Determination of babbit fit tightness on split-shell bearings

The technique is based on measurement of scattering magnetic field Нр characterizing residual magnetization distribution in a bearing body. Field Нр measurement can be produced through a babbit layer of the thickness up to 20 mm.

A zone (line) with maximum residual stress concentration (SC zone) is the criteria for determination of parts with potential upset of babbit fit tightness.

The technique is expediently to use in combination with ultrasonic flaw detection. Zones of maximum stress concentration are determined primary by the specialized magnetometers (TSCM-2FP or TSC-type). Then by scanning along SC lines by an ultrasonic instrument gauge (for example thickness gauge) the zone of babbit fit tightness upset is detected.

Fig.1 shows the example of the SC lines location revealed through a babbit layer of the thickness 10 mm on the split-shell bearing.

Fig.1. The example of the SC line location on the split-shell bearing: 1 – zones of babbit fit tightness upset; 2 – SC lines.