机械设计、机械原理滚动轴承习题.ppt

1.一水泵选用深沟球轴承，已知轴颈d=35mm，转速n=2900r/min，轴承所受的径向力Fr=2300(N)，轴向力Fa=540(N)，要求使用寿命L10h=5000h，试选择轴承型号解：1)先求出当量动载荷P根据表13-5暂取Fa/Cor =0.025 e=0.22故用试算法因 Fa/Fr=540/2300=0.235＞e x=0.56 y=2.0因为轴承型号未选出前暂不知道额定静载荷Cor例题1选轴承型号Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.P=fd(XFr+YFa)=1.1×(0.56×2300+2.0×540)=2605(N) 查表13-6 fd =1.12) 求所需的基本额定动载荷3) 选轴承型号 查手册 6307轴承 Cr=33.4(KN) Cor=19.2(KN) 6207轴承 Cr=25.5(KN) Cor=15.2(KN)例题1Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd. 6307轴承 Fa/Cor=540/19200=0.0281与原假设e=0.028相近例题16207轴承Fa/Cor=540/15200=0.0355与原假设e=0.028 相远 所以 取6307轴承。

Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd. 7206C滚动轴承组合结构形式如图示，已知：FA=600N Fr1=1970N Fr2=1030N fd=1.1 n=1000r/min试分析轴承Ⅰ、Ⅱ所受的轴向力Fa及当量动载荷P，并说明哪个轴承是危险轴承解：采用一对 7206C 轴承反装Cr=23000(N)，Cor=15000(N)根据表13-7 7000型轴承Fd=eFr轴承例题2Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.1) 试算法 取判断系数e e=0.43 根据表13-52) 求附加轴向力 Fs1=0.43×Fr1=0.43×1970=847(N) Fs2=0.43×Fr2=0.43×1030=443(N)3) 求轴承的轴向力 FA+Fs1=600+847=1447＞Fs2=443轴承例题Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Ⅱ轴承压紧，Ⅰ轴承放松Fa1=FS1=847(N) Fa2=FA+FS1=1447(N)4) 求当量动载荷轴承Ⅰ查表13-5 与前面假设e=0.058相近。

e插入求值轴承例题Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.X1=0.44 PⅠ=fd(0.44Fr1+1.306Fa1) =1.1 (0.441970+1.306847)=2170(N)轴承Ⅱ取X2=0.44轴承例题Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.P2=fd(X2Fr2+Y2Fa2)=1.1(0.441030+1.2181447)=2437(N)P2＞P1 ∴轴承Ⅱ危险轴承例题Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.。