A STUDY of the performance characteristics of journal bearings when an abrasive is in the lubricant was undertaken to obtain an indication as to what effect an increase in the viscosity of the lubricant might have on the performance of the bearings of automobile engines when diluted or low-viscosity crankcase-oil is contaminated with road dust or other solid matter.
The general scheme of conducting the tests involves acceptance of the common theory of lubrication of complete journal-bearings and actual operation of bearings under conditions simulating practical applications, with oils of different viscosities and with and without the addition of an abrasive.
During one series of runs, an attempt was made to measure the wear that occurred. The wear on the shaft was practically negligible, but the wear on the bearings was found to have been sufficient to change the average clearance-diameter value from 1/663 at the commencement of the test to 1/597 after the test was completed.
The results are thought to indicate that the factors affecting the wear of journal bearings offer a promising field for further research.