A Method for Installing Surface-Mounted Permanent Magnets on a Maglev Rotor

Abstract

The present invention relates to the field of magnetic levitation motor shafts, and particularly to a method for installing surface-mounted permanent magnets on a magnetic levitation rotor. The magnetic levitation rotor includes a core shaft, permanent magnets, a magnetic isolation ring, a sheath, a hot sleeve assembly, and a thrust disk; the core shaft is provided with a limiting block and a limiting ring of an integral structure, and the core shaft is divided into a left end, a right end, and a middle end; the magnetic isolation ring and the permanent magnets are both axially arranged on the middle end of the core shaft, and the outer ring surface formed by the combination of the permanent magnets and the magnetic isolation ring is flush with the outer ring surfaces of the limiting block and the limiting ring; the sheath is sleeved on the outer ring surface of the permanent magnets, and both ends of the sheath are respectively attached to the limiting block and the limiting ring; the thrust disk is arranged at the left end of the core shaft and abuts against the left end of the limiting block; two groups of hot sleeve assemblies are respectively sleeved on the left end and the right end of the core shaft, the hot sleeve assembly at the left end abuts against the thrust disk, and the hot sleeve assembly at the right end abuts against the limiting ring. This device can effectively improve the rigidity of the motor shaft, thereby ensuring that the accuracy of the motor shaft is not affected by centrifugal force.

Description

Technical Field

[0001] The present invention relates to the field of magnetic levitation motor shafts, and particularly to a method for installing surface-mounted permanent magnets on a magnetic levitation rotor. Background Art

[0002] With the development of science and technology and the demands of production, magnetic levitation high-speed motors have become one of the research hotspots in the international electrical engineering field. Due to the advantages of high energy density, small structural size, high efficiency, etc., magnetic levitation high-speed motors have currently been widely used in industrial fields such as micro gas turbines, high-speed centrifugal compressors, molecular pumps, high-speed machining centers, flywheel energy storage, etc., and their application scope is still continuously expanding. During the operation of a magnetic levitation motor, the stability of the motor rotor is the key to ensuring the stable and efficient operation of the motor. The magnetic properties of the permanent magnets of the motor rotor and the dynamic balance of the rotor itself directly affect the working performance of the magnetic levitation motor.

[0003] A positioning tooling for a magnetic levitation motor shaft, a motor shaft, an assembly tooling, a rotor, and a sheath tooling disclosed in a Chinese utility model patent (Publication No.: CN215871119U; Publication Date: February 18, 2022) includes permanent magnets, magnetic isolation rings, a front main shaft, and a rear main shaft; multiple permanent magnets are stacked and distributed along the axial direction, and adjacent two permanent magnets are fixedly connected by glue. Since its motor shaft is composed of these four components, namely permanent magnets, magnetic isolation rings, a front main shaft, and a rear main shaft, a large amount of centrifugal force will be generated during the operation of the device, which will cause the components of the motor shaft to shift, thereby affecting the accuracy of the motor shaft. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a method for installing surface-mounted permanent magnets on a magnetic levitation rotor. This device method can well improve the rigidity of the motor shaft, thereby ensuring that the accuracy of the motor shaft is not affected by centrifugal force, can also save a large amount of time, and reduce the economic cost of machine operation during processing.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A method for installing surface-mounted permanent magnets on a magnetic levitation rotor. This method installs surface-mounted permanent magnets on the magnetic levitation rotor. The magnetic levitation rotor includes a core shaft, permanent magnets, two magnetic isolation rings, a sheath, a shrink-fit assembly, and a thrust disk. An integrally structured first limiting ring and a second limiting ring are provided on the core shaft. An annular groove is formed between the first limiting ring and the second limiting ring on the core shaft. The two magnetic isolation rings and the permanent magnets are all axially sleeved in the annular groove. The outer ring surface formed by the combination of the permanent magnets and the magnetic isolation rings is flush with the outer ring surface of the annular groove. The inner rings of the magnetic isolation rings and the permanent magnets are adhesively bonded to the annular groove respectively. The two magnetic isolation rings are arranged on both sides of the permanent magnets and are adhesively bonded to the permanent magnets respectively. The permanent magnets are composed of multiple groups of magnetic components adhesively bonded to each other. Each group of magnetic components is evenly adhesively bonded in the annular groove. The two magnetic isolation rings are formed by adhesively bonding two semi-circular half magnetic isolation rings. The sheath is sleeved on the outer ring surface of the annular groove. The two ends of the sheath are respectively attached to the first limiting ring and the second limiting ring. The thrust disk is arranged at the left end of the core shaft and abuts against the left end of the first limiting ring. The shrink-fit assembly has two groups respectively sleeved on the left end and the right end of the core shaft. The shrink-fit assembly at the left end abuts against the thrust disk, and the shrink-fit assembly at the right end abuts against the second limiting ring. The method includes the following steps:

[0007] (S1)Fix the two ends of the core shaft on a grinding machine to enable the grinding machine to process the core shaft. Among them, precisely process the middle part of the core shaft to form an annular groove, and leave a small amount of allowance for the left end, right end, first limiting ring part, and second limiting ring part of the core shaft except the middle part for subsequent processing;

[0008] (S2)Process the left end of the first limiting ring so that its left end presents a shape with two steps;

[0009] (S3)Sequentially surface-mount magnetic isolation rings, permanent magnets, and magnetic isolation rings on the middle part of the core shaft. Use glue to fix the magnetic isolation rings and the permanent magnets on the core shaft, and use a hose clamp to tie the surfaces of the permanent magnets and the magnetic isolation rings;

[0010] (S4)After the glue cures, remove the hose clamp, and then use a grinding machine to grind and process the parts of the core shaft except the middle part and the outer surface of the permanent magnets;

[0011] (S5)Set a limiting tooling on the first limiting ring, and set a transition guiding tooling that abuts against it at the right end of the second limiting ring;

[0012] (S6)After heating the sheath, axially insert it into the core shaft from the end where the transition guiding tooling is set, and make the end face of the sheath abut against the limiting tooling;

[0013] (S7) Remove the limit tooling and the transition guiding tooling, heat a set of thrust discs and two sets of shrink-fit components. First, sleeve the thrust disc on the step of the first limit ring, then sequentially sleeve the shrink-fit components on the left and right ends of the mandrel, and one of the sets abuts against the thrust disc, with a gap provided between the thrust disc and the sheath;

[0014] (S8)The shrink-fit component at the left end not only abuts against the thrust disc but also leaves a gap with the first limit ring;

[0015] (S9)Axially arranged central holes are provided in the middle of the left and right ends of the mandrel. By clamping the central holes of the mandrel, the outer ring surfaces at its left and right ends are machined to remove the excess dimensions.

[0016] Preferably, the left end of the first limit ring is stepped, the thrust disc is arranged at the step of the first limit ring, and the shrink-fit component abuts against the thrust disc.

[0017] Preferably, the size of the gap is 0.2 mm - 0.5 mm.

[0018] Preferably, the shape of the magnet assembly is a semi-circular ring. Multiple sets of magnet assemblies are adhered in the annular groove by glue, and two sets of assemblies are adhesively combined with each other to form a magnet.

[0019] Preferably, the size of the allowance is 0.2 mm - 0.8 mm.

[0020] In summary, the advantages of the present invention are as follows:

[0021] By integrally arranging the first limit ring and the second limit ring on the mandrel, and axially arranging the magnetic isolation ring and the magnet in the middle of the mandrel, the outer ring surface formed by the combination of the magnet and the magnetic isolation ring is flush with the outer ring surfaces of the first limit ring and the second limit ring. The magnetic isolation ring, the magnet and the mandrel are connected together by the sheath, improving the strength and stiffness of the motor shaft, thereby ensuring that the accuracy of the motor shaft will not be affected by the centrifugal force. This installation method has fewer processes, can save a large amount of time, and also reduces the economic cost of the machine operation during processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic cross-sectional view of the magnetic suspension rotor;

[0023] Figure 2 is a cross-sectional view of the mandrel;

[0024] Figure 3 is a schematic structural view of the mandrel, the magnet and the magnetic isolation ring;

[0025] Figure 4 is a schematic structural view of inserting into the sheath;

[0026] Figure 5 It is a structural schematic diagram of a limit tooling;

[0027] Figure 6 It is a structural schematic diagram of a transition guiding tooling;

[0028] Figure 7 It is a structural schematic diagram of a magnetic steel;

[0029] Figure 8 It is a partial sectional view of the gap between the hot sleeve assembly and the first limit ring;

[0030] Reference numerals: 1, mandrel; 2, magnetic steel; 3, magnetic isolation ring; 4, sheath; 5, hot sleeve assembly; 6, thrust disc; 7, limit tooling; 8, transition guiding tooling; 11, first limit ring; 12, second limit ring; 13, central hole; 21, gap; 22, void. Specific embodiments

[0031] The following will make a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

[0032] As Figures 1 to 8As shown, a method for installing surface-mounted permanent magnets on a magnetic levitation rotor. This method installs the magnetic levitation rotor, and the magnetic levitation rotor includes a core shaft 1, permanent magnets 2, two magnetic isolation rings 3, a sheath 4, a hot sleeve assembly 5, and a thrust disk 6. The core shaft 1 is provided with an integrally formed first limiting ring 11 and a second limiting ring 12, and the core shaft 1 is divided into a left end, a right end, and a middle end by the first limiting ring 11 and the second limiting ring 12. An annular groove is formed between the first limiting ring 11 and the second limiting ring 12 of the core shaft 1. The two magnetic isolation rings 3 and the permanent magnets 2 are all axially sleeved in the annular groove. The outer ring surface formed by the combination of the permanent magnets 2 and the magnetic isolation rings 3 is flush with the outer ring surface of the annular groove. The inner rings of the magnetic isolation rings 3 and the permanent magnets 2 are bonded to the annular groove respectively. The two magnetic isolation rings 3 are arranged on both sides of the permanent magnet 2 and are bonded to the permanent magnet 2 respectively. The permanent magnet 2 is composed of multiple groups of magnetic components bonded to each other. Each group of magnetic components is evenly bonded in the annular groove. The two magnetic isolation rings 3 are formed by bonding two semi-circular half magnetic isolation rings 3. The sheath 4 is sleeved on the outer ring surface of the annular groove, and both ends of the sheath 4 are respectively attached to the first limiting ring 11 and the second limiting ring 12. The thrust disk 6 is arranged at the left end of the core shaft 1 and abuts against the left end of the first limiting ring 11. The hot sleeve assembly 5 has two groups which are respectively sleeved on the left end and the right end of the core shaft 1. The hot sleeve assembly 5 at the left end abuts against the thrust disk 6, and the hot sleeve assembly 5 at the right end abuts against the second limiting ring 12. The left end of the first limiting ring 11 is stepped, the thrust disk 6 is arranged at the step of the first limiting ring 11, and the hot sleeve assembly 5 abuts against the thrust disk 6. The size of the gap 21 is 0.2 mm - 0.5 mm. The shape of the magnetic steel component is a semi-circular ring. Multiple groups of magnetic steel components are bonded in the annular groove by glue, and two groups of components are bonded to each other to form the permanent magnet 2. The size of the allowance is 0.2 mm - 0.8 mm.

[0033] As Figure 1 and Figure 2 shown, first, the first limiting ring 11 and the second limiting ring 12 are machined on the core shaft 1. By setting the first limiting ring 11 at the left end of the core shaft 1 and the first limiting ring 11 at the right end of the core shaft 1, the left end, the right end, and the middle end of the core shaft 1 are distinguished. Among them, the left side of the first limiting ring 11 is the left end of the core shaft 1, the right side of the second limiting ring 12 is the right end of the core shaft 1, and the depression in the middle of the first limiting ring 11 and the second limiting ring 12 is the middle end of the core shaft 1. By integrally setting the first limiting ring 11 and the second limiting ring 12 on the core shaft 1, the overall stiffness of the motor shaft can be enhanced.

[0034] As Figure 1 and Figure 3As shown in the figure, several magnetic steel 2 and two magnetic isolation rings 3 are provided on the middle end of the mandrel 1. During installation, the magnetic isolation rings 3, magnetic steel 2, and magnetic isolation rings 3 need to be installed in sequence. The two magnetic isolation rings 3 respectively abut against the first limiting ring 11 and the limiting plate, and clamp the magnetic steel 2 in the middle. The outer ring surface formed by the combination of the magnetic steel 2 and the magnetic isolation ring 3 is flush with the outer ring surfaces of the first limiting ring 11 and the second limiting ring 12, which is convenient for installing the sheath 4 later. Since the outer ring surfaces of these two are flush, it can ensure that the inner ring surface of the sheath 4 tightly adheres to the first limiting ring 11, the limiting plate, and the magnetic steel 2, achieving a good fixing effect. The sheath 4 is heated before installation, and then installed on the outer surface of the magnetic steel 2. Due to the effect of thermal expansion and contraction, the sheath 4 will shrink when it cools, so no other fixing is required, and a good fixing effect can also be achieved. The shape of the magnetic steel 2 is a semi-circular ring.

[0035] As Figure 4 shown, before installing the sheath 4, first install the limiting tooling 7 on the first limiting ring 11. A transition guiding tooling 8 that abuts against the first limiting ring 11 is installed on the right side of the first limiting ring 11. After both of these are installed, then axially install the transition guiding tooling 8 from the right side of the mandrel 1 where the mandrel 1 is located. The heated sheath 4 needs to pass through the transition guiding tooling 8, so that the overall accuracy of the mandrel 1 will not be affected. Since the sheath 4 is at a high temperature at this time, the material of the transition guiding tooling 8 is a high-hardness material with the property of being resistant to high temperature.

[0036] As Figure 1 and Figure 8 shown, one end of the installed sheath 4 is on the first limiting ring 11, and one end is on the second limiting ring 12 and wraps the magnetic steel 2 inside. At this time, the limiting tooling 7 and the transition guiding tooling 8 need to be removed. Then, a thrust disk 6 is passed through the step at the left end of the first limiting ring 11, and a hot sleeve assembly 5 is passed through the thrust disk 6 and abuts against the thrust disk 6. The hot sleeve assembly 5 is arranged on the left end of the mandrel 1, rather than on the first limiting ring 11. And when the hot sleeve assembly 5 abuts against the thrust disk 6, there is a gap 21 of 0.2 mm - 0.5 mm between the hot sleeve assembly 5 and the left end of the first limiting ring 11, in order to minimize the magnetization of the main shaft to the hot sleeve assembly 5. A set of hot sleeve assemblies 5 is also arranged on the right end of the mandrel 1 and abuts against the second limiting ring 12. Central holes 13 are provided at both the left and right ends of the mandrel 1, in order to be used as the positioning reference for the workpiece during processing and bear the self-weight and cutting force of the workpiece. Among them, there is a gap 22 between the sheath 4 and the thrust disk 6, and a tool can be used to perform runout correction on the entire device.

[0037] The installation method is as follows in sequence:

[0038] (S1)Fix both ends of the mandrel 1 on the grinding machine, and let the grinding machine process the mandrel 1. Among them, precisely process the middle part of the mandrel 1 to form an annular groove, and leave a small amount of allowance for the left end, right end, first limiting ring 11 part, and second limiting ring 12 part of the mandrel 1 except the middle part, which is convenient for subsequent processing;

[0039] (S3)On the left end of the first limiting ring 11, process it so that its left end presents a shape with two steps;

[0040] (S6)Attach a magnetic isolation ring 3, a magnetic steel 2, and a magnetic isolation ring 3 to the middle part of the mandrel 1 in sequence. Use glue to fix the magnetic isolation ring 3 and the magnetic steel 2 on the mandrel 1, and use a hose clamp to tie the surfaces of the magnetic steel 2 and the magnetic isolation ring 3;

[0041] (S9)After the glue cures, remove the hose clamp, and then use the grinding machine to grind and process the parts of the mandrel 1 except the middle part and the outer surface of the magnetic steel 2;

[0042] (S5)Set a limiting tooling 7 on the first limiting ring 11, and set a transition guiding tooling 8 that abuts against it on the right end of the second limiting ring 12;

[0043] (S15)After heating the sheath 4, axially insert it into the mandrel 1 from the end where the transition guiding tooling 8 is set, and make the end face of the sheath 4 abut against the limiting tooling 7;

[0044] (S18)Remove the limiting tooling 7 and the transition guiding tooling 8, heat a set of thrust disks 6 and two sets of hot sleeve assemblies 5. First, set the thrust disk 6 on the step of the first limiting ring 11, and then set the hot sleeve assemblies 5 on the left and right ends of the mandrel 1 in sequence, and one of them abuts against the thrust disk 6. There is a gap 22 between the thrust disk 6 and the sheath 4;

[0045] (S21)The hot sleeve assembly 5 at the left end not only abuts against the thrust disk 6 but also leaves a gap 21 between it and the first limiting ring 11;

[0046] (S24)Clamp the central hole 13 of the mandrel 1 and process the outer ring surfaces at its left and right ends to remove the excess dimensions.

[0047] The size of the allowance is 0.2 mm - 0.8 mm. Due to the addition of the allowance, the device can better determine the accuracy during processing, and there is no need for secondary processing due to accuracy changes, which also saves time.

[0048] The foregoing is a description of embodiments of the present invention. Through the above description of the disclosed embodiments, those skilled in the art can implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for installing surface-mounted permanent magnets on a magnetic levitation rotor, characterized in that This method installs the surface-mounted permanent magnets of a magnetic levitation rotor. The magnetic levitation rotor includes a core shaft (1), permanent magnets (2), two magnetic isolation rings (3), a sheath (4), a hot-fitting assembly (5), and a thrust disk (6). A first limiting ring (11) and a second limiting ring (12) with an integral structure are provided on the core shaft (1). An annular groove is formed between the first limiting ring (11) and the second limiting ring (12) on the core shaft (1). The two magnetic isolation rings (3) and the permanent magnets (2) are axially sleeved in the annular groove. The outer ring surface formed by the combination of the permanent magnets (2) and the magnetic isolation rings (3) is flush with the outer ring surface of the annular groove. The inner rings of the magnetic isolation rings (3) and the permanent magnets (2) are adhesively bonded to the annular groove. The two magnetic isolation rings (3) are arranged on both sides of the permanent magnets (2) and are adhesively bonded to the permanent magnets (2) respectively. The permanent magnets (2) are composed of multiple groups of magnetic components adhesively bonded to each other, and each group of magnetic components is evenly adhesively bonded in the annular groove. The two magnetic isolation rings (3) are formed by adhesively bonding two semi-circular half magnetic isolation rings (3). The sheath (4) is sleeved on the outer ring surface of the annular groove, and both ends of the sheath (4) are respectively attached to the first limiting ring (11) and the second limiting ring (12). The thrust disk (6) is arranged at the left end of the core shaft (1) and abuts against the left end of the first limiting ring (11). The hot-fitting assembly (5) has two groups respectively sleeved on the left end and the right end of the core shaft (1). The hot-fitting assembly (5) at the left end abuts against the thrust disk (6), and the hot-fitting assembly (5) at the right end abuts against the second limiting ring (12). This method includes the following steps: (S1) Fix both ends of the core shaft (1) on a grinding machine, and let the grinding machine process the core shaft (1). Among them, the middle part of the core shaft (1) is precisely processed to form an annular groove, and a small amount of allowance is left for the left end, right end, the part of the first limiting ring (11), and the part of the second limiting ring (12) of the core shaft (1) except the middle part for subsequent processing; (S2) Process the left end of the first limiting ring (11) to make its left end present a shape with two steps; (S3) Sequentially surface-mount the magnetic isolation rings (3), permanent magnets (2), and magnetic isolation rings (3) on the middle part of the core shaft (1). Use glue to fix the magnetic isolation rings (3) and the permanent magnets (2) on the core shaft (1), and use a hose clamp to tie the surfaces of the permanent magnets (2) and the magnetic isolation rings (3); (S4) After the glue cures, remove the hose clamp, and then immediately use a grinding machine to grind and process the parts of the core shaft (1) except the middle part and the outer surface of the permanent magnets (2); (S5) Set a limiting tooling (7) on the first limiting ring (11), and set a transition guiding tooling (8) that abuts against it at the right end of the second limiting ring (12); (S6) After heating the sheath (4), axially insert it into the core shaft (1) from the end where the transition guiding tooling (8) is set, and make the end face of the sheath (4) abut against the limiting tooling (7); (S7) Remove the limit tooling (7) and the transition guiding tooling (8), heat a set of thrust discs (6) and two sets of shrink-fit assemblies (5). First, set the thrust disc (6) on the step of the first limit ring (11), then sequentially set the shrink-fit assemblies (5) on the left and right ends of the mandrel (1), and one of the sets abuts against the thrust disc (6), and there is a gap (22) between the thrust disc (6) and the sheath (4); (S8) The shrink-fit assembly (5) at the left end not only abuts against the thrust disc (6), but also has a gap (21) with the first limit ring (11); (S9) Axially arranged central holes (13) are provided in the middle of the left and right ends of the mandrel (1). By clamping the central holes (13) of the mandrel (1), the outer ring surfaces at its left and right ends are machined to remove the excess dimensions.

2. The installation method of a surface-mounted permanent magnet for a magnetic levitation rotor according to claim 1, characterized in that The left end of the first limit ring (11) is stepped, the thrust disc (6) is arranged at the step of the first limit ring (11), and the shrink-fit assembly (5) abuts against the thrust disc (6).

3. The installation method of a surface-mounted permanent magnet of a magnetic levitation rotor according to claim 1, characterized in that The size of the gap (21) is 0.2 mm - 0.5 mm.

4. The installation method of a surface-mounted permanent magnet for a magnetic levitation rotor according to claim 1, characterized in that, The shape of the magnet assembly is a semi-circular ring. Multiple sets of magnet assemblies are adhered in the annular groove by glue, and two sets of assemblies are bonded to each other to form a magnet (2).

5. The installation method of a surface-mounted permanent magnet for a magnetic levitation rotor according to claim 1, characterized in that, The size of the allowance is 0.2 mm - 0.8 mm.

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