Ultrasonic measurement method for lubricating the oil film thickness of diesel piston rings
A good lubrication state at the position of the piston assembly and the cylinder liner friction pair guar-antees stable diesel engine operation and can be judged by the lubricating oil film thickness.Therefore,by considering the lubricating oil film thickness as the measurement target,an experiment was performed to deter-mine the lubricating oil film thickness at the position of the piston ring based on the ultrasonic measurement principle of an equivalent spring model.An experimental platform for the ultrasonic measurement of lubricating oil film thickness was established to verify the measurement ability of the ultrasonic method.A measurement scheme for measuring the lubricating oil film thickness of a diesel engine piston ring was established,and a dy-namic measuring system was designed,built,and applied.By processing the experimental data,the oil film thickness was measured to be 2.2~3.9 μm at the piston ring and increased with rotational speed,confirming the feasibility of the method.