CN100494707C

CN100494707C - Three magnetic pole permanent magnetism bias radial magnetic bearing

Info

Publication number: CN100494707C
Application number: CNB2007101351838A
Authority: CN
Inventors: 赵旭升; 邓智泉; 王晓琳; 梅磊; 王晓刚
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2007-11-07
Filing date: 2007-11-07
Publication date: 2009-06-03
Anticipated expiration: 2027-11-07
Also published as: CN101158374A

Abstract

A permanent magnetic offset radial magnetic bearing with three magnetic poles, belonging to mixed magnetic bearing in the magnetic bearings, comprises a radial stator (1), a control winding (2), a cirque permanent magnet (5) radially filled with magnet, an exterior magnetic pole iron center (6) and a rotor (3) sleeved with a rotor iron center (4). The permanent magnetic offset radial magnetic bearing utilizes the cirque permanent magnet radially filled with the magnet to establish a static offset magnetic field; an enclosed magnetic path is formed by the exterior magnetic pole iron center, the rotor iron center and the radial stator; the radial control winding with three magnetic poles produces a control flux to be coincident with an offset flux; radial suspension with two degrees of freedom is implemented by the three/two commutation principle of an AC motor; with the advantages of simple structure, small volume, light weight, low power consumption and small axial space occupied, the invention has wide applicable prospects in the high-speed applicable sites such as flywheel energy storage, air conditioner compressor, turbomolecular pump, etc.

Description

The permanent magnet offset radial magnetic bearing of three magnetic poles

One, technical field

Three magnetic pole permanent magnet offset radial magnetic bearings of the present invention belong to the hybrid magnetic bearing in the magnetic bearing.

Two, background technique

Magnetic suspension bearing abbreviates magnetic bearing again as, is to utilize the magnetic force between stator and the rotor that rotor is suspended in the space, makes a kind of novel high-performance bearing that does not have Mechanical Contact between stator and the rotor.Owing to there is not contact mechanically between the stator and rotor, so the rotor of magnetic suspension bearing can reach very high running rotating speed, and have advantages such as mechanical wear is little, energy consumption is low, the life-span is long, unlubricated, pollution-free, be particularly suitable for special applications such as high speed, vacuum and super cleaning.

At present, the mode that magnetic bearing provides according to magnetic force is divided into following several: first kind is active magnetic bearings, there is bias current in this magnetic bearing coil, so that bias magnetic field to be provided, superpose with the biasing magnetic flux by the control electric current control magnetic flux that the control winding produces of flowing through, thereby produce controlled suspending power, volume, weight and power consumption are all bigger.Second kind is passive magnetic bearing, the suspending power of this magnetic bearing is provided by permanent magnet fully, and its required controller is simple, and the suspension power consumption is little, but rigidity and damping are all less, only generally apply in one direction supporting object or alleviate the load that acts on the traditional bearing.The third is a hybrid magnetic bearing, the electromagnet that this magnetic bearing adopts permanent-magnet material to substitute in the active magnetic bearings produces bias magnetic field, the just balanced load that electromagnet provides or the controlling magnetic field of interference, greatly reduce the power loss that produces because of bias current, the required Number of ampere turns of electromagnet is half of active magnetic bearings, dwindle the volume of magnetic bearing, alleviated its weight, and improved bearing capacity.

The permanent magnet offset radial magnetic bearing structural type of research is divided into different pole and same polarity structure in the world at present, different pole structure axial length can be done shortlyer, but can produce hysteresis loss, and the magnetic bearing hysteresis loss of the structure of same polarity reduces greatly, but common same polarity magnetic bearing structure is complicated, and required control winding is many, and power consumption is big, the axial space that takies simultaneously is bigger, is unfavorable for the raising of rotor critical speed.

Three, summary of the invention

The objective of the invention is to propose a kind of simple in structure, volume is little, and is in light weight, low in energy consumption, the same polarity permanent magnet offset radial magnetic bearing that axial occupation space is little.

Three magnetic pole permanent magnet offset radial magnetic bearings of the present invention comprise stator module and rotor assembly.It is characterized in that: described stator module, comprise radial stator, control winding, annular permanent magnet and external magnetic poles iron core, wherein radial stator is the radial stator of three field structures, on three magnetic poles of radial stator, be wound with the control winding, annular permanent magnet is mounted on the outer end of radial stator, the external magnetic poles iron core is sleeved on the cylindrical of radial stator, and its interior edge face contacts with the annular permanent magnet outer end.Described rotor assembly comprises rotor and rotor core, and rotor core is sleeved on the rotor, places in radial stator and the external magnetic poles iron core.Its basic functional principle (is example with the Vertical direction) is: be wound with i.e. three phase windings radially of three-phase control winding on the radial stator iron core, adopt three-phase inverter that the control electric current is provided, when being subjected to a downward disturbing force, rotor departs from the equilibrium position, displacement transducer detects the displacement amount that rotor departs from its reference position, controller is transformed into control signal with this displacement signal, three-phase inverter is transformed into the control electric current with this control signal again, in the three-phase electromagnetic coil, produce the biasing magnetic flux stack in control magnetic flux and the radial air gap, three/two principle of coordinate transformation based on AC motor produce synthetic unipolar flux upwards, make rotor be returned to the equilibrium position.In like manner, no matter rotor is subjected to upwards, to the right or disturbing force left, and the degenerative permanent-magnetic biased axial radial magnetic bearing in band position is by the electric current in the controller control exciting winding, and the size of regulating air-gap flux can keep rotor in the equilibrium position all the time.

Permanent magnet offset radial magnetic bearing of the present invention, utilize the annular permanent magnet of a radial magnetizing to set up quiescent biasing magnetic field, by the external magnetic poles iron core, rotor core and radial stator form closed magnetic circuit, radial stator and three control windings of only needing one three magnetic pole, with respect to traditional radial direction magnetic bearing, having reduced a magnetic pole and one control winding simplifies the structure, dwindled volume and weight, reduced by a magnetic bearing switch power amplifier, reduced the bearing power consumption, and has short axial space, at flywheel energy storage, air condition compressor, high speed applications such as turbomolecular pump have broad application prospects.

Four, description of drawings

Fig. 1 is the permanent magnet offset radial magnetic bearing structural plan schematic representation of three magnetic poles.

Label title among Fig. 1: 1, radial stator.2, control winding.3, rotor.4, rotor core.5, annular permanent magnet.6, external magnetic poles iron core.

Fig. 2 is the permanent magnet offset radial magnetic bearing schematic diagram of three magnetic poles.

Label title: A is an air gap among Fig. 2, and solid line is represented the permanent magnet bias magnetic flux, and single dotted line represents radially to control the control magnetic flux that winding produces.

Five, embodiment

Fig. 1 is three magnetic pole permanent magnet offset radial magnetic bearing structural representations of the present invention, radial stator 1 among the figure is formed by silicon steel plate stacking, be three field structures, on three magnetic poles, be wound with control winding 2, annular permanent magnet 5 is mounted on the position of the outside of radial stator 1, external magnetic poles unshakable in one's determination 6 is made for electrical pure iron, for further reducing magnetic hysteresis and eddy current loss, rotor core 4 is formed by silicon steel plate stacking, external magnetic poles iron core 6 is sleeved on radial stator 1 cylindrical, its interior edge face contacts with annular permanent magnet 5, and the rotor core 4 that is sleeved on the rotor 3 places in stator 1 and the external magnetic poles iron core 6.The biasing magnetic flux that annular permanent magnet produces constitutes the loop through external magnetic poles iron core, radial air gap A, rotor core, radial air gap and radial stator successively, shown in the solid line of Fig. 2.The control magnetic flux that is produced by the control winding only passes through radial air gap, without air gap A.Shown in the dotted line of Fig. 2.

Claims

1, a kind of permanent magnet offset radial magnetic bearing of three magnetic poles, comprise stator module and rotor assembly, described stator module, comprise radial stator (1), control winding (2), annular permanent magnet (5) and external magnetic poles iron core (6), annular permanent magnet (5) is mounted on the outer end of radial stator (1), the interior edge face of radial stator (1) contacts with annular permanent magnet (5) outer end, described rotor assembly comprises rotor (3) and rotor core (4), rotor core (4) is sleeved on the rotor (3), place in radial stator (1) and the external magnetic poles iron core (6), it is characterized in that: radial stator (1) is the radial stator of three field structures, on three magnetic poles of radial stator (1), be wound with control winding (2), described external magnetic poles iron core (6) is one-sided pole core, is sleeved on the cylindrical of radial stator (1).