Study On Factors Influencing Film Formation Of Grease

Greases have unique lubricating properties and are widely used under a variety of conditions.However,a wide variety of lubricating greases are important.Choosing the right grease is essential to extend the life of the machine and save energy.The key to study the grease lubrication characteristics and film formation mechanism is to measure the film thickness of the grease under specific conditions.Therefore,it has great theoretical significance and application value for the measurement and exploration of grease film thickness.In this paper,the viscosity-temperature properties of poly-?-olefins are first studied.The results showed that the higher the initial viscosity of the poly-?-olefin oil,the more sensitive the viscosity change with temperature and the worse the viscosity-temperature characteristics.In general,the lower the temperature is,the greater the viscosity of the PAO oil is,and especially when the temperature is lower than 60°C,the initial viscosity has a great influence on the viscosity-temperature characteristics.When the temperature is higher than a certain value,the viscosity-temperature characteristics of the poly-?-olefin oils having different initial viscosities tend to be uniform.Introduced the oil film thickness measurement system.The system uses double interference principle to perform high-precision real-time measurement of grease film thickness.There is a certain vertical distance between the two reflected beams.The thickness of the grease film is this distance,which is the vertical distance between the glass plate and the steel ball.The conditions,consistency,and type of grease selected for the experiment were described.Secondly,the film thickness of point-contact elastohydrodynamic lubrication was studied at low speed.The effects of rolling speed,normal contact load,consistency,and type of grease on film formation characteristics were analyzed.It is concluded that the film thickness increases with the increase of the speed,but the growth rate will decrease.When the rolling speed is constant,the grease film thickness decreases with the increase of the normal contact load;when the rolling speed is one Timing,the smaller the thickness of the grease will be the greater the thickness of the film,on the contrary,the greater the thickness of the grease the smaller the thickness of the film;base oil and thickener on the film formation characteristics of the grease are greater.Based on the analysis of test data,a calculation model for the oil film thickness of lithium-based grease and urea-based grease was proposed.The least squares method was used to fit the test data to obtain the oil film corresponding to lithium grease and urea grease.Thickness exact formula.By comparing the calculated values of the model with the experimental data,we can see that the newly established oil film thickness calculation model can better fit the test data.