2022年机械原理习题机械的平衡donghuadaxue.docx

精选学习资料 - - - - - - - - - 机械原理网络课件机械的平稳 > 习题答案概念题1、机械平稳的目的？参考2、什么叫静平稳？参考什么叫动平稳？参考各需几个平稳基面？静平稳只需一个平稳面 , 而动平稳就需要两个平稳面 . 所以静平稳又叫 Single-plane balance, 而动平稳又叫 two-plan balance.3、刚性转子静平稳的力学条件是 不平稳惯性力的矢量和为零；动平稳的力学条件是 1 其惯性力的矢量和等于零,即P=0；2 其惯性力矩的矢量和也等于零,即M=04、图 1 所示的两个转子,已知m1r 1=m2r 2, 转子 a 是 静 不平稳的；转子b 是 动 不平稳的；图 1 5 、图 2a 、b 、c 中, s 为总质心,图a,b 中的转子具有静不平稳；图 c 中的转子具有动不平稳；运算题名师归纳总结 - - - - - - -第 1 页,共 4 页精选学习资料 - - - - - - - - - 1、如下列图曲轴上,四个曲拐位于同一平面内,如质径积m1r 1=m2r 2=m3r 3=m4r 4,l 1=l 2=l 3, 试判定该曲轴是否符合动平稳条件？为什么？该曲轴符合动平稳条件2、高速水泵的凸轮轴系由三个相互错开 120o 的偏心轮组成,每一偏心轮的质量为 m,其偏心距为 r, 设在平稳平面 A和 B上个装一个平稳质量 mA 和 mB, 其回转半径为2r, 其他尺寸如下列图；试求mA和 mB 的大小和方位（可用图解法）；题 2名师归纳总结 3、如下列图为一钢质圆盘；盘厚 =20mm,在向径r1=100mm处有始终径d=50mm的第 2 页,共 4 页通孔,向径r2=200mm处有一重量为2N 的重块,为使圆盘满意静平稳条件,拟在向径r=200 的圆周上再钻一通孔,试求次通孔的直径和方位（钢的重度 =7.6 × 10-5N/mm 3 ；- - - - - - -精选学习资料 - - - - - - - - - 题 34. A system of two coplanar 同一平面 arms on a common shaft, as shown in the right figure is to be designed. For the rows assigned in Table 1, find the shaking force of the linkage when run unbalanced at 10rad/sec and design a counterweight to statically balance the system.ambr b=0.934b=-75.5 ocmbr b=5.932b=152.3 oembr b=7.448b=-80.76 o5. A wheel and tire assembly has been run at 100 rpm on a dynamic balancing machine as shown in the following figure. The force measured at the left bearing had a peak of 5 lb at a phase angle of 45o with respect to the zero reference angle on the tire. The force measured at the right 名师归纳总结 bearing had a peak of 2 lb at a phase angle of -120o with respect to the 第 3 页,共 4 页- - - - - - -精选学习资料 - - - - - - - - - reference zero on the tire. The center distance between the two bearings on the machine is 10 in. The wheel is 7 in wide at the rim. Calculate the size and location with respect to the tire's zero reference angle, of balance weights needed on each side of the rim to dynamically balance the assemblyThe whell rim diameter is 15 in.Answer: 名师归纳总结 Wa=3.56lb a=44.44 o第 4 页,共 4 页Wb=2.13lb b=-129.4 o- - - - - - -