Allowable Contact Stress Research Articles

On the Contact Roller Test of Materials Used for Marine Reduction Gears

The author carried out the contact roller test using a testing machine originally designed by the author, in order to find the allowable contact stress (Hertz stress) of materials used for marine reduction gears. The conditions for experiments are as follows; diameter of test rollers=55 and 60 mm, rolling velocity=6.4 and 15.7 m/s with 24% specific sliding, temperature of the turbine oil supplied=46°C. The important results are summerized : The S-N curve and endurance limit of wheel materials in combination of materials of pinion and wheel are considerably affected by the rolling velocity, specific sliding, lubricants and their temperature. The increase of the rolling velocity raises the endurance limit. Pits in existence of specific sliding are produced in a short time as compared with the case of pure rolling. The effect of the high viscosity of lubricant seems to play such a role as the increase of the rolling velocity.