WO2021114488A1

WO2021114488A1 - Permanent magnetic bearing

Info

Publication number: WO2021114488A1
Application number: PCT/CN2020/076889
Authority: WO
Inventors: 林英哲; 刘淑云; 吴立华; 董继勇
Original assignee: 南京磁谷科技股份有限公司
Priority date: 2019-12-12
Filing date: 2020-02-27
Publication date: 2021-06-17
Also published as: CN110848255A

Abstract

A permanent magnetic bearing, comprising a rotor core shaft (1), rotor assemblies, stator assemblies, and axial electromagnetic bearings (11). The rotor assemblies are respectively sleeved on both ends of the rotor core shaft (1). The stator assemblies are provided at the peripheries of the rotor assemblies. The axial electromagnetic bearings (11) are separately arranged at the periphery of the rotor core shaft (1) located at the outer sides of the rotor assemblies and the stator assemblies. Each rotor assembly comprises a rotor permanent magnet (3) and a rotor sheath (5). The rotor permanent magnet (3) is provided at the outer ring of the rotor core shaft (1). The rotor sheath (5) is provided at the outer ring of the rotor permanent magnet (3). Each stator assembly comprises a magnetic bearing seat (2), a stator permanent magnet (4), a stator sheath (6), and an end cover (9). The magnetic surface of the inner ring of the stator permanent magnet (4) has the same polarity as that of the magnetic surface of the outer ring of the rotor permanent magnet (3). The permanent magnetic bearing is simple in structure, small in size, low in cost, and easy to manufacture and mount, and is applied to a place with small load and stable operation.

Description

A kind of permanent magnetic bearing

Technical field

The invention belongs to the technical field of mechanical parts, and particularly relates to a permanent magnetic bearing.

Background technique

Magnetic bearing is a new type of high-performance bearing. Compared with traditional ball bearings, sliding bearings and oil film bearings, magnetic bearings have no mechanical contact, and the rotor can reach a high operating speed, with low mechanical wear, low energy consumption and noise. It has the advantages of small size, long life, no lubrication, no oil pollution, etc. It is especially suitable for special environments such as high speed, vacuum and ultra-clean.

The utility model patent with the bulletin number CN204284205U discloses a mounting structure for radial magnetic bearings and radial sensors. The radial magnetic bearing includes an upper pressure plate, a lower pressure plate and silicon steel sheet. The inner surface of the silicon steel sheet is equipped with a coil frame , The coil bobbin is wound with a coil, the outer circular arc surface of the silicon steel sheet is surrounded to form the outer cylindrical surface of the radial magnetic bearing, and the inner end of the coil bobbin is surrounded to form the inner cylindrical surface of the radial magnetic bearing. The upper pressure plate includes the upper For steps, middle steps and lower steps, a round hole is provided in the middle of the upper pressing plate, a number of through holes are evenly spaced around the round hole on the upper step, and a number of sets of perforations are formed on the lower step. The two outside are pin holes. Pin holes are formed on the lower platen opposite to the pin holes on the upper platen. The pin holes of the lower platen and the pin holes of the upper platen are provided with cylindrical pins, which are arranged on the middle step. There is a magnetic bearing circuit board, and the end of the radial sensor is electrically connected to the magnetic bearing circuit board after being arranged in the through hole. Radial electromagnetic bearings require coils, displacement sensors, and magnetic bearing control systems, which are complex in structure, large in volume, and difficult to establish a high-precision control system.

Summary of the invention

Technical purpose: In view of the problems in the prior art, the present invention discloses a permanent magnetic bearing, which replaces the radial electromagnetic bearing with a radial permanent magnetic bearing, does not require coils, displacement sensors and a magnetic bearing control system, and has a simple structure and volume. It is small, does not require power, and does not need to be controlled.

Technical solution: The present invention adopts the following technical solution: a permanent magnetic bearing, including a rotor core shaft, a rotor assembly, a stator assembly and an axial electromagnetic bearing, wherein the rotor assembly is sleeved on both ends of the rotor core shaft, and the outer circumference of the rotor assembly A stator assembly is provided, and axial electromagnetic bearings are respectively arranged on the outer circumference of the rotor core shaft located outside the rotor assembly and the stator assembly;

The rotor assembly includes a rotor permanent magnet and a rotor sheath, wherein the rotor core shaft outer ring is provided with a rotor permanent magnet, and the rotor permanent magnet outer ring is provided with a rotor sheath;

The stator assembly includes a magnetic bearing seat, a stator permanent magnet, a stator sheath and an end cover. The magnetic bearing seat is provided with a stator permanent magnet on the side close to the rotor assembly, and a stator sheath is arranged on the outer side of the stator permanent magnet. An end cover fixed to the magnetic bearing seat is arranged on the side, the stator permanent magnet and the rotor permanent magnet are located on the same axis, and the magnetic surface of the stator permanent magnet inner ring and the rotor permanent magnet outer ring have the same polarity.

Preferably, the magnetic isolation sheet and pure iron are arranged in sequence outside the permanent magnet of the rotor of the present invention.

Preferably, there is an interference fit between the rotor permanent magnet, the magnetic isolation sheet, the pure iron and the rotor core shaft of the present invention, and the interference fit between the rotor sheath and the rotor permanent magnet.

Preferably, the rotor core shaft of the present invention has a structure with steps at both ends.

Preferably, the outer diameter of the rotor sheath, the outer diameter of the magnetic isolation sheet, and the outer diameter of the pure iron of the present invention are not greater than the maximum outer diameter of the rotor core shaft.

Preferably, the end cover of the present invention and the magnetic bearing seat are fixed by screws.

Preferably, the inner diameter of the stator sheath and the inner diameter of the end cover of the present invention are not less than the minimum inner diameter of the magnetic bearing seat.

Preferably, the rotor sheath of the present invention is a high-temperature alloy, and the stator sheath is a carbon fiber sheath.

Preferably, the axial electromagnetic bearing of the present invention controls the axial position of the rotor core shaft, and the stator assembly and the rotor assembly use the mutual thrust between the stator permanent magnets and the rotor permanent magnets to float the rotor core at the central position of the inner hole of the magnetic bearing , Control the radial position of the rotor core shaft.

Beneficial effects: The present invention has the following beneficial effects:

(1) The present invention uses radial permanent magnetic bearings instead of radial electromagnetic bearings, and uses the mutual thrust between the permanent magnetic poles to float the rotor at the center of the inner hole of the magnetic bearing. No coils, displacement sensors and magnetic bearing control systems are needed. Need electric energy, no need to establish a high-precision control system;

(2) The present invention is simple in structure, small in size, low in cost, easy to manufacture and install, and is mainly used in places where the load is small and the work is stable;

(3) The interference fit between the parts of the present invention has good centering performance, high load-bearing capacity, can bear impact load, and weaken the shaft strength;

(4) In the present invention, a magnetic isolation sheet is used to isolate the contact between the metal object and the electromagnetic signal to prevent the attenuation of the electromagnetic signal. At the same time, it can gather the magnetic flux of the induced magnetic field, enhance the magnetic induction intensity of the receiving end, prevent heat generation, save electric energy and improve conversion efficiency.

Description of the drawings

Figure 1 is a schematic diagram of the structure of a permanent magnetic bearing of the present invention;

Figure 2 is a schematic diagram of the structure of the stator assembly of the present invention;

Figure 3 is a schematic diagram of the structure of the rotor assembly of the present invention;

Among them, rotor core shaft 1, magnetic bearing seat 2, rotor permanent magnet 3, stator permanent magnet 4, rotor sheath 5, stator sheath 6, magnetic isolation sheet 7, pure iron 8, end cover 9, screw 10, axial Magnetic bearing 11.

Detailed ways

The present invention will be further explained below in conjunction with the accompanying drawings.

The invention discloses a permanent magnetic bearing, as shown in Fig. 1, comprising a rotor core shaft 1, a rotor assembly, a stator assembly and an axial electromagnetic bearing 11. The two ends of the rotor core shaft 1 are respectively sleeved with the rotor assembly, and the rotor A stator assembly is arranged on the outer periphery of the assembly, and axial electromagnetic bearings 11 are arranged on the outer periphery of the rotor core shaft 1 located outside the rotor assembly and the stator assembly, respectively.

The rotor core shaft 1 may have a structure with steps at both ends.

As shown in Figure 3, the rotor assembly includes a rotor permanent magnet 3 and a rotor sheath 5. The outer ring of the rotor core shaft 1 is provided with a rotor permanent magnet 3, and the outer ring of the rotor permanent magnet 3 is provided with a rotor sheath 5. 5 is a high-temperature alloy sheath. Magnetic isolation sheets 7 and pure iron 8 are arranged on the outer side of the rotor permanent magnet 3 in sequence. The rotor permanent magnet 3, the magnetic isolation sheet 7, the pure iron 8 and the rotor core shaft 1 have an interference fit. The rotor sheath The interference fit between 5 and the rotor permanent magnet 3, the outer diameter of the rotor sheath 5, the outer diameter of the magnetic isolation sheet 7, and the outer diameter of the pure iron 8 shall not be greater than the maximum outer diameter of the rotor core shaft 1.

As shown in Figure 2, the stator assembly includes a magnetic bearing housing 2, a stator permanent magnet 4, a stator sheath 6, an end cover 9 and a screw 10. The magnetic bearing housing 2 is provided with a stator permanent magnet 4 on the side close to the rotor assembly. A stator sheath 6 is arranged on the outside of the stator permanent magnet 4. The stator sheath 6 is a carbon fiber sheath. One side of the stator permanent magnet 4 is provided with an end cover 9 fixed to the magnetic bearing housing 2, between the end cover 9 and the magnetic bearing housing 2. Fixed by screws 10, the inner diameter of the stator sheath 6 and the inner diameter of the end cover 9 are not less than the minimum inner diameter of the magnetic bearing housing 2. The stator permanent magnet 4 and the rotor permanent magnet 3 are located on the same axis. The polarity of the magnetic surface of the outer ring of the magnet 3 is the same.

In the present invention, the axial electromagnetic bearing 11 controls the axial position of the rotor core shaft 1. The stator assembly and the rotor assembly use the mutual thrust between the stator permanent magnet 4 and the rotor permanent magnet 3 to float the rotor core shaft 1 on the center of the magnetic bearing inner hole. Position, which controls the radial position of the rotor core shaft 1.

The above are only preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims

A permanent magnetic bearing, which is characterized by comprising a rotor core shaft (1), a rotor assembly, a stator assembly and an axial electromagnetic bearing (11), wherein the rotor core shaft (1) is respectively sleeved on both ends of the rotor assembly A stator assembly is arranged on the outer periphery of the rotor assembly, and axial electromagnetic bearings (11) are arranged on the outer periphery of the rotor core shaft (1) located outside the rotor assembly and the stator assembly;

The rotor assembly includes a rotor permanent magnet (3) and a rotor sheath (5), wherein the outer ring of the rotor core shaft (1) is provided with a rotor permanent magnet (3), and the rotor permanent magnet (3) outer ring A rotor sheath (5) is provided;

The stator assembly includes a magnetic bearing seat (2), a stator permanent magnet (4), a stator sheath (6) and an end cover (9), wherein the magnetic bearing seat (2) is arranged on a side close to the rotor assembly A stator permanent magnet (4), a stator sheath (6) is arranged on the outer side of the stator permanent magnet (4), and an end cover (9) fixed to the magnetic bearing seat (2) is arranged on one side of the stator permanent magnet (4) ), the stator permanent magnet (4) and the rotor permanent magnet (3) are located on the same axis, and the magnetic surface of the inner ring of the stator permanent magnet (4) and the outer ring of the rotor permanent magnet (3) have the same polarity.
The permanent magnetic bearing according to claim 1, characterized in that a magnetic isolation sheet (7) and pure iron (8) are arranged on the outer side of the rotor permanent magnet (3) in sequence.
The permanent magnetic bearing according to claim 2, characterized in that, the rotor permanent magnet (3), the magnetic isolation sheet (7), the pure iron (8) and the rotor core shaft (1) have an interference fit , An interference fit between the rotor sheath (5) and the rotor permanent magnet (3).
The permanent magnetic bearing according to claim 2, wherein the rotor core shaft (1) has a structure with steps at both ends.
A permanent magnetic bearing according to claim 4, characterized in that the outer diameter of the rotor sheath (5), the outer diameter of the magnetic shield (7), and the outer diameter of the pure iron (8) are not greater than the rotor core shaft ( 1) The maximum outer diameter.
The permanent magnetic bearing according to claim 1, wherein the end cover (9) and the magnetic bearing seat (2) are fixed by screws (10).
The permanent magnetic bearing according to claim 1, wherein the inner diameter of the stator sheath (6) and the inner diameter of the end cover (9) are not less than the smallest inner diameter of the magnetic bearing seat (2).
The permanent magnetic bearing according to claim 1, wherein the rotor sheath (5) is a high-temperature alloy, and the stator sheath (6) is a carbon fiber sheath.
The permanent magnetic bearing according to claim 1, wherein the axial electromagnetic bearing (11) controls the axial position of the rotor core shaft (1), and the stator assembly and the rotor assembly use stator permanent magnets ( 4) The mutual thrust between the rotor permanent magnets (3) floats the rotor core shaft (1) at the center position of the inner hole of the magnetic bearing, and controls the radial position of the rotor core shaft (1).