阻尼弹簧隔振器选用要点和安装方法

Selecting methods of damp spring vibration absorber and installation

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一、隔振器的静载荷与高度分四种类型

1、零静载荷：隔振器处于自由状态，不承受任何负载，称为零载荷。此时隔振器的高度H为弹簧自由高度、上下盖及防滑胶垫厚度之和。

2、顶压静载荷：隔振器通过预压螺栓施加力于弹簧，使弹簧压缩到一定高度，预压螺栓施加的力称为预压载荷，一般情况下隔振器出厂时即为这一状态。预压载荷下隔振器的高度称为预压高度，记为H，，则H1=H-F1／K cm 式中，F1-预压载荷NK一隔振器静刚度N／cm

3、工作静载荷：隔振器工作时所承受的实际载荷，此时隔振器的高度记为H，则 H2=H0-F2／K=H1-(F2-F1)／K cm 式中，F，一工作静载荷N 在具体设计时，隔振器工作时实际高度H2可按上式计算。

4、最大静载荷：出于对强度及使用寿命等角度考虑，隔振器在使用时所允许承受的最大载荷。此时隔振器的高度为H3，则 H3=H0-F3／K cm 式中，F3一隔振器所能允许承受的最大载荷，在选用隔振器时，工作载荷可选择在预压载荷F1和最大载荷F3之间，一般以宜选在中间值为好，中间值记F，，则F2=(F3-F，)／2+F1N

二、隔振效率的简易计算

1、根据振动控制的有关标准确定隔振效率g

2、忽略阻尼，则有振动传递率T=1／[卜(f／f0)2]- 隔振效率11=(1 T)％于是由g可以确定f／f0的大小，即频率比。式中，f---扰力频率Hz fo---隔振系统固有频率Hz 当考虑阻尼时，隔振效率略有下降，计算公式及图表如下：

A、DMdeintofourtypes accordingtothe staticload andheight

1、Zero staticload :111e stateinwhicbthevibrationabsorberisfree and has no load on is called zero static load．Herethetotal heightHOfthe vibration absorberincludingtheheight offree spring,topbase cover,endrubber skidproofmat．

2、Toppressure staticload :The vibration absorber exerts aforce on the spring by the preliminary press bolt，then the spg is compressed to some extent．Heretheforceis calledasF．preliminarypressloadN Normally the vibration absorber is in this stateasit is producted Here the height H1 is called aspreliminary pressheight,then H=IInFI／K cm HereKstatic idnyofvibrationabsorber

3、Working staticload:Working static load is the actual load matthevibration ahsorber cen bear when it is worldng，Here the height of vibration absorber is H2 H=H0一F2／K=H。(E—F。)／K cm Andin the formula．F2working smileloadN．The actual height Hofworking vibration absorber can be calculated according to the for mulamentioned above when it is carefully designed．

4、 Maximum staticloade permitted maxnmlm load that the vibration absorber can bear when it is working inview of intensity,using life end so on． Here the height of evibration absorberis H3．end H3=H—F3／K cm here，F3permittedmaimload，The magnitude ofworking 10ad can beany value between preliminary load F1 end maxlmlma load F3 Commonly the best choice is the middle value which is wri~enas F2 F2=(F3 F。)/2+F。N

B、Simple calculation of isolating vibration efficiency

1、Ascertain the isolating vibration efficiency n according to corresponding standard of vibration control．

2、Neglect damp，vibration transfer efficiency appears． T=1，[1-f/f0)2] Isolating vibration efficiency n=(1—T)

SothevalueofF／F0whichisfrequency ratio canbe confirmed by n，here~sturb frequency Hz fdutrinsicfre~ency ofthe system Hz Reckon in damp，isolating vibrailon efficiency descends shghfly, formulaandfigure showasfollows：

3、频率计算

A、扰力频率：对于旋转设备，扰力频率f一般为f=n／60 Hz 式中，n一机器每分钟转速r／min

B、隔振系统固有频率f0对于弹簧隔振器f。的计算方法有以下简易方法： fo=5／、厂_矿Hz 6=F2／K cm 式中，6一隔振器工作时，弹簧压缩量cm K---隔振器静刚度N／cm F，隔振器工作时承受的静载荷N

三、隔振器的选取

根据以上计算，选取隔振器遵守两个原则：

1、隔振器工作时承受的静载荷在预压载荷和最大载荷之间即可，宜选在中间值附近。如被隔振机器设备扰力很大或为冲击设备，则工作载荷选取点不要离最大载荷太近。

2、隔振器的固有频率选择可根据二提供的方法计算。一般情况下，应选择频率比f／f0=2．5～4．5，此时隔振效率在80％~95％。

3、阻尼比选择原则为：

1、对旋转设备和旋转往复设备，视转速高低，阻尼比可在0.03～0.10范围选取，阻尼比不宜大于0．1 5。

2、对锻冲设备，阻尼比应在0．1 5～ 0．30范围内选取。

3、Frequency calculation

a．disturbfrequency：0013~1valueisF---n／60Hz，forrevolving inslrtmaents．herennlpmofequipment．

b intrinsicfrequencyofisolatingvibrailon systems' ordinary calculate method of'shows as follows， fF5/6 Hz 6=FJKem here 6 compressed magnitude of spring when working ern KstaticrigofthevibrationabsorberN／cm F2staticloadwhenworkingN

C、Selecting method

Obey two rulaswhen selectingvibrationabsorberaccordingto the calculation as mentioned above：

1、memagnitude of staticload can been any valuebetween pretimimz~10adFlendmaxmmmloadf but it is appro priate to be nearthemiddle value．Iftheisolatedin stmment acutely disturbs or is a kind ofimpulsive equipment，the value of workingload shouldbe selectedfarfromthemaximumload．

2、The calculationoftcan followsthemethodtwomentioned abOVC，Undernormalcondition，frequcucy ratioisf／f_2．5～4．5，here isolating vibration efficiency is about 80％~95％．

3、Selecting rulesofdamp ratio

1)T damp ratio is 0．03 NO．10 according to the speed of rotationforthe revolvinginstrumentor rectprotator,anditisnot sultableto exceed0．15

2)The damp railo is 0，15～O．30 for forging and pressing equipments．

安装方法

一、一般情况下，隔振器底座与基础之间不必用地脚螺栓连接。

二、隔振器上部与机器设备底座或隔振台座之间是否采用螺栓连接，可视具体情况确定。

1、当设备扰力不大时，则隔振器上部不必与设备固定。

2、当动力设备扰力较大时，四个角的隔振器可与设备底座或隔振台座固定，而中间几个隔振器不固定，以便移动其位置，达到所有隔振器静态压缩量相同之目的。

Installation

A、Undernormal condition．thefoot connectingboltneednottobeusedbetweenthebaseOf vibrationabsorber andthe groundworkofequlpmem

B、Top coverof vibrationabsorber can befixedwithconnectingbolt either on thebaseof equipment or onthefibmfioninsulatingdado accordingtothe real situation

Top coverneed notbefixedontheequlpmeutwhilethe dlstorbingforce ofthe power equipmentistiny．

2、Whisth ethedlstorbingforce ofthepower equipmentisquietgreat．the vibration absorber Ollthefour cornels Callbefixed eitheronthebase 0fequipmentoronthevibrationinsulating dado．Othervibration absorbersinthemiddle shouldnotbefixe so they canbe removedin ordertoreachthe aimthat allthe smile compressedvalue ofthevibrationabserber are$aole