What are typical causes of bearing overheating?

The main causes of bearing overheating typically stem from excessive load, inadequate lubrication, and misalignment. Excessive load places a strain on the bearing, causing it to generate excess heat due to increased friction. When bearings are not lubricated sufficiently, either due to lack of lubrication or degraded lubricant, the necessary film that prevents metal-to-metal contact disappears, leading to increased friction and heat generation.

Misalignment occurs when the bearing is not installed in perfect alignment with other components, leading to uneven wear and increased friction. This misalignment can also contribute to uneven load distribution, further exacerbating heating issues. As a result, the combination of these factors can lead to critical overheating, which can damage the bearing and surrounding machinery.

The other choices detail various conditions that would not logically lead to bearing overheating. For instance, low temperatures and low loads generally do not contribute to overheating; instead, they may allow bearings to operate more efficiently. High humidity and poor material quality can cause other types of failures or degradation but are not direct causes of overheating in a typical usage context.