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 iron loss value of each stator lamination is less than the iron loss value of each rotor lamination. This invention enables a rational distribution of magnetic materials between the stator and rotor cores, effectively reducing motor losses and improving motor energy efficiency while lowering motor manufacturing costs.

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 iron loss value of each stator lamination is less than the iron loss value of each rotor lamination.

[0006] In some embodiments, the iron loss of the stator lamination strip used to fabricate the stator laminations when magnetized to 1.5T at 50Hz is less than or equal to 0.6W / Kg.

[0007] In some embodiments, the iron loss of the rotor lamination strip used to fabricate the rotor laminations when magnetized to 1.5T at 50Hz is greater than or equal to 1.8W / Kg and less than or equal to 5.5W / Kg.

[0008] In some embodiments, the number of stator laminations is X, the number of rotor laminations is Y, and 4.6 ≤ X / Y ≤ 40.8.

[0009] In some embodiments, the width of the stator-rotor air gap formed between the stator core and the rotor core is D, and the stator split ratio is E, where 0.8≤D+E≤1.8.

[0010] In some embodiments, the stator laminations have a tooth width of C for each stator tooth, and the total length of the radially outer working surface of the magnets under each magnetic pole of the rotor core is F, where 1.8*C≤F≤3*C.

[0011] In some embodiments, the number of stator slots of the stator core is Z, and the number of magnetic poles of the rotor core is P, where 0.75*P≤Z≤1.75*P.

[0012] 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.

[0013] In some embodiments, the stator laminations are integral laminations.

[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 achieves a reasonable distribution of magnetic materials for the stator and rotor cores, which can reduce motor manufacturing costs while effectively reducing motor losses and improving motor energy efficiency. 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 3 yes 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 diagram of the iron loss per 100 laminations of the stator and rotor laminations in the technical solution of this utility model;

[0028] Figure 11 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.

[0029] The attached figures are labeled as follows:

[0030] 1. Stator core; 11. Stator laminations; 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 iron loss value of each stator lamination 11 is less than the iron loss value of the 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 a reasonable distribution 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] In one specific embodiment, the iron loss value of the stator lamination strip used to fabricate the stator lamination 11 when magnetized to 1.5T at 50Hz is less than or equal to 0.6W / Kg; the iron loss value of the rotor lamination strip used to fabricate the rotor lamination 21 when magnetized to 1.5T at 50Hz is greater than or equal to 1.8W / Kg and less than or equal to 5.5W / Kg. This can further reduce motor losses and improve motor energy efficiency.

[0038] It is understandable that using amorphous materials (i.e., amorphous alloys) 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, there are... It is necessary to further optimize and limit the number X of stator laminations 11 and the number Y of rotor laminations 21 to maximize the cost-effectiveness of the motor by comprehensively considering factors such as motor performance, reliability, and cost. Specifically, the stator core 1 of this application uses amorphous material (laminar thickness 0.012mm~0.038mm) with a lamination factor of 0.85~0.95; the rotor core 2 uses conventional electrical steel material (laminar thickness 0.20mm~0.50mm) with a lamination factor of approximately 0.97. According to the formula: core lamination height * lamination factor / lamination thickness = number of laminations. Generally, the lamination height of stator core 1 is taken to be approximately equal to the lamination height of rotor core 2. Then, the number of stator laminations X = lamination height * (0.85~0.95) / (0.012~0.038), and the number of rotor laminations Y = lamination height * 0.97 / (0.20~0.50). Therefore, 4.6 ≤ X / Y ≤ 40.8.

[0039] In some embodiments, as mentioned above, the width of the stator-rotor air gap formed between the stator core 1 and the rotor core 2 is D (in mm), and the stator split ratio is E (dimensionless, specifically stator inner diameter / stator outer diameter), where 0.8 ≤ D + E ≤ 1.8. It should be noted that in specific designs, the aforementioned stator-rotor air gap width D is set to the same unit (mm), and the corresponding value is substituted into the previous formula. This can more efficiently guide motor design. For example, in a specific embodiment, the aforementioned stator-rotor air gap width is limited to 0.40 mm-1.1 mm, and the split ratio is limited to 0.40-0.70, which satisfies the aforementioned requirement of 0.8 ≤ D + E ≤ 1.8.

[0040] In some embodiments, the tooth width of each stator tooth in the stator lamination 11 is C, and the total length of the radially outer working surface of the magnets (specifically permanent magnets) under each magnetic pole of the rotor core 2 is F, where 1.8*C≤F≤3*C. The units for both the tooth width C and the total length F are mm. Specifically, the radially outer working surface of the magnet refers to the side of the magnet near the N or S pole on the stator side, projected onto a plane perpendicular to the rotation axis of the rotor core 2. Under the same magnetic pole, when there is only one magnet, the projected length of the radially outer working surface of that magnet is the aforementioned F. When there are multiple magnets, the sum of the projected lengths of the radially outer working surfaces of each magnet is the aforementioned F.

[0041] In this technical solution, limiting the key dimensions of the amount of magnets (i.e., the aforementioned parameter F) and the stator laminations (i.e., the aforementioned parameter C) maximizes the utilization rate of motor materials and achieves superior motor performance. Within the aforementioned limits of this application, the core has a suitable magnetic flux density, and the utilization rate of both magnets and core materials is high, resulting in superior motor performance. Conversely, a ratio that is too small means insufficient magnet usage, leading to a low stator core magnetic flux density (i.e., low stator core material utilization), or an excessively wide tooth width, resulting in a reduced slot area, ultimately leading to increased copper losses and reduced motor efficiency. Conversely, a ratio that is too large means excessive magnet usage but saturated stator core magnetic flux density (i.e., excess magnets and low material utilization), or an excessively narrow tooth width, leading to an excessively high stator core magnetic flux density, ultimately leading to increased iron losses and reduced motor efficiency.

[0042] In some embodiments, the number of stator slots in the stator core 1 is Z, and the number of magnetic poles in the rotor core 2 is P, where 0.75*P≤Z≤1.75*P. Verification has shown that when Z is less than the aforementioned range, the number of slots is too small and the number of poles is too large, resulting in prominent high-frequency electromagnetic noise, high eddy current losses in the permanent magnets, and high rotor cost; when Z is greater than the aforementioned range, the number of slots is too large and the number of poles is too small, resulting in significant low- and mid-frequency electromagnetic noise and vibration, high stator iron losses, and high cost.

[0043] 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.

[0044] In some embodiments, the stator laminations 11 are integral laminations, see details below. Figure 2 As shown, the stator lamination 11 in this application includes a yoke ring (not indicated in the figure) and a plurality of stator teeth on the radial inner ring wall of the yoke ring. The stator groove is formed between two adjacent stator teeth. Specifically, it is formed by punching and shearing the stator lamination strip as described above, which is more convenient and simple in the stacking process.

[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 number of rotor poles P is 8, Z / P = 1.5, the stack height of both the stator core and the rotor core is 50mm, the number of stator laminations X is 1800, the number of rotor laminations Y is 163, X / Y = 11; D+E = 1.12, F / C = 2.38; the iron loss of the stator lamination strip magnetized to 1.5T at 50Hz is approximately 0.32W / Kg, and the iron loss of the rotor lamination strip magnetized to 1.5T at 50Hz is approximately 2.3W / Kg;

[0048] Comparing motor efficiency MAP charts ( 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 exceeds 97% (within the range of 97 contour lines, the measured maximum is 97.2%), and the efficiency in the region exceeding 95% (within the range of 95 contour lines) is also greatly improved compared to the comparative scheme, with significant efficiency improvement.

[0049] Depend on Figure 8 A comparison of the total iron losses of the motor shows that, at the corresponding load points of 1200 / 2400 / 3600 / 4800 / 6000 r / min, the total iron losses of the comparative schemes are 5.8W / 12.1W / 21.9W / 30.4W / 32.6W, respectively, while the total iron losses of the present invention are 1.6W / 3.46W / 6.24W / 8.75W / 9.61W. The total iron losses of the present invention are reduced by 72.4% / 71.4% / 71.5% / 71.2% / 70.5%, respectively. It can be seen that the iron loss reduction of the present application scheme is more than 70%, and the energy-saving effect is significant.

[0050] Depend on Figure 9 A comparison of stator core losses shows that, at load points of 1200 / 2400 / 3600 / 4800 / 6000 r / min, the stator core losses of the comparative schemes are 5.4W / 11.2W / 20W / 27.8W / 28.9W, respectively, while the stator core losses of the present invention are 1.25W / 2.52W / 4.39W / 6.09W / 6.35W. The stator core losses of the present invention are reduced by 76.8% / 77.5% / 78.1% / 78.1% / 78.0%, respectively. It can be seen that the stator core loss reduction of the present application scheme is over 76%, and the energy-saving effect is significant.

[0051] In this utility model embodiment, at load points of 1200 / 2400 / 3600 / 4800 / 6000 r / min, the total iron loss is 1.6W / 3.46W / 6.24W / 8.75W / 9.61W, and the stator core iron loss is 1.25W / 2.52W / 4.39W / 6.09W / 6.35W. Subtracting the stator core iron loss from the total iron loss gives the rotor core iron loss, which is 0.35W / 0.94W / 1.85W / 2.66W / 3.26W respectively. In this utility model embodiment, the stator core iron loss is... The stator core has a stack height of 50mm, a stacking factor of 0.90, and a strip thickness of 0.025mm, meaning the stator has 1800 laminations. The iron losses per 100 stator laminations are 0.07W / 0.14W / 0.24W / 0.34W / 0.35W respectively. The rotor core has a stack height of 50.5mm, a stacking factor of 0.97, and a strip thickness of 0.3mm, meaning the rotor has 163 laminations. The iron losses per 100 rotor laminations are 0.21W / 0.58W / 1.13W / 1.63W / 2.00W respectively. Therefore, the iron loss per stator lamination is less than the iron loss per rotor lamination. (See [reference needed]). Figure 11 As shown, the energy-saving and efficiency-improving effects of this application are significant.

[0052] 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.

[0053] 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 machine comprising a stator core (1) formed by axially stacking a plurality of stator laminations (11) and a rotor core (2) formed by axially stacking a plurality of 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 iron loss value of each stator lamination (11) is less than the iron loss value of each rotor lamination (21).

2. The electric machine of claim 1, wherein, The iron loss of the stator lamination strip used to make the stator lamination (11) when magnetized to 1.5T at 50Hz is less than or equal to 0.6W / Kg.

3. The electric machine of claim 1, wherein, The iron loss value of the rotor lamination strip used to make the rotor lamination (21) when magnetized to 1.5T at 50Hz is greater than or equal to 1.8W / Kg and less than or equal to 5.5W / Kg.

4. The electric machine of claim 1, wherein, The number of stator laminations (11) is X, and the number of rotor laminations (21) is Y, where 4.6 ≤ X / Y ≤ 40.

8.

5. The electric machine of claim 1, wherein, The width of the air gap between the stator core (1) and the rotor core (2) is D, and the stator split ratio is E, where 0.8≤D+E≤1.

8.

6. The electric machine of claim 1, wherein, The stator lamination (11) has a tooth width of C for each stator tooth, and the total length of the radial outer working surface of the magnet under each magnetic pole of the rotor core (2) is F, where 1.8*C≤F≤3*C.

7. The electric machine of claim 1, wherein, The number of stator slots of the stator core (1) is Z, and the number of magnetic poles of the rotor core (2) is P, where 0.75*P≤Z≤1.75*P.

8. The electric machine of claim 1, wherein, 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.

9. The electric machine of claim 1, wherein, The stator laminations (11) are integral laminations.

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

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