If the operating temperatures are significantly high and can vary between 120 ° C and 150 ° C, or if the rotational speeds are above 1,500 rpm, it is advisable to use mineral oil to perform proper lubrication. The oils have lubricating properties appropriate to the working conditions. On low power engines, initial lubrication in the assembly is provided in a way that ensures a high amount of operating hours. In some cases, the grease reserve may be sufficient for the entire life of the device. On large engines there is a need for external lubrication. The frequency of lubrication varies according to the design of the bearings and the specifications of the lubricants used.
Thus, it is important to be aware that at a temperature in the average of 40 ° C, the life of a continuously running ball bearing may be approximately three years or even longer. However, for every 10 ° C increase in working temperature the durability decreases by an average of 50%. Proper lubrication of the bearings, in addition to improving performance, can prevent temperature rise which reduces the durability of such equipment.