In production, there is often a fever of rolling bearings. If the cause analysis is not clear, the treatment is not timely and the measures are inappropriate, it will take twice the effort and half the effort, and even lead to bearing burnout, gear reducer teeth beating and other malignant accidents. The following is a summary of the specific problems in the design, installation, lubrication, assembly and other links based on several typical cases encountered by the author in the process of production and commissioning, for your reference.
1. Bearing fever due to improper lubrication
1.1 There are congenital deficiencies in the design of lubricating parts of bearings
The excess fan of No. 1 kiln head of ZB Company had many bearing burning accidents in 2003 (the initial stage of commissioning). After on-site investigation, it was found that there was a problem in the oil mark design of bearing base. When the oil level is marked under the oil mark, the actual measurement shows that the lowest row of balls of the bearing has just touched the oil level. Only when the oil level is shown on the upper scale line, can it meet the operation needs. When the oil level approached the lower groove, the lubrication condition deteriorated. At first, the bearing temperature increased slowly. The field personnel did not pay enough attention to the alarm of bearing fever. Once the temperature rose to a certain extent, the bearing would rise sharply and burn out in a very short time. Therefore, incorrect oil labeling will cause misleading to inspection and maintenance personnel. After ascertaining the reasons, the refueling standard line was redrawn.
Another example is the high-speed shaft bearing of CL rotary kiln reducer, which suddenly smokes only 2-3 hours after starting up. The reason for the accident is that the oil return hole in the bearing seat of the high-speed shaft is too low, and most of the oil coming from the oil pipe flows directly from the oil return hole into the reducer. The angle of the oil return hole is adjusted to keep a certain amount of oil in the bearing seat.
After bits, it runs normally.
1.2 Lubricating Oil Pipe Blocked by Foreign Matter
Because the lubrication management is not strict, containers are dirty or pipeline welding pickling is not standardized in the process of oil refueling and oil changing, which results in impurities such as welding slag rust entering the pipeline and blocking oil holes, which is quite common in earlier projects.
For example, ZB's raw material mill reducer is blocked by burning bearings, TH's cement mill reducer is also blocked by cotton yarn, resulting in long-term high temperature bearings and so on. In particular, TH company reducer high-speed axle bearing inspection oil volume, always can not see how much oil can be added to the high-speed bearing, etc. After thorough removal of the tubing with high-pressure air blowing, it was found that there were two thin cotton ropes blocked inside! In addition, TH company also found that the oil hole of the eccentric sleeve of the bearing was too thin (the oil hole of the eccentric sleeve could be one size larger than the oil hole diameter of the bearing itself), so the oil hole was enlarged.
Because the bearings of all parts of hard gear reducer are generally forced lubricated by dilute oil station, and the oil pipes at each lubrication point are in parallel, it is difficult to find the blockage phenomenon of individual oil pipes when observing the total amount of oil and return oil. Therefore, experienced maintenance personnel will carefully check the temperature of each oil pipe and judge it according to the temperature difference of oil pipes. Is the oil pipeline unblocked? Generally, the temperature of oil-free tubing is lower than that of other pipelines.
The inspectors of PY Company have found that the temperature of the oil pipe of the high speed shaft of the reducer in the kiln is low, and finally confirmed the serious hidden danger of the oil pipe blockage, thus avoiding a major accident.
1.3 Lubricating oil (grease) deterioration or oil is not timely
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