A magnetic levitation high-speed asynchronous motor

Abstract

The present invention relates to the field of magnetic levitation motors, and particularly to a high-speed magnetic levitation asynchronous motor. The motor includes a housing, a stator, a motor shaft, a radial bearing, and an axial bearing; the motor shaft includes a first shaft section, two second shaft sections respectively located outside both ends of the first shaft section, and two third shaft sections respectively located outside both ends of the second shaft sections; a permanent magnet is arranged inside the first shaft section, a copper-clad layer is arranged on the surface of the first shaft section, and the first shaft section is connected to the driving end of the stator; the second shaft section and the third shaft section are respectively connected to the supporting end of the axial bearing and the supporting end of the radial bearing. By arranging a copper-clad layer on the surface of the rotor, the motor does not need to be provided with a sheath, thereby improving the rotational speed and power of the high-speed motor and the heat dissipation performance of the motor.

Description

Technical Field

[0001] The present invention relates to the field of magnetic levitation motors, and particularly to a magnetic levitation high-speed asynchronous motor. 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 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 expanding continuously. During the operation of a magnetic levitation motor, the stability of the motor rotor is the key to ensuring the smooth 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] Chinese Patent Application for Invention (Publication No. CN108988534B, Publication Date: 20200619) discloses a high-speed permanent magnet motor rotor and its processing method, including a rotating shaft, which from left to right includes a first shaft body, a second shaft body and a third shaft body. Magnetically levitated bearing sensor rotor assembly, magnetically levitated bearing sensor rotor silicon steel sheet, magnetically levitated bearing rotor assembly and magnetically levitated bearing rotor silicon steel sheet are hot-sleeved and tightly fitted on both the first shaft body and the third shaft body. A rotor core is sleeved on the second shaft body, and surface-mounted permanent magnets are arranged on the outer periphery of the rotor core, and a carbon fiber protective sleeve is coated on the outer periphery of the permanent magnets. The overall structure of the rotor of the present invention is tight and reliable; it has strong resistance to radial tension and tangential stress; it effectively protects the permanent magnets in the permanent magnet motor; it has strong heat dissipation ability; the processing method of the present invention can reasonably and efficiently realize the processing of high-quality high-speed permanent magnet motor rotors through the close cooperation between different steps.

[0004] The prior art has the following deficiencies: Traditional high-speed motors are permanent magnet motors, and the outer surface of the magnetic steel requires a protective sleeve, which is limited by mechanical properties in a high-speed and high-power shafting. The materials of the protective sleeve generally use carbon fiber and nickel-based alloy, and their thermal conductivity is average. It is difficult to conduct the working temperature of the magnetic steel inside the protective sleeve, reducing the service life of the magnetic steel. Summary of the Invention

[0005] The purpose of the present invention is: In view of the above problems, a copper-clad rotor of a magnetic levitation high-speed asynchronous motor is proposed, which improves the rotational speed and power of the high-speed motor and the heat dissipation performance of the motor by setting a copper-clad layer on the rotor surface without the need to set a protective sleeve.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A magnetic levitation high-speed asynchronous motor, which includes a motor housing, a stator, a motor shaft, a radial bearing and an axial bearing; the motor shaft includes a first shaft section, two second shaft sections respectively located outside both ends of the first shaft section, and two third shaft sections respectively located outside both ends of the second shaft sections; a permanent magnet is arranged inside the first shaft section, a copper-clad layer is arranged on the surface of the first shaft section, and the first shaft section is connected to the driving end of the stator; the second shaft section and the third shaft section are respectively connected to the supporting end of the axial bearing and the supporting end of the radial bearing.

[0008] Preferably, the two second shaft sections and the two third shaft sections are symmetrically distributed along the axial direction of the first shaft section.

[0009] Preferably, the copper-clad layer includes a concave part in the middle and convex parts on both sides, and the width of the concave part is the same as that of the driving end of the stator.

[0010] Preferably, the cylinder diameter of the second shaft section is smaller than that of the first shaft section, and a first shaft shoulder is formed on the outer end face of the first shaft section at the connection position between the second shaft section and the first shaft section; the cylinder diameter of the third shaft section is smaller than that of the second shaft section, and a second shaft shoulder is formed on the outer end face of the second shaft section at the connection position between the third shaft section and the second shaft section; both the first shaft shoulder and the second shaft shoulder are magnetic conductive surfaces, and the first shaft shoulder and the second shaft shoulder are respectively connected to the stator magnetic circuit supporting ends of the axial bearing.

[0011] Preferably, the second shaft section and the third shaft section are connected by a bevel transition.

[0012] Preferably, a radial magnetic bearing rotor assembly is arranged on the outer surface of the third shaft section, and the radial magnetic bearing rotor assembly is connected to the magnetic circuit supporting end of the radial bearing.

[0013] Preferably, the motor shaft further includes a fourth shaft section, and the two fourth shaft sections are respectively located outside the two third shaft sections; punching sheets that are axially stacked and adhered to each other are shrink-fitted on the outer surface of the fourth shaft section, and the punching sheets on the fourth shaft section are connected to the sensing ends of the axial sensors.

[0014] Preferably, the motor shaft further includes a fifth shaft section, and the two fifth shaft sections are respectively located outside the two fourth shaft sections, and the outer surface of the fifth shaft section is matched with the inner ring of the non-magnetic radial bearing.

[0015] Preferably, end teeth are arranged on the outer cylindrical surface of the fifth shaft section, and the end teeth are matched with the connection part of the impeller.

[0016] Preferably, screw holes are arranged on the outer end face of the fifth shaft section, and the impeller is fixed on the screw holes and connected to the motor shaft.

[0017] The advantages of a magnetic levitation high-speed asynchronous motor adopting the above technical solution of the present invention are:

[0018] The copper-clad layer and the shaft are integrated, with excellent mechanical properties, greatly improving the limits of the rotational speed and power of high-speed motors. The thermal conductivity of copper is 10 times higher than that of carbon fiber and 6.5 times higher than that of nickel-based alloys, also greatly improving the heat dissipation of the motor. Brief Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the present invention.

[0020] Figure 2 It is a schematic structural diagram of the motor shaft.

[0021] Figure 3 It is a schematic structural diagram of the magnetic field circuit of the axial bearing.

[0022] Figure 4 It is a schematic structural diagram of the magnetic field circuit of the radial bearing.

[0023] Figure 5 It is a schematic structural diagram of the magnetic field of the stator and the copper-clad layer.

[0024] 11 - Front bearing housing, 12 - Rear bearing housing, 13 - Sensor, 14 - Protective bearing, 51 - Radial bearing stator, 52 - Radial bearing rotor. Detailed Description of the Invention

[0025] The following will describe in detail the specific embodiments of the present invention with reference to the drawings.

[0026] Embodiment 1

[0027] Such as Figures 1-5 shown, a magnetic levitation high-speed asynchronous motor, which includes a motor housing 1, a stator 2, a motor shaft 3, a radial bearing 5, and an axial bearing 6; the motor shaft 3 includes a first shaft section 31, two second shaft sections 32 respectively located outside both ends of the first shaft section 31, and two third shaft sections 33 respectively located outside both ends of the second shaft sections 32; a permanent magnet is arranged inside the first shaft section 31, a copper-clad layer 34 is arranged on the surface of the first shaft section 31, and the first shaft section 31 is connected to the driving end of the stator 2; the second shaft sections 32 and the third shaft sections 33 are respectively connected to the supporting ends of the axial bearing 6 and the radial bearing 5. In this solution, the copper-clad layer 34 and the shaft are integrated, with excellent mechanical properties, greatly improving the limits of the rotational speed and power of high-speed motors. The thermal conductivity of copper is 10 times higher than that of carbon fiber and 6.5 times higher than that of nickel-based alloys, also greatly improving the heat dissipation of the motor.

[0028] The two second shaft sections 32 and the two third shaft sections 33 are both axially symmetrically distributed along the first shaft section 31. The copper-clad layer 34 includes a concave portion 35 located in the middle and convex portions 36 located on both sides, and the width of the concave portion 35 is the same as that of the driving end of the stator 2.

[0029] The diameter of the cylinder of the second shaft section 32 is smaller than that of the cylinder of the first shaft section 31. A first shaft shoulder 37 is formed on the outer end surface of the first shaft section 31 at the connection position between the second shaft section 32 and the first shaft section 31. The diameter of the cylinder of the third shaft section 33 is smaller than that of the cylinder of the second shaft section 32. A second shaft shoulder 38 is formed on the outer end surface of the second shaft section 32 at the connection position between the third shaft section 33 and the second shaft section 32. Both the first shaft shoulder 37 and the second shaft shoulder 38 are magnetically conductive surfaces, and the first shaft shoulder 37 and the second shaft shoulder 38 are respectively connected to the stator magnetic circuit support ends of the axial bearing 6. The magnetically conductive surfaces of the first shaft shoulder 37 and the second shaft shoulder 38 are grouped in pairs and maintain the axial position under the drive of the stator magnetic circuit of the axial bearing 6. Thus, the axial bearing 6 is made into a structure without a thrust disk, saving space and reducing the requirements for mechanical properties.

[0030] The second shaft section 32 and the third shaft section 33 are connected by a bevel transition to reduce the internal stress between different shaft sections.

[0031] A radial magnetic bearing rotor assembly is provided on the outer surface of the third shaft section 33. The radial magnetic bearing rotor assembly is connected to the magnetic circuit support end of the radial bearing 5. The radial magnetic bearing rotor assembly and the stator magnetic field of the radial magnetic bearing 5 form a loop to make the rotor levitate under magnetic force.

[0032] The motor shaft 3 further includes fourth shaft sections 39. The two fourth shaft sections 39 are respectively located outside the two third shaft sections 33. Laminations that are axially stacked and fitted are shrink-fitted on the outer surface of the fourth shaft section 39. And the laminations on the fourth shaft section 39 are connected to the induction end of the axial sensor to detect the axial position of the motor shaft 3.

[0033] The motor shaft 3 further includes fifth shaft sections 30. The two fifth shaft sections 30 are respectively located outside the two fourth shaft sections 39, and the outer surface of the fifth shaft section 30 is matched with the inner ring of the non-magnetic radial bearing. When the motor is powered off, the magnetic forces provided by the radial bearing 5 and the axial bearing 6 disappear, and the motor shaft 3 drops to the position of the non-magnetic radial bearing and is supported to prevent the motor shaft 3 from suddenly dropping and being damaged.

[0034] End face teeth 301 are provided on the cylindrical outer surface of the fifth shaft section 30. The end face teeth 301 are matched with the connection part of the impeller. The end face tooth structure 301 is automatically centered with the impeller to transmit torque. Screw holes are provided on the outer end face of the fifth shaft section 30, and the impeller is fixed on the screw holes and connected to the motor shaft 3.

Claims

1. A magnetic levitation high-speed asynchronous motor, which comprises a motor housing (1), a stator (2), a motor shaft (3), a radial bearing (5) and an axial bearing (6); characterized in that, The motor shaft (3) includes a first shaft section (31), two second shaft sections (32) respectively located outside both ends of the first shaft section (31), and two third shaft sections (33) respectively located outside both ends of the second shaft sections (32). The second shaft section (32) and the third shaft section (33) are transitionally connected by an inclined surface. A permanent magnet is arranged inside the first shaft section (31), a copper-clad layer (34) is arranged on the surface of the first shaft section (31), and the first shaft section (31) is connected to the driving end of the stator (2). The second shaft section (32) and the third shaft section (33) are respectively connected to the supporting end of the axial bearing (6) and the supporting end of the radial bearing (5). The copper-clad layer (34) includes a concave portion (35) located in the middle and convex portions (36) located on both sides. The width of the concave portion (35) is the same as that of the driving end of the stator (2). A radial magnetic bearing rotor assembly is arranged on the outer surface of the third shaft section (33), and the radial magnetic bearing rotor assembly is connected to the magnetic circuit supporting end of the radial bearing (5). The cylindrical diameter of the second shaft section (32) is smaller than that of the first shaft section (31), and a first shaft shoulder (37) is formed on the outer end surface of the first shaft section (31) at the connection position between the second shaft section (32) and the first shaft section (31). The cylindrical diameter of the third shaft section (33) is smaller than that of the second shaft section (32), and a second shaft shoulder (38) is formed on the outer end surface of the second shaft section (32) at the connection position between the third shaft section (33) and the second shaft section (32). Both the first shaft shoulder (37) and the second shaft shoulder (38) are magnetic conductive surfaces, and the first shaft shoulder (37) and the second shaft shoulder (38) are respectively connected to the stator magnetic circuit supporting end of the axial bearing (6). The motor shaft (3) further includes a fourth shaft section (39), and the two fourth shaft sections (39) are respectively located outside the two third shaft sections (33). Laminations axially stacked and fitted to each other are shrink-fitted on the outer surface of the fourth shaft section (39), and the laminations on the fourth shaft section (39) are connected to the sensing end of the axial sensor. The motor shaft (3) further includes a fifth shaft section (30), and the two fifth shaft sections (30) are respectively located outside the two fourth shaft sections (39), and the outer surface of the fifth shaft section (30) is matched with the inner ring of the non-magnetic radial bearing.

2. The maglev high-speed asynchronous motor according to claim 1, wherein The two second shaft sections (32) and the two third shaft sections (33) are axially symmetrically distributed along the first shaft section (31).

3. The magnetic levitation high-speed asynchronous motor according to claim 1, wherein End teeth (301) are arranged on the cylindrical outer surface of the fifth shaft section (30), and the end teeth (301) are matched with the connection part of the impeller.

4. The magnetic levitation high-speed asynchronous motor according to claim 1, wherein Screw holes are arranged on the outer end surface of the fifth shaft section (30), and the impeller is fixed on the screw holes and connected to the motor shaft (3).

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