, the number of stator slots in the stator core 1 is Z, where 6 ≤ Z ≤ 15. If it is less than 6, the number of slots is too small and the number of poles is too large, resulting in prominent high-frequency electromagnetic noise, high permanent magnet eddy current losses, and high rotor costs. If it is greater than 15, the number of slots is too large and the number of poles is too small, resulting in significant mid-to-low frequency electromagnetic noise and vibration, high stator iron losses, and high costs.

[0044] In some implementations, for neodymium iron boron permanent magnet synchronous motors, the stack height of stator core 1 and rotor core 2 are approximately equal. In some cases, to save on electrical steel materials and reduce costs, the stack height may differ by 1 to 2 mm. For ferrite permanent magnet synchronous motors, since ferrite permanent magnet materials have low remanence, ferrite permanent magnet materials are added in the rotor core stack height direction to obtain sufficient air gap magnetic flux density. Therefore, the rotor core stack height will be a few millimeters higher than the stator core stack height, which is limited to 5 mm here. That is, the stack height of stator core 1 is HS, and the stack height of rotor core 2 is HR, where -2mm ≤ HR - HS ≤ 5mm, thereby preventing the difference between the two from being too large and resulting in low material utilization.

[0045] According to an embodiment of the present invention, a compressor is also provided, including the motor described above.

[0046] The technical solution of this application is further described below with reference to a specific embodiment:

[0047] In this specific embodiment: the number of stator slots Z is 12, the stack height of both the stator core and the rotor core is 50mm, the stator lamination thickness t1 is 0.025mm, the rotor lamination thickness t2 is 0.3mm, and t2 / t1 = 12; the maximum relative permeability of the stator lamination strip is μ1 = 25 × 10⁻⁶. 4 The saturation magnetic flux density is Bs1 = 1.56 T. The maximum relative permeability of the rotor lamination strip is μ2 = 4 × 10⁻⁶ T. 4The saturation magnetic flux density is Bs2 = 2.0T, μ1 / μ2 = 6.25, Bs1 / Bs2 = 0.78; W1 = 8.83mm, W2 = 7.15, D1 = 108mm, (W1+W2) / D1≈0.148, and the splitting ratio A≈0.575.

[0048] The comparison of motor efficiency MAP diagrams ( Figure 6 Comparing the stator and rotor cores of the motor (both made of conventional electrical steel), it can be seen that the efficiency of the comparative scheme is only slightly over 95% (within the range of 95% coil height); after adopting the technical solution of this application, the efficiency MAP of the motor in the utility model embodiment is shown in the figure. Figure 7 As can be seen, the efficiency of the utility model embodiment reaches up to 97% (within the range of 97 contour lines), and the efficiency in the region exceeding 95% (within the range of 95 contour lines) is also greatly improved compared to the comparative scheme, resulting in significant efficiency gains.

[0049] Depend on Figure 8 A comparison of the total iron losses of the motors shows that, at the corresponding load points of 1200 / 2400 / 3600 / 4800 / 6000 r / min, the total iron losses of the motors in the comparative scheme are 5.8W / 12.1W / 21.9W / 30.4W / 32.6W, respectively, while those in the utility model embodiment are 1.81W / 3.67W / 6.08W / 9.05W / 11.47W, respectively. The total iron losses of the utility model embodiment are reduced by 68.8% / 69.6% / 72.2% / 70.2% / 64.8%, respectively, demonstrating significant energy-saving effects.

[0050] Depend on Figure 9 A comparison of stator core iron losses shows that, at corresponding load points of 1200 / 2400 / 3600 / 4800 / 6000 r / min, the stator core iron losses of the comparative schemes are 5.4W / 11.2W / 20W / 27.8W / 28.9W, respectively, while the stator core iron losses of the utility model embodiment are 1.35W / 2.70W / 4.37W / 6.37W / 8.04W. The stator core iron losses of the utility model embodiment are reduced by 74.9% / 75.9% / 78.1% / 77.1% / 72.2%, respectively, demonstrating significant energy-saving effects.

[0051] Depend on Figure 10 A comparison of motor efficiency shows that, at load points of 1200 / 2400 / 3600 / 4800 / 6000 r / min, the motor efficiencies of the comparative scheme are 92.93% / 94.39% / 95.41% / 95.93% / 95.64%, respectively, while the motor efficiencies of the utility model embodiment are 94.20% / 95.03% / 96.30% / 96.92% / 97.27%, respectively. The motor efficiency of the utility model embodiment is increased by 1.4% / 0.7% / 0.9% / 1.0% / 1.7%, respectively.

[0052] As can be seen from the above comparison, the proposed solution significantly reduces iron loss, significantly improves motor efficiency, and achieves remarkable energy-saving and efficiency-enhancing effects.

[0053] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0054] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model. The above description is only a preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. An electric motor, comprising a stator core (1) formed by axially stacking multiple stator laminations (11) and a rotor core (2) formed by axially stacking multiple rotor laminations (21), characterized in that, The stator laminations (11) are amorphous alloy laminations, the rotor laminations (21) are conventional electrical steel laminations, the number of stator laminations (11) is greater than the number of rotor laminations (21), and the thickness of each stator lamination (11) is less than the thickness of each rotor lamination (21).

2. The motor according to claim 1, characterized in that, The thickness of the stator lamination (11) is t1, and the thickness of the rotor lamination (21) is t2, 5.2≤t2 / t1≤41.

7.

3. The motor according to claim 1, characterized in that, The maximum relative permeability of the stator lamination (11) is greater than the maximum relative permeability of the rotor lamination (21).

4. The motor according to claim 3, characterized in that, The maximum relative permeability of the stator lamination (11) is μ1, and the maximum relative permeability of the rotor lamination (21) is μ2, where μ1 ≥ 24 × 10⁻⁶. 4 And μ1 / μ2≥6.

5. The motor according to claim 1, characterized in that, The saturation magnetic flux density of the stator lamination (11) is different from that of the rotor lamination (21).

6. The motor according to claim 5, characterized in that, The saturation magnetic flux density of the stator lamination (11) is Bs1, and the saturation magnetic flux density of the rotor lamination (21) is Bs2, with 0.42≤Bs1 / Bs2≤1.

06.

7. The motor according to claim 1, characterized in that, The stator lamination (11) includes a yoke ring (111) and a plurality of stator teeth (112) on the inner ring wall of the yoke ring (111). Each stator tooth (112) is evenly spaced along the circumference of the yoke ring (111), and a stator slot (113) is formed between adjacent stator teeth (112). Each stator tooth (112) includes a tooth bridge and a tooth shoe. The minimum circumferential width of the tooth bridge is Wmin, and the maximum circumferential width is... Wmax, the average width of the tooth bridge is W1, W1=(Wmin+Wmax) / 2, the outer diameter of the yoke ring (111) is D1, the two opposite circumferential groove walls of the same stator groove (113) extend radially along the stator lamination (11) and intersect the shoe surface of the tooth shoe at a first point and a second point, the circumferential width between the first point and the second point is W2, 0.094≤(W1+W2) / D1≤0.

356.

8. The motor according to any one of claims 1 to 7, characterized in that, The stator core (1) has a split ratio of A, 0.45≤A≤0.68; and / or the stator core (1) has a number of stator slots of Z, 6≤Z≤15.

9. The motor according to any one of claims 1 to 7, characterized in that, The stack height of the stator core (1) is HS, and the stack height of the rotor core (2) is HR, -2mm≤HR-HS≤5mm.

10. A compressor, characterized in that, The motor included in any one of claims 1 to 9.

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