Combination balance analyzer and vibration spectrum analyzer

• US 3,938,394 A
• Filed: 11/30/1973
• Issued: 02/17/1976
• Est. Priority Date: 11/30/1973
• Status: Expired due to Term

• Current Assignee: IRD Mechanalysis, Inc.
• Original Assignee: IRD Mechanalysis, Inc.
• Inventors: Morrow, Robert S., Penn, Lloyd D.
• Primary Examiner(s): Gill, James J.
• Application Number:
  US05/420,594
• Time in Patent Office: 809 Days
• Field of Search: 73/462, 73/71.4, 324/79 R
• US Class Current: 73/462
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01M 1/08 Instruments for indicating directly the magnitude and phase of the imbalance
• CPC Class Codes: G01M 1/22 and converting vibrations due to imbalance into electric variables
• CPC Class Codes: H03B 1/04 Reducing undesired oscillations, e.g. harmonics
• CPC Class Codes: H03B 2200/0092 Measures to linearise or reduce distortion of oscillator characteristics
• CPC Class Codes: H03B 23/00 Generation of oscillations periodically swept over a predetermined frequency range angle-modulating circuits in general H03C3/00
• CPC Class Codes: H03B 28/00 Generation of oscillations by methods not covered by groups H03B5/00 - H03B27/00, including modification of the waveform to produce sinusoidal oscillations analogue function generators for performing computing operations G06G7/26; use of transformers for conversion of waveform in ac-ac converters H02M5/18
• CPC Class Codes: H03H 11/126 using a single operational amplifier H03H11/1204 takes precedence; parallel-T filters H03H11/1295
• CPC Class Codes: H03H 11/42 Gyrators used in frequency selective networks H03H11/08
• CPC Class Codes: H03K 3/013 Modifications of generator to prevent operation by noise or interference
• CPC Class Codes: H03K 4/02 having stepped portions, e.g. staircase waveform
• CPC Class Codes: H03K 4/06 having triangular shape
• CPC Class Codes: H03K 4/502 the capacitor being charged from a constant-current source
• CPC Class Codes: H03K 5/08 by limiting; by thresholding; by slicing, i.e. combined limiting and thresholding H03K5/07 takes precedence; comparing one pulse with another H03K5/22; providing a determined threshold for switching H03K17/30
• CPC Class Codes: H03K 5/1252 Suppression or limitation of noise or interference specially adapted for transmission systems H04B15/00, H04L25/08
• CPC Class Codes: H03K 7/06 Frequency or rate modulation, i.e. PFM or PRM

Abstract

A combination electronic device provides balance analyzing capabilities, narrow band and wide band spectrum analysis capabilities, automatic tracking filtering capabilities, precision dynamic balancing with remote phase presentation, and tracking filtering. The device presents multiple functions including:

1. A testing function;

2. A balancing function;

3. A tracking filter function;

4. A filter-out-speed function;

5. A filter-out-frequency function;

6. Spectrum analysis function.

Included within the circuitry are the following components:

A. a vibration signal conditioning circuit;

B. an active filter having the equivalent of a four-pole response with a two-pole delay;

C. a pulse-to-sine and pulse-to-consine reference signal generating circuit;

D. a reference pulse conditioning circuit;

E. a digital sweep circuit for spectrum analysis;

F. switching circuitry to accommodate all six functions;

G. adjustment means to accommodate full-scale presentation of data on X-Y recorders.

The system also is adapted to accommodate multiple input sources, for example, electrical displacement signals, electrical velocity signals, electrical accelerometer signals, electrical acoustic signals.

Claims

1. In an electro-mechanical apparatus for detecting instantaneous amplitude of harmonic vibrations of a rotating body including:

an electromagnetic transducer for converting instantaneously some function of harmonic displacement into a complex electrical signal having a fundamental frequency corresponding to the instantaneous rotational velocity of said rotating body, the improvement comprising;

independent means for generating a reference signal having uniformly increasing frequency said means being distinct from the said rotating body and also being distinct from said electromechanical transducer;

signal filter means connected to receive the said complex electrical signal;

signal filter means being responsive to said reference signal for instantaneously producing a resultant signal substantially free of components of the said complex electrical signal other than those at the existing instantaneous frequency of the said reference signal.

2. Apparatus according to claim 1 including means for adjusting the minimum frequency and the maximum frequency of the range of the said reference signal.

3. In an electro-mechanical apparatus of claim 1 the improvement comprising:

switch means within said apparatus including two input terminals and one output terminal,

integrating circuitry having an input contact and an output contact, said switch means being adapted to connect;

a. a first of said input terminals to the said input contact and to connect the said output contact to the said output terminal;

b. a first of said input terminals to the said output terminal;

c. a second of the said input terminals to the said output terminal;

d. a second of the said input terminals to the said input contact and to connect the said output contact to the said output terminal;

and means for connecting said transducer to said first of said input terminals when the said complex electrical signal is velocity responsive and means for connecting the said transducer to the said second of said input terminals when the said complex electrical signal is acceleration responsive and means for connecting said transducer to the said first of said input terminals when the said complex electrical signal is displacement responsive.

4. In an electro-mechanical apparatus of claim 1, the improvement in said signal filter means comprising an active filter having the equivalent of a four-pole filter response with the equivalent of a two-pole filter delay.

5. In an electro-mechanical apparatus for detecting amplitude and phase relationships of harmonic vibrations of a rotating body, including:

an electromagnetic transducer for converting instantaneously some function of harmonic displacement into a complex electrical signal having a fundamental frequency corresponding to the instantaneous rotational velocity of the said rotating body, including means for filtering the said complex electrical signal to suppress signal components at frequencies other than a selected frequency and to pass without significant distortion the signal components of the said selected frequency;

a first signal channel and second signal channel, the two said channels being identical and each including in series a first multiplier, a low pass filter and a second multiplier;

means for generating a sine wave signal at a first reference frequency and means for generating a cosine wave signal at the same first reference frequency;

means for delivering the said complex electrical signal to the first multiplier of the said first channel and to the said first multiplier of the said second channel;

means for delivering the said sine wave signal to the said first multiplier of said first channel;

means for delivering the said cosine wave signal to the said first multiplier of said second channel;

means for delivering the output of each of the said first multiplier to the said low pass filter and from the said low pass filter to the said second multiplier;

means for delivering a sine wave signal at a second reference frequency to the said second multiplier of said first channel;

means for delivering a cosine wave signal at said second reference frequency to said second multiplier of said second channel;

and summing means for adding the output signals from the said two channels to produce a resultant signal substantially free of components other than the selected frequency;

the improvement comprising matched active low pass filters in the said two channels, each active filter including a pair of series filters each having an operational amplifier having its negative terminal connected to an input terminal through an input resistor and a blocking capacitor in series;

a grounded positive terminal on said operational amplifier;

a feedback resistor connecting the output terminal and the negative terminal of said operational amplifier;

an output capacitor connecting the said output terminal of said operational amplifier with the junction between said input resistor and said blocking capacitor, and a filter output terminal between the said output capacitor and the said junction;

the output terminal of the first filter being connected to the input terminal of the second filter.