CN215682038U

CN215682038U - Magnetic suspension high-speed asynchronous motor without thrust disc

Info

Publication number: CN215682038U
Application number: CN202120982185.6U
Authority: CN
Inventors: 钟仁志; 袁军
Original assignee: Xinlei Compressor Co Ltd
Current assignee: Xinlei Compressor Co Ltd
Priority date: 2021-05-10
Filing date: 2021-05-10
Publication date: 2022-01-28
Anticipated expiration: 2031-05-10

Abstract

The utility model relates to the field of magnetic suspension motors, in particular to a magnetic suspension high-speed asynchronous motor without a thrust disc. The motor comprises a shell, a stator, a motor shaft, a radial bearing and an axial bearing; the motor shaft comprises a first shaft section, two second shaft sections respectively positioned at the outer sides of two ends of the first shaft section and two third shaft sections respectively positioned at the outer sides of two ends of the second shaft section; a first shaft shoulder is formed on the outer end face of the first shaft section at the connecting position of the second shaft section and the first shaft section; a second shaft shoulder is formed on the outer end face of the second shaft section at the connecting position of the third shaft section and the second shaft section; the first shaft shoulder and the second shaft shoulder are magnetic conductive surfaces, and are respectively connected with the stator magnetic circuit supporting end of the axial bearing. The motor respectively provides acting force for the magnetic guide surfaces arranged on the outer end surface of the first shaft section and the outer end surface of the second shaft section through the stator magnetic circuits of the axial bearings without arranging a thrust disc, the assembling step of the thrust disc is eliminated, the inner space of the motor is saved, and the cost of the whole motor is reduced.

Description

Magnetic suspension high-speed asynchronous motor without thrust disc

Technical Field

The utility model relates to the field of magnetic suspension motors, in particular to a magnetic suspension high-speed asynchronous motor without a thrust disc.

Background

With the development of science and technology and the demand of production, magnetic suspension high-speed motors have become one of the hot spots of international electrotechnical field research. Because the magnetic suspension high-speed motor has the advantages of high energy density, small structural size, high efficiency and the like, the magnetic suspension high-speed motor is widely applied to the industrial fields of micro gas turbines, high-speed centrifugal compressors, molecular pumps, high-speed processing centers, flywheel energy storage and the like at present, and the application range of the magnetic suspension high-speed motor is still continuously expanded. In the working process of the magnetic suspension motor, the stability of a motor rotor is the key for ensuring the stable and efficient operation of the motor. The magnetic property of the permanent magnet of the motor rotor and the dynamic balance of the rotor directly influence the working performance of the magnetic suspension motor.

The Chinese patent application (publication No. CN206035859U, published as 20170322) discloses a magnetic suspension bearing high-speed asynchronous motor direct-drive centrifugal compressor, which comprises a shell, wherein the shell is provided with an air inlet and an air outlet, an air compression impeller is arranged in the shell, the shell is fixedly connected with a motor connecting flange, the magnetic suspension bearing high-speed asynchronous motor also comprises a magnetic suspension bearing high-speed asynchronous motor, the magnetic suspension bearing high-speed asynchronous motor comprises a shell, a motor stator arranged on the shell, a motor rotor shaft matched with the motor stator and a magnetic suspension radial bearing matched with the motor rotor shaft, the shell is fixedly connected with the motor connecting flange, the motor rotor shaft is fixedly connected with the air compression impeller, the motor connecting flange is fixedly connected with a diffuser, and an auxiliary rolling bearing matched with the motor rotor shaft is fixed on the diffuser. The magnetic suspension radial bearing can realize high rotating speed and complete oil-free of the centrifugal compressor, and prolongs the service life of the magnetic suspension radial bearing.

The prior art has the following defects: the motor shaft is connected with the thrust disc, and a stator magnetic circuit of the axial bearing limits the axial position of the thrust disc so as to limit the axial position of the motor shaft; in the mode, a shaft shoulder of a motor shaft and a thermal sleeve clearance ring on the motor shaft are needed to limit the two sides of the thrust disc respectively and axially connect the thrust disc to the motor shaft, so that the assembling steps of the thrust disc are increased, and the required space in the motor is also increased; meanwhile, the thrust disc and the motor shaft are not integrated parts but two separated parts which need to be connected, and the strength of the thrust disc and the connection strength of the thrust disc and the motor shaft are required to meet the requirement of high mechanical property when the axial position of the motor shaft is limited by the thrust disc, so that the cost of the whole motor is increased.

Disclosure of Invention

The purpose of the utility model is: aiming at the problems, the magnetic suspension high-speed asynchronous motor without the thrust disc is provided, wherein the stator magnetic circuit of the axial bearing is used for respectively providing acting force for the magnetic guide surfaces arranged on the outer end surface of the first shaft section and the outer end surface of the second shaft section without the thrust disc, the assembling step of the thrust disc is eliminated, the internal space of the motor is saved, and the cost of the whole motor is reduced.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a magnetic suspension high-speed asynchronous motor without a thrust disc comprises a shell, a stator, a motor shaft, a radial bearing and an axial bearing; the motor shaft comprises a first shaft section, two second shaft sections respectively positioned at the outer sides of two ends of the first shaft section and two third shaft sections respectively positioned at the outer sides of two ends of the second shaft section; the diameter of the second shaft section cylinder is smaller than that of the first shaft section cylinder, and a first shaft shoulder is formed on the outer end face of the first shaft section at the connecting position of the second shaft section and the first shaft section; the diameter of the third shaft section cylinder is smaller than that of the second shaft section cylinder, and a second shaft shoulder is formed on the outer end face of the second shaft section at the connecting position of the third shaft section and the second shaft section; the first shaft shoulder and the second shaft shoulder are magnetic conductive surfaces, and are respectively connected with the stator magnetic circuit supporting end of the axial bearing.

Preferably, the two second shaft segments and the two third shaft segments are both axially symmetrically distributed along the first shaft segment.

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

Preferably, the first shaft section is internally provided with a permanent magnet, the surface of the first shaft section is provided with a copper-clad layer, and the first shaft section is connected with the driving end of the stator; the second shaft section and the third shaft section are respectively connected with the axial bearing supporting end and the radial bearing supporting end.

Preferably, the copper-clad layer comprises a concave part in the middle and convex parts on two sides, and the width of the concave part is the same as that of the driving end of the stator.

Preferably, the outer surface of the third shaft section is provided with a radial magnetic bearing rotor assembly, and the radial magnetic bearing rotor assembly is connected with the magnetic circuit supporting end of the radial bearing.

Preferably, the motor shaft further comprises fourth shaft sections, and the two fourth shaft sections are respectively positioned at the outer sides of the two third shaft sections; the outer surface of the fourth shaft section is sleeved with punching sheets which are mutually stacked and attached in the axial direction, and the punching sheets on the fourth shaft section are connected with the induction end of the axial sensor.

Preferably, the motor shaft further comprises a fifth shaft section, the two fifth shaft sections are located on the outer sides of the two fourth shaft sections respectively, and the outer surface of each fifth shaft section is matched with the inner ring of the non-magnetic radial bearing.

Preferably, the outer surface of the cylinder of the fifth shaft section is provided with a face tooth, and the face tooth is matched with the connection part of the impeller.

Preferably, the end face of the outer side of the fifth shaft section is provided with a screw hole, and the impeller is fixed on the screw hole and connected with the motor shaft.

The magnetic suspension high-speed asynchronous motor adopting the technical scheme has the advantages that:

the magnetic conduction surfaces of the first shaft shoulder and the second shaft shoulder are grouped in pairs, and the axial position is kept under the driving of a stator magnetic circuit of the axial bearing; therefore, the axial bearing is made into a structure without a thrust disc, the thrust disc does not need to be assembled, and the space of the motor is saved. Meanwhile, a stator magnetic circuit of the axial bearing directly provides acting force for the motor shaft, and the mechanical property of the motor shaft is enough to meet the limit requirement; the additional higher mechanical property requirement on the strength of the thrust disc and the connection strength of the thrust disc and a motor shaft is not needed when the thrust disc is not acted, so that the cost of the whole device is reduced.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic view of the structure of the motor shaft.

Fig. 3 is a schematic structural diagram of a magnetic field loop of the axial bearing.

Fig. 4 is a schematic structural diagram of a radial bearing magnetic field loop.

Fig. 5 is a schematic structural diagram of a stator and a copper-clad magnetic field.

11-front bearing seat, 12-rear bearing seat, 13-sensor, 14-protective bearing, 51-radial bearing stator and 52-radial bearing rotor.

Detailed Description

The following describes in detail embodiments of the present invention with reference to the drawings.

Example 1

1-5, the motor comprises a shell 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; 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 face of the first shaft section 31 at the connecting position of 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 face of the second shaft section 32 at the connecting position of the third shaft section 33 and the second shaft section 32; the first shoulder 37 and the second shoulder 38 are both magnetically conductive surfaces, and the first shoulder 37 and the second shoulder 38 are respectively engaged with the stator magnetic circuit supporting end of the axial bearing 6. In this way, the magnetic conductive surfaces of the first shoulder 37 and the second shoulder 38 are grouped in pairs, and the axial position is kept under the drive of the stator magnetic circuit of the axial bearing 6; therefore, the axial bearing 6 is made into a structure without a thrust disc, the space is saved, and the mechanical property requirement is reduced.

Both the second shaft segments 32 and both the third shaft segments 33 are axially symmetrically distributed along the first shaft segment 31. The second shaft section 32 and the third shaft section 33 are connected by a bevel transition to reduce internal stresses between the different shaft sections.

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 with the driving end of the stator 2; the second shaft section 32 and the third shaft section 33 are engaged with the axial bearing 6 support end and the radial bearing 5 support end, respectively. The copper-clad layer 34 is integrated with the shaft, the mechanical property is excellent, and the limit of the rotating speed and the power of the high-speed motor is greatly improved. The heat conductivity of copper is 10 times higher than that of carbon fiber and 6.5 times higher than that of nickel-based alloy, and the heat dissipation of the motor is greatly improved. Copper clad layer 34 includes a lower recess 35 in the middle and raised portions 36 on both sides, lower recess 35 having the same width as the drive end of stator 2.

The outer surface of the third shaft section 33 is provided with a radial magnetic bearing rotor assembly, and the radial magnetic bearing rotor assembly is connected with the magnetic circuit supporting end of the radial bearing 5. The rotor assembly of the radial magnetic bearing and the stator magnetic field of the radial magnetic bearing 5 form a loop to enable the rotor to be suspended under magnetic force.

The motor shaft 3 further comprises fourth shaft segments 39, the two fourth shaft segments 39 being located outside the two third shaft segments 33, respectively; the outer surface of the fourth shaft section 39 is sleeved with punching sheets which are mutually stacked and attached in the axial direction, and the punching sheets on the fourth shaft section 39 are connected with the sensing end of the axial sensor to detect the axial position of the motor shaft 3.

The motor shaft 3 further includes a fifth shaft section 30, the two fifth shaft sections 30 are respectively located at the outer sides of 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 force provided by the radial bearing 5 and the axial bearing 6 disappears, and the motor shaft 3 falls to the position of the non-magnetic radial bearing to be supported to prevent the motor shaft 3 from being damaged by sudden falling.

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

Claims

1. A magnetic suspension high-speed asynchronous motor without a thrust disc comprises a shell (1), a stator (2), a motor shaft (3), a radial bearing (5) and an axial bearing (6); the motor shaft (3) is characterized by comprising a first shaft section (31), two second shaft sections (32) respectively positioned at the outer sides of two ends of the first shaft section (31) and two third shaft sections (33) respectively positioned at the outer sides of two ends of the second shaft sections (32); the diameter of the cylinder of the second shaft section (32) is smaller than that of the cylinder of the first shaft section (31), and a first shaft shoulder (37) is formed on the outer end face of the first shaft section (31) at the connecting position of 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 face of the second shaft section (32) at the connecting position of the third shaft section (33) and the second shaft section (32); the first shaft shoulder (37) and the second shaft shoulder (38) are magnetic conduction surfaces, and the first shaft shoulder (37) and the second shaft shoulder (38) are respectively connected with the stator magnetic circuit supporting end of the axial bearing (6).

2. The magnetic levitation high-speed asynchronous machine without a thrust disc as claimed in claim 1, characterized in that both the second shaft section (32) and the third shaft section (33) are axially symmetrically distributed along the first shaft section (31).

3. The magnetic levitation high-speed asynchronous motor without a thrust disc as recited in claim 1, characterized in that the second shaft section (32) and the third shaft section (33) are connected by a bevel transition.

4. The magnetic suspension high-speed asynchronous motor without the thrust disc is characterized in that 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 with the driving end of the stator (2); the second shaft section (32) and the third shaft section (33) are respectively connected with the supporting end of the axial bearing (6) and the supporting end of the radial bearing (5).

5. The magnetic levitation high-speed asynchronous motor without a thrust disc as claimed in claim 4, characterized in that the copper-clad layer (34) comprises a lower recess (35) in the middle and raised portions (36) on both sides, the lower recess (35) having the same width as the driving end of the stator (2).

6. The magnetically levitated high-speed asynchronous machine without a thrust disk according to claim 1, characterized in that the outer surface of the third shaft section (33) is provided with a radial magnetic bearing rotor assembly, which is engaged with the magnetic circuit supporting end of the radial bearing (5).

7. The magnetic levitation high-speed asynchronous machine without a thrust disc as claimed in claim 1, characterised in that the machine shaft (3) further comprises a fourth shaft section (39), the two fourth shaft sections (39) being located outside the two third shaft sections (33), respectively; the outer surface of the fourth shaft section (39) is sleeved with punching sheets which are mutually stacked and attached in the axial direction, and the punching sheets on the fourth shaft section (39) are connected with the induction end of the axial sensor.

8. The magnetic levitation high-speed asynchronous machine without a thrust disc as claimed in claim 7, characterised in that the machine shaft (3) further comprises a fifth shaft segment (30), the two fifth shaft segments (30) being located outside the two fourth shaft segments (39), respectively, and the outer surface of the fifth shaft segment (30) cooperating with the inner ring of the non-magnetic radial bearing.

9. The magnetic levitation high-speed asynchronous motor without the thrust disc as recited in claim 8, characterized in that the cylindrical outer surface of the fifth shaft section (30) is provided with end face teeth (301), and the end face teeth (301) are matched with the connection part of the impeller.

10. The magnetic suspension high-speed asynchronous motor without a thrust disc as recited in claim 8, characterized in that the outer end face of the fifth shaft section (30) is provided with screw holes, and the impeller is fixed on the screw holes and connected with the motor shaft (3).