Patent EP0381898A2 successfully refreshed from Google Patents.
EP0381898A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for cancelling vibrations of rotating machines with active magnetic bearings
Assignee: PROTO-TECHNOLOGY Corp
•
Filing: 1989-12-21
•
Granted: —
•
Expires: 2009-12-21
Abstract
Abstract A method and apparatus for reducing the vibrations of a rotating machine equipped with an active magnetic suspension including at least two vibration detectors (7) located on the machine frame for detecting disturbance applied to the frame, and at least an additional selective feedback circuit (18) which generates cancelling vibrations by transforming the sensed residual vibrations into a plurality of components which together define the vibrations at a plurality of different locations in the frequency domain, separately modifying the independent components and transforming the modified components into a drive signalt to the magnet suspension control (13, Ex, Ey).
Inventors
- 👤 Tom A. Hendrickson
- 👤 John S. Leonard
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 01:36
CPC Classifications
F; F16; F16C; F16C32/00; F16C32/04; F16C32/0406; F16C32/044; F16C32/0444; F16C32/0451; F16C32/0453
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
In a machine having a rotatable shaft, a vibration cancellation apparatus comprising: (a) primary active magnetic support bearings supporting the rotatable shaft both radially and axially in the machine; (b) an electronic control continuously controlling the positional alignment of the rotatable shaft and the stiffness and damping characteristics of said primary support bearings, thereby allowing the rotatable shaft to rotate about its inertial axis and substantially eliminating rotating shaft unbalance forces; (c) means for sensing the vibrations of a stator or frame of the machine; and (d) an adaptive signal processor for transforming said sensed vibrations and generating signals in response thereto to adjust said primary support bearings causing the rotatable shaft to move, thereby creating inertia forces to cancel said sensed vibrations.
Claim 2
Dependent Claim
123 words
In a machine having a rotatable shaft, a vibration cancellation apparatus comprising: (a) primary active magnetic support bearings supporting the rotatable shaft both radially and axially in the machine; (b) an electronic control continuously controlling the positional alignment of the rotatable shaft and the stiffness and damping characteristics of said primary support bearings, thereby allowing the rotatable shaft to rotate about its inertial axis and substantially eliminating rotating shaft unbalance forces; (c) means for sensing the vibrations of a stator or frame of the machine; and (d) an adaptive signal processor for transforming said sensed vibrations and generating signals in response thereto to adjust said primary support bearings causing the rotatable shaft to move, thereby creating inertia forces to cancel said sensed vibrations.
Claim 3
Dependent Claim
47 words
A vibration cancellation apparatus according to claim 1, further comprising secondary auxiliary bearings adapted to contact and support said rotatable shaft on failure of said primary support bearings, said second bearings positioned to prevent the rotatable shaft from contacting said primary support bearings on said failure condition.
Claim 4
Dependent Claim
52 words
A vibration cancellation apparatus according to claim 2, wherein said second auxiliary bearings comprise rolling element bearings, the innermost diameter of which are greater than the diameter of said rotatable shaft by an amount which is less than the distance between the surface of said rotatable shaft and said primary support bearings.
Claim 5
Dependent Claim
51 words
A vibration cancellation apparatus according to claim 2, wherein said secondary auxiliary bearings comprise journal bearings, the innermost diameter of which are greater than the diameter of said rotatable shaft by an amount which is less than the distance between the surface of said rotatable shaft and said primary support bearings.
Claim 6
Dependent Claim
54 words
A vibration cancellation apparatus according to any preceding claim wherein the adaptive signal processor comprises an electronic processing circuit connecting said stator or frame vibration sensors, including synchronising means, a first transformer receiving time waveform samples, and a second transformer producing modified time waveform samples which are fed to the active magnetic control circuits.
Claim 7
Dependent Claim
17 words
A vibration cancellation device according to claim 5, wherein the first and second transformer are Fourier transformers.
Claim 8
Dependent Claim
35 words
A vibration cancellation apparatus according to any preceding claim wherein said electronic control includes means for controlling the stiffness of said active magnetic bearings at the rotational speed of the rotatable shaft and multiples thereof.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.