Development Of Low Temperature Lubricant Traction Characteristics Testing Machine

Aerospace bearings are usually used in extremely harsh environments,such as low temperature,heavy load,high speed and other operating conditions.The study of the traction characteristics of aerospace bearing lubricants at low temperatures is an indispensable and fundamental basis for the design of such bearing dynamics.In order to study the dynamic performance of lubricants in aerospace bearings,this paper develops a new ball-disc tester for testing the traction characteristics of lubricants under their use conditions based on the high speed ball-disc tester of Henan University of Science and Technology.The tester adds low temperature wide range ambient temperature control device,which can control the ambient temperature in the test chamber above-175℃～room temperature.Improved the support spindle,using air bearing to reduce the base friction torque.Improved the loading system,using servoelectric cylinder for loading,realizing automatic loading.The automatic control technology and program realized the fully automatic measurement,etc.,to suit the aerospace bearing lubricant traction characteristics testing under low temperature conditions.Secondly,this paper simulates and calculates the performance of the important components of the testing machine,such as the load capacity of the air bearing and the base friction torque,analyzes the measurement accuracy of the testing machine,and ensures the stable operation of the testing machine.Finally,the installation and commissioning of each system of the testing machine,as well as the test verification,were carried out.The performance of the low-temperature environment system of the tester was verified by conducting experimental tests using PTFE self-lubricating composite specimens at an ambient temperature of-170°C.Comparative tests were conducted on this tester using the FVA3 reference lubricant provided by Schaeffler,Germany,and the accuracy of the measurement system of the tester was verified by comparing and analyzing the experimental data with the database of the company.The analysis and test results prove that the ball-disk type low-temperature lubricant dragging characteristics tester developed in this paper can load up to 1000 N.The maximum speed of the electric spindle used to drive the ball and disk specimens is48000r/min and 24000r/min respectively,which can meet the need of high-speed sliding and rolling of the ball and disk specimens.The ambient temperature of the test area can be controlled at-175℃～room temperature,and the heating temperature of the lubricant can reach 150℃,which can meet the proposed technical indexes and carry out the test of lubricant dragging characteristics under the conditions of low temperature solid lubrication or oil lubrication.The test machine is stable,and the measured test data are more accurate and reliable,which can provide reliable data support for aerospace series bearing product dynamics analysis and structure design.