One of the main requirements of gearboxes is to establish when the oil needs to be changed.
One of the parameters is the oil acidity index, which is obtained through laboratory analysis and indicates that the oil must be changed because it is becoming degraded. When this reaches a value of “one” over the value of the oil when it was new, it needs to be changed. This parameter provides valuable information and is a good indicator for performing predictive maintenance.
Another possibility is to find out the state of the gearbox oil obtaining the remaining life of the oil by monitoring the antioxidant additives and by the voltammetry technique.
This technique provides data on the remaining life of the oil in a few minutes. It is a proactive technique and it is used to monitor new generation oils in service.
Through the analysis known as RULER (Remaining Useful Life Evaluation Routine) the remaining useful life of the oil is quantitatively determined by measuring the levels of antioxidant additives it contains.
The rate of wear of the antioxidants over time is monitored and is used to predict the appropriate intervals for changing the oil. In addition, it shows “abnormal” operation of the unit before it breaks down.
The recommended analysis frequency is six months. Maintaining this frequency enables us to establish clear predictive maintenance criteria.
Finally, it is important to select the sampling points correctly. This is a critical factor when studying the trends of the results and the analysis of the particles in the oil to know when it is necessary to change it.