09年安徽农业大学机械考研试题及答案
安徽农业大学农业机械化硕士入学考试参考题
名词解释1. 播种机清种装置对于点（穴）播排种器，种子充入型孔时可能附带多余的种子而必须加以清除，以保证精量播种。
2. 传统耕作法也称精细耕作法，通常指作物生产过程中由机械耕翻、粑压和中耕等组成的土壤耕作体系。
3.分插机构用以完成分秧和插秧的工作部件称为秧爪（或称为分离针），而控制秧爪运动轨迹的机构称为分插机构。
4.分段收获收割机将作物切割后在田间铺放或捆束，在田间或运至脱粒场地用脱粒机脱粒。
5.分离装置将从脱粒装置排出的秸秆中夹带的谷粒及断穗分离出来，并将秸秆送往机后。
6.横向送秧机构是使秧爪能在秧箱的工作幅宽内依次均匀取秧，使秧箱连同秧苗做整地移动，又称为移箱器，它由螺旋凸轮轴、指销、指销座、移箱轴的配合来控制移箱距离、行程及移箱次数。
7.离心式喷头将药液输送到高速旋转的雾化元件上，在离心力的作用下，将药液从雾化元件的外边缘抛射出去，雾化成细小的雾滴，一般雾滴直径为15~75μm，故也称超低量喷头。
8.联合收获法一次完成收割、脱粒、分离秸秆、清选谷粒、装袋或随车卸粮各项工作。
9.免耕是免除土壤耕作，利用免耕播种机在作物残茬地表直接进行播种，或对作物秸秆和残茬进行处理后直接播种的一种耕作方法。
10.少耕通常指在常规耕作基础上减少土壤耕作次数和强度的一种保护性土壤耕作体系。
11.喷灌将具有一定压力的水喷射到空中，形成细小的水滴，洒落到地面和植物上的一种灌水方法。
12. 牵引犁牵引犁与拖拉机间单点挂接，拖拉机的挂接装置对犁只起牵引作用，在工作或运输时，其重量均由本身具有的轮子承受。
牵引犁由牵引杆、犁架、犁体、机械或液压升降机构、调节机构、行走轮、安全装置等部件组成。
耕地时，借助机械或液压机构来控制地轮相对犁体的高度，从而达到控制耕深及水平的目的。
牵引犁结构较先进，作业时无需农具手，但地头转弯半径大、机动性差。
13. 切土节距沿旋耕机的前进方向纵垂面内相邻两把旋刀切下的土壤厚度，即在同一纵垂面内相邻两把刀相继切土的时间间隔内旋耕机前进的距离。
机械设计试卷A-参考答案与评分标准
合肥学院20 09至20 10学年 第 1 学期机械设计 课程考试（A ）卷机械工程系 系 07 级 机械设计制造及自动化 专业 学号 姓名一、选择题（每题1分，共计20分）：1. 在进行疲劳强度计算时，其极限应力材料的____ B______。
A. 屈服极限B. 疲劳极限C. 强度极限D. 弹性极限。
2. 设计螺栓组联接时，虽然每个螺栓的受力不一定相等，但对该组螺栓仍均采用相同的材料，直径和长度，这主要是为了_ __C_ __。
A. 外形美观B. 购买方便C. 便于加工和安装3. 键的剖面尺寸通常是根据___ D_ __，按标准选择。
A. 传递转矩的大小B. 传递功率的大小C. 轮毂的长度D. 轴的直径4. 带传动中，在预紧力相同的条件下，V 带比平带能传递较大的功率，是因为V 带_____C______。
A. 强度高 B. 尺寸小 C. 有楔形增压作用5. V 带传动设计中，限制小带轮的最小直径主要是为了____ B______。
A. 使结构紧凑B. 限制弯曲应力C. 保证带和带轮接触面间有足够摩擦力D. 限制小带轮上的包角 6. 带传动采用张紧装置的目的是_ __D_______。
A. 减轻带的弹性滑动B. 提高带的寿命C. 改变带的运动方向D. 调节带的预紧力 7. 设计链传动时，链节数最好取___ A _____。
A. 偶数B. 奇数C. 链轮齿数的整数倍8. 链传动设计中，当载荷大、中心距小、传动比大时，宜选用___B_____。
A. 大节距单排链B. 小节距多排链C. 小节距单排链D. 大节距多排链装订线9.6206型号滚动轴承的内径d应该是____B_____mm。
A. 06B. 30C. 12D. 1010.球轴承和滚子轴承的支承刚性比较，__ C_____。
A. 两类轴承基本相同B. 球轴承较高C. 滚子轴承较高11.滚动轴承的额定寿命是指同一批轴承中__ __C______的轴承所能达到的寿命。
安徽农业大学农业机械化硕士入学考试参考题
安徽农业大学农业机械化硕士入学考试参考题名词解释1. 播种机清种装置对于点（穴）播排种器，种子充入型孔时可能附带多余的种子而必须加以清除，以保证精量播种。
2. 传统耕作法也称精细耕作法，通常指作物生产过程中由机械耕翻、粑压和中耕等组成的土壤耕作体系。
3.分插机构用以完成分秧和插秧的工作部件称为秧爪（或称为分离针），而控制秧爪运动轨迹的机构称为分插机构。
4.分段收获收割机将作物切割后在田间铺放或捆束，在田间或运至脱粒场地用脱粒机脱粒。
5.分离装置将从脱粒装置排出的秸秆中夹带的谷粒及断穗分离出来，并将秸秆送往机后。
6.横向送秧机构是使秧爪能在秧箱的工作幅宽内依次均匀取秧，使秧箱连同秧苗做整地移动，又称为移箱器，它由螺旋凸轮轴、指销、指销座、移箱轴的配合来控制移箱距离、行程及移箱次数。
7.离心式喷头将药液输送到高速旋转的雾化元件上，在离心力的作用下，将药液从雾化元件的外边缘抛射出去，雾化成细小的雾滴，一般雾滴直径为15~75μm，故也称超低量喷头。
8.联合收获法一次完成收割、脱粒、分离秸秆、清选谷粒、装袋或随车卸粮各项工作。
9.免耕是免除土壤耕作，利用免耕播种机在作物残茬地表直接进行播种，或对作物秸秆和残茬进行处理后直接播种的一种耕作方法。
10.少耕通常指在常规耕作基础上减少土壤耕作次数和强度的一种保护性土壤耕作体系。
11.喷灌将具有一定压力的水喷射到空中，形成细小的水滴，洒落到地面和植物上的一种灌水方法。
12. 牵引犁牵引犁与拖拉机间单点挂接，拖拉机的挂接装置对犁只起牵引作用，在工作或运输时，其重量均由本身具有的轮子承受。
牵引犁由牵引杆、犁架、犁体、机械或液压升降机构、调节机构、行走轮、安全装置等部件组成。
耕地时，借助机械或液压机构来控制地轮相对犁体的高度，从而达到控制耕深及水平的目的。
牵引犁结构较先进，作业时无需农具手，但地头转弯半径大、机动性差。
13. 切土节距沿旋耕机的前进方向纵垂面内相邻两把旋刀切下的土壤厚度，即在同一纵垂面内相邻两把刀相继切土的时间间隔内旋耕机前进的距离。
2009年同等学力申硕机械工程真题
2009年同等学力申硕机械工程真题(总分：260.00，做题时间：180分钟)一、考生须知 (总题数：1，分数：0.00)二、第一部分必考题（两组，共60 分） (总题数：4，分数：8.00)1.方块图包含了与系统 1有关的信息，与系统的 2无关。
（分数：2.00）填空项1:__________________ （正确答案：动态性能）填空项1:__________________ （正确答案：物理结构）解析：2.传递函数反映系统本身的 1特性，它只与系统本身的 2有关，与 3无关。
（分数：3.00）填空项1:__________________ （正确答案：动）填空项1:__________________ （正确答案：参数）填空项1:__________________ （正确答案：外界输入）解析：3.顺馈校正的特点是在干扰引起 1之前就对它进行 2补偿。
（分数：2.00）填空项1:__________________ （正确答案：误差）填空项1:__________________ （正确答案：近似）解析：4.在控制系统中，当输入信号与 1不相等时，比较装置就会出现误差信号。
（分数：1.00）填空项1:__________________ （正确答案：反馈信号）解析：三、简答题（本大题共4 小题，每小题3 分，共12 分）(总题数：4，分数：12.00)5.简述求传递函数的一般步骤。
（分数：3.00）__________________________________________________________________________________________ 正确答案：(①确定系统的输入和输出；②列出微分方程；③初始条件为零，对各微分方程取拉氏变换；④求系统的传递函数。
)解析：6.何谓线性系统？其最重要特性是什么？（分数：3.00）__________________________________________________________________________________________ 正确答案：(若系统的数学模型表达式是线性的，则这种系统就是线性系统。
2009级机械设计基础(A)答案
课程编号：03000138北京理工大学2010～2011学年第2期2009级机械设计基础期末试题A卷班级学号姓名成绩注：试卷共6页，试题解答一律作在试卷上，其它地方无效。
一、选择题（本题12分，每小题2分，把正确的代号填入括号中）1. 为提高闭式齿轮传动齿面接触疲劳强度，下面不正确的措施为（ D ）。
A 选择合金钢齿轮材料以提高许用应力B 加大中心距C 保证齿面加工精度基础上适当增加齿宽D 提高表面粗糙度2. 某二级斜齿轮减速器中间轴上两斜齿轮螺旋角之间关系，比较合理的设计是（B）。
A 旋向相反，大小相等B 旋向相同，大小不一定相等C 旋向相同，大小相等D 旋向相反，大小不一定相等3. 既能实现轴上零件轴向固定又能实现周向固定的措施为（ A ）。
A 销连接B 平键连接C 弹性档圈D 圆螺母4. 以下措施中，( C )可以提高受轴向变载荷的紧螺栓连接中的螺栓强度。
A 螺纹防松B 在被连接件间加橡胶垫片C 采用空心螺栓D 采用精制螺栓5. 带传动中带和带轮间摩擦系数与初拉力一定时，( B )则最大有效圆周力也愈大。
A 带轮宽度越大B 小带轮上的包角愈大C 大带轮上的包角愈大D 带速愈低6. 推力球轴承不适用于高转速，这是因为高速时( C )从而使轴承寿命严重下降。
A 冲击过大B 滚动阻力大C 滚动体离心力过大D 不利于轴承润滑二、判断题（本题10分，叙述正确的题目在括号中填入T，错误填入F，回答正确每小题得2分，错误倒扣2分，不答不得分，本题10分扣完为止。
）1.凸轮从动件为等加速等减速运动规律时既不存在柔性冲击也不存在刚性冲击。
（F ）2. 对回转件进行动平衡或静平衡的目的是减小转子运转时的速度波动程度。
（F）3. 凸缘联轴器适用于两轴对中不好、转速不高的应用场合。
（ F ）4.迷宫式密封主要用于无磨损且速度较高的场合。
（T ）5. 闭式蜗杆传动常设计为大传动比传动，因此需要进行热平衡计算。
（ F ）三、（本题10分）图示机构中凸轮为原动件，试计算机构自由度，若有复合铰链、局部自由度或虚约束请指出。
08-09机械设计试卷(林大)
一、填空题 （本大题共5小题，每空1分，总计10分）1、受轴向工作载荷F 作用的紧螺栓联接，螺栓和被联接件的刚度分别为C 1和C 2，其预紧力为'F ，则剩余预紧力''F 为（ ）；2、阿基米德蜗杆传动在（ ）面上的模数m 和压力角α取标准；在该平面内， 蜗杆与蜗轮的啮合相当于（ ）与（ ）的啮合；3、普通平键剖面尺寸是由（ ）确定的，而键长是由（ ）确定的；4、按所受载荷和应力的不同，轴可分为 传动轴、（ ）和（ ）三种。
5、带传动主要失效形式是（ ）和（ ）。
二、选择题 （在每题若干个选项中选出正确的选项填在括号内， 本大题共5小题，每空2分，总计10分） 1、齿轮弯曲强度计算中的齿形系数与（ ）无关。
A.模数mB.齿数zC.压力角αD.变位系数x2、多排链的排数不宜过多，这主要是因为排数过多则（ ）。
A.给安装带来困难B.各排链受力不均严重C.链传动轴向尺寸过大D.链的质量过大 3、按当量弯矩计算轴的强度时，公式22)T (α+=MM ca中，系数α是考虑（ ）而设立的修正系数。
A.材料抗弯与抗扭的性能不同B.弯曲应力和扭转切应力的循环性质不同C.强度理论的要求4、巴氏合金通常用于作滑动轴承的（ ）。
A.轴套 B.轴承衬 C.含油轴瓦 D.轴承座5、下列联轴器中，能补偿两轴的相对位移并可缓冲、吸振的是( )。
A.凸缘联轴器B.齿式联轴器C.万向联轴器D.弹性柱销联轴器三、简答题 （本大题共4小题，每题6分，总计24分）1、什么是带传动的弹性滑动现象？与打滑有何不同？2、非液体摩擦滑动轴承需要进行哪几种条件性计算，为什么？3、为什么闭式蜗杆传动要进行热平衡计算？可采取哪些措施改善散热条件？4、联接螺纹都具有良好的自锁性，为什么有时还需要防松装置？试各举出两个机械防松和摩擦的例子。
四、分析题（本大题共4小题，每题6分，总计24分）1、写出一维雷诺方程式，并分析图示三种情况，哪一种有可能形成流体动压润滑油膜？?为什么2、一对闭式软齿面直齿轮传动，其齿数与模数有两种方案：a）m=4mm，z1=20，z2=60； b）m=2mm，z1=40，z2=120，其它参数都一样。
2009机械科学研究院硕士入学考试机原答案
2009机械科学研究院硕士入学考试《机械原理》试题答案一、填空题（共26分）1、 B 、等于2、 B .为90º3、 Z 2=48; 左旋；βcos 2)(21z z m n a +='，变为；调整螺旋角β4、 不一定；一定5、 大端： 212121,,R R m m ===αα6、 齿数；齿宽7、 a , b, c ; c8、 C ; D9、 C10、逆时针；右旋 二、总分：14分。
(1)5分；(2)4分；(3)5分(1)计算自由度F n p p =--=⨯-⨯-=32342511L H(2)高副低代，机构简图见图a 。
(3)结构分析(图b)该机构为Ⅱ级机构。
三、总分20分。
(1)12分；(2)8分(1)CB B C v v v +=，t n t n CBCB B C C C a a a a a a ++=+=，v pb B v =μ，v pc C v =μ，v bc CB v =μa b B a =πμ '，a b n CB a n =''2μ，a n c CB a t =2''μ，a n C a n =πμ3'，a n c C a t =3''μ，a c C a =πμ '(2)∆BCE ∆bcp ，得E 点，vE =0；∆BCF ∆b c ''π，得F 点，a F =0四、总分20分。
（1）5分；（2）5分；（3）5分；（4）5分；（1）l l l l AB BC min max +=+=80mm其它二杆之和l l AD CD +=90mm即l l min max +<其它二杆之和，且连架杆l AB 为l min 。
该机构为曲柄摇杆机构。
有曲柄，即AB 杆为曲柄。
（3分）（2）该机构为曲柄摇杆机构，故有摇杆。
摇杆摆角范围ϕ=90 。
（3分）（3）有急回性，且θ=30 ，故K =+-=+-=()()()().180180180301803014 θθ。
2009年全国硕士研究生入学统一考试真题加答案
2009年全国硕士研究生入学统一考试英语试题Section I Use of EnglishDirections:Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1. (10 points)Research on animal intelligence always makes me wonder just how smart humans are.1 the fruit-fly experiments described in Carl Zimmer‘s piece in the Science Times on Tuesday. Fruit flies who were taught to be smarter than the average fruit fly 2 to live shorter lives. This suggests that 3 bulbs burn longer, that there is an 4 in not being too terrifically bright.Intelligence, it 5 out, is a high-priced option. It takes more upkeep, burns more fuel and is slow 6 the starting line because it depends on learning — a gradual 7 — instead of instinct. Plenty of other species are able to learn, and one of the things they‘ve apparently learned is when to 8 .Is there an adaptive value to 9 intelligence? That‘s the question behind this new research. I like it. Instead of casting a wistful glance 10 at all the species we‘ve left in the dust I.Q.-wise, it implicitly asks what the real11 of our own intelligence might be. This is 12 the mind of every animal I‘ve ever met.Research on animal intelligence also makes me wonder what experiments animals would 13 on humans if they had the chance. Every cat with an owner, 14 , is running a small-scale study in operant conditioning. we believe that 15 animals ran the labs, they would test us to 16 the limits of our patience, our faithfulness, our memory for terrain. They would try to decide what intelligence in humans is really 17 , not merely how much of it there is. 18 , they would hope to study a 19 question: Are humans actually aware of the world they live in? 20 the results are inconclusive.1. [A] Suppose [B] Consider [C] Observe [D] Imagine2. [A] tended [B] feared [C] happened [D] threatened3. [A] thinner [B] stabler [C] lighter [D] dimmer4. [A] tendency [B] advantage [C] inclination [D] priority5. [A] insists on [B] sums up [C] turns out [D] puts forward6. [A] off [B] behind [C] over [D] along7. [A] incredible [B] spontaneous [C]inevitable [D] gradual8. [A] fight [B] doubt [C] stop [D] think19. [A] invisible [B] limited [C] indefinite [D] different10. [A] upward [B] forward [C] afterward [D] backward11. [A] features [B] influences [C] results [D] costs12. [A] outside [B] on [C] by [D] across13. [A] deliver [B] carry [C] perform [D] apply14. [A] by chance [B] in contrast [C] as usual [D] for instance15. [A] if [B] unless [C] as [D] lest16. [A] moderate [B] overcome [C] determine [D] reach17. [A] at [B] for [C] after [D] with18. [A] Above all [B] After all [C] However [D] Otherwise19. [A] fundamental [B] comprehensive [C] equivalent [D] hostile20. [A] By accident [B] In time [C] So far [D] Better stillSection II Reading ComprehensionPart ADirections:Read the following four texts. Answer the questions below each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1. (40 points)Text1Habits are a funny thing. We reach for them mindlessly, setting our brains on auto-pilot and relaxing into the unconscious comfort of familiar routine. ―Not choice, but habit rules the unreflecting herd,‖ William Wordsworth said in the 19th century. In the ever-changing 21st century, even the word ―habit‖ carries a ne gative connotation.So it seems antithetical to talk about habits in the same context as creativity and innovation. But brain researchers have discovered that when we consciously develop new habits, we create parallel synaptic paths, and even entirely new brain cells, that can jump our trains of thought onto new, innovative tracks.But don‘t bother trying to kill off old habits; once those ruts of procedure are worn into the hippocampus, they‘re there to stay. Instead, the new habits we deliberately ingrain into ourselves create parallel pathways that can bypass those old roads.―The first thing needed for innovation is a fascination with wonder,‖ says Dawna Markova, author of ―The Open Mind‖ and an executive change consultant for Professional Thinking Part ners. ―But we are taught instead to ‗decide,‘ just as our president calls himself ‗the Decider.‘‖ She adds, however, that ―to decide is to kill off all possibilities but one. A good innovational thinker is always exploring the many other possibilities.‖A ll of us work through problems in ways of which we‘re unaware, she says. Researchers in the late 1960 covered that humans are born with the capacity to2approach challenges in four primary ways: analytically, procedurally, relationally (or collaboratively) and innovatively. At puberty, however, the brain shuts down half of that capacity, preserving only those modes of thought that have seemed most valuable during the first decade or so of life.The current emphasis on standardized testing highlights analysis and procedure, meaning that few of us inherently use our innovative and collaborative modes of thought. ―This breaks the major rule in the American belief system — that anyone can do anything,‖ explains M. J. Ryan, author of the 2006 book ―This Year I Will...‖ and Ms. Markova‘s business partner. ―That‘s a lie that we have perpetuated, and it fosters commonness. Knowing what you‘re good at and doing even more of it creates excellence.‖ This is where developing new habits comes in.21. The view of Wordsworth habit is claimed by beingA. casualB. familiarC. mechanicalD. changeable.22. The researchers have discovered that the formation of habit can beA. predictedB. regulatedC. tracedD. guided23.‖ ruts‖(in li ne one, paragraph 3) has closest meaning toA. tracksB. seriesC. characteristicsD. connections24. Ms. Markova‘s comments suggest that the practice of standard testing ? A, prevents new habits form being formedB, no longer emphasizes commonnessC, maintains the inherent American thinking modelD, complies with the American belief system25. Ryan most probably agree thatA. ideas are born of a relaxing mindB. innovativeness could be taughtC. decisiveness derives from fantastic ideasD. curiosity activates creative mindsText 2It is a wise father that knows his own child, but today a man can boost his paternal (fatherly) wisdom –or at least confirm that he‘s the kid‘s dad. All he needs to do is shell our $30 for paternity testing kit (PTK) at his local drugstore – and another $120 to get the results.More than 60,000 people have purchased the PTKs since they first become available without prescriptions last years, according to Doug Fog, chief operating officer of Identigene, which makes the over-the-counter kits. More than two dozen companies sell DNA tests Directly to the public , ranging in price from a few hundred dollars to more than $2500.3Among the most popular : paternity and kinship testing , which adopted children can use to find their biological relatives and latest rage a many passionate genealogists-and supports businesses that offer to search for a family‘s geographic roots .Most tests require collecting cells by webbing saliva in the mouth and sending it to the company for testing. All tests require a potential candidate with whom to compare DNA.But some observers are skeptical, ―There is a kind of false precision being hawked by people claiming they are doing ancestry testing,‖ says Trey Duster, a New York University sociologist. He notes that each individual has many ancestors-numbering in the hundreds just a few centuries back. Yet most ancestry testing only considers a single lineage, either the Y chromosome inherited through men in a father‘s line or mito chondrial DNA, which a passed down only from mothers. This DNA can reveal genetic information about only one or two ancestors, even though, for example, just three generations back people also have six other great-grandparents or, four generations back, 14 other great-great-grandparents.Critics also argue that commercial genetic testing is only as good as the reference collections to which a sample is compared. Databases used by some companies don‘t rely on data collected systematically but rather lump together information from different research projects. This means that a DNA database may differ depending on the company that processes the results. In addition, the computer programs a company uses to estimate relationships may be patented and not subject to peer review or outside evaluation.26.In paragraphs 1 and 2 , the text shows PTK‘s ___________.[A]easy availability[B]flexibility in pricing[C] successful promotion[D] popularity with households27. PTK is used to __________.[A]locate one‘s b irth place[B]promote genetic research[C] identify parent-child kinship[D] choose children for adoption28. Skeptical observers believe that ancestry testing fails to__________.[A]trace distant ancestors[B] rebuild reliable bloodlines[C] fully use genetic information[D] achieve the claimed accuracy29. In the last paragraph ,a problem commercial genetic testing faces is __________.4[A]disorganized data collection[B] overlapping database building30. An appropriate title for the text is most likely to be__________.[A]Fors and Againsts of DNA testing[B] DNA testing and It‘s problems[C]DNA testing outside the lab[D] lies behind DNA testingText 3The relationship between formal education and economic growth in poor countries is widely misunderstood by economists and politicians alike progress in both area is undoubtedly necessary for the social, political and intellectual development of these and all other societies; however, the conventional view that education should be one of the very highest priorities for promoting rapid economic development in poor countries is wrong. We are fortunate that is it, because new educational systems there and putting enough people through them to improve economic performance would require two or three generations. The findings of a research institution have consistently shown that workers in all countries can be trained on the job to achieve radical higher productivity and, as a result, radically higher standards of living.Ironically, the first evidence for this idea appeared in the United States. Not long ago, with the country entering a recessing and Japan at its pre-bubble peak. The U.S. workforce was derided as poorly educated and one of primary cause of the poor U.S. economic performance. Japan was, and remains, the global leader in automotive-assembly productivity. Yet the research revealed that the U.S. factories of Honda Nissan, and Toyota achieved about 95 percent of the productivity of their Japanese countere pants a result of the training that U.S. workers received on the job.More recently, while examing housing construction, the researchers discovered that illiterate, non-English- speaking Mexican workers in Houston, Texas, consistently met best-practice labor productivity standards despite the complexity of the building industry‘s work.What is the real relationship between education and economic development? We have to suspect that continuing economic growth promotes the development of education even when governments don‘t force it. After all, that‘s how education got started. When our ancestors were hunters and gatherers 10,000 years ago, they didn‘t have time to wonder much about anything besides finding food. Only when humanity began to get its food in a more productive way was there time for other things.As education improved, humanity‘s productivity potential, they could in turn afford more education. This increasingly high level of education is probably a necessary, but not a sufficient, condition for the complex political systems required by advanced5economic performance. Thus poor countries might not be able to escape their poverty traps without political changes that may be possible only with broader formal education. A lack of formal education, however, doesn‘t const rain the ability of the developing world‘s workforce to substantially improve productivity for the forested future. On the contrary, constraints on improving productivity explain why education isn‘t developing more quickly there than it is.31. The author holds in paragraph 1 that the important of education in poor countries ___________.[A] is subject groundless doubts[B] has fallen victim of bias[C] is conventional downgraded[D] has been overestimated32. It is stated in paragraph 1 that construction of a new education system __________.[A]challenges economists and politicians[B]takes efforts of generations[C] demands priority from the government[D] requires sufficient labor force33.A major difference between the Japanese and U.S workforces is that __________.[A] the Japanese workforce is better disciplined[B] the Japanese workforce is more productive[C]the U.S workforce has a better education[D] ]the U.S workforce is more organize34. The author quotes the example of our ancestors to show that education emerged __________.[A] when people had enough time[B] prior to better ways of finding food[C] when people on longer went hung[D] as a result of pressure on government35. According to the last paragraph , development of education __________.[A] results directly from competitive environments[B] does not depend on economic performance[C] follows improved productivity[D] cannot afford political changesText 4The most thoroughly studied in the history of the new world are the ministers and political leaders of seventeenth-century New England. According to the standard history of American philosophy, nowhere else in colonial America was ―So much6important attached to intellectual pursuits ‖ Accord ing to many books and articles, New England‘s leaders established the basic themes and preoccupations of an unfolding, dominant Puritan tradition in American intellectual life.To take this approach to the New Englanders normally mean to start with the Puritans‘ theological innovations and their distinctive ideas about the church-important subjects that we may not neglect. But in keeping with our examination of southern intellectual life, we may consider the original Puritans as carriers of European culture adjusting to New world circumstances. The New England colonies were the scenes of important episodes in the pursuit of widely understood ideals of civility and virtuosity.The early settlers of Massachusetts Bay included men of impressive education and influence in England. `Besides the ninety or so learned ministers who came to Massachusetts church in the decade after 1629,There were political leaders like John Winthrop, an educated gentleman, lawyer, and official of the Crown before he journeyed to Boston. There men wrote and published extensively, reaching both New World and Old World audiences, and giving New England an atmosphere of intellectual earnestness.We should not forget , however, that most New Englanders were less well educated. While few crafts men or farmers, let alone dependents and servants, left literary compositions to be analyzed, The in thinking often had a traditional superstitions quality. A tailor named John Dane, who emigrated in the late 1630s, left an account of his reasons for leaving England that is filled with signs. sexual confusion, economic frustrations , and religious hope-all name together in a decisive moment when he opened the Bible, told his father the first line he saw would settle his fate, and read th e magical words: ―come out from among them, touch no unclean thing , and I will be your God and you shall be my people.‖ One wonders what Dane thought of the careful sermons explaining the Bible that he heard in puritan churched.Mean while , many se ttles had slighter religious commitments than Dane‘s, as one clergyman learned in confronting folk along the coast who mocked that they had not come to the New world for religion . ―Our main end was to catch fish. ‖36. The author notes that in the seventeenth-century New England___________.[A] Puritan tradition dominated political life.[B] intellectual interests were encouraged.[C] Politics benefited much from intellectual endeavors.[D] intellectual pursuits enjoyed a liberal environment.37. It is suggested in paragraph 2 that New Englanders__________.[A] experienced a comparatively peaceful early history.[B] brought with them the culture of the Old World[C] paid little attention to southern intellectual life[D] were obsessed with religious innovations738. The early ministers and political leaders in Massachusetts Bay__________.[A] were famous in the New World for their writings[B] gained increasing importance in religious affairs[C] abandoned high positions before coming to the New World[D] created a new intellectual atmosphere in New England39. The story of John Dane shows that less well-educated New Englanders were often __________.[A] influenced by superstitions[B] troubled with religious beliefs[C] puzzled by church sermons[D] frustrated with family earnings40. The text suggests that early settlers in New England__________.[A] were mostly engaged in political activities[B] were motivated by an illusory prospect[C] came from different backgrounds.[D] left few formal records for later referencePart BDirections:Directions: In the following text, some sentences have been removed. For Questions (41-45), choose the most suitable one from the list A-G to fit into each of the numbered blank. There are two extra choices, which do not fit in any of the gaps. Mark your answers on ANSWER SHEET 1. (10 points)Coinciding with the groundbreaking theory of biological evolution proposed by British naturalist Charles Darwin in the 1860s, British social philosopher Herbert Spencer put forward his own theory of biological and cultural evolution. Spencer argued that all worldly phenomena, including human societies, changed over time, advancing toward perfection. 41.____________.American social scientist Lewis Henry Morgan introduced another theory of cultural evolution in the late 1800s. Morgan, along with Tylor, was one of the founders of modern anthropology. In his work, he attempted to show how all aspects of culture changed together in the evolution of societies.42._____________.In the early 1900s in North America, German-born American anthropologist Franz Boas developed a new theory of culture known as historical particularism. Historical particularism, which emphasized the uniqueness of all cultures, gave new direction to anthropology. 43._____________ .8Boas felt that the culture of any society must be understood as the result of a unique history and not as one of many cultures belonging to a broader evolutionary stage or type of culture. 44._______________.Historical particularism became a dominant approach to the study of culture in American anthropology, largely through the influence of many students of Boas. But a number of anthropologists in the early 1900s also rejected the particularist theory of culture in favor of diffusionism. Some attributed virtually every important cultural achievement to the inventions of a few, especially gifted peoples that, according to diffusionists, then spread to other cultures. 45.________________.Also in the early 1900s, French sociologist Émile Durkheim developed a theory of culture that would greatly influence anthropology. Durkheim proposed that religious beliefs functioned to reinforce social solidarity. An interest in the relationship between the function of society and culture—known as functionalism—became a major theme in European, and especially British, anthropology.[A] Other anthropologists believed that cultural innovations, such as inventions, had a single origin and passed from society to society. This theory was known as diffusionism.[B] In order to study particular cultures as completely as possible, Boas became skilled in linguistics, the study of languages, and in physical anthropology, the study of human biology and anatomy.[C] He argued that human evolution was characterized by a struggle he called the ―survival of the fittest,‖ in which weaker races and societies must eventu ally be replaced by stronger, more advanced races and societies.[D] They also focused on important rituals that appeared to preserve a people‘s social structure, such as initiation ceremonies that formally signify children‘s entrance into adulthood.[E] Thus, in his view, diverse aspects of culture, such as the structure of families, forms of marriage, categories of kinship, ownership of property, forms of government, technology, and systems of food production, all changed as societies evolved.[F]Supporters of the theory viewed as a collection of integrated parts that work together to keep a society functioning.[G] For example, British anthropologists Grafton Elliot Smith and W. J. Perry incorrectly suggested, on the basis of inadequate information, that farming, pottery9making, and metallurgy all originated in ancient Egypt and diffused throughout the world. In fact, all of these cultural developments occurred separately at different times in many parts of the world.Part CDirections:Read the following text carefully and then translate the underlined segments into Chinese. Your translation should be written carefully on ANSWER SHEET 2. (10 points)There is a marked difference between the education which every one gets from living with others, and the deliberate educating of the young. In the former case the education is incidental; it is natural and important, but it is not the express reason of the association.46It may be said that the measure of the worth of any social institution is its effect in enlarging and improving experience; but this effect is not a part of its original motive. Religious associations began, for example, in the desire to secure the favor of overruling powers and to ward off evil influences; family life in the desire to gratify appetites and secure family perpetuity; systematic labor, for the most part, because of enslavement to others, etc. 47Only gradually was the by-product of the institution noted, and only more gradually still was this effect considered as a directive factor in the conduct of the institution. Even today, in our industrial life, apart from certain values of industriousness and thrift, the intellectual and emotional reaction of the forms of human association under which the world's work is carried on receives little attention as compared with physical output.But in dealing with the young, the fact of association itself as an immediate human fact, gains in importance.48 While it is easy to ignore in our contact with them the effect of our acts upon their disposition, it is not so easy as in dealing with adults. The need of training is too evident; the pressure to accomplish a change in their attitude and habits is too urgent to leave these consequences wholly out of account. 49Since our chief business with them is to enable them to share in a common life we cannot help considering whether or no we are forming the powers which will secure this ability.If humanity has made some headway in realizing that the ultimate value of every institution is its distinctively human effect we may well believe that this lesson has been learned largely through dealings with the young.50 We are thus led to distinguish, within the broad educational process which we have been so far considering, a more formal kind of education -- that of direct tuition or schooling. In undeveloped social groups, we find very little formal teaching and training. These groups mainly rely for instilling needed dispositions into the young upon the same sort of association which keeps the adults loyal to their group.Section & Writing10Part A51. Directions:Restrictions on the use of plastic bags have not been so successful in some regions. ―White pollution ‖is still going on. Write a letter to the editor(s) of your local newspaper to1)give your opinions briefly and2)make two or three suggestionsYou should write about 100 words. Do not sign your own name at the end of the letter. Use "Li Ming" instead. You do not need to write the address.Part B52. Directions:In your essay, you should1) describe the drawing briefly,2) explain its intended meaning, and then3) give your comments.You should write neatly on ANSHWER SHEET 2. (20 points)11。
机械考研试题集锦与答案
第三章螺纹联接与螺旋传动1．常用螺纹有哪几类？哪些用于联接，哪些用于传动，为什么？哪些是标准螺纹？常用的有：三角螺纹，矩形螺纹，梯形螺纹和锯齿形螺纹。
三角螺纹用于联接，其余用于传动。
因三角螺纹自锁性好，其它螺纹传动效率高。
除矩形螺纹外，其余均为标准螺纹。
2．何谓螺纹联接的预紧，预紧的目的是什么？预紧力的最大值如何控制？螺纹联接的预紧是指在装配时拧紧，是联接在承受工作载荷之前预先受到预紧力的作用。
预紧的目的是增加螺纹联接的刚度、保证联接的紧密性和可靠性（防松能力）。
拧紧后，预紧应力的大小不得超过材料屈服极限σS的80%。
3．螺纹联接有哪些基本类型？适用于什么场合？螺纹联接有4中基本类型。
螺栓联接：用于被联接件不太厚且两边有足够的安装空间的场合。
螺钉联接：用于不能采用螺栓联接（如被联接件之一太厚不宜制成通孔，或没有足够的装配空间），又不需要经常拆卸的场合。
双头螺柱联接：用于不能采用螺栓联接且又需要经常拆卸的场合。
紧定螺钉联接：用于传递力和力矩不大的场合。
4．紧螺栓联接的强度也可以按纯拉伸计算，但须将拉力增大30%，为什么？考虑拧紧时的扭剪应力，因其大小约为拉应力的30%。
5．提高螺纹联接强度的措施有哪些？1）改善螺纹牙间的载荷分配不均；2）减小螺栓的应力幅；3）减小螺栓的应力集中；4）避免螺栓的附加载荷（弯曲应力）；5）采用合理的制造工艺。
6．为什么螺母的螺纹圈数不宜大于10圈（使用过厚的螺母不能提高螺纹联接强度）？因为螺栓和螺母的受力变形使螺母的各圈螺纹所承担的载荷不等，第一圈螺纹受载最大，约为总载荷的1/3，逐圈递减，第八圈螺纹几乎不受载，第十圈没用。
所以使用过厚的螺母并不能提高螺纹联接强度。
7．联接螺纹能满足自锁条件，为什么还要考虑防松？根据防松原理，防松分哪几类？因为在冲击、振动、变载以及温度变化大时，螺纹副间和支承面间的摩擦力可能在瞬间减小或消失，不再满足自锁条件。
这种情况多次重复，就会使联接松动，导致机器不能正常工作或发生严重事故。
安徽农业大学工学院.
安徽农业大学工学院机械设计题型样卷(五)班级学号姓名成绩一、是非题：正确的在（）中写“＋”，错误的在（）中写“－”(本大题分19小题, 每小题1分, 共19分)1、在不改变零件静强度的条件下,加大在一定载荷下零件的弹性变形量,将会降低该零件的冲击强度。
（）2、“零件”是组成机器的具有确定相对运动的构件。
( )3、采用螺纹联接时，若被联接件总厚度较大，且材料较软，强度较低，但不需要经常装拆，宜采用双头螺柱联接。
( )4、普通平键的定心精度高于花键的定心精度。
( )5、滚动轴承座圈和滚动体的常用材料是GCr15淬火，硬度为61~63HRC。
( )6、用橡胶等非金属元件作弹性元件的联轴器都是变刚度弹性联轴器。
( )7、由于轴上零件不平衡质量引起的离心力使旋转的轴产生对称循环变应力。
（）8、增大零件质量或减小零件刚度，可提高零件的自振频率。
（）9、若材料的平均极限应力σlim大于零件的平均工作应力σm，则零件的安全系数不一定总是大于1。
（）10、渐开线圆柱直齿轮传动工作时，齿面载荷的传递是通过真实的线接触进行的。
（）11、推荐链轮最大齿数z max≤120。
此限制是为了保证链速的均匀性。
( )12、按许用切（扭剪）应力计算,因为只考虑了转矩未考虑弯矩，所以这种方法只适用于传动轴不适用于转轴。
( )13、实心轴与空心轴强度相同时，空心轴的重量比实心轴轻，困此机械设计中广泛使用了空心轴。
( )14、按疲劳强度校核轴的安全系数，必须考虑应力集中;按静强度校核轴的安全系数不必考虑应力集中。
( )15、角接触球轴承的接触角α值越大，表示其承受轴向力的能力越大。
( )16、单个圆锥滚子轴承若用预紧办法可明显提高轴承刚度。
( )17、圆锥面过盈配合的锥度为1:5~1:10，锥角愈小，同样的轴向压力下可产生的摩擦力矩愈大，1:5锥面配合比1:10者容易拆卸。
( )18、19、(本大题分1、常用的V 带传动、滚子链传动及普通平键的主要失效方式分别为_____________,____________________及__________。
2009年全国硕士研究生入学统一考试农学门类联考数学真题及详解【圣才出品】
3．函数 f (x) xx2 et2 dt 的极值点为 x＝（ 0
）.
A． 1 2
B． 1 4
C．－ 1 4
D．－ 1 2
【答案】A
【解析】因 f (x) e xx2 2 (x x2 ) (1 2x)exx2 2
令 f (x) 0 ，得 x 1 ，又 2
f (x) 2exx2 2 (1 2x) e xx2 2
圣才电子书
十万种考研考证电子书、题库视频学习平
台
2009 年全国硕士研究生入学统一考试农学门类联考数学真题及详解
一、选择题：1～8 小题，每小题 4 分，共 32 分．下列每题给出的四个选项中，只有
一个选项是符合题目要求的，请将所选项前的字母填在括号内. 1．在（－π，π）内，函数 y x 的可去间断点的个数为（ ）. tan x A．0
圣才电子书
【答案】 4 3
【解析】由于
十万种考研考证电子书、题库视频学习平 台
，所以
原式
12．设 f（u，v）为二元可微函数， Z
f (sin(x
y)，e
xy
)
，则
z x
____.
【答案】 fu cos(x y) yfvexy
【解析】函数 z z(x, y) 由 z f (u, v),u sin(x y), v exy 复合而成，根据复合函
A 项， P AB P( A U B) 1 P( A U B) ，因为 P( A U B) 不一定等于 1，所以
P( AB) 不一定等于 0. B 项，只有当 P（A），P（B）为 0 或事件 A，B 相互独立时才成立. C 项，只有当 A，B 互为对立事件的时候才成立.
D 项， P( A U B) P AB 1 P( AB) 1.
机械考研真题及参考答案
机械考研真题及参考答案1.已知某机床主运动传动系统图，试分析：1）两末端件2）计算位移3）传动路线表达式4）列出平衡⽅程式并求最⼤转速m ax n 。
2. CA6140 主运动传动系统如图所⽰：①写出主运动两末端件的计算位移关系②写出⾼速传动的表达式③列出⾼速传动的平衡⽅程式求正转最⼤转速m ax n （10分）3. CA6140 主运动传动系统如图所⽰：①主轴正反转怎样实现？②⾼速传动怎样实现？③车削正反螺纹怎样实现? ④⾼速传动表达式。
（10分）4.图⽰CA6140 主运动传动系统图，1) 写出最⾼转速时的传动路线；2）写出最低转速时的传动路线；3）正反转切换是如何实现的。
5. 写出Ｙ3150E 滚齿机的如下传动链的俩末端件、计算位移并指出是内联还是外联。
（10分）（1）．范成链．（2）．差动链．（3）轴向进给链．（4）．主运动传动链IIIIIV6. 试分别分析图⽰滚齿机传动系统中：范成链，差动链，轴向进给链，主运动链的（1）俩末端件（2）计算位移（3）是内联还是外联传动链；（10分）7.在Y3150E 上加⼯Z=48，m=3的直齿轮，滚⼑头数K=1，试分析范成链：1）两末端件2）计算位移3）传动路线表达式4）平衡⽅程式5）范成挂轮齿数。
（10分）8. 已知某机床主运动传动系统图，试分析：1）两末端件2）计算位移3）传动路线表达式4）列出平衡⽅程式并求最⼤转速m ax n 。
（10分）9. 指出CA6140车床如下传动链的两末端件、计算位移并分析是内联还是外联。
（1）．主运动传动链（2）．机动进给运动传动链（3）．螺纹传动链（10分）10. 图⽰CA6140车床主运动系统。
请指出主轴正转与反转时的传动路线区别何在，⾼速与低速传动路线区别何在，主轴正转时VII 轴上的齿轮34是否转动？为什么？（10分）IIIIIV11.根据下⾯的传动系统图，1)写出传动路线表达式；2.)指出主轴Ⅴ有⼏种转速；3)列式并计算出主轴Ⅴ的最⾼转速n（转/分）。
安徽农业大学农业机械学【选修】题库.doc
农业机械学I.先进的播种机可实现开沟，播种，施肥，覆土，镇压等多工序一•次完成，不仅出苗整齐，而且省种，省肥。
2.20世纪80年代以后，农业装备的电子化，信息化已经成为发达国家农业装备技术创新的主流趋势。
3.20世纪9()年代，精细农业的发展以及智能化农业装备的应用，以高薪技术投入和科学管理取得对自然资源的最大节约及利用，促成高产，优质，低耗，环保型可持续发展的农业。
4.农业环境污染主要是指化肥，农药，地膜的大量使用和焚烧秸秆造成污染加剧的问题。
5.国外植保机械大量采用静电喷雾，低量喷雾，控滴喷雾等技术，可使药液在植物片上的有效沉积高达90%以上。
6.根据耕作用的深度和用途不同，同•把耕作机械分为两类，耕地机械和整地机械。
7.条播机一般由机架，行走装置，种了箱，排种器，开沟器，覆土器，镇压器，传动机构以及开沟深浅调节装管等组成。
8.滚堡过程分为切土，抬堡和翻堡，审堡过程分为切土，窜堡和扣堡。
9.普通犁的耕作速度为4.5-6千米每小时，高速犁的耕作速度大于7「米每小时。
10.旋耕机按旋耕刀轴的位置可分为横轴式，立轴式和斜轴式。
II.按耙片直径分，圆盘耙可分为轻型直径为460mm,中型直径为560mm,重型直径为660mm。
12.农业生产过程包括许多作业环节，各地的自然条件，作物构成和耕作速度乂有较大的差别，决定了农业机械的多样性与区域的适应性。
因此，农业机械的研制与推广必须因地制宜。
13.农业机械大多数在野外露天作业，工作环境条件恶劣因此农业机械应有较高的使用可靠性，耐磨，防腐，防震，有良好的操纵性能以及必要的安全防护设施。
14.传统耕作法乂称精细耕作法，通常是指作物生产过程中机械翻耕，耙压和中耙等组成的土壤耕作体系。
15.按与拖拉机挂结的形式不同，铮式犁可分为牵引犁，悬挂犁和半悬挂犁。
16.犁体式铮式犁的主要工作部件，一般由犁铮，犁壁，犁侧板，犁柱，犁托等组成。
17.犁侧板位于犁铮的后上方，其作用力平衡耕作是产生的侧向力与部分垂直压力。
2009年同等学力申硕机械工程真题及答案
绝密★启用前2009年同等学力人员申请硕士学位学科综合水平全国统一考试机械工程试卷第一部分必考题（共两组）第二部分选考题（共五组，任选一组）考生须知1.本试卷满分为100分，其中第一部分必考题60分，每位考生必答；第二部分选考题40分，共五组试题，任选一组作答。
多选者只按首选计分。
2.请考生务必将本人考号最后两位数字填写在本页右上角方框内。
3.考生一律用蓝色或黑色墨水笔在答题纸指定位置上按规定要求作答，未做在指定位置上的答案一律无效。
4.监考员收卷时，考生须配合监考员验收，并请监考员在准考证上签字（作为考生交卷的凭据）。
否则，若发生答卷遗失，责任由考生自负。
机械工程试卷第1页共8页第一部分必考题（两组，共60分）A组（共30分）一、填空题（本大题共8空，每空1分，共8分）1．方块图包含了与系统有关的信息，与系统的无关。
2．传递函数反映系统本身的特性，它只与系统本身的有关，与无关。
3．顺馈校正的特点是在干扰引起之前就对它进行补偿。
4．在控制系统中，当输入信号与不相等时，比较装置就会出现误差信号。
二、简答题（本大题共4小题，每小题3分，共12分）1．简述求传递函数的一般步骤。
2．何谓线性系统？其最重要特性是什么？3．对控制系统的基本性能要求有哪些？4．简述伯德图的优点。
三、论述题与计算题（本大题共2小题，每小题5分，共10分）1．论述劳斯－赫尔维茨稳定性判据的根据。
2．求图示电路u i与u0之间关系的微分方程。
ouo+R1R2机械工程试卷第2页共8页B组（共30分）一、填空题（本大题共8空，每空1分，共8分）1．按系统的自由度数进行分类，机械振动可分为：振动、振动和振动。
2．任意激励或脉冲激励下单自由度系统的响应通常只有响应，没有响应，可以借助于脉冲响应来分析，也可以采用法进行求解。
3．机构平衡的措施可分为两类：的方法和机构合理布局或的方法。
二、简答题（本大题共4小题，每小题3分，共12分）1．简述什么是随机振动。
2009年机械设计卷及答案
《机械设计》试题 闭卷A 2009年11月（参考答案）班级__________ 姓名______________ 学号_________________ 分数_______一、单项选择题（共20分, 每小题2分）1、带传动在工作时产生弹性滑动的原因之一是 C 。
A. 带与带轮间的摩擦力不够B. 带绕过带轮时离心力过大C. 带的松紧边存在拉力差D. 传递的功率过大2、在一定转速下，要减轻链传动的运动不均匀性和动载荷，设计时应 D 。
A. 增大链节距，增加链轮齿数 B. 减小链节距，减少链轮齿数C. 增大链节距，减少链轮齿数D. 减小链节距，增加链轮齿数 3、一对标准直齿圆柱齿轮传动，σ H1、σ F1是小齿轮的齿面接触应力和齿根弯曲应力，σ H2、σ F2是大齿轮的齿面接触应力和齿根弯曲应力，则下列关系 C 是正确的。
A. σ H1＞σ H2、σ F1＜σ F2B. σ H1＜σ H2、σ F1＞σ F2C. σ H1＝σ H2、σ F1＞σ F2D. σ H1＜σ H2、σ F1＝σ F24、设计一对标准直齿圆柱齿轮传动时，在保持齿轮分度圆直径不变的前提下，增大模数同时减少齿数，则 A 。
A. 接触强度不变，弯曲强度提高B. 接触强度降低，弯曲强度降低C. 接触强度提高，弯曲强度不变D. 接触强度提高，弯曲强度降低 5、蜗杆传动齿面接触疲劳强度的设计式为22212)(9HPE z Z KT d m σ≥，式中σ HP 为许用接触应力，则计算时应代入 B 。
A. 蜗杆材料的σ HP1B. 蜗轮材料的σ HP2C. σ HP1、σ HP2的平均值D. σ HP1、σ HP2中的大值 6、关于螺纹连接，下列说法 B 是正确的。
A. 矩形螺纹常用于连接B. 普通螺栓装配时受拉应力和剪应力作用C. 采用双螺母是为了增大预紧力D. 铰制孔螺栓主要承受轴向工作载荷 7、若跨距未知，设计轴的一般步骤是 A 。
安徽大学机械设计09-10第二学期试题A附答案
安徽大学2009－2010学年第 2 学期试题（ A ）卷m/s。
当载荷分）2009-2010学年第2学期试题A 答案一、填空题：1、轴的直径 轮毂的宽度；2、减小 接触；3、防止螺旋副在受载时发生相对转动；4、销轴 外链板 套筒 内链板 滚子 套筒 套筒 销轴5、面要硬，芯要韧6、小带轮包角减小7、斜齿圆柱齿轮 直齿圆锥齿轮 8、减少刀具数量及便于滚刀标准化 小 9、非承载区域10、圆锥滚子轴承 351、解：（1）根据螺栓组的受力特点分析，螺栓组连接受力分析 横向载荷：112000300044S F F N ∑=== 将载荷简化到结合面的形心点，得一旋转力矩：12000.56000T P l N m =⋅=⨯=⋅。
在旋转力矩作用下的分力：2600010608440.1414S T F N r ===⨯ 两力所夹角最小时，螺栓所受横向载荷最大，即：max 12904.7s F N ===采用普通螺栓连接，由s s fF K F '=得：1.212904.71032380.15S S K F F N f ⨯'===由强度条件可以得所求螺栓的小径为：142.4mm d ≥==2． 解：（1）12000200800100221200400r a V L d F F R N L ⋅+⋅⨯+⨯=== 21800V r V R F R N =-=127502H H FR R N ===11415R N === 21097R N ===(2) 110.68962.2S R N ==,220.68746S R N ==，S 1，S 2的方向如图所示。
217468001546a S F S +=+=>，所以轴承1被“压紧”，轴承2被“放松”。
12221546, 746a A S F N A S N =+===.(3) 121215467461.09, 0.6814151097A A e e R R ==>=== 所以，111() 1.5(0.4114150.871546)2887.7P P f XR YA =+=⨯⨯+⨯= 22 1.510971646p P f R ==⨯=。
安徽工业大学 09机械原理862A卷
安徽工业大学 2009 年招收硕士研究生专业基础课试卷（A） 科目名称：机械原理 代码：862（答案必须写在答题纸上，写在试卷上无效）一、判断题(20 分，每题 2 分) 1．满足动平衡条件的刚性转子也一定满足静平衡条件。
2．在曲柄滑块机构中,当曲柄做主动件,就必然有死点存在。
3．机器主轴作周期性速度波动时,在一个周期内其动能的增量为零。
4．蜗轮蜗杆传动，其传动比等于从动轮直径与主动轮直径之比。
5．两变位齿轮组成正传动，则两个齿轮必定都是正变位的。
6．一对直齿圆柱齿轮啮合传动，模数越大，重合度也越大。
7．直动平底从动件盘形凸轮机构工作中，其压力角始终不变。
8．加工齿轮常用范成法，但范成法加工的齿轮可能会产生根切。
9．惰轮（中介轮）能改变从动轮的转向，但不改变传动比的大小。
10．若机构的自由度为 3 时，机构肯定无确定的运动。
二、填空题（20 分，每空 1 分） 1 凸轮机构中从动件作等加速等减速运动时将产生____冲击 2 三个彼此作平面平行运动的构件共有____个瞬心，而且必定位于______________。
含 有 6 个构件的平面机构，其速度瞬心共有______个，其中至少有________个是绝对 瞬心。
3 渐开线齿轮在不同圆周上的压力角也不相同，在________圆上压力角最大；在 ___________圆上压力角为 0°；在_________圆上压力角取标准值。
4 在斜齿轮传动中，除了用改变________来凑中心距外，还可以用_______来凑中心距。
5 蜗杆机构传动的主动件是_________，阿基米德蜗杆在中间平面（又称主平面）内蜗轮 与蜗杆的啮合相当于_________的啮合 6 说 出 两 种 变 回 转 运 动 为 直 线 运 动 的 机 构 ： ___________________ ， _____________________。
7 由于三角螺纹的当量摩擦系数比矩形螺纹的_____，三角螺纹的传动效率比矩形螺纹-A 1 -的传动效率_____。
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安徽農業大學
招收研究生入学考试试题
课程名称：机械原理与设计（A）
（要求：所有答案必须写在答题纸上，写在试题或草稿纸上一律无效）
一、填空题（每小题3分，共30分）
1.构件具有的确定运动时所必须给定的独立运动参数的数目称为自由度。
2.两构件以面接触构成的运动副，称为低副。
两构件之间以线接触所组成的平面运动副,成为高副
3.三心定理是指：作平面运动的构件共有3个瞬心，它们位于同一直线上
4.渐开线标准直齿圆柱齿轮分度圆齿厚与分度圆齿槽宽相等。
端面齿厚s 等于端面齿槽宽e的渐开线直齿圆柱齿轮称为标准直齿圆柱齿轮
5.一对渐开线标准直齿圆柱齿轮的正确啮合条件是两齿轮模数和分度圆上的压力角应分别相等。
ω和许可的不均
6. 飞轮设计的基本问题是根据机器实际所需的平均速度
m
J。
匀系数δ来确定飞轮的转动惯量
F
7.带传动中，带所受到的应力
8.常用的联接螺纹是三角形螺纹。
9. 6205轴承是深沟球轴承，轴承内径为25 mm。
10. 在蜗杆传动中，由于材料和结构上的原因，蜗杆螺旋部分的强度总是高于蜗轮轮齿的强度，所以失效常发生在蜗轮轮齿上。
二、单项选择题（每小题2分，共20分）
1.通常情况下，避免滚子从动件凸轮机构运动失真的合理措施是____C___。
A、增大滚子半径
B、减小滚子半径
C、增大基圆半径
D、减小基圆半径
2.在偏置曲柄滑块机构中，当取滑块为原动件时，死点位置 C 。
A、有一个
B、没有
C、有两个
D、有三个
3.铰链四杆机构中存在曲柄时，曲柄 B 是最短构件。
A、一定
B、不一定
C、一定不
满足杆长之和条件:
①最短杆为机架-----双曲柄机构;
②最短杆的相邻杆为机架----曲柄摇杆机构;
③最短杆的相对杆为机架-----双摇杆机构.
不满足杆长之和条件：
无论以哪个杆作机架,均为双摇杆机构
4.用标准齿条刀具加工正变位渐开线直齿圆柱外齿轮时，刀具的中线与齿轮
的分度圆__ B___。
A、相切
B、相离
C、相割
5.机器中安装飞轮的一个原因是为了 A 。
A、减小速度波动
B、达到稳定运转
C、消除速度波动
D、使惯性力达到平衡，减小机器振动
6.斜齿圆柱齿轮传动的重合度比直齿圆柱齿轮传动的重合度 A 。
A、大
B、相等
C、小
这个其实从计算公式就可以得出的结论：
ε=εa+ε b
直齿中，β=0，εb=b*sinβ/（π*m）=0
而直齿和斜齿εa的计算公式式完全一样的。
所以其他参数完全一样的情况下，斜齿的β>0，那么εb>0，所以斜齿的重合度肯定会大于直齿的重合度。
7.不发生根切的渐开线标准直齿圆柱齿轮的齿根圆 B 大于基圆。
A、一定
B、不一定
C、一定不
故当齿数时，正常齿制渐开线标准直齿圆柱齿轮的基圆大于齿根圆；齿数，
基圆小于齿根圆
8.在有张紧轮装置的带传动中，当张紧轮装在带内侧时应安装在__A_____。
A、靠近大带轮
B、靠近小带轮
C、两带轮的中间
D、在任何处都没关系
带传动中,要将张紧轮置于松边内侧且靠近大带轮处
9.对于工作温度较高或较长的轴，轴系固定结构可采用____C___。
A、两端固定安装的深沟球轴承
B、两端固定安装的角接触轴承
C、一端固定，另一端游动的型式
D、两端游动安装的结构型式
10.机械零件由于某些原因不能_____D______时称为失效。
A、工作
B、连续工作
C、负载工作
D、正常工作
机械零件的主要失效形式机械零件由于某些原因不能正常工作时,称为失效
三、判断题：回答对或错（每小题2分，共20分）
1.速度瞬心是指两构件相对运动时相对速度相等的点。
（错）
2.在曲柄滑块机构中，只要滑块为主动件，就一定存在死点。
（对）
3.在铰链四杆机构中，若以最短杆为原动件，该机构即为曲柄摇杆机构。
（对）
4.一对直齿圆柱齿轮中心距改变后，这对齿轮的节圆半径也改变。
（对）
5.平面摩擦的自锁条件是压力角大于摩擦角。
（对）
6.一对外啮合的斜齿圆柱齿轮的螺旋线方向相同。
（错）
内啮合是相同的但是外啮合是相反
7.一对直齿圆锥齿轮的重合度按其当量齿轮重合度计算。
（对） 直齿圆锥齿轮的啮合传动特点 一对锥齿轮的啮合传动相当于其当量齿轮的啮合传动
8. 在渐开线圆柱齿轮传动中，相啮合的大小齿轮在相互接触点的齿面接触应
力是相等的。
（对）
9. 受轴向载荷的紧螺栓联接的螺栓所受的总拉力是预紧力与工作拉力之和。
（对）
10. 自锁的蜗杆传动，常常用于间歇工作的场合。
（错） 蜗轮蜗杆减速机具有自锁性
四、简要回答下列问题：（每小题6分，共30分）
1. 既然虚约束对于机构的运动实际上不起约束作用，那么在实际机构中为什么又常常存
在虚约束？
机械设计中虚约束往往是根据某些实际需要采用的，如为了增强支承刚度，或为了改善受力，
或为了传递较大功率等需要，
2. 铰链四杆机构有曲柄存在的条件是什么？
（ 1 ）最短杆与最长杆长度之和应小于或等于其余两杆长度之和；
（ 2 ）连架杆与机架中至少有一个是最短杆。
3. 说明规定蜗杆分度圆直径d1（或直径系数q ）标准值的实际意义？
规定蜗杆分度圆直径d1或蜗杆直径系数q 为标准值是为了有利于蜗杆传动中心距的标准化。
4. 要求传动比 i ＝3的标准直齿轮传动，齿数设计成z 1＝10，z 2＝30是否可行？为什么？ 不可以，虽然传动比可以实现，但是z 1＝10标准直齿轮会发生根切，会减小齿轮根部的强度。
对于闭式硬齿面或开式齿轮传动：一般取 z1=17~25以便增大模数提高弯曲强度 大、小齿轮的齿数最好互质，使磨损均匀
5. 试分析齿轮产生齿面磨损的主要原因，它是哪一种齿轮传动的主要失效形式？防止磨损失效的最有效办法是什么？
齿面磨损齿面磨损通常有两种情况：一种是由于灰尘、金属微粒等进入齿面间引起的磨损；另一种是由于齿面间相对滑动摩擦引起的磨损。
在开式传动中，一方面改善齿轮润滑条件，另一方面对齿轮进行热处理，包括表面淬火、渗氮、调质。
五、计算图示机构的自由度。
该机构需要几个原动件运动确定；并说明复合铰链，局部自由度和虚约束的位置。
（10分）
六、一对正确安装的标准渐开线直齿轮传动，已知2mm m =， 其中心距100a mm =，
传动比4i =。
（1）齿轮是否会产生根切
（2）计算两个齿轮的分度圆直径和齿顶圆直径（10分）
七、为提高图示支架的刚度：
（1）提出简易可行的解决办法，并完成其结构示意图；
八、图示为蜗杆-斜齿圆柱齿轮两级传动。
1）确定中间轴II 和从动轴III 的转向（从左向右看是顺时针还是逆时针）；
2）确定蜗杆的旋向；
3）为使轴Ⅱ上轴向力能抵消一部分，斜齿轮3的旋向如何？并说明齿轮3上的轴向力方向。
（10分）
九、如图所示轮系，设已知：11440/min n r =, 各轮齿数为120z =，390z =，'380z =，
520z =。
试：求传动比1H i 及行星架H 的转速H n 。
要求先区分轮系，再分别列式计算。
（12分）。