The Development of Methods for the Ultrasonic Inspection of Bearings

摘要

The special Ultrasonic Inspection technique coded MC sub 3 is particularly suited for bearing inspection, due to the ability to control its depth of scan, thereby restricting the inspected region. In this manner, inspection can be concentrated on the segment of the raceway which experiences the major sub-surface shear stresses during bearing operation. Using the MC sub 3 technique, the inner and outer raceways of 100 ball bearings were inspected prior to assembly. The inspection data was analyzed and the bearings were ranked in order of probability of failure. Following testing, a re-inspection was performed on a number of long-life, unfailed bearings in order to determine whether the MC sub 3 inspection could also detect incipient sub-surface failures. A statistical analysis of the test data shows that the MC sub 3 inspection is capable of sorting out those bearings which are likely to fail in the early portion of life. It cannot as yet, however, do this on a completely reliable basis. MC sub 3 inspection presently also tends to reject some bearings with long potential. Until, the reliability can be more absolute, the MC sub 3 method cannot be recommended for immediate application as a quality control measure. Means to improve reliability are being developed and these are discussed. (Author)