| Bearing as a mechanical parts,which has the role of supporting or guiding function,has a significant role in modern mechanical equipment.And the journal bearing has been widely used in large-scale equipment with its high bearing capacity,strong impact resistance and good vibration absorption and other advantages.With the mechanical equipment moving towards to the high speed,high power,high automation and environmental protection,the bearing working conditions and environment has become increasingly harsh,which put forward higher requirements on the lubrication technology of journal bearing.Oil air lubrication(OAL)as a kind of advanced lubrication technology has better effect on environmental protection,controllability,lubrication,can meet the requirement of the development of mechanical equipment.This thesis takes OAL technology of journal bearing as research subject,with the method of combining theory and experiment,studied the technical problems related to the application of OAL technology on the journal bearing lubrication,namely the correlation problem of two-phase flow pattern and pressure drop in OAL transmission pipeline and the jet cooling mechanism of journal bearing of OAL.The thesis' s main content is as follows:(1)Established the mathematical model of fluid lubrication of journal bearing.Analyzed the relationship between supporting capacity and eccentricity ratio,the minimum oil film thickness,leakage amount and drag coefficient of finite journal bearings.And calculated the design parameters and oil film under different speed.Through analyzing the principle of fever of journal bearing,established the calculation model of jet cooling.And analyzed the jet cooling effect of nozzle diameter and jet distance.Providing theoretical support for the journal bearing lubrication.(2)Designed oil and air two-phase flow pattern and pressure drop experiment station.Studied the effects of gas pressure,fuel supply and pipeline diameter on the two-phase flow pattern and pressure drop by using the orthogonal experiment method.The main influencing factors of pressure drop is the pipeline diameter and the main influencing factors of two-phase flow pattern formed annular flow is the gas pressure.(3)Built the body part of the high-speed journal bearing test bench.According to the required factor of oil film temperature,oil film pressure,oil film thickness and friction factor,developed its experimental device and data acquisition supporting the experiment.(4)Studied the journal bearing of lubrication and cooling effect in low speed.By measuring the friction torque and temperature,carried on contrast experiment of the oil lubrication and OAL lubrication of journal bearing,the different jet forms of journal bearing and the different bearing structures of OAL lubrication experiment.The experimental results show that the OAL lubrication can complete lubricating the journal bearing.And the temperature of the condition of OAL lubrication is obviously lower than the oil lubrication condition.The cooling effect of 2mm column jet form is slightly better than the other forms of jet cooling.The cooling effect of journal bearing which open slot is better than the common journal bearing and the journal bearing which have channel. |
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