WO2020134509A1

WO2020134509A1 - Motor rotor, compressor and air conditioning device

Info

Publication number: WO2020134509A1
Application number: PCT/CN2019/113949
Authority: WO
Inventors: 刘华; 张治平; 叶文腾; 李宏波; 陈玉辉; 钟瑞兴; 亓静利
Original assignee: 珠海格力电器股份有限公司
Priority date: 2018-12-25
Filing date: 2019-10-29
Publication date: 2020-07-02
Also published as: CN111371211A

Abstract

A motor rotor that has an increased critical speed, a compressor and an air conditioning device, the motor rotor comprising: a magnetic portion (1) which is used for rotating under the action of an energized coil; and a shaft body (2) which is connected to the magnetic portion (1) and which extends along the axial direction of the motor rotor away from the magnetic portion (1), wherein the shaft body (2) is provided thereon with a cavity (3) that extends along the axial direction thereof.

Description

Motor rotors, compressors and air conditioning equipment

This disclosure is based on the application with CN application number CN201811593278.9 and the application date is December 25, 2018, and claims its priority. The disclosure content of this CN application is hereby incorporated into the present disclosure as a whole.

Technical field

The present disclosure relates to the field of refrigeration equipment, and in particular, to a motor rotor, compressor, and air conditioning equipment.

Background technique

Centrifugal refrigeration compressors are high-speed compressors. The compressor rotor rotates at high speed during operation, and reliable bearings are needed to support the rotor. The bearings used in conventional rotors mainly include rolling bearings, oil film bearings and magnetic suspension bearings. For rolling bearings and oil film bearings, the compressor requires an additional oil lubrication system and a complicated oil supply oil circuit system. At the same time, the refrigerant and the lubricant are compatible, and a separation system needs to be added to the system, which will cause the entire system to be too complicated and huge.

Due to the high bearing capacity of rolling bearings and oil film bearings, the rotors of motors used in conventional centrifugal compressors are of an integrated structure. The weight of the compressor rotor of this structure is relatively heavy, which is not conducive to the improvement of the rotor's critical speed. When the larger rotor is manufactured by the integrated structure, the processing process is relatively complicated, and the equipment requirements are relatively high, which will increase the cost.

Therefore, in order to solve the complicated oil circuit system of the compressor, oil-free and environmentally friendly magnetic suspension bearings have appeared. For the magnetic levitation bearing, the oil supply system and the separation system are omitted, but a more complicated control system is added. Since the magnetic levitation bearing needs a stable power supply, in order to prevent the system from being suddenly powered off, a protection system needs to be added, which leads to the entire compressor maintenance cost Increased, the structure is more complicated.

In order to solve the problem of the critical speed of the rotor of the compressor, the existing compressor mainly increases the critical speed of the rotor by reducing the length of the rotor or increasing the rigidity of the bearing. However, reducing the length of the rotor is affected by the size of each component, and the degree of optimization can be relatively small. Improving the bearing stiffness, the need to increase the bearing volume at high speeds will cause the compressor to become larger overall, violating the development trend of miniaturization.

Public content

The present disclosure aims to provide a motor rotor, a compressor, and an air-conditioning device to improve the problem of low critical rotation speed of the related art motor rotor due to heavy weight.

According to an aspect of an embodiment of the present disclosure, the present disclosure provides a motor rotor of a compressor, the motor rotor including:

Magnetic part for rotation under the action of energized coil; and

The shaft body is connected to the magnetic part and extends in a direction away from the magnetic part along the axial direction of the motor rotor. The shaft body is provided with a cavity extending along the axial direction.

In some embodiments,

The cavity extends from the end of the shaft body away from the magnetic portion to the end of the shaft body adjacent to the magnetic portion; or

The cavity extends from the end of the shaft body away from the magnetic portion toward the magnetic portion and is spaced from the end of the shaft body adjacent to the magnetic portion; or

The cavity includes a first cavity and a second cavity spaced apart from the first cavity.

In some embodiments, the first cavity extends from the end of the shaft body away from the magnetic portion toward the other end of the shaft body, and the second cavity extends from the end of the shaft body adjacent to the magnetic portion toward the other end.

In some embodiments, the shaft body includes a first shaft body provided at a first end of the magnetic portion along the axial direction of the motor rotor, the motor rotor further includes a sleeve connected to the first shaft body, and the magnetic portion is sleeved on the sleeve Inside the tube.

In some embodiments, the motor rotor further includes a first flow channel for exhausting gas in the sleeve when the magnetic portion is sleeved in the sleeve.

In some embodiments, the first flow channel includes:

A cavity provided on the first shaft body; and/or

The first hole provided on the magnetic part extends from one end of the magnetic part along the axial direction of the motor rotor to the other end.

In some embodiments, the first flow path includes a cavity provided on the first shaft body, the cavity is spaced from the inner cavity of the sleeve, and the first flow path further includes an inner cavity provided on the first shaft body and communicating with the sleeve And the second channel of the cavity.

In some embodiments, the shaft body further includes a second shaft body disposed at a second end of the magnetic portion along the axial direction of the motor rotor, and the second shaft body is at least partially sleeved in the sleeve.

In some embodiments, the motor rotor further includes a second flow passage for exhausting the gas in the sleeve when the second shaft body is sleeved in the sleeve.

In some embodiments, the second flow channel includes:

A cavity provided on the second shaft body; and/or

A first hole provided on the magnetic part and a cavity provided on the first shaft body.

In some embodiments,

The first shaft body is integrally formed with the sleeve; or

The first shaft body is at least partially sleeved in the sleeve.

According to another aspect of the present disclosure, there is also provided a compressor including the above-mentioned motor rotor.

In some embodiments, the compressor further includes:

Centrifugal impeller connected to the end of the shaft body away from the magnetic part; and

The diffuser is used to compress the refrigerant accelerated by the centrifugal impeller.

In some embodiments, the compressor further includes an air suspension bearing for carrying the rotor of the motor.

According to another aspect of the present disclosure, there is also provided an air conditioner including the compressor described above.

Applying the technical solution of the present disclosure, the shaft body of the motor rotor is provided with a cavity, which improves the problem of low critical speed caused by the heavy weight of the motor rotor in the related art.

BRIEF DESCRIPTION

The drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The exemplary embodiments and descriptions of the present disclosure are used to explain the present disclosure, and do not constitute an undue limitation on the present disclosure. In the drawings:

FIG. 1 shows a schematic structural diagram of a compressor motor rotor of an embodiment of the present disclosure;

2 shows a schematic structural diagram of a compressor motor rotor according to an alternative embodiment of the present disclosure;

3 shows an exploded view of a compressor motor rotor of another alternative embodiment of the present disclosure; and

FIG. 4 shows a schematic structural diagram of a compressor of an embodiment of the present disclosure.

In the picture:

1. Magnetic part; 2. Shaft body; 3. Cavity; 4. Sleeve; 5. First hole; 6. Second hole; 7. Mandrel; 8. Centrifugal impeller; 9. Diffuser; 10. Volute; 11, bearing support; 12, bearing.

detailed description

In order to make the purpose, technical solutions and advantages of the disclosure more clear, the disclosure will be further described in detail in conjunction with the embodiments and the drawings. Here, the exemplary embodiments of the present disclosure and the description thereof are used to explain the present disclosure, but are not intended to limit the present disclosure.

FIG. 1 shows a schematic structural diagram of a motor rotor of the compressor of this embodiment. As shown in FIG. 1, in this embodiment, the motor rotor of the compressor includes a magnetic portion 1 for rotating under the action of an energized coil, and a shaft connected to the magnetic portion 1 and extending away from the magnetic portion 1 along the axial direction of the motor rotor The body 2 is provided with a cavity 3 extending along its axial direction.

The motor rotor of the compressor of this embodiment is provided with a cavity 3 extending along its axial direction, the weight of the electronic rotor is reduced, which is beneficial to increase the maximum speed of the motor rotor.

In this embodiment, the cavity 3 extends from the end of the shaft body 2 away from the magnetic portion 1 to the end of the shaft body 2 adjacent to the magnetic portion 1.

As shown in FIG. 2, in another embodiment, the cavity includes a first cavity 3 a and a second cavity 3 b spaced apart from the first cavity 3 a. A solid shaft body is formed between the first cavity 3a and the second cavity 3b, and the solid shaft body plays a supporting role, which is beneficial to improve the structural strength of the motor rotor.

As shown in FIG. 3, in another embodiment, the cavity 3 extends from the end of the shaft 2 away from the magnetic portion 1 toward the magnetic portion 1, and is spaced from the end of the shaft 2 adjacent to the magnetic portion 1, the cavity Between 3 and the magnetic part 1 is a solid shaft.

The shaft body 2 includes a first shaft body 2a provided at the first end of the magnetic portion 1 along the axial direction of the motor rotor. The motor rotor further includes a sleeve 4 connected to the first shaft body 2a. The magnetic portion 1 is sleeved on the sleeve Inside the tube 4.

In this embodiment, the sleeve 4 is integrally formed with the first shaft body 2a in this embodiment. In other optional embodiments, the first shaft body 2a is partially or completely sleeved in the sleeve 4.

The shaft body 2 further includes a second shaft body 2b provided at the second end of the magnetic portion 1 along the axial direction of the motor rotor. The second shaft body 2b is at least partially sleeved in the sleeve 4.

The motor rotor further includes a first flow path for discharging the gas in the sleeve 4 when the magnetic portion 1 is sleeved in the sleeve 4.

The first flow path includes a cavity 3 provided on the first shaft body 2a. The cavity 3 on the first shaft body 2a extends from one end of the first shaft body 2a adjacent to the magnetic portion 1 to the other end. In the process of thermally sheathing the magnetic part 1 in the sleeve 4, the gas in the sleeve 4 is discharged through the cavity 3 on the first shaft body 2 a.

In some embodiments, the cavity 3 on the first shaft body 2a extends from one end of the first shaft body 2a adjacent to the magnetic portion 1 toward the other end, and the first shaft body 2a is further provided with a cavity for communicating with the shaft body 3 The through hole in the outer space of 2 extends in the radial direction of the shaft body 2 in some embodiments. The cavity 3 described above does not need to extend to the end of the first shaft body 2a adjacent to the magnetic portion 1. During the process of thermally sheathing the magnetic portion 1 in the sleeve 4, the gas in the sleeve 4 passes through the first shaft body 2 a The upper cavity 3 and the above-mentioned through hole are discharged.

The motor rotor further includes a second flow path for discharging the gas in the sleeve 4 when the second shaft body 2b is sleeved in the sleeve 4.

The second flow path includes a cavity 3 provided on the second shaft body 2b. The cavity 3 on the second shaft body 2b extends from one end of the second shaft body 2b adjacent to the magnetic portion 1 toward the other end. In the process of thermally sheathing the second shaft body 2b in the sleeve 4, the gas in the sleeve 4 is discharged through the cavity 3 provided on the second shaft body 2b.

In some embodiments, the cavity 3 extends from one end adjacent to the magnetic portion 1 toward the other end, and the second shaft body 2 b is further provided with a through hole communicating with the external space of the shaft body 2 of the cavity 3. In some embodiments, the through hole extends in the radial direction of the second shaft body 2. In the process of thermally sheathing the second shaft body 2b in the sleeve 4, the gas in the sleeve 4 is discharged through the cavity 3 and the through hole provided in the second shaft body 2b.

In some embodiments, the cavity 3 extends from the end of the second shaft body 2b away from the magnetic portion 1 toward the magnetic portion 1, the cavity 3 is spaced from the magnetic portion 1, the cavity 3 and the solid shaft body of the magnetic portion 1 With exhaust vents.

FIG. 2 shows a schematic structural diagram of a motor rotor of another alternative embodiment. The motor rotor of this embodiment includes a first flow channel for exhausting gas in the sleeve 4 when the magnetic portion 1 is thermally sleeved in the sleeve 4 The first flow channel includes a first hole 5 provided on the magnetic part 1, and the first hole 5 extends from one end of the magnetic part 1 along the axial direction of the motor rotor to the other end. In the process of thermally sheathing the magnetic part 1 into the sleeve 4, the gas in the sleeve 4 can be discharged through the first hole 5 in the magnetic part 1.

As shown in FIG. 2, the cavity 3 provided on the first shaft body 2a includes a first cavity 3a and a second cavity 3b spaced apart from the first cavity 3a.

The rotor of the motor further includes a second flow channel for discharging the gas in the sleeve 4 during the process of sleeve-fitting the second shaft body 2b into the sleeve 4, the second flow channel includes a cavity 3 provided on the second shaft body 2b The cavity 3 extends from one end of the second shaft body 2b adjacent to the magnetic portion 1 to the other end.

In some embodiments, the second shaft body 2b is provided with a through hole for communicating the cavity 3 and the external space of the shaft body 2. The cavity 3 on the second shaft body 2b extends from one end adjacent to the magnetic portion 1 toward the other end, and the cavity 3 need not extend to the end of the second shaft body 2b away from the magnetic portion 1.

FIG. 3 shows a schematic structural view of a motor rotor of another alternative embodiment. The motor rotor of this embodiment includes a first flow channel for exhausting gas in the sleeve 4 when the magnetic part 1 is thermally sleeved into the sleeve 4, The first flow channel includes a cavity 3 provided on the first shaft body 2a and a second hole 6 for communicating the cavity 3 and the inner cavity of the sleeve 4.

In this embodiment, the cavity 3 on the first shaft body 2a extends from the end of the first shaft body 2a away from the magnetic portion 1 toward the magnetic portion 1. The cavity 3 is spaced from the inner cavity of the sleeve 4, and the cavity 3 and The solid shaft body between the inner cavities of the sleeve 4 is provided with a second hole 6, and two ends of the second hole 6 communicate with the cavity 3 and the inner cavity of the sleeve 4 respectively.

In the process of fitting the magnetic part 1 into the sleeve 4, the gas in the sleeve 4 is discharged through the second hole 6 and the cavity 3 provided on the first shaft body 2a.

In some embodiments, the second flow path for exhausting gas when the second shaft body 2b is sleeved into the sleeve 4 includes a first hole provided on the magnetic portion 1 and a hollow provided on the first shaft body 2a Cavity 3.

According to another aspect of the present disclosure, a compressor is also provided. FIG. 4 shows a schematic structural diagram of the compressor of this embodiment. As shown in FIG. 4, the compressor of this embodiment includes a motor rotor. The motor rotor includes a magnetic portion 1 and a shaft body 2 connected to the magnetic portion 1.

The compressor also includes a centrifugal compression section driven by a motor rotor. The centrifugal compression section includes a centrifugal impeller 8 connected to the end of the motor rotor, a diffuser 9 for compressing the refrigerant accelerated by the centrifugal impeller therein, and a volute 10 that discharges the compressed refrigerant.

As shown in FIG. 4, the compressor further includes a mandrel 7. The first end of the mandrel 7 is inserted into the cavity on the shaft body 2 and connected to the solid shaft body section of the shaft body 2. The centrifugal impeller 8 is fixed on the mandrel 7 The second end.

The centrifugal compression section includes a first centrifugal compression section provided at the first end of the motor rotor and a second centrifugal compression section provided at the second end of the motor rotor. The suction port of the second centrifugal compression part communicates with the exhaust port of the first centrifugal compression part, and the second centrifugal compression part is used to compress the refrigerant compressed by the first centrifugal compression part.

The compressor also includes a bearing support 11 and a bearing 12 mounted on the bearing support 11, the bearing 12 being used to carry the motor rotor. The bearing 12 is an air suspension bearing. Preferably, the air suspension bearing is a dynamic pressure air suspension bearing.

With reference to FIGS. 1 to 4, the compressor rotor of this embodiment is mainly composed of three sections of a first shaft body 2a, a magnetic portion 1 and a second shaft body 2b, wherein the middle section is the magnetic portion 1, the first shaft body 2a and the second shaft body 2b are provided with a cavity 3 extending axially. The overall quality of the motor rotor is reduced, thereby increasing the rotor's critical speed and increasing the bearing capacity of the bearing.

The compressor of this embodiment is a two-stage dynamic pressure air suspension centrifugal compressor. The compressor includes a first compression section, a second compression section for compressing the refrigerant compressed by the first compression section, a motor for driving the first compression section and the second compression section, and a circulating air supply self-cooling system. The circulating air supply self-cooling system provides the bearing 12 in the compressor cavity with a cooling medium for cooling and/or lubrication.

The motor rotor system of the compressor mainly includes a centrifugal impeller 8 in the first compression part, a hollow first shaft body 2a, a magnetic part 1, a hollow second shaft body 2b, a centrifugal impeller 8 in the second compression part, and a thrust bearing thrust body. The shaft body 2 of the motor rotor of the compressor includes a hollow structure and a solid structure. The motor rotor of this structure type can be applied to rotating machinery such as centrifugal refrigeration compressors and screw refrigeration compressors.

The bearings involved in the solution may be sliding bearings, rolling bearings, magnetic suspension bearings or air suspension bearings. Considering the simple structure of oil-free and environmental protection, air suspension bearings are preferred.

The structure diagram of the new three-segment hollow high-speed rotor is shown in Figure 2. The motor rotor is mainly composed of the first shaft body 2a, the magnetic part 1 and the second shaft body 2b. The left and right shaft bodies 2 are processed into a hollow structure, and the middle is The integral magnetic part 1 omits the middle mandrel, which is beneficial to simplify the structure and reduce assembly. The first shaft body 2a at the left end is processed into a two-section hollow structure, the left end is a cooling gas channel, and the right end is a hollow sleeve equipped with a magnetic part 1. Or the second shaft body 2b on the right end is processed into a structure similar to the first shaft body 2a; the solid part of the first shaft body 2a on the left end can be disposed away from the magnetic portion 1, and the first hole 5 is processed in the center of the magnetic portion 1, the first A hole can be a light hole or a threaded hole. The number of the first holes 5 is reasonably arranged according to the spatial structure. Similarly, the second shaft body 2b at the right end may use the same structure as the first shaft body 2a. The hollow structure of the first shaft body 2a and the second shaft body 2b at the left and right ends can also be processed with a full hole or a small hole or threaded hole structure in the solid part, but the diameter of the hole needs to be strictly controlled to prevent the shaft and the magnetic part 1 Is too small to damage the magnetic part 1, that is, D hole ≤ (1/2) D magnetic part 1. The volume of the cavity 3 of the two-stage shaft body 2 is kept the same or different from the volume of the sleeve section, or the solid section of the shaft body 2 is adjusted so that the center of gravity of the motor rotor is close to the center of the overall rotor.

The rotor of the motor is processed separately, and the first shaft body 2a, the second shaft body 2b and the magnetic part 1 are processed separately, which can effectively ensure the required key size, simplify the processing complexity, facilitate the rotor inspection, and improve the inspection accuracy . The two-stage shaft body 2 and the center of the magnetic part 1 can be processed with small holes, but the size of the small holes cannot be too large due to the influence of the material of the magnetic part 1. Generally, φD3≤4mm is suitable. Due to the fact that there is no gas in the rotor of the motor rotor during the heat jacket process, it is necessary to add a small hole to exhaust the solid part of the first shaft body 2a or the second shaft body 2b, and the hole diameter is 2 to 3 mm.

Through the above structure, not only the bearing capacity problem is effectively solved, but also the critical rotation speed of the rotor is increased by reducing the length of the cantilever end, and the working stability and reliability of the motor are further improved.

The present disclosure uses dynamic pressure air suspension bearings, which not only eliminates the need for the compressor to use lubricating oil and control systems, but also makes the compressor more environmentally friendly and has a simpler structure; at the same time, it also solves the difficult problem of integrated inspection of the compressor rotor and effectively improves the rotor The critical rotation speed ensures the reliability and safety of the shafting and reduces the maintenance cost of the compressor. The above is only the preferred embodiments of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the embodiments of the present disclosure may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of this disclosure shall be included in the protection scope of this disclosure.

Claims

A motor rotor, including:

The magnetic part (1) is used to rotate under the action of the energized coil; and

A shaft body (2) is connected to the magnetic part (1) and extends in a direction away from the magnetic part (1) along the axial direction of the motor rotor. The shaft body (2) is provided with a shaft Toward the cavity (3).
The motor rotor according to claim 1, wherein

The cavity (3) extends from an end of the shaft body (2) away from the magnetic portion (1) to an end of the shaft body (2) adjacent to the magnetic portion (1); or

The cavity (3) extends from the end of the shaft body (2) away from the magnetic portion (1) toward the magnetic portion (1) and is adjacent to the magnetic body of the shaft body (2) At one end of part (1); or

The cavity (3) includes a first cavity (3a) and a second cavity (3b) spaced apart from the first cavity (3a).
The motor rotor according to claim 2, wherein the first cavity (3a) is directed from an end of the shaft body (2) away from the magnetic portion (1) toward an end adjacent to the magnetic portion (1) The second cavity (3b) extends from an end of the shaft body (2) adjacent to the magnetic portion (1) toward an end away from the magnetic portion (1).
The motor rotor according to any one of claims 1 to 3, wherein the shaft body (2) includes a first provided at a first end of the magnetic portion (1) along the axial direction of the motor rotor A shaft body (2a), the motor rotor further includes a sleeve (4) connected to the first shaft body (2a), and the magnetic portion (1) is sleeved in the sleeve (4).
The motor rotor according to claim 4, further comprising a first flow path for discharging the gas in the sleeve (4) when the magnetic portion (1) is fitted in the sleeve (4).
The motor rotor according to claim 5, wherein the first flow path includes:

The cavity (3) provided on the first shaft body (2a); or

A first hole (5) provided in the magnetic part (1) extends from one end of the magnetic part (1) along the axial direction of the motor rotor to the other end.
The motor rotor according to claim 5, wherein the first flow path includes a cavity (3) provided on the first shaft body (2a), the cavity (3) and the sleeve (4 ), the first flow channel further includes a second hole (6) provided on the first shaft body (2a) and communicating the inner cavity of the sleeve and the cavity (3).
The motor rotor according to claim 4, wherein the shaft body (2) further includes a second shaft body (2b) provided at a second end of the magnetic portion (1) along the axial direction of the motor rotor, so The second shaft body (2b) is at least partially sleeved in the sleeve (4).
The motor rotor according to claim 8, further comprising a second flow for exhausting the gas in the sleeve (4) when the second shaft body (2b) is sleeved in the sleeve (4) Road.
The motor rotor according to claim 9, wherein the second flow path includes:

The cavity provided on the second shaft body (2b); or

A first hole (5) provided on the magnetic part (1) and a cavity (3) provided on the first shaft body (2a).
The motor rotor according to claim 4, wherein:

The first shaft body (2a) and the sleeve (4) are integrally formed; or

The first shaft body (2a) is at least partially sleeved in the sleeve (4).
A compressor comprising the motor rotor according to any one of claims 1 to 11.
The compressor of claim 12, wherein the compressor further comprises:

A centrifugal impeller (8) connected to the end of the shaft body (2) away from the magnetic part (1); and

A diffuser (9) is used for compressing the refrigerant accelerated by the centrifugal impeller (8) therein.
The compressor according to claim 12 or 13, further comprising an air suspension bearing for carrying the rotor of the motor.
An air-conditioning apparatus including the compressor according to any one of claims 12 to 14.