Rolling bearing

A sensor on the bearing or bearing housing continuously measures vibration and usually temperature as well. Software compares the values with limit values or with the known normal state. If the vibration pattern changes, the system issues a warning, at Magna for example as a traffic light in the dashboard and as an alarm by smartphone or email. Maintenance can then schedule the bearing replacement instead of waiting for a failure.

Bearing failure usually announces itself through changing vibration and rising temperatures long before it can be heard. Sensors detect these changes early, together with related faults such as imbalance, shaft misalignment or loose machine parts. The drive current can also provide clues: at Novoferm, current curves indicate wear in ball bearings or belts before a total failure occurs.

Bearing faults are detected early when the machine is measured permanently rather than only during inspection rounds. On laser cutting machines, Codestryke uses a retrofitted sensor box that measures vibration, magnetic field, acoustics and temperature. A cloud analytics application determines the condition of the components at any time. After a fault, it is immediately clear whether a bearing is damaged and which bearing it is.

Suitable vibration sensors can be retrofitted without changing the control system and transmit their data themselves. In the solution examples, these are compact sensor boxes such as Arrow's iCOMOX, mounted inside or outside the machine, and ifm vibration sensors with evaluation in the field. Many drives already have temperature and vibration sensors on board, and according to Innomotics, missing ones are easy to retrofit.