中国石油大(北京)机械原理考研习题Chapter.ppt

7-7. Shown below is a hoist. The teeth numbers of all the gears are: Z1=20, Z2=50, Z2’=15, Z3=30, Z3’=1, Z4=30, Z4’=18, Z5=52. Find the train ratio i15 and point out the rotating direction of the handle to raise the weight. 7-8. Shown below is the gear train in a clock. S, M and H denote the pointers of second, minute and hour, respectively. The given numbers of teeth are Z1=Z2’=8, Z2=64, Z3’=12, Z4’=15. If the modules of gear 4 and gear 5 are equal, find the numbers of teeth Z3, Z4, and Z5. 7-9. Shown below is a differential gear train with Z1=15, Z2=25, Z2’=20, Z3=60, n1=200 r/min, n3=50 r/min. Find both the magnitude and the direction of nH when (1)?n1 and n3 are in the same direction;(2) n1 and n3 are in the opposite directions. (1)?n1 and n3 are in the same direction (2)?n1 and n3 are in opposite directions 7-10. Shown below is a gear train in which gear 3 engages with gears 2 and 4 simultaneously. What kind of gear train is it? If Z1=34, Z2=Z3=20, and Z4=74, find the train ratio i1H. 7-11. Shown below is a gear train with Z1=16, Z2= Z2’ =25, Z3=57, Z4=56. Find the train ratio i14. The gears 1, 2, 3 and H make up a planetary gear train. The gears 3, 2(2’), 4 and H make up a planetary gear train. They are two planetary gear trains in series (串联). 2、 In planetary gear train 1-2-3-H 常见错误1： 常见错误2： When n1 and n3 are in the same direction， 常见错误3： When n1 and n3 are in the same direction， 常见错误4： When n1 and n3 are in the opposite direction， 7-12. In the combined gear train shown below, Z1=36, Z2=60, Z3=23, Z4=49, Z4’=69, Z5=31, Z6=131, Z7=94, Z8=36, Z9=167, n1=3549 r/min. Find both the magnitude and the direction of nH. 7-13. In the combined gear train shown below, Z1= Z5= Z6=17, Z2=18, Z2’=27, Z3=34, Z4=51. n1=110 r/min. Find both the magnitude and the direction of n6. The gears 1, 2(2), 3 and 6 make up a differential gear train. 用行星轮系去约束差动轮系。 7-14. Shown in Fig.7-24 is a differe