The Effects of Additional Factors on the Engine Friction Characteristics

엔진 마찰 특성에 미치는 부수적 인자의 영향

  • 조명례 (현대자동차 파워트레인연구소) ;
  • 김중수 (현대자동차 파워트레인연구소) ;
  • 오대윤 (현대자동차 파워트레인연구소) ;
  • 한동철 (서울대학교 기계항공공학부)
  • Published : 2002.10.01


This paper reports on the effects of additional factors on the engine friction characteristics. The total friction loss of engine is composed of pumping and mechanical friction loss. The pumping loss was calculated from the cylinder pressure, and the mechanical friction loss was measured by strip-down method under the motoring condition. The various parameters were tested. The engine friction loss was much affected by oil and coolant temperature. The low viscosity oil was very effective to reduce the friction loss, and friction modifier was very useful to reduce the friction loss at lower engine speed. The engine friction loss was varied with engine running time because of surface roughness decreasing and oil degradation. To prevent oil-churning effect, it was very important to maintain the proper oil level. The presented results will be very useful to understand friction characteristics of engine.


Friction Loss;Pumping Loss;Mechanical Friction loss;Strip-Down


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