펌프 동력 소모에 기반한 엔진오일의 실시간 점도 계측 기법에 관한 연구

Abstract

Real-time measured engine oil viscosity may be utilized as an index whether an engine-related actuator is operational and also as an element on estimation of remaining lifespan of engine oil. Nevertheless, development of in-situ oil viscosity sensors is not an easy task due to severe environments of engine lubrication system. In order to measure viscosity of engine lubrication system, a sensor must fulfill numerous qualifications including real-time measurement, robustness and installability. A pump may be applied for such a sensor since a pump may be operated under severe conditions and that its power consumption varies with viscosity of its working fluid. Based on this concept, this research mainly focuses on development of a real-time viscosity measurement sensor by measuring power consumption of a pump. Centrifugal and gear pumps were used along with a number of methods concerning improvements on resolution and range of viscosity to be measured, including adjustment of outlet load condition and redesign of pump impeller. Experiments were performed to measure change in torque applied to pump with varying viscosity along with sensitivity and range of viscosity to be measured. Finally, a DC motor was connected to examine change in current with varying viscosity under fixed voltage. The current changed along with viscosity variation as expected, which verifies functionality as an engine oil viscosity sensor.

Key words : Engine oil, viscosity, real time measurement, pump, power consumption.