Numerical Simulation Of Bearing Cleaning Nozzle Flow Field And Study On Particle Removal Effect

With the developing of China’s industrial technology,the demand for bearings is increasing.Bearing accuracy and running flexibility are important index for assessing bearing quality.If there are dust particles or other contaminants inside the bearing,with the running of bearing,it is very easy to cause raceway wear.At the same time,it will produces noise and abnormal sound.,which will seriously affect the performance of the bearing.At present,most of the cleaning equipment of the bearing automatic assembly line needs to be constantly changed and it is very inconvenient to use.In this article,a cleaning device with good cleaning effect,high degree of automation and no need to replace tooling is developed.The main research contents are:Based on the analysis of domestic and international cleaning technology and jet research,For the 6204 deep groove ball bearing,a device integrating bearing cleaning and grease injection is designed.Using modular design concept,the whole equipment is divided into main function module and auxiliary module.The main function modules include cleaning mechanism,micro-motion mechanism and grease injection mechanism,which is used to achieve the cleaning and even grease injection of bearings.The auxiliary function modules include:Transport mechanism and shifting mechanism,mainly responsible for the transfer of bearings.For the special structure of the cleaning device,the Fluent software is used to simulate the flow field of the cone straight nozzle,based on B-spline curve,a new type of nozzle is designed and analyzed.The following conclusions are drawn:for the cone straight nozzle,the influence of jet velocity factors from large to small are the diameter,the contraction angle,and the outlet length.At the same time,changing the shape of the outlet also has a great influence on the nozzle flow field.For the B-spline nozzle,the factors affecting the jet velocity from large to the small are the exit area,length-diameter ratio,and the length of the inlet section.Through the above analysis,the nozzle structure and the target distance which are most suitable for cleaning the bearing are selected,and a bearing cleaning device is designed.The change of flow field was analyzed according to the difference of inlet position,nozzle distance and number,and two inlet cleaning devices are found(Whether the inlet is on the upper side or the lower side),Its velocity is higher than that of nozzles with non-inlet and nozzles with only one inlet.Inlet in the middle,the bearing pressure distribution is relatively uniform.From the view of nozzle distance,the inner and outer ring pressure distribution is relatively more uniform when the nozzle distance is 34 mm.Changing the number of nozzles does not affect the nozzle exit velocity,which affects the nozzle inlet velocity.The larger the number of nozzles,the larger the inlet velocity and flow rate.It is easy to cause uneven cleaning when the number of nozzles is small.When the nozzles are set up five,there is a blind area for cleaning.Finally,four nozzle cleaning devices are selected.Finally,the gas-solid coupling simulation of Fluent and EDEM software is used to solve the problem of cleaning particles in bearings,The following conclusions are drawn from the simulation of the cleaning the bearing surface and the inside of the raceway.The smaller the particles,the fewer the particles falling into the bearing.Some of the particles fall on the upper surface of the bearing and relatively less into the bearing channel.The smaller the diameter of the particles,the higher the cleaning efficiency.