Background technique
Molecular pump is a kind of vacuum pump, and it is to utilize the impeller of rotor of high speed rotating to give gas molecule Momentum Transfer, makes it to obtain directed velocity, thereby gas is compressed and is driven to relief opening, is taken away by fore pump.The magnetic suspension molecular pump is the molecular pump of a kind of employing magnetic bearing (claiming Active Magnetic Suspending Bearing again) as the supporting of molecular pump rotor, it utilize magnetic bearing with rotor stability be suspended in aerial, make rotor in the high speed operation process and between the stator, not have Mechanical Contact, have and do not have the machinery wearing and tearing, energy consumption is low, allow the rotating speed height, noise is low, the life-span is long, need not advantage such as lubricant medium, present magnetic suspension molecular pump is widely used in the fields such as acquisition of condition of high vacuum degree, high-cleanness, high vacuum environment.
The internal structure of magnetic suspension molecular pump as shown in Figure 1, the rotor of described magnetic suspension molecular pump comprises rotor shaft 7 and the impeller 1 of fixedlying connected with described rotor shaft 7, if described magnetic suspension molecular pump vertically is provided with, then described impeller 1 is fixedly mounted on the top of described rotor shaft 7; The middle part of described rotor shaft 7 compartment of terrain according to this is arranged with devices such as first radial direction magnetic bearing 6, motor 8 and second radial direction magnetic bearing 9, and said apparatus has constituted the rotor axial system of described magnetic suspension molecular pump jointly.
The magnetic suspension molecular pump of prior art, under the normality, rotor centroid 2 is arranged on the axis of described rotor shaft 7 and between described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9, as shown in Figure 2.In the course of the work, described rotor can be subjected to coming from molecular pump self or extraneous disturbing force, causes that described rotor produces the rotation around described rotor centroid 2 of translation (being horizontal motion), axial motion and described rotor.Wherein, described axial motion can be regulated by the parameter that changes first axial magnetic bearing 13 and/or second axial magnetic bearing 15, the translation of described rotor or described rotor then need to regulate by the Control Parameter of adjusting described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 simultaneously around the rotation of described rotor centroid 2, also are that the translation and the described rotor of described rotor controlled by described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 jointly around the rotation of described rotor centroid 2.
If the disturbed dynamic effect of described rotor has produced the rotation around described rotor centroid 2 of the translation of described rotor and described rotor simultaneously, these two kinds of motions will intercouple, and make the motion conditions of described rotor become very complicated.In the influence of elimination disturbing force, when described rotor is returned to normal, the Control Parameter that need change described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 is simultaneously adjusted above-mentioned rotor translation and rotor rotation, make control procedure very complicated, the control difficulty is big, is unfavorable for the stable operation of magnetic suspension molecular pump system.
Summary of the invention
Technical problem to be solved by this invention is that the barycenter owing to rotor is arranged between first radial direction magnetic bearing and second radial direction magnetic bearing in the prior art, rotor motion situation complexity when disturbed dynamic effect rotor produces translation and rotation simultaneously, the difficulty of adjusting the magnetic bearing parameter is bigger, the control procedure complexity, the required adjustment time is long, inefficient technical problem, when rotor translation takes place simultaneously and rotates, can make the translation of rotor and rotate two kinds of basic decoupling zeros mutually of motion and provide a kind of, simplify magnetic suspension molecular pump control procedure greatly, reduce the control difficulty, improve the magnetic suspension molecular pump and the manufacture method thereof of magnetic suspension molecular pump system's control efficiency and stability.
For solving the problems of the technologies described above, the technical solution used in the present invention is as follows:
A kind of magnetic suspension molecular pump comprises the pump housing and the rotor axial system that is arranged on described pump housing inner chamber; Described rotor axial system comprises rotor, first radial direction magnetic bearing, second radial direction magnetic bearing, first axial magnetic bearing and second axial magnetic bearing, and described rotor comprises rotor shaft and the impeller of fixing with described rotor shaft; The middle part of described rotor shaft compartment of terrain according to this is arranged with described first radial direction magnetic bearing and described second radial direction magnetic bearing, the bottom of described rotor shaft is arranged with described first axial magnetic bearing and described second axial magnetic bearing, and described rotor shaft is by described first radial direction magnetic bearing, described second radial direction magnetic bearing, described first axial magnetic bearing and the supporting of described second axial magnetic bearing; Under the normality, rotor centroid is arranged on the axis of described rotor shaft and with the barycenter of described first radial direction magnetic bearing and overlaps.
A kind of manufacture method of above-mentioned magnetic suspension molecular pump, comprise by changing structure, the mass distribution of rotor shaft, perhaps change structure, the mass distribution of impeller, overlap so that the rotor centroid of rotor is arranged on the axis of described rotor shaft and with the barycenter of first radial direction magnetic bearing.
Technique scheme of the present invention has the following advantages compared to existing technology:
1. magnetic suspension molecular pump provided by the invention, normality lower rotor part barycenter is arranged on the axis of rotor shaft and with the barycenter of first radial direction magnetic bearing and overlaps, when translation takes place and rotates in rotor simultaneously, can make the translation of rotor and rotate two kinds of basic decoupling zeros mutually of motion, the rotor translation is mainly adjusted control by first radial direction magnetic bearing, rotor rotation is adjusted control by second radial direction magnetic bearing, thereby simplified control procedure greatly, reduced the control difficulty, improved molecular pump system control efficiency and stability;
The manufacture method of magnetic suspension molecular pump 2. provided by the invention, by changing structure, the mass distribution of rotor shaft, perhaps change structure, the mass distribution of impeller, so that being arranged on the axis of rotor shaft and with the barycenter of first radial direction magnetic bearing, rotor centroid overlaps, said method is all fairly simple, is easy to realize.
3. magnetic suspension molecular pump provided by the invention, when the magnetic suspension molecular pump tilts to install, when static suspension, the Control Parameter that only needs to revise first radial direction magnetic bearing, first axial magnetic bearing and second axial magnetic bearing can realize the rotor axial stable suspersion again, and is easy and simple to handle.
Embodiment
As shown in Figure 1, it is the structural representation of magnetic suspension molecular pump involved in the present invention, the molecular pump of magnetic suspension described in the present embodiment vertically is provided with, described magnetic suspension molecular pump comprises the pump housing 3, be arranged on other structures that the magnetic suspension molecular pump should have described in the rotor axial system of the described pump housing 3 inner chambers and the prior art, because the present invention does not relate to above-mentioned other structures, this does not give unnecessary details.
Described rotor axial system comprises rotor, first radial direction magnetic bearing 6, second radial direction magnetic bearing 9, first axial magnetic bearing 13 and second axial magnetic bearing 15.Described rotor comprise rotor shaft 7, with fixing impeller 1 of described rotor shaft 7 and the build-up member that is used for fixing described impeller 1, as screw, nut etc.
The axis of described rotor shaft 7 vertically is provided with, and described impeller 1 is fixedly installed on the top of described rotor shaft 7.The bottom of described rotor shaft 7 is provided with described first axial magnetic bearing 13, described second axial magnetic bearing 15, thrust disc 14 and axially protects bearing 12 and be used to detect the axial sensor 16 of described rotor axial displacement signal.The middle part of described rotor shaft 7 compartment of terrain according to this is arranged with first and radially protects bearing 4, first radial transducer 5, first radial direction magnetic bearing 6, motor 8, second radial direction magnetic bearing 9, second radial transducer 10 and second radially to protect devices such as bearing 11.Described first radial direction magnetic bearing 6 comprises the first radial direction magnetic bearing stator and the first radial direction magnetic bearing rotor, and the described first radial direction magnetic bearing stator is fixedlyed connected with the described pump housing 3, and the described first radial direction magnetic bearing rotor is fixedlyed connected with described rotor shaft 7.Described first radial transducer 5 is used to detect the displacement signal of stating rotor in described first radial transducer 5 places, comprises rotor translation displacement signal and rotor rotation displacement signal.Described second radial direction magnetic bearing 9 comprises the second radial direction magnetic bearing stator and the second radial direction magnetic bearing rotor, and the described second radial direction magnetic bearing stator is fixedlyed connected with the described pump housing 3, and the described second radial direction magnetic bearing rotor is fixedlyed connected with described rotor shaft 7.Described second radial transducer 10 is used to detect the displacement signal of stating rotor in described second radial transducer 10 places, comprises rotor translation displacement signal and rotor rotation displacement signal.Described rotor shaft 7 is by described first radial direction magnetic bearing 6, described second radial direction magnetic bearing 9, described first axial magnetic bearing 13 and 15 supportings of described second axial magnetic bearing.Under the normality when rotor static suspension (described), rotor centroid 2 is arranged on the axis of described rotor shaft 7 and with the barycenter of described first radial direction magnetic bearing 6 and overlaps, as shown in Figure 3.Described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 can apply radial electromagnetic force to described rotor, and described rotor is returned to normal.
The control system of described magnetic suspension molecular pump comprises displacement detector 18, speed detector 19 and magnetic suspension molecular pump controller 20; Described displacement detector 18 is used to receive displacement signal, its signal input part is connected with the signal output part of described first radial transducer 5, described second radial transducer 10 and described axial sensor 16, and the signal output part of described displacement detector 18 is connected with the signal input part of described magnetic suspension molecular pump controller 20; Described speed detector 19 is used to detect the tach signal of described rotor, its signal input part is connected to the rotating speed detecting sensor by the tenminal block 17 of described magnetic suspension molecular pump, and the signal output part of described speed detector 19 is connected with the signal input part of described magnetic suspension molecular pump controller 20.
The displacement signal that described magnetic suspension molecular pump controller 20 obtains according to described displacement detector 18, call suitable control algorithm and analyze computing, finally drive corresponding magnetic bearing (in described first radial direction magnetic bearing 6, described second radial direction magnetic bearing 9, described first axial magnetic bearing 13 and described second axial magnetic bearing 15 one or more) output electromagnetic force the motion of described rotor is applied control.Described magnetic suspension molecular pump controller 20 is monitored in real time the rotation of described rotor, and is adjusted the rotating speed of described rotor as required according to the tach signal that described speed detector 19 obtains.
The said structure of described magnetic suspension molecular pump is in conjunction with its controlling method, when translation takes place and rotates in described rotor simultaneously, can make the basic decoupling zero mutually of two kinds of motions of rotation of described rotor translation and described rotor, simplify control procedure greatly, reduced the control difficulty, improved the molecular pump system effectiveness around described rotor centroid 2.Described magnetic suspension molecular pump is vertically installed setting, described rotor shaft 7 axis that are the magnetic suspension molecular pump are vertically the time, its controlling method comprises: when 1. described magnetic suspension molecular pump is vertically installed, the gravity of described rotor is born jointly by described first axial magnetic bearing 13 and described second axial magnetic bearing 15, when adjusting described rotor static suspension, only need the Control Parameter of described first axial magnetic bearing 13 and described second axial magnetic bearing 15 made amendment and to realize described rotor stable suspersion in the axial direction.
2. in the described magnetic suspension molecular pump running, if the disturbed dynamic effect of described rotor, described rotor produces translation.Described first radial transducer 5 and described second radial transducer 10 all can detect the translation signal of described rotor, and described first radial transducer 5 and described second radial transducer 10 send to described magnetic suspension molecular pump controller 20 with detected rotor translation signal by described displacement detector 18.Described magnetic suspension molecular pump controller 20 sends position, the inhibition described rotor translation of control command to adjust described rotor to described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 respectively through operational analysis.Because described rotor centroid 2 overlaps with the barycenter of described first radial direction magnetic bearing 6, the electromagnetic force of described second radial direction magnetic bearing 9 output to the inhibition effect of described rotor translation very I to ignore, so the translation of described rotor mainly by 6 controls of described first radial direction magnetic bearing, can make described rotor return to normal.
3. in the described magnetic suspension molecular pump running, if the disturbed dynamic effect of described rotor, described rotor rotates, and promptly described rotor rotates around described rotor centroid 2, and described first radial transducer 5 and described second radial transducer 10 all will detect the turn signal of described rotor.Described first radial transducer 5 and described second radial transducer 10 send to described magnetic suspension molecular pump controller 20 with detected rotor rotation signal by described displacement detector 18, described magnetic suspension molecular pump controller 20 through operational analyses respectively to described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 send control command with the position of adjusting described rotor, suppress described rotor rotation.Because described rotor centroid 2 overlaps with the barycenter of described first radial direction magnetic bearing 6, the electromagnetic force of described first radial direction magnetic bearing 6 output can only be adjusted described rotor translation and not have inhibitory action for the rotation of described rotor, so the rotation of described rotor can make described rotor return to normal by 9 controls of described second radial direction magnetic bearing.4. in the described magnetic suspension molecular pump running, if the disturbed dynamic effect of described rotor, described rotor has produced translation simultaneously and has centered on the rotation of described rotor centroid 2, and so described first radial transducer 5 and described second radial transducer 10 all will detect the translation signal and the turn signal of described rotor.Described first radial transducer 5 and described second radial transducer 10 respectively will be separately detected rotor translation signal and rotor rotation signal all send to described magnetic suspension molecular pump controller 20 by described displacement detector 18, described magnetic suspension molecular pump controller 20 responds to translation signal and turn signal respectively through operational analyses.At rotor translation signal, described magnetic suspension molecular pump controller 20 will send control command to adjust the position of described rotor to described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 respectively through operational analysis, suppress described rotor translation, but because described rotor centroid 2 overlaps with the barycenter of described first radial direction magnetic bearing 6, the electromagnetic force of described second radial direction magnetic bearing 9 output to the inhibition effect of described rotor translation very I to ignore, so this moment, the translation of described rotor was mainly controlled by described first radial direction magnetic bearing 6, and described rotor is returned to normal; At the rotor rotation signal, described magnetic suspension molecular pump controller 20 will send control command to adjust the position of described rotor to described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 respectively through operational analysis, suppress described rotor rotation, but because described rotor centroid 2 overlaps with the barycenter of described first radial direction magnetic bearing 6, the electromagnetic force of described first radial direction magnetic bearing 6 output can only be adjusted described rotor translation and not have inhibitory action for the rotation of described rotor, so this moment, the rotation of described rotor was controlled by described second radial direction magnetic bearing 9, and described rotor is returned to normal.
5. in the described magnetic suspension molecular pump running, if the disturbed dynamic effect of described rotor, described rotor produces axial motion, described axial sensor 16 will detect the axial displacement signal of described rotor, described axial sensor 16 sends to described magnetic suspension molecular pump controller 20 with detected axial displacement signal by described displacement detector 18, described magnetic suspension molecular pump controller 20 will send control command to adjust the position of described rotor to described first axial magnetic bearing 13 and/or described second axial magnetic bearing 15 through operational analysis, suppress the axial motion of described rotor, described rotor is returned to normal.
Certainly, above-mentioned controlling method also comprises necessary other conventional methods of the described magnetic suspension molecular pump of control in the prior art, because the present invention does not relate to above-mentioned other conventional methods, this does not give unnecessary details.
The manufacture method of described magnetic suspension molecular pump provided by the invention, comprise structure, mass distribution by changing described rotor shaft 7, perhaps change structure, the mass distribution of described impeller 1, overlap so that the described rotor centroid 2 of described rotor is arranged on the axis of described rotor shaft 7 and with the barycenter of described first radial direction magnetic bearing 6.In the present embodiment, by changing the mass distribution of described rotor shaft 7, make and carry and overlap on described rotor centroid 2 positions with the barycenter of described first radial direction magnetic bearing 6.
Certainly, above-mentioned manufacture method also comprises the conventional method step that is used to make a complete magnetic suspension molecular pump in the prior art, because the present invention does not relate to above-mentioned conventional method step, this does not give unnecessary details.
In other embodiments, use needs according to different user, described magnetic suspension molecular pump also tiltable install to be placed, and the angle of promptly described rotor shaft 7 axis and vertical direction is greater than 0 degree and smaller or equal to 90 degree, is 45 to spend at the angle of described rotor shaft 7 axis of present embodiment and vertical direction.The controlling method of described magnetic suspension molecular pump, comprise: 1. because described rotor centroid 2 is arranged on the axis of described rotor shaft 7 and with the barycenter of described first radial direction magnetic bearing 6 overlaps, when described magnetic suspension molecular pump tilted to install, the gravity of described rotor was born jointly by described first radial direction magnetic bearing 6, described first axial magnetic bearing 13 and described second axial magnetic bearing 15.When adjusting described rotor static suspension, only need the Control Parameter of described first radial direction magnetic bearing 6, described first axial magnetic bearing 13 and described second axial magnetic bearing 15 made amendment and to realize described rotor stable suspersion in the axial direction, and needn't adjust the parameter of described second radial direction magnetic bearing 9.
2. in the described magnetic suspension molecular pump running, if the disturbed dynamic effect of described rotor, described rotor produces translation, be that described rotor produces translation, described first radial transducer 5 and described second radial transducer 10 all will detect the translation signal of described rotor, described first radial transducer 5 and described second radial transducer 10 send to described magnetic suspension molecular pump controller 20 with detected rotor translation signal by described displacement detector 18, described magnetic suspension molecular pump controller 20 sends control command to adjust the position of described rotor to described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 respectively through operational analysis, suppress described rotor translation, but because described rotor centroid 2 overlaps with the barycenter of described first radial direction magnetic bearing 6, the electromagnetic force of described second radial direction magnetic bearing 9 output to the inhibition effect of described rotor translation very I to ignore, so this moment, the translation of described rotor was mainly controlled by described first radial direction magnetic bearing 6, and described rotor is returned to normal.
3. in the described magnetic suspension molecular pump running, if the disturbed dynamic effect of described rotor, described rotor rotates, be that described rotor rotates around described rotor centroid 2, described first radial transducer 5 and described second radial transducer 10 all will detect the turn signal of described rotor, described first radial transducer 5 and described second radial transducer 10 send to described magnetic suspension molecular pump controller 20 with detected rotor rotation signal by described displacement detector 18, described magnetic suspension molecular pump controller 20 sends control command to adjust the position of described rotor to described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 respectively through operational analysis, suppress described rotor rotation, but because described rotor centroid 2 overlaps with the barycenter of described first radial direction magnetic bearing 6, the electromagnetic force of described first radial direction magnetic bearing 6 output can only be adjusted described rotor translation and not have inhibitory action for the rotation of described rotor, so this moment, the rotation of described rotor was controlled by described second radial direction magnetic bearing 9, and described rotor is returned to normal.4. in the described magnetic suspension molecular pump running, if the disturbed dynamic effect of described rotor, described rotor has produced translation simultaneously and has centered on the rotation of described rotor centroid 2, so described first radial transducer 5 and described second radial transducer 10 all will detect the translation signal and the turn signal of described rotor, described first radial transducer 5 and described second radial transducer 10 respectively will be separately detected rotor translation signal and rotor rotation signal all send to described magnetic suspension molecular pump controller 20 by described displacement detector 18, described magnetic suspension molecular pump controller 20 responds to translation signal and turn signal respectively through operational analyses; At rotor translation signal, described magnetic suspension molecular pump controller 20 sends control command to adjust the position of described rotor to described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 respectively through operational analysis, suppress described rotor translation, but because described rotor centroid 2 overlaps with the barycenter of described first radial direction magnetic bearing 6, the electromagnetic force of described second radial direction magnetic bearing 9 output to the inhibition effect of described rotor translation very I to ignore, so this moment, the translation of described rotor was mainly controlled by described first radial direction magnetic bearing 6, and described rotor is returned to normal; At the rotor rotation signal, described magnetic suspension molecular pump controller 20 sends control command to adjust the position of described rotor to described first radial direction magnetic bearing 6 and described second radial direction magnetic bearing 9 respectively through operational analysis, suppress described rotor rotation, but because described rotor centroid 2 overlaps with the barycenter of described first radial direction magnetic bearing 6, the electromagnetic force of described first radial direction magnetic bearing 6 output can only be adjusted described rotor translation and not have inhibitory action for the rotation of described rotor, so this moment, the rotation of described rotor was controlled by described second radial direction magnetic bearing 9, and described rotor is returned to normal.5. in the described magnetic suspension molecular pump running, if the disturbed dynamic effect of described rotor, described rotor produces axial motion, and described axial sensor 16 detects the axial displacement signal of described rotor.Described axial sensor 16 sends to described magnetic suspension molecular pump controller 20 with detected axial displacement signal by described displacement detector 18, described magnetic suspension molecular pump controller 20 sends control command with the position of adjusting described rotor, the axial motion that suppresses described rotor through operational analysis to described first axial magnetic bearing 13 and/or described second axial magnetic bearing 15, and described rotor is returned to normal.
Obviously, the foregoing description only is for example clearly is described, and is not the qualification to mode of execution.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here need not also can't give exhaustive to all mode of executions.And conspicuous variation of being extended out thus or change still are among the protection domain of the invention.