Sensor enables condition monitoring of grease in rolling bearings
A novel sensor that enables the online condition monitoring of grease in rolling bearings has been developed by The Schaeffler Group.
The new device is designed to monitor critical plant and machinery located in difficult-to-access areas, such as wind turbines and automated assembly lines.
According to Schaeffler, it incorporates a unique electronic evaluation system that enables the condition of the grease to be monitored whilst the bearings are operating.
The sensor is positioned directly in the rolling bearing immersed in the grease, meaning any changes in its condition are detected early, before any damage can be caused to the bearings.
The grease sensor measures 5 x 40mm and is able to detect four parameters of grease; water content, cloudiness (opacity), wear (thermal or mechanical) and temperature.
From these parameters, the sensor's electronic evaluation system utilises complex software algorithms to generate an analogue signal (4 to 20mA), which then displays the condition of the grease.
By setting alarm thresholds (limit values), digital signal outputs can also be generated, indicating whether the grease quality is 'poor' or 'good'. The user can decide at which point in the condition of the grease (from 100% for as-new, to a theoretical 0% for an unusable grease) relubrication or grease replacement should be carried out.
A further solution is currently being developed by the company for integration of the sensor in rolling bearing seals.
