Method for assessing the vibration behavior of an electric motor, and corresponding electric motor and fan

1 . A method for assessing a vibration behavior of an electric motor, such as an electric motor of a fan, and/or its operating environment, comprising:

generating recorded vibration values by recording vibrations of at least one part of the electric motor at a plurality of different frequencies by means of a vibration sensor,

ascertaining a first assessment measure for the recorded vibration values, wherein the first assessment measure is representative of a strength of the vibrations of the at least one part of the electric motor across the plurality of different frequencies,

determining a spectral component of the recorded vibration values for an assessment frequency,

ascertaining a second assessment measure for the spectral component of the recorded vibration values, wherein the second assessment measure is representative of a strength of the vibrations of the at least one part of the electric motor at the assessment frequency,

identifying the assessment frequency as a resonance point when a ratio of the second assessment measure to the first assessment measure exceeds a predetermined limiting value, and

adjusting a setting of a regulation system of the electric motor when the result of the identifying step indicates that the assessment frequency is a resonance point.

2 . The method according to claim 1 , wherein the assessment frequency is formed by an order of a base frequency of the electric motor.

3 . The method according to claim 2 , wherein a first order is used as the assessment frequency to determine whether the assessment frequency is a resonance point caused by unbalance.

4 . The method according to claim 2 , wherein the base frequency is dependent on a speed of the electric motor.

5 . The method according to claim 1 , wherein the determining, ascertaining a second assessment measure, identifying and adjusting steps are repeated for multiple assessment frequencies.

6 . The method according to claim 1 , wherein a detected resonance point is additionally assessed at least by one of comparing an amplitude and/or an effective value of a strength of the recorded vibration values with a predetermined amplitude limiting value, ascertaining a vibration shape, and ascertaining a vibration mode.

7 . The method according to claim 1 , wherein the method is performed during at least one of: when the electric motor is commissioned; during ongoing operation of the electric motor; after a predefined time span has elapsed; and when an operating parameter of the electric motor is changed.

8 . The method according to claim 1 , further comprising generating a suggestion for mitigating negative effects of a resonance point when the assessment frequency is identified as a resonance point.

9 . The method according to claim 8 , wherein the suggestion includes a location and/or extent of a balancing mass and/or a suppression corridor.

10 . The method according to claim 1 , wherein the predetermined limiting value is at least one of: greater than or equal to 50%; greater than or equal to 60%; and

greater than or equal to 70%.

11 . The method according to claim 1 , wherein at least one of the first and the second assessment measure is ascertained by forming an effective value of a strength of the recorded vibration values.

12 . An electric motor, comprising:

a vibration sensor which is designed to record vibrations of at least one part of the electric motor and to generate recorded vibration values at a plurality of different frequencies,

a first assessment unit which is designed to ascertain a first assessment measure, wherein the first assessment measure is representative of a strength of the vibrations of the at least one part of the electric motor across the plurality of different frequencies,

an analysis unit which is designed to determine a spectral component of the recorded vibration values for an assessment frequency,

a second assessment unit, which is designed to ascertain a second assessment measure for the spectral component of the recorded vibration values, wherein the second assessment measure is representative of a strength of the vibrations of the at least one part of the electric motor at the assessment frequency,

an evaluation unit which is designed to identify the assessment frequency as a resonance point when a ratio of the second assessment measure to the first assessment measure exceeds a predetermined limiting value; and

a regulation system that is designed to adjust regulation and/or control of the electric motor when the assessment frequency is identified as a resonance point.

13 . The electric motor according to claim 12 , wherein the vibration sensor is designed to at least one of: record vibrations along multiple axes, wherein the multiple axes stand perpendicular to one another in pairs and wherein one of the multiple axes is arranged parallel to a motor axis/motor shaft of the electric motor, record a vibration speed and/or record a vibration acceleration.

14 . The electric motor according to claim 12 , wherein the electric motor comprises an output device which is designed to output information about any identified resonance points, wherein the output device can be designed to upload the information into a cloud system.

15 . The electric motor according to claim 12 , wherein the analysis unit is designed to carry out a Fourier transformation, an FFT—Fast Fourier Transform—and/or a Görtzel algorithm and/or frequency band filtering.

16 . A fan, comprising an impeller and an electric motor according to claim 12 , wherein the impeller is coupled to a rotor of the electric motor.

17 . A system with an operating environment and a drive, wherein the drive comprises a fan according to claim 15 , wherein the operating environment interacts with the drive and wherein the drive is designed to record and assess both vibrations of the drive and vibrations in the operating environment.

18 . The fan comprising an impeller and a motor, wherein the fan is configured to carry out a method according to claim 1 .