CN111022499A

CN111022499A - Radial Large Capacity Hybrid Magnetic Bearings

Info

Publication number: CN111022499A
Application number: CN201911420062.7A
Authority: CN
Inventors: 叶小婷; 王紫欣; 吴帅; 武莎莎; 胡蔼; 朱为国; 丁祖军; 张涛
Original assignee: Huaiyin Institute of Technology
Current assignee: Huaiyin Institute of Technology
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-04-17
Anticipated expiration: 2039-12-31
Also published as: CN111022499B

Abstract

The invention relates to a non-mechanical contact magnetic bearing, and discloses a hybrid magnetic bearing with large radial bearing capacity, which comprises a stator and a rotor located in the inner ring of the stator. The axial core, the right radial stator core and the non-magnetically conductive housing. The rotor includes a left rotor core, an axially magnetized permanent magnet ring, a right rotor core and a rotating shaft. In the present invention, an axially magnetized rotor permanent magnet ring provides static bias magnetic flux, and the radial control magnetic flux generated by the energization of the radial control winding adjusts the corresponding bias magnetic flux; the hybrid magnetic bearing of this structure has no windings on the radial magnetic poles. , The magnetic pole area can be designed to the maximum, which effectively increases the radial bearing capacity and reduces the axial length, with small volume, compact structure, high critical speed and high suspension force density.

Description

Radial large-bearing-capacity hybrid magnetic bearing

Technical Field

The invention relates to the technical field of non-mechanical contact magnetic bearings, in particular to an axial winding hybrid magnetic bearing which can be used as a non-contact suspension support of high-speed transmission parts such as a flywheel system, a machine tool electric spindle, a centrifugal machine and the like.

Background

The magnetic bearing is a novel high-performance bearing which suspends a rotor in a space by utilizing electromagnetic force between a stator and the rotor so that the stator and the rotor are not in mechanical contact. Currently, magnetic bearings are classified into ac and dc types according to the type of control current. The alternating current type magnetic bearing adopts a three-pole magnetic bearing driven by a three-phase inverter, so that the volume of a power amplifier and the cost of the magnetic bearing are reduced, but a three-pole structure is asymmetric in space, and the sum of three-phase currents of the three-phase inverter is required to be zero, so that the maximum suspension force of the suspension force in two radial degrees of freedom is unequal; in addition, the suspension force of the three-pole alternating current magnetic bearing is serious in nonlinearity with current and displacement, and two radial degrees of freedom are coupled. The direct-current magnetic bearing is generally an octopole or quadrupole structure, and the radial two-degree-of-freedom of the magnetic bearing of the structure needs four paths of unipolar or two paths of bipolar direct-current power, so that the performance is excellent.

The structural commonality of the existing four-pole hybrid magnetic bearing is that a radial stator magnetic pole winds a control winding to generate radial control magnetic flux, and the radial control magnetic flux passes through a radial working air gap and interacts with corresponding bias magnetic flux to generate radial suspension force. The radial control winding of the hybrid magnetic bearing with the structure occupies a radial space, the area of a radial magnetic pole cannot be maximized, and the winding is protected by arranging shells positioned on two sides, so that the radial bearing capacity is small, the axial length is long, and the critical rotating speed is low.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems in the prior art, the invention provides a radial large-bearing capacity hybrid magnetic bearing, wherein a radial magnetic pole has no winding, the area of the magnetic pole can be designed to be maximum, the radial bearing capacity is effectively increased, the axial length is reduced, the volume is small, the structure is compact, the critical rotating speed is high, and the suspension force density is large.

The technical scheme is as follows: the invention provides a radial high-bearing capacity hybrid magnetic bearing, which comprises a stator and a rotor positioned in an inner ring of the stator, wherein the stator comprises a left radial stator core, 4 axial cores, a right radial stator core and a non-magnetic-conductive shell, wherein the left radial stator core, the 4 axial cores, the right radial stator core and the non-magnetic-conductive shell are sequentially arranged from left to right, are equidistantly distributed on the circumferential edge and have the same size; the left radial stator core and the right radial stator core are uniformly divided into four blocks along the circumference by 4 magnetic isolation aluminum blocks respectively; each axial iron core is positioned between two magnetic isolation aluminum blocks which are adjacent in the radial direction on the left side and two magnetic isolation aluminum blocks which are adjacent in the radial direction on the right side, and a centralized radial control winding is wound on each axial iron core; the non-magnetic-conduction shell is arranged on the outer sides of the left radial stator core and the right radial stator core;

the rotor comprises a left rotor iron core, an axially magnetized permanent magnet ring, a right rotor iron core and a rotating shaft which are sequentially arranged from left to right; the left rotor iron core and the right rotor iron core are respectively opposite to the left radial stator iron core and the right radial stator iron core, the rotor iron core parts with the same width are respectively provided with a left suction disc and a right suction disc which are protruded, the left suction disc and the right suction disc respectively form a left radial air gap and a right radial air gap with the left radial stator iron core and the right radial stator iron core, and the rotating shaft penetrates through the left rotor iron core, the right rotor iron core and the axially magnetized permanent magnet ring.

Further, the radial control winding is used for radial suspension control, and opposite radial two-pole windings are connected in series in an opposite direction or in parallel.

Further, the left and right radial stator cores, the axial core, and the left and right rotor cores are made of a magnetic conductive material.

Furthermore, the permanent magnet ring magnetized in the axial direction is made of rare earth permanent magnet materials.

Furthermore, the axial lengths of the left suction disc and the right suction disc are equal to the axial lengths of the left radial stator core and the right radial stator core.

Has the advantages that:

1. the magnetic pole area of the hybrid magnetic bearing with large radial bearing capacity can be designed to be maximum, the radial bearing capacity is effectively increased, the axial length is reduced, the volume is small, the structure is compact, the critical rotating speed is high, and the suspension force density is large.

2. The stator of the invention adopts 4 axial iron cores, and the four axial iron cores generate a direct current type hybrid magnetic bearing.

Drawings

FIG. 1 is a schematic view of a radial high-bearing capacity hybrid magnetic bearing according to the present invention;

FIG. 2 is a magnetic levitation flux diagram of the radial high-bearing hybrid magnetic bearing of the present invention;

fig. 3 is a left side view of an axial core of the radial high-bearing hybrid magnetic bearing of the present invention.

1-left radial stator core, 2-axial core, 3-right radial stator core, 4-non-magnetic-conductive shell, 5-magnetic-isolation aluminum block, 6-radial control winding, 7-left rotor core, 8-right rotor core, 9-axial magnetized permanent magnet ring, 10-rotating shaft, 11-left suction disc, 12-right suction disc, 13-left radial air gap, 14-right radial air gap, 15-radial suspension control magnetic flux and 16-static bias magnetic flux.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "connected" and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The invention relates to the technical field of non-mechanical contact magnetic bearings, and discloses a radial large-bearing-capacity hybrid magnetic bearing which comprises a stator and a rotor positioned in the inner ring of the stator, and aims to solve the problems that a radial control winding of the traditional hybrid magnetic bearing occupies a radial space, the area of a radial magnetic pole cannot be maximized, and a shell positioned on two sides is required to protect the winding, so that the radial bearing capacity is small, the axial length is long, and the critical rotating speed is low.

The stator comprises a left radial stator core 1, a left radial stator core 4, a right radial stator core 3 and a non-magnetic-conduction shell 4, wherein the left radial stator core 1, the right radial stator core 4 and the non-magnetic-conduction shell are sequentially arranged from left to right, and are distributed on the circumference at equal intervals and have the same size. The left radial stator core 1 and the right radial stator core 3 are uniformly circumferentially divided into a plurality of blocks by the magnetic shielding aluminum blocks 5 corresponding to the axial core 2, the number of the axial core 2 is 4 in this embodiment, the left radial stator core 3 is uniformly circumferentially divided into 4 blocks by the 4 magnetic shielding aluminum blocks 5, the right radial stator core 3 is uniformly circumferentially divided into 4 blocks by the 4 magnetic shielding aluminum blocks 5, the left radial stator core 3 is divided into 4 blocks, the radian of each block is the same as that of each axial core 2, and the positions of the 4 divided blocks are in one-to-one correspondence with each axial core 2.

Each axial core 2 is located between two left-side radially adjacent flux barrier aluminum blocks 5 and two right-side radially adjacent flux barrier aluminum blocks 5, see fig. 1, that is, each axial core 2 is located between two left-side radially adjacent flux barrier aluminum blocks 5 of the left radial stator core 1 and two right-side radially adjacent flux barrier aluminum blocks 5 of the right radial stator core 3.

A concentrated radial control winding 6 is wound on each axial core 2. And the non-magnetic conductive shell 4 is arranged at the outer sides of the left radial stator core and the right radial stator core.

The rotor comprises a left rotor iron core 7, an axially magnetized permanent magnet ring 9, a right rotor iron core 8 and a rotating shaft 10 which are sequentially arranged from left to right. The left rotor core 7 is opposite to the left radial stator core 1 in position, a rotor core part with the same width is provided with a convex left suction disc 11, the right rotor core 8 is opposite to the right radial stator core 3 in position, a rotor core part with the same width is provided with a convex right suction disc 12, namely referring to the attached drawing 1, the left radial stator core 1 and the right radial stator core 3 are in a circular ring hollow design, the left rotor core 7 is opposite to the left radial stator core 1 in position and is positioned in a circular ring of the left radial stator core 1, and the axial length of the left suction disc 11 arranged on the left rotor core 7 is the same as that of the left radial stator core 1. The right rotor core 8 is opposite to the right radial stator core 3 and is positioned in the ring of the right radial stator core 3, and the axial length of a right suction disc 12 arranged on the right rotor core 8 is the same as that of the right radial stator core 3. The left suction disc 11 and the inner circular wall of the left radial stator core 1 form a left radial air gap 13, and the right suction disc 12 and the inner circular wall of the right radial stator core 3 form a right radial air gap 14.

The rotating shaft 10 penetrates through the left rotor core 7, the right rotor core 8 and the axially magnetized permanent magnet ring 9 to play a supporting role.

The radial control winding 6 is used for radial suspension control, and opposite radial two-pole windings are connected in series in an opposite direction or in parallel.

The left radial stator core 1, the right radial stator core 3, the axial core 2, and the left rotor core 7 and the right rotor core 8 are made of a magnetic conductive material. The permanent magnet ring 9 magnetized in the axial direction is made of rare earth permanent magnet material.

In the present embodiment, a quadrupole hybrid magnetic bearing, which is a direct current magnetic bearing, is formed using 4 axial cores 2.

The permanent magnet ring 9 magnetized in the axial direction provides static bias magnetic flux 16, and the magnetic circuit of the static bias magnetic flux 16 is as follows: the magnetic flux starts from the N pole of the axially magnetized permanent magnet ring 9 and returns to the S pole of the axially magnetized permanent magnet ring 9 through the left suction disc 11, the left radial air gap 13, the left radial stator core 1, the top axial core 2, the right radial stator core 3, the right radial air gap 14 and the right suction disc 12.

Assuming that 4 axial cores 2 are marked as an axial core 2d, an axial core 2e, an axial core 2f, and an axial core 2g, respectively, from the left side view direction of fig. 1, see fig. 3.

The radial suspension control magnetic flux 15 generated by electrifying the radial control winding 6 wound on the top axial iron core 2d has a magnetic circuit as follows: the left radial stator core 1, the left radial air gap 13, the left suction disc 11, the left radial stator core 1, the axial core 2g, the right radial stator core 3, the right radial air gap 14, the right suction disc 12, the right radial stator core 3, and the axial core 2d form a closed path.

Suspension principle: the static bias magnetic flux 16 in the radial direction interacts with the radial levitation control magnetic flux 15, so that the air gap magnetic field superposition on the same side of the radial eccentricity direction of the rotor is weakened, and the air gap magnetic field superposition on the opposite direction is strengthened, and a force opposite to the offset direction of the rotor is generated on the rotor to pull the rotor back to the radial balance position.

The above embodiments are merely illustrative of the technical concepts and features of the present invention, and the purpose of the embodiments is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. a radial high bearing capacity hybrid magnetic bearing, comprising a stator and a rotor positioned at the inner ring of the stator, is characterized in that,

The stator includes a left radial stator iron core arranged in sequence from left to right, 4 axial iron cores of the same size distributed at equal distances around the circumference, a right radial stator iron core and a non-magnetically conductive shell; The stator iron core is divided into four pieces evenly along the circumference by four magnetic isolation aluminum blocks; each axial iron core is located on the left radially adjacent two magnetic isolation aluminum blocks and the right radially adjacent two magnetic isolation aluminum blocks. Centralized radial control windings are wound between and on the magnetic aluminum blocks; the non-magnetically conductive housings are arranged outside the left and right radial stator cores;

The rotor includes a left rotor iron core, an axially magnetized permanent magnet ring, a right rotor iron core and a rotating shaft arranged in sequence from left to right; the left and right rotor iron cores are respectively connected with the left and right radial stator iron cores. The rotor cores with opposite positions and the same width are respectively provided with protruding left and right suction discs, and the left and right suction discs respectively form left and right radial air gaps with the left and right radial stator cores. The rotating shaft passes through the left and right rotor cores and the axially magnetized permanent magnet rings.

2 . The hybrid magnetic bearing with large radial bearing capacity according to claim 1 , wherein the radial control winding is used for radial suspension control, and the opposite radial two-pole windings are connected in series or in parallel. 3 .

3 . The hybrid magnetic bearing with large radial bearing capacity according to claim 1 , wherein the left and right radial stator iron cores, the axial iron cores and the left and right rotor iron cores are all made of magnetically conductive materials. 4 .

4 . The hybrid magnetic bearing with large radial bearing capacity according to claim 1 , wherein the axially magnetized permanent magnet ring is made of rare earth permanent magnet material. 5 .

5 . The hybrid magnetic bearing with large radial bearing capacity according to claim 1 , wherein the left suction plate, the right suction plate and the left and right radial stator cores have the same axial length. 6 .