Lubrication Characteristics And Experimental Research Of High-speed And Heavy-loaded Rolling Bearings In Aviation Fuel JP-10

With the rapid development of China’s aviation technology,the speed of aircraft engine continues to increase,and the main shaft bearings in aircraft engine always works under high speed,hige temperature and heavy load conditions.Therefore,in order to ensure that the bearings can work reliably within the expected time,it must provide reasonable and effective lubrication for the bearings.To avoid addition of extra auxiliary lubricating devices that could bring certain unexpected impacts such as decreasing the engine system reliability and increasing the manufacturing and running costs,it is preferred to rely on the lubricity of fuel itself to achieve effective lubrication to the main shaft bearings,but the lubricating reliability of the bearings in the fuel is one of the bottlenecks.A type of aircraft engine rotor system intends to use aviation fuel JP-10 to lubricate the main shaft rolling bearings,the research is based on this background.This paper mainly includes the following parts:Establish the point contact partial EHL model and the line contact EHL model based on the rheological properties of JP-10.Using finite difference method to get a numerical solution of point contact partial EHL and using Newton-Raphson method to get a numerical solution of line contact EHL,the distributions of oil film thickness,oil film pressure and rough contact pressure are obtained,which can suggest the lubricity of the fuel JP-10.The lubricating properties of JP-10 and the lubrication states in the bearings are analyzed by the rheological properties of JP-10 and the numerical results.Design and construct the high-speed bearing test rig,which consists of driving system,mechanical system,loading system,lubricating system and data acquisition system.The test rig can simultaneously test the ball bearing 7209 C and the roller bearing Nu208,and the bearings can be tested up to 33000 rmin.The assembly and adjustment of the test rig are accomplished,demonstrating its possibility and serviceability.The data acquisition system based on LabVIEW is established,which is used to monitor the test status and acquire datas.The functions of the system include real-time display of test status,preservation and query of test datas,comparison of multiple test data,temperature alarm and preservation of alarm history and so on.The test of bearing 7209 C and bearing NU208 is carried out in JP-10 under imitative conditions,and get the bearings life by monitoring the failure of the bearings.After the test,using optical microscope to observe the rolling elements and the raceways,analyze the failure mode and offer the test datas and basis for fuel lubrication.The test results show that the lubricating property of JP-10 is very poor,and JP-10 is difficult to provide effective lubrication to the bearings.