(V) Case Study- Effect of Lubrite Treatment on Hypoid Gear set Performance

Lubrite has its own function to do in Hypoid gear set manufacturing process. Typically the gear set used in lighter & heavy axles are treated with Lubrite (Mn –Iron Phosphate) to minimize the initial damage on gear tooth surface while initial start running of vehicle. The accessibility of Axle oil will take a while to reach the every tooth profile of gears while initial start running of vehicle because there is will not be enough turbulence inside the axle. Since the shallow gear ratio has lower contact stress & deeper gear ratio has higher contact stress , considered 4.88 & 5.83 gear ratios with & without Lubrite for the study . The Mechanism of Lubrite coating discussed. 3 Samples each Lubrited & Non-Lubrited for Both the Gear Ratios are tested for Gear set Fatigue Block cycle validation. All these axle samples run up to certain block cycles & test suspended. Post validated both Gear Ratio gear sets are examined for surface imperfection like scoring mark or if any other marks. The axle samples are subjected to cleaning specification confirmed before bench validation. The outcome of validation shows the Lubrite samples show no damage for both the gear ratios & non- Lubrite samples of deeper Gear ratio 5.83 show scoring marks on the surface of the gear tooth. Based on this evaluation & shallow gear ratio are having the lower contact stress than the deeper gear ratios, decided to use Non Lubrite gear set in Shallow ratios particularly less than 5 & Lubrite gear sets are used for deeper gear ratio above 5. This study compares the performance of Lubrite & Non Lubrite coated Gear sets & shows the important of Lubrite treatment in deeper gear ratios. Shallow Gear ratio can have option for Lubrite coating based on the Gear Design