Noise And Vibration's Optimization Of Rotary Compressor

The article expatiates an improving process about the air-condition compressor′s noise and vibration。The article optimized noise and vibration focusing on a single rotor rotary compressor capable of variable frequency。According to Japan APF condition′four kinds of tests,measuring noise and vibration,finding the problem:At the cold and warm rate condition,base frequency′s 5 multiple frequency peak value(300-400Hz)。At the warm rate condition,1200Hz peak value。Tangential acceleration is universal higher。Analyze these problems,do the motor noise test,varied pressure and revolution test,parts natural frequency calculation and measure,noise and vibration allocation test,find abnormal situations as below:(1) Cold and warm rate condition′s five multiple base frequency source is motor magnetic noise,and it is close to pump natural frequency,so lead to bigger noise ; (2) Warm rate condition′s 1200Hz noise is induced by motor too。And it is close to accumulator 2,3 step modal,excite bigger noise。(3) Tangential acceleration has higher peak,think the reason is unstable rotary condition。So according to single rotor compressor characteristic,redesign the motor rotor-shaft rotary system。Above all , increase the motor rotor-shaft rotary system natural frequency to reduce the five multiple base frequency noise at cold and warm rate condition,increase the accumulator natural frequency to reduce 1200Hz noise at warm rate condition。Among the process of optimizing the vibration,by founding motor-shaft system,bearing system′s FEM model and discretization design。Resolve element form function (change infinite dimensional question to finite dimensional question)。Utilize rotor dynamics knowledge,get element mass matrix,gyro matrix,stiffness matrix。Using virtual work principle to change external force to equivalent node vector,finally get dynamics expression。Create FEM model of bearing film,use fluid Reynolds equation′s variational form,to equal equation of variation to minimum problem,via divide rectangle cell to get form function。Resolve film cell stiffness matrix and film cell force vector,get whole equation。Finally design rotor-shaft system coupling scheme,rotor-shaft system coupling scheme is a strong nonlinear liquid-solid coupling patterns。Because rotor-shaft and bearing have similar equation,so use whole numerical method to couple,at the same time using alternative method to couple film equation。Simultaneous rotor-shaft and bearing equation to get whole equations system,put them with film equation resolve alternatively,then programme,will be able to calculate shaft axial trace,flexivity and bearing deforming。After using optimizing method,this machine′s five multiple base frequency and 1200Hz′s noise reduced obviously。Product performance fulfill customer′s demand。...