Abstract: Rotating gap oil duct is the main structure of a vehicle’s transmission lubrication system. However, when the transmission system rotates at a high speed, due to the effect of external forces, there is a risk of the insufficient oil supply. Therefore, it is necessary to investigate the influence of various parameters on the flow characteristics of the rotating gap oil duct in the lubrication system of the transmission. In this study, a theoretical model of the flow rate of the rotating gap oil duct is proposed, and the lubrication mechanism and flow characteristics of the rotating gap oil duct are discussed. The effects of the oil temperature, the inlet pressure and the rotating speed on the lubrication oil flow field are analyzed. The lubricating oil flow test is carried out using the rotating gap oil duct test rig for the transmission lubrication system. It is found that with the increasing input shaft speed, the oil flow at the three groups of the radial outlets near the inlet increases slightly, while the oil flow at the gap outlet decreases significantly; with the increasing inlet pressure, the oil flow at each outlet increases, but the flow at the gap outlet increases more significantly. The test results are consistent with the theoretical calculation results, indicating the effectiveness of the theoretical calculation method for the flow rate in the rotating gap oil duct. The proposed method provides a theoretical basis for the accurate oil supply design of the transmission lubrication system.

Key words: vehicletransmission, rotatinggapoilduct, flowcharacteristic, testofrotatinggapoilduct