Motor core, scroll compressor and refrigeration equipment

Abstract

The present invention provides a motor core, a scroll compressor and a refrigeration device, and relates to the technical field of compressors. The motor core of the present invention includes a rotor core and a stator core sleeved thereon, and is characterized in that the inner surface of the stator core and / or the outer surface of the rotor core is a conical surface, so that an air gap is formed between the stator core and the rotor core, the width of which gradually increases along the axial direction of the core. Based on the technical solution of the present invention, the air gap unevenness is reduced, and the increase in the air gap magnetic resistance is not too large. An optimization is achieved between the air gap magnetic resistance and the air gap uniformity, thereby reducing the fluctuation rate of the air gap magnetic resistance, resulting in a decrease in the fluctuation rate of the radial electromagnetic force, and ultimately effectively reducing the electromagnetic vibration and electromagnetic noise of the entire compressor.

Description

Technical Field

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

[0002] The motor core is an important component of the compressor. In particular, the scroll compressor has the outstanding advantages of low vibration, few parts and high reliability, and is widely used in the field of refrigeration and air conditioning. Similar to other closed refrigeration compressors, the basic structure of the scroll compressor is also composed of a mechanical pump unit and a motor unit enclosed in a fully enclosed shell. The mechanical pump unit completes the suction, compression and discharge of the refrigerant, and the motor unit provides the required power. Usually, the energy supply of the motor unit and the mechanical pump unit needs to be transmitted by the main shaft. One end of this shaft is shrink-fitted into the motor rotor, and the other end drives the pump body through a certain structure. The motor rotor is provided with a motor stator, and the motor stator is installed on the shell. For scroll compressors, two rolling bearings (called main and secondary bearings) are generally used to position and support the main shaft.

[0003] It's difficult to achieve perfect alignment between the axes of the main and secondary bearings; there's a certain degree of deviation, measured by coaxiality. Consequently, misalignment between the main shaft and secondary bearings will cause the axis of the main shaft and the rotor, which is shrink-fitted onto the main shaft, to tilt relative to the housing and the axis of the motor's stator core. This directly results in an uneven gap between the stator and rotor. This uneven gap between the stator and rotor increases radial electromagnetic force fluctuations in the motor, leading to increased electromagnetic noise. Electromagnetic noise typically occurs in the mid- and low-frequency bands. Mid- and low-frequency noise is highly penetrating and difficult to shield or eliminate, making its mitigation crucial. Summary of the Invention

[0004] In response to the problem that the air gap between the stator and the rotor of the scroll compressor in the above-mentioned prior art is uneven, which will lead to increased fluctuations in the radial electromagnetic force of the motor and thus increased electromagnetic noise, the present application proposes a motor core, an eddy current compressor and a refrigeration equipment that can reduce the unevenness of the air gap and reduce electromagnetic noise.

[0005] In a first aspect, the present invention proposes a motor core, comprising a rotor core and a stator core sleeved thereon, wherein the inner surface of the stator core and / or the outer surface of the rotor core is a conical surface, so that an air gap is formed between the stator core and the rotor core, the width of which gradually increases along the axial direction of the core.

[0006] In one embodiment, an angle θ is formed between the inner surface of the stator core and the outer surface of the rotor core, and θ satisfies the following relationship:

[0007]

[0008] Where C is the coaxiality of the first and second bearings corresponding to the ends of the main shaft on which the rotor core is located, L is the distance between the first and second bearings, and λ is a constant less than 1. This embodiment limits the inclination of the conical surface of the rotor core or stator core, reduces air gap unevenness, and avoids excessive increases in air gap magnetic resistance, achieving an optimal balance between air gap magnetic resistance and air gap uniformity.

[0009] In one embodiment, in the formula, the value range of λ is 0.3 to 0.6. Through this embodiment, the value range of the λ constant less than 1 is further determined.

[0010] In one embodiment, the inner surface of the stator core and the outer surface of the rotor core are both conical surfaces. This embodiment allows conical surfaces to be machined on the inner surface of the stator core and the outer surface of the rotor core, respectively. Furthermore, the conical surfaces of the stator core and the rotor core are inclined in opposite directions, thereby reducing the process requirements when machining miniature rotor cores or stator cores.

[0011] In one embodiment, the conical angle of the conical surface of the stator core is θ', and the conical angle of the conical surface of the rotor core is θ", satisfying θ' + θ" = θ. Through this embodiment, the conical angle that originally needs to be processed separately on the stator core or the rotor core is divided into two parts, which are processed separately on the stator core and the rotor core.

[0012] In one embodiment, the cone angle of the conical surface of the stator core is equal to the cone angle of the conical surface of the rotor core.

[0013] In one embodiment, the generatrix of the conical surface is a straight line or a curve.

[0014] In one embodiment, the width of the air gap increases uniformly along the axial direction of the core. Through this embodiment, the surface smoothness of the rotor core and the stator core is ensured, and noise is reduced.

[0015] In a second aspect, the present invention provides a scroll compressor comprising the above-mentioned motor core.

[0016] In a third aspect, the present invention provides an intelligent device comprising the scroll compressor described above.

[0017] The above technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved.

[0018] The motor core, scroll compressor and refrigeration equipment provided by the present invention have at least the following beneficial effects compared with the prior art:

[0019] The air gap width between the stator core and the rotor core of the present invention gradually increases along the axial direction of the core, which not only reduces the air gap unevenness, but also prevents the increase of the air gap magnetic resistance from being too large. An optimization is achieved between the air gap magnetic resistance and the air gap uniformity, thereby reducing the fluctuation rate of the air gap magnetic resistance, resulting in a decrease in the fluctuation rate of the radial electromagnetic force, and ultimately effectively reducing the electromagnetic vibration and electromagnetic noise of the entire compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, wherein:

[0021] Figure 1 A top view schematic diagram showing the increase in the air gap between the stator core and the rotor core;

[0022] Figure 2 A schematic front cross-sectional view showing the stator core with an increased inner diameter;

[0023] Figure 3 A schematic front cross-sectional view showing the reduced outer diameter of the rotor core;

[0024] Figure 4 A schematic diagram showing the installation positions of the stator core and the rotor core of the present invention is shown;

[0025] Figure 5 A comparative schematic diagram showing the spindle axis tilt;

[0026] Figure 6 A top-down comparison diagram showing the rotor core offset relative to the stator core is shown;

[0027] Figure 7 A schematic diagram showing the main cross-section comparison when the rotor core is offset relative to the stator core;

[0028] In the drawings, like reference numerals are used for like parts, but the drawings are not necessarily true to scale.

[0029] Reference numerals:

[0030] 10- rotor core, 20- stator core, 30- main shaft, 31- first bearing, 32- second bearing. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings.

[0032] Example 1

[0033] The present invention proposes a motor core, including a rotor core 10 and a stator core 20 sleeved thereon, wherein the inner surface of the stator core 20 and / or the outer surface of the rotor core 10 are conical surfaces, so that an air gap is formed between the stator core 20 and the rotor core 10, the width of which gradually increases along the axial direction of the core.

[0034] Specifically, as attached Figure 1-3 The air gap between the stator core 20 and the rotor core 10 gradually increases along the axial direction of the core, which not only reduces the air gap unevenness, but also prevents the increase of the air gap magnetic resistance from being too large. An optimization is achieved between the air gap magnetic resistance and the air gap uniformity, thereby reducing the fluctuation rate of the air gap magnetic resistance, resulting in a decrease in the fluctuation rate of the radial electromagnetic force, and ultimately effectively reducing the electromagnetic vibration and electromagnetic noise of the entire compressor.

[0035] It should be further clarified that electromagnetic noise is essentially still a type of mechanical noise. It is simply mechanical noise caused by the mechanical vibration caused by the electromagnetic force acting on the motor core. Because the generation mechanism of electromagnetic force is completely different from mechanical force, electromagnetic noise is listed as a separate noise type. The air gap between the stator core 20 and the rotor core 10 has a significant impact on electromagnetic noise. In fact, the air gap with a radial length constitutes the most important magnetic resistance in the motor's magnetic circuit. The motor's magnetic field energy is essentially concentrated in the air gap magnetic resistance. The motor's magnetic flux is determined by the motor's magnetomotive force divided by the magnetic resistance. When the air gap length changes very little, that is, the change in the air gap magnetic resistance is also very small, the change in magnetic flux is very small, and the corresponding change in electromagnetic force is very small. According to vibration theory, it is known that the cause of large vibration of mechanical components is not the magnitude of the external force, but the magnitude of the change in the external force. Therefore, the magnitude of the change in air gap magnetic resistance, rather than the magnitude of the air gap magnetic resistance itself, is the decisive factor in determining the change in electromagnetic force and, therefore, the magnitude of electromagnetic noise.

[0036] From the above, we can see that the unevenness of the air gap distribution between the stator and rotor of the motor is an important factor affecting electromagnetic noise. Reducing the unevenness of the air gap between the stator and rotor, also known as the fluctuation rate, can effectively suppress electromagnetic noise. Figure 6 and 7 , Figure 6 and Figure 7 The structure on the left side is a schematic diagram showing that the inner surface of the stator core 20 and the outer surface of the rotor core 10 are both cylindrical. The structure on the right side is a top view schematic diagram and a front cross-sectional view when the stator core 20 and the rotor core 10 are relatively tilted. At this time, the air gap unevenness between the stator core 20 and the rotor core 10 is recorded as δ, which satisfies the following formula (2):

[0037]

[0038] In (2) above, C max is the maximum air gap width, C minis the minimum air gap width, D is the inner diameter of the stator core 20, d is the outer diameter of the rotor core 10, and (Dd) / 2 is the average air gap value.

[0039] According to the above formula (2), if the inner diameter of the stator core 20 is increased by 2Δ and the outer diameter of the rotor core 10 remains unchanged, the maximum air gap and the minimum air gap will each increase by Δ. At this time, the air gap unevenness is δ', which satisfies the following formula (3):

[0040]

[0041] From the comparison between formula (2) and formula (3), it can be seen that the value of δ' is smaller than the value of δ. After the inner diameter of the stator core 20 increases by 2Δ, the unevenness of the air gap between the stator core 20 and the rotor core 10 is reduced, which will lead to a reduction in the radial electromagnetic force fluctuation and thus reduce the corresponding electromagnetic noise.

[0042] Similarly, according to the above formula (2), if the outer diameter of the rotor core 10 is reduced by 2Δ and the inner diameter of the stator core 20 is kept unchanged, the maximum air gap and the minimum air gap will increase by Δ respectively. At this time, the air gap unevenness is δ", which satisfies the following formula (4):

[0043]

[0044] It can be seen that the air gap non-uniformity will also be reduced, which will also lead to a reduction in radial electromagnetic force fluctuations, thereby reducing the corresponding electromagnetic noise. The above is the scientific principle on which this application is based.

[0045] In addition, in reality, the inclination angle of the main shaft 30 caused by the misalignment of the axes of the first bearing 31 and the second bearing 32 is generally around 0.1°, and the Δ value when the stator core 20 or the rotor core 10 is designed to be conical is generally less than 0.15 mm. The drawings of this application are intended to illustrate the problem and highlight the key points, and the actual situation is magnified several times.

[0046] Example 2

[0047] This embodiment is a further optimization based on the first embodiment as follows: an angle θ is formed between the inner surface of the stator core 20 and the outer surface of the rotor core 10, satisfying the following relationship (1):

[0048]

[0049] In the above formula (1), λ=0.3-0.6, C is the coaxiality of the first bearing 31 and the second bearing 32 on both sides of the rotor core 10, which are sleeved on the main shaft 30 passing through the rotor core 10, and L is the distance between the first bearing 31 and the second bearing 32. Figure 5The left side of the figure shows the positional relationship between the first bearing 31 and the second bearing 32 and the stator core 20 when they are theoretically coaxial. The right side shows the positional relationship between the first bearing 31 and the second bearing 32 and the stator core 20 when they are not coaxial. The inclination of the conical surface of the rotor core 10 or the stator core is limited to reduce the air gap unevenness while avoiding excessive increase in the air gap magnetic resistance, thereby achieving an optimization between the air gap magnetic resistance and air gap uniformity. When the inner surface of the stator core 20 is a conical surface, the outer surface of the rotor core 10 is cylindrical; when the outer surface of the rotor core 10 is conical, the inner surface of the stator core 20 is cylindrical.

[0050] Specifically, the angle θ between the inner surface of the stator core 20 and the outer surface of the rotor core 10 is more specifically described as follows: after the stator core 20 and the rotor core 10 are assembled, a cross-section is obtained by cutting along the axis, as shown in the attached figure. Figure 2 and attached Figure 3 , θ is the angle between the outer contour of the stator core 20 and the inner contour of the rotor core 10. If the inner diameter of the stator core 20 is simply increased in the axial direction, or the outer diameter of the rotor core 10 is simply decreased, that is, if the stator core 20 or rotor core 10 remains cylindrical after the changes in size, the air gap reluctance will become excessively large, resulting in increased motor power and reduced efficiency.

[0051] Furthermore, the values of λ are 0.3, 0.4, 0.5, and 0.6, etc. The value of λ needs to be determined based on experience, which reflects the fact that the angle determined by the parameters C and L in formula (1) is a probabilistic event, that is, the angle determined by C and L actually has a low probability of occurring. Therefore, the actual determination of the cone angle θ needs to be discounted, and therefore needs to be multiplied by a coefficient λ less than 1.

[0052] Example 3

[0053] This embodiment is a further optimization based on the second embodiment as follows: the inner surface of the stator core 20 and the outer surface of the rotor core 10 are both conical surfaces. The inner surface of the stator core 20 and the outer surface of the rotor core 10 can be processed into conical surfaces respectively, and the inclination direction of the conical surface of the stator core 20 is opposite to that of the conical surface of the rotor core 10, which reduces the process requirements when the micro rotor core 10 or the stator core 20 needs to be processed. The cone angle of the conical surface of the stator core 20 is θ', and the cone angle of the conical surface of the rotor core 10 is θ", which satisfies the condition that θ'+θ"=θ. Furthermore, θ'=θ", for a micro compressor, when one of the components of the stator core 20 or the rotor core 10 is more difficult to process, the cone angle of the component with greater processing difficulty can be set to be smaller than that of the other component that is easier to process. The cone angle that originally needs to be processed separately on the stator core 20 or the rotor core 10 is divided into two parts, which are processed on the stator core 20 and the rotor core 10 respectively.

[0054] Specifically, for large compressor motors, where process requirements are met, a conical surface can be machined simultaneously on the inner surface of the stator core 20 or the outer surface of the rotor core 10. The sum of the cone angles of the conical surfaces of the stator core 20 and the rotor core 10 is equal to or slightly smaller than the cone angle when a conical surface is machined on either the stator core 20 or the rotor core 10. When the conical surfaces are machined simultaneously on the inner surface of the stator core 20 or the outer surface of the rotor core 10, the inner diameter of the stator core 20 gradually increases in the axial direction, while the outer diameter of the rotor core 10 gradually decreases in the same direction.

[0055] The angle between the axes of the rotor core 10 and the stator core 20 is 0.05° to 0.15°. Specifically, the rotor core 10 is shrink-fitted onto the main shaft 30. The first bearing 31 and the second bearing 32 provided on the main shaft 30 are located on either side of the rotor core 10. It is difficult for the axes of the first bearing 31 and the second bearing 32 to completely coincide with each other, and there is a certain deviation. As a direct result, the axis of the rotor core 10 forms a certain angle with the axial direction of the stator core 20. Other undescribed parts are the same as those in the above embodiment and are not repeated here.

[0056] Example 4

[0057] The generatrix of the conical surface is a straight line or a curve. This satisfies the requirement for the air gap width to gradually increase. The air gap width increases uniformly along the core axis, ensuring surface smoothness between the rotor core 10 and the stator core 20 and reducing wind resistance. Other undescribed portions are identical to those in the above embodiment and are therefore not further elaborated.

[0058] Example 5

[0059] The present invention provides a scroll compressor, comprising the above-mentioned motor core, and thus having all the technical effects possessed by the motor core.

[0060] Example 6

[0061] The present invention proposes an intelligent device, comprising the above-mentioned scroll compressor, and thus having all the technical effects possessed by the scroll compressor.

[0062] In the description of the present invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "back", "inside", "outside", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0063] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be employed in conjunction with other described embodiments.

Claims

1. A motor core, comprising a rotor core and a stator core sleeved thereon, characterized in that: The inner surface of the stator core and the outer surface of the rotor core are conical surfaces, so that an air gap is formed between the stator core and the rotor core, the width of which gradually increases along the axial direction of the core; The conical angle of the conical surface of the stator core is θ', the conical angle of the conical surface of the rotor core is θ", and an angle θ is formed between the inner surface of the stator core and the outer surface of the rotor core, satisfying θ'+θ"=θ.

2. The motor core according to claim 1, characterized in that: θ satisfies the following relationship: Wherein, C is the coaxiality of the first bearing and the second bearing corresponding to the two ends of the main shaft where the rotor core is located, L is the distance between the first bearing and the second bearing, and λ is a constant less than 1.

3. The motor core according to claim 2, characterized in that: The value range of λ is 0.3 to 0.

6.

4. The motor core according to claim 1, characterized in that The cone angle of the conical surface of the stator core is equal to the cone angle of the conical surface of the rotor core.

5. The motor core according to claim 1, characterized in that: The generatrix of the conical surface is a straight line or a curve.

6. The motor core according to claim 1, characterized in that The width of the air gap increases uniformly along the axial direction of the iron core.

7. A scroll compressor, characterized in that: The motor core comprises the motor core according to any one of claims 1 to 6.

8. A refrigeration device, characterized in that: Comprising the scroll compressor as claimed in claim 7.

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