Full definition
Condition of excess lubricant in the bearing housing generating mechanical resistance, heat, grease churning and accelerated lubricant degradation. Temperature can rise 15–30°C above normal. Rule of thumb: the free space within the bearing and housing should be filled 30–50% with grease. Excess must be expelled through relief valves or purged during initial start-up. Leading cause of premature bearing failure in improperly lubricated equipment.