1bearings軸承

Twotypesofbearingsareusedtosupportashaft,i.e.slidingandrollingbearings.Withsmallfriction,highrotationflexibilityandeasytomaintain,rollingbearingsarewidelyusedstandardcomponentsofmechanicalequipment.

軸承分為滑動軸承和滾動軸承，用于支撐軸。滾動軸承的摩擦阻力小，轉動靈活，維修方便，是機械設備中廣泛應用的一種標準件。Structureofrollingbearings滾動軸承的結構Typesofrollingbearings滾動軸承的分類

LimitandFitofrollingbearings滾動軸承的極限與配合

55.Bearings滾動軸承請點擊相應標題顯示其內容5.1Structureofrollingbearings滾動軸承的結構1)InnerraceTightlymountedontheshaftandrotatingwithit.

內圈緊密套裝在軸上,隨軸旋轉；請點擊鼠標左鍵顯示后面內容Thestructureofrollingbearingsconsistsoffourcomponents滾動軸承的結構一般由四個元件組成:5.1Structureofrollingbearings滾動軸承的結構Outerrace外圈

Cage保持架Innerrace內圈Rollingelements滾動體2)OuterraceMountedonthebearing’sbracketholeandfastened.

外圈裝在軸承座的孔內,固定不動；3)RollingelementsLocatedbetweentheinnerandouterrings.Theyincludeballs,columns,andcones.

滾動體形式有圓球、圓柱、圓錐等,排列在內、外圈之間；4)Cage

Usedtoisolatetherollingelement.

保持架用來把滾動體隔開。根據滾動體的形狀劃分1.Typesofrollingbearings滾動軸承的分類

1.Typesofrollingbearings滾動軸承的分類

Radialbearingusedtobeartheradialload.Suchasdeepgrooveballbearings.

向心軸承主要用于承受徑向載荷，如深溝球軸承。1.Typesofrollingbearings滾動軸承的分類(2)Thrustbearing

itonlybearstheaxialload.Suchasthrustbearings.

推力軸承只承受軸向載荷，如推力球軸承。1.Typesofrollingbearings滾動軸承的分類(3)Radialthrustbearing

itbearsboththeradialandaxialloads.Suchasthetaperedrollerbearing.向心推力軸承能同時承受徑向載荷和軸向載荷,如圓錐滾子軸承。有關滾動軸承的國標規定：規定了滾動軸承本身的尺寸公差、旋轉精度（跳動公差等）、測量方法；還規定可與滾動軸承相配的箱體孔和軸頸的尺寸公差、形位公差和表面粗糙度。accordingtodimensionprecisionandrotationalprecisionrollingbearingincludefivegrade:滾動軸承的五種精度等級a.GB/T30794（國家標準）:B,C,D,EandG.b.ISO（國際標準）:class2,class4,class5,class6andNormalclass.c.JIS（日本工業部標準）:JIS2,JIS4,JIS5,JIS6andJIS0.d.DIN（德國工業部標準）:P2,P4,P5,P6andP0.3precisiongrade

Giscommongrade普通級

Eisseniorgrade

高級

Disprecisegrade精密級

C,Bissuperprecisegrade超精級4.Usingoftheprecisiongrade精度等級選用Ggradeisoftenusedincommonmachine,suchasmiddlerotationalspeed,precisionandloadmachine.

G級：普通級，適用于普通機床和汽車的變速機構；(2)E,D,C,Bgradeareoftenusedinhighprecision,rotationalspeedandloadmachine.Disoftenusedinfrontbearingofcommonmachinetool’saxle;D級：精密級，普通機床主軸的前軸承；

Eisoftenusedinbackbearingofcommonmachinetool’saxle;E級：高級，適用于普通機床主軸后軸承；

Cisoftenusedinbearingofprecisemachinetool;

C級適用于較精密機床主軸的軸承、儀器、儀表；

Bisoftenusedinbearingofsuperprecisemachinetool;B級適用于高速運轉特別精密機械，如數控機床。(3)ForEorGgraderollbearing

E、G級的滾動軸承

ShaftfromIT5toIT7軸的公差等級

holefromIT6toIT8殼體孔的公差等級(4)ForDandCgraderollbearingD、C級的滾動軸承ShaftfromIT4toIT5軸的公差等級

holefromIT5toIT6殼體孔的公差等級Fig.5.1Commonfitsofshaftandhousing5.2ISONomenclatureISO系統要求

公差帶與基準制？Thetolerancezoneofrollingbearing滾動軸承公差帶1）singledirection單向公差帶2）basicdeviationofinnerraceisES內圈基本偏差為ES3）basicdeviationofouterises外圈基本偏差為esGEDCBGEDCB+0-+0-Dd軸承外圈外徑的公差帶軸承內圈內徑的公差帶2.TheReferencesystemofrollingbearing基準制選擇(1)InnerraceandshaftisHole-basedsystemoffit;

內圈與軸配合基孔制(2)OuterraceandholeisShaft-basedsystemoffit.

外圈與軸承座配合基軸制Fig.5.1Commonfitsofshaftandhousing選擇軸承配合性質的依據？內外圈所受的負載類型、負載的大小、工作條件、相配合的孔和軸的材料和裝卸要求等。5.3VariousLoadConditions各種載荷情況1.Thetypeofload負荷類型（1）directload定向負荷或局部負荷（2）cyclingload循環負荷（3）swingload擺動負荷directload局部負荷——外圈相對于負荷方向固定Loosefittingcyclingload循環負荷——內圈相對于負荷旋轉Tightfittingswingload擺動負荷——大小和方向按一定規律變化的徑向負荷作用在套圈的部分滾道上。Table5.1LoadconditionsandfitsOuterrace——directloadInnerrace——cyclingloadthechoiceoffit

配合的選擇(1)directload:TransitionFitorClearanceFit(g,h)

局部(定向)負荷選過渡或間隙配合(g,h）(2)cyclingload:TransitionFitorInterferenceFit(Ymin)

循環負荷選擇過渡或較小過盈量的過盈配合(3)swingload:TransitionFit

擺動負荷選擇過渡配合2Theamountofload負荷大小

（1）P<0.07C,lightloadP<0.07C時為輕負荷（2）0.07C<P<0.15C,commonload

0.07C<P<0.15C時為正常負荷

（3）P>0.15C,weightload當P>0.15C時為重負荷5.4GeometricandDimensionalAccuracy,SurfaceFinishofrollingBearings滾動軸承的形位精度、尺寸與表面粗糙度Fig5.3geometricaltolerances例附表4.4、4.55.5TheDesignandSafetyGuidelines滾動軸承的安全精度設計與指導Thetolerancezoneofshaftandholefitted

與滾動軸承配合的軸和殼體孔的公差帶holeissixteentolerancezone:G7,H8,H7,H6,J7,JS7,J6,JS6,K6,K7,M6,M7,N6,N7,P6,P7;殼體孔的公差帶5.5TheDesignandSafetyGuidelines滾動軸承的安全精度設計與指導(2)shaftisseventeentolerancezone:g6,g5,h6,h5,j5,js6,k5,k6,m5,m6,n6,p6,r6,r7,h8,h9.軸的公差帶Φ100H7（）+0.0350A0.015A0.061.62+0.012Φ55j6（）-0.0070.040.01AA0.631.25（1）在零件圖上，應標注以下參數：A、尺寸公差B、形狀公差C、位置公差D、表面粗糙度2.Markingindetaildrawingsandassemblydrawings.零件圖和裝配圖的標注φ55j6φ100H7（2）在裝配圖上，不用標注軸承的公差等級代號，只需標注與之相配合的軸承座及軸頸的公差等級代號。Example:PrecisiongradeofRadialballbearingisE.Innerracerotatewithshaftandinnerracediameterd=50mm.OuterraceisstationaryandouterracediameterD=90mm.DirectionalloadP=4000N,ratedloadCr=31400N.例題：精度等級為E級的徑向球軸承，內圈隨軸旋轉，內圈直徑d=50mm，外圈靜止，外圈直徑D=90mm，定向負荷P=4000N，額定負荷Cr=31400N。Question問題：

1.Tolerancezonecodeofshaftandhousingfittedwithbearing?與滾動軸承配合的軸和殼體孔的公差帶代號？2.Geometricaltoleranceandsurfacefinishofshaftjournal?

軸頸的形位公差和表面粗糙度?3.Geometricaltoleranceandsurfacefinishofshaftshoulder?

軸肩的形位公差和表面粗糙度?4.Geometricaltoleranceandsurfacefinishofhousingjournal?殼體孔頸的形位公差和表面粗糙度?5.Geometricaltoleranceandsurfacefinishofhousingshoulder?殼體孔肩的形位公差和表面粗糙度?1.Tolerancezonecodeofshaftandhousingfittedwithbearing?與滾動軸承配合的軸和殼體孔的公差帶代號？Solution:P=0.127Cr正常負荷

table5.17ortable5.19

查附表4.2，4.3得軸公差帶代號k5,殼體孔公差帶代號H62.Geometricaltoleranceandsurfacefinishofshaftjournal?

軸頸的形位公差和表面粗糙度?Solution：table5.2or附表4.4得圓柱度2.5微米，表面粗糙度0.63微米；3.Geometricaltoleranceandsurfacefinishofshaftshoulder?

軸肩的形位公差和表面粗糙度?Solution:

附表4.4得端面圓跳動8微米，表面粗糙度1.25微米；4.Geometricaltoleranceandsurfacefinishofhousingjournal?殼體孔頸的形位公差和表面粗糙度?Solution：

圓柱度6微米，表面粗糙度1.6微米；5.Geometricaltoleranceandsurfacefinishofhousingshoulder?殼體孔肩的形位公差