Service life of motor bearings
Thread Content
Regarding the usage and maintenance cycle for the bearings of ordinary chemical process pump motors (20–200 kW), should they be replaced immediately upon hearing any abnormal noises (in cases where a backup pump happens to be faulty and there’s no time to replace it, this often affects production), or should they be replaced on a scheduled basis every 2–3 years (given that the repair work is extensive and costly)? How do people address this issue?
We are no longer in an era of using scheduled maintenance; at the very least, it’s predictive maintenance now. Take some time to learn more about equipment failure diagnosis!
The question raised by LZ is actually quite representative; although predictive maintenance is being practiced by everyone, the phenomena mentioned by LZ do indeed exist in practice. Any advanced approach has its shortcomings. Could combining predictive maintenance with regular inspections help to minimize the factors that affect production? Let’s discuss this!
This requires continuous monitoring; online testing is the most effective method. If any abnormalities are detected, it can still be used for about three more months. Therefore, regular maintenance is very important, as is conducting periodic inspections. It’s not necessary to specify how often it needs to be changed. Generally, the bearings should be replaced when the vibration reaches 0.030 mm
This is a fairly typical issue; in such cases, it is necessary to strengthen inspections, keep proper records, and conduct thorough analysis. If there are no significant changes over a short period, the component can continue to be used; however, if there are substantial changes, it should be addressed during the next scheduled shutdown
The backup must be available at any time; the key lies in managing its use.
I often encounter situations like the poster’s, but here we prioritize production, and any maintenance work is constantly postponed
To transition from reactive repair to predictive maintenance, the designed service life of bearings is generally 17,500 hours. Motors, on the other hand, require maintenance such as cleaning, lubrication, and clearance measurement every 1 to 2 years. This helps to extend their service life. An optimal vibration level is below 0.03 mm; a good level is below 0.04 mm, while 0.06 mm is considered acceptable. If the vibration level exceeds 1.2 to 1.5 times the acceptable threshold, the equipment cannot operate for long periods, as this can lead to its damage.
In actual operation, vibration is difficult to detect; maintenance personnel can make judgments by listening and feeling, as abnormal sounds can serve as an early indicator.
My opinion is: 1. Regular inspections should be thorough; since inspections of the equipment are carried out frequently, any abnormalities in the equipment can be detected quickly. 2. That is, during each maintenance check, it is necessary to inspect the condition of the lubricant in the bearings, as this allows one to assess the operating condition of the bearings. 3. It’s not necessary to replace components according to their specified service life; otherwise, most devices would need to be replaced, and the factory’s maintenance department would not approve that. Modern component designs have a certain limited lifespan, but that represents only the minimum guaranteed operating time – it’s not necessarily the time when the component will fail. Therefore, as long as regular inspections are carried out carefully, signs of problems can be detected before they occur in the equipment.