Question 1

What are the advantages of 3-axis measurements over 1-axis measurements?

Accepted Answer

3-axis measurements offer significant benefits in terms of function, flexibility and costs, but in many applications and damage situations, they are not necessarily needed.
Depending on kinematics and machine construction, the stiffness of a machine can be different in intensity and characteristics in the axial, horizontal or vertical direction. 3-axis measurements provide mounting flexibility and capture all three dimensions in a targeted way, taking account of different vibration stimulations.
In addition, certain machine geometries and fault patterns considerably impact the direction of damage evolution. For example, shaft misalignments can be dominant in the axial or radial direction, or unbalance/shocks can have different predominant directions with certain machine geometries.

More about single-axis vs. multi-axis measurement

Question 2

How are the measurement axes calculated and how is the right limit value determined?

Accepted Answer

Thanks to the 3-axis MEMS technology, the sensor can measure vibrations in all dimensions and digitally calculate the overall “magnitude”. The magnitude is the vector addition of more than one axis. For example, the indicator for “fatigue (v-RMS magnitude)” corresponds to the vectorial addition of the X, Y and Z axes. The thresholds for the v-RMS value can be set by system command based on the machine type in accordance with ISO 20816-3. The thresholds for the other characteristic values should be determined empirically over a longer period, e.g. 2 weeks.

Question 3

What error patterns can be monitored with the new VVB IO-Link vibration sensor?

Accepted Answer

Just like the existing VVB IO-Link vibration sensor with one measurement axis, the new VVB relies on the proven damage indicators for detecting fatigue (v-RMS), impacts (a-Peak), friction (a-RMS) and surface temperature as well as the Crest factor in all three axes. This means that different damage scenarios can be derived from a trend increase in a software or controller.
For example, the unbalance analysis functions can be used to detect deposits on rotor blades, build-up on pump blades, or eccentricity in drive motors.
The integrated BearingScout™ function for bearing analysis, which uses a patented algorithm, is ideal for monitoring bearing damage.
Basically all machines with drive shafts, belt drives and largely constant operation conditions (speed and load) can be monitored. The application speed should be greater than 120 rpm. Target applications include centrifugal pumps, ventilation systems, vertical bearings, vacuum pumps, separators and many other single-shaft machines.

Question 4

How exactly does the unbalance and BearingScout™ analysis work?

Accepted Answer

Unbalance: In the basic version, unbalance can be analysed in the sensor. For this, only the speed is required. It can be written to the device statically via IO-Link or dynamically via a PDout signal from the controller. There is a cyclic event in process data flow that signals an exceeded unbalance threshold.

BearingScout™: The DataScience version permits rolling bearing demodulation in addition to unbalance analysis. It enables generic monitoring of the ball bearing in the sensor via an envelope curve analysis. Alternatively, the bearing frequency factors (ordinal numbers) can be configured in the sensor via IO-Link parameters. The BearingScout™ is continuously calculated within a few milliseconds, which provides a distinct advantage compared to conventional envelope curves.

There is a cyclic event in process data flow that signals an exceeded unbalance / ball bearing threshold.

Question 5

Are there any specific software tools required for the new VVB?

Accepted Answer

Any IO-Link parameter setting software, such as ifm’s free software moneo configure, can be used thanks to the standardised IO-Link interface of VVB. Of course, it is also possible to use the data without any additional software by transferring it to the control level via the IO-Link master or to other IT systems via MQTT or HTTPS REST. A Python function library provided in the download section of the product supports easy integration.

VVB 3-axis IO-Link vibration sensor: FAQs