共查询到20条相似文献，搜索用时 62 毫秒
1.
吕庆洲 《淮南职业技术学院学报》2006,6(1):59-63
为了更加精确、快速地设计曲柄摇杆机构,利用借助辅助圆设计曲柄摇杆机构的原理,通过对曲柄摇杆机构各杆件长度以及运动时所处的几个特殊的几何位置关系进行了数学计算和分析,得到了具有急回特性的曲柄摇杆机构获得最佳传动角的条件和一组设计计算公式;根据所给的具体条件,选择不同的计算公式,采用直接计算法或计算机辅助设计法,确定具有最佳传动角和急回特性的曲柄摇杆机构的机构布置以及各杆件的结构尺寸。 相似文献
2.
3.
常勇 《福建工程学院学报》2007,5(1):83-87
将运动倒置原理与"辅助角方法"巧妙、有机地结合起来,并引入虚拟的曲柄摇杆机构为桥梁,成功地得到了按行程速比系数K兼按最佳传动角(γmin推)max或许用传动角[γ]设计Ⅰ型、Ⅱ型平面双曲柄机构的解析方法. 相似文献
4.
朱康良 《兰州石化职业技术学院学报》2002,2(2):16-18
在深入分析对心型曲柄摇杆机构的几何特性和杆长关系的基础上 ,推导出许用传动角和最小传动角与摆角之间的不等关系式 ;提出了一种按最小传动角解析设计对心型曲柄摇杆机构的方法 ,能同时满足许用传动角要求与最小杆长和要求 相似文献
5.
首先采用解析算法设计平面曲柄摇杆机构。然后在满足给定的摇杆长度及摆角Ф和行程速比系数K(或极位夹角θ)的前提下，借助计算机进行机械最优化设计，方便地求得具有最优传动角的平面曲柄摇杆机构。 相似文献
6.
7.
探讨给定行程速比系数K,摇杆摆角ψ,以及摇杆长度l3(机架长度l4),曲柄长度l1(连杆长度l2)等,运用辅助圆图解设计曲柄摇杆机构的方法。 相似文献
8.
张洪强 《宁波职业技术学院学报》2008,12(2):88-90
建立了曲柄摇杆机构位置关系方程,采用Pro（E进行计算机辅助设计,解出构件尺寸,画出机构运动简图,最后进行仿真设计。此方法可推广应用到所有4杆机构设计上,并在教学实践中取得了很好的效果。 相似文献
9.
顾蓉蓉 《南通职业大学学报》2011,25(1):97-100
为使连杆上某点的运动能最佳逼近给定的轨迹,同时考虑机构运转灵活轻便、结构尺寸合理,须采用最优化设计方法来解决。文章以曲柄摇杆机构为例,对该机构进行了尺寸综合和运动分析,并建立了其优化设计模型,给出了具体的优化设计实例及优化结果。结果表明,采用优化设计方法,可使连杆上的某一点精确再现预定轨迹。 相似文献
10.
一、前言用传统的手工图解法进行机构分析，存在精度低、作图繁的缺点。将CAD技术应用于一些简单、常用机构的图解法分析与设计，既可继承传统图解法原理简单、方法直观的优点，又可克服其缺点。AutoCAD是当今世界上应用广泛的计算机工程制图软件，利用计算机强大的计算功能和卓越的图形处理能力，可对产品进行高效的辅助设计、分析和优化。更重要的是，这种方法可用于CAD/CAM技术，以取得更明显的效益。二、机构分析与设计实例1. 平面四杆机构分析举例如图1（a）所示曲柄摇杆机构，曲柄AB为原动件，摇杆CD为从动件，已知四杆长为：… 相似文献
11.
12.
13.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
14.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
15.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
16.
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
17.
18.
RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
19.
20.
唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献