Motor rotor, magnetic levitation motor

Abstract

The present invention provides a motor rotor and a magnetic levitation motor, wherein the motor rotor includes a first rotating shaft and a second rotating shaft, the first rotating shaft and the second rotating shaft being coaxial, the first rotating shaft having a first protrusion extending along its axial direction, the second rotating shaft having a first groove extending along its axial direction, the first protrusion being at least partially inserted into the first groove, and the first protrusion and the groove wall of the first groove being pinned together by a first pin. According to the present invention, the first rotating shaft and the second rotating shaft are pinned together by the first pin so that the two form a whole, thereby improving the structural strength and rigidity of the motor rotor, and can also effectively prevent the gap between the sleeve and the adjacent shaft end retaining ring in the prior art, reducing the difficulty of the assembly process while effectively preventing the stress concentration phenomenon at the corner of the gap on the rotating shaft.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor manufacturing, and in particular relates to a motor rotor and a magnetic levitation motor. Background Art

[0002] Magnetic levitation motors utilize the electromagnetic force of magnetic bearings to suspend the motor rotor in mid-air, eliminating mechanical contact and friction between the rotor and stator. This results in low-loss, high-performance motors. While achieving high rotor speeds, they also offer advantages such as zero mechanical wear, low energy consumption, low noise, long life, no need for lubrication or sealing, and no oil contamination. The rotor speed of a magnetic levitation motor is limited only by the tensile strength of the rotor material, allowing for very high circumferential speeds. This makes them increasingly popular in high-speed equipment.

[0003] The rotor structure of a traditional speed-focused hidden-pole high-speed motor consists of a rotor, permanent magnets, and a sheath. This is because during the operation of a high-speed motor, the permanent magnets will be subjected to very large centrifugal forces. Permanent magnets are resistant to compression but not to tension. To prevent them from being damaged under normal working conditions, professional protective measures must be used to provide strength protection for the permanent magnets.

[0004] Existing high-speed magnetic bearing rotors all use a sheath to protect the magnetic steel (permanent magnet). The sheath is fitted onto the magnetic steel by means of a shrink sleeve. The heating temperature is between 500 and 700°C, and the sheath expands and contracts with heat. After cooling, a gap is formed between the front and rear short shafts and the ends of the sheath. Figure 1 As shown in the figure; in actual use, when the main shaft is subjected to a strong impact, the rotor shaft gap will bend and deform after the collision, affecting the stable suspension operation of the rotor; through actual measurement and simulation analysis, the existence of this gap causes the sleeve to not be close to the shaft ends of the front and rear short shafts. In addition, the sleeve has an interference fit with the front and rear short shafts, and the corner of the gap is a stress concentration point, which is most likely to cause bending and deformation, thereby reducing the reliability of the entire rotor. Summary of the Invention

[0005] Therefore, the present invention provides a motor rotor and a magnetic levitation motor to overcome the shortcomings of stress concentration, low structural strength and rigidity caused by the rotor rigidity relying solely on the interference fit connection of the sheath in the prior art.

[0006] In order to solve the above problems, the present invention provides a motor rotor, including a first rotating shaft and a second rotating shaft, the first rotating shaft and the second rotating shaft are coaxial, the first rotating shaft has a first protrusion extending along its axial direction, the second rotating shaft has a first groove extending along its axial direction, the first protrusion is at least partially inserted into the first groove, and the first protrusion and the groove wall of the first groove are pinned together by a first pin.

[0007] Preferably, the first rotating shaft also has a second groove extending along its axial direction, and the second rotating shaft also has a second protrusion extending along its axial direction, the second protrusion is at least partially inserted into the second groove, and the second protrusion and the groove wall of the second groove are pinned together by a second pin.

[0008] Preferably, the first rotating shaft also includes a first shaft extension, the first protrusion is located at one axial end of the first shaft extension, the first protrusion includes a first magnetic steel sleeve section and a first pin-connected insertion section located on the side of the first magnetic steel sleeve section away from the first shaft extension; the second rotating shaft also includes a second shaft extension, the second protrusion is located at one axial end of the second shaft extension, the second protrusion includes a second magnetic steel sleeve section and a second pin-connected insertion section located on the side of the second magnetic steel sleeve section away from the second shaft extension.

[0009] Preferably, any plane perpendicular to the axial direction of the first rotating shaft is a first plane, and the projection of the first magnetic steel sleeve segment on the first plane is semicircular, and / or the projection of the first pin-connected plug-in segment on the first plane is rectangular; any plane perpendicular to the axial direction of the second rotating shaft is a second plane, and the projection of the second magnetic steel sleeve segment on the second plane is semicircular, and / or the projection of the second pin-connected plug-in segment on the second plane is rectangular.

[0010] Preferably, on the first plane, the projection of the first pin-connected plug-in section is within the projection range of the first magnetic steel sleeve section; and / or, on the second plane, the projection of the second pin-connected plug-in section is within the projection range of the second magnetic steel sleeve section.

[0011] Preferably, the connection between the first shaft extension body and the first protrusion has a first shaft end retaining ring, the second groove extends from the first protrusion toward one side of the first shaft extension body, and the first pin hole constructed on the groove wall of the second groove is located on the side of the first shaft end retaining ring away from the first protrusion; and / or, the connection between the second shaft extension body and the second protrusion has a second shaft end retaining ring, the first groove extends from the second protrusion toward one side of the second shaft extension body, and the second pin hole constructed on the groove wall of the first groove is located on the side of the second shaft end retaining ring away from the second protrusion.

[0012] Preferably, a first pin stop ring is mounted on the first shaft extension, and the mounting position of the first pin stop ring is adapted to the first pin hole; and / or a second pin stop ring is mounted on the second shaft extension, and the mounting position of the second pin stop ring is adapted to the second pin hole.

[0013] Preferably, the first shaft extension body is also provided with a first bearing rotor lamination, and the first bearing rotor lamination is located on the side of the first pin stop ring away from the first protrusion; and / or, the second shaft extension body is also provided with a second bearing rotor lamination, and the second bearing rotor lamination is located on the side of the second pin stop ring away from the second protrusion.

[0014] Preferably, the first shaft extension body is also provided with a first bearing rotor retaining ring, and the first bearing rotor retaining ring is located on the side of the first bearing rotor lamination away from the first protrusion; and / or, the second shaft extension body is also provided with a second bearing rotor retaining ring, and the second bearing rotor retaining ring is located on the side of the second bearing rotor lamination away from the second protrusion.

[0015] Preferably, the outer circumferences of the first protrusion and the second protrusion between the first shaft end retaining ring and the second shaft end retaining ring are sleeved with an annular magnetic steel, and the outer circumference of the annular magnetic steel is interference-connected with a sheath.

[0016] The present invention also provides a magnetic levitation motor, comprising the above-mentioned motor rotor.

[0017] The present invention provides a motor rotor and a magnetic levitation motor, in which the first rotating shaft and the second rotating shaft are pinned together by the first pin so that the two form a whole, thereby improving the structural strength and rigidity of the motor rotor. At this time, the interference force between the sleeve mounted on the outer peripheral side of the magnetic steel and the magnetic steel can be greatly reduced, that is, the heating temperature of the sleeve can be reduced to a very low level, thereby achieving extremely small deformation of the sleeve after the interference fit is cooled, effectively preventing the occurrence of a gap between the sleeve and the adjacent shaft end retaining ring in the prior art, reducing the difficulty of the assembly process while effectively preventing stress concentration at the corner of the gap on the rotating shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the internal structure of a motor rotor in the prior art;

[0019] Figure 2 This is a schematic diagram of the internal structure of a motor rotor according to an embodiment of the present invention, in which the arrows on the motor rotor and the bearing rotor indicate an electromagnetic flux loop;

[0020] Figure 3 for Figure 2 Schematic diagram of the three-dimensional structure (partial cross-section);

[0021] Figure 4 for Figure 2 A schematic diagram of the three-dimensional structure of the first rotating shaft;

[0022] Figure 5 for Figure 2A schematic diagram of the cross-sectional structure of the first rotating shaft or the second rotating shaft.

[0023] The reference numerals indicate:

[0024] 1. First rotating shaft; 11. First protrusion; 111. First magnetic steel fitting section; 112. First pin-connected inserting section; 12. Second groove; 121. First pin hole; 13. First shaft extension; 14. First shaft end retaining ring; 15. First pin retaining ring; 16. First bearing rotor lamination; 17. First bearing rotor retaining ring; 2. Second rotating shaft; 21. First groove; 211. Second pin hole; 22. Second protrusion; 221. Second magnetic steel fitting section; 222. Second pin-connected inserting section; 23. Second shaft extension; 24. Second shaft end retaining ring; 25. Second pin retaining ring; 26. Second bearing rotor lamination; 27. Second bearing rotor retaining ring; 31. First pin; 32. Second pin; 4. Annular magnetic steel; 5. Sleeve. DETAILED DESCRIPTION

[0025] See also Figures 2 to 5 As shown, according to an embodiment of the present invention, a motor rotor is provided, including a first rotating shaft 1 and a second rotating shaft 2, the first rotating shaft 1 and the second rotating shaft 2 are coaxial, the first rotating shaft 1 has a first protrusion 11 extending along its axial direction, the second rotating shaft 2 has a first groove 21 extending along its axial direction, the first protrusion 11 is at least partially inserted into the first groove 21, and the first protrusion 11 and the groove wall of the first groove 21 are pinned together by a first pin 31. It can be understood that the first protrusion 11 will at least partially serve as a mounting carrier for the magnetic steel, and the outer peripheral side of the magnetic steel is covered with a sheath 5 to apply a force to the magnetic steel toward the axial direction of the first rotating shaft 1 and the second rotating shaft 2. In this technical solution, the first rotating shaft 1 and the second rotating shaft 2 are pinned together by the first pin 31 so that the two form a whole, thereby improving the structural strength and rigidity of the motor rotor. At this time, the interference force between the sleeve 5 mounted on the outer peripheral side of the magnetic steel and the magnetic steel can be greatly reduced, that is, the heating temperature of the sleeve 5 can be reduced to a very low level (usually can be reduced to within 100°C). In this way, the deformation of the sleeve 5 after the interference fit is cooled is extremely small, effectively preventing the occurrence of a gap between the sleeve and the adjacent shaft end retaining ring in the prior art, reducing the difficulty of the assembly process while effectively preventing the occurrence of stress concentration at the corner of the gap on the rotating shaft.

[0026] In some embodiments, the first rotating shaft 1 further has a second groove 12 extending along its axial direction, and the second rotating shaft 2 further has a second protrusion 22 extending along its axial direction. The second protrusion 22 is at least partially inserted into the second groove 12, and the second protrusion 22 is pinned to the groove wall of the second groove 12 via a second pin 32. In this technical solution, the first protrusion 11 and the first groove 21, and the second protrusion 22 and the second groove 12 achieve interlocking of the first rotating shaft 1 and the second rotating shaft 2, while the second pin 32 and the first pin 31, respectively located on the first rotating shaft 1 and the second rotating shaft 2, form a balance of connection force points between the two, thereby improving the connection reliability between the first rotating shaft 1 and the second rotating shaft 2, and further enhancing the structural strength and rigidity of the motor rotor.

[0027] In some embodiments, the first rotating shaft 1 also includes a first shaft extension body 13, the first protrusion 11 is located at one axial end of the first shaft extension body 13, the first protrusion 11 includes a first magnetic steel sleeve segment 111 and a first pin-connected plug-in segment 112 located on the side of the first magnetic steel sleeve segment 111 away from the first shaft extension body 13; the second rotating shaft 2 also includes a second shaft extension body 23, the second protrusion 22 is located at one axial end of the second shaft extension body 23, the second protrusion 22 includes a second magnetic steel sleeve segment 221 and a second pin-connected plug-in segment 222 located on the side of the second magnetic steel sleeve segment 221 away from the second shaft extension body 23. Furthermore, any plane perpendicular to the axial direction of the first rotating shaft 1 is a first plane, and the projection of the first magnetic steel set segment 111 on the first plane is a semicircle, and / or the projection of the first pin-connected plug-in segment 112 on the first plane is a rectangle; any plane perpendicular to the axial direction of the second rotating shaft 2 is a second plane, and the projection of the second magnetic steel set segment 221 on the second plane is a semicircle, and / or the projection of the second pin-connected plug-in segment 222 on the second plane is a rectangle. Thus, the projections of both the first magnetic steel set segment 111 and the second magnetic steel set segment 221 are semicircular, and when interlocked, they form a cylinder, which then constitutes the mounting surface of the magnetic steel. It is understandable that the first rotating shaft 1 and the second rotating shaft 2 can be designed to be exactly the same in terms of specific structure, and their interlocking assembly can be achieved by simply changing the assembly angle during assembly, thereby simplifying the processing difficulty of the first rotating shaft 1 and the second rotating shaft 2.

[0028] Preferably, on the first plane, the projection of the first pin-jointed insert section 112 is within the projection of the first magnetic steel sheathing section 111; and / or, on the second plane, the projection of the second pin-jointed insert section 222 is within the projection of the second magnetic steel sheathing section 221. In other words, the first pin-jointed insert section 112 and the second pin-jointed insert section 222 are smaller than the corresponding first magnetic steel sheathing section 111 and second magnetic steel sheathing section 221. This allows the corresponding first groove 21 and second groove 12 to have smaller dimensions, thereby enabling the outer diameters of the first and second shaft extensions 13 and 23 to be designed to be smaller, making the overall structure of the motor rotor more compact and facilitating miniaturization of the motor.

[0029] Preferably, the connection between the first shaft extension body 13 and the first protrusion 11 comprises a first shaft end retaining ring 14, the second groove 12 extends from the first protrusion 11 toward the first shaft extension body 13, and the first pin hole 121 constructed on the groove wall of the second groove 12 is located on the side of the first shaft end retaining ring 14 away from the first protrusion 11; and / or, the connection between the second shaft extension body 23 and the second protrusion 22 comprises a second shaft end retaining ring 24, the first groove 21 extends from the second protrusion 22 toward the second shaft extension body 23, and the second pin hole 211 constructed on the groove wall of the first groove 21 is located on the side of the second shaft end retaining ring 24 away from the second protrusion 22. In this technical solution, the first pin hole 121 and the second pin hole 211 are respectively constructed on the first shaft extension body 13 and the second shaft extension body 23, which facilitates the pinned assembly process of the pin.

[0030] Preferably, the first shaft extension body 13 is provided with a first pin stop ring 15, and the fitting position of the first pin stop ring 15 is adapted to the first pin hole 121; and / or, the second shaft extension body 23 is provided with a second pin stop ring 25, and the fitting position of the second pin stop ring 25 is adapted to the second pin hole 211, thereby preventing the pins on the motor rotor from falling out during high-speed rotation.

[0031] Furthermore, the first shaft extension 13 is further fitted with a first bearing rotor lamination 16, which is located on the side of the first pin retaining ring 15 away from the first protrusion 11. And / or, the second shaft extension 23 is further fitted with a second bearing rotor lamination 26, which is located on the side of the second pin retaining ring 25 away from the second protrusion 22. In this case, the first and second pin retaining rings 15, 25 can also respectively position one axial end of the first and second bearing rotor laminations 16, 26. The first and second pin retaining rings 15, 25 should be made of non-magnetic materials.

[0032] Preferably, the first axial extension body 13 is also provided with a first bearing rotor retaining ring 17, which is located on the side of the first bearing rotor lamination 16 away from the first protrusion 11; and / or, the second axial extension body 23 is also provided with a second bearing rotor retaining ring 27, which is located on the side of the second bearing rotor lamination 26 away from the second protrusion 22, so as to ensure the position reliability of the corresponding bearing rotor laminations.

[0033] In some embodiments, the magnetic steel is an annular magnetic steel 4, which is mounted on the outer peripheral sides of the first protrusion 11 and the second protrusion 22 between the first shaft end retaining ring 14 and the second shaft end retaining ring 24, and the outer peripheral side of the annular magnetic steel 4 is interference-connected with a sheath 5.

[0034] The first rotating shaft 1 and the second rotating shaft 2 are made of non-magnetic material (such as SUS304), and the sheath 5 is preferably made of high-strength alloy sheath or high-strength carbon fiber and other high-strength materials to protect the magnetic steel during high-speed rotation.

[0035] The motor rotor of the present invention can be assembled in the following manner: the first pin retaining ring 15, the first bearing rotor lamination 16, and the first bearing rotor retaining ring 17 are stacked into a whole by a tool to form a first bearing rotor assembly; the second pin retaining ring 25, the second bearing rotor lamination 26, and the second bearing rotor retaining ring 27 are stacked into a whole by a tool to form a second bearing rotor assembly; the annular magnetic steel 4 is bonded to the first magnetic steel sleeve section 111 in the first rotating shaft 1 by structural adhesive, the jacket 5 is heated (controlled within 100°C to ensure a small interference fit), and then hot-fitted onto the annular magnetic steel 4, before the sleeve 5 is cooled, the second magnetic steel sleeve section 221 of the second shaft 2 is assembled into the inside of the annular magnetic steel 4 through tooling, and the second pin-connected plug-in section 222 is inserted into the second groove 12. After the pin holes are aligned, the pins are driven in to fix the positions of the first shaft 1 and the second shaft 2, so that the first shaft 1, the second shaft 2, the annular magnetic steel 4 and the sleeve 5 form a whole. Then, the first bearing rotor assembly and the second bearing rotor assembly formed in the previous sequence are heated to a suitable temperature, and then hot-fitted to the bearing rotor position to block the pin holes, and finally a new magnetic bearing high-speed motor rotor is formed.

[0036] According to an embodiment of the present invention, a magnetic levitation motor is further provided, comprising the above-mentioned motor rotor.

[0037] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A motor rotor, characterized in that: The invention comprises a first rotating shaft (1) and a second rotating shaft (2), wherein the first rotating shaft (1) and the second rotating shaft (2) are coaxial, the first rotating shaft (1) has a first protrusion (11) extending along its axial direction, the second rotating shaft (2) has a first groove (21) extending along its axial direction, the first protrusion (11) is at least partially inserted into the first groove (21), and the first protrusion (11) and the groove wall of the first groove (21) are pin-connected by a first pin (31); the first rotating shaft (1) also has a first protrusion (11) extending along its axial direction, The second rotating shaft (2) further comprises a second protrusion (22) extending in the axial direction thereof, wherein the second protrusion (22) is at least partially inserted into the second groove (12), and the second protrusion (22) is pin-connected to the groove wall of the second groove (12) via a second pin (32); the first rotating shaft (1) further comprises a first shaft extension (13), the first protrusion (11) is located at one axial end of the first shaft extension (13), and the first protrusion (11) comprises a first protrusion (32) The invention relates to a magnetic steel sleeve section (111) and a first pin-connected plug-in section (112) located on the side of the first magnetic steel sleeve section (111) away from the first shaft extension body (13); the second rotating shaft (2) also includes a second shaft extension body (23), the second protrusion (22) is located at one axial end of the second shaft extension body (23), the second protrusion (22) includes a second magnetic steel sleeve section (221) and a second pin-connected plug-in section (222) located on the side of the second magnetic steel sleeve section (221) away from the second shaft extension body (23). ); any plane perpendicular to the axial direction of the first rotating shaft (1) is a first plane, the projection of the first magnetic steel set section (111) on the first plane is a semicircle, and / or the projection of the first pin-connected plug-in section (112) on the first plane is a rectangle; any plane perpendicular to the axial direction of the second rotating shaft (2) is a second plane, the projection of the second magnetic steel set section (221) on the second plane is a semicircle, and / or the projection of the second pin-connected plug-in section (222) on the second plane is a rectangle.

2. The motor rotor according to claim 1, characterized in that: On the first plane, the projection of the first pin-connected plug-in section (112) is within the projection range of the first magnetic steel sleeve section (111); and / or, on the second plane, the projection of the second pin-connected plug-in section (222) is within the projection range of the second magnetic steel sleeve section (221).

3. The motor rotor according to claim 1, characterized in that: The connection between the first shaft extension body (13) and the first protrusion (11) comprises a first shaft end retaining ring (14), the second groove (12) extends from the first protrusion (11) toward one side of the first shaft extension body (13), and the first pin hole (121) constructed on the groove wall of the second groove (12) is located on the side of the first shaft end retaining ring (14) away from the first protrusion (11); and / or the connection between the second shaft extension body (23) and the second protrusion (22) comprises a second shaft end retaining ring (24), the first groove (21) extends from the second protrusion (22) toward one side of the second shaft extension body (23), and the second pin hole (211) constructed on the groove wall of the first groove (21) is located on the side of the second shaft end retaining ring (24) away from the second protrusion (22).

4. The motor rotor according to claim 3, characterized in that: A first pin retaining ring (15) is sleeved on the first shaft extension body (13), and the sleeve position of the first pin retaining ring (15) is adapted to the first pin hole (121); And / or, a second pin retaining ring (25) is sleeved on the second shaft extension body (23), and the sleeve position of the second pin retaining ring (25) is adapted to the second pin hole (211).

5. The motor rotor according to claim 4, characterized in that: The first shaft extension body (13) is also provided with a first bearing rotor lamination (16), and the first bearing rotor lamination (16) is located on the side of the first pin retaining ring (15) away from the first protrusion (11); and / or the second shaft extension body (23) is also provided with a second bearing rotor lamination (26), and the second bearing rotor lamination (26) is located on the side of the second pin retaining ring (25) away from the second protrusion (22).

6. The motor rotor according to claim 5, characterized in that: The first shaft extension body (13) is also provided with a first bearing rotor retaining ring (17), and the first bearing rotor retaining ring (17) is located on the side of the first bearing rotor lamination (16) away from the first protrusion (11); and / or the second shaft extension body (23) is also provided with a second bearing rotor retaining ring (27), and the second bearing rotor retaining ring (27) is located on the side of the second bearing rotor lamination (26) away from the second protrusion (22).

7. The motor rotor according to claim 3, characterized in that: The outer circumference of the first protrusion (11) and the second protrusion (22) between the first shaft end retaining ring (14) and the second shaft end retaining ring (24) is sheathed with an annular magnetic steel (4), and the outer circumference of the annular magnetic steel (4) is interference-connected with a sheath (5).

8. A magnetic levitation motor, comprising a motor rotor, characterized in that: The motor rotor is the motor rotor according to any one of claims 1 to 7.

Images