Patent US3812071A successfully refreshed from Google Patents.
US3650581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bearing systems
Assignee: KARL BODEN WILHELM GROTH AND DIE
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Filing: 1970-04-09
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Granted: 1972-03-21
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Expires: 1990-04-09
Abstract
Abstract A mechanical contact-free bearing system for a rotor, e.g., in a vacuum pump operating on the Holweck principle, rotatable at high speed comprises a magnetic system which includes at least one carrier magnet for suspending the rotor with its axis vertical. The bearing system includes at least one stabilizing device for counteracting and damping gyratory movements, e.g., procession and nutation, of the rotor. The stabilizing device includes sensors for producing signals responsively to deviation of the axis of the rotor from a predetermined position. An electronic control device amplifies the sensor signals and advances them in phase to produce output signals. Electromagnetic means utilize such output signals to apply electromagnetic forces to the rotor to apply correcting lateral forces to the rotor and further forces to anticipate the gyratory effect of such correcting forces and to damp oscillations of the rotor.
Inventors
- 👤 Karl Boden
- 👤 Dietrich Scheffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:44
CPC Classifications
F; F16; F16C; F16C32/00; F16C32/04; F16C32/0406; F16C32/044; F16C32/0444; F16C32/0451; F04; F04D; F04D19/00; F04D19/02; F04D19/04; F04D19/048; F16C32/047; F16C2300/00; F16C2300/30; F16C2300/34; F16C2300/40; F16C2300/62; F16C2360/00; F16C2360/44; F16C2360/45
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
269 words
In a magnetic bearing system for journaling a rotor in a stationary member for rotation about a substantially vertical axis without mechanical contact between the rotor and the stationary member, said rotor comprising ferromagnetic portions, a carrier magnet acting upon at least one of said ferromagnetic portions for supporting said rotor in axial direction, said carrier magnet producing a magnetic field with a vertical component for maintaining the rotor in a stable vertical position, said bearing system including a controlled stabilizing device disposed in a first horizontal plane on the stationary part, for maintaining the rotor in a specified radial position, said stabilizing device comprising at least two contactless sensors for measuring low and higher frequency deviations of the radial position of the rotor from a predetermined position and producing electrical sensor signals in accordance therewith, an electronic control device for amplifying and phase-displacing the sensor signals to produce output signals and electromagnetic means having at least three coils for producing substantially radially directed magnetic fields influencing at least one of said ferromagnetic portions on the rotor said magnetic fields being controlled in accordance with said output signals in such a way that said influence upon said ferromagnetic portions of the rotor produces a restoring force component restoring the rotor from its deviated position to said predetermined position and a damping force component for counteracting a lateral deflection brought about by the gyroscopic effect of the rotor and for damping such effect, said bearing system further including means disposed in a second horizontal plane for utilizing magnetic fields to achieve at least damping of vibratory movements of the rotor.
Claim 2
Dependent Claim
269 words
In a magnetic bearing system for journaling a rotor in a stationary member for rotation about a substantially vertical axis without mechanical contact between the rotor and the stationary member, said rotor comprising ferromagnetic portions, a carrier magnet acting upon at least one of said ferromagnetic portions for supporting said rotor in axial direction, said carrier magnet producing a magnetic field with a vertical component for maintaining the rotor in a stable vertical position, said bearing system including a controlled stabilizing device disposed in a first horizontal plane on the stationary part, for maintaining the rotor in a specified radial position, said stabilizing device comprising at least two contactless sensors for measuring low and higher frequency deviations of the radial position of the rotor from a predetermined position and producing electrical sensor signals in accordance therewith, an electronic control device for amplifying and phase-displacing the sensor signals to produce output signals and electromagnetic means having at least three coils for producing substantially radially directed magnetic fields influencing at least one of said ferromagnetic portions on the rotor said magnetic fields being controlled in accordance with said output signals in such a way that said influence upon said ferromagnetic portions of the rotor produces a restoring force component restoring the rotor from its deviated position to said predetermined position and a damping force component for counteracting a lateral deflection brought about by the gyroscopic effect of the rotor and for damping such effect, said bearing system further including means disposed in a second horizontal plane for utilizing magnetic fields to achieve at least damping of vibratory movements of the rotor.
Claim 3
Dependent Claim
64 words
A magnetic bearing system according to claim 1, in which said electronic control device contains an amplifier and a phase shifter, said phase shifter advancing said output signals in phase with respect to said sensor signals, said phase advancement being between zero and one quarter of the frequency period of the sensor signals, said phase advancement increasing with the frequency of the sensor signals.
Claim 4
Dependent Claim
59 words
A magnetic bearing system according to claim 1, in which said means disposed in said second horizontal plane comprises a stabilizing device having at least two contactless sensors, an electronic control device for amplifying and phase displacing the sensor signals to produce output signals and electromagnetic means for producing radially directed stabilizing magnetic fields responsively to said output signals.
Claim 5
Dependent Claim
84 words
A magnetic bearing system according to claim 1, wherein said carrier magnet acts upon said rotor at a point situated above the center of gravity of said rotor and wherein said means disposed in said second horizontal plane comprises a magnet disposed on said rotor in the region of the lower end thereof, said magnet producing a magnetic field which is symmetrical about the axis of said rotor, said stationary member having an electrically conductive part, said magnetic field cutting said electrically conductive part.
Claim 6
Dependent Claim
25 words
A magnetic bearing system according to claim 2, in which said phase shifter comprises a resistor and a capacitor connected in parallel with said resistor.
Claim 7
Dependent Claim
101 words
A magnetic bearing system according to claim 1, in which said stabilizing device cOmprises a plurality of sensors arranged in opposed pairs and an electronic control device for each pair of sensors, each control device including a high-frequency voltage source connected to the respective pair of sensors, a bridge circuit, said pair of sensors being disposed in one branch of said bridge circuit and a pair of rectifiers being disposed in the other branch thereof, means for tapping an error signal between the pair of sensors and between the pair of rectifiers and a push-pull amplifier for amplifying said error signal.
Claim 8
Dependent Claim
29 words
A magnetic bearing system according to claim 6, in which said other branch of said bridge includes an adjustable potentiometer for adjustment of said predetermined position of the rotor.
Claim 9
Dependent Claim
28 words
A magnetic bearing system according to claim 1, in which said constant magnetic field produced by said carrier magnet is circularly symmetrical about the axis of the rotor.
Claim 10
Dependent Claim
32 words
A magnetic bearing system according to claim 1, in which said carrier magnet comprises a circularly symmetrically magnetized permanent magnet, whose magnetic field contains components parallel to the axis of the rotor.
Claim 11
Dependent Claim
35 words
A magnetic bearing system according to claim 9, in which said carrier magnet comprises an annular magnet fitted to said stationary member and encircling a portion of the rotor which cooperates with said annular magnet.
Claim 12
Dependent Claim
19 words
A magnetic bearing system according to claim 9, in which said carrier magnet comprises a plurality of permanent magnets.
Claim 13
Dependent Claim
37 words
A magnetic bearing system according to claim 9, in which said rotor has a hollow portion and in which said carrier magnet comprises a bar magnet projecting into said hollow portion of said rotor and cooperates therewith.
Claim 14
Dependent Claim
28 words
A magnetic bearing system according to claim 1, in which said electromagnetic means comprises at least three electromagnets which are arranged around said ferromagnetic portion of said rotor.
Claim 15
Dependent Claim
51 words
A magnetic bearing system according to claim 13, in which said electromagnetic means comprises four electromagnets fitted to the stationary part and lying in a common horizontal plane and in which said stabilizing device includes four sensors, each disposed in the same vertical plane as a corresponding one of said electromagnets.
Claim 16
Dependent Claim
29 words
A magnetic bearing system according to claim 1, in which said electromagnetic means comprise a rotating field stator winding cooperating with one of said ferromagnetic portions of said rotor.
Claim 17
Dependent Claim
28 words
A magnetic bearing system according to claim 1, in which the electromagnetic means comprise electromagnets with poleshoes almost completely enclosing the entire respective ferromagnetic portion of said rotor.
Claim 18
Dependent Claim
35 words
A magnetic bearing system according to claim 1, in which said carrier magnet has a magnetic flux path, said flux path penetrating said electromagnetic means which thereby modifies the magnetic field of said carrier magnet.
Claim 19
Dependent Claim
35 words
A magnetic bearing system according to claim 1, having an assembly comprising a carrier magnet and a stabilizing device arranged in each of a plurality of horizontal planes, said assemblies being similar to one another.
Claim 20
Dependent Claim
37 words
A magnetic bearing system according to claim 1, which includes a plurality of stabilizing devices arranged on said stationary member and spaced apart longitudinally of said rotor, said rotor having respective ferromagnetic portions facing said stabilizing devices.
Claim 21
Dependent Claim
19 words
A magnetic bearing system according to claim 1, in which said rotor consists in its entirety of ferromagnetic material.
Claim 22
Dependent Claim
28 words
A magnetic bearing system according to claim 1, in which said rotor has a ring of ferromagnetic material at least in the horizontal plane of said carrier magnet.
Claim 23
Dependent Claim
25 words
A magnetic bearing system according to claim 1, in which said carrier magnet and said stabilizing device are disposed at one end of said rotor.
Claim 24
Dependent Claim
22 words
A magnetic bearing system according to claim 22, in which said end of the rotor comprises a hollow cylinder of ferromagnEtic material.
Claim 25
Dependent Claim
47 words
A magnetic bearing system according to claim 1, in which said ferromagnetic portion of said rotor cooperating with said electromagnetic means of said stabilizing device comprises stacked annular laminations insulated from one another and connecting means holding said laminations together to provide low eddy-current and hysteresis loss.
Claim 26
Dependent Claim
37 words
A magnetic bearing system according to claim 1, in which said ferromagnetic portion of said rotor cooperating with said electromagnetic means of said stabilizing device comprises soft-magnetic, moulded ceramic material and a sheath for said ceramic material.
Claim 27
Dependent Claim
32 words
A magnetic bearing system according to claim 1, in which said rotor has a hollow end and in which said electromagnetic means of said stabilizing device extend into said hollow rotor end.
Claim 28
Dependent Claim
31 words
A magnetic bearing system according to claim 1, in which said rotor has a hollow end and in which said sensors of said stabilizing device extend into said hollow rotor end.
Claim 29
Dependent Claim
27 words
A magnetic bearing system according to claim 26, further comprising a gastight sleeve of nonmagnetic, electrically conductive material disposed between the electromagnetic means and said rotor end.
Claim 30
Dependent Claim
34 words
A magnetic bearing system according to claim 1, in which said stationary member comprises a housing surrounding said rotor and in which said carrier magnet and said stabilizing device are disposed outside said housing.
Claim 31
Dependent Claim
39 words
A magnetic bearing system according to claim 1, in which said sensors comprise inductive pickups whose inductance is variable in accordance with their distance from a respective portion of said rotor, said respective portion comprising nonmagnetic electrically conductive material.
Claim 32
Dependent Claim
59 words
A magnetic bearing system according to claim 1, in which said carrier magnet is disposed adjacent said sensors and in which said sensors comprise inductive pickups disposed within the influence of the magnetic field of said carrier magnet, the inductance of said inductive pickups being variable by variation of the influence of the magnetic field of the carrier magnet.
Claim 33
Dependent Claim
16 words
A magnetic bearing system according to claim 1, in which said sensors comprise capacitive proximity detectors.
Claim 34
Dependent Claim
37 words
A magnetic bearing system according to claim 1, in which said sensors comprise photoelectric distance detectors each of which includes a light source and a photocell, said rotor being disposed between said light source and said photocell.
Claim 35
Dependent Claim
51 words
A magnetic bearing system according to claim 1, in which said sensors comprise galvanomagnetic semiconductor elements whose electrical characteristics can be influenced by magnetic fields and in which said sensors are arranged in a region where the magnetic field strength alters as a function of the horizontal position of the rotor.
Claim 36
Dependent Claim
22 words
A magnetic bearing system according to claim 1, further comprising nonmetallic gas tight material, said sensors being encased in said gastight material.
Claim 37
Dependent Claim
26 words
A magnetic bearing system according to claim 1, further comprising means for producing a rotating electric field acting upon said electromagnetic means for rotating said rotor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |