| The power of the air conditioner refrigeration system comes from the compressor,and the vibration of the compressor is the main source of vibration and noise of the air conditioner.The noise generated by the vibration of the air conditioner compressor seriously affects the comfort of the air conditioner,and easily causes fatigue damage to the pipeline system connected to the compressor,and affects the reliability of the air conditioner.To improve the overall performance of the air conditioner,it is necessary to conduct in-depth research on the vibration characteristics of the air conditioner compressor.This topic expands the compressor rubber isolation pad from the static characteristic analysis to the dynamic characteristic analysis,and perfects the dynamic characteristic model of the rubber isolation pad.On this basis,the introduction of thermal oxygen aging influencing factors reveals the dynamic characteristics of rubber isolation pad with the degree of thermal oxygen aging of the rubber isolation pad,and improves the prediction accuracy of the dynamic characteristics of rubber isolation pad for better the optimized rubber isolation pad design provides theoretical support.It provides a theoretical and experimental basis for further design,matching and parameter optimization of the rubber isolation pad in the whole machine.The main research of this paper is as follows:(1)Based on the hyperelastic model,the fractional derivative model and the Coulomb friction model,the dynamic characteristic model of rubber isolation pad at room temperature is established.Finite element analysis was used to combine with the static stiffness experiment results of rubber isolation pad,a hyperelastic model is established.And the linear static characteristic model of rubber isolation pad was revised,which greatly improved the accuracy of hysteresis loop characteristics.The fractional derivative model and the Coulomb friction model are introduced to describe the frequency dependence and amplitude dependence of the rubber isolation pad dynamic characteristic,the dynamic characteristics of the rubber isolation pad are theoretically modeled and analyzed.According to the designed rubber isolation pad samples,an experimental platform for static and dynamic characteristics was built.The experimental results show the correctness and accuracy of the built rubber isolation pad dynamic characteristics model.(2)Based on the thermal oxygen aging factor,the dynamic characteristic model of thermal oxygen aging of rubber isolation pad was established.The influence of thermal oxygen aging on the dynamic characteristics of rubber isolation pad is discussed,and it is pointed out that the thermal oxygen aging factor is an indispensable key parameter that affects the dynamic characteristics of rubber isolation pad.With a hardness change of 5degrees as the test termination condition,the rubber isolation pad was subjected to a thermal oxygen accelerated aging test.The hardness-related Peck model introduced on the basis of the Arrhenius model further improves the accuracy of the thermal oxygen aging factor.The thermal oxygen aging factor is combined with the dynamic characteristic model of rubber isolation pad at room temperature,the thermal oxygen aging dynamic characteristic model is established.The static and dynamic characteristics of the rubber isolation pad after thermal oxygen aging were tested.The experimental results show that after the thermal oxygen aging changes of the rubber isolation pad by 5 degrees,the static stiffness of the rubber isolation pad increases by 20.7% and the dynamic stiffness increases by 4.5%.At the same time,it is also proved that the built thermal oxygen aging dynamic characteristics model can more accurately describe the frequency dependence,amplitude dependence and thermal oxygen aging dependence of the rubber vibration isolation pad after thermal oxygen aging.It provides theoretical support for the dynamic characteristic evolution law of the vibration isolation pad that takes into account the thermal oxygen aging due to the external environmental temperature.The test method for the vibration characteristics of the compressor vibration isolation system is given,and the vibration characteristics of a certain fixed frequency and a certain inverter air conditioner compressor with rubber isolation pads before and after thermal oxygen aging were tested.A test platform for vibration characteristics of air conditioner compressor was built by using home air conditioners and corresponding test instruments,the test method and steps are given.The test results show that after the thermal oxygen aging of the rubber isolation pads,the compressor vibration characteristics will deteriorate to different degrees,and the maximum value of the vibration acceleration is 100%,which verifies the necessity of considering the thermal oxygen aging of the rubber isolation pad.(3)The research on the optimization of the stiffness matching of rubber vibration isolation feet is carried out.Through the analysis of the natural frequency and vibration mode of the compressor vibration isolation system,the structure and decoupling design of the system were optimized by theoretical analysis.Commercial software such as Solid Works,Hyper Mesh,ABAQUS and ADAMS were used,and vibration isolation and energy decoupling with reality were combined,the best matching plan for compressor vibration isolation system is selected.Through the vibration characteristics test,it can be seen that the stiffness matching optimization design effect of the rubber isolation pad is better,which verifies the feasibility of the stiffness matching of the compressor vibration isolation system.At the same time,it also explains the severity of the change in the stiffness of the rubber isolation pad after thermal oxygen aging.After the rubber isolation pad have increased by 5 degrees in thermal oxygen aging hardness,the maximum increase in static and dynamic stiffness is 20.7% and 4.5%,respectively.The maximum decrease in the loss factor is 10.6%.Thermal oxygen aging changes the rationality of the original rigidity matching of the rubber isolation pads,the original vibration isolation performance is destroyed,and the vibration of the compressor vibration isolation system was caused to increase.The established dynamic characteristics model and the thermal oxygen aging dynamic characteristics model further improve the modeling method of rubber isolation pad,greatly improve the prediction accuracy of rubber isolation pad dynamic characteristics,and the correctness and accuracy of the model are verified by static and dynamic characteristics experiments,vibration property tests,etc.The stiffness matching design of compressor vibration isolation system was carried out by using topology optimization and decoupling optimization design,and the feasibility and rationality of stiffness matching were verified by vibration characteristic test. |
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