Bearing life is basically divided into fatigue life, service life, wear life, fault life. 1. Fatigue life: the main moving parts of the bearing material reached the limit, resulting in the accumulated bearing time before failure. Rated dynamic load: life expectancy of 10000 rpm, the bearing can withstand the load. Equivalent dynamic load: refers to the actual load bearing in accordance with determine the dynamic load operating conditions converted assumed load. 2. Service life: refers to the above-mentioned three types of life-span general reference, in theory it refers to the bearing fatigue life, performance under normal conditions of wear bearing life, in the condition is not normal, no defects in the manufacture, on behalf of the fault life . 3. Wear life: bearing wear due to normal, increased clearance to the limit before the cumulative working hours. In terms of today's bearing industry, wear life> fatigue life, but in fact traction motor on the contrary. 4. Fault life: Bearing failure, is the loss of working ability before the cumulative working hours. And bearing lubrication and bearing life and then what is the relationship, take a look at the purpose of bearing lubrication we all know: The purpose of bearing lubrication: 1. To extend the fatigue life of bearing rolling fatigue life, rotation, the rolling contact surface lubrication is good, then extend. This is the biggest advantage of lubricating bearings, can increase the fatigue life and extend bearing life. 2. To reduce friction and wear In the composition of the bearing rings, rolling elements and retainers contact with each other to prevent metal contact, reduce friction and wear. 3. Discharge friction heat, cooling cycle to the oil law, etc. can be used to discharge the oil generated by the friction heat, or by external heat, cooling. Prevent bearings overheating, to prevent the lubricant itself aging. 4. The other is the same with lubricating bearings can also be foreign intrusion into the bearing's internal, or to prevent bearing rust, corrosion effect.