In industrial manufacturing the automation of production processes has become a core factor and robots play a key role in improving productivity, availability and safety. In this prospective, unexpected robot downtime or failure may not only affect daily production tasks, but also cause unpredictable additional production and economic losses. Reliability and availability of the robots is therefore crucial in such systems and a careful maintenance based on condition monitoring of the actual operational health status of the machine has become to play a vital role in order to avoid unscheduled breakdowns, wasteful replacement or repairs before the end of the Remaining Useful Life (RUL) of components.