Machine monitor

• US 5,852,351 A
• Filed: 08/20/1997
• Issued: 12/22/1998
• Est. Priority Date: 08/22/1996
• Status: Expired due to Term

• Current Assignee: Computational Systems Incorporated (Emerson Electric Company)
• Original Assignee: CSI Technology Incorporated (Emerson Electric Company)
• Inventors: Robinson, James C., Canada, Ronald G., Pardue, Eugene F.
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US08/915,069
• Time in Patent Office: 489 Days
• Field of Search: 318/490, 318/430, 318/432, 361/23, 364/550, 364/556, 364/557
• US Class Current: 318/490
• CPC Class Codes: G01R 31/343 in operation
• CPC Class Codes: G01R 33/028 Electrodynamic magnetometers
• CPC Class Codes: G07C 3/00 Registering or indicating the condition or the working of machines or other apparatus, other than vehicles
• CPC Class Codes: H02K 11/0094 Structural association with other electrical or electronic devices
• CPC Class Codes: H02K 11/20 for measuring, monitoring, testing, protecting or switching rectifiers H02K11/04; power electronics H02K11/33
• CPC Class Codes: H02K 11/25 Devices for sensing temperature, or actuated thereby
• CPC Class Codes: H02K 11/35 Devices for recording or transmitting machine parameters, e.g. memory chips or radio transmitters for diagnosis

Abstract

A monitor attaches to a mount proximate a machine to determine the health and operating status of the machine. The monitor is preferably self-contained, having its own internal power source, electronics, and sensor suite. One or more sensors are provided to sense machine operating characteristics such as temperature, flux, and vibration. Sensor outputs are processed and analyzed by monitor electronics to determine various operating parameters, including machine speed and load, which are stored in memory. Other parameters which can be calculated and stored include cumulative time of machine operation for different categories of loads, cumulative time of machine operation over a predetermined maximum temperature, and total number of machine starts. Monitor electronics are also operable to transform time domain data generated by the sensors to frequency domain data. A communications port enables a peripheral device, such as a notebook computer or portable data collector, to communicate with the monitor and download stored data. Downloaded data can be further analyzed and statistically compared to trend data at a base computer to further ascertain the health and condition of the machine. For purposes of prolonging the life of the internal power source, the monitor electronics are configured to consume very little power.

Claims

1. A monitor that attaches to a mount proximate a machine for monitoring operation of the machine and producing an operation history, said monitor comprising:

a structural enclosure;

an engagement surface formed on said enclosure;

a fastener for attaching said engagement surface to the mount;

a power supply for supplying electrical power to the monitor;

at least one sensor for sensing one or more sensed parameters of the machine and producing sensor signals corresponding to the one or more sensed parameters;

a signal processor disposed in said enclosure for receiving and processing sensor signals and for performing a Fourier transform of the sensor signals to produce information corresponding to the operating parameters;

memory for storing information corresponding to the operating parameters, said stored information corresponding to the operation history of the machine; and

an output port for outputting at least the stored operation history of the machine.

2. The monitor of claim 1 wherein said signal processor is programmed to produce a spectrum having a frequency band as a result of performing said Fourier transform of sensor signals.

3. The monitor of claim 1 wherein said operating parameters include machine speed which is determined by the signal processor from sensed parameters.

4. The monitor of claim 1 wherein said operating parameters include machine load which is determined by the signal processor from sensed parameters.

5. The monitor of claim 4 wherein said operating parameters include cumulative time of machine operation for different categories of loads.

6. The monitor of claim 1 wherein said operating parameters include total number of machine starts.

7. The monitor of claim 1 wherein said at least one sensor includes a temperature sensor for sensing machine temperature and producing a temperature sensor signal which is received by the signal processor and used to determine an operating parameter corresponding to cumulative time that the machine has operated over a predetermined maximum temperature.

8. A system for monitoring the condition of one or more machines, the system comprising:

for each of said one or more machines, at least one monitor attached proximate to the machine, said at least one monitor including;

a structural enclosure;

an engagement surface formed on said enclosure;

a fastener for attaching said engagement surface to the mount;

a power supply for supplying electrical power to the monitor;

at least one sensor for sensing one or more sensed parameters of the machine and producing sensor signals corresponding to the one or more sensed parameters;

a signal processor disposed in said enclosure for receiving and processing sensor signals and for performing a Fourier transform of the sensor signals to produce information corresponding to the operating parameters;

memory for storing information corresponding to the operating parameters, said stored information corresponding to the operation history of the machine; and

an output port for outputting at least the stored operation history of the machine.

9. A system in accordance with claim 8, further comprising a computer for receiving and analyzing the downloaded operation history, producing information corresponding to the operating condition of said one or more machines.

10. A system in accordance with claim 8, further comprising a portable data collector for downloading the stored operation history of said one or more machines.

11. A system in accordance with claim 8, further comprising:

a portable data collector for downloading the stored operation history of said one or more machines; and

a computer for receiving and analyzing the downloaded operation history, producing information corresponding to the operating condition of said one or more machines.

12. A modular unit that attaches proximate to a motor to detect and store information corresponding to speeds at which the motor has been operated, said unit comprising:

a structural enclosure;

an engagement surface formed on said enclosure;

a fastener for attaching said engagement surface proximate the motor;

one or more sensors for sensing one or more parameters of the motor and producing sensor signals corresponding to the sensed parameters, said at least one or more parameters corresponding to at least motor speed;

a signal processor disposed in said enclosure for receiving and processing the sensor signals to produce motor speed data;

a storage device for receiving and storing motor speed data over time to produce an operation history of the motor;

an output device for outputting at least the stored operation history of the motor; and

a power supply for supplying electrical power to the unit.

13. The unit of claim 12 wherein said one or more sensors include a vibration transducer for sensing vibration generated by the motor during operation.

14. The unit of claim 12 wherein said one or more sensors include a flux sensor for sensing flux generated by the motor during operation.

15. The unit of claim 12 wherein said one or more sensors include a flux sensor for sensing flux generated by the motor and a vibration transducer for sensing vibration generated by the motor.

16. A modular unit that attaches proximate to a motor to detect and store information corresponding to loads at which the motor has been operated, said unit comprising:

a structural enclosure;

an engagement surface formed on said enclosure;

a fastener for attaching said engagement surface proximate the motor;

one or more sensors for sensing one or more parameters of the motor and producing sensor signals corresponding to the sensed parameters, said at least one or more parameters corresponding to at least motor load;

a signal processor disposed in said enclosure for receiving and processing the sensor signals to produce motor load data;

a storage device for receiving and storing motor load data over time to produce an operation history of the motor;

an output device for outputting at least the stored operation history of the motor; and

a power supply for supplying electrical power to the unit.

17. The unit of claim 16 wherein said one or more sensors include a vibration transducer for sensing vibration generated by the motor during operation.

18. The unit of claim 16 wherein said one or more sensors include a flux sensor for sensing flux generated by the motor during operation.

19. The unit of claim 16 wherein said one or more sensors include a flux sensor for sensing flux generated by the motor and a vibration transducer for sensing vibration generated by the motor.

20. A recorder that attaches proximate to a motor to detect and store information corresponding to motor operation, said recorder comprising:

a structural enclosure;

an engagement surface formed on said enclosure;

a fastener for attaching said engagement surface proximate the motor;

at least one sensor for sensing one or more parameters of the motor and producing sensor signals corresponding to the sensed parameters, said at least one or more parameters corresponding to motor load;

a clock for producing a clock signal;

a signal processor disposed in said enclosure for receiving and processing the sensor and clock signals to produce motor load data and to produce data corresponding to cumulative time of motor operation at a plurality of motor load categories;

a storage device for receiving and storing motor load data and cumulative time of motor operation at each motor load category to produce an operation history of the motor;

an output device for outputting at least the stored operation history of the motor; and

a power supply for supplying electrical power to the recorder.

21. The recorder of claim 20 wherein one of said plurality of motor load categories is cumulative time of motor operation at over 100 percent of rated load.

22. The recorder of claim 20 wherein one of said plurality of motor load categories is cumulative time of motor operation in the range of 80 to 100 percent of rated load.

23. The recorder of claim 20 wherein one of said plurality of motor load categories is cumulative time of motor operation over a predetermined maximum motor frame temperature.

24. A modular unit that attaches proximate to a motor to detect and store information corresponding to total number of motor starts, said unit comprising:

a structural enclosure;

an engagement surface formed on said enclosure;

a fastener for attaching said engagement surface proximate the motor;

a sensor for sensing a parameter of the motor and producing sensor signals corresponding to the sensed parameter, said sensed parameter corresponding to motor start;

a signal processor disposed in said enclosure for receiving and processing the sensor signals to produce motor start data;

a storage device for receiving and storing motor start data over time to produce an operation history of the motor;

an output device for outputting at least the stored operation history of the motor; and

a power supply for supplying electrical power to the unit.

25. The modular unit of claim 24 wherein said sensor includes a flux sensor for sensing magnetic flux generated by the motor.

26. The modular unit of claim 24 wherein said sensor includes a vibration sensor for sensing mechanical vibrations generated by the motor.

27. A recorder that attaches proximate to a motor to detect and store information corresponding to motor operation, said recorder comprising:

a structural enclosure;

an engagement surface formed on said enclosure;

a fastener for attaching said engagement surface proximate the motor;

at least one sensor for sensing one or more parameters of the motor and producing sensor signals corresponding to the one or more sensed parameters;

a clock for producing a clock signal;

a signal processor disposed in said enclosure for receiving and processing the sensor and clock signals to produce data corresponding to cumulative time of motor operation at each of a plurality of motor operating categories;

a storage device for storing cumulative time of motor operation at each motor operating category to produce an operation history of the motor;

an output device for outputting at least the stored operation history of the motor; and

a power supply for supplying electrical power to the recorder.

28. The recorder of claim 27 wherein one of said plurality of motor operating categories is cumulative time of motor operation at 100 percent of rated load.

29. The recorder of claim 27 wherein one of said plurality of motor operating categories is cumulative time of motor operation in the range of 80 to 100 percent of rated load.

30. The recorder of claim 27 wherein one of said plurality of motor operating categories is cumulative time of motor operation over a predetermined maximum motor frame temperature.