作业一第十三章滚动轴承习题解答:13-4.一农用水泵,决定选用深沟球轴承,轴颈直径d=35mm,转速n=2900r/min,已知径向载荷Fr=1810N,轴向载荷Fa=740N,预期计算寿命Lh’=6000h,试选择轴承的型号。解:若选用6207轴承,查《手册》,得:额定静载荷C0r=15.2kN;额定动载荷Cr=25.5kN715.0152107407.14CFfr0a02615.0ee41.01810740FFra698.1Y,56.0X故当量动载荷:N2497)740698.1181056.0(1.1)YFXF(fParp作业一第十三章滚动轴承5.25kN331.25N253312497106000290060P10'nL60C636hr计所需轴承额定动载荷:故6207轴承满足要求。作业一第十三章滚动轴承13-5.根据工作条件,决定在轴的两端选用α=250的两个角接触球轴承,正装。轴颈直径d=35mm,工作中有中等冲击,转速n=1800r/min,已知两轴承的径向载荷分别为Fr1=3390N,Fr2=1040N,外加轴向载荷Fae=870N,作用方向指向轴承1,试确定其工作寿命。解:若选用7207AC轴承,查《手册》,得:额定动载荷Cr=29.0kN派生轴向力N2.2305339068.0F68.0F1r1dN2.707104068.0F68.0F2r2dFd121Fd2Fae1dae2dFN2.15778702.707FF2紧1松2Fd2作业一第十三章滚动轴承0Y,1X11轴向力N2.2305FF1d1aN508533905.1)FYFX(fP1a11r1p1N2.1435FFFae1d2ae68.033902.2305FF1r1ae38.110402.1435FF2r2a87.0Y,41.0X22N5.2512)2.230587.0104041.0(5.1)FYFX(fP2a22r2p2取P=5085N轴承寿命h1717)085.50.29(18006010)PC(n6010L366h(7307AC:Lh=2485h;7407AC:Lh=10966h)作业一第十三章滚动轴承13-7.某轴的一端支点上原采用6210轴承,其工作可靠度为90%,现需将该支点轴承在寿命不降低的条件下将工作可靠度提高到99%,试确定可能用来替换的轴承型号。解:可靠度为99%时,轴承的寿命6210轴承额定动载荷为35.0kN101011L21.0LaL)PC(n6010L610原原)PC(n601021.0L21.0L6101新新新新原110LL)PC(21.0)PC(新原原新C21.01CkN87.580.3521.01C3新选用6310轴承,其额定动载荷为61.8kN