CN112983988B - Composite magnetic suspension bearing and magnetic suspension bearing system - Google Patents

Abstract

The invention relates to the technical field of bearings and discloses a composite magnetic suspension bearing and a magnetic suspension bearing system. The composite magnetic suspension bearing provided by the invention realizes that energy is provided for the axial direction and the radial direction by a minimum ferromagnetic path through a permanent magnetic ring, realizes the composition of the radial magnetic suspension bearing and the axial magnetic suspension bearing, shortens the axial length of the composite magnetic suspension bearing, reduces the cost, is beneficial to improving the dynamic characteristic of a rotor, eliminates the electric power loss of a generated bias magnetic field, reduces the heat productivity of the bearing, consumes less power and simplifies the control system of the composite magnetic suspension bearing.

Description

Composite magnetic suspension bearing and magnetic suspension bearing system

Technical Field

The invention relates to the technical field of bearings, in particular to a composite magnetic suspension bearing and a magnetic suspension bearing system.

Background

In a conventional magnetic suspension bearing system, whether electromagnetic bias or permanent magnet bias is adopted, three actuators, namely two radial actuators and one thrust actuator, are usually adopted in a five-axis system, and each actuator works independently to stably support and control a magnetic suspension rotor.

The magnetic suspension bearing is mainly applied to the field of high rotating speed, the rotating speed of a rotor requires tens of thousands of revolutions or even hundreds of thousands of revolutions, the rotating speed of the rotor can be improved depending on the dynamic characteristic of the rotor, and the dynamic characteristic of the rotor is limited by the size of a rotor system. The magnetic suspension bearing system with three actuators limits the shape and size of the rotor, so that the rotating speed of the rotor is difficult to increase.

Disclosure of Invention

The invention aims to provide a composite magnetic suspension bearing and a magnetic suspension bearing system, which can solve the problem that the rotation speed of a rotor is difficult to increase by adopting the magnetic suspension bearing system with three actuators.

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

a composite magnetic suspension bearing, which is arranged on a rotating shaft, comprises:

the rotor iron core and the thrust discs positioned on two axially opposite sides of the rotor iron core are fixedly sleeved outside the rotating shaft;

the stator magnetic poles are arranged on one side, back to the rotor core, of each thrust disc at intervals in the axial direction of the thrust disc;

the radial stator core is sleeved outside the rotor core and is arranged at intervals with the rotor core in the radial direction, four salient poles which are uniformly distributed in the circumferential direction are arranged on the radial stator core, radial stator coils are wound on the salient poles, and a thrust coil is arranged on one side, facing the radial stator core, of each stator magnetic pole;

the permanent magnet ring is fixedly sleeved outside the radial stator core;

the two stator magnetic poles are connected through the spacer ring, and the spacer ring is fixedly sleeved outside the permanent magnet ring;

stator magnetic pole with it is equipped with solid fixed ring to press from both sides between the radial stator core, thrust coil is spacing in gu fixed ring stator magnetic pole the spacer ring the permanent magnetism ring with in the installation space that radial stator core encloses.

As a preferable technical solution of the above composite magnetic suspension bearing, the permanent magnet ring is in interference fit with the spacer ring, and/or the permanent magnet ring is in interference fit with the radial stator core.

As a preferred technical solution of the above composite magnetic suspension bearing, the stator magnetic poles are of an integral structure.

The preferable technical scheme of the composite magnetic suspension bearing comprises a first magnetic pole and a second magnetic pole, wherein one end of the first magnetic pole is connected to the second magnetic pole, and the other end of the first magnetic pole penetrates through the second magnetic pole, is opposite to the rotor core and is arranged at intervals with the rotor core.

The preferable technical scheme of the composite magnetic suspension bearing comprises two halves, wherein the two halves are connected with each other to form the stator magnetic pole in a circular ring shape.

As a preferred technical solution of the above composite magnetic suspension bearing, the composite magnetic suspension bearing further comprises a displacement detection unit for detecting axial displacement and radial displacement of the rotating shaft.

As a preferred technical scheme of the composite magnetic suspension bearing, the permanent magnet ring is of an integral structure.

As a preferable technical scheme of the composite magnetic suspension bearing, a plurality of permanent magnets which are sequentially connected in the circumferential direction form a circular ring structure.

The invention also provides a magnetic suspension bearing system which comprises the composite magnetic suspension bearing.

As a preferred technical scheme of the magnetic suspension bearing system, the magnetic suspension bearing system further comprises a rotating shaft and a radial magnetic suspension bearing sleeved outside the rotating shaft, wherein the composite magnetic suspension bearing and the radial magnetic suspension bearing are arranged at two axial ends of the rotating shaft.

The invention has the beneficial effects that: the composite magnetic suspension bearing provided by the invention realizes that energy is provided for the axial direction and the radial direction by a minimum ferromagnetic path through a permanent magnetic ring, realizes the composition of the radial magnetic suspension bearing and the axial magnetic suspension bearing, shortens the axial length of the composite magnetic suspension bearing, reduces the cost, is beneficial to improving the dynamic characteristic of a rotor, eliminates the electric power loss of a generated bias magnetic field, reduces the heat productivity of the bearing, consumes less power and simplifies the control system of the composite magnetic suspension bearing.

The two stator magnetic poles are connected through the spacing ring, and the permanent magnet ring and the radial stator iron core are limited in the radial direction; the spacing ring and the radial stator core are connected through the permanent magnet ring, and the radial stator core is axially limited by the permanent magnet ring; the thrust coil is limited by the fixing ring so as to limit the thrust coil in an installation space defined by the fixing ring, the stator magnetic pole, the spacing ring, the permanent magnetic ring and the radial stator core.

The invention also provides a magnetic suspension bearing system, which comprises the rotating shaft and the composite magnetic suspension bearing, wherein an axial magnetic suspension bearing and a radial magnetic suspension bearing are integrated into the composite magnetic suspension bearing, and for a five-axis system, the radial magnetic suspension bearing can be cancelled, so that the axial size of a motor adopting the magnetic suspension bearing system is shortened, and the dynamic characteristic of a rotor is favorably improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings may be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a cross-sectional view of a composite magnetic bearing provided by an embodiment of the present invention;

FIG. 2 is a side view of a stator pole provided by an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a stator pole provided by an embodiment of the present invention;

FIG. 4 is a side view of a stator pole provided in accordance with another embodiment of the present invention;

FIG. 5 is a cross-sectional view of FIG. 4;

fig. 6 is a cross-sectional view of a stator pole provided in accordance with another embodiment of the present invention;

fig. 7 is a diagram of the matching relationship of the spacer ring, the permanent magnet ring and the radial stator core provided by the embodiment of the invention;

fig. 8 is a side view of a permanent magnet ring provided by an embodiment of the present invention;

fig. 9 is a side view of a permanent magnet ring provided in accordance with another embodiment of the present invention;

FIG. 10 is a cross-sectional view of a magnetic bearing system provided by an embodiment of the present invention.

In the figure:

1. a rotor core; 2. a thrust disc; 3. a stator magnetic pole; 31. a first magnetic pole; 311. a first step magnetic pole; 312. a second step magnetic pole; 32. a second magnetic pole; 33. a first half; 34. the second half; 4. a radial stator core; 41. salient poles; 5. a permanent magnet ring; 6. a thrust coil; 7. a radial stator coil; 8. a fixing ring; 9. a spacer ring; 10. a displacement detection unit;

100. a composite magnetic suspension bearing; 200. a radial magnetic suspension bearing; 300. a rotating shaft.

Detailed Description

In order to make the technical problems solved, the technical solutions adopted and the technical effects achieved by the present invention clearer, the technical solutions of the present invention are further described below by way of specific embodiments with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be further noted that, for the convenience of description, only some but not all of the elements associated with the present invention are shown in the drawings.

As shown in fig. 1 and 2, the present embodiment provides a composite magnetic suspension bearing, which is mounted on arotating shaft 300, and maintains therotating shaft 300 in a floating state by radial and axial movements of therotating shaft 300.

The composite magnetic suspension bearing 100 comprises a rotor core 1, thrust discs 2, statormagnetic poles 3,radial stator cores 4 and permanent magnet rings 5, wherein the thrust discs 2 are positioned on two axially opposite sides of the rotor core 1, and the thrust discs 2 and the rotor core 1 are fixedly sleeved outside arotating shaft 300; one side of each thrust disc 2, which is back to the rotor core 1, is provided with a statormagnetic pole 3 which is axially arranged at an interval with the thrust disc 2, and one side of the statormagnetic pole 3, which faces theradial stator core 4, is provided with athrust coil 6; theradial stator core 4 is sleeved outside the rotor core 1 and is arranged at intervals with the rotor core 1 in the radial direction, foursalient poles 41 which are uniformly distributed in the circumferential direction are arranged on theradial stator core 4, and aradial stator coil 7 is wound on thesalient poles 41; thepermanent magnet ring 5 is fixedly sleeved outside theradial stator core 4.

The thrust disc 2 and the statormagnetic pole 3 are arranged at intervals to form an axial air gap, thepermanent magnet ring 5 generates magnetic flux in the axial air gap to adjust the size of the axial air gap between the thrust disc 2 and the statormagnetic pole 3, and B shown in figure 1 represents the axial air gap; a radial air gap is formed between the rotor core 1 and theradial stator core 4, a shown in fig. 1 indicates the radial air gap, thepermanent magnet ring 5 generates magnetic flux in the radial air gap to adjust the size of the radial air gap between the rotor core 1 and theradial stator core 4, and therotating shaft 300 is kept in a magnetic suspension state by controlling the axial air gap and the radial air gap, so as to meet the operation requirement of the bearing. It should be noted that the smaller the radial air gap, the greater the magnetic flux density; the smaller the axial air gap, the greater the magnetic flux density.

In the embodiment, the minimum ferromagnetic path is used for providing energy to the axial direction and the radial direction through thepermanent magnet ring 5, the combination of the radial magnetic suspension bearing and the axial magnetic suspension bearing is realized, the axial length of the composite magnetic suspension bearing 100 is shortened, the cost is reduced, the dynamic characteristic of a rotor is favorably improved, the electric power loss of a generated bias magnetic field is eliminated, the heat productivity of the bearing is reduced, the power consumption is low, and the control system of the composite magnetic suspension bearing 100 is simplified.

The composite magnetic suspension bearing 100 provided by the embodiment is a permanent magnet biased magnetic suspension bearing, the permanent magnet bias field is unstable, and an active closed-loop servo control is required to keep the axial air gaps between the statormagnetic poles 3 and the corresponding thrust discs 2 equal, and the radial air gaps between the rotor iron cores 1 and the radialstator iron cores 4 equal. Specifically, the composite magnetic suspension bearing 100 provided by the present embodiment further includes adisplacement detection unit 10 for detecting the axial displacement and the radial displacement of therotating shaft 300. The axial control force is generated by electrifying the twothrust coils 6, the thrust coils 6 are electrified with the same polarity, so that electromagnetic magnetic flux is generated, when the two axial air gaps are not equal, the permanent magnetic flux in one axial air gap can be increased, and the magnetic flux in the opposite direction can be reduced, so that the axial force balance is kept.

The radial control force is generated by energizing radial stator coils 7 wound around foursalient poles 41 of theradial stator core 4, the pair of radial stator coils 7 are spaced 180 degrees apart, and the pair of radial stator coils 7 are energized simultaneously to generate electromagnetic flux which is added to the permanent magnetic flux in the radial air gap on one side of therotating shaft 300 and subtracted from the permanent magnetic flux in the radial air gap on the other side of therotating shaft 300, thereby generating the radial control force.

Further, a fixingring 8 is clamped between the statormagnetic pole 3 and theradial stator core 4, and thethrust coil 6 is limited in a mounting space surrounded by the fixingring 8, the statormagnetic pole 3 and theradial stator core 4.

In consideration of the manufacturability of the power assembly, in the present embodiment, the statormagnetic pole 3 is a split structure. As shown in fig. 3, the statormagnetic pole 3 includes a firstmagnetic pole 31 and a secondmagnetic pole 32, one end of the firstmagnetic pole 31 is connected to the secondmagnetic pole 32, the other end of the first magnetic pole passes through the secondmagnetic pole 32 and faces the rotor core 1, and is spaced apart from the rotor core 1, and the fixingring 8 is clamped between theradial stator core 4 and the secondmagnetic pole 32.

The firstmagnetic pole 31 and the secondmagnetic pole 32 are both in a stepped annular structure, the inner hole of the secondmagnetic pole 32 is a stepped hole and comprises a first hole, a second hole and a third hole which are sequentially arranged, wherein the aperture of the third hole, the aperture of the first hole and the aperture of the second hole are sequentially increased. The firstmagnetic pole 31 includes a first steppedmagnetic pole 311 and a second steppedmagnetic pole 312, and an outer diameter of the first steppedmagnetic pole 311 is larger than an outer diameter of the second steppedmagnetic pole 312. The first stepmagnetic pole 311 is completely disposed in the first hole and abuts against the step surfaces formed by the first hole and the second hole, and the first stepmagnetic pole 311 and the secondmagnetic pole 32 are connected by a plurality of circumferentially arranged bolts. The second steppedmagnetic pole 312 passes through the second hole and faces the rotor core 1 and is spaced apart from the rotor core 1. Third hole and second stepmagnetic pole 312 enclose into the mounting groove, and solid fixedring 8 presss from both sides and locates between the ladder face that second hole and third hole formed andradial stator core 4, and the resin filling is fixed inthrust coil 6 between the outer wall of solid fixedring 8 and the internal perisporium of third hole.

Above-mentioned solid fixedring 8 not only can be used for spacingthrust coil 6, still locatesradial stator core 4 clamp between two solid fixedring 8 to it is spacing to carry out the axial toradial stator core 4, in order to prevent radial stator core axial float.

In another embodiment, as shown in fig. 4 and 5, the statormagnetic pole 3 includes two halves, and the two halves are connected to enclose the annular statormagnetic pole 3. Specifically, the two halves are afirst half 33 and asecond half 34, and thefirst half 33 and thesecond half 34 are connected by bolts, it should be noted that at least one of thefirst half 33 and thesecond half 34 may be made into a split structure to meet the installation requirement.

In other embodiments, as shown in fig. 6, thestator pole 3 may be a unitary structure.

Further, as shown in fig. 7, the composite magnetic suspension bearing 100 further includes aspacer ring 9, and the twostator poles 3 are connected by thespacer ring 9. In this embodiment, thespacer ring 9 is fixedly sleeved outside thepermanent magnet ring 5, preferably, thepermanent magnet ring 5 is in interference fit with thespacer ring 9, thepermanent magnet ring 5 is in interference fit with theradial stator core 4, and thespacer ring 9 connects the secondmagnetic poles 32 of the two statormagnetic poles 3. Specifically, the inner peripheral wall of thespacer ring 9 is provided with an installation ring groove, one end of thepermanent magnet ring 5 is inserted into the installation ring groove, and thepermanent magnet ring 5 is axially limited by using two opposite side walls of the installation ring groove.

Thespacer ring 9 can not only connect the twostator poles 3, but also define the radial position of thepermanent magnet ring 5 and theradial stator core 4. The radial air gap between theradial stator core 4 and the rotor core 1 can be adjusted by limiting the depth of the mounting ring groove, and the size of the radial air gap can be determined according to the calculation of the radial load of the bearing; the axial air gap between thestator pole 3 and the rotor core 1, which can be calculated from the bearing axial load, can also be adjusted by using spacer rings 9 of different axial lengths.

Further, as shown in fig. 8, thepermanent magnet ring 5 is an integral structure. In other embodiments, as shown in fig. 9, thepermanent magnet ring 5 may also be a circular ring structure surrounded by a plurality of permanent magnets which are sequentially connected in the circumferential direction, and the plurality of permanent magnets are distributed at equal intervals in the circumferential direction.

As shown in fig. 10, the embodiment further provides a magnetic suspension bearing system, which includes arotating shaft 300 and the compositemagnetic suspension bearing 100.

Further, the magnetic suspension bearing system further includes a radial magnetic suspension bearing 200 sleeved outside therotating shaft 300, and the composite magnetic suspension bearing 100 and the radial magnetic suspension bearing 200 are disposed at two axial ends of therotating shaft 300. Specifically, X-and Y-radial support and Z-axial support are provided by the compositemagnetic bearing 100; and radial support in the X direction and the Y direction is provided through the radial magnetic suspension bearing 200, so that support and control of a five-axis system are realized.

In the embodiment, an axial magnetic suspension bearing and a radial magnetic suspension bearing are integrated to form the composite magnetic suspension bearing 100, and a radial magnetic suspension bearing 200 is combined to realize the support and control of a five-axis system so as to realize the stability control of the rotor suspension, shorten the axial size of a motor adopting the magnetic suspension bearing system, be beneficial to improving the dynamic characteristic of the rotor, eliminate the electric power loss of a generated bias magnetic field, reduce the heat productivity of the bearing, consume less power and simplify the control system of the compositemagnetic suspension bearing 100. The dynamic characteristic of the rotor is a critical rotation speed of the rotor.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Claims (10)

1. A composite magnetic bearing mounted on a rotating shaft (300), comprising:

the rotor core (1) and the thrust discs (2) positioned on two axially opposite sides of the rotor core (1) are fixedly sleeved outside the rotating shaft (300);

the stator magnetic poles (3) are arranged on one side, back to the rotor core (1), of each thrust disc (2), and the stator magnetic poles (3) are axially arranged at intervals with the thrust discs (2);

the radial stator core (4) is sleeved outside the rotor core (1) and is arranged at a radial interval with the rotor core (1), four salient poles (41) which are uniformly distributed in the circumferential direction are arranged on the radial stator core (4), a radial stator coil (7) is wound on each salient pole (41), and a thrust coil (6) is arranged on one side, facing the radial stator core (4), of each stator magnetic pole (3);

the permanent magnet ring (5) is fixedly sleeved outside the radial stator iron core (4);

the two stator magnetic poles (3) are connected through the spacing ring (9), and the spacing ring (9) is fixedly sleeved outside the permanent magnet ring (5);

stator magnetic pole (3) with it is equipped with solid fixed ring (8) to press from both sides between radial stator core (4), thrust coil (6) be spacing in gu fixed ring (8), stator magnetic pole (3) spacer ring (9) permanent magnetic ring (5) with in the installation space that radial stator core (4) enclose.

2. Composite magnetic bearing according to claim 1, characterized in that the permanent magnet ring (5) is an interference fit with the spacer ring (9) and/or the permanent magnet ring (5) is an interference fit with the radial stator core (4).

3. Composite magnetic bearing according to claim 1, characterized in that the stator poles (3) are of one-piece construction.

4. Composite magnetic bearing according to claim 1, characterized in that the stator pole (3) comprises a first pole (31) and a second pole (32), one end of the first pole (31) is connected to the second pole (32), and the other end of the first pole passes through the second pole (32) and faces the rotor core (1) and is spaced from the rotor core (1).

5. Composite magnetic bearing according to claim 1, characterized in that said stator poles (3) comprise two halves, which are connected to enclose said stator poles (3) in a circular ring.

6. Composite magnetic bearing according to claim 1, characterized in that it further comprises a displacement detection unit (10) for detecting axial and radial displacements of the rotating shaft (300).

7. Composite magnetic bearing according to claim 1, characterized in that the permanent magnet ring (5) is of one-piece construction.

8. Composite magnetic bearing according to claim 1, characterized in that the permanent magnet ring (5) is a circular ring structure surrounded by a plurality of permanent magnets which are connected in sequence in the circumferential direction.

9. A magnetic bearing system, characterized in that it comprises a composite magnetic bearing (100) according to any of claims 1 to 8.

10. The magnetic suspension bearing system of claim 9, further comprising a rotating shaft (300) and a radial magnetic suspension bearing (200) sleeved outside the rotating shaft (300), wherein the composite magnetic suspension bearing (100) and the radial magnetic suspension bearing (200) are disposed at two axial ends of the rotating shaft (300).

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