Method and transducer and apparatus for selectively measuring oscillation components from an oscillation spectrum

• US 4,004,464 A
• Filed: 08/12/1975
• Issued: 01/25/1977
• Est. Priority Date: 08/14/1974
• Status: Expired due to Term

• Current Assignee: GEBR. Hofmann GmbH & Co. KG Maschinenfabrik
• Original Assignee: GEBR. Hofmann GmbH & Co. KG Maschinenfabrik
• Inventors: Himmler, Gunther
• Primary Examiner(s): Gill, James J.
• Application Number:
  US05/603,970
• Time in Patent Office: 532 Days
• Field of Search: 73/462, 73/464, 73/71.4, 73/71.2
• US Class Current: 73/462
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01H 11/02 by magnetic means, e.g. reluctance
• CPC Class Codes: G01M 1/22 and converting vibrations due to imbalance into electric variables

Abstract

A method and apparatus for selectively measuring oscillation components and vectors in a spectrum, particularly produced by detecting unbalance of a rotary body, with a transducer which includes a pair of coils which move in an alternating magnetic field having an adjustable frequency and an integrating circuit connected to the transducer output so that the desired components are selected in the transducer and integrating circuit.

Claims

1. A method of selectively measuring oscillation components and oscillation vectors of a rotor in an oscillation spectrum with a transducer, comprising the steps of applying the oscillation movement to an induction device forming part of the transducer, providing a magnetic alternating field having an adjustable frequency which is kept constant at an integral multiple of the rotor frequency, producing from the operating movement of the induction device in the magnetic field an electrical alternating current voltage and integrating said voltage to produce a signal which is proportional to the amplitude of the oscillation component which is selected by the set adjustment of said constant frequency.

2. A method according to claim 1, further including producing a sine-related and a cosine-related reference voltage by detecting the output of the transducer produced by said rotor and combining said sine-related and cosine-related voltages with the integrated voltages to produce electrical alternating-current voltages at unbalance measuring frequency and to determine two unbalance vector components.

3. A method according to claim 2 including producing and vectorially adding two said electrical alternating-current voltages at unbalance-measuring frequency, which respectively represent said two unbalance vector components, and determining the phase position of the unbalance by phase comparison of the signal produced from the vectorial addition operation, with one of said reference voltages.

4. Apparatus for selectively measuring oscillation components and oscillation vectors of a rotor in an oscillation movement spectrum comprising:

a transducer for sensing the oscillation movements of said rotor, said transducer including means for producing an alternating magnetic field and at least one moving coil operatively connected to the alternating magnetic field, the frequency of the alternating magnetic field being adjustable to a constant value at an integral multiple of the rotor frequency;

and integrating means connected to the output of the transducer for providing an integrated signal.

5. Apparatus according to claim 4, wherein the transducer includes means for producing a sine-related voltage and a cosine-related reference voltage from said rotor.

6. Apparatus according to claim 5 wherein said integrating means produces a plurality of current voltage outputs further including multiplying means connected to the output of said integrating means for multiplying the direct-current voltages delivered at the respective outputs of the integrating means by said sine and cosine alternating-current reference voltages corresponding to the rotary body frequencies.

7. Apparatus according to claim 6 further including summing means connected to the output of the multiplying means for geometrically summing the alternating-current voltages delivered by the multiplying means;

and phase comparison means connected to the output of said summing means, for determining the phase position of the unbalance of the rotary body from the phase relation between said reference voltages and the summed voltages.

8. Apparatus according to claim 4 including two induction coils for forming two alternating magnetic fields which lie in mirror image to each other, and two moving coils which are movable in equal phase in the alternating magnetic fields.

9. Apparatus according to claim 8 wherein said moving coils are arranged on a common sensing rod and are arranged symmetrically with respect to a central plane that is perpendicular to the longitudinal dimension of the sensing rod.