WO2023273193A1

WO2023273193A1 - Compressor and electric motor thereof

Info

Publication number: WO2023273193A1
Application number: PCT/CN2021/137875
Authority: WO
Inventors: 俞国新; 常云雪; 朱万朋; 李思茹; 韩聪
Original assignee: 青岛海尔智能技术研发有限公司; 海尔智家股份有限公司
Priority date: 2021-06-30
Filing date: 2021-12-14
Publication date: 2023-01-05
Also published as: CN115566830A

Abstract

A compressor and an electric motor thereof. The electric motor comprises a stator and a rotor. The rotor is rotatably arranged on an inner side of the stator and comprises a main shaft and a permanent magnet fixed on the main shaft in a sleeved manner, wherein a central flow channel extending in an axial direction of the main shaft is arranged in the main shaft; a plurality of flow diffusion holes and at least one flow inlet, which are in communication with the central flow channel, are inwardly provided in a peripheral surface of the main shaft; the main shaft is sleeved with a cross-flow ring at the position of the flow inlet; and the cross-flow ring is provided with a plurality of cross-flow suction ports, so as to suck a liquid cooling medium into the flow inlet when the cross-flow ring rotates along with the main shaft, such that the cooling medium flows in the central flow channel to cool the rotor, and is then thrown out of the main shaft by means of the plurality of flow diffusion holes. On the basis of the solution in the present invention, the rotor can be sufficiently cooled, and the flowing power of a cooling medium in the central flow channel can be increased.

Description

Compressor and its motor

technical field

The invention relates to the technical field of compressors, in particular to a compressor and a motor thereof.

Background technique

Permanent magnet synchronous motors are widely used in the field of compressors, especially refrigeration compressors such as centrifugal compressors and screw compressors. High-speed permanent magnet synchronous motors mostly use surface-mounted permanent magnets. The permanent magnets are attached to the rotor shaft to form the rotor, and then the metal or carbon fiber sheath is used to fix its position.

However, the high rotational speed of permanent magnet synchronous motors for compressors results in large eddy current losses and wind friction losses of permanent magnets or metal sheaths, especially for refrigeration compressors. The existing technology mainly uses the cooling medium to flow naturally in the air gap between the stator and the rotor or uses water to cool the motor casing to cool the motor, which has a certain cooling effect on the stator, but the high speed of the rotor causes the cooling medium to High flow resistance, coupled with low thermal conductivity of the gaseous cooling medium and other unfavorable factors, lead to poor cooling effect of the motor rotor, affecting the high-speed operation efficiency and reliability of the motor.

Contents of the invention

An object of the present invention is to solve, or at least partly solve, the above-mentioned problems of the prior art by providing a compressor motor capable of applying good cooling to the rotor.

A further object of the present invention is to increase the flow power of the cooling medium in the central channel.

Another object of the present invention is to provide a compressor having the above motor.

In one aspect, the present invention provides a motor for a compressor, which includes:

stator; and

The rotor is rotatably arranged inside the stator, including a main shaft and a permanent magnet sleeved on it. A central flow channel extending along the axial direction is opened inside the main shaft, and a communication channel is opened on the outer peripheral surface of the main shaft. A plurality of diffusion holes and at least one inflow port of the central channel, the main shaft is sleeved with a through-flow ring at the position of the inflow port;

The through-flow ring is provided with a plurality of through-flow suction ports, so that when the through-flow ring rotates with the main shaft, the liquid cooling medium is sucked into the inlet, so that the cooling medium flows in the central channel to The rotor is cooled, and then thrown out of the main shaft by the plurality of diffuser holes.

Optionally, in the direction from the inner periphery to the outer periphery of the through-flow ring, each of the through-flow suction ports gradually extends obliquely toward the rotation direction of the through-flow ring.

Optionally, in the direction of rotation of the through-flow ring, the front wall of each of the through-flow suction ports facing forward is in the shape of a broken line that is convex in the middle, and the rear wall facing backward is in the shape of a straight line or a concave curved shape.

Optionally, in the direction from the inner periphery to the outer periphery of the through-flow ring, the width of each through-flow suction port first decreases and then increases.

Optionally, each of the inlets is fan-shaped coaxially with the main axis.

Optionally, the plurality of through-flow suction ports are evenly distributed along the circumference of the through-flow ring.

Optionally, the at least one inflow port and the plurality of diffusion holes are located on a section of the main shaft not covered by the permanent magnet, and are respectively located on both sides of the permanent magnet;

The main shaft is fixedly sleeved with a stop ring at the position of the diffuse flow hole, and the stop ring is provided with liquid outlet holes corresponding to the plurality of diffuse flow holes one by one;

The permanent magnet is sandwiched by the through-flow ring and the stop ring so that its axial displacement is constrained.

Optionally, the inner wall of the central channel is provided with a spiral groove coaxial with the main shaft, so that when the rotor rotates, the cooling medium at the inlet is driven toward the direction of the plurality of diffuser holes flow.

Optionally, the motor further includes a casing, the casing seals the stator and the rotor inside, and the main shaft protrudes through the opening at the end of the casing to connect to the compression part;

A liquid inlet for introducing the cooling medium and a discharge port for discharging the cooling medium are opened on the housing; and

The liquid inlet is used to connect to a throttling device of the refrigeration system, the cooling medium flowing into the liquid inlet is throttled refrigerant, and the outlet is used to communicate with the evaporator of the refrigeration system.

In another aspect, the present invention also provides a compressor, which includes the motor described in any one of the above items.

In the motor of the compressor of the present invention, the main shaft of the rotor is provided with a central channel and a plurality of diffuser holes. After the cooling medium enters the central flow channel, it cools the main shaft and the permanent magnets directly connected to the main shaft during the flow along the central flow channel, realizing the cooling of the motor rotor, making the motor more efficient and more reliable. During the rotation of the main shaft, the high-temperature cooling medium in the central flow channel that has cooled the main shaft is thrown out of the main shaft by centrifugal action through multiple diffuser holes, so as to allow new cooling medium to continuously enter the central flow channel. Therefore, the cooling scheme of the present invention promotes the cooling medium to flow continuously along the axial direction of the main shaft, so that the cooling effect is better. The main shaft is equipped with a through-flow ring at the inlet of the central flow channel. The through-flow ring can suck the liquid cooling medium into the inlet when it rotates with the main shaft, which is equivalent to playing the role of a pump, so that the cooling medium can enter the center with a larger flow rate. Runners to ensure better cooling effect.

Further, the present invention makes a series of special designs on the extension direction, shape, width, etc. of the through-flow suction port of the through-flow ring, so that the liquid absorption capacity of the through-flow suction port is stronger, so that a larger flow of cooling medium enters the central flow channel .

Further, in the motor of the present invention, the inner wall of the central flow channel is provided with a spiral groove coaxial with the main shaft. During the rotation of the main shaft, the spiral groove can drive the cooling medium to flow more forcefully in the central flow channel. In addition, due to the spiral grooves, the surface shape of the inner wall of the central flow channel is more uneven, which is also conducive to sufficient heat exchange with the cooling medium, so that the cooling effect is better.

Further, in the motor of the present invention, the cooling medium is a throttling refrigerant. The temperature of the refrigerant decreases after being throttled, and it is used as a cooling medium to cool the rotor, so that the temperature of the rotor is lowered more.

Those skilled in the art will be more aware of the above and other objects, advantages and features of the present invention according to the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of illustration and not limitation with reference to the accompanying drawings. The same reference numerals in the drawings designate the same or similar parts or parts. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the attached picture:

1 is a schematic cross-sectional view of a motor according to an embodiment of the present invention;

Fig. 2 is a structural schematic diagram of the rotor in the motor shown in Fig. 1;

Fig. 3 is the structural representation of main shaft of the present invention;

Fig. 4 is a schematic diagram of another angle of the main shaft shown in Fig. 3;

Fig. 5 is a schematic structural view of the through-flow ring of the present invention;

Figure 6 is a schematic diagram of the assembly of the main shaft and the through-flow ring;

Fig. 7 is an enlarged cross-sectional view obtained by cutting the structure shown in Fig. 6 along the through-flow ring;

Fig. 8 is a schematic diagram of another perspective of the structure shown in Fig. 7;

Fig. 9 is the structural representation of cooler of the present invention;

Fig. 10 is a schematic diagram of the assembly structure of the stator and the cooler of the present invention;

Fig. 11 is a schematic left view of Fig. 10;

Fig. 12 is an enlarged view of place A of Fig. 11;

Fig. 13 is a schematic diagram of another embodiment of the stator;

Fig. 14 is an enlarged view at B of Fig. 13;

Fig. 15 is a partial schematic diagram of a motor in its thrust bearing according to an embodiment of the present invention.

detailed description

A motor 1 and a compressor according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 15 . In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Axial", "Radial", "Circumferential" ", "clockwise", "counterclockwise" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device Or elements must have a certain orientation, be constructed and operate in a certain orientation, and thus should not be construed as limiting the invention.

The terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless specifically defined otherwise. When a feature "comprises or comprises" one or some of the features it encompasses, unless specifically stated otherwise, this indicates that other features are not excluded and that other features may be further included.

Unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected", "fixed" and "coupled" should be interpreted in a broad sense, for example, it can be a fixed connection or a detachable connection, or a Integral; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. Those of ordinary skill in the art should be able to understand the specific meanings of the above terms in the present invention according to specific situations.

In addition, in the description of this embodiment, the first feature being "on" or "under" the second feature may include that the first and second features are in direct contact, and may also include that the first and second features are not in direct contact but is through additional feature contacts between them. That is to say, in the description of this embodiment, the first feature being "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicating the level of the first feature The height is higher than the second feature. The first feature being "under", "under", or "under" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the level of the first feature is smaller than that of the second feature.

Unless otherwise defined, all terms (including technical terms and scientific terms) used in the description of this embodiment have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs.

Fig. 1 is a schematic sectional view of a motor 1 according to an embodiment of the present invention, Fig. 2 is a schematic structural view of a rotor 30 in the motor 1 shown in Fig. 1, Fig. 3 is a schematic structural view of a main shaft 31 of the present invention, and Fig. 4 is a schematic view of 3 shows a schematic diagram of another angle of the main shaft 31, FIG. 5 is a schematic structural diagram of the through-flow ring of the present invention, and FIG. 6 is a schematic diagram of the assembly of the main shaft and the through-flow ring. In the figure, x represents the axial direction of the motor, stator, rotor and main shaft.

As shown in FIGS. 1 to 3 , the motor 1 for a compressor according to the embodiment of the present invention may generally include a stator 20 and a rotor 30 . The rotor 30 is rotatably placed inside the stator 20 and includes a main shaft 31 and a permanent magnet 32 sleeved thereon. After the stator 20 is energized, a magnetic force is generated between the rotor 30 and the stator to drive the rotor 30 to rotate. Specifically, the stator 20 includes a stator core 21 and a winding 22 , and the stator 20 is generally ring-shaped as a whole. The rotor 30 is coaxially arranged inside the stator 20, and the outer peripheral surface of the rotor 30 has an air gap with the inner peripheral surface of the stator core 21. Outputs torque to the compression section. The permanent magnet 32 can be in the shape of a tile and wraps around the outer periphery of the main shaft 31 . The outer periphery of the permanent magnet 32 is covered with a fixed collar 33 to fix the position of the permanent magnet 32 .

A central channel 310 extending along the axial direction is opened in the main shaft 31 . In other words, the main shaft 31 defines an inner hole. The outer peripheral surface of the main shaft 31 is provided with a plurality of diffusion holes 312 and at least one inflow port 311 communicating with the central flow channel 310, so that when the main shaft 31 rotates, the liquid cooling medium enters it through the inflow port 311 of the central flow channel 310, The rotor 30 is cooled, and then thrown out of the main shaft 31 through a plurality of diffuser holes 312 . Specifically, when the main shaft 31 rotates, the liquid cooling medium has a tendency to move radially outward under centrifugal action, so it can flow out through the diffuser hole 312 . Specifically, the plurality of diffuser holes 312 may be located at the same position in the axial direction of the main shaft 31 and evenly distributed along the circumferential direction of the main shaft 31 . Certainly, a plurality of diffuser holes 312 may also be arranged at different axial positions of the main shaft 31 .

The main shaft 31 is sleeved with a through-flow ring 34 at the position of the inlet 311 . The through-flow ring 34 is provided with a plurality of through-flow suction ports 340, so that when the through-flow ring 34 rotates with the main shaft 31, the liquid cooling medium is sucked into the inflow port 311, so that the cooling medium flows in the central flow channel 310 to cool the rotor 30, and then It is thrown out of the main shaft 31 by a plurality of diffuser holes 312 . A plurality of through-flow suction ports 340 may be evenly distributed along the circumferential direction of the through-flow ring 34 .

In this embodiment, the through-flow ring 34 acts as a pump to promote the cooling medium other than the main shaft 31 to enter the central channel 310 at a greater flow rate, so as to ensure a better cooling effect.

FIG. 7 is an enlarged cross-sectional view obtained by cutting the structure shown in FIG. 6 along the through-flow ring 34 ; FIG. 8 is a schematic diagram of another perspective of the structure shown in FIG. 7 .

In the embodiment of the present invention, a series of special designs are made on the extension direction, shape, and width of the through-flow suction port 340 of the through-flow ring 34, so that the through-flow suction port 340 has a stronger liquid absorption capacity, so that a larger flow of cooling medium enters the center Runner 310. Specifically, as shown in FIGS. 7 and 8 , in the direction from the inner circumference to the outer circumference of the through-flow ring 34 , each through-flow suction port 340 gradually extends obliquely toward the rotation direction of the through-flow ring 34 . Moreover, in the direction from the inner circumference to the outer circumference of the through-flow ring 34 , the width of each through-flow suction port 340 first decreases and then increases. Specifically, in the direction of rotation of the through-flow ring 34 , the front wall 341 of each through-flow suction port 340 facing forward is in the shape of a broken line protruding in the middle, and the rear wall 342 facing backward is in a straight line or a concave curved shape. This shape enables the through-flow ring 34 to absorb more liquid with less leakage.

As shown in Figure 3, Figure 4, Figure 7 and Figure 8, each inlet 311 can be fan-shaped coaxially with the main shaft 31, and the fan-shaped fan can also play a role in guiding the cooling medium toward the central flow channel 310 . The number of fan-shaped inlets 311 may be multiple, such as two, so that they are distributed along the circumferential direction of the main shaft 31 .

As shown in FIG. 1 , the main shaft 31 can be fixedly provided with a retaining ring 35 at the position of the diffuser hole 312 , and the permanent magnet 32 is sandwiched between the through-flow ring 34 and the retaining ring 35 to constrain its axial displacement. The retaining ring 35 is provided with liquid outlet holes 351 opposite to the plurality of diffuser holes 312 to allow the cooling medium to flow out. In the field of the motor 1, in order to cool the motor 1 and dissipate heat in time, a cooling medium is usually introduced, which can be refrigerated oil. For refrigeration compressors, refrigerant can also be used as the cooling medium. However, since the rotor 30 is surrounded by the stator 20, it has less contact with the cooling medium, and the cooling effect is poor. Moreover, the main shaft 31 of the motor 1 generates friction with components such as bearings during rotation, which also generates more heat that is difficult to dissipate. In order to solve this problem, the embodiment of the present invention specially sets the main shaft 31 as a hollow structure, introduces the liquid cooling medium into the main shaft 31 to cool it, so that the cooling effect is better, and creatively uses the diffuser hole 312 to throw out the cooling medium, The cooling medium can continuously flow in the central channel 310 , which can continuously absorb and take away the heat generated by the main shaft 31 , so that the cooling efficiency is higher. In a word, the present invention realizes the cooling of the rotor 30 of the motor 1 by directly cooling the main shaft 31, so that the efficiency of the motor 1 is higher and the reliability is better.

In some embodiments, as shown in FIGS. 1 to 3 , the inlet 311 and the plurality of diffuser holes 312 are located on the section of the main shaft 31 that does not cover the permanent magnet 32 , and are respectively located on both sides of the permanent magnet 32 , so as to Prevent the permanent magnet 32 from blocking the inflow port 311 and the diffuser hole 312 . Specifically, set the first end (a end) of the main shaft 31 as the power output end for connecting with the compression part of the compressor. The central channel 310 is a blind hole formed inwardly from the end surface of the second end (b end) of the main shaft 31. A sealing plug 39 is installed at the opening of the second end of the main shaft 31 in the central channel 310 .

Moreover, the inlet 311 is closer to the power output end than the diffuser hole 312 , and is opened inward from the outer peripheral surface of the main shaft 31 . This structure can prevent the central channel 310 from affecting the inherent structure of the power output end of the main shaft 31 (such as the threaded hole for connecting the impeller) and the structural strength.

In some embodiments, as shown in FIGS. 1 to 3 , the inner wall of the central channel 310 is provided with a helical groove 318 coaxial with the main shaft 31, so that when the rotor 30 rotates, the helical groove 318 drives the flow at the inlet 311. The cooling medium flows in the direction of the plurality of diffuser holes 312 . At this time, the spiral groove 318 acts as a pump, driving the cooling medium to flow more forcefully in the central channel 310 . Due to the helical groove 318, the surface shape of the inner wall of the central channel 310 is more uneven, the contact surface with the cooling medium is larger, the degree of turbulence is higher, and it is also conducive to sufficient heat exchange with the cooling medium, so that the cooling effect is better.

In some embodiments, both the central channel 310 and the diffuser hole 312 can be circular, and the ratio of the diameter of the diffuser hole 312 to the aperture of the central channel 310 is between 0.3˜0.35. The inventors found that this proportional design can make the flow continuity of the cooling medium in the central channel 310 better, and avoid opening larger holes to affect the strength of the main shaft 31 . Further, each diffusion hole 312 can be gradually inclined toward the opposite direction of rotation of the rotor 30 from the inside to the outside, so as to facilitate throwing out the cooling medium.

In some embodiments, as shown in FIG. 1 , the motor 1 further includes a housing 10 . The casing 10 seals the stator 20 and the rotor 30 inside, and the main shaft 31 protrudes through the opening at the end of the casing 10 to connect with the compression part of the compressor. That is, the compressor has a non-contact structure, the motor 1 is independently disposed in the casing 10 , and the main shaft 31 protrudes to connect the compression part located outside the motor 1 . The casing 10 is provided with a liquid inlet 11 for introducing a cooling medium and a discharge port 12 for discharging the cooling medium. The lower temperature cooling medium enters the casing 10 from the liquid inlet 11 , cools the stator 20 and the rotor 30 , the temperature rises, and then discharges from the outlet 12 to take away the heat generated by the motor 1 .

The refrigeration compressor is applied to the vapor compression refrigeration cycle system (which may be referred to as "refrigeration system"). The cycle system is mainly composed of a compressor, a condenser, a throttling device 80 and an evaporator 90 connected by pipelines to form a cycle loop. Refrigerant circulates inside. In the embodiment of the present invention, the liquid inlet 11 is preferably connected to the throttling device 80 of the refrigeration system, the cooling medium flowing into the liquid inlet 11 is the throttled refrigerant, and the outlet 12 is connected to the evaporator 90 of the refrigeration system. In the refrigeration cycle system, the temperature of the refrigerant throttled by the throttling device 80 is the lowest, and it is introduced into the housing 10 of the motor 1 to cool the stator 20 and the rotor 30, so that the cooling range of the stator 20 and the rotor 30 is greater , the cooling force is greater.

As shown in FIG. 1 , the motor 1 also includes two radial bearings 40 . The two ends of the main shaft 31 can be provided with sealing rings, so as to seal between the openings at the two axial ends of the housing 10.

As shown in FIGS. 1 to 4 , in some embodiments, a thrust plate 315 is formed on the main shaft 31 . The electric machine 1 also includes a thrust bearing 50 . The thrust bearing 50 cooperates with the thrust plate 315 to balance the axial external force of the rotor 30 . Specifically, some sections of the main shaft 31 extend radially outwards to form a disc-shaped structure with a diameter larger than that of the surrounding sections to form a thrust plate 315. There are plane thrust surfaces on both axial sides of the thrust plate, and the thrust bearing 50 constrains two thrust plates. surface, so that the main shaft 31 cannot move in the axial direction.

During the operation of the motor 1 , the cooperation between the thrust bearing 50 and the thrust plate 315 will also generate relatively large heat. For this reason, in the embodiment of the present invention, at least one thrust surface of the thrust plate 315 (the two axial planes of the thrust plate are used to bear the axial force, called the thrust surface) is provided with a plurality of guide grooves 3150 (Fig. 3. The shaded part in FIG. 4 marks the diversion groove 3150), so as to drive the liquid cooling medium at the thrust surface to flow and throw it out when the main shaft 31 rotates. The cooling medium completes the cooling of the thrust plate 315 during the flowing process, and then reduces the overall temperature of the rotor 30 , so that the motor 1 has higher efficiency and better reliability. In addition, due to the opening of the diversion groove 3150, the surface of the thrust surface is more uneven, the contact surface with the cooling medium is larger, the degree of turbulence is higher, and the heat exchange effect is better.

Preferably, the two thrust surfaces of the thrust plate 315 are formed with a plurality of guide grooves 3150, so that both sides thereof can be cooled better. The guide grooves 3150 on each thrust surface are evenly distributed in the circumferential direction of the thrust plate 315, so that the cooling of the thrust plate 315 is more uniform. As shown in Figures 3 and 4, each diversion groove 3150 can be extended outward from the inner periphery of the thrust surface to the outer periphery of the thrust surface, so that the coverage in the radial direction is larger, and it is also beneficial to throw out the thrust surface in time. Cooling medium on the push surface. In addition, the width of each diversion groove 3150 increases gradually in the extending direction from the inner peripheral edge to the outer peripheral edge of the thrust surface, so as to accelerate the flow velocity of the cooling medium. Specifically, the two

side walls

3151 and 3152 in the width direction of the diversion groove 3150 can be extended along the involute of the inner periphery of the thrust surface, so as to increase the flow speed of the medium. In the extending direction from the inner peripheral edge to the outer peripheral edge of the thrust surface, the involute is gradually inclined toward the rotation direction of the main shaft 31 .

The depth of each diversion groove 3150 may be 0.1-0.5 mm, so that the depth of the diversion groove 3150 is more suitable, so as not to affect the strength of the thrust plate 315 .

As shown in FIG. 1 , the thrust bearing 50 is formed with a channel 58 communicating with the discharge port 12 , so as to allow the cooling medium thrown out by the thrust plate 315 to flow to the discharge port 12 through the channel 58 .

Fig. 9 is a schematic structural view of the cooler 60 of the present invention; Fig. 10 is a schematic view of the assembly structure of the stator 20 and the cooler 60 of the present invention; Fig. 11 is a schematic left view of Fig. 10; Fig. 12 is an enlarged view of A in Fig. 11 picture.

As shown in FIGS. 9 to 12 , in some embodiments, the motor 1 further includes a cooler 60 . The cooler 60 is installed on the stator 20 and is configured to introduce a cooling medium outside the housing 10 and spray the cooling medium to the outer peripheral surface of the rotor 30 to cool the rotor 30 . The conventional cooling structure of the motor 1 is not easy to cool the outer peripheral surface of the rotor 30, so that the cooling effect of the rotor 30 is not good. The present invention uses spraying to cool the outer peripheral surface of the rotor 30, so that the cooling effect of the rotor 30 is very good, so that the motor 1 has higher operating efficiency and better reliability.

Specifically, as shown in FIG. 9 , the cooler 60 includes an annular main pipe 61 , a liquid inlet pipe 62 and a plurality of branch pipes 63 . Wherein, the central axis of the annular manifold 61 is parallel to the axial direction of the stator 20 and is a hollow ring. The annular manifold 61 is arranged at one axial end of the stator 20 , for example abutting against the axial end surface of the stator 20 . The liquid inlet pipe 62 is connected to the annular main pipe 61 to inject cooling medium into the annular main pipe 61 . A plurality of branch pipes 63 extend from various places in the circumferential direction of the annular main pipe 61 and communicate with the annular main pipe 61 . A plurality of branch pipes 63 are arranged on the inner peripheral portion of the stator 20 extending along the axial direction of the stator 20, and each branch pipe 63 is provided with a plurality of injection holes 631 for spraying the cooling medium introduced from the annular main pipe 61 to the The outer peripheral surface of the rotor 30 cools the outer peripheral surface of the rotor 30 . In FIG. 9 , for simplified illustration, only one branch pipe 63 shows the spray hole 631 , and the spray holes 631 of the other branch pipes 63 are not shown.

In this embodiment, a plurality of branch pipes 63 extend along the axial direction of the stator 20 at the inner periphery of the stator 20 , so as to extend into the interior of the motor 1 to cool the rotor 30 without occupying additional space. Moreover, the cooler 60 utilizes a plurality of branch pipes 63 to spray in all directions, so the coverage area is very large. It can be seen that the structural design of this cooler of the present invention is very practical and ingenious.

In some embodiments, as shown in FIG. 9 , the end of each branch pipe 63 connected to the annular main pipe 61 is the first end, and the other end is the second end. The inventors realized that the inner pressure of the branch pipe 63 is higher closer to its inlet (first end), and the inner pressure is lower the farther away from the inlet. Therefore, in the direction from the first end of the branch pipe 63 to the second end, its cross-section becomes larger gradually, in other words, the farther the branch pipe 63 is away from the annular main pipe 61, the thicker it is, so that the length of the branch pipe 63 everywhere The injection flow rate of each injection hole 631 is the same or the difference is smaller, so that the cooling of the rotor 30 in the axial direction is more uniform, so that the cooling effect is better and unfavorable thermal deformation is avoided.

Similarly, in the direction from the first end to the second end of the branch pipe 63 , the diameter of the injection hole 631 can also be gradually increased. That is, the closer to the first end of the branch pipe 63 the diameter of the injection hole 631 becomes smaller. This can also make the spraying flow rate of each spraying hole 631 everywhere in the length direction of the branch pipe 63 consistent or have a smaller difference.

In some embodiments, as shown in FIG. 1 , FIG. 10 and FIG. 12 , each branch pipe 63 can be embedded in the notch of the iron core 21 of the stator 20 . The stator 20 includes an iron core 21 and a winding 22. The iron core 21 is formed with a plurality of teeth 211 uniformly distributed along its circumference, and a slot 212 is formed between every two adjacent teeth 211. The area of the outer peripheral surface of the slot 212 adjacent to the teeth 211 is a slot mouth. In this embodiment, the branch pipe 63 is embedded in the notch without occupying any extra space and without any modification to the structure of the stator 20 .

Further, the cross-sectional shape of each branch pipe 63 can be matched with the notch, so as to be inserted into the notch with a unique posture, speed up the insertion speed, and avoid wrong insertion direction. Each branch pipe 63 can also be rotatably connected to the annular main pipe 61, and the rotation axis is parallel to its own length direction, so that the branch pipe 63 can be rotated to an optimal posture so as to fit into the notch better.

FIG. 13 is a schematic diagram of another embodiment of the stator 20; FIG. 14 is an enlarged view of B in FIG. 13 .

As shown in FIG. 13 and FIG. 14 , the difference between this embodiment and the embodiment in FIG. 9 to FIG. 12 is that the structure of the iron core 21 of the stator 20 is improved. The inner peripheral surface of each tooth 211 of the iron core 21 of the stator 20 is provided with a groove 2110, and the groove 2110 runs through the axial two ends of the tooth 211, so as to improve the turbulence degree of the air gap between the stator and the rotor, and accelerate the rotation of the rotor. The heat conduction between the outer peripheral surface of the rotor 30 and the air gap accelerates the cooling speed of the rotor 30 . The value range of the depth h of the groove 2110 is 0.5-1.5 mm, and the value range of the width c is 1-3 mm.

Fig. 15 is a partial schematic view of the motor 1 at its thrust bearing 50 according to an embodiment of the present invention.

As shown in FIG. 15 , in some embodiments of the present invention, the motor 1 includes a housing 10 , a stator 20 , a rotor 30 and a thrust bearing 50 , and a thrust plate 315 is formed on the main shaft 31 of the rotor 30 .

The thrust bearing 50 includes two magnetically permeable cores 51 , a permanent magnet ring 52 and a non-magnetically permeable ring 53 . The two permeable cores 51 are respectively located on two axial sides of the thrust plate 315 and spaced apart from the two thrust surfaces of the thrust plate 315 , and are fixed to the inner wall of the casing 10 . The permeable core 51 can be made of silicon steel sheet or electrical iron. The permanent magnet ring 52 is fixed on the inner wall of the casing 10 opposite to the outer peripheral surface of the thrust plate 315 . The magnetic non-permeable ring 53 is fixed on the inner peripheral surface of the permanent magnet ring 52 and spaced apart from the outer peripheral surface of the thrust plate 315 , and the non-magnetic conductive ring 53 is made of aluminum alloy or copper alloy. The thickness of the non-magnetic permeable ring 53 is greater than or equal to 0.2 mm. The gap between the two magnetically conductive cores 51, the nonmagnetically conductive ring 53 and the thrust plate 315 is filled with a magnetic fluid 55 to form a magnetic circuit with the two magnetically conductive cores 51, the nonmagnetically conductive ring 53 and the thrust plate 315 , realize the magnetic fluid 55 seal, avoid or reduce the leakage of refrigerant and lubricating oil, and make the compressor run more efficiently and more reliably.

As shown in FIG. 15 , each permeable core 51 is ring-shaped, and is sleeved on the main shaft 31 . Moreover, each permeable core 51 has an annular groove 512 extending around the main shaft 31 on one side facing the thrust surface. The thrust bearing 50 also includes two magnetic isolation rings 54 , which are located on both axial sides of the thrust plate 315 and are sleeved on the main shaft 31 . A plurality of protruding rings 541 having a diameter larger than the rest of the magnetic isolation ring 54 are formed on the outer peripheral surface of the end section of each magnetic isolation ring 54 away from the thrust plate 315 to prevent the magnetic fluid 55 from flowing out. The protrusion ring 541 protrudes from the rest of the magnetic isolation ring 54 to a height of n, and the gap between the outer peripheral surface of the magnetic isolation ring 54 and the inner peripheral surface of the magnetic permeable core 51 is m, satisfying 0.3≤n/m≤0.5.

The root of each thrust surface has a step portion 3102, and the width of the step portion 3102 is equal to the width of the gap between the permeable core 51 and the thrust surface. One end of each magnetic isolation ring 54 abuts against the end surface of the stepped portion 3102 , so that one end surface of the magnetic permeable core 51 (the end surface close to the thrust plate 315 ) is flush with one end surface of the magnetic isolation ring 54 . The length of the magnetically spaced ring 54 is greater than the length of the magnetically permeable core 51, so that the other end face of the magnetically spaced ring 54 protrudes from the other end face of the magnetically permeable core 51, so that a plurality of raised rings 541 are directed toward the magnetically permeable core 51. The projection of falls outside the inner peripheral surface of the magnetically permeable core 51, so as to block the magnetic fluid 55 conveniently.

In the embodiment of the present invention, the above-mentioned series of optimized designs are carried out on the shape, material, and size of the magnetically conductive core 51, the non-magnetically conductive ring 53, and the magnetically isolated ring 54, so that the sealing performance of the magnetic fluid 55 sealing structure is better, and the operation is more reliable. , lower failure rate.

On the other hand, the present invention also provides a compressor, which includes the motor 1 as described in any one of the above embodiments, so that the motor 1 drives the compression part of the compressor to compress the gas. The compressor can be in the form of a centrifugal compressor, a screw compressor, etc., and the present invention does not limit the compression form thereof.

So far, those skilled in the art should appreciate that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, the disclosed embodiments of the present invention can still be used. Many other variations or modifications consistent with the principles of the invention are directly identified or derived from the content. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

A motor for a compressor, comprising:

stator; and

The rotor is rotatably arranged inside the stator, including a main shaft and a permanent magnet sleeved on it. A central flow channel extending along the axial direction is opened inside the main shaft, and a communication channel is opened on the outer peripheral surface of the main shaft. A plurality of diffusion holes and at least one inflow port of the central channel, the main shaft is sleeved with a through-flow ring at the position of the inflow port;

The through-flow ring is provided with a plurality of through-flow suction ports, so that when the through-flow ring rotates with the main shaft, the liquid cooling medium is sucked into the inlet, so that the cooling medium flows in the central channel to The rotor is cooled, and then thrown out of the main shaft by the plurality of diffuser holes.
The electric machine according to claim 1, wherein,

In the direction from the inner circumference to the outer circumference of the through-flow ring, each of the through-flow suction ports gradually extends obliquely toward the rotation direction of the through-flow ring.
The electric machine according to claim 2, wherein,

In the direction from the inner circumference to the outer circumference of the through-flow ring, the width of each through-flow suction port first decreases and then increases.
The electric machine according to claim 3, wherein,

In the direction of rotation of the through-flow ring, the front wall of each of the through-flow suction ports facing forward is in the shape of a broken line protruding in the middle, and the rear wall facing backward is in the shape of a straight line or a concave curved shape.
The electric machine according to claim 1, wherein,

Each of the inlets is fan-shaped coaxially with the main axis.
The electric machine according to claim 1, wherein,

The plurality of through-flow suction ports are evenly distributed along the circumferential direction of the through-flow ring.
The electric machine according to claim 1, wherein,

The at least one inlet and the plurality of diffuse holes are located on the section of the main shaft that does not cover the permanent magnet, and are respectively located on both sides of the permanent magnet;

The main shaft is fixedly sleeved with a stop ring at the position of the diffuse flow hole, and the stop ring is provided with liquid outlet holes corresponding to the plurality of diffuse flow holes one by one;

The permanent magnet is sandwiched by the through-flow ring and the stop ring so that its axial displacement is constrained.
The electric machine according to claim 7, wherein,

The inner wall of the central channel is provided with a spiral groove coaxial with the main shaft, so as to drive the cooling medium at the inlet to flow toward the plurality of diffuser holes when the rotor rotates.
The electric machine according to claim 1, further comprising:

a housing that seals the stator and the rotor inside it, the main shaft protruding through an opening at the end of the housing to connect to the compression section of the compressor;

A liquid inlet for introducing the cooling medium and a discharge port for discharging the cooling medium are opened on the housing; and

The liquid inlet is used to connect to a throttling device of the refrigeration system, the cooling medium flowing into the liquid inlet is throttled refrigerant, and the outlet is used to communicate with the evaporator of the refrigeration system.
A compressor comprising the motor according to any one of claims 1-9.