CN1307375C

CN1307375C - Low watt consumption permanent magnet offset external rotor hybrid radial magnetic bearing

Info

Publication number: CN1307375C
Application number: CNB2005100868320A
Authority: CN
Inventors: 房建成; 孙津济; 马善振
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2005-11-10
Filing date: 2005-11-10
Publication date: 2007-03-28
Anticipated expiration: 2025-11-10
Also published as: CN1752471A

Abstract

Low power consumption permanent magnet bias external rotor hybrid radial magnetic bearing, composed of rotor core, permanent magnet, stator core, excitation coil, air gap, second air gap, 8 stator core poles in X, Y positive and negative directions The magnetic poles are surrounded by excitation coils. Four permanent magnets are embedded between the two stator core poles and placed at 90 degrees on the circumference of the stator. There is a certain gap between the outer surface of the stator core and the inner surface of the rotor core to form Air gap, the second air gap is formed between the two stator cores and the permanent magnet, and the permanent magnet forms a bias magnetic field in the X and Y directions through the stator core poles. The disadvantage of large axial size of the bearing has the advantages of small size, low power consumption, reliable performance, and good control.

Description

A kind of low watt consumption permanent magnet offset external rotor hybrid radial magnetic bearing

Technical field

The present invention relates to a kind of non-contact magnetically suspension bearing, particularly a kind of volume permanent magnet offset external rotor radial magnetic bearing little, low in energy consumption can be used as the contactless support of rotary component in the astrovehicles such as satellite.

Background technique

Magnetic suspension bearing divides pure electromagnetic type and permanent magnet bias to power up the hybrid magnetic suspension bearing of magnetic control system, the former uses, and electric current is big, power consumption is big, permanent magnet bias powers up the hybrid magnetic suspension bearing of magnetic control system, main bearing capacity is born in the magnetic field that permanent magnet produces, electromagnetism magnetic field provides auxiliary adjusting bearing capacity, thereby this bearing can reduce to control electric current greatly, reduces the wastage.But present permanent magnet offset external rotor radial magnetic bearing structure, some is on the basis of common radial magnetic bearing, on electromagnetic circuit to placing permanent magnet, the magnetic flux that control coil produced will pass permanent magnet like this, because the permanent magnet magnetic resistance is very big, thereby control coil will produce certain electromagnetism magnetic flux and need bigger exciting curent, and this obviously can increase the power consumption of bearing; Certain structures is that permanent magnet is directly linked to each other with stator lasmination is unshakable in one's determination, and permanent magnetic circuit can lose too much magnetomotive force when vertically passing stator core like this, thereby can weaken the suction of permanent magnet to rotor shaft greatly; Also some structure is that permanent magnet is linked to each other with laminated core by magnetic guiding loop, the electricity magnetic excitation circuit forms the loop through laminated core, the permanent magnetism magnetomotive force can not produce loss in laminated core like this, electric magnetic excitation circuit can not passed through permanent magnet itself yet simultaneously, but its plane, permanent magnetic circuit place of the radial direction magnetic bearing of this structure is vertical mutually with plane, electric magnetic excitation circuit place, thereby can cause axial length longer, so can not satisfy little, the lightweight purposes of the desired volume of astrovehicle such as satellite, space station.Chinese patent application 200510086223.5, as shown in Figure 1, Chinese patent application 200510086213.1, as shown in Figure 2, two kinds of external rotor radial magnetic bearings have been provided, although the permanent magnetic circuit of these two kinds of structures and electric magnetic excitation circuit coplane, can accomplish that axial length is short, but its stator core magnetic pole is 8 is distributed in circumference, and the power on magnetic bearing X and the Y direction be by these 8 magnetic poles make a concerted effort constitute, 45 degree because 8 magnetic pole of the stator are separated by successively, thereby+X,-X, + Y and-produce certain bearing capacity on the Y direction, just need to feed in each magnetic pole of the stator coil bigger electric current and just can realize, thereby cause power consumption to increase.

Summary of the invention

Technology of the present invention is dealt with problems and is: overcome the deficiencies in the prior art, provide that a kind of volume is little, in light weight, low in energy consumption, a kind of low watt consumption permanent magnet offset external rotor hybrid radial magnetic bearing of convenient processing and manufacture.

Technical solution of the present invention is: a kind of low watt consumption permanent magnet offset external rotor hybrid radial magnetic bearing, form by rotor core, permanent magnet, stator core, field coil, 8 stator core magnetic poles have been formed the magnetic pole on the positive negative direction of X, Y, wherein 4 permanent magnets are embedded between two stator core magnetic poles, and be 90 degree and place, stator core outer surface and rotor core internal surface leave the gap, form air gap, form interstice between permanent magnet and the stator core, and by the bias magnetic field on stator core magnetic pole formation X, the Y direction.

The principle of such scheme is: permanent magnet provides permanent magnet bias magnetic field to magnetic bearing, bear the suffered radial force of magnetic bearing, regulating action is played in the magnetic field that field coil produced, be used for changing the power in magnetic field on X, the Y direction, keep magnetic bearing rotor air gap even, and make rotor obtain contactless support.Shown in Fig. 1 solid arrow, permanent magnetic circuit of the present invention is: magnetic flux is from the permanent magnet N utmost point, by stator core, one end+Y direction air gap, rotor core, get back to the permanent magnet S utmost point to the other end+Y direction air gap, stator core, form the main magnetic circuit of magnetic suspension bearing; Shown in Fig. 1 dotted arrow, electric magnetic excitation circuit path is: electro-magnetic flux is from the stator core magnetic pole the on+Y direction, constitute the closed-loop path through air gap, rotor core to air gap, stator core magnetic pole and the interstice of the other end+Y direction of one end+Y direction.Guaranteed that so not only electric excitatory magnetic circuit is not by permanent magnet inside, reduced the magnetic resistance of electric excitatory magnetic circuit, reduced exciting curent, and then reduced the power consumption of bearing, make again simultaneously permanent magnetic circuit in arbitrary radial cross section with electric magnetic excitation circuit coplane, reduced the axial dimension of radial direction magnetic bearing greatly, 8 stator core magnetic poles are at+X,-X, + Y and-the Y direction on compact the distribution, can make that the required electric current of the onesize bearing capacity of generation is littler, in addition, winding method is adopted in stator core, can adopt high saturation magnetic induction, the soft magnetic material that high resistivity and lamination thickness are littler is made stator core, this can make that producing the onesize required stator core volume of bearing capacity reduces, because core-lamination stack thickness is little, so the eddy current loss that produces in the iron core can reduce greatly.

The present invention's advantage compared with prior art is: the present invention is owing to adopt permanent magnetic field as bias magnetic field, compare with the traditional electrical magnetic bearing and to have eliminated the bias current that in coil current, accounts for fundamental component, reduced winding copper loss and the loss of control power amplifier, so power consumption is very low.Compare with existing permanent magnet biased magnetic bearing, its permanent magnetic circuit of permanent magnet offset external rotor radial magnetic bearing of the present invention and electric excitatory magnetic circuit coplane in arbitrary radial cross section, thereby can reduce the axial dimension of radial direction magnetic bearing greatly, and then reduce the volume of radial direction magnetic bearing; Again because 8 stator cores compact distribution on X and Y direction, can be littler so that produce the electric current of the required field coil of onesize bearing capacity, adopt winding method because of stator core again, can adopt high saturation magnetic induction, high resistivity, soft magnetic material that lamination thickness is littler to make stator core, this can make that producing the onesize required stator core volume of bearing capacity reduces, because core-lamination stack thickness is little, so the eddy current loss that produces in the iron core can reduce greatly.

Description of drawings

Fig. 1 is a kind of existing permanent magnet offset external rotor radial magnetic bearing longitudinal section view;

Fig. 2 is another kind of existing permanent magnet offset external rotor radial magnetic bearing longitudinal section view;

Fig. 3 is a low watt consumption permanent magnet offset external rotor hybrid radial magnetic bearing longitudinal section view of the present invention.

Embodiment

As shown in Figure 3, for the present invention is made up of rotor core 1, permanent magnet 2, stator core 3, field coil 5,8 stator core 3 magnetic poles form the stator core magnetic pole on X, the Y direction, and are wound with field coil around it.4 permanent magnets 2 are positioned between two stator cores 3, and are 90 degree distribution placements.Stator core 3 outer surfaces and rotor core 1 internal surface leave certain clearance (being generally 0.2-0.4mm) and form air gap 4, interstice between permanent magnet 2 and the stator core also should be a bit larger tham the length of 2 times of air gaps 4, to reduce the magnetomotive loss of permanent magnet, permanent magnet 2 is by the bias magnetic field on stator core 3 magnetic poles formation X, the Y direction.When concrete the application, permanent magnet offset external rotor radial magnetic bearing of the present invention should use in pairs.

The used rotor core 1 of the present invention can form with magnetic property good electric thin steel sheet such as magnetic material punching presses such as electrical pure iron, electrical steel plate DR510, DR470, DW350,1J50,1J79 or the silicon steel thin belt system of changing; Stator core 3 can adopt high saturation magnetic induction, soft magnetic material such as coilings such as silicon steel thin belt, amorphous that lamination thickness is little to form; The material of permanent magnet 2 is good rare-earth permanent magnet of magnetic property or ferrite permanent magnet, and permanent magnet 2 is a parallel magnetization, and paint-dipping drying forms after the good electromagnetic wire coiling of field coil 5 usefulness conductions.

Claims

1. Low power consumption permanent magnet bias external rotor hybrid radial magnetic bearing, characterized in that it consists of rotor core (1), permanent magnet (2), stator core (3), excitation coil (5), and 8 stators The magnetic poles of the iron core (3) form the magnetic poles in the positive and negative directions of X and Y. Among them, four permanent magnets (2) are embedded between the two stator core (3) magnetic poles, and are placed at 90 degrees on the circumference of the stator. The stator core (3) There is a gap between the outer surface and the inner surface of the rotor core (1), forming an air gap (4), forming a second air gap (6) between the permanent magnet (2) and the stator core (3), and passing through the stator core (3) The magnetic poles form a bias magnetic field in the X and Y directions.

2. The low power consumption permanent magnet bias outer rotor hybrid radial magnetic bearing according to claim 1, characterized in that: said permanent magnets (2) are magnetized in parallel.

3. The low power consumption permanent magnet bias outer rotor hybrid radial magnetic bearing according to claim 1, characterized in that: the air gap formed between the outer surface of the stator core (3) and the inner surface of the rotor core (1) (4) is 0.2-0.4mm.

4. The low power consumption permanent magnet bias outer rotor hybrid radial magnetic bearing according to claim 1, characterized in that: the length of the second air gap (6) is greater than twice the length of the air gap (4) .

5. The low power consumption permanent magnet bias outer rotor hybrid radial magnetic bearing according to claim 1, characterized in that: the permanent magnet (2) is made of rare earth permanent magnet material or ferrite permanent magnet material .

6. The low power consumption permanent magnet bias outer rotor hybrid radial magnetic bearing according to claim 1, characterized in that: the rotor core (1) is made of materials with good magnetic permeability and stamped along the axial direction become. The stator core (3) is made of a wound core, and the material can be made of silicon steel thin strip or amorphous with high saturation flux density.