Design And Sample Test Of Large Bearing Capacity Isolator Based On Metal Helical Spring

Vibration and noise problems have been paid more and more attention in both industrial production and daily life,and the installation of vibration isolators is one of the main vibration control methods.Nowadays,with the development of technology and the increase of production demand,the power equipment is developing towards the trend of high-speed and large-scale,which leads to a higher demand for the bearing capacity of vibration isolators.There are many kinds of vibration isolators whose performance differs significantly,but high-performance vibration isolators with the advantages of large load,small size,long life and easy to adapt to complex environment still need to be further developed.In this thesis,a new type of vibration isolator with large bearing capacity is designed and developed according to the actual vibration isolation requirements of a pump type power equipment.The research results can provide a new reference for the selection of vibration isolator for large equipment,and the research idea can provide scientific guidance for the design of vibration isolators with limited size and high bearing capacity.The main work and conclusions of this thesis are as follows:(1)The application status of common vibration isolators is investigated,the metal helical spring vibration isolation technology and the helical spring optimal design are summarized,and the research objectives and design methods are introduced.According to the design principle of vibration isolation,the design indexes are obtained for vibration isolation parameters of a pump type power equipment,and the functional structure of a large bearing vibration isolator based on metal helical spring is determined.(2)The optimal design of the vibration isolation spring,as a basic form of composite spring spring,is carried out based on the sequential quadratic programming(SQP)method.After the optimization of spatial arrangement and parameter of the spring,the maximum bearing capacity is increased from 37.9 t to 50 t,with a 32%increase.It can be seen that the optimization method is very reliable.The finite element model of the spring is established,based on which,the stiffness performance and safety strength are analyzed.The stiffness test of vibration isolation spring sample was carried out.From the simulation calculation to the test results,the effectiveness of the optimization design and the consistency of the engineering trial production are fully demonstrated.(3)The structural design and optimization of rubber damping bearing are performed by using empirical formula method,and the finite element calculation based on Mooney-Rivlin hyperelastic model is carried out based on the optimization scheme.After optimization,the stiffness performance has been improved significantly,which is consistent with the test results of rubber bearing.The finite element model under the action of the bearing series spring is established.The dynamic/static stiffness analysis is carried out to obtain the overall stiffness performance of the vibration isolator.The stiffness test under the bearing series is carried out,and the test results meet the design expectations.(4)The structure design of the large bearing vibration isolator including the upper and lower mounting shells is carried out.The overall finite element model is established and the performance analysis is performed.Finally,the sample test is carried out.The stiffness performance analysis shows that the axial static stiffness k_v=14.99 kN/mm and the radial static stiffness k_r=10.12 kN/mm meet the requirements of vibration isolation performance;the safety strength analysis shows that the dangerous stress value of each part of the structure is within the safety strength range of the selected material,which can ensure the safety of vibration isolation under the maximum working load;the vibration isolation effect analysis indicates that the vibration isolation effect is good and the main frequency of the vibration isolation system is 3.7 Hz,which conforms the principle of vibration isolation and has good vibration isolation effect.The bearing and stiffness performance tests show that under the maximum working load the isolator is still in the elastic deformation range,which meets the bearing performance requirements;the axial and radial stiffness increase gradually with the increase of load,the axial stiffness increases to 15.5 kN/mm and the radial stiffness increases to 11.5 kN/mm under the working load,which meets the design requirements.