Rotors, motors and compressors

Abstract

This application relates to the field of compressor technology, providing a rotor, motor, and compressor. The rotor includes a main end, a middle section, and a secondary end distributed sequentially along the axial direction. A first rotor segment extends from the secondary end to the middle section, and a second rotor segment extends from the main end to the middle section. The outer diameter of the first rotor segment gradually decreases from the middle section away from the second rotor segment, and the outer diameter of the second rotor segment also gradually decreases from the middle section away from the first rotor segment. A first inclination angle α1 is formed between the outer circumferential surface of the first rotor segment and the outer circumferential surface of the middle section, and a second inclination angle α2 is formed between the outer circumferential surface of the second rotor segment and the outer circumferential surface of the middle section, satisfying the condition: K = α1 / α2 ≥ 1. This application can optimize the center of gravity according to different displacements by setting K to at least greater than 1. Different values ​​of K result in different degrees of axial eccentricity, which alleviates the coaxiality problem caused by high-stack rotors to a certain extent, and also reduces deflection.

Description

Technical Field

[0001] This application relates to the field of compressor technology, and more particularly to a rotor, motor and compressor. Background Technology

[0002] With rising raw material prices and the implementation of the new national energy efficiency standards, there is a clear trend towards miniaturization and high stacking of compressor motors. Problems such as large deflection caused by eccentricity during compressor operation, poor rotor coaxiality, and abnormal noise during startup are hindering the development of compressors and motors. Summary of the Invention

[0003] The main purpose of this application is to provide a rotor, motor and compressor that aims to solve the problems of compressor eccentricity, large deflection and poor high rotor coaxiality.

[0004] In a first aspect, this application provides a rotor comprising a main end, a middle section, and a secondary end distributed sequentially along the axial direction. The section between the secondary end and the middle section is a first rotor segment, and the section between the main end and the middle section is a second rotor segment. The outer diameter of the first rotor segment gradually decreases from the middle section in a direction away from the second rotor segment, and the outer diameter of the second rotor segment gradually decreases from the middle section in a direction away from the first rotor segment. The first inclination angle of the outer circumferential surface of the first rotor segment relative to the outer circumferential surface of the middle section is α1, and the second inclination angle of the outer circumferential surface of the second rotor segment relative to the outer circumferential surface of the middle section is α2. α1 and α2 satisfy the following condition: K = α1 / α2 ≥ 1.

[0005] In one optional scheme of this embodiment, 1≤K≤2.

[0006] In one optional embodiment, the rotor further includes a plurality of rotor skewers arranged along the circumferential direction. The angle of the rotor skewers is β, and β, α1, and α2 satisfy the following conditions: α1 < β, α2 < β.

[0007] In one optional embodiment, the outer circumference of the rotor is stepped, and the outer circumference includes: a first step portion; and a second step portion, wherein the orthographic projection of the second step portion along the axial direction covers the orthographic projection of the first step portion along the axial direction; wherein the total length of the rotor along its axial direction is L, the distance between the centerline of the first step portion and the end face of the main end is d1, and the distance between the centerline of the second step portion and the end face of the main end is d2, then L, d1, and d2 must satisfy the following conditions: d1 < 2 / L, d2 < 2 / L.

[0008] In one optional embodiment, the total length of the first segment along its axial direction is L1, and the total length of the second segment along its axial direction is L2. Then d1, d2, L1 and L2 must satisfy the following conditions: d2≤d1, L2≥L1.

[0009] In one optional embodiment, L1 and L2 also need to satisfy the following conditions:

[0010] In one optional embodiment, the rotor includes a rotor core, which comprises a plurality of rotor laminations stacked axially and having different outer diameters.

[0011] In one optional embodiment, the rotor slot is any one of an open slot, a closed slot, a semi-open slot, and a semi-closed slot.

[0012] In a second aspect, this application provides an electric motor, comprising: the rotor described in any one of the first aspects.

[0013] Thirdly, this application provides a compressor that includes the motor described in the second aspect.

[0014] This application provides a rotor, comprising a main end, a middle section, and a secondary end distributed sequentially along the axial direction. The section between the secondary end and the middle section is a first rotor segment, and the section between the main end and the middle section is a second rotor segment. The outer diameter of the first rotor segment gradually decreases from the middle section in a direction away from the second rotor segment, and the outer diameter of the second rotor segment gradually decreases from the middle section in a direction away from the first rotor segment. The first inclination angle of the outer circumferential surface of the first rotor segment relative to the outer circumferential surface of the middle section is α1, and the second inclination angle of the outer circumferential surface of the second rotor segment relative to the outer circumferential surface of the middle section is α2. α1 and α2 satisfy the following condition: K = α1 / α2 ≥ 1. On the one hand, the cross-sectional area of ​​the rotor at the middle is larger than that at other locations, which effectively reduces stress concentration in the middle of the rotor, weakens radial imbalance, increases the overall strength of the rotor, and reduces deflection and eccentric wear. Conversely, the cross-sectional areas at the main and secondary ends of the rotor are smaller than those at other locations, which effectively increases the air gap between the stator and rotor, reduces the first-order inertial force of the rotor caused by static eccentricity between the rotor and stator, and further reduces electromagnetic noise during startup and noise vibration during actual operation. On the other hand, the K value can be changed according to the different displacements of the compressor pump body. The larger the displacement, the greater the pump body resistance torque, and the larger the proportion of counterweight that needs to be balanced. The larger the K value, the closer the rotor's center of gravity is to the main end and the auxiliary end of the rotor. When K=1, the rotor's center of gravity is in the middle of the rotor, and the main end and auxiliary end of the rotor have the same counterweight. When K>1, the rotor's center of gravity is in the second rotor segment. The larger the K value, the closer the rotor's center of gravity is to the main end. By controlling the K value, the position of the rotor's counterweight can be different, thereby adjusting the position of the rotor's center of gravity. The rotor's center of gravity can be optimized according to different compressor pump displacements, effectively reducing the center of gravity when the rotor rotates. Furthermore, different rotor center of gravity positions will also lead to different degrees of axial eccentricity, thereby improving the problem of eccentricity. To a certain extent, this alleviates the coaxiality problem caused by high-stack rotors, while also reducing deflection and eccentric wear. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A perspective view of a rotor provided in an embodiment of this application is shown;

[0018] Figure 2 A front view of a rotor provided in an embodiment of this application is shown;

[0019] Figure 3 for Figure 2 A magnified view of a portion of point A in the middle.

[0020] The annotations in the attached figures are explained as follows:

[0021] 10. Rotor core; 1. Main end; 2. Secondary end; 3. Middle section; 31. First differential section; 32. Second differential section; 4. First rotor section; 5. Second rotor section. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] With rising raw material prices and the implementation of the new national energy efficiency standards, there is a clear trend towards miniaturization and high stacking of compressor motors. Problems such as large deflection caused by eccentricity during compressor operation, poor rotor coaxiality, and abnormal noise during startup are hindering the development of compressors and motors.

[0024] In view of this, embodiments of this application provide a rotor, a motor, and a compressor to solve the above-mentioned technical problems.

[0025] Examples of rotors

[0026] Please see Figures 1-3As shown, this application provides a rotor, including a main end 1, a middle section 3, and a secondary end 2 distributed sequentially along the axial direction. The section between the secondary end 2 and the middle section 3 is a first rotor segment 4, and the section between the main end 1 and the middle section 3 is a second rotor segment 5. The outer diameter of the first rotor segment 4 gradually decreases from the middle section 3 in a direction away from the second rotor segment 5, and the outer diameter of the second rotor segment 5 gradually decreases from the middle section 3 in a direction away from the first rotor segment 4. The first inclination angle of the outer peripheral surface of the first rotor segment 4 relative to the outer peripheral surface of the middle section 3 is α1, and the second inclination angle of the outer peripheral surface of the second rotor segment 5 relative to the outer peripheral surface of the middle section 3 is α2. α1 and α2 satisfy the following condition: K = α1 / α2 ≥ 1.

[0027] On the one hand, the cross-sectional area of ​​the rotor at the middle is larger than that at other locations, which effectively reduces stress concentration in the middle of the rotor, weakens radial imbalance, increases the overall strength of the rotor, and reduces deflection and eccentric wear. Conversely, the cross-sectional areas at the main and secondary ends of the rotor are smaller than those at other locations, which effectively increases the air gap between the stator and rotor, reduces the first-order inertial force of the rotor caused by static eccentricity between the rotor and stator, and further reduces electromagnetic noise during startup and noise vibration during actual operation. On the other hand, the K value can be changed according to the different displacements of the compressor pump body. The larger the displacement, the greater the pump body resistance torque, and the larger the proportion of counterweight that needs to be balanced. The larger the K value, the closer the rotor's center of gravity is to the main end and the auxiliary end of the rotor. When K=1, the rotor's center of gravity is in the middle of the rotor, and the main end and auxiliary end of the rotor have the same counterweight. When K>1, the rotor's center of gravity is in the second rotor segment. The larger the K value, the closer the rotor's center of gravity is to the main end. By controlling the K value, the position of the rotor's counterweight can be different, thereby adjusting the position of the rotor's center of gravity. The rotor's center of gravity can be optimized according to different compressor pump displacements, effectively reducing the center of gravity when the rotor rotates. Furthermore, different rotor center of gravity positions will also lead to different degrees of axial eccentricity, thereby improving the problem of eccentricity. To a certain extent, this alleviates the coaxiality problem caused by high-stack rotors, while also reducing deflection and eccentric wear.

[0028] Preferably, the value of K should be in the range of 1≤K≤2. The value of K depends on the different displacements of the compressor. Therefore, the value of K can be adjusted according to the actual power of the compressor and the refrigeration conditions. When the value of K is less than 1, the rotor center of gravity is located in the first rotor section. The rotor center of gravity is too high, which cannot guarantee the balance and stability of the rotor during rotation. Therefore, it cannot solve the problems of large deflection, poor coaxiality of the high rotor and abnormal noise during startup caused by the eccentricity of the compressor during operation. When the value of K is greater than 2, the rotor center of gravity is located in the second rotor section, and the rotor center of gravity is close to the main end. Therefore, the rotor center of gravity is too low, which cannot guarantee the rotation speed of the rotor and the displacement of the compressor. In summary, the value of K is in the range of 1≤K≤2, which can guarantee the displacement requirements of the compressor and alleviate the problem of poor coaxiality caused by high-stack rotors, and reduce deflection and eccentric wear.

[0029] Furthermore, in order to ensure the working efficiency of the rotor and the starting performance of the compressor, the rotor also includes multiple rotor skew slots opened along the circumferential direction. The angle of the rotor skew slot is β. Then β, α1 and α2 must satisfy the following conditions: α1 < β, α2 < β. The rotor skew slot angle is set by the actual stator skew slot angle in accordance with production needs.

[0030] It should be noted that the bottom and top shapes of the rotor skew slots in this solution are not limited, such as circular, flat, square, and pointed. The slot type of the rotor skew slots can be a single squirrel cage slot or a double squirrel cage slot. The shape of the rotor skew slots can be any of the following: open slot, closed slot, semi-open slot, and semi-closed slot. There are no restrictions on the area, size, casting material, and forming method of the rotor skew slots. The number of rotor skew slots can be set according to the rotor's own parameters.

[0031] In this embodiment, the outer circumference of the rotor is arranged in a stepped shape, and the outer circumference of the rotor includes multiple stepped sections. Taking two stepped sections as an example, the outer circumference of the rotor has: a first stepped section 31; and a second stepped section 32. The orthographic projection of the second stepped section 32 along the axial direction covers the orthographic projection of the first stepped section 31 along the axial direction. The total length of the rotor along its axial direction is L, the distance between the centerline of the first stepped section 31 and the end face of the main end 1 is d1, and the distance between the centerline of the second stepped section 32 and the end face of the main end 1 is d2. Then L, d1, and d2 must satisfy the following conditions: d1 < 2 / L, d2 < 2 / L.

[0032] Since the maximum axial eccentricity and the maximum bending eccentricity of the rotor both occur near the center 3 of the rotor, this embodiment changes the rotor's center of gravity by controlling the distance between the centerline of each step section and the end face of the main end 1, thereby changing the relative position of each step section and the main end 1. Specifically, when At that time, the first segment 31 is located in the middle part 3 of the rotor, biased towards the secondary end 2, that is, most of the first segment 31 falls on the first rotor segment 4, and a small part falls on the second rotor segment 5. At that time, the first segment 31 is located in the middle part 3 of the rotor, biased towards the main end 1, that is, most of the first segment 31 falls on the second rotor segment 5, and a small part falls on the first rotor segment 4. At that time, the first segment 31 is located in the middle of the rotor 3, with its centerline coinciding with the rotor centerline, meaning that half of the first segment 31 falls on the first rotor segment 4 and the other half falls on the second rotor segment 5; when At that time, the second stage difference 32 is located in the middle part 3 of the rotor, biased towards the secondary end 2, that is, most of the second stage difference 32 falls on the first rotor segment 4, and a small part falls on the second rotor segment 5. At that time, the second stage difference 32 is located in the middle part 3 of the rotor, biased towards the main end 1, that is, most of the second stage difference 32 falls on the second rotor segment 5, and a small part falls on the first rotor segment 4. At that time, the second segment 32 is located in the middle part 3 of the rotor, and its centerline coincides with the centerline of the rotor. That is, half of the second segment 32 falls on the first rotor segment 4 and the other half falls on the second rotor segment 5.

[0033] Therefore, based on K>1, when d1<2 / L and d2<2 / L, the first step 31 and the second step 32 are both located in the rotor middle 3 facing the main end 1, which can enhance the strength of the rotor middle 3 and reduce the wear on the compressor crankshaft. At the same time, by controlling the position and length of multiple step parts, the shaft counterweight can be controlled to optimize the low-frequency vibration during compressor operation, thereby reducing vibration and noise.

[0034] Meanwhile, the stepped structure of the rotor can control the shaft counterweight by changing the length of the stepped section, thereby reducing the compressor deflection. The first stepped section 31 and the second stepped section 32 reduce the stress in the middle part 3 of the rotor, enhance the bending stiffness of the rotor, the smaller the maximum vibration eccentricity, the smaller the radial electromagnetic force resultant force, the corresponding radial stress reduction effect in the middle part 3 decreases, the radial decomposition of force decreases, and the deflection also decreases accordingly.

[0035] Furthermore, the total length of the first segment 31 along its axial direction is L1, and the total length of the second segment 32 along its axial direction is L2. Then d1, d2, L1 and L2 must satisfy the following conditions: d2≤d1, L2≥L1. At this time, the effects of the first segment 31 and the second segment 32 on the rotor center 3 being close to the main end 1 are superimposed, so that the rotor center of gravity is close to the main end 1. At this time, the effect of reducing eccentricity is optimal, and the eccentric electromagnetic force of the rotor is minimized.

[0036] Furthermore, the values ​​of L1 and L2 can also be adjusted according to the crankshaft structure used. In order to reduce the decrease in magnetic flux density and ensure rotor efficiency, L1 and L2 must also meet the following conditions:

[0037] In some embodiments, the radial distance between the first step portion 31 and the second step portion 32 is L3, the outer diameter of the first step portion 31 is φ1, and the outer diameter of the second step portion 32 is φ2. Then, L3, φ1, and φ2 must satisfy the following conditions:

[0038] It should be noted that the outer diameter φ1 of the first step section 31 and the outer diameter φ2 of the second step section 32 can be adjusted according to actual production needs. It should also be considered that the air gap between the stator and the rotor should not be too small, whether there are other step sections, and the size of the outer diameter of the step sections, etc. The specific settings are determined by the air gap requirements between the stator and the rotor and the design requirements of the compressor.

[0039] In this embodiment, the rotor includes a rotor core 10, which includes a plurality of rotor laminations with different outer diameters stacked along the axial direction.

[0040] It should be noted that the rotor core 10 is composed of rotor laminations of different outer diameters stacked and pressed together, and finally fastened and cast after being fixed by snap-fit ​​connection. The material (e.g., rotor silicon steel or rotor guide bar) and shape of the rotor core 10 are not limited, and vary according to the actual operating power requirements and actual production needs of the compressor.

[0041] Examples of motors

[0042] Based on the foregoing embodiments, this embodiment provides an electric motor, including the rotor and a stator, wherein the rotor is rotatably connected to the inner circumference of the stator, or the rotor is rotatably connected to the outer circumference of the stator.

[0043] Preferably, in order to correspond to the rotor of the aforementioned embodiment, the stator in this embodiment is located on the outer periphery of the rotor. By reducing the diameter of the main end 1 and the secondary end 1 of the rotor, the air gap between the stator and the rotor is increased accordingly, thereby reducing the first-order inertial force of the rotor caused by the static eccentricity of the rotor and the stator, and further reducing the electromagnetic noise during startup and the noise and vibration during actual operation.

[0044] Examples of compressors

[0045] Based on the foregoing embodiments, this embodiment provides a compressor, including the aforementioned motor. Additionally, the compressor also includes a piston, etc. A compressor is a driven fluid machine that elevates low-pressure gas to high-pressure gas; it is the heart of a refrigeration system. It draws in low-temperature, low-pressure refrigerant gas through the suction pipe, compresses it using the piston driven by the motor, and then discharges high-temperature, high-pressure refrigerant gas through the exhaust pipe, providing power for the refrigeration cycle and thus realizing the refrigeration cycle of compression → condensation (heat release) → expansion → evaporation (heat absorption).

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0047] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A rotor, characterized in that, include: The rotor consists of a main end, a middle section, and a secondary end, which are distributed sequentially along the axial direction. The section between the secondary end and the middle section is the first rotor segment, and the section between the main end and the middle section is the second rotor segment. The outer diameter of the first rotor segment gradually decreases from the middle section in a direction away from the second rotor segment, and the outer diameter of the second rotor segment gradually decreases from the middle section in a direction away from the first rotor segment. The first inclination angle of the outer peripheral surface of the first rotor segment relative to the outer peripheral surface of the middle part is α1, and the second inclination angle of the outer peripheral surface of the second rotor segment relative to the outer peripheral surface of the middle part is α2. α1 and α2 satisfy the following condition: 2≥K=α1 / α2>1, and the main end is lower than the secondary end. The outer circumference of the rotor is stepped, and the outer circumference of the rotor includes: The first segment; and The second segment, the orthographic projection of the second segment along the axial direction covers the orthographic projection of the first segment along the axial direction; Wherein, the total axial length of the rotor is L, the distance between the centerline of the first step section and the end face of the main end is d1, and the distance between the centerline of the second step section and the end face of the main end is d2. Then, L, d1, and d2 must satisfy the following conditions: 。 2. The rotor according to claim 1, characterized in that, The rotor also includes a plurality of rotor skew slots arranged along the circumferential direction. The angle of the rotor skew slots is β. Then β, α1 and α2 satisfy the following conditions: α1 < β, α2 < β.

3. The rotor according to claim 1, characterized in that, If the total length of the first segment along its axial direction is L1, and the total length of the second segment along its axial direction is L2, then d1, d2, L1, and L2 must satisfy the following conditions: 。 4. The rotor according to claim 3, characterized in that, L1 and L2 must also meet the following conditions: 。 5. The rotor according to claim 1, characterized in that, The rotor includes a rotor core, which comprises a plurality of rotor laminations with different outer diameters stacked axially.

6. The rotor according to claim 2, characterized in that, The rotor slot is any one of an open slot, a closed slot, a semi-open slot, and a semi-closed slot.

7. An electric motor, characterized in that, include: The rotor according to any one of claims 1-6.

8. A compressor, characterized in that, Includes the motor described in claim 7.

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