System for monitoring bearings and other rotating equipment

• US 4,237,454 A
• Filed: 01/29/1979
• Issued: 12/02/1980
• Est. Priority Date: 01/29/1979
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Meyer, Leslie D.
• Primary Examiner(s): Caldwell, Sr., John W.
• Assistant Examiner(s): Nowicki, Joseph E.
• Application Number:
  US06/007,573
• Time in Patent Office: 673 Days
• Field of Search: 340/682, 340/683, 340/539, 340/58, 73/593, 73/659, 73/DIG. 4, 325/185, 310/323
• US Class Current: 340/682
• CPC Class Codes: F16C 19/527 related to vibration and noise
• CPC Class Codes: F16C 41/004 Electro-dynamic machines, e.g. motors, generators, actuators
• CPC Class Codes: F16C 41/008 Identification means, e.g. markings, RFID-tags; Data transfer means
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis
• CPC Class Codes: G01N 2291/2696 Wheels, Gears, Bearings
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: Y10S 73/04 Piezoelectric

Abstract

A self-powered monitor unit with a tuned mechanical resonator power unit and a radio transmitter is mounted on every piece of rotating equipment being monitored, such as machinery with ball bearings. Bearing vibrations are sensed and the generation of a defect signal triggers the transmission of a radio signal modulated to identify the source. A central station receives and demodulates an emitted radio signal and displays the location with a fault condition. Large numbers of equipment can be monitored conveniently by unattended units.

Claims

1. A system for monitoring rotating machinery at many locations and communicating a fault condition to a central station, said machinery inherently having a fundamental unbalance component of machine vibration, comprising:

a self-powered monitor unit removably mounted on every piece of machinery on a stationary structure thereof at a position to sense structure-borne vibrations;

each monitor unit including a tuned mechanical resonator for generating electrical power which operates at the rotational frequency of the machinery and is driven by the fundamental unbalance component of machine vibration;

a power conditioner for converting the generated electrical power;

a vibration sensor for sensing said structure-borne vibrations and continuously producing an electrical vibration signal;

signal processing circuitry for continuously processing said vibration signal and producing a defect signal upon the occurrence of a fault condition; and

radio transmitter circuitry triggered by said defect signal for transmitting to the central station a radio signal that uniquely identifies the piece of machinery with a fault condition;

said tuned mechanical resonator comprising a cantilever beam and an attached piezoelectric element;

said power conditioner being connected to said piezoelectric element and supplying electrical power to said signal processing circuitry continuously so long as said machinery is rotating and to said radio transmitter circuitry only upon triggering by said defect signal.

2. The system of claim 1 wherein the radio transmitter circuitry of all monitor units has the same carrier frequency but a different modulating frequency that identifies every piece of rotating equipment;

and wherein the system further includes a radio receiver, a demodulator, and a fault locator apparatus at the central station for receiving and demodulating the radio signals from all monitor units and displaying an identification of the faulty machinery.

3. The system of claim 1 wherein each monitor unit has a permanent magnet for removable mounting on the piece of machinery.

4. A system for monitoring roller element bearings in rotating machinery at many locations for fault conditions comprising:

a self-powered monitor unit removably mounted on every piece of machinery on a stationary structure thereof at a position to sense structure-borne vibrations emanating from the bearing;

each monitor unit including a tuned mechanical resonator for generating electrical power which operates at the rotational frequency of the machinery and is driven by the fundamental unbalance component of machine vibration;

a power conditioner for converting the generated electrical power;

a vibration sensor for sensing the bearing vibrations and generating an electrical vibration signal;

a bearing monitor circuit for continuously processing said vibration signal and producing a defect signal upon the occurrence of a fault condition;

radio transmitter circuitry triggered by said defect signal for transmitting to the central station a radio signal that uniquely identifies the piece of machinery with a fault condition;

said power conditioner being connected to said mechanical resonator and supplying electrical power to said bearing monitor circuit continuously so long as said machinery is rotating and to said radio transmitter circuitry only upon triggering by said defect signal; and

a receiver and fault locator apparatus at a central station for receiving the radio signals and displaying an identification of the faulty machinery.

5. The system of claim 4 wherein said tuned mechanical resonator is comprised of a cantilever beam and an attached piezoelectric element.