Research On Temperature Limit Of Ring Groove Based On Piston Ring Lubrication Failure

The friction loss of cylinder liner-piston ring friction pair occupies a large proportion of the total friction loss in diesel engine.The piston,especially the overtemperature of the first ring groove,can make the friction and wear of cylinder liner-piston ring friction pair more severely,it can also lead to cementation phenomenon of piston ring after long time operation,this will seriously affect the normal work of the diesel engine.Reasonable control temperature can avoid scuffing of piston ring and cylinder liner,which is lead by coking phenomenon.This also prevents failure due to excessive wear of ring grooves and piston rings.Therefore,the study of temperature change rule of the upper limit value of piston ring groove under different conditions is significant.In this paper,the ring grooves temperature limit is the research object.Electric motor is applied to drive diesel engine.Floating cylinder method is used to measure the friction of the cylinder liner-piston ring.Simulation backpressure loading method is used to exert pressure on piston ring.The flame is used to heat the top of the piston,which simulated the thermal load in the work.Based on the above,an experimental provision was built and used for study of experimental.At the same time,the heating system,temperature measuring system,data acquisition system are improved.Based on the failure of lubrication of cylinder liner-piston ring friction pair,the temperature limit of piston ring groove is analyzed,which give support to the material design of piston and piston ring,as well as the thermal damage inhibition of piston and piston ring.The friction of cylinder liner-piston ring and piston ring groove temperature were measured respectively,by changing the intensity of cooling and heating strength,replace the lubricating medium,change the friction pair materials,a preliminary analysis was made on the relationship between cylinder liner-piston ring friction and the temperature of the piston ring groove,the results showed that,under the experimental conditions of this paper:(1)When the cooling water flow rate is 20L/min,40L/min,60L/min respectively,under the same heat intensity,lubrication medium and the friction pair,the piston ring grooves temperature limit is 205℃.Change the cooling intensity had no effect on the temperature limit of piston ring groove.(2)When the heating rate is 1℃/s and 2℃/s respectively,under the same cooling intensity,lubricating medium and the friction pair,the piston ring grooves temperature limit is 205℃.Change the heating intensity had no effect on the temperature limit of piston ring groove.(3)When the lubricating oil is 10W-30 and 15W-40 respectively,under the same cooling intensity,heating strength and the friction pair,the piston ring grooves temperature limit is 200℃ and 205℃ respectively.(4)When the cylinder liner is chrome-plating,and piston rings are chrome-plating,CKS,spraying molybdenum respectively,under the same cooling intensity,heating strength and lubricating medium,the piston ring grooves temperature limit is 205℃,210℃ and 200℃ respectively.