例2.已知:Za=100、zb=99、Z=101、 圆心 Z4=100求:ltm 解:im Ha =10000 0.25% 若为定轴轮系 ∴=0.9999 =1.0001 b 若Z=99则ia b c d H 例 2. 已知: Za = 100、Zb = 99、 Zc = 101、 Zd = 100 求: iHa 解: 若为定轴轮系 若 Za = 99 则 iHa =  = -100 ● i Ha = = b Ha i H ab 1− i 1 10000 1 ( ) 1 = =   − =  a c c b z z z z = = 0.9999   =  a d c b ab z z z z i 1.0001 1 = == ab ba i i η= 0.25% a b c d