A cooling structure for a magnetically suspended centrifugal compressor motor

Abstract

The invention discloses a cooling structure of a magnetic suspension centrifugal compressor motor, wherein the motor comprises a rotor, a stator and a housing which are sequentially sleeved, and a heat dissipation gap is provided between the rotor and the stator; the stator is fixed on the inner wall of the housing, and heat dissipation areas connected to the heat dissipation gap are provided at both ends of the stator, and an air inlet and an air outlet connected to the heat dissipation area are fixedly provided on the housing; a water cooling channel is provided in the housing, and a water inlet and a water outlet connected to the water cooling channel are fixedly provided on the housing. The advantage of the invention is that the two cooling methods of air cooling and water cooling are combined to dissipate heat together, thereby improving the cooling efficiency of the magnetic suspension motor; the heat dissipation of the thrust bearing and the magnetic suspension bearing inside the motor can be completed, and the heat dissipation efficiency is strong.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic suspension motors, in particular to a cooling structure of a magnetic suspension centrifugal compressor motor. Background Art

[0002] The magnetic levitation high-speed motor has become one of the hot spots in the international electrical engineering field. The main structure is that the blower impeller is directly installed on the extended end of the click shaft, and the rotor is vertically suspended on the active magnetic bearing to achieve direct drive by the high-speed motor. Using a magnetic levitation motor to drive the compressor-expander unit can effectively improve the system performance, and the cooling method of the magnetic levitation motor directly determines whether the motor can operate stably and safely. Since the speed of the magnetic levitation motor is very high, during operation, the heat generated by the motor loss needs to be removed by cooling, otherwise it will easily affect the normal operation of the motor.

[0003] In the prior art, only one of air cooling and water cooling is usually used to cool the motor of the magnetic suspension centrifugal compressor. Regarding the selection of air cooling and water cooling modes, our company has conducted the following research.

[0004] In the Chinese patent literature, the patent number CN202121792227.6 was authorized and announced on February 18, 2022, for a magnetic levitation motor housing and motor that are compatible with water cooling and air cooling systems. The application sets a water cooling channel on the casing, and sets blind holes for air cooling on the first bearing seat and the second bearing seat. The purpose of this application is that when air cooling is used, the blind holes are opened to introduce cooling air. When water cooling is used, the blind holes are not opened and are in a closed state, and the water cooling channel is cooperated to complete the water cooling of the motor.

[0005] Although the existing technology realizes the application of water cooling or air cooling, only one cooling method can be applied in the actual cooling process, and the cooling efficiency is still relatively insufficient. Summary of the invention

[0006] Based on the above-mentioned deficiencies in the prior art, the present application provides a cooling structure for a magnetic levitation centrifugal compressor motor, which combines air cooling and water cooling to dissipate heat together, thereby improving the cooling efficiency of the magnetic levitation motor.

[0007] To achieve the above objectives, the present invention proposes the following technical solutions.

[0008] A cooling structure for a magnetic levitation centrifugal compressor motor, the motor comprising a rotor, a stator and a casing which are sleeved in sequence, a heat dissipation gap being provided between the rotor and the stator; the stator being fixed on the inner wall of the casing, heat dissipation areas communicating with the heat dissipation gap being provided at both ends of the stator, an air inlet and an air outlet communicating with the heat dissipation areas being fixedly provided on the casing; a water cooling channel being provided inside the casing, a water inlet and a water outlet communicating with the water cooling channel being fixedly provided on the casing.

[0009] The motor adopts a cooling method that combines water cooling and air cooling. The outer surface of the motor stator is water-cooled, and the motor rotor, coil and inner ring of the motor stator are air-cooled. The two cooling methods act on the motor at the same time for cooling. Although the rotor, coil and inner ring of the stator are air-cooled, the cooling airflow is further cooled after passing through the water-cooled motor casing at the air inlet, which has a higher cooling efficiency than general air cooling, thereby ensuring an extremely low operating temperature when the motor is running.

[0010] Preferably, a thrust bearing is provided at one end of the rotor, and a heat dissipation hole connected to the heat dissipation zone is provided on the spacer ring of the thrust bearing. When the magnetic levitation motor is working, the thrust plate is suspended at the center of the front and rear thrust bearings, with a gap of 0.5 mm on both sides. At this time, due to the high-speed rotation of the thrust plate, centrifugal force is generated, and a circle of heat dissipation holes is opened on the spacer ring of the thrust bearing. The heat generated by the thrust bearing will be taken out from the heat dissipation holes to achieve the cooling of the thrust bearing.

[0011] Preferably, the front end of the housing is provided with a front end magnetic bearing seat, a front end radial magnetic bearing is provided in the front end magnetic bearing seat, a heat dissipation vent connected to the heat dissipation zone is provided in the front end magnetic bearing seat, and the heat dissipation vent is connected to the heat dissipation zone. A heat dissipation vent is provided on the front end magnetic bearing seat as an air duct, and the front end radial magnetic bearing is completely cooled by heat conduction; the design of the heat dissipation zone and the heat dissipation vent increases the heat dissipation area, and the heat generated by the magnetic bearing is also taken away by water cooling.

[0012] As a preferred embodiment, the housing is made of an aluminum extruded profile motor barrel, and both ends of the housing are sealed by friction stir welding. The motor housing is made of an aluminum extruded profile with high thermal conductivity; friction stir welding is used to seal both ends of the housing, and a circulating axial water channel is formed inside to ensure the heat dissipation capacity of the housing.

[0013] Preferably, the air inlet is located opposite to the coil package on the stator. The air inlet is cooled and dissipated by an external cooling fan and blows air inwards. The air inlet is located opposite to the coil package to ensure that the coil package is fully cooled.

[0014] Preferably, the water cooling channel includes a plurality of axial channels arranged parallel to the axis of the housing, and the axial channels are connected in series with each other. By running water axially, the channel and the water cooling heat dissipation area are lengthened.

[0015] Preferably, twelve axial flow channels are arranged in a circumferential array around the axis of the housing, and the radial cross-section of the axial flow channel is in the shape of an arc, and the central angle of the radial cross-section of the axial flow channel is between 20 and 27 degrees. The axial flow channel corresponds to most of the area of ​​the housing, and the heat dissipation area is large, which ensures the cooling efficiency of the housing and the stator, and the lateral dimension of the axial flow channel is large, which can effectively reduce the water resistance and improve the heat dissipation efficiency.

[0016] Preferably, the air inlet is arranged at the front end of the motor housing, the thrust bearing is arranged in the end of the front magnetic bearing seat, and the heat dissipation hole is connected to the heat dissipation air outlet. When working, the heat dissipation air will enter from the front end, flow out through the gap between the motor stator and the motor rotor, and finally flow out from the rear end coil, thereby ensuring the heat dissipation capacity of the thrust bearing and the magnetic suspension bearing.

[0017] Preferably, the length of the air inlet in the axial direction of the motor is between 1 / 4 and 2 / 5 of the axial length of the stator, so as to ensure the cooling efficiency of the motor stator by the air entering the air inlet.

[0018] The beneficial effects of the present invention are: air cooling and water cooling are combined to dissipate heat together, thereby improving the cooling efficiency of the magnetic suspension motor; the heat dissipation of the thrust bearing and the magnetic suspension bearing inside the motor can be completed, and the heat dissipation efficiency is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 It is a structural schematic diagram of the shell in the present invention.

[0021] Figure 3 yes Figure 2 Cross-sectional view at AA in the middle.

[0022] Figure 4 yes Figure 2 Cross-sectional view at the middle BB.

[0023] Figure 5 It is a cross-sectional view of the position where one end of an axial flow channel is connected to an adjacent axial flow channel.

[0024] Figure 6 yes Figure 5 Cross-sectional view at CC.

[0025] In the figure: rotor 1 thrust disk 101 stator 2 coil 201 heat dissipation gap 202 housing 3 air inlet 301 air outlet 302 water inlet 303 water outlet 304 thrust bearing 4 spacer 401 heat dissipation hole 402 front end magnetic bearing seat 5 front end radial magnetic bearing 501 heat dissipation air outlet 502 front heat dissipation area 503 rear end magnetic bearing seat 6 rear heat dissipation area 601 water cooling channel 7 axial channel 701. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] Embodiment 1,

[0028] A cooling structure for a magnetically suspended centrifugal compressor motor, such as Figure 1 and Figure 2 As shown, the motor includes a rotor 1, a stator 2 and a housing 3 which are sequentially sleeved, the stator 2 is fixed on the inner wall of the housing 3, and the rotor 1 is an integrated structure integrated with the rotating shaft; a heat dissipation gap 202 is separated between the rotor 1 and the stator 2. Both ends of the stator 2 are provided with heat dissipation zones connected to the heat dissipation gap 202, the front end of the stator 2 and the thrust bearing 4 and the front end magnetic bearing seat 5 are gap-opposed to form a front heat dissipation zone 503; the rear end of the stator 2 and the rear end magnetic bearing seat 6 are gap-opposed to form a rear heat dissipation zone 601. An air inlet 301 and an air outlet 302 connected to the heat dissipation zone are fixedly provided on the housing 3; the positions of the air inlet 301 and the air outlet 302 are directly opposite to the coil 201 on the stator 2. The air inlet 301 is arranged at the front end of the housing 3 of the motor, and the position of the air inlet 301 in the axial direction of the motor is adjacent to the front heat dissipation zone 503. When the air inlet 301 takes in air, it passes through the outer side of the coil 201 on the stator 2 and is diverted to the front end magnetic bearing seat 5 and the heat dissipation gap 202. The length of the air inlet 301 in the axial direction of the motor is 8 / 25 of the axial length of the motor stator 2. A thrust bearing 4 is provided at one end of the rotor 1, and a heat dissipation hole 402 connected to the heat dissipation zone is provided on the spacer 401 between the two thrust bearings 4. A front end magnetic bearing seat 5 is provided at the front end of the housing 3, a front end radial magnetic bearing 501 is provided in the front end magnetic bearing seat 5, a heat dissipation vent 502 connected to the heat dissipation zone is provided in the front end magnetic bearing seat 5, and the thrust bearing 4 is arranged in the end of the front end magnetic bearing seat 5, and the heat dissipation hole 402 is connected to the heat dissipation vent 502. The heat dissipation vent 502 is connected to the heat dissipation zone. The rotor 1 is provided with a shoulder to form a thrust plate 101 that matches the thrust bearing 4. When the motor is working, the thrust plate 101 is suspended to the middle position of the thrust bearing 4, and a gap is formed between the thrust plate 101 and the thrust bearings 4 on both sides thereof. The thrust plate 101 rotates to generate centrifugal force to throw out the internal air and heat together, and after passing through the heat dissipation holes 402 and entering the heat dissipation vents 502, they are taken out together by the airflow flowing out of the heat dissipation vents 502, thereby achieving heat dissipation of the thrust bearing 4. A water cooling channel 7 is provided in the housing 3, such as Figures 3 to 6As shown, the water-cooling channel 7 includes a plurality of axial channels 701 arranged parallel to the axis of the housing 3, and the axial channels 701 are connected in series. Specifically, one end of the axial channel 701 is connected to one end of the axial channel 701 on the adjacent side, and the other end of the axial channel 701 is connected to the other end of the axial channel 701 on the adjacent side. The water channel connecting the adjacent axial channels 701 is arranged radially along the housing 3. Twelve axial channels 701 are arranged in a circular array around the axis of the housing 3. The radial cross-section of the axial channel 701 is in the shape of an arc, and the two ends of the radial cross-section of the axial channel 701 are in the shape of a straight line. The straight lines at the two ends of the radial cross-section of the axial channel 701 are at an angle of 30 degrees. There is a fillet transition between the two ends of the radial cross-section of the axial channel and the arc-shaped side of the axial channel 701. The central angle of the radial cross-section of the axial channel 701 is 24 degrees. The housing 3 adopts an aluminum extruded profile motor barrel, and the two ends of the housing 3 are sealed by friction stir welding. The housing 3 is fixed with a water inlet 303 and a water outlet 304 connected to the water cooling channel 7. The water inlet 303 and the water outlet 304 are connected to the external cooling water circuit through a pipeline. The air inlet and the air outlet are connected to the external cooling air circuit. Since the air inlet 301 and the air outlet 302 are arranged through the housing 3, the cooling airflow entering the air inlet 301 will be cooled by the water-cooled housing 3, thereby achieving overall rapid heat dissipation. Pump casings are respectively arranged at both ends of the housing 3 of the motor, and impellers are respectively arranged in the corresponding pump casings at both ends of the rotor 1 shaft of the motor.

[0029] The present application adopts a cooling method combining water cooling and air cooling. The outer surface of the motor stator 2 is water-cooled, and the motor rotor 1, the coil 201 and the inner ring of the motor stator 2 are air-cooled. The two cooling methods act on the motor at the same time for cooling. Although the rotor 1, the coil 201 and the inner ring of the stator 2 are air-cooled, the cooling airflow is further cooled after passing through the water-cooled motor housing 3 at the air inlet 301, which has a higher cooling efficiency than general air cooling, thereby ensuring an extremely low operating temperature when the motor is running. In addition, the present application not only has a heat dissipation method combining water cooling and air cooling to improve the heat dissipation efficiency of the motor, but also optimizes the water-cooling flow channel 7 on the motor housing 3 and the cooling air channel in the motor, further improving the heat dissipation efficiency of the motor as a whole from a structural point of view, and can also complete the heat conduction heat dissipation of the thrust bearing 4, with high heat dissipation efficiency.

Claims

1. A cooling structure for a magnetically suspended centrifugal compressor motor, characterized in that: The motor comprises a rotor, a stator and a shell which are arranged in sequence, and a heat dissipation gap is separated between the rotor and the stator; the stator is fixed on the inner wall of the shell, and heat dissipation zones connected to the heat dissipation gap are arranged at both ends of the stator, and an air inlet and an air outlet connected to the heat dissipation zone are fixedly arranged on the shell; a water cooling channel is arranged in the shell, and a water inlet and a water outlet connected to the water cooling channel are fixedly arranged on the shell; two thrust bearings are arranged at one end of the rotor, and a heat dissipation hole connected to the heat dissipation zone is arranged on the spacer ring between the two thrust bearings, and a boss is arranged on the rotor to form a thrust plate which cooperates with the thrust bearing, and when the motor is working, the thrust plate is suspended to the middle position of the two thrust bearings, and a gap is formed between the thrust plate and the thrust bearings on both sides thereof; a front end magnetic bearing seat is arranged at the front end of the shell, and a front end radial magnetic bearing is arranged in the front end magnetic bearing seat, and a heat dissipation vent connected to the heat dissipation zone is arranged in the front end magnetic bearing seat, and the heat dissipation vent is connected to the heat dissipation zone, and the thrust bearing is arranged in the end of the front end magnetic bearing seat, and the heat dissipation hole is connected to the heat dissipation vent.

2. The cooling structure of a magnetic suspension centrifugal compressor motor according to claim 1 is characterized in that: The shell adopts an aluminum stretched profile motor barrel, and both ends of the shell are sealed by friction stir welding.

3. The cooling structure of a magnetic suspension centrifugal compressor motor according to claim 1 is characterized in that: The position of the air inlet is directly opposite to the coil package on the stator.

4. The cooling structure of a magnetic suspension centrifugal compressor motor according to claim 1 or 2, characterized in that: The water cooling flow channel comprises a plurality of axial flow channels arranged parallel to the axis of the shell, and the axial flow channels are connected in series.

5. The cooling structure of a magnetic suspension centrifugal compressor motor according to claim 4 is characterized in that: The axial flow channels are provided with twelve axial flow channels arranged in a circumferential array around the axis of the shell. The radial cross-section of the axial flow channel is in the shape of an arc, and the central angle of the radial cross-section of the axial flow channel is between 20 and 27 degrees.

6. The cooling structure of a magnetic suspension centrifugal compressor motor according to claim 1, characterized in that: The air inlet is arranged at the front end of the housing of the motor.

7. A cooling structure for a magnetically suspended centrifugal compressor motor according to claim 1, 3 or 6, characterized in that: The length of the air inlet in the axial direction of the motor ranges from 1 / 4 to 2 / 5 of the axial length of the stator.

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