상용 디젤 엔진 터보챠져의 오일 유막두께와 트러스트 포스의 상관관계에 대한 연구

Abstract

An experimental study was carried out to calculate oil film thickness of turbocharger and to know relationship with thrust capacity. Pressure sensor and temperature sensors are installed on turbocharger and engine for measurement. Engine runs 1900RPM and 2200PRM with engine loads and without engine loads. Three test modes are selected as FF, FP, FA considered actual engine usage. Tested turbochargers were installed 3 pads thrust bearing and 6 pads thrust bearing for each to compare thrust force and oil film thickness at same test condition. Theoretical value for minimum oil film thickness of thrust bearing is verified with system properties and used base value to compare with actual tested value. Test results were shown that 6 pads thrust bearing oil film thickness is 35 thicker than 3 pads thrust bearing due to thrust capacity of thrust bearing. That is verified all test modes. Total thrust force measurement result is same of 3 pads thrust bearing and 6 pads thrust bearing, that reason is thrust force is proportionate to thrust bearing pads area but increased thrust force work to each compressor and turbine side. 6 pads thrust bearing has more thrust capacity, so that can have more oil film thickness under same thrust force. In this study, how determine minimum oil film thickness based on theory and it can be verified thrust capacity of turbocharger is related to oil film thickness in actual usage condition. Also it was verified which factor can effect to oil film thickness on turbocharger.