长江大学机械原理习题集.pdf

Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 2 1Please draw the kinematic diagrams of the mechanisms shown below 1 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 2 2 Please calculate the DOF of mechanisms as follows can you point out these mechanisms have a determined motion or not The link with arrow is driving link 2 d c Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 3 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 3 1 Please confirm the location of the instant centres of mechanisms as follows Using the sign ij P 4 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 4 1 According to the link dimension determine the type of four bar linkage holding different link as frame 5 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 4 2 In a revolute four bar linkage ABCD shown as below b 100mm c 80mm d 110mm 1 Find the range of the values for the length LAB of link AB if the linkage is either a crank rocker mechanism with crank AB or b a double rocker mechanism 2 Can the linkage be a double crank mechanism by choosing LAB suitably Why 6 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 7 min 4 3 In the double crank linkage ABCD shown as below LAB 80mm LBC 180mm LCD 230mm LAD 200 The driver BC rotates at a constant speed Find the minimum transmission angle of the linkage Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 8 0 135 4 4 In the revolute four bar linkage ABCD Let link AD is the frame LAB 60mm LBC 130mm LCD 140mm LAD 200mm and BAD 1 Determine the type of the revolute four bar mechanism 2 If the side link AB is a driver and rotates at a constant speed a find the pressure angle and transmission angle of the mechanism at that position b Find the angular max stroke of the link CD c Find the crank acute angle between the two limiting positions d Calculate the time ratio K e Will any dead point occur during the whole cycle of the motion f Find the maximum pressure angle max and the minimum transmission angle min Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 4 5 Design the revolute four bar linkage ABCD according to the figure as below 9 0 45 Let the length of rocker LCD 75mm LAD 100mm and Link AD is the frame the time ratio K 1 5 The angle between one limiting position of rocker and the frame Calculate the length of LAB LBC has two results CDA Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 10 0 x 30 4 6 Design the offset slider crank mechanism ABC according to the figure as below The crank AB is the driver Let the length of crank LAB 25mm The offset e 10mm The maximum pressure angle ma Find the stroke H of the slider and the crank acute angle between the two limiting positions Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 11 mm754 7 图所示为一牛头刨床的主传动机构 已知lAB 行程速比系数K 2 刨头5的行程H 300mm 要 求在整个行程中 推动刨头5有较小的压力角 试设计此机构 mm100lDE Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 12 mm4 5 1 For the plate cam with translating offset knife edge follower Let the lifth 2 cam angle for rise cam angle for outer dwell cam angle for return cam angle for inner dwell The follower rise as constant acceleration and deceleration motion curve and return as cosine acceleration motion curve 0 120 0 60 0 60 0 s s 0 0 120 Please draw the displacement curve of the follower Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 5 2 For the plate cam with translating offset knife edge follower shown as below Please draw the displacement curve of the follower by graphical method 13 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 14 mm5 5 3 图示为一偏置滚子从动件盘形凸轮机构 已知凸轮轮廓由三段圆弧和 一 直 线 组 成 它 们 的 圆 心 分 别 O O 及 O 半 径 分 别 为 rmmrmmr36 18 及 mmrT5 偏 距e 8mm 滚 子 半 径 现要求 1 画出凸轮的理论轮廓曲线及基圆 2 求出从动件的行程 h 推程运动角 a 及回程运动角 c 3 标出图示位置从动件的位移及凸轮机构的压力角s 4 标出凸轮由图示位置转过 600时 从动件的位移 S 及凸轮机构的 压力角 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 15 mm30 6 1 For the figure shown as below Let the radius of base circle rb The radius of the involute at the point K mm15 k r KKmmrk35 Find 1 The radius of the involute at the point K and the pressure angle k k r 2 if k r Calculate the length of arcK K Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 16 0 20 6 2 An involute standard spur gear has parameters Z 26 m 3mm h a 1 Find the radii of curvature of tooth profile on the reference circle and the tip circle and the pressure angle on the tip circle Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 17 0 20 9 5 6 3 A pair of standard external spur involute gears has a module of 5mm pressure angle center distance a 350mm transmission ratio 12 i Calculate the numbers of teeth Z1 Z2 reference diameters d1 d2 addendum diameters da1 da2 base diameters db1 db2 tooth thickness s and spacewidth e Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 18 0 20 6 4 For a pair of external standard spur gears pressure angle module m 20mm Z1 30 Z2 40 1 Calculate the working pressure angle when the working center distance is a 725mm 2 If the working pressure angle 0 22 30 find the center distance is a Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 19 0 20 6 5 For a pair of external standard spur gears m 5mm Z1 19 Z2 42 Calculate the contact ratio Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 20 12 2 6 6 已知一对外啮合变位齿轮传动 1 ZZ m 10mm 试设计这对齿轮传动 列表给出两轮 的 并验算重合度及齿顶圆齿厚 Sa应大 于 0 25m 取 0 20 aha 1 dddhhy fafa 21 xx mm130 sdb Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 21 1 an h 6 7 A pair of standard external helical gears have the following parameters m 5mm Z1 20 Z2 118 B 30mm a 350mm 0 20 n Find the helix angle total contact ratio and the virtual numbers of teeth Zv1 Zv2 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 22 11 15 4 1Z 7 1 Shown in figure below The teeth numbers of some gears are given Z2 35 ZZ righthanded Z5 40 Z6 1 lefthanded Z7 28 5 Z 64 Find the teeth number of 2 Z Z3 Z4 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 23 22 7 2 shown in figure below It is a differential gear train with 1 15 ZZ25 Z20 3 60Z n1 200r min n3 50r min Find nH when 1 n1 and n3 are in the same direction 2 n1 and n3 are in the opposite direction Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 7 3 shown as figure below Every gear is standard gear and they have the same module The teeth numbers are given 14 1 Z 38 2 Z 24 70 3 Z Find the ratio H1 i Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 7 4 In the combined gear train shown in figure below 36 1 ZZ 60 2 Z 23 3 49 4 Z 69 4 Z 31 5 Z 131 6 Z n1 3549r min Find both the magnitude and the direction of 94 7 ZZ 36 8 Z 166 9 H n 25 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 7 5 In the combined gear train shown in figure below 15 ZZ 6 17 Z Z227 Z218 3 34 Z 4 51 Z Find the train ratio i16 26 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 7 6如图所示为一减速器 已知 26 1 Z 32 2 Z 18 1 Z 14 5 12 2 Z 27 24 34 4 Z ZZZ 试求 1 H i Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 7 7 现需设计一如图所示的 2K H 型行星减速器 要求的减速比 为 5 33 设行星轮数 k 4 并采用标准齿轮传动 试确定各轮的齿 数 28 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 29 8 1 某自动机床的工作台要求有六个工位 转台停歇时进行工艺动作 其中 最长的一个工序为 30 秒钟 现拟采用一槽轮机构来完成间歇转位工作 设 已知槽轮机构的中心距 L 300mm 圆销半径 r 25mm 槽轮齿顶厚 b 12 5mm 试绘出其机构简图 并计算槽轮机构主动轮的转速 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 8 2 下图所示为某牛头刨床工作台送进机构中的螺旋传动 丝杠 2 的导程为 6mm 要求设计一棘轮机构来驱动丝杠 实现工作台的间歇进给运动 而且 使每次送进量可在 0 2 1 2mm 之间作有级调整 共 6 级 又设棘轮机构由 一曲柄摇杆机构驱动 棘爪装在摇杆上 试绘出机构简图 并作必要的计 算和说明 30 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 31 mm558 3 在利用图示镗刀头镗一 的孔时 发现被镗孔的实际直 径为mm88 54 问镗刀头应如何调整方能获得所需的尺寸 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 10 1 The disk like rotor in fig below has unbalanced masses 1 10mkg 2 21 4mkg 3 36mkg at rotating radii 1 100 rmm 2 112 rmm 3 110rmm angular orientations Determine the magnitude mC and the location angle C 00 3 270 0 12 30 130 o the counterweight if it is to be placed at a rotating radii rC of 115 mm f 32 Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 33 kg10 10 2 On the non disk rigid rotor shown in fig below there exist four unbalanced masses Their masses rooting radii and angular locations are m1 kg15 kg20 kg10m2m3m4 cm40r1 cm30r4 r2 cm20r3 and 00 12 240 0 4 30 0 123 300 120 2334 30lllcm The system is to be balanced dynamically by adding a mass mA in the balancing plane A at a rotating radius rA of 50 mm and removing a mass mB on the balancing plane B at a rotating radius rB of 60mm Determine the magnitudes mA and mB and angular locations AB and of the required massed A B Exercise of mechanisms and machine theory Name class Order number Grade Name class Order number Grade 34 1223 40 11 1The train gear shown in fig below the teeth number are given ZZ20 ZZ 2 kg m 2 and moment of inertia of gears are given too The resistant momen