Magnetic isolation structure of rotor, rotor structure and motor

Abstract

The utility model relates to the technical field of motors, in particular to a magnetic isolation structure of a rotor, a rotor structure and a 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 utility model 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] This utility model relates to the field of motor technology, specifically to a rotor magnetic isolation structure, rotor structure, and motor. Background Technology

[0002] In existing permanent magnet high-speed motors, to prevent the rotor magnets from detaching under centrifugal force, the magnets are usually bonded to the rotor core with adhesive. However, under long-term use, the connection between the magnets and the adhesive gradually decreases due to the vibration generated during motor operation. There is still a risk of the magnets detaching under high-speed centrifugal force. The existing magnet mounting structure can also easily cause eddy current heating on the magnet surface, leading to magnet demagnetization.

[0003] In existing technologies, some motors employ a segmented skewed-pole rotor structure. To prevent magnet detachment in this structure, the magnets are either directly bonded to the rotor core, or bosses or grooves are provided on the rotor core to mount the magnets circumferentially. Each magnet segment is axially fixed at both ends by end caps, and radially fixed circumferentially by stainless steel sleeves or plastic coating. Because permanent magnet motors generate significant temperatures during operation, rising temperatures can cause the magnets to lose their magnetism. Weakened or absent magnetism leads to a loss of attraction between the magnet and its slot. The bosses or grooves on the rotor core also affect the magnetic circuit alignment, thus impacting motor performance. Furthermore, each segment of rotor magnet in the segmented skewed-pole rotor structure requires spacers and sleeves for fixation, resulting in a large number of rotor components, complex structure, and low assembly efficiency. Damage to any magnet requiring repair or replacement damages the stainless steel sleeves or plastic coating, leading to difficult and costly repairs.

[0004] In addition, in most existing technologies, magnets are installed in the circumferential direction of the rotor core and fixed with some fixing components. Although this improves the reliability of high-speed rotor operation, it increases the radial width of the rotor. This not only occupies too much space inside the motor, but also increases the centrifugal force on the magnets and the weight of the motor. The leakage flux of the magnets will also increase. Utility Model Content

[0005] This utility model first discloses a magnetic isolation structure for a rotor, which can significantly reduce magnetic leakage of magnets on the rotor shaft and improve the eddy current problem on the surface of the magnets.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A magnetic shielding structure for a rotor includes magnetic shielding blocks and magnetic shielding strips. Magnets are installed in the circumferential direction of the rotor shaft. Magnetic shielding blocks are respectively arranged in the circumferential direction at both ends of the rotor shaft. Multiple magnetic shielding strips are arranged axially at intervals on the rotor shaft between the magnetic shielding blocks at both ends. Magnets are installed in the area enclosed by the magnetic shielding blocks and magnetic shielding strips. The body of the magnetic shielding strip is straight, and multiple gaps are opened radially at intervals on the body.

[0008] Furthermore, the gap extends from the top of the magnetic strip body to both sides, and the gap does not penetrate the bottom of the magnetic strip body.

[0009] Furthermore, protruding keylets are formed at both ends of the magnetic shielding strip body, and retaining rings are formed on the rotor shaft along the circumferential direction on the outer side of each magnetic shielding block. The outer diameter of the retaining rings is larger than the outer diameter of the rotor shaft between the two retaining rings. Grooves matching the keylets are formed at intervals on the retaining rings, and the magnetic shielding strip is fixed by being embedded into the grooves of the retaining rings by the keylets at both ends.

[0010] Furthermore, the length of the magnetic shielding strip is greater than the distance between the magnetic shielding blocks at both ends, and the magnetic shielding strip divides the magnetic shielding blocks at each end into multiple magnetic shielding blocks along the circumferential direction.

[0011] Based on the above-mentioned magnetic shielding structure, this utility model also discloses a rotor structure, including a radial magnetic bearing installed on the rotor shaft and a magnet installed between the magnetic shielding blocks at both ends. The magnet is composed of multiple magnet unit blocks spliced ​​together. The magnet unit blocks are directly bonded to the rotor shaft. Carbon fiber is wound around the magnet, magnetic shielding blocks and magnetic shielding strip to form a protective sleeve.

[0012] Furthermore, a thrust disk is provided at one end of the rotor shaft.

[0013] This utility model also discloses a motor having the above-mentioned magnetic shielding structure.

[0014] This utility model also discloses an electric motor having the above-described rotor structure.

[0015] The rotor structure designed in this invention eliminates the traditional rotor core, directly bonding the magnets to the rotor shaft. The magnets are reinforced with carbon fiber wrapping, reducing the radial dimension and weight of the rotor structure. This also reduces the centrifugal force experienced by the magnets during high-speed motor operation, effectively preventing the magnets from being thrown off at high speeds. Furthermore, this invention uses magnetic shielding blocks and strips to divide the area around the magnets, significantly reducing magnetic leakage on the shaft. Moreover, the magnetic shielding blocks are divided into multiple smaller blocks by the magnetic strips, and the magnets are formed by splicing together several small magnet unit blocks. Semi-interrupted gaps are spaced on the outer surface of the magnetic strip body. All of these designs reduce eddy current heating on the surfaces of the magnetic shielding blocks, magnets, and magnetic strips, preventing demagnetization caused by eddy current heating and improving the motor's lifespan. The semi-interrupted gaps reduce eddy current heating on the surface of the magnetic strips while ensuring the strength of the force transmission. The magnetic strips are fixed to the rotor shaft using a tenon and mortise structure, which better transmits torque. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the external rotor structure in the embodiment;

[0017] Figure 2 for Figure 1 A schematic diagram after the sheath has been removed;

[0018] Figure 3 This is a schematic diagram of the magnetic shielding strip.

[0019] Figure 4 A schematic diagram of the area on the rotor shaft where magnets are mounted.

[0020] Figure 5 for Figure 2 A schematic diagram after removing one of the magnetic strips.

[0021] Figure label:

[0022] 1. Sheath; 2. Radial magnetic bearing; 3. Thrust disc; 4. Magnet; 5. Magnetic shielding block; 6. Magnetic shielding strip; 6-1. Body; 6-2. Bolt key; 6-3. Clearance; 7. Rotor shaft; 8. Retaining ring; 9. Groove. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0024] This embodiment mainly discloses a rotor structure, a magnetic shielding structure for the rotor, and a motor having the above-mentioned rotor structure and magnetic shielding structure for a magnetic levitation high-speed motor, such as... Figures 1 to 5As shown, the rotor structure mainly includes a rotor shaft 7, radial magnetic bearings 2, a thrust disk 3, a sheath 1, magnets 4, magnetic shielding blocks 5, and magnetic shielding strips 6. Radial magnetic bearings 2 are installed at both ends of the rotor shaft 7. A thrust disk 3 is installed on the rotor shaft 7 near the inner end of one of the radial magnetic bearings 2. The middle region of the rotor shaft 7, as shown... Figure 4 As shown, retaining rings 8 are formed at both ends of the rotor shaft 7. The retaining rings 8 are arranged along the circumference of the rotor shaft 7, and the outer diameter of the retaining rings 8 is larger than the outer diameter of the rotor shaft 7 between the two retaining rings 8, forming a recess between the retaining rings 8 into which magnets 4 can be embedded. Grooves 9 are spaced apart along the circumference on each retaining ring 8. Magnetic isolation blocks 5 are arranged along the circumference on the inner side of each retaining ring 8, and the magnetic isolation blocks 5 are in contact with the retaining ring 8. Figure 2 As shown, magnetic shielding strips 6 are arranged at intervals along the axial direction of the rotor shaft 7 between the retaining rings 8 at both ends. The length of the magnetic shielding strips 6 is greater than the distance between the magnetic shielding blocks 5 at both ends. The magnetic shielding strips 6 divide the magnetic shielding blocks 5 on each side into multiple small-sized magnetic shielding blocks along the circumferential direction, which helps to reduce the eddy current heating problem on the surface of the magnetic shielding blocks 5. Magnets 4 are arranged in the area enclosed by the magnetic shielding blocks 5 and the magnetic shielding strips 6. In this embodiment, the magnets 4 are formed by splicing small-sized magnet unit blocks, which can reduce the eddy current heating problem on the surface of the magnets 4. In this embodiment, the rotor structure does not have a rotor core. Instead, multiple small-sized magnet unit blocks are directly glued to the rotor shaft 7 with adhesive. This can reduce the radial dimension of the rotor structure, reduce the centrifugal force on the magnets 4, and prevent the magnets 4 from being thrown off under high-speed rotation of the motor.

[0025] Following the above, the small-sized magnetic shielding block 5 is also directly bonded to the rotor shaft 7 using adhesive, while the magnetic shielding strip 6 is installed on the rotor shaft 7 via a tenon and mortise structure, which can better transmit torque. Figure 3 As shown, the magnetic shielding strip 6 includes a body 6-1, which is a long straight strip. Both ends of the body 6-1 protrude outwards to form key 6-2. The key 6-2 of the magnetic shielding strip 6 is embedded in the groove 9 of the retaining ring 8, thereby fixing the magnetic shielding strip 6 to the rotor shaft 7. To reduce the eddy currents generated on the surface of the magnetic shielding strip 6, in this embodiment, multiple semi-partial gaps 6-3 are also formed at intervals on the body 6-1. The term "semi-partial" refers to... Figure 3 With the direction shown as a reference, the gap 6-3 extends from the top of the body 6-1 to both sides of the body 6-1, but does not penetrate the bottom surface of the body 6-1, so that the bottom of the body 6-1 remains connected as one unit. This ensures the strength of force transmission on the magnetic shielding strip 6, and the gap 6-3 can also reduce the problem of eddy current heating on the surface of the magnetic shielding strip 6.

[0026] After installing the magnetic shielding block 5, magnetic shielding strip 6, and magnet 4 as described above, to further secure them, carbon fiber is wound around the outside of the magnetic shielding block 5, magnetic shielding strip 6, and magnet 4 in a circumferential direction to form a sheath 1. Carbon fiber is lightweight, which helps reduce the weight of the rotor structure. In this embodiment, the sheath 1 is formed by winding; the magnetic shielding block 5 and magnet 4 are each assembled from small blocks; and the magnetic shielding strip 6 is fixed using a tenon and mortise structure. All of these structural features facilitate the maintenance and replacement of rotor components.

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

Claims

1. A magnetic shielding structure for a rotor, characterized in that: It includes magnetic shielding blocks and magnetic shielding strips. Magnets are installed in the circumferential direction of the rotor shaft. Magnetic shielding blocks are set at both ends of the rotor shaft in the circumferential direction. Multiple magnetic shielding strips are set at intervals along the axial direction on the rotor shaft between the magnetic shielding blocks at both ends. Magnets are installed in the area enclosed by the magnetic shielding blocks and magnetic shielding strips. The body of the magnetic shielding strip is straight, and multiple gaps are opened at intervals along the radial direction on the body.

2. The magnetic shielding structure of a rotor according to claim 1, characterized in that: The gaps extend from the top of the magnetic strip body to both sides, but do not penetrate the bottom of the magnetic strip body.

3. The magnetic shielding structure of a rotor according to claim 1, characterized in that: The magnetic shielding strip body has protruding key at both ends. A retaining ring is formed on the rotor shaft on the outer side of the magnetic shielding block at each end along the circumferential direction. The outer diameter of the retaining ring is larger than the outer diameter of the rotor shaft between the two retaining rings. Grooves matching the key are formed at intervals on the retaining ring. The magnetic shielding strip is fixed by being embedded into the groove of the retaining ring by the key at both ends.

4. The magnetic shielding structure of a rotor according to claim 1, characterized in that: The length of the magnetic shielding strip is greater than the distance between the magnetic shielding blocks at both ends, and the magnetic shielding strip divides the magnetic shielding blocks at each end into multiple magnetic shielding blocks along the circumferential direction.

5. A rotor structure, characterized in that: The magnetic shielding structure as described in any one of claims 1-4 further includes a radial magnetic bearing mounted on the rotor shaft and a magnet mounted between the magnetic shielding blocks at both ends. The magnet is constructed by splicing multiple magnet unit blocks, which are directly bonded to the rotor shaft. Carbon fiber is wound around the magnet, magnetic shielding blocks, and magnetic shielding strip to form a protective sleeve.

6. A rotor structure according to claim 5, characterized in that: A thrust disk is provided at one end of the rotor shaft.

7. An electric motor, characterized in that: Including the magnetic shielding structure as described in any one of claims 1-4.

8. An electric motor, characterized in that: Includes the rotor structure as described in claim 5 or 6.

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