Bearing lap running means that the rolling bearing and its matching shaft or hole have a relative sliding.

First, fault phenomenon: bearing part temperature is high, vibration is large.Open to see, the inner ring surface of the shaft and bearing seat has sliding-marks, and even the surface of the shaft or hole is worn out of the groove.From this case it has been concluded that bearings run laps.

Bearing lap running has a very large negative impact on the equipment, which aggravates the wear and tear of matching parts, and even charges, damages the equipment and reduces the precision of the machine. In addition, it increases the friction force, converts a lot of energy into useless heat energy and noise, and reduces the efficiency.Therefore, this situation, should be based on the actual situation, as soon as possible to arrange maintenance.

Two, the reasons for running laps:

The matching of bearings and shafts (holes) requires very strict requirements on the machining accuracy, matching tolerance, installation and assembly accuracy, material, and use and maintenance of shafts, holes and bearings. Any aspect is not good enough to make bearings run in laps.

1, fit tolerance: bearing and shaft (hole) fit tolerance has strict standards, different specifications, accuracy, stress status, use environment, etc., different requirements for fit tolerance.The friction between the rolling body and the inner and outer sleeve of the bearing is rolling friction. The friction coefficient of the two contact surfaces is very small, and the friction force is very small (when there is lubricating oil between the rolling body and the inner and outer sleeve, the friction coefficient will be smaller).Bearing and shaft (hole) with very tight, generally for interference fit, a few cases for transition fit.The mutual extrusion pressure is large, producing static friction, static friction force is greater than the torque that makes them relatively sliding, so the bearing and shaft, hole can remain relatively static, and by the rotation of the rolling body and the inner sleeve (or between the coat) transfer mechanical energy.If the fit tolerance of bearing and shaft and hole slants big, for clearance fit, the extrusion pressure decreases, axis (bearing) under the effect of torsion, the static damage to each other, sliding, we call it "run laps phenomenon" happened, bearing inner ring with the axial sliding said within laps, sliding bearing outer ring and bearing hole happen according to run outside.

2, machining accuracy, installation accuracy: refers to the shaft, bearing, bearing seat hole machining work difference, surface roughness, installation and assembly accuracy and other technical parameters.These countries also have industry standards.Once the standard is not reached, it will affect the tolerance and cause the bearing to run in the lap.The matching position of the shaft and the bearing requires that the surface is very smooth, and the roughness Ra is less than or equal to 1.6μm. If it is greater than this, the burr will be pulled out in the disassembly and assembly process of the bearing, causing the shaft to become thinner, the hole to become larger, the matching clearance to become larger, and the reasonable tolerance to fit will be destroyed.Again, such as, installation of the coaxial degree is not enough, can make large bearing vibration, shaft bending, load is bigger, cause, increase the number of replacement of bearings, bearing failure of bearing and shaft or hole size tolerance, thereby undermining its fit tolerance with axis (hole), all of this is likely to cause bearing run laps and bearing failure.

3. The material of shaft and bearing is also very important.Different kinds of bearings should be made of corresponding bearing steel, with large strength and stiffness, good wear resistance and small friction coefficient of bearing alloy, so as to ensure the normal use of bearings and reduce the possibility of running laps.

4. Daily maintenance:

(1) The coupling and its wearing parts are seriously worn, and the out-of-tolerance of coaxiality and concentricity will destroy the installation degree.

(2) The locking parts of the bearing, such as the locking mother, clamp ring and end cover, are not locked in place, which damages the matching accuracy of the bearing.

(3) poor lubrication, increased ball wear, increased temperature, uneven thermal expansion of bearings and matching parts, also destroy the matching accuracy.

(4) When the bearing is disassembled and assembled, it is not standardized, the shaft or bearing is damaged, and the matching accuracy is destroyed.

(5) poor fastening of bearing seat anchor bolts causes vibration, which is also the reason for damage to bearings.