CN103591138A - Homopolar monocycle hybrid magnetic bearing - Google Patents

Abstract

The invention relates to a homopolar monocycle hybrid magnetic bearing, and solves the problem that a magnetic pole of an existing hybrid magnetic bearing only has a supporting property, the dynamic allocation is not preformed, and a rotor sensor needs to be mounted. The bearing comprises a stator, a rotor and a control system, wherein the stator comprises a bearing shell, at least more than 6 groups of electromagnets in an even number manner as well as permanent magnet combining blocks the quantity of which corresponds to that of the electromagnets, wherein the permanent magnet combining blocks and the electromagnets are alternately uniformly arranged on the inner side of an assembling ring at intervals, and the assembling ring is fixed in the bearing shell. The homopolar monocycle hybrid magnetic bearing provided by the invention has the advantages that the separation of the magnetic pole support and the damping property is realized, the magnetic pole property is subjected to dynamic allocation, the balance of the magnetic bearing is good, the structure is reasonable, the installation and use on the space are convenient, the detection of rotor displacement adopts a self-sensing technology, any rotor displacement sensor does not need to be placed in the bearing, the stability of a rotor system is guaranteed, the cost is reduced, the space does not need to occupy, and the maintenance and calibration are simple.

Description

A kind of same polar form monocycle hybrid magnetic bearing

Technical field

The present invention relates to a kind of non-contact magnetically suspension bearing, especially relate to and a kind ofly can carry out polymorphic distribution, balance better with polar form monocycle hybrid magnetic bearing to magnetic pole.

Background technique

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

Magnetic suspension bearing is according to the presentation mode of magnetic force, can be divided into active magnetic bearings (AMB, Active Magnetic Bearing), passive magnetic bearing (PMB, Passive Magnetic Bearing) and hybrid magnetic bearing (HMB, Hybrid Magnetic Bearing).

Hybrid magnetic bearing utilizes the magnetic field that permanent magnet produces to replace the quiescent biasing magnetic field that in Active Magnetic Suspending Bearing, electromagnet produces, be called again permanent magnet biased magnetic bearing, there is the power consumption that reduces power amplifier, reduce the number of turn of electromagnet, the advantages such as volume of dwindling magnetic bearing; Its electromagnetic coil just becomes control coil simultaneously, possesses control performance more flexibly, and supporting power amplifier also can further reduce volume, reduce power consumption with it.

There are at present many hybrid magnetic bearings, its general structure comprises stator, rotor, 3 to 4 magnetic poles are generally only set in same circumferential plane on stator, by controlling the elastic force of these magnetic poles, regulate the balance of rotor, but in rotation process, may there is gyro phenomenon, especially nutating mode in rotor, cause magnetic bearing uneven, and the magnetic pole of existing magnetic bearing generally all only shows as bearing characteristics, be difficult for regulating, even cause magnetic bearing to damage.Also have some hybrid magnetic bearings, its permanent magnet and electromagnet mounting structure are arranged unreasonable, and as permanent magnet is horizontally installed between electromagnet or is arranged on electromagnet rear portion, this has increased the size of bearing, the installation on inconvenient space and use.Existing hybrid magnetic bearing all will be placed rotor displacement sensor in bearing in addition, to meet testing requirement, but exists sensor cost high, installs and connect up to take up space, and maintenance and orientation ratio are more difficult.

If the patent No. is 201220379576.X, name is called a kind of Chinese utility model patent of radial direction magnetic bearing current vortex sensor integral structure, it comprises that four paths are to the permanent magnet biased hybrid magnetic bearing of displacement sensor probe, control rotor suspension, this permanent magnet biased hybrid magnetic bearing comprises that two-layer magnetic pole and middle permanent magnet form, each magnetic pole has four, and 90 degree of being separated by same circumference distribute.This magnetic bearing regulates the balance of rotor by the supporting force on control magnetic pole.Just there is above-mentioned shortcoming in this patent: 3 to 4 magnetic poles are generally only set in same circumferential plane on stator, by controlling the elastic force of these magnetic poles, regulate the balance of rotor, but may there is gyro phenomenon in rotor in rotation process, especially nutating mode, cause magnetic bearing uneven, be difficult for regulating, even cause magnetic bearing to damage; In bearing domestic demand, place rotor displacement sensor, exist sensor cost high, installation and wiring take up space, and maintenance and orientation ratio are more difficult.

Summary of the invention

The present invention solves the existing magnetic pole of existing hybrid magnetic bearing only to have supporting attribute, can not carry out dynamic assignment, the problem that easily occurs gyroscopic effect, a kind of a plurality of magnetic poles that have are provided, can support and damping attribute dynamic assignment magnetic pole, balance is better with polar form monocycle hybrid magnetic bearing.

Second goal of the invention of the present invention is to solve existing hybrid magnetic bearing unreasonable structure, and the problem of installing and using on inconvenient space, provides a kind of same polar form monocycle hybrid magnetic bearing rational in infrastructure, that size is little, easy for installation.

Another goal of the invention of the present invention is to have solved existing hybrid magnetic bearing rotor displacement sensor need to be set in bearing, cost is high, installation and wiring take up space, and the problem of maintenance and calibration difficulties, provides a kind of same polar form monocycle hybrid magnetic bearing without sensor installation.

Above-mentioned technical problem of the present invention is mainly solved by following technical proposals: a kind of same polar form monocycle hybrid magnetic bearing, comprise stator, rotor and control system, stator comprises bearing case, at least n organizes electromagnet, and the permanent magnet combination piece corresponding with electromagnet quantity, n=6+2k wherein, k=0,1,2,3 ... described permanent magnet combination piece and electromagnet alternate, and to be arranged on assembling circle inner side upper at even interval, and assembling circle is fixed in bearing case.In the present invention, permanent magnet combination piece is provide the foundation support stiffness, i.e. bearing static stiffness of whole bearing.A plurality of electromagnets are around forming electromagnetism ring array, and an electromagnet forms a magnetic pole, has formed many magnetic poles.Electromagnetic pole changes generation support stiffness for width of air gap and shows as elastic force, and can change and produce corresponding damping spinner velocity.Control electric current and can make the vanishing of pole supports rigidity, thereby show as electromagnetic damping completely, therefore can control respective poles and show as support stiffness magnetic pole or supporting damping magnetic pole.Adopt even number set electromagnets more than at least 6 groups, by the DYNAMIC DISTRIBUTION to magnetic pole, make some magnetic poles show as support stiffness magnetic pole like this, some magnetic poles show as damping magnetic pole.Adopt many magnetic poles can carry out DYNAMIC DISTRIBUTION, these are different from the magnetic bearing of general four magnetic poles, and the existing magnetic pole that shows as support stiffness of the present invention, also has the magnetic pole that shows as electromagnetic damping, and support stiffness and damping are separated, and realize both independent.When keeping balancing rotor, can also effectively suppress by the magnetic pole of electromagnetic damping the nutating mode in strong gyroscopic effect, obviously reduce the vibration turning, make the balance of magnetic bearing better, meet the specific (special) requirements of highi degree of accuracy processing.

For controlling bearing supporting force and damping force is in same plane radially, and can dynamically adjust, independent manipulation, with respect to supporting in bearing in the past and damping, control and separate in different manipulation planes, axial dimension is obviously reduced.

As a kind of preferred version, described permanent magnet combination piece consists of the combination of three permanent magnets, and the N utmost point of the permanent magnet in the middle of being positioned at is towards bearing centre, is positioned at the N utmost point of permanent magnet of both sides towards middle permanent magnet.Three permanent magnets form Haier's Bake discritized array by this arrangement mode, this structure makes permanent magnet surfaces magnetic induction intensity larger, the magnetic induction intensity that surpasses monolithic magnet far away, the whole annular array that permanent magnet combination piece forms like this shows an interior side magnetic intensity obviously to be strengthened, an outer side magnetic intensity obviously weakens, and magnetic field strengthens side provides larger bearing capacity for magnetic bearing.

As a kind of preferred version, described electromagnet comprises the magnetic pole head that is arranged on both sides places, and coil is on magnetic pole head, and the polarity that every group of electromagnet is positioned at the magnetic pole head in same circumferential plane is identical.The features such as these some groups of electromagnets form an annular array, and the polarity that is positioned at the magnetic pole head in same circumferential plane on annular array is identical, have formed with polar form structure, have system power dissipation low with polar form structure, and radial dimension is little.

As a kind of preferred version, described assembling circle is all arranged at intervals with wedge slot on inner side, this wedge slot is up-narrow and down-wide dovetail structure, and described permanent magnet combination piece and electromagnet are all the up-narrow and down-wide trapezium structures matching with wedge slot, and permanent magnet combination piece and electromagnet are inserted in wedge slot.Adopt assembling circle assembling permanent magnet combination piece and electromagnet, and adopt wedge-like engagement mode, make to assemble more convenient, and these permanent magnet combination pieces and electromagnet interval are arranged in assembling circle, formed a single ring architecture, having realized all permanent magnet combination pieces and electromagnet is all distributed on the same face on assembling circle inner side surface, the axial dimension of whole bearing is significantly reduced, installation and use on more convenient and space, the structure of monocycle can utilize a plurality of bearing fits to be applicable to various types of rotating shafts in addition, single ring architecture makes the production standard of bearing, engineering application area is more extensive.Assembling circle adopts NULL to make, and makes that magnet pieces is independent of one another, magnetic circuit is independent of each other.

As a kind of preferred version, on described bearing case inwall, near a side ports place, be provided with a circle and stop edge, described assembling circle is stuck in and stops along upper after being fit in bearing case, in assembling, enclose on the other end that relatively stops edge and be pressed with retaining ring, retaining ring and bearing case inwall interference fit are connected with bearing (ball) cover by engage thread outside the two ends of bearing case.This Standard is convenient and swift, more convenient production on a large scale.

As a kind of preferred version, described control system comprises the switch pair corresponding with electromagnet quantity, power amplifier driver, DSP digital signal processor, switch is to being connected on power supply, switch is to comprising the switch of two series connection, a switch pair of the corresponding connection of each electromagnet, coil one end ground connection of electromagnet, the other end is connected to its corresponding switch between two switches connections, described power amplifier driver control connects each switch pair, DSP digital signal processor is connected with power amplifier driver, DSP digital signal processor is also connected respectively on the tie point of the coil winding of each electromagnet and each switch pair and power cathode.Electromagnet coils adopts heterogeneous y connection, uses ballast resistor network struction central potential, makes each independent control mutually, for controlling decoupling algorithm, provides convenience.Switch is to being connected between DC electrical source both positive and negative polarity, positive voltage V _dC+with negative voltage V _dC-

Given current load is on the coil of electromagnet, power amplifier driver sends and drives each switch of SC sigmal control to work, the difference of the voltage duty cycle by control switch power tube and the different electric current of mean value in the generation cycle, thereby the size of current on control coil.The driving mode of the pwm signal of power amplifier driver can have two kinds: the first produces the modulation of pyramidal wave by sine wave; The initial phase of carrier wave sine wave makes magnetic pole phase differ successively 60 degree and modulates its operating voltage amplitude to form magnetic field angular force, and this working method is a kind of magnetic force phase transformation bearing that exchanges driving.It two is by its operating current that each phase coil is worked alone, and forms electromagnetic field stable and that capable of dynamic is adjusted, thereby forms magnetic field angular force, and this working method is the magnetic bearing of a kind of direct current or accurate direct drive.The pwm signal of power amplifier driver is wide band by changing frequency coverage that carrier frequency makes pwm signal from low frequency to high frequency, with this, adapts to the operation adjusting from low speed to high speed of magnetic bearing rotor.DSP digital signal processor is connected on the point that each switch pair is connected with power cathode in addition, this point voltage is carried out to collection analysis, so that overcurrent protection to be provided.

As a kind of preferred version, described DSP digital signal processor includes ADC unit and CPU element, and described ADC unit is connected with CPU element,

ADC unit is connected with the coil of each electromagnet, and is connected on the tie point of each switch pair and power cathode, and CPU element is connected with power amplifier driver.ADC unit is to the electric current in each electromagnet coils, and each switch pair gathers with the current value at power cathode tie point place, and the information of these collections is carried out sending to CPU element to process after pattern conversion.The current value that CPU element gathers each electromagnet coils place carries out obtaining rotor shift value and the flexible rate of displacement of each magnetic pole relatively after computing, CPU element is according to positional value and the flexible component analysis rotor oscillation amount of displacement and nutating mode amount situation, and the damping force that judges whether to improve respective poles elastic force and increase respective poles, then CPU element sends instruction to power amplifier driver, by the switch of the corresponding magnetic pole of power amplifier driver control to work, control the size of current on each pole coil, thereby elastic force or damping force on control magnetic pole, simultaneously power amplifier driver also by control switch to work, on each pole coil, produce the required high frequency small-signal of self-sensing.The present invention adopts self-sensing technology to the detection of rotor displacement, inner without placing any rotor displacement sensor, but realize by load high frequency small-signal on coil, this overlaps the working surface of sensor of the present invention and bearing magnetic pole completely, the mode of this self-sensing has realized without phase difference measurements, has guaranteed the stability of rotor-support-foundation system.Power amplifier driver control switch, to produce the required high-frequency signal of self-sensing on coil, also produces the control current signal that electromagnet is controlled, and two signals superpose.

Therefore, the advantage that the present invention has is: adopt many magnetic poles 1., pole supports and damping attribute are separated, realize independent, can carry out dynamic assignment to magnetic pole attribute, can effectively suppress the nutating mode in strong gyroscopic effect, obviously reduce the vibration turning, make the balance of magnetic bearing better, meet the specific (special) requirements of highi degree of accuracy processing; 2. rational in infrastructure, the axial dimension of whole bearing is significantly reduced, installation and use on more convenient and space, and can utilize a plurality of bearing fits to be applicable to various types of rotating shafts, make in addition the production standard of bearing, engineering application area is more extensive; 3.

The detection of rotor displacement is adopted to self-sensing technology, inner without placing any rotor displacement sensor, the working surface of sensor of the present invention and bearing magnetic pole is overlapped completely, realized without phase difference measurements, guaranteed the stability of rotor-support-foundation system, reduced cost, without taking up room, safeguarded and calibrate simple.

Accompanying drawing explanation

Accompanying drawing 1 is a kind of structure exploded perspective view of the present invention;

Accompanying drawing 2 is a kind of cross-sectional view of the present invention;

Accompanying drawing 3 is a kind of electrical block diagrams of control system in the present invention;

Accompanying drawing 4 is a kind of magnetic circuit schematic diagram of permanent magnet combination piece in the present invention;

Accompanying drawing 5 is a kind of schematic flow sheets of controlling method in the present invention;

Accompanying drawing 6 is a kind of simple and easy schematic diagram of 6 magnetic poles in the present invention.

1-bearing case 2-assembling circle 3-permanent magnet combination piece 4-electromagnet 5-magnetic pole head 6-permanent magnet 7-wedge slot 8-retaining ring 9-end cap 10-stops along 11-DSP digital signal processor 12-switch 15-CPU unit, 13-power amplifier driver 14-ADC unit

Embodiment

Below by embodiment, and by reference to the accompanying drawings, technological scheme of the present invention is described in further detail.

Embodiment:

A kind of same polar form monocycle hybrid magnetic bearing of the present embodiment, magnetic bearing includes stator, rotor and control system.As shown in Figure 1, stator includes bearing case 1, is provided with the inner core that electromagnet 4 and permanent magnet combination piece 3 form in bearing case, adopts 6 utmost point magnetic bearings in the present embodiment, and this electromagnet has 6 groups, and what permanent magnet combination piece was corresponding also has 6 groups.On electromagnet, position, both sides is provided with magnetic pole head 5, is wound with coil on magnetic pole head.Permanent magnet combination piece is constituted by three permanent magnets 6, three permanent magnets adopt Haier's Bake discritized array arranging structure, and as shown in Figure 4, permanent magnet top is rotor, the N utmost point of the permanent magnet in the middle of being positioned at is towards the rotor of bearing centre, is positioned at the N utmost point of permanent magnet of both sides towards middle permanent magnet.Permanent magnet combination piece and the electromagnet even interval that alternates is arranged on assembling circle 2 inner sides, assembling circle is all arranged at intervals with wedge slot 7 on inner side, this wedge slot is up-narrow and down-wide dovetail structure, permanent magnet combination piece and electromagnet are all the up-narrow and down-wide trapezium structures matching with wedge slot, and permanent magnet combination piece and electromagnet are inserted in wedge slot.This electromagnet adopts same polar form, at electromagnet, packs into after wedge slot, and the polarity that every group of electromagnet is positioned at the magnetic pole head in same circumferential plane is identical.

As shown in Figure 2, on bearing case 1 inwall, near a side ports place, being provided with a circle stops along 10, assembling circle is enclosed in bearing case, be stuck in and stop along upper, in assembling, enclose on the other end that relatively stops edge and be pressed with retaining ring 8, retaining ring and bearing case inwall interference fit are connected with bearing (ball) cover 9 by engage thread outside the two ends of bearing case.

As shown in Figure 3, control system comprise 6 switches to 12, power amplifier driver 13, DSP digital signal processor 11, DSP digital signal processor includes ADC unit 14 and CPU element 15, ADC unit is connected with CPU element.Switch is to comprising the switch of two series connection, a switch pair of the corresponding connection of each electromagnet, coil one end ground connection of electromagnet, the other end is connected to its corresponding switch between two switches connections, ADC unit is connected respectively in each electromagnet coils, CPU element is connected with power amplifier driver, and power amplifier driver control connects each switch pair.Three switches are to being connected in parallel, and form like this two each and every one six phase switches, by two PWM, are controlled.Between two six phase switches and power cathode, be connected with respectively resistance R samp1 and resistance R samp2, on ADC unit is also connected to respectively between these two six phase switches and power cathode

ADC unit: the electric current in each electromagnet coils is gathered, and the information of these collections is carried out sending to CPU element to process after pattern conversion;

CUP unit: the current value that each electromagnet coils place is gathered carries out obtaining rotor shift value and the flexible rate of displacement of each magnetic pole relatively after computing, CPU element is according to positional value and the flexible component analysis rotor oscillation amount of displacement and nutating mode amount situation, and the damping force that judges whether to improve respective poles elastic force and increase respective poles, then CPU element sends instruction to power amplifier driver, by the switch of the corresponding magnetic pole of power amplifier driver control to work, control the size of current on each pole coil, thereby elastic force or damping force on control magnetic pole, simultaneously power amplifier driver also by control switch to work, on each pole coil, produce the required high frequency small-signal of self-sensing.

The controlling method of magnetic bearing control system is:

Comprise the detection to rotor displacement, the adjusting to magnetic pole elastic force or damping force

The testing process of rotor displacement is: by CPU element, control heterogeneous switch and load high frequency small-signal to each electromagnet coils, on coil, produce the induced current of reaction rotor displacement signal, ADC unit gathers the electric current in each electromagnet coils, be transferred to CPU element, CPU element calculates shift value and the shift transformation amount of the relative rotor of each electromagnet to sample rate current value;

CPU element calculates and to comprise information is carried out to anti-aliasing filter, fft, kalman filtering and Second-Order Discrete TD sample rate current value information.

The detailed process of this calculating is:

A., sampling number N and sample frequency in one or more measuring periods are set

$f_{s\min }=2\·\frac{{\mathrm{\Ω}}_{\max }}{60};$

B. after ADC unit sampling, form discrete sequence i (nT), be denoted as

$i\left(n\right)=i_x\left(n\right)\frac{e^{\mathrm{jn\Ω}}+e^{-\mathrm{jn\Ω}}}{2},$ 2 times of signals of rotating speed are obtained to displacement current signal with low-pass filter signal elimination;

If c. the i (n) under corresponding certain rotating speed Ω is one and take the sequence that rotating speed is the cycle,

$i\left(n\right)=\left\{\begin{array}{cc}{i}_p\left(n\right)& (0\≤N-1)\\ 0& \mathrm{else}\end{array}\right.=i_p{\left(n\right)}_{N}R\left(n\right),$ Wherein N is the cycle under rotating speed Ω correspondence;

D. utilize the frequency displacement character of discrete fourier, obtain the form of the discrete Fourier transform of chief series: I (k)={ I _p(k-l) R _n(k)+I _p(k+l) R _n(k) }/2, wherein

r _n(k) be square pulse;

E. utilize the windowing of kalman wave filter to take out one of them sequence and represent Displacement Sequence, as

I _x(k)＝I _p(k-l)R _N(k)；

2 frequency-doubled signals of rotating speed are obtained to displacement current signal i with low-pass filter signal elimination _x(t);

F. by I _x(k) input discrete second-order differential tracker

do steepest and follow the tracks of, have: $\left\{\begin{array}{c}{z}_1(k+1)=z_1\left(k\right)+h\·z_2\left(k\right)\\ z_2(k+1)=z_2\left(k\right)+\mathrm{h\γ}\·\mathrm{sat}(g\left(k\right),\mathrm{\δ})\end{array}\right.$

Wherein,

δ＝hγ,δ ₁＝hδ,e(k)＝z ₁(k)-I(k),w ₁(k)＝e(k)+h·z ₂(k)

$g\left(k\right)=\left\{\begin{array}{cc}{z}_2\left(k\right)-\mathrm{sgn}\left(w_1\left(k\right)\right)\frac{\mathrm{\γ}(h-\sqrt{\frac{8\left|z_1\left(k\right)\right|}{\mathrm{\γ}}+h^2})}{2},& \left|z_1\left(k\right)\right|>{\mathrm{\δ}}_1\\ z_2\left(k\right)+\frac{z_1\left(k\right)}{h},& \left|z_1\left(k\right)\right|\≤{\mathrm{\δ}}_1\end{array}\right.$

As shown in Figure 5, the adjusting of magnetic pole elastic force or damping force:

CPU element calculates rotor oscillation amount and nutating mode amount by shift value and shift transformation amount, and the vibratory output reference value of vibratory output and setting is compared;

If vibratory output is greater than reference value, according to shift value information exchange, cross in the electromagnet coils that power amplifier driver control shows as elastic force accordingly switch to working state, change the electric current on respective electrical magnet coil, improve the elastic force of respective electrical magnet, until the vibratory output calculating is not more than reference value;

If vibratory output is not more than reference value, the nutating mode amount reference value of nutating mode amount and setting is compared, if nutating mode amount is greater than reference value, by power amplifier driver control, show as accordingly in the electromagnet coils of damping force switch to working state, change the electric current on respective electrical magnet coil, improve the damping force of respective electrical magnet, know that the nutating mode amount calculating is not more than reference value position.

CPU element, by control switch pair, is controlled electric current to each electromagnet coils output, and each electromagnet poles of dynamic assignment shows as supporting or damping characteristic like this.Its dynamic allocation method is as follows: as shown in Figure 6,6 magnetic poles are circumferentially numbered J1, J2, J3, J4, J5, J6 counterclockwise, and 6 each pole combination can show as following form:

(1) 6 utmost point supporting configuration: J1, J2, J3, J4, J5, J6 all show as yielding support attribute.

(2) 6 utmost point damping configurations: J1, J2, J3, J4, J5, J6 all show as elastic damping attribute.

(3) 2+4 configuration:

①

J1, J4 is extremely to showing as damping attribute, J2, J3, J5, J6 is extremely to showing as yielding support attribute.

②

J2, J5 is extremely to showing as damping attribute, J1, J3, J4, J6 is extremely to showing as yielding support attribute.

③

J3, J4 is extremely to showing as damping attribute, J1, J2, J4, J5 is extremely to showing as yielding support attribute.

(4) two triangle 3+3 configurations: J1, J3, J5 is extremely to showing as damping attribute or yielding support attribute, J2, J4, J6 is extremely to showing as yielding support attribute or damping attribute.

In addition, CPU element can also carry out combination collocation to above-mentioned four kinds of configurations, then according to the arrangement setting, by CPU element, controls the control of moving in turn of each magnetic pole.The control strategy that moves in turn is

By (1), (2), (3) (1., 2., 3.), (4) these several configurations are constructed as follows circulation:

A:(1)--->(3)--->(4)--->(1) circulation of moving in turn greatly;

B:(1)--->(3)--->(1) the moving circulation of steamboat;

C:(1)--->(4)--->(1) the moving circulation of steamboat;

D: 1.-→ 2.-→ 3. inside short circle in the situation that of (3) configuration.

Above-mentioned A, B, C, regulation and control state corresponding to tetra-kinds of circulation modes of D, four kinds of circulation modes can be changed mutually under certain condition.

2+4 configuration take below as example, illustrate the control of control system to magnetic pole.

As shown in Figure 6, suppose that J1, J3, J4, J6 show as yielding support power, J2, J5 show as damping force.The relation that magnetic pole is controlled electric current I and electromagnetic force f is as follows,

$f=\frac{{\mathrm{\μ}}_0{\mathrm{SN}}^2{I}^2}{{({2C}_0+L/{\mathrm{\μ}}_r)}^2}\cos \mathrm{\β}$

μ wherein ₀be permeability of vacuum, S is magnetic circuit area, and N is coil turn, and I is coil loading current, C ₀

Be the primary clearance between electromagnet and rotor, L is the length of magnetic path, μ _rit is the relative permeability of magnetic material.

So suppose that the length of magnetic path of each utmost point is identical, at J1 and J4 magnetic pole the electromagnetism on directions X make a concerted effort be:

$f_{x14}=f_{\mathrm{xJ}1}+{\mathrm{<figure-callout\; id="4"\; label="f\; xJ"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">f</figure-callout>}}_{\mathrm{xJ}}={\mathrm{\&mu;}}_0{\mathrm{<figure-callout\; id="2"\; label="SN"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">SN</figure-callout>}}^2\&lsqb;\frac{{I_{J1}}^2}{{({2C}_0-2x\cos +L/{\mathrm{\&mu;}}_r)}^2}-\frac{{{\mathrm{<figure-callout\; id="4"\; label="I\; J"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_J}^2}{{({2C}_0+2x\cos \mathrm{\&beta;}+L/{\mathrm{\&mu;}}_r)}^2}\&rsqb;\cos \mathrm{\&beta;}$

Wherein x is gap variable quantity; By can determine the relation between damping and rotor airgap variation and electric current with co-relation.In like manner can obtain J3 and J6 adopts under differential driving mode in x direction electromagnetism to make a concerted effort to be:

$f_{x36}={\mathrm{<figure-callout\; id="3"\; label="f\; xJ"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">f</figure-callout>}}_{\mathrm{xJ}}+{\mathrm{<figure-callout\; id="6"\; label="f\; xJ"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">f</figure-callout>}}_{\mathrm{xJ}}={\mathrm{\&mu;}}_0{\mathrm{<figure-callout\; id="2"\; label="SN"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">SN</figure-callout>}}^2\&lsqb;\frac{{I_{\mathrm{<figure-callout\; id="3"\; label="J"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">J</figure-callout>}3}}^2}{{({2C}_0-2{\mathrm{<figure-callout\; id="3"\; label="x\; J"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">x</figure-callout>}}_J\cos +L/{\mathrm{\&mu;}}_r)}^2}-\frac{{{\mathrm{<figure-callout\; id="4"\; label="I\; J"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_J}^2}{{({2C}_0+2x_{\mathrm{<figure-callout\; id="6"\; label="J"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">J</figure-callout>}6}\cos \mathrm{\&beta;}+L/{\mathrm{\&mu;}}_r)}^2}\&rsqb;\cos \mathrm{\&beta;}$

Thereby form by J1 J3, J4

, J6 is the control of the balance in x direction as yielding support power, meets rotor dynamics equation:

$m\stackrel{..}{x}=f_{x14}+f_{x36}$

Wherein m is rotor quality.By that analogy, can calculate J1, J3, J4

, J6 is the control of the balance in y direction as yielding support power:

$m\stackrel{..}{y}=f_{x14}+f_{y36}$

And if the gyroscopic effect of rotor is stronger at the moment, particularly nutating mode, J2, the electromagnetic damping power of J5 performance can produce the effect of the nutating of preventing; J2 under differential driving mode, J5 produces electromagnetic force mechanism and meets following equation:

$c\stackrel{.}{y}=f_{y25}$

Wherein $c=\frac{B^2{L}^2}{R}=\frac{1}{R}{\left(\frac{{\mathrm{\&mu;}}_0{\mathrm{\&mu;}}_r\mathrm{NL}}{y}\right)}^2({{\mathrm{<figure-callout\; id="2"\; label="I\; j"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_j}^2-{{\mathrm{<figure-callout\; id="5"\; label="I\; j"\; filenames="HDA0000398101280000011.png,HDA0000398101280000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_j}^2),$ The c is here damping constant,

R is coil resistance.

Can form like this rotor dynamics equation that y direction contains damping:

$m\stackrel{..}{y}+c\stackrel{.}{y}=f_{y14}+f_{y36}+f_{j25}$

In CPU element, be set in the aequum in X and Y-direction; In control procedure, the electric current of corresponding elastic force pole coil is finely tuned, the value of the balance governing equation of directions X and Y-direction is equated with the aequum under normal working, realized balance control.

When rotor-position changes, there is the inclination in rotor direction, magnetic pole in two ends of rotor can detect respectively the variation of air gap between rotor and magnetic pole, but change direction is contrary, when rotor-position is adjusted, on the magnetic pole at two ends, provide respectively the adjustment power supply in respective direction, make rotor-position adjustment sooner, more accurate.

In the present embodiment, with 6 pole axis, holding as example, but be not limited in 6 utmost points, can also be 8 utmost points, 10 utmost points, or the more even number utmost point, and their regulative mode is also with 6 fairly similars, according to describing method above, just can realize, and does not repeat them here.

Specific embodiment described herein is only to the explanation for example of the present invention's spirit.Those skilled in the art can make various modifications or supplement or adopt similar mode to substitute described specific embodiment, but can't depart from spirit of the present invention or surmount the defined scope of appended claims.

Although more used bearing case, assembling circle, permanent magnet combination piece, electromagnet, the first-class term of magnetic pole herein, do not got rid of the possibility of using other term.Use these terms to be only used to describe more easily and explain essence of the present invention; They are construed to any additional restriction is all contrary with spirit of the present invention.

Claims (7)

1. one kind with polar form monocycle hybrid magnetic bearing, comprise stator, rotor and control system, it is characterized in that: stator comprises bearing case (1), at least n organizes electromagnet (4), and the permanent magnet combination piece (3) corresponding with electromagnet quantity, n=6+2k wherein, k=0,1,2,3 ... described permanent magnet combination piece and electromagnet alternate, and to be arranged on assembling circle (2) inner side upper at even interval, assembles to enclose to be fixed in bearing case.

2. a kind of same polar form monocycle hybrid magnetic bearing according to claim 1, it is characterized in that described permanent magnet combination piece (3) is constituted by three permanent magnets (6), the N utmost point of the permanent magnet in the middle of being positioned at is towards bearing centre, is positioned at the N utmost point of permanent magnet of both sides towards middle permanent magnet.

3. a kind of same polar form monocycle hybrid magnetic bearing according to claim 1, it is characterized in that described electromagnet (4) comprises the magnetic pole head (5) that is arranged on place, both sides, coil is on magnetic pole head, and the polarity that every group of electromagnet is positioned at the magnetic pole head in same circumferential plane is identical.

4. according to a kind of same polar form monocycle hybrid magnetic bearing described in claim 1 or 2 or 3, it is characterized in that being all arranged at intervals with wedge slot (7) on described assembling circle (2) inner side, this wedge slot is up-narrow and down-wide dovetail structure, described permanent magnet combination piece (3) and electromagnet (4) are all the up-narrow and down-wide trapezium structures matching with wedge slot, and permanent magnet combination piece and electromagnet are inserted in wedge slot.

5. according to a kind of same polar form monocycle hybrid magnetic bearing described in claim 1 or 2 or 3, it is characterized in that on described bearing case (1) inwall, near a side ports place, being provided with a circle stops along (10), described assembling circle is stuck in and stops along upper after being fit in bearing case, in assembling, enclose on the other end that relatively stops edge and be pressed with retaining ring (8), retaining ring and bearing case inwall interference fit are connected with bearing (ball) cover (9) by engage thread outside the two ends of bearing case.

6. a kind of same polar form monocycle hybrid magnetic bearing according to claim 1, it is characterized in that described control system comprises that the switch corresponding with electromagnet quantity is to (12), power amplifier driver (13), DSP digital signal processor (11), switch is to being connected on power supply, switch is to comprising the switch of two series connection, a switch pair of the corresponding connection of each electromagnet, coil one end ground connection of electromagnet, the other end is connected to its corresponding switch between two switches connections, described power amplifier driver control connects each switch pair, DSP digital signal processor is connected with power amplifier driver, DSP digital signal processor is also connected respectively on the tie point of the coil winding of each electromagnet and each switch pair and power cathode.

7. a kind of same polar form monocycle hybrid magnetic bearing according to claim 6, is characterized in that described DSP digital signal processor (11) includes ADC unit (14) and CPU element (15), and described ADC unit is connected with CPU element,

ADC unit is connected with the coil of each electromagnet, and is connected on the tie point of each switch pair and power cathode, and CPU element is connected with power amplifier driver (13).

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