Work in the sound characteristics of rolling bearing, only in this way can accurate to judge whether there are abnormal, when the rolling bearing import in the work, is a normal case, stable running, light, no stagnation phenomenon, sound of harmony and no noise, can be heard even and continuous "sound" sound, or lower "rumbling" sound.The intensity of noise is not great.
Now that we know the sound of imported bearings under normal conditions, we can judge the causes of abnormal conditions according to these as the standard:
First, when the inlet bearing is heard to sizzle uniformly and continuously, the sound is produced by the rolling body rotating in the inner and outer diagram, and contains an irregular sound of metal vibration independent of speed.Generally, the bearing grease is insufficient and should be supplemented.If the equipment down time is too long, especially in the cold winter conditions, the inlet bearing will sometimes produce a "hissing and rustling" sound during operation, which is related to the smaller radial clearance of the inlet bearing and the smaller working penetration of grease.The clearance of inlet bearing should be adjusted properly and the new grease with larger needle insertion should be replaced.
Second, when found that the import bearing in the continuous "hua Hua" sound issued a uniform periodic "Ho Luo" this sound is due to the rolling body and the inner and outer ring raceways appear scars, grooves, rust spots and caused by.The period of the sound is proportional to the speed of the bearing.The imported bearings shall be replaced.
Third, when an inlet bearing makes a discrete "stem" sound, the sound is caused by a break in the retainer or inner ring.Must stop immediately to replace the import bearing.
Fourth, when found import bearing from irregular and uneven "scrape" the sound is due to the import bearings into the iron filings, sand and other impurities.The sound intensity is small and has no connection with revolutions.Bearings should be cleaned, regreased or changed.
Fifth, see the work of the import bearing out of a continuous and irregular "rustle" this sound and the import bearing with the inner ring and shaft with too loose or the outer ring and bearing hole with too loose.When the intensity of sound is high, the bearing should be checked, and the problem should be repaired in time.
C. Requirements for using electronic stethoscope for monitoring
(1) During the monitoring process, similar monitoring points or monitoring points with close working conditions should be selected for sound comparison as far as possible. Any abnormality found should be treated as a defect and must be thoroughly checked.For a single device, in order to overcome the disadvantage of non-comparability, the sound recording at the monitoring point under normal condition can be used as the basis for comparison in future monitoring.
(2) To correctly select the position of the monitoring point, the vibration direction to be measured should be consistent with the sensor's sensitive direction, so that the measurement direction is the direction with the maximum vibration intensity.The sensor should be at right angles to the measured surface, and the error should be controlled within 10°.
(3) The measuring surface shall be clean and level, without rust or paint, and the concave part shall be polished to make it smooth and level.
(4) The measuring force of the pressure probe should be 10-20n.