Bearing replacement cycle: When should it be replaced?
In the operation of industrial equipment, bearing failure is often a gradual process. According to research data from the American Society of Tribologists and Lubrication Engineers (STLE), about 34% of bearing failures are caused by improper lubrication and 21% are caused by contaminants. Mastering the scientific replacement timing judgment method can help equipment managers extend the service life of bearings by more than 30%.
1. 6 major danger signals that must be replaced immediately
1. Analysis of abnormal noise characteristics
When the bearing makes a regular "click" sound, it usually indicates that the rolling element is peeling; continuous hissing sounds indicate insufficient lubrication. When using a sound level meter for detection, if the noise value increases by more than 15 decibels compared to the baseline data, the replacement threshold is reached.
2. Abnormal temperature increase
The normal operating temperature should be 30-50℃ higher than the ambient temperature. When using an infrared thermometer for detection, if the outer ring temperature exceeds 90℃ or the temperature rise rate is greater than 5℃/hour, there is a risk of lubrication failure. A case of an automobile manufacturer shows that timely replacement of wheel hub bearings with abnormal temperature avoided a potential production line shutdown and significant losses.
2. Four key factors affecting bearing life
1. Load characteristics
Impact loads can shorten bearing life by 40-60%. For equipment such as mining crushers, it is recommended to multiply the theoretical calculated life by a working condition factor of 0.7. The actual service life of a vertical mill bearing in a cement plant was 42% shorter than expected. After analysis, it was mainly due to dynamic load changes caused by material particle size fluctuations.
2. Key points of lubrication management
When using a centralized lubrication system, the amount of grease added should be 1/3 of the internal space volume of the bearing. Excessive grease will cause stirring heat, which will shorten the service life. A wind power company has increased the MTBF (mean time between failures) of the main shaft bearing from 18,000 hours to 25,000 hours by optimizing the lubrication cycle.
3. Three professional suggestions for extending bearing life
1. Preventive maintenance plan
Establish a maintenance calendar based on the number of operating hours, and key equipment bearings need to be tested for clearance every 2,000 hours. When using a dial indicator to measure, replacement is required when the radial clearance exceeds the initial value by 25%. After a papermaking company implemented preventive maintenance, the cost of bearing replacement was reduced by 37%.
2. Application of condition monitoring technology
The use of vibration analysis technology can predict bearing failures 3-6 months in advance. When the vibration speed value reaches 4.5mm/s (ISO10816 standard), a planned replacement should be arranged. A petrochemical company successfully avoided a million-dollar loss caused by compressor bearing jamming through an online monitoring system.
3. Professional installation specifications
When using hydraulic nuts for installation, the taper deviation of the mating surface must be controlled within 0.01mm. Data from a bearing manufacturer shows that correct installation can make the bearing life reach 90% of the theoretical value, while improper installation can cause a life loss of up to 60%.
Through scientific detection methods and maintenance strategies, companies can significantly improve the use efficiency of bearings. If you find any of the warning signs mentioned in this article, it is recommended that you contact our technical team immediately for professional diagnostic services. We will provide customized bearing solutions.