Process and device for testing electric motors, in particular fan motors, for functionality

• US 7,079,039 B2
• Filed: 12/15/2003
• Issued: 07/18/2006
• Est. Priority Date: 12/13/2002
• Status: Expired due to Fees

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Gruhle, Andreas, Kibbel, Horst
• Primary Examiner(s): Mullen, Jr., Thomas J.
• Assistant Examiner(s): Walk, Samuel J.
• Application Number:
  US10/736,469
• Publication Number:
  US 20040124844A1
• Time in Patent Office: 946 Days
• Field of Search: 340/648, 361/687, 361/688
• US Class Current: 340/648
• CPC Class Codes: G01R 31/343 in operation

Abstract

The invention concerns a device for and a process for testing electric motors, in particular fan motors, for functionality, wherein electromagnetic alternating fields produced by an electric motor are received by an antenna, wherein the received signals are analyzed for signal components in the frequency range of the rotation value of electric motors or their harmonics via an analysis unit, and wherein upon determination of functionality the results are indicated by an indicator unit.

Claims

1. A device for testing electric motors for functionality, said device including:

an antenna for receiving electromagnetic alternating fields generated by the operation of said electric motor;

an amplifier for amplification of the received signal,

an analog-digital converter for converting the received signal into a digital signal,

a unit for analysis of the received signals for signal components in the frequency range of the rotation value of electric motors or their harmonics, said unit for analysis being a device for digital signal processing and including a bandpass filter unit with a bandpass width corresponding at least partially to the conventional prevalent frequency range of the rotation values of electric motors or the harmonics thereof, and

an indicator unit for signaling functionality.

2. A device as in claim 1, wherein said electric motor is a fan motor.

3. The device according to claim 1, wherein the filter unit includes multiple switchable bandpass filters with bandpass widths corresponding to the frequency ranges of the rotation values of varying electric motors or their harmonics.

4. The device according to claim 1, wherein the indicator unit emits an acoustic signal.

5. The device according to claim 1, wherein said device includes a portable housing.

6. The device according to claim 1, wherein said device includes an independent energy source.

7. The device according to claim 6, wherein said independent energy source is a battery or a fuel cell system.

8. The device according to claim 1, wherein the device for digital signal processing is a microcontroller, a signal processor or an ASIC.

9. A device for testing electric motors for functionality, said device including:

an antenna for receiving electromagnetic alternating fields generated by the operation of said electric motor;

a unit for analysis of the received signals for signal components in the frequency range of the rotation value of electric motors or their harmonics, said unit including a bandpass filter unit with a bandpass width corresponding at least partially to the conventional prevalent frequency range of the rotation values of electric motors or the harmonics thereof and an analog/digital converter subsequent to the antenna and wherein the unit for analysis of the received signal is a device for digital signal processing;

an amplifier for amplification of the received signal between the antenna and the unit for analysis; and

,

an indicator unit for signaling functionality, wherein the antenna includes one or more receiver coils.

10. The device according to claim 9, wherein the receiver coils are oriented in differing spatial directions.

11. A device according to claim 9, wherein

the filter unit includes a filter with a bandpass width of approximately from 1 Hz to 1 kHz.

12. A device for testing electric motors for functionality, said device including:

an antenna for receiving electromagnetic alternating fields generated by the operation of said electric motor;

a unit for analysis of the received signals for signal components in the frequency range of the rotation value of electric motors or their harmonics, said unit including a bandpass filter unit with a bandpass width corresponding at least partially to the conventional prevalent frequency range of the rotation values of electric motors or the harmonics thereof and an analog/digital converter subsequent to the antenna and wherein the unit for analysis of the received signal is a device for digital signal processing;

an amplifier for amplification of the received signal between the antenna and the unit for analysis; and

an indicator unit for signaling functionality,

wherein the bandpass filter includes a filter with a bandpass width of approximately from 100 Hz to 1 kHz.

13. A device according to claim 12, wherein

the filter unit includes a filter with a bandpass width of approximately from 100 Hz to 10 kHz.

14. A process for testing an electric motor, comprising:

placing an antenna which receives alternating electromagnetic fields in the vicinity of an electric motor which in operation generates alternating electromagnetic fields,

analyzing via an analysis unit the received signal for signal components in the frequency range of the rotation value of the electric motor or their harmonics, and

in the case that the analysis for functionality is positive, indicating this result via an indicator unit.

15. The process as in claim 14, wherein said electric motor is a fan motor.

16. A process as in claim 15, wherein said analyzing comprises

pre-determining the characteristics of the direct emission signature of a rotating functional electric motor to be tested,

detecting the alternating electromagnetic fields in the vicinity of a motor to be tested, and

comparing said detected signal with said predetermined signal.

17. A process as in claim 15, wherein said electric motor is installed in a vehicle, wherein said vehicle has at least first and second electric motors, and wherein subsequent to analysis of said first electric motor said antenna is moved to the vicinity of said second electric motor and said process is repeated.