Rotor structure of high-speed motor and high-speed motor thereof

Abstract

The invention relates to the technical field of motors, in particular to a rotor structure of a high-speed motor and the high-speed motor. The rotor structure comprises a rotor shaft, radial bearings installed at the two ends of the rotor shaft, magnetic isolation blocks installed at the two ends of the rotor shaft, magnetic isolation strips arranged at intervals in the axial direction of the rotor shaft and magnetic steel bonded to the rotor shaft in the area defined by the magnetic isolation blocks and the magnetic isolation strips, bodies of the magnetic isolation strips are in a straight strip shape, and a plurality of half-broken gaps are formed in the bodies at intervals in the radial direction. Protruding bolt keys are arranged at the two ends of the body, grooves are formed in the rotor shaft, the magnetic isolation strips are embedded into the grooves through the bolt keys to be fixed, and carbon fibers are wound outside the magnetic steel, the magnetic isolation blocks and the magnetic isolation strips to form a sheath. The rotor structure designed by the invention is light in weight, the magnetic steel is not easy to throw off, eddy currents on the surfaces of the magnetic steel, the magnetic isolation blocks and the magnetic isolation strips are reduced, demagnetization is effectively improved, and the service life of the motor is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a rotor structure of a high-speed motor and the high-speed motor. Background Art

[0002] In the permanent magnet high-speed motor in the prior art, in order to prevent the rotor magnet from being thrown off under the action of centrifugal force, the magnet is usually bonded to the rotor core with an adhesive. However, under the influence of the vibration generated during the operation of the motor during long-term use, the connectivity between the magnet and the adhesive gradually decreases, and there is still a risk of the magnet being thrown off under the action of centrifugal force at high speed. The installation structure of the magnet in the prior art is also prone to eddy current heating on the surface of the magnet, thereby causing the magnet to demagnetize.

[0003] In the prior art, some motors use a segmented oblique pole rotor structure. In this structure, in order to prevent the magnetic steel from falling off, on the one hand, the magnetic steel is directly bonded to the rotor core, and on the other hand, a boss or groove is set on the rotor core to install the magnetic steel in the circumferential direction of the rotor core. The two ends of each segment of magnetic steel are axially fixed by the end cover, and the circumference of each segment of magnetic steel is radially fixed by a stainless steel sheath or a plastic coating process. Because the permanent magnet motor will generate a large temperature during operation, the temperature increase will cause the magnetic steel to lose its magnetism, and the weakening or disappearance of magnetism will cause the magnetic steel to lose its attraction with the matching slot; the boss or groove set on the rotor core will also affect the magnetic path of the rotor core, thereby affecting the performance of the motor; each segment of the rotor magnetic steel in the segmented oblique pole rotor structure needs to be fixed with a spacer and a sheath, which makes the rotor structure have a large number of parts, a complex structure, and low assembly efficiency. Once some of the magnetic steel is damaged and needs to be repaired and replaced, the stainless steel sheath or the surface plastic coating material will be damaged, causing maintenance difficulties and high maintenance costs.

[0004] In addition, in the prior art, most magnets are installed in the circumferential direction of the rotor core and are fixed with some fixing components. Although the reliability of high-speed operation of the rotor is improved, the radial width of the rotor will be increased, which will not only occupy too much space inside the motor, but the increase in the radial size of the rotor will also increase the centrifugal force on the magnets and cause the weight of the motor to increase, and the leakage flux of the magnets will also increase. Summary of the invention

[0005] The present invention firstly discloses a rotor structure of a high-speed motor, which can significantly reduce magnetic leakage of magnetic steel on the rotor shaft, improve the eddy current problem on the surface of the magnetic steel, prevent the magnetic steel from being thrown off due to centrifugal force, and improve the service life of the motor.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: A rotor structure of a high-speed motor comprises a rotor shaft, radial magnetic bearings are respectively arranged at both ends of the rotor shaft, two retaining rings are formed at intervals in the middle of the rotor shaft, the outer diameter of the retaining ring is larger than the outer diameter of the rotor shaft between the two retaining rings, magnetic isolation blocks are respectively arranged on the opposite sides of the two retaining rings along the circumferential direction of the rotor shaft, magnetic isolation strips are arranged at intervals along the axial direction on the rotor shaft between the two retaining rings, the magnetic isolation strips separate the magnetic isolation blocks on each side into a plurality of magnetic isolation block units along the circumferential direction, magnetic steel is arranged in the area enclosed by the magnetic isolation blocks and the magnetic isolation strips, the magnetic steel is formed by splicing a plurality of magnetic steel unit blocks, and the magnetic steel unit blocks and the magnetic isolation block units are both bonded to the rotor shaft; the magnetic isolation strip comprises a straight bar-shaped body, protruding bolt keys are arranged at both ends of the body, grooves matching the bolt keys are arranged at intervals on the retaining rings on each side, the magnetic isolation strip is fixed on the rotor shaft by embedding the bolt keys in the grooves, and a plurality of gaps are arranged at intervals on the body; carbon fiber is wound around the outside of the magnetic isolation blocks, the magnetic isolation strips and the magnetic steel along the circumferential direction to form a sheath.

[0007] Furthermore, the gap is opened along the thickness direction of the body, and the gap extends from the top of the body to both sides respectively, and the gap does not pass through the bottom of the body.

[0008] Furthermore, a thrust plate is provided on the inner side of the radial magnetic bearing on one side of the rotor shaft, and an axial thrust magnetic bearing is installed on the thrust plate.

[0009] Furthermore, protective bearings are respectively provided at both ends of the rotor shaft, and the protective bearing on each side is located outside the radial magnetic bearing.

[0010] Based on the above rotor structure, the present invention also discloses a high-speed motor, including the above rotor structure, a stator, a housing, a front end cover and a rear end cover, wherein the front end cover is located close to the side of the axial thrust magnetic bearing.

[0011] Furthermore, the casing is provided with an air outlet duct, the rear end cover is provided with an air inlet duct, the outer side of the casing is provided with a bypass air duct, the radial magnetic bearing close to the rear end cover is the rear end radial magnetic bearing, the radial magnetic bearing close to the front end cover is the front end radial magnetic bearing, the air inlet of the bypass air duct is connected to the inner cavity between the rear end cover and the rear end radial magnetic bearing, the air outlet of the bypass air duct is connected to the inner cavity between the front end cover and the front end radial magnetic bearing, a stator ventilation hole is axially opened on the stator, and bearing ventilation holes are provided on both the front end radial magnetic bearing and the rear end radial magnetic bearing.

[0012] Furthermore, a wind shield is provided inside the air outlet duct, which divides the inner cavity of the air outlet duct into a first air outlet cavity and a second air outlet cavity. The first air outlet cavity is close to the axial thrust magnetic bearing, and the cold air blown in from the air inlet duct is divided into two air flows, one of which is directly sent to the inner cavity of the front end cover and the front end radial magnetic bearing by the bypass air duct. After passing through the bearing ventilation holes of the front end radial magnetic bearing, this air flow enters the first air outlet cavity and is discharged from the casing through the air outlet duct; the other air flow passes through the bearing ventilation holes of the rear end radial magnetic bearing, flows into the inner cavity between the stator and the axial thrust magnetic bearing along the gap between the stator and the rotor and the stator ventilation holes, and is discharged from the casing through the second air outlet cavity through the air outlet duct.

[0013] Furthermore, the bottom of the wind shield is connected to the casing as a whole, the bottom of the first air outlet cavity is closed, a limiting ring is formed on the inner wall of the casing below the first air outlet cavity, the axial thrust magnetic bearing is installed at the limiting ring, and an annular step is formed on the inner wall of the casing outside the limiting ring, the annular step is located on the side close to the front end radial magnetic bearing, the inner diameter of the annular step is larger than the inner diameter of the limiting ring, and a first air outlet cavity ventilation hole is axially opened on the annular step, one end of the first air outlet cavity ventilation hole is connected to the inner cavity between the front end radial magnetic bearing and the axial thrust magnetic bearing, and the other end of the first air outlet cavity ventilation hole is connected to the first air outlet cavity.

[0014] The rotor structure designed by the present invention eliminates the traditional rotor core, directly adheres the magnetic steel to the rotor shaft, and reinforces the magnetic steel by wrapping carbon fiber around the outside of the magnetic steel, which reduces the radial size of the rotor structure, reduces the weight of the rotor structure, reduces the centrifugal force that the magnetic steel bears when the motor is running at high speed, and more effectively prevents the magnetic steel from being thrown off under high-speed rotation. In addition, the present invention uses magnetic isolation blocks and magnetic isolation strips to separate the regions around the magnetic steel, which can greatly reduce the magnetic leakage of the magnetic steel on the shaft. Furthermore, the magnetic isolation blocks are separated into multiple small magnetic isolation blocks by magnetic isolation strips, and the magnetic steel is formed by splicing several small magnetic steel unit blocks. Semi-interrupted gaps are arranged on the outer surface of the magnetic isolation strip body at intervals. The above designs can reduce the eddy current heating problem generated by the magnetic isolation blocks, magnetic steel and the surface of the magnetic isolation strip, prevent demagnetization caused by eddy current heating, and increase the service life of the motor. The semi-interrupted gap not only reduces the eddy current heating on the surface of the magnetic isolation strip, but also ensures the transmission strength of the magnetic isolation strip force. The magnetic isolation strip and the rotor shaft are fixed with a mortise and tenon structure, which can better transmit torque.

[0015] The high-speed motor designed by the present invention has a cooling air duct set inside the motor, and uses a fan to blow cold air into the casing to cool the inside of the casing. The air inlet of the cold air is usually close to the rear end cover, and the cold air is blown into the casing through the air inlet. Usually, the rear bearing is cooled first, then the stator and rotor are cooled, and then the front bearing is cooled. In the above-mentioned one-way air duct design scheme in the prior art, the temperature of the cold air is already high after it reaches the location of the front bearing, so this single air duct setting has a poor cooling effect on the front bearing. The present invention introduces a bypass air duct on the outside of the casing, and adds another air duct, which divides the cold air entering the casing from the air inlet duct into two paths, one path cools the rear bearing and the stator and rotor respectively, and the other path directly sends the cold air blown into the casing to the front bearing through the bypass air duct to directly cool the front bearing. Compared with the design of the cooling air duct in the prior art, the present invention has a better cooling effect on the front radial magnetic bearing, which helps to increase the service life of the motor. In addition, in order to avoid mutual interference between the two wind flows with different wind pressures and flow rates, the present invention further provides a wind shield at the air outlet duct, and separates the outflow paths of the two wind flows by the wind shield. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the exterior of the rotor structure in the embodiment; Figure 2 for Figure 1 Schematic diagram after removing the sheath; Figure 3 It is a schematic diagram of the structure of the magnetic isolation strip; Figure 4 It is a schematic diagram of the structure of the magnetic steel installation area on the rotor shaft; Figure 5 for Figure 2 Schematic diagram after removing one of the magnetic isolation strips; Figure 6 Schematic diagram of the external structure of the high-speed motor in the embodiment; Figure 7 It is a cross-sectional view of a high-speed motor; Figure 8 It is a cross-sectional view of the high-speed motor in another direction; Fig. 9 is a cross-sectional view of the casing; Fig.10 This is a cross-sectional view of the casing from another perspective.

[0017] Reference numerals: 1. Sleeve; 2. Radial magnetic bearing; 3. Thrust plate; 4. Magnetic steel; 5. Magnetic isolation block; 6. Magnetic isolation strip; 6-1. Main body; 6-2. Bolt key; 6-3. Gap; 7. Rotor shaft; 8. Retaining ring; 9. Groove; 10. Casing; 10-1. Wind shield; 10-2. First air outlet cavity; 10-3. Second air outlet cavity; 10-4. First air outlet cavity ventilation hole; 10-5. Annular step; 10-6. Limiting ring; 11. Front cover; 12. Rear cover; 13. Air inlet duct; 14. Air outlet duct; 15. Bypass air duct; 16. Stator; 16-1. Stator ventilation hole; 17. Protective bearing; 18. Axial thrust magnetic bearing. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0019] This embodiment first discloses a rotor structure for a magnetically suspended high-speed motor, such as Figures 1 to 5 As shown in FIG. 1 , the rotor structure mainly includes a rotor shaft 7, a radial magnetic bearing 2, a thrust plate 3, a sleeve 1, a magnetic steel 4, a magnetic isolation block 5, and a magnetic isolation strip 6. The radial magnetic bearings 2 are respectively installed at both ends of the rotor shaft 7, and a thrust plate 3 is arranged on the rotor shaft 7 near the inner end of the radial magnetic bearing 2 on one side. The middle area of ​​the rotor shaft 7, as shown in FIG. Figure 4 As shown, retaining rings 8 are formed at both ends of the rotor shaft 7, and the retaining rings 8 are arranged along the circumferential direction of the rotor shaft 7. The outer diameter of the retaining rings 8 is larger than the outer diameter of the rotor shaft 7 between the retaining rings 8 at both ends, so that a recessed portion in which the magnetic steel 4 can be embedded is formed between the retaining rings 8. Grooves 9 are arranged at intervals along the circumferential direction on the retaining rings 8 on each side. Magnetic isolation blocks 5 are arranged along the circumferential direction on the inner side of the retaining rings 8 on each side, and the magnetic isolation blocks 5 are fitted with the retaining rings 8. Figure 2 As shown, on the rotor shaft 7 between the retaining rings 8 at both ends, magnetic isolation strips 6 are arranged in an interval manner along the axial direction of the rotor shaft 7. The length of the magnetic isolation strips 6 is greater than the distance between the magnetic isolation blocks 5 at both ends. The magnetic isolation strips 6 separate the magnetic isolation blocks 5 on each side into multiple small-sized magnetic isolation blocks along the circumferential direction, which is beneficial to reduce the eddy current heating problem on the surface of the magnetic isolation blocks 5. The magnetic steel 4 is arranged in the area enclosed by the magnetic isolation blocks 5 and the magnetic isolation strips 6. The magnetic steel 4 in this embodiment is formed by splicing small-sized magnetic steel unit blocks, which can reduce the eddy current heating problem on the surface of the magnetic steel 4. The rotor structure in this embodiment does not have a rotor core, but directly bonds multiple small-sized magnetic steel unit blocks to the rotor shaft 7 with an adhesive, which can reduce the radial size of the rotor structure, reduce the centrifugal force on the magnetic steel 4, and avoid the magnetic steel 4 from being thrown off when the motor rotates at high speed.

[0020] As mentioned above, the small-sized magnetic isolation block 5 is also directly bonded to the rotor shaft 7 by an adhesive, and the magnetic isolation strip 6 is installed on the rotor shaft 7 by a mortise and tenon structure, which can better transmit torque. Figure 3 As shown, the magnetic isolation strip 6 includes a body 6-1, which is a long straight strip. Both ends of the body 6-1 protrude outward to form bolt keys 6-2. The bolt keys 6-2 of the magnetic isolation strip 6 are embedded in the grooves 9 of the retaining ring 8, so that the magnetic isolation strip 6 is fixed on the rotor shaft 7. In order to reduce the eddy current generated on the surface of the magnetic isolation strip 6, a plurality of half-break gaps 6-3 are formed on the body 6-1 at intervals in this embodiment. The so-called half-break refers to the gaps 6-3 formed by the magnetic isolation strip 6. Figure 3 The direction shown is for reference. The gap 6-3 extends from the top of the main body 6-1 to the two sides of the main body 6-1, but does not penetrate the bottom surface of the main body 6-1, so that the bottom of the main body 6-1 is still connected as a whole. This not only ensures the transmission strength of the force on the magnetic isolation strip 6, but the gap 6-3 can also reduce the eddy current heating problem on the surface of the magnetic isolation strip 6.

[0021] After the installation of the magnetic isolation block 5, magnetic isolation strip 6 and magnetic steel 4 is completed in the above manner, in order to further fix the three, carbon fiber is wound around the outside of the magnetic isolation block 5, magnetic isolation strip 6 and magnetic steel 4 in the circumferential direction to form a sheath 1. The carbon fiber is light in weight and helps to reduce the weight of the rotor structure. The sheath 1 in this embodiment is formed by winding, the magnetic isolation block 5 and the magnetic steel 4 are each spliced ​​with small-sized blocks, and the magnetic isolation strip 6 is fixed with a mortise and tenon structure. The above-mentioned configuration structure provides convenience for the maintenance and replacement of the rotor structural components.

[0022] Based on the above rotor structure, this embodiment also discloses a high-speed motor having the above rotor structure, such as Figures 6 to 10 As shown, it mainly includes a housing 10, end covers at both ends of the housing 10, and a stator 16 and a rotor structure located inside the housing 10. To better describe the positional relationship, one end cover is called the front end cover 11, and the other end cover is called the rear end cover 12. The radial magnetic bearing 2 near the front end cover 11 is called the front radial magnetic bearing, and the radial magnetic bearing 2 near the rear end cover 12 is called the rear radial magnetic bearing. An axial thrust magnetic bearing 18 is provided at the thrust plate 3, and protective bearings 17 are provided at both ends of the rotor shaft 7 on the outside of the radial magnetic bearing 2. By providing the protective bearing 17, the radial magnetic bearing 2, and the axial thrust magnetic bearing 18, contactless transmission between the bearing and the rotor is achieved, bearing wear and heating problems at ultra-high speeds are avoided, and the service life of the motor can be extended. The protective bearing 17 is used to support the rotor when the motor is stopped; the radial magnetic bearing 2 generates magnetic force when the motor is running, so that the rotor enters a suspended state and rotates through the magnetic force; the axial thrust magnetic bearing 18 controls the thrust plate 3 through magnetic force, and the thrust plate 3 provides axial thrust to limit the axial displacement of the rotor to prevent misalignment between the stator and the rotor.

[0023] For a magnetically suspended high-speed motor, due to its high speed, the radial magnetic bearing 2 generates a large amount of heat, and a better cooling effect is required. Therefore, the present invention provides a cooling air duct in the housing 10, and blows cold air into the housing 10 through an external fan to cool the components inside the housing 10. Figure 6 As shown, the rear cover 12 is provided with an air inlet duct 13, the air inlet of the air inlet duct 13 faces downward, the housing 10 is provided with an air outlet duct 14 near the top of the front cover 11, the air outlet of the air outlet duct 14 faces upward, and a bypass air duct 15 is also provided on the outside of the housing 10. Figure 7 and Figure 8 As shown, a stator 16 is arranged on the middle outer circumference of the rotor shaft 7, and a plurality of through stator ventilation holes 16 - 1 are axially opened on the edge of the stator 16 , and through bearing ventilation holes are axially opened on both the front radial magnetic bearing 2 and the rear radial magnetic bearing 2 .

[0024] like Figure 7 As shown, the right end of the bypass air duct 15 is the air inlet, and the left end of the bypass air duct 15 is the air outlet. The air inlet of the bypass air duct 15 is connected to the inner cavity between the rear radial magnetic bearing 2 and the rear cover 12, and the air outlet of the bypass air duct 15 is connected to the inner cavity between the front radial magnetic bearing 2 and the front cover 11. In this embodiment, an external bypass air duct 15 is used, and the fan blows cold air into the interior of the housing 10 through the air inlet pipe 13, which can be divided into two air flows, one of which is Figure 7 As shown by the red arrow, the other way is Figure 7 The red arrows indicate the wind flow path, which is mainly used to cool the rear radial magnetic bearing 2, the stator 16 and the rotor structure. Figure 7 and Figure 8 As shown, the cold air blown in from the air inlet pipe 13 first enters the inner cavity between the rear radial magnetic bearing 2 and the rear cover 12, and then flows into the inner cavity between the stator 16 and the rear radial magnetic bearing 2 along the bearing ventilation holes on the rear radial magnetic bearing 2, first cooling the rear radial magnetic bearing 2, and then respectively flows into the inner cavity between the axial thrust magnetic bearing 18 and the stator 16 through the stator ventilation holes 16-1 and the gap between the stator 16 and the rotor, thereby cooling the stator 16, the rotor and the stator coil, and finally flows out of the housing 10 from the air outlet pipe 14. The wind flow path shown by the blue arrow is Figure 7 As shown, one path of the cold air blown into the inner cavity between the rear end radial magnetic bearing 2 and the rear end cover 12 directly enters the bypass air duct 15, and is sent by the bypass air duct 15 to the inner cavity between the front end radial magnetic bearing 2 and the front end cover 11. The temperature of this path of airflow is relatively low, and this path of airflow is utilized to pass through the bearing ventilation holes from the front end of the front shaft radial magnetic bearing 2 to cool the front end radial magnetic bearing 2. The cooling effect is very good, and the airflow after cooling the front end radial magnetic bearing 2 directly flows out of the casing 10 from the air outlet duct 14.

[0025] Since the cooling airflow in this embodiment is divided into two paths, but both flow out from the same outlet pipe 14, in order to avoid the problem of airflow convection caused by interference between the two paths of airflow with different wind pressure and flow rate, this embodiment sets a wind shield 10-1 in the outlet pipe 14 to isolate the outlet confluence of the two paths of airflow. The wind shield 10-1 is directly formed on the housing 10 by integral molding, such as Fig. 9 and Fig.10 As shown, the bottom of the windshield 10-1 is connected to the housing 10 as a whole, and the windshield 10-1 divides the inner cavity of the air outlet pipe 14 into a first air outlet cavity 10-2 and a second air outlet cavity 10-3. The first air outlet cavity 10-2 is located near the front end cover 11, and the bottom of the first air outlet cavity 10-2 is closed. A first air outlet cavity vent 10-4 is opened at the bottom of the left side wall of the first air outlet cavity 10-2, so that the wind flow for cooling the front radial magnetic bearing 2 flows from the first air outlet cavity vent 10-4 into the first air outlet cavity 10-2, and then flows out of the housing 10 through the air outlet pipe 14.

[0026] Following the above, Fig.10 As shown, a limit ring 10-6 is formed on the inner wall of the casing 10 below the first air outlet cavity 10-2, and the axial thrust magnetic bearing 18 is installed at the limit ring 10-6. An annular step 10-5 is formed on the inner wall of the casing 10 on the left side of the limit ring 10-6. The inner diameter of the annular step 10-5 is larger than the inner diameter of the limit ring 10-6. A first air outlet cavity ventilation hole 10-4 is axially opened on the annular step 10-5 near the first air outlet cavity 10-2. One end of the first air outlet cavity ventilation hole 10-4 is connected to the inner cavity between the axial thrust magnetic bearing 18 and the front end radial magnetic bearing 2, and the other end of the first air outlet cavity ventilation hole 10-4 is connected to the first air outlet cavity 10-2. Because the bottom of the first air outlet cavity 10-2 is closed, the axial thrust magnetic bearing 18 fits tightly with the limit ring 10-6, and the airflow flowing through the bearing ventilation hole of the front radial magnetic bearing 2 cannot directly flow into the lower part of the second air outlet cavity 10-3, but can only flow into the first air outlet cavity 10-2 through the first air outlet cavity ventilation hole 10-4. The bottom of the second air outlet cavity 10-3 is not closed, but directly connects the inner cavity between the stator 16 and the axial thrust magnetic bearing 18, so that the airflow after cooling the stator and rotor can directly flow into the air outlet pipe 14 through the second air outlet cavity 10-3, and then flow out of the housing 10.

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A rotor structure of a high-speed motor, comprising a rotor shaft, with radial magnetic bearings disposed at both ends of the rotor shaft, characterized in that: Two retaining rings are formed in the middle of the rotor shaft, and the outer diameter of the retaining rings is larger than the outer diameter of the rotor shaft between the two retaining rings. Magnetic isolation blocks are respectively provided on the opposite sides of the two retaining rings along the circumferential direction of the rotor shaft, and magnetic isolation strips are provided on the rotor shaft between the two retaining rings along the axial direction. The magnetic isolation strips separate the magnetic isolation blocks on each side into multiple magnetic isolation block units along the circumferential direction. The area enclosed by the magnetic isolation blocks and the magnetic isolation strips is provided with magnetic steel, and the magnetic steel is spliced ​​by multiple magnetic steel unit blocks, and the magnetic steel unit blocks and the magnetic isolation block units are both bonded to the rotor shaft; the magnetic isolation strip includes a straight bar-shaped body, and protruding bolt keys are provided at both ends of the body. Grooves matching the bolt keys are provided at intervals on each side of the retaining ring, and the magnetic isolation strip is fixed to the rotor shaft by embedding the bolt keys in the grooves, and multiple gaps are provided at intervals on the body; carbon fiber is wrapped around the outside of the magnetic isolation blocks, magnetic isolation strips and magnetic steel along the circumferential direction to form a sheath.

2. The rotor structure of a high-speed motor according to claim 1, characterized in that: The gap is opened along the thickness direction of the body, and the gap extends from the top of the body to both sides respectively, and the gap does not pass through the bottom of the body.

3. The rotor structure of a high-speed motor according to claim 1, characterized in that: A thrust disk is provided on the inner side of the radial magnetic bearing on one side of the rotor shaft, and an axial thrust magnetic bearing is installed on the thrust disk.

4. The rotor structure of a high-speed motor according to claim 3, characterized in that: Protection bearings are respectively arranged at both ends of the rotor shaft, and the protection bearing on each side is located outside the radial magnetic bearing.

5. A high-speed motor, characterized in that: It comprises the rotor structure as claimed in claim 3 or 4, and a stator, a casing, a front end cover and a rear end cover, wherein the front end cover is located close to the side of the axial thrust magnetic bearing.

6. The high-speed motor according to claim 5, characterized in that: The casing is provided with an air outlet duct, the rear end cover is provided with an air inlet duct, the outer side of the casing is provided with a bypass air duct, the radial magnetic bearing close to the rear end cover is the rear end radial magnetic bearing, the radial magnetic bearing close to the front end cover is the front end radial magnetic bearing, the air inlet of the bypass air duct is connected to the inner cavity between the rear end cover and the rear end radial magnetic bearing, the air outlet of the bypass air duct is connected to the inner cavity between the front end cover and the front end radial magnetic bearing, a stator ventilation hole is axially opened on the stator, and bearing ventilation holes are provided on both the front end radial magnetic bearing and the rear end radial magnetic bearing.

7. The high-speed motor according to claim 6, characterized in that: A wind shield is provided inside the air outlet duct, which divides the inner cavity of the air outlet duct into a first air outlet cavity and a second air outlet cavity. The first air outlet cavity is close to the axial thrust magnetic bearing. The cold air blown in from the air inlet duct is divided into two air flows, one of which is directly sent to the inner cavity of the front end cover and the front radial magnetic bearing by the bypass air duct. After passing through the bearing ventilation holes of the front radial magnetic bearing, the air flow enters the first air outlet cavity and is discharged from the casing through the air outlet duct; the other air flow passes through the bearing ventilation holes of the rear radial magnetic bearing, flows into the inner cavity between the stator and the axial thrust magnetic bearing along the gap between the stator and the rotor and the stator ventilation holes, and is discharged from the casing through the second air outlet cavity through the air outlet duct.

8. The high-speed motor according to claim 7, characterized in that: The bottom of the wind shield is connected to the casing as a whole, the bottom of the first air outlet cavity is closed, a limiting ring is formed on the inner wall of the casing below the first air outlet cavity, the axial thrust magnetic bearing is installed at the limiting ring, and an annular step is formed on the inner wall of the casing outside the limiting ring, the annular step is located on the side close to the front radial magnetic bearing, the inner diameter of the annular step is larger than the inner diameter of the limiting ring, and a first air outlet cavity ventilation hole is axially opened on the annular step, one end of the first air outlet cavity ventilation hole is connected to the inner cavity between the front radial magnetic bearing and the axial thrust magnetic bearing, and the other end of the first air outlet cavity ventilation hole is connected to the first air outlet cavity.

Images