| In recent years,the almost polishing on the surface of the bend tube is carried out by hand operation.But,manual labor is not only difficult to ensure the products qulity also the hostile environment is harmful to human's healthy.In this case,BeiJing RuiDuFang company united with Tsinghua university developed an automatic production line in allusion to polish the bend pipe in 2015.The line was finished in August 2016,after come into use,it greatly improved the efficiency of polishing bend pipe and created a good market economy efficiency.However,the wheelhead in the production line main unit caused severed vibration and great noise,which seriously affected the environment of the production field and the equlity of products.In order to solve this problem,based on the analysis of the wheelhead's structure and working theory,confirmed that the main parts of the grinding head vibration focus on the gear system.Therefore,solving the vibration of the gear is the key of vibration and noise reduction for wheelhead.The paper studies the gear system of the automatic production line developed by BeiJing RuiDuFang company and established the three-dimensional finite element model of gears and the whole grinding head.It is concluded that the normal model of gear from level 1 to level 6 by use of ANSYS software.Meanwhile,a dynamic model of wheelhead gear transmission system was built and showed the dynamic differential equation based on the dynamic theory and the second Lagrange equation,and solving differential eqution by use of Newmark numerical analysis and concluded that gear transmission error is the main source of grinding head vibration and noise.The error caused the relative displacement between the gear pairs as result of changing gears meshing force which makes the wheelhead cause vibration and noise.In the end,by stucture improvemen of the wheelhead for achieve the effect of vibration damping and noise reduction,and do experiments to contrast the nosie level before and after improvement.The test results show that with the increase of motor speed,the noise level also amplifies.When improve the speed of motor to 1450 r/min,the noise reaches a maximum 95.33 dB.However,after the structure improves,the maximum noise is 72.34 dB.The nosie decibel value is down 24.12%.The main work in this paper includes:1.Introduction to the main structure of the automatic production line,and mainly introduces the composition structure and working principle of grinding head;2.To establish three dimensional finite element models of gears and grinding head,modal analysis was carried out on the model by use of ANSYS software;3.Buliding a dynamic model of gear system,and make dynamics analysis to the gear system.4.Making the structural optimization to grinding head,by measuring the grinding head improvement before and after improvement noise sound pressure level to verify the correctness of the improved scheme,finally reach the purpose of reducing vibration and noise. |
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