Research On The Structure And Lubrication Performance Of The Compressor Crankshaft Bush

During the compressor working process,crankshaft bearing is under complex alternating mechanical load and heat load,and performance and reliability of the bearing seriously affect the compressor overall performance.Crankshaft bearing is not only born the alternating load under the combined action of gas pressure,reciprocating inertia force and the gravity of crankshaft.But in the friction condition,it will lead to deterioration of lubrication conditions,bearing lubrication properties have deteriorated and bearing wear intensified.In this paper,the crankshaft bearing of split double acting compressor is taken as the object of study.The structure and working principle of the crankshaft connecting rod lubrication system are described in detail.The force of the bearing system is analyzed by establishing the theoretical model,based on the theory of fluid lubrication the lubrication characteristics of the bearing can be simulated.Determine the best operating parameters of the work of the bearing in the model structure and choose the best crankshaft bearing structure,which lays a theoretical foundation for the application of bearing engineering.Specifically include the following:First,the specific structure of the crankshaft connecting rod lubricating oil circuit is explained and its lubrication principle is expounded.The basic equations of hydrodynamic lubrication can be deduced by the hydrodynamic theory.The theoretical calculation formula of bearing capacity of lubricating oil film can also be obtained by calculating the bearing capacity coefficient of oil film.By analyzing factors affecting the lubricating oil film,and specifying the bearing simulation analysis direction.Second,doing research on mechanical behavior of the crankshaft bearing,calculating the gas force and inertial force at different crank angle,and then getting the link force.Eventually,the magnitude of the external force exerted on the crankshaft bearing is achieved.The dynamic curve of the simulation model can be obtained by using the dynamic simulation of SolidWorks Motion to analyze the dynamics of the crankshaft bearing system.It is easy to verify the theoretical calculation of the bearing rod force is correct,which provides a theoretical basis for the design and optimization of crankshaft bearing structure.Third,based on fluid computational mechanics,the three-dimensional model of oil film was established.By Fluent fluid simulation,to analyze the influence of model structure on bearing lubrication in different aspect ratio,speed,inlet pressure,offset angle and minimum oil film thickness.And on this basis,the optimal parameters of the compressor lubrication are obtained to guide the operation of compressor unit.Last,based on the study of the mechanical behavior of the bearing pads and the analysis of the lubrication,the maximum stress and amplitude of the crankshaft are taken as the main analysis indexes.The bearing structure can be optimized when the target value reaches the minimum or optimum value.So the use of bearings to achieve the best results and it will be regarded as theoretical guidance for the application of bearing in engineering.