Rotor structure using magnetic pole box to fix magnet

Abstract

The invention discloses a rotor structure for fixing a magnet by using a magnetic pole box, relates to the technical field of motor rotors, and aims to solve the problems of poor fixing reliability, inconvenience in installation and adjustment and high maintenance cost of a permanent magnet in the prior art. The top of the rotor support is provided with a rotor iron core, and the bottom end of the annular inner wall of the rotor iron core is connected with symmetrically-distributed pull rods in an inserted mode. The fixing device is reliable in fixing and high in stability, the problem that a permanent magnet of a traditional structure is not reliable in fixing is solved through a multi-stage positioning and elastic pressing structure, rigid supporting is formed by the pull rod and the fastening assembly, circumferential positioning is achieved through cooperation of the check block and the groove, and axial elastic pressing is formed by the limiting ring and the pressing block; triple fixation enables the permanent magnet not to loosen and fall off at a high rotating speed, the rubber pressing block buffers pressure, the fragmentation rate of the permanent magnet is reduced, the distribution uniformity of a magnetic field is improved, the vibration noise of the motor is reduced, and the operation stability is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of motor rotor technology, and in particular to a rotor structure that uses a magnetic pole box to fix a magnet. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in new energy vehicles and industrial drives due to their superior performance, such as high power density and high efficiency. As the core component of a PMSM, one of its core tasks is to reliably and accurately fix the permanent magnets. Currently, the built-in insert-type fixing method embeds the magnets into the magnetic slots stamped inside the rotor core, relying on the rotor laminations' own "magnetic bridge" structure or additional end clips and stops for mechanical restraint. The magnetic bridge area is usually quite narrow, which not only increases magnetic reluctance and reduces the utilization rate of the permanent magnets but also generates additional iron losses. Furthermore, using auxiliary fixing components such as clips requires additional processes such as welding, riveting, or press-fitting, which not only increases process complexity but also causes rotor deformation due to welding stress.

[0003] However, the existing rotor structure that uses a magnetic pole box to fix the magnet has obvious shortcomings in practical applications.

[0004] On the one hand, permanent magnets have poor fixing reliability and are prone to displacement. Traditional fixing methods mostly use a single adhesive or snap-fit ​​structure. When the motor rotates at high speed, the permanent magnet is prone to loosening, shifting or even falling off due to centrifugal force, resulting in uneven magnetic field distribution, increased motor vibration and noise, and in severe cases, motor burnout. On the other hand, the fixing force of some structures is uncontrollable, and excessive compression can cause the permanent magnet to break, affecting the motor's lifespan.

[0005] On the other hand, installation and adjustment are inconvenient and maintenance costs are high. The installation of permanent magnets with traditional structures requires high-precision alignment, but lacks a convenient adjustment mechanism. A single installation takes ≥30 minutes. When the permanent magnet demagnetizes or is damaged and needs to be replaced, the entire rotor needs to be disassembled, resulting in low maintenance efficiency and easy damage to other components, which increases the cost of use. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention provides a rotor structure that uses a magnetic pole box to fix the magnet, which overcomes the shortcomings of the prior art and effectively solves the problems of poor reliability of permanent magnet fixing, inconvenient installation and adjustment, and high maintenance cost in the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A rotor structure for fixing magnets using a magnetic pole box includes a rotating shaft, a rotor support fixed to the top of the rotating shaft, and a rotor core disposed on the top of the rotor support. Symmetrically distributed pull rods are inserted into the bottom end of the annular inner wall of the rotor core, and a support ring is placed on the top of the pull rod. A permanent magnet is placed on the top of the support ring, and the top of the permanent magnet abuts against a limiting ring. The top end of the annular outer wall of the rotor core is fixed with equidistantly distributed limiting components, and the limiting components include a fixing block, a positioning screw welded to the top of the fixing block, a positioning ring sleeved on the wall of the positioning screw, a connecting rod welded to one side of the annular outer wall of the positioning ring, a connecting ring welded to one end of the connecting rod, an adjusting screw screwed to the top of the connecting ring, and a pressure block fixed to the bottom of the adjusting screw.

[0008] Furthermore, the rotor core has insertion holes on both sides of its annular outer wall, and the insertion holes are connected to the pull rod.

[0009] The clearance between the insertion hole and the pull rod is .mm, ensuring that the pull rod can be inserted smoothly and provide stable support; the pull rod surface is chrome-plated to improve wear resistance and corrosion resistance, prevent rust and jamming after long-term use, and ensure the connection stability between the rotor core and the rotor support.

[0010] Furthermore, the top two ends of the pull rod and the top four corners of the rotor bracket are provided with screw holes, and fastening screws are screwed into the screw holes, with fastening nuts screwed into the top of the fastening screws.

[0011] The screw hole and the fastening screw cooperate to firmly connect the rotor core, the tie rod and the rotor support through the pre-tightening force of the fastening nut, ensuring that there is no relative displacement of the three when rotating at high speed and improving the overall structural rigidity.

[0012] Furthermore, the rotor core and the rotor support are fastened together by a tie rod, a fastening screw, and a fastening nut, and the height of the support ring is higher than the height of the fastening nut.

[0013] The support ring is higher than the fastening nut by -mm to prevent the permanent magnet from directly contacting the fastening nut and to prevent the bottom of the permanent magnet from being worn. At the same time, the support ring provides a uniform support surface for the permanent magnet, ensuring that the permanent magnet is subjected to balanced forces and reducing the risk of breakage caused by excessive local stress.

[0014] Furthermore, the top two sides of the annular outer wall of the permanent magnet are fixed with blocks, and the annular inner wall of the rotor core is provided with grooves distributed at equal intervals, with the blocks and grooves forming an interlocking fit.

[0015] The combination of the stop and the groove provides circumferential positioning for the permanent magnet, preventing it from sliding circumferentially during rotation; the inner wall of the groove is polished to reduce frictional damage when the stop is inserted, ensuring positioning accuracy.

[0016] Furthermore, the outer diameters of both the support ring and the positioning ring are adapted to the inner diameter of the rotor core.

[0017] The outer diameter of the support ring and the positioning ring forms a transition fit with the inner diameter of the rotor core, ensuring that both can be accurately embedded into the rotor core, which not only guarantees installation stability but also facilitates disassembly and maintenance; the top of the support ring and the bottom of the positioning ring are machined with guide chamfers to facilitate the installation and positioning of the permanent magnet and the limiting ring.

[0018] Furthermore, the positioning screw has a positioning nut screwed into its wall, and the positioning ring, connecting rod, and connecting ring are fastened together with the rotor core through the positioning nut.

[0019] The positioning screw and positioning nut work together. By adjusting the position of the positioning nut, the height of the positioning ring can be fixed, thereby adjusting the preload of the limiting ring on the permanent magnet. This ensures that the permanent magnet is reliably fixed axially, while avoiding excessive compression that could cause breakage.

[0020] Furthermore, the pressure block is made of rubber, and the bottom of the pressure block may have anti-slip threads.

[0021] The pressure block has good elasticity and wear resistance, which can buffer the pressure of the adjusting screw and avoid hard contact damage to the surface of the permanent magnet; the anti-slip threads at the bottom can increase the friction with the permanent magnet, further preventing the permanent magnet from moving axially and improving the reliability of fixing.

[0022] The beneficial effects of this invention are as follows: With reliable fixation and strong stability, this system solves the problem of unreliable permanent magnet fixation in traditional structures through a multi-level positioning and elastic clamping structure. The pull rod and fastening components form a rigid support, the stop block and groove cooperate to achieve circumferential positioning, and the limit ring and pressure block form axial elastic clamping. This triple fixation ensures that the permanent magnet does not loosen or fall off at high speeds. The rubber pressure block buffers the pressure, reducing the breakage rate of the permanent magnet, improving the uniformity of the magnetic field distribution, reducing motor vibration and noise, and significantly improving operational stability. Easy to install and highly efficient to maintain, this product utilizes adjustable limit components and a modular design to improve upon the traditional structure's difficulties in installation and maintenance. The positioning ring height and adjusting screw can be adjusted separately, enabling rapid positioning of the permanent magnet without the need for high-precision alignment tools. When replacing the permanent magnet, simply loosen the positioning nut and adjusting screw to remove the component without disassembling the entire rotor, thus meeting the needs of efficient production and rapid maintenance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of a rotor structure that uses a magnetic pole box to fix a magnet, as proposed in this invention. Figure 2 This is a schematic diagram of the connection structure between the rotor core and the rotor support of a rotor structure that uses a magnetic pole box to fix the magnet, as proposed in this invention. Figure 3 This is a schematic diagram of the rotor core structure of a rotor structure that uses a magnetic pole box to fix the magnet, as proposed in this invention. Figure 4 This is a schematic diagram of a permanent magnet structure for a rotor structure that uses a magnetic pole box to fix the magnet, as proposed in this invention. Figure 5 This is a schematic diagram of a limiting component structure for a rotor structure that uses a magnetic pole box to fix a magnet, as proposed in this invention.

[0024] In the diagram: 1. Shaft; 2. Rotor support; 3. Rotor core; 4. Tie rod; 5. Support ring; 6. Fastening screw; 7. Fastening nut; 8. Permanent magnet; 9. Stop block; 10. Limiting ring; 11. Limiting assembly; 12. Fixing block; 13. Positioning screw; 14. Positioning ring; 15. Positioning nut; 16. Connecting rod; 17. Connecting ring; 18. Adjusting screw; 19. Pressure block. Detailed Implementation

[0025] 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. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0026] Example: Reference Figure 1-5 A rotor structure that uses a magnetic pole box to fix a magnet includes a rotating shaft 1, a rotor support 2 fixed to the top of the rotating shaft 1, a rotor core 3 set on the top of the rotor support 2, symmetrically distributed pull rods 4 inserted into the bottom of the annular inner wall of the rotor core 3, a support ring 5 placed on the top of the pull rods 4, a permanent magnet 8 placed on the top of the support ring 5, and a limit ring 10 abutting the top of the permanent magnet 8. A limit component 11 with equal distances is fixed to the top of the annular outer wall of the rotor core 3. The limit component 11 includes a fixing block 12, a positioning screw 13 welded and fixed to the top of the fixing block 12, a positioning ring 14 sleeved and movable on the wall of the positioning screw 13, a connecting rod 16 welded and fixed to one side of the annular outer wall of the positioning ring 14, a connecting ring 17 welded and fixed to one end of the connecting rod 16, an adjusting screw 18 screwed to the top of the connecting ring 17, and a pressure block 19 fixed to the bottom of the adjusting screw 18.

[0027] Both sides of the annular outer wall of the rotor core 3 are provided with insertion holes, which are connected to the pull rod 4. The gap between the insertion hole and the pull rod 4 is 0.1mm, which ensures that the pull rod 4 can be smoothly inserted and provides stable support. The surface of the pull rod 4 is chrome-plated to improve wear resistance and corrosion resistance, prevent rust and jamming after long-term use, and ensure the connection stability between the rotor core 3 and the rotor support 2. The top two ends of the pull rod 4 and the top four corners of the rotor support 2 are provided with screw holes, and fastening screws 6 are screwed into the screw holes. Fastening nuts 7 are screwed into the top of the fastening screws 6. The screw holes and fastening screws 6 are engaged, and the pre-tightening force of the fastening nuts 7 firmly connects the rotor core 3, the pull rod 4 and the rotor support 2, ensuring that there is no relative displacement of the three when rotating at high speed and improving the overall structural rigidity. The rotor core 3 and the rotor support 2 are connected by the pull rod 4, the fastening screws 6 and the fastening nuts 7 to form a tight fit. The height of the support ring 5 is higher than the height of the fastening nuts 7. The support ring 5 is 75-10mm higher than the fastening nut to prevent the permanent magnet 8 from directly contacting the fastening nut 7 and to prevent the bottom of the permanent magnet 8 from being worn. At the same time, the support ring 5 provides a uniform support surface for the permanent magnet 8, ensuring that the permanent magnet 8 is subjected to balanced forces and reducing the risk of breakage due to excessive local stress.

[0028] Both sides of the top of the annular outer wall of the permanent magnet 8 are fixed with blocks 9. The annular inner wall of the rotor core 3 has grooves distributed at equal intervals. The blocks 9 and the grooves form an insertion fit. The fit between the blocks 9 and the grooves provides circumferential positioning for the permanent magnet 8 and prevents circumferential sliding of the permanent magnet 8 during rotation. The inner wall of the groove is polished to reduce frictional damage when the blocks 9 are inserted and ensure positioning accuracy. The outer diameters of the support ring 5 and the positioning ring 14 are adapted to the inner diameter of the rotor core 3. The outer diameters of the support ring 5 and the positioning ring 14 form a transition fit with the inner diameter of the rotor core 3 to ensure that they can be accurately embedded into the rotor core 3, which ensures installation stability and facilitates disassembly and maintenance. The top of the support ring 5 and the bottom of the positioning ring 14 are machined with guide chamfers to facilitate the installation and positioning of the permanent magnet 8 and the limiting ring 10. A positioning nut 15 is screwed onto the wall of rod 13. The positioning ring 14, connecting rod 16, and connecting ring 17 are fastened to the rotor core 3 through the positioning nut 15. The positioning screw 13 cooperates with the positioning nut 15. By adjusting the position of the positioning nut 15, the height of the positioning ring 14 can be fixed, thereby adjusting the preload of the limiting ring 10 on the permanent magnet 8, ensuring reliable axial fixation of the permanent magnet 8, and avoiding excessive compression that could lead to breakage. The pressure block 19 is made of rubber and may have anti-slip threads at the bottom. The pressure block 19 has good elasticity and wear resistance, which can buffer the pressure of the adjusting screw 18 and avoid hard contact damage to the surface of the permanent magnet 8. The anti-slip threads at the bottom can increase the friction with the permanent magnet 8, further preventing axial movement of the permanent magnet 8 and improving the reliability of fixation.

[0029] For the shaft and support: Shaft 1 is made of 40CrNiMoA alloy structural steel, with a diameter of 50mm and a length of 300mm. It is heat-treated and the surface is finely ground to ensure rotational accuracy. The top of shaft 1 is fixed to rotor support 2 by a key connection. Rotor support 2 is made of QT450-10 ductile iron and is disc-shaped. M10 screw holes are machined at the four corners of the top for connecting and fastening screws 6. The surface of the support is coated with anti-rust paint to improve corrosion resistance and adapt to use in humid environments.

[0030] For the rotor core and tie rod: The rotor core 3 is made of 0.35mm thick silicon steel sheets, with an outer diameter of 250mm, an inner diameter of 180mm, and a stacking coefficient ≥0.95. Both ends are fixed with pressure rings. The annular outer wall of the core has symmetrical insertion holes on both sides, which are clearance fit with the tie rod 4. The top two ends of the tie rod 4 are machined with M10 screw holes, which are fitted with fastening screws 6. The preload is applied by fastening nuts 7 to firmly fix the rotor core 3 on the rotor support 2, ensuring that the coaxiality between the core and the support is ≤0.05mm.

[0031] Regarding the permanent magnet and positioning components: The permanent magnet 8 is made of neodymium iron boron (N52) material, has an arc-shaped structure, and is nickel-plated to improve corrosion resistance. The top two sides of the annular outer wall of the permanent magnet 8 are fixed with epoxy resin to the stop blocks 9. The stop blocks 9 are fitted with the grooves on the inner wall of the rotor core 3 to achieve circumferential positioning. The support ring 5 is placed on top of the pull rod 4 to provide bottom support for the permanent magnet 8. The top of the support ring 5 is machined with a positioning groove 0.5mm deep, which fits with the protrusion at the bottom of the permanent magnet 8 to further prevent radial slippage.

[0032] For the limiting component: the fixing block 12 is fixed to the top of the annular outer wall of the rotor core 3 by welding. The weld height is 5mm and no defects are found after flaw detection. The positioning screw 13 is fully welded to the fixing block 12. The positioning ring 14 is sleeved on the positioning screw 13 and cooperates with the positioning nut 15 to achieve height fixation. The two ends of the connecting rod 16 are welded to the positioning ring 14 and the connecting ring 17 respectively. The top of the connecting ring 17 is machined with an M6 screw hole to cooperate with the adjusting screw 18. The bottom of the adjusting screw 18 is connected to the fixing block 19 by thread. The bottom of the fixing block 19 is machined with anti-slip threads to ensure tight contact with the top of the permanent magnet 8.

[0033] Working principle: Rotor assembly process: First, fix the rotor bracket 2 to the top of the rotating shaft 1 by key connection, ensuring that the coaxiality of the two is ≤0.05mm; place the rotor core 3 on the top of the rotor bracket 2, align the insertion holes on both sides of the core with the screw holes at the four corners of the bracket, insert the pull rod 4 and make its bottom contact with the rotor core 3; install the fastening screw 6 in the screw hole at the top of the pull rod 4 and the screw holes at the four corners of the bracket, put on the fastening nut 7 and pre-tighten it to make the rotor core 3 and the rotor bracket 2 firmly connected.

[0034] Permanent magnet installation and positioning: Apply a thin layer of grease to the top of the support ring 5, place the support ring 5 on the top of the tie rod 4, and ensure that the outer diameter of the support ring 5 is precisely matched with the inner diameter of the rotor core 3; insert the permanent magnet 8 along the groove on the inner wall of the rotor core 3, so that the bottom of the permanent magnet 8 contacts the support ring 5, and at the same time ensure that the stop block 9 is fully embedded in the groove to achieve circumferential positioning; place the limiting ring 10 on the top of the permanent magnet 8, so that the limiting ring 10 is in uniform contact with the top of all the permanent magnets 8, and initially limit the axial displacement of the permanent magnet 8.

[0035] Adjustment of the fixing components: Place the positioning ring 14 on the positioning screw 13 and adjust it to 1-2mm above the top of the limit ring 10. Tighten the positioning nut 15 to fix the height of the positioning ring 14. Rotate the adjusting screw 18 to make the pressure block 19 slowly descend and contact the top of the limit ring 10. Continue to rotate the adjusting screw 18 to make the pressure block 19 produce moderate elastic deformation. The preload is evenly transmitted to the permanent magnet 8 through the limit ring 10 to achieve axial fixation. Check that all permanent magnets 8 are firmly installed to ensure reliable fixation.

[0036] Operation and maintenance mechanism: When the motor is running, the shaft 1 drives the entire rotor structure to rotate. The permanent magnet 8 generates a constant magnetic field, which interacts with the stator winding to output torque. During high-speed rotation, the tie rod 4 and the fastening assembly provide rigid support, the stop block 9 restricts the circumferential sliding of the permanent magnet 8, and the pressure block 19 and the limit ring 10 restrict axial movement. The triple fixation ensures the stable operation of the permanent magnet 8. When maintenance or replacement of the permanent magnet 8 is required, first loosen the adjusting screw 18 to disengage the pressure block 19 from the limit ring 10, then loosen the positioning nut 15 to remove the positioning ring 14 assembly, and then remove the limit ring 10 and the permanent magnet 8. After replacement, reinstall and adjust in reverse order. The entire maintenance process does not require disassembling the rotor body, which is efficient and convenient.

[0037] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rotor structure for fixing a magnet using a magnetic pole box, comprising a rotating shaft (1), characterized in that, The top of the rotating shaft (1) is fixed with a rotor support (2), and the top of the rotor support (2) is provided with a rotor core (3), the annular inner wall bottom end of the rotor core (3) is inserted with symmetrically distributed pull rods (4), and the top of the pull rod (4) is placed with a support ring (5), the top of the support ring (5) is placed with a permanent magnet (8), and the top of the permanent magnet (8) abuts against a limiting ring (10), the top end of the annular outer wall of the rotor core (3) is fixed with equidistantly distributed limiting assemblies (11), and the limiting assembly (11) comprises a fixed block (12), a positioning screw (13) welded on the top of the fixed block (12), a positioning ring (14) movably sleeved on the rod wall of the positioning screw (13), a connecting rod (16) welded on one side of the annular outer wall of the positioning ring (14), a connecting ring (17) welded on one end of the connecting rod (16), an adjusting screw (18) screwed on the top of the connecting ring (17), and a pressing block (19) fixed on the bottom of the adjusting screw (18).

2. The rotor structure of claim 1, wherein the magnetic pole box is fixed to the rotor core by a plurality of bolts. The annular outer wall of the rotor core (3) is provided with a bushing on both sides, and the bushing is inserted with the pull rod (4).

3. The rotor structure of claim 1, wherein the magnetic pole box is fixed to the rotor core by a plurality of bolts. The top of the pull rod (4) is provided with a threaded hole at both ends, and the threaded hole is screwed with a fastening screw (6), and the top end of the fastening screw (6) is screwed with a fastening nut (7).

4. A rotor structure for fixing a magnet using a magnetic pole box according to claim 3, wherein The rotor core (3) and the rotor support (2) are fastened by the pull rod (4), the fastening screw (6) and the fastening nut (7), and the height of the support ring (5) is higher than the height of the fastening nut (7).

5. The rotor structure of claim 1, wherein the magnetic pole box is fixed to the rotor core by a plurality of bolts. The top of the annular outer wall of the permanent magnet (8) is fixed with a stop block (9) on both sides, and the annular inner wall of the rotor core (3) is provided with equidistantly distributed grooves, and the stop block (9) is inserted with the groove.

6. The rotor structure of claim 1, wherein the magnetic pole box is fixed to the rotor core by a plurality of bolts. The outer diameter of the support ring (5) and the positioning ring (14) is matched with the inner diameter of the rotor core (3).

7. The rotor structure of claim 1, wherein the magnetic pole box is fixed to the rotor core by a plurality of bolts. The rod wall of the positioning screw (13) is screwed with a positioning nut (15), and the positioning ring (14), the connecting rod (16) and the connecting ring (17) are fastened with the rotor core (3) through the positioning nut (15).

8. The rotor structure of claim 1, wherein the magnetic pole box is fixed to the rotor core by a plurality of bolts. The pressing block (19) is made of rubber material, and the bottom of the pressing block (19) can have an anti-skid thread.

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