技术官员村位于位于亚运城东部,主干道二以东石楼涌以西的地块,占地面积、m2,总建筑面积、m2,共包括地下室南区、地下室北区、地上部分1栋~12栋、服务中心、室外工程等多个单体工程。其中住宅面积m2,共12栋,1~7栋建筑层数为11层,8~12栋11层(局部复式顶层),首层局部架空,布置公建配套设施。integratedenergy,chemicalsandtextileYibincity,arethethreecorepillarsoftheindustry.In2014,thewuliangyebrandvalueto73.58billionyuan,thecity'sliquorindustrysliptostabilise.Promotingdeepdevelopmentofintegratedenergy,advancedequipmentmanufacturingindustry,changningdistrict,shalegasproductioncapacityreached277millioncubicmetres,builtthecountry'sfirstindependenthigh-yieldwellsandpipelinesinthefirstsection,theleadinfactoryproductionandsupplytothepopulation.2.1-3GDPgrowthfigure2.1-4Yibin,Yibincity,Yibincity,fiscalrevenuegrowth2.1.4topographyterrainoverallisSouthwest,North-EasternState.Lowmountainsandhillsinthecitylandscapeasthemainridge-and-Valley,pingbasmallfragmentednaturepictureforwaterandthesecondlandofthesevenhills.236metersto2000metersabovesealevelinthecity,lowmountain,46.6%hills45.3%,pingbaonly8.1%.2.1.5developmentofYibinlandscapesanddistinctivefeatureinthecenterofthecity,withlimitations,andspatialstructureoftypicalzonalgroup,2012-citiesinbuildingwithanareaofabout76.2km2.Fromcity-buildingsituation,oldtown-theSouthBankCenterconstructionislaggingbehind,disintegrationoftheoldcityisslow,optimizationandupgrading,qualitypublicserviceresourcesarestillheavilyconcentratedintheoldtowntogether.SouthbankCentrehasnotbeenformed,functionsoftheserviceareaspaceismissing.Meanwhile,peripheralgroupcentresservicewasweakandinadequateaccountingforcitydevelopment,suspiciouspatterncouldnotbeformed.Asregardstransport,withtheoutwardexpansionofcities,citieshavebeenexpanding,centripetalcitytrafficorganizationhasnotchanged,integratedenergy,chemicalsandtextileYibincity,arethethreecorepillarsoftheindustry.In2014,thewuliangyebrandvalueto73.58billionyuan,thecity'sliquorindustrysliptostabilise.Promotingdeepdevelopmentofintegratedenergy,advancedequipmentmanufacturingindustry,changningdistrict,shalegasproductioncapacityreached277millioncubicmetres,builtthecountry'sfirstindependenthigh-yieldwellsandpipelinesinthefirstsection,theleadinfactoryproductionandsupplytothepopulation.2.1-3GDPgrowthfigure2.1-4Yibin,Yibincity,Yibincity,fiscalrevenuegrowth2.1.4topographyterrainoverallisSouthwest,North-EasternState.Lowmountainsandhillsinthecitylandscapeasthemainridge-and-Valley,pingbasmallfragmentednaturepictureforwaterandthesecondlandofthesevenhills.236metersto2000metersabovesealevelinthecity,lowmountain,46.6%hills45.3%,pingbaonly8.1%.2.1.5developmentofYibinlandscapesanddistinctivefeatureinthecenterofthecity,withlimitations,andspatialstructureoftypicalzonalgroup,2012-citiesinbuildingwithanareaofabout76.2km2.Fromcity-buildingsituation,oldtown-theSouthBankCenterconstructionislaggingbehind,disintegrationoftheoldcityisslow,optimizationandupgrading,qualitypublicserviceresourcesarestillheavilyconcentratedintheoldtowntogether.SouthbankCentrehasnotbeenformed,functionsoftheserviceareaspaceismissing.Meanwhile,peripheralgroupcentresservicewasweakandinadequateaccountingforcitydevelopment,suspiciouspatterncouldnotbeformed.Asregardstransport,withtheoutwardexpansionofcities,citieshavebeenexpanding,centripetalcitytrafficorganizationhasnotchanged,二.习题(一)思考题1.渐开线具有哪些特性?答:(1)发生线沿基圆滚过的长度,等于基圆上被滚过的弧长;(2)因为发生线BK沿基圆作纯滚动,所以它和基圆的切点B就是它的速度瞬心,因此发生线BK即为渐开线在K点的法线。又因为发生线恒切于基圆,故可知,渐开线上任意点的法线恒为基圆的切线。(3)发生线与基圆的切点B也是渐开线在K点的曲率中心,线段BK是渐开线在K点的曲率半径。因此,渐开线越接近其基圆的部分,其曲率半径越小。(4)同一基圆上任意两条渐开线(不论是同向或反向)的公法线处处相等。(5)基圆内无渐开线。(6)渐开线的形状取决于基圆的大小。2.何谓标准齿轮?何谓标准中心距?一对标准齿轮的实际中心距a′略大于标准中心距a时,其传动比有无变化?仍能继续正确啮合吗?其顶隙、齿侧间隙和重合度有何变化?答:(1)通常所说的标准齿轮是指m、α、h*a、c*都为标准值,而且e=s的齿轮。即模数、压力角、齿顶高和齿根高均为标准值,且分度圆上齿厚与齿槽宽相等的齿轮称为标准齿轮。(2)①保证啮合时两轮的顶隙为标准值;②标准齿轮分度圆的齿厚s等于齿槽宽e,有s1=e1;s2=e2,即s1=e2;s2=e1,即一对齿轮在保证顶隙为标准值时也保证齿侧间隙为零。将满足上述两个条件的安装中心距称为标准安装中心距(简称标准中心距),用a表示。(3)传动比没有变化。仍能正确啮合。顶隙、齿侧间隙增大,重合度减小。3.何谓齿廓的根切现象?齿廓的根切有什么危害?在什么情况下会产生根切现象?根切与何因素有关?如何避免根切?答:(1)用范成法加工渐开线齿轮时,在一定的条件下,齿条刀具的顶部会切入被加工齿轮轮齿的根部,将齿根部分的渐开线切去一部分,这种现象称为渐开线齿廓的根切。(2)根切使得轮齿的弯曲强度和重合度都降低了,对齿轮的传动质量有较大的影响,所以根切是应该避免的。(3)如果刀具的齿顶高增大,齿顶线超过啮合极限点N,则刀具将轮齿基圆外的渐开线已全部切出时,整个切削过程并未结束,随着范成运动的继续,刀具还将继续切削,使刀刃将已经切制好的一部分渐开线齿廓又切去了,从而产生根切。(4)①采用标准齿轮,保证minzz;②采用变位齿轮。技术官员村位于位于亚运城东部,主干道二以东石楼涌以西的地块,占地面积、m2,总建筑面积、m2,共包括地下室南区、地下室北区、地上部分1栋~12栋、服务中心、室外工程等多个单体工程。其中住宅面积m2,共12栋,1~7栋建筑层数为11层,8~12栋11层(局部复式顶层),首层局部架空,布置公建配套设施。integratedenergy,chemicalsandtextileYibincity,arethethreecorepillarsoftheindustry.In2014,thewuliangyebrandvalueto73.58billionyuan,thecity'sliquorindustrysliptostabilise.Promotingdeepdevelopmentofintegratedenergy,advancedequipmentmanufacturingindustry,changningdistrict,shalegasproductioncapacityreached277millioncubicmetres,builtthecountry'sfirstindependenthigh-yieldwellsandpipelinesinthefirstsection,theleadinfactoryproductionandsupplytothepopulation.2.1-3GDPgrowthfigure2.1-4Yibin,Yibincity,Yibincity,fiscalrevenuegrowth2.1.4topographyterrainoverallisSouthwest,North-EasternState.Lowmountainsandhillsinthecitylandscapeasthemainridge-and-Valley,pingbasmallfragmentednaturepictureforwaterandthesecondlandofthesevenhills.236metersto2000metersabovesealeveli