Analysis And Research Of Lubricating Property Based On Electrical Contact Resistance Method

Lubrication is the most effective measure to reduce friction and control wear, meanwhile, it has functions of sealing, noise reduction, refrigeration, cleaning and anticorrosion, etc. Domestic and foreign research data show that the important way of reducing frictional wear and extending the service life of the components is to ensure that friction pairs are in the best lubricating condition. Therefore, only if we study the lubricating oil film in friction pairs and find out the influence regularity which every factor impacts on it can we take measures from all sides to make sure friction pairs are in a good lubricating condition during working process.This thesis studies the lubricating property of Ball-on-Disk friction pair by using electrical contact resistance method. According to experiment requirements, I designed and manufactured a lubricating property testing circuit with strong anti-interference ability, extensive test range and high reliability. I applied the graphic programming software Lab VIEW and compiled a program which can realize the external storage of digital oscilloscope waveforms and motor stepless speed regulation of Ball-on-Disk point contact test-bed at the same time. And I improved the original transmission system of test-bed into synchronous belt transmission system which runs stable at low speed and interfere less. I also studied influence regularity of external load, sliding velocity, lubricant viscosity and roughness of friction pair towards lubricating condition, and obtained the following conclusion:(1) With the change of lubrication conditions (load, sliding speed, lubricating oil viscosity and friction pair surface roughness), the electrical contact resistance show better regularity, which can effectively characterize the lubricating properties of the friction pair.(2) I established relevance curve between average electrical contact resistance and oil film thickness ratioλ, through which we can judge the transition between boundary lubrication condition and mixed lubrication condition rapidly and intuitively, and discriminate which one plays a leading role in the mixed lubrication condition.