A Systems Approach to Determining Actual Misalignment and Load Distribution for Cylindrical Roller Bearings in Commercial Gear Trains

The Contact Pattern Analysis technique was used to determine the actual distribution of load among rollers, misalignment, and roller edge loading effects in cylindrical roller bearings in a commercial gear train. In all the bearings in the system, the summation of the vertical components of individual roll body loads determined from Contact Pattern Analysis agreed well with the total load imposed on the bearing by the system, thereby demonstrating the practicability and accuracy of the technique. In a few cases the load distribution among rollers in the bearing and, in one case, the number of rollers loaded, were found to be far from ideal. Similarly, it was found that the direction of the bearing reaction differed significantly from the applied load direction. The misalignment as calculated from the contacts was .003 to .005 mm/mm. Also, evidence of contact truncation and roller edge loading at peak torque loads were found. Thus this systems approach, utilizing the Contact Pattern Analysis technique revealed several anomalies that suggest adjusting system parameters, such as housing stiffness and/or roller crown, to improve bearing reliability and performance. This could not have been done by any other known analytical technique.