Condition monitoring of machines

 Finishing of optical glasses


The fine processing of optical glass requires highest precision. Disturbances caused by imbalance and bearing damage must be avoided at all costs.


Determination of adequate monitoring parameters and their permanent monitoring with the condition monitoring solution VibroLine.

Product: VibroLine VLE series (1- 8 channel)


In order to guarantee a permanently high processing quality during the production of lenses, machines should be permanently monitored with regard to imbalances and bearing damage.

To determine appropriate monitoring parameters, a pre-investigation was carried out on the machines using the condition monitoring of machines measuring kit. Various error conditions were simulated. The analysis revealed the following monitoring variables:

Unbalance monitoring: By using the speed signal provided by the machine, an order characteristic value of 1:1 was defined. This monitors the oscillations at speed, which reflect the unbalance.

Bearing monitoring: Combined monitoring of peak value and effective value in the frequency band 15 ... 40 kHz. The characteristic value parameterized in this way is also called 1/K(t) and shows increasing values with increasing bearing damage.

In the course of the preliminary investigation, limit values were also defined for warning and shutdown of the corresponding maximum allowed unbalances and for the bearing condition.


These limit values were then saved for continuous monitoring in the VibroLine condition monitoring system. Thus, the vibration condition could be continuously checked over the further running time of the machine. From now on, the operator was informed as soon as the warning threshold was reached or the machine was stopped as soon as the shutdown threshold was exceeded. The digital output of the devices made it easy to integrate the alarm for exceeding the limit value into the machine control system.