Study On Gear Oil For Off-highway Dump Truck

This paper introduced the development of gear oil of off-highway dump truck, which is used in dump truck gear with low speed and high-load condition. Because of the poor working condition and large concentration of dust as well as the large carrying and high operation, the gears is bearing high pressure and high temperature of gearbox during operation. There has a high requirement on extreme pressure and antiwear property of gear oil as well as oxidation resistance in high temperature. The in-use gear oil cannot meet the requirements on service performance of gear oil, and different degrees of adhesive wear phenomena occurred in the surface of gears. The research must be done to develop a kind of special gear oil used in off-highway dump truck that can meet the requirement on service performance of gear oil during harsh working condition.We can do the development of off-highway dump truck gear oil mainly from two aspects such as base oil and additives. The base oil we use in this paper is Paraffinic Base Oil 600SN, which is made in Ssangyong, and its kinematic viscosity is greater than 10mm2/s in 100 centigrade. And another base oil is 150BS bright stock made in Karamay Petrochemical Company, whose kinematic viscosity is greater than 29mm2/s in 100 centigrade. After being mixed in different proportions we should add Viscosity Index Improver T604A to the mixture. Then we can test the physicochemical indexes of different schemes such as kinematic viscosity in 100 centigrade, viscosity index, open flashing point and pour point. Choose a set of base oil that can meet the requirement of 85W/90 GL-5 gear oil to be the base oil of this test. According to the special working environment and characteristics of off-highway dump truck, the additives we choose is respectively ep antiwear additives, antioxidant, rust inhibitor, emulsion inhibitor and so on. They must be able to improve the performance of gear oil. Some studies were done on sensitivity between additives and base oil as well as compatibility of additives to insure the range of addition amount. And the optimum addition amount determined from orthogonal test.The physicochemical indexes such as kinematic viscosities in 100 and 40 centigrade, viscosity index, open flashing point and pour point were tested with kinematic viscosities testing instrument of petroleum products, Cleveland Open Flash Point Tester and Low Temperature Performance Tester. According to severe wear of transmission gear of off-highway dump truck, the tests were done with four-ball-wear machine and Timken tester to detect antiwear properties and investigate tribological properties of gear oil. In view of the phenomenon of extremely high oil temperature caused by long-time and heavy-load working, we should test the oxidation of development oil through laboratory simulation test, the corrosion resistance through Copper Strip Corrosion Tester as well as demulsibility through Emulsification-resistive Tester.It is showed that, this gear oil used in the dump truck is better than 85W/90 GL-5 gear oil on extreme pressure and antiwear property, high temperature oxidation resistance, corrosion resistance and demulsibility. It can meet the requirements to using performance of off-highway dump truck's gear oil.