机械类英语论文
『壹』 急求机械专业相关英文论文(带中文翻译)
这里有很多的,你可以找下有没有?我找了好长时间才找到的哦.
中文免费论文地址集锦
一、 综合类
1、蓝之韵论文
http://www.21blue.com 门类较全。
2、学生大论文中心
http://www.studa.com/newpaper/
3、蜂朝无忧论文网
http://www.51lunwen.com/main/index.asp
门类很全。
4、论文下载中心
http://www.studa.net/paper/
门类很全。
5、论文帝国
http://www.papersempire.com/
二、 教育类
1、教研论文交流中心
http://www.k12.com.cn/teacher/resource/lunwen/
以中小学教育为主,基础教育、英语教学文章居多。
2、教育教学论文网
http://www.minaol.com/gb/art/ttd/index.asp
以教育论文为主,包含:语文论文 美术论文 物理论文
化学论文 英语论文 历史论文 德育论文 教学论文
数学论文 音乐论文 生物论文 自然论文 体育论文
地理论文 摄影论文 劳动技术 农村教育 毕业论文
素质论文 医学论文 电子电器学 思维科学 计算机论文
活动课教学 书法篆刻论文 创新教育研究 心理健康教育
西部教育论文 信息技术论文
3、教育论文
http://dhzyzz.porcelain-china.com/teach.asp
4、中国园丁网论文大观
http://www.teacher.net.cn/papers
5、北大附小学校教师的文章:
http://www.bdfx.net.cn/5jslw.htm
三、 专业类
1、优秀论文杂志
http://www.interpapers.com/kj/
以科技类为主。
2、论文资料网
http://www.51paper.net/
以财经经济管理类为主。
3、法律图书馆
http://www.law-lib.com/
文如其名。
4、法学论文资料库
http://www.law-lib.com/lw/
文如其名。
5、中国总经理网论文集
http://www.cnceo.com/school/lwj.asp
6、mba职业经理人论坛
http://mba.001.com.cn/mbamba.htm
7、中国农业在线-农业论文
http://www.agrionline.net.cn/keji/lunwenzy/
8、体育论文
http://www.zxty.net/proct4.htm
9、财经学位论文下载中心
http://www.forumcn.com/sblw/
10、公开发表论文_深圳证券交易所
http://www.sse.org.cn/sse/yjkw/gkfblw.asp
11、中国路桥资讯网论文资料中心
http://www.lqzx.com/lunwen.htm
12、论文商务中心
http://doc.cei.gov.cn/
13、法律帝国:
http://www.fl365.com/gb/lawthinker/bbs/default.asp
四、 论文写作教学类
1、学术论文
http://www.hrexam.com/advanced1.htm
其实是学术论文的写作网站。
五、 博硕士论文
1、论文统计
http://www.sci.com.cn/
实际上就是万方的论文统计。
2、台湾博硕士论文咨讯网
http://datas.ncl.e.tw/theabs/00/
3、北京大学学位论文样本收藏
http://www.lib.pku.e.cn/xwlw.html
4、学位论文 (清华大学)
http://www.lib.tsinghua.e.cn/new/thesis.html
]
中国科技论文在线http://www.paper.e.cn/
论文中国 :http://www.chinawrite.com/
新浪论文网分类:http://dir.sina.com.cn/search_dir/jy/lw/
中国论文联盟:http://www.lwlm.com/
大学生论文库http://www.syiae.com/lunwen
论文资料网:http://www.51paper.net/
论文下载中心:http://www.studa.net/paper/
毕业论文网:http://www.bylw.com/
学位论文:http://www.lib.tsinghua.e.cn/NEW/thesis.html
无忧论文网:http://www.51lunwen.com/
北京语言文化大学论文库:http://lib.blcu.e.cn/dt1000/bys/bys.htm
『贰』 求一篇机械类的英语论文及翻译
IntroctionMachining aims to generate the shape of work-piece form a solid body,or to improve the tolerances and surface finish of a previously formed work-piece,by removing excess materials in the form of chips. Machining is capable of creating geometric configurations,tolerances, and surface finishes often unobtainable by any other technique.However, machining removes materials, which has already been paid for, in the form of relatively small particles that are more difficult to recycle and are in greater danger of becoming mixed. Therefore,developments often aim at recing or-if at all possible-eliminating machining, especially in mass proction.For these reasons, machining has lost some important markets, yet, at the same time, it has also been developing and especially having captured new markets with the application of numerical control.Some feel for the important of machining may be gained from the observation that in 1983 there were about 2 million metal-cutting machine tools in the unite states ( of which some 5% were numerically controlled ) and that labor and overhead costs amounted to $125 billion, or 3% of the GNP.
『叁』 机械专业论文英语翻译 高分急求~!
滚珠丝杠传动中最常用的高速加工机床,因为他们的高刚度,它允许精确定位的工具,切削力。带宽的环路是一种重要的因素,而设计的控制器? uences高速定位精度。带宽可扩大了增加反馈收益,直到结构谐振所激动。此外,非线性行为的存储卡螺母和干扰,如外部切削力、非线性摩擦、转矩波动影响运动精度。在这篇文章中,由于结构振动问题,非线性摩擦、转矩波动,和其他外部干扰都在一个系统化的方式。
『肆』 有谁有 机械类英语小论文(英文)
我有。。。。。。。。。。。
『伍』 我想要一篇关于机械类的英文文章,5000字左右,用来毕业英译中,专业性强点儿的,老师事儿妈,谢谢各位啦~
去国外的大学教授主页上找吧,一般他们都会公布自己写的论文。
http://fccr.ucsd.e/JournalArticles.html
这上面都一些机械控制的论文,不知道是不是符合你的要求
上面那个连接随便点一个进去就是一篇论文。。。
http://fccr.ucsd.e/pubs/B09.pdf 这就是论文了
http://fccr.ucsd.e/pubs/BB08b.pdf 这是第二篇
『陆』 急求一篇机械类英文论文,英文5000字以上,要有中文翻译呀,急急急!~~~~~
中国是世界上机械发展最早的国家之一。中国的机械工程技术不但历史悠久,而且成就十分辉煌,不仅对中国的物质文化和社会经济的发展起到了重要的促进作用,而且对世界技术文明的进步做出了重大贡献.传统机械方面,我国在很长一段时期内都领先于世界。到了近代由于特别是从18世纪初到19世纪40年代,由于经济社会等诸多原因,我国的机械行业发展停滞不前,在这100多年的时间里正是西方资产阶级政治革命和产业革命时期,机械科学技术飞速发展,远远超过了中国的水平。这样,中国机械的发展水平与西方的差距急剧拉大,到十九世纪中期已经落后西方一百多年。 新中国建立后特别是近三十年来,我国的机械科学技术发展速度很快。向机械产品大型化,精密化、自动化和成套化的趋势发展。在有些方面已经达到或超过了世界先进水平。总的来说,就目前而言中国机械科学技术的成就是巨大的,发展速度之快,水平之高也是前所未有的。这一时期还没有结束,我国的机械科学技术还将向更高的水平发展。只要我们能够采取正确的方针、政策、用好科技发展规律并勇于创新,我国的机械工业和机械科技一定能够振兴,重新引领世界机械工业发展潮流。 就小型夯实机械而言: 上世纪60年代以前,我国小型夯实机械非常缺乏,很多小型场地的夯实基本上采用人工夯实。 上世纪60年代初期,长沙建设机械研究所与北京建筑工程学院等单位合作,在群众性技术革新成果的基础上总结发明了具有中国特色的蛙式夯实机,1962年获国家科技发明奖。蛙式夯实机结构简单,维修、使用方便,很快成为我国60年代夯实机械的主导产品。据不完全统计蛙式夯实机累计产量达到50000多台,在我国经济建设中发挥了重要作用。70年代以后,蛙式夯实机逐渐被性能更先进的振动冲击夯和振动平板夯所替代,目前蛙式夯实机已经很少,基本被淘汰。 1964年,长沙建设机械研究所开发了HB120型内燃式夯实机,开始由上海工程机械厂生产,后来主要由津市洞庭工程机械厂生产,年产量200台左右。80年代,内燃式夯实机产品质量有较大提高,曾出口东南亚和非洲地区。90年代以后,内燃式夯实机产销售量也在逐渐减少,目前只有少数小型民营企业生产。 1977年,长沙建设机械研究所和柳州市建筑机械厂开发了我国第一台HZR250型和HZR70型振动平板夯,这两种产品分别于1979 年和1982年通过了由建设部组织的鉴定。随后义乌建筑机械厂、四平建筑机械厂、安阳振动器厂、津市洞庭工程机械厂等多家企业都开始生产振动平板夯。1986年长沙建设机械研究所又开发了较大的HZR450型振动平板夯。上世纪90年代以后,振动平板夯在我国有了较快的发展,产品品种、规格和生产企业增多,国外的振动平板夯陆续进入中国市场。 1983年,长沙建设机械研究所和湖北振动器厂联合开发了我国第一台HZR70型振动冲击夯,1984年通过了由建设部组织的鉴定,1985年获建设部科技进步三等奖。由于振动冲击夯具有压实效果好、生产率高、体积和重量小、轻便灵活等突出特点,深受用户欢迎,得到了迅速的推广使用,并很快发展到资江机器厂、新乡第三机床厂和津市洞庭工程机械厂等几十家企业生产。振动冲击夯虽然比振动平板夯开发晚,但发展速度、产销量和使用广泛性比振动平板夯大得多,目前已成为我国夯实机械中产销量最大的主导产品。上世纪90年代以后,国外的振动平板夯陆续进入中国市场。 振动冲击夯和振动平板夯在我国的成功开发,不仅为我国建设施工部门提供了性能先进的夯实机械,取得了良好的经济效益和社会效益,而且使我国夯实机械技术向前跨进了一大步,缩短了与世界先进水平的差距,促进了我国压实机械的发展。 就机械加工而言: 热加工 铸造 据考古发现,在北京平谷、昌平、房山等处曾出土了公元前16世纪(商代)的青铜礼器。 明永乐年间(1403~1424年),北京制造出享誉世界的明永乐大铜钟(46.5吨)和钟楼大铜钟(63吨)及铁钟(25吨),采用分炉熔化、地坑造型和陶范法铸造。 20世纪50年代以前,北京在铸造上采用粘土砂手工造型。1955年,北京第一机床厂开始采用漏模造型、双面模型型板及铁型板和标准砂箱造型。1965年,开始采用塑料模型。 1980 年,北京市机电研究院与北京玛钢厂研制成功工频无芯塞杆底注式保温浇注电炉。1982年,该院与北京机床铸
『柒』 求一篇机械方面的英文论文3000字
对压缩机单螺杆专用加工机床的介绍更新时间
摘要:本文从四个方面介绍了国内现有单螺杆加工机床的布局和结构,并把优缺点一一列举出来,由于压缩机生产厂的单螺杆加工机床和机床资料对外保密,以上介绍难免有片面、不妥之处,因此仅供单螺杆压缩机生产厂参考。
一、介绍机床的布局
压缩机排气量的大小决定了星轮、螺杆直径的大小和啮合中心距的大小,因此螺杆直径的不同,机床的主轴与刀具的回转中心也不同。为满足加工不同直径的螺杆,目前国内单螺杆加工机床的布局大致有以下几种方案。
第一种:机床的主轴与刀具回转中心的中心距为固定式
机床的主轴与刀具回转中心的中心距为固定式,中心距不可调整。加工几种直径的螺杆就需要几种中心距规格不同的机床。
优点:机床的结构简单。
缺点:每种机床只能加工一种规格的螺杆,当市场上某种规格的压缩机螺杆需要量大时,造成一台机床加工,其他机床闲置。
第二种:机床的主轴箱为可回转式
机床可根据加工螺杆直径的大小在加工前把主轴箱旋转一个角度。这种主轴箱能够回转的机床是对上述第一种机床在使用方法上的改进,与第一种机床的结构基本相同。
优点:机床的结构简单,能适应多种规格螺杆的加工。
缺点1:主轴箱旋转后主轴回转中心线与刀具回转中心线间的距离不易精确测量。
缺点2:主轴箱旋转后主轴前端面与刀具的回转中心线间的距离减少,因此加工较大直径的螺杆受到限制。
第三种:机床的主轴箱为横向移动式
主轴箱底部与底座之间布置有矩形滑动导轨,主轴箱移动的方向垂直于主轴回转中心线并垂直于刀具回转中心线。主轴箱的动力通过花键轴传给底座内的刀具进给机构。
根据加工螺杆直径的大小,在加工前用手轮丝杠进给机构把主轴箱移动到适当位置,然后用螺钉将主轴箱固定在底座上。主轴箱的移动距离可用光栅尺检测,位置误差±0.005mm。
采用主轴箱可横向移动的一个机床就可以加工直径φ95~φ385mm之间任何一种规格的螺杆。
由于加工φ95~φ385mm直径的螺杆,造成主轴前端面与刀具回转中心线间的距离差值过大,因此在实际应用时设计成两种规格的机床,一个机床加工φ95~φ205mm直径的螺杆,另一个机床加工φ180~φ385mm直径的螺杆。
优点:机床能适应多种规格螺杆的加工,每种规格的螺杆不需要配备相应的加工机床。
缺点:机床的结构和机床的装配较前二种机床复杂,机床的造价也较前二种机床高。
二、介绍机床的主轴结构
机床主轴箱的水平主轴和底座上的立式的主轴精度的高低决定了被加工螺杆的精度,同时螺杆在压缩机中以几千转的速度高速旋转时,精度较差的螺杆会使压缩机产生发热、振动、效率低、磨损快等现象。
国内目前现有的单螺杆加工机床主轴结构大致有以下两种方案。
第一种:轴承径向游隙不可调的主轴结构
主轴前轴承采用1个双列圆柱滚子轴承和两个推力球轴承组合,该主轴使用双列圆柱滚子轴承承受径向切削力,使用两个推力球轴承承受轴向切削力。
主轴后轴承一般采用1个双列圆柱滚子轴承或采用1个向心球轴承。
这种主轴结构的优点:主轴的加工和装配简单,造价较低。
缺点1:由于主轴轴承的径向游隙不可调整,所以主轴精度较差。虽然可以利用轴承的内径和轴径的过盈配合来消除轴承的径向游隙,但每个轴承的内径和径向游隙不是一个固定值,因此设计和加工时很难给准轴径与轴承内径的配合公差。
缺点2:在市场上很难买到国产或进口的C、D级或P4、P5级的推力球轴承,机床生产厂常用普通级轴承替代使用,此举也影响了主轴精度的提高。
轴承径向游隙不可调的主轴结构适用于一般精度的普通机床,不适用于对主轴精度要求较高的机床。
第二种:轴承径向游隙可调的主轴结构
主轴前轴承采用一个P4级圆锥孔的双列圆柱滚子轴承和1个P4级的双列向心推力球轴承组合。该主轴使用圆锥孔的双列圆柱滚子轴承承受径向切削力,使用双列向心推力球轴承承受轴向切削力和部分径向切削力。
主轴后轴承一般采用1个P5级圆锥孔的双列圆柱滚子轴承。
圆锥孔双列圆柱滚子轴承的内圈和配合轴径均为1:12圆锥,用圆螺母锁紧轴承则使轴承在轴向产生一个位移并使轴承的内圈膨胀,从而达到减少或消除轴承径向游隙的目的。
这种主轴结构的优点:主轴精度较高。在主轴前端面φ230mm直径上测量主轴的端面跳动值为0.010mm。在主轴前端φ230mm外圆上测量主轴的径向跳动值为0.005mm。第二种结构的主轴精度比第一种主轴精度提高50%左右。
这种主轴结构的缺点:
主轴的加工工艺较复杂,主轴的装配也需要有经验的工人操作才能使主轴精度达到理想数值。
三、刀具进给深度的控制
不同直径的螺杆需要加工螺旋槽的深度也不同,螺旋槽的深度从几十毫米到一百多毫米不等,刀具进给机构大约需要旋转进刀几千圈才能完成一个螺杆零件的加工。
由于刀具进给机构在刀具旋转的同时还要完成进刀动作,所以一些在普通机床上常用的机械、电气控制切深的方法都不适用于单螺杆加工机床。
单螺杆加工机床的刀具进给机构采用以下不同的方法都可以达到控制进刀深度的目的。
第一种:摩擦离合器和电气开关控制刀具进给深度
它的控制原理是刀具切深增大时刀具进给机构的负载扭距增大,使刀具进给机构传动链中的摩擦离合器打滑,一个机械连杆机构触发电气开关并发出声、光信号提示操作者,此时操作者人工操作断开刀具进给机构的动力。
这种控制方法的优点是:控制方法简单及零件加工和操作不受突然断电的影响。
缺点是:加工不同直径的螺杆需要调整摩擦离合器压紧碟簧的预紧力。
由于每个螺杆材质的密度、硬度存在细微差异及刀具锋利程度也存在差异,因此使这种控制方法的精度不太准确,可能导致螺杆螺旋槽的深度公差过大。
第二种:用电磁离合器、编码器组合控制刀具进给深度
刀具进给系统中,装有电磁离合器及一对用于检测刀具转动圈数的测速齿轮和一个编码器。
结论:本文从四个方面介绍了国内现有单螺杆加工机床的布局和结构,并把优缺点一一列举出来,由于压缩机生产厂的单螺杆加工机床和机床资料对外保密,以上介绍难免有片面、不妥之处,因此仅供单螺杆压缩机生产厂参考。
Dedicated to the single screw compressor machine updated the Introction
Abstract: This paper describes four areas from the existing single-screw machine layout and structure, and put out the advantages and disadvantages of the list, because of the compressor plant single-screw machine tools and machine tool external Security information, the above introction there is inevitably one-sided and wrong, and are therefore single-screw compressor for the proction of reference works.
First, introce the layout of machine tools
Decide the size of the compressor displacement of the stars round, screw diameter, mesh size and the size of the center distance, so different in diameter screw, machine tool spindle and the rotary center are also different. To meet the processing of different diameter screw, single screw Currently the layout of machine tools in general there are several options.
The first is: machine tool rotary tool spindle center and the center distance for the fixed
Machine tool rotary tool spindle center and the center distance for the fixed, can not adjust the center distance. Processing of several of the screw diameter on the center distance required several different specifications of the machine.
Advantages: simple structure of the machine.
Disadvantage: each machine can only process a specification of the screw, when the market on a certain specification requirements when the screw compressor, resulting in a machine, other machine idle.
The second: the machine tool spindle box for rotary
Processing screw machine according to the size of the diameter at the processing before a point of rotating spindle box. Spindle box that the machine can turn on a machine at the above-mentioned article on the use of the improvements, with the first structure of a machine tool is basically the same.
Advantages: the structure of machine tool easy to adapt to a variety of specifications of the processing screw.
One disadvantage: after the rotating spindle box and the tool spindle turning center line distance between the center line of accurate measurement difficult.
2 disadvantage: after the rotating spindle spindle box and the front surface of the rotary cutter centerline distance between the rection of the larger diameter of the screw processing is limited.
The third: the machine tool spindle box for horizontal mobile
Box at the bottom of the spindle and the base there is arranged between the rectangular sliding rail, spindle box perpendicular to the direction of movement of spindle centerline and perpendicular to the centerline of the tool rotation. Through the power of the spindle box spline shaft to the base of the tool feed mechanism.
Screw diameter, according to the size of the processing in the processing of the previous round by hand to the body put into the screw spindle box moved to the appropriate location, and then screw the spindle box on a fixed base. Spindle box available from the mobile Grating detection, position error ± 0.005mm.
Horizontal spindle box can be used as a mobile machine can process diameter φ95 ~ φ385mm any kind between the screw specifications.
Φ95 ~ φ385mm processing because of the diameter of the screw, causing the front surface and the tool spindle rotation the distance between the center line of the margin is too large, the actual application in the design specifications of the machine into two, a φ95 ~ φ205mm machine screw diameter Another φ180 ~ φ385mm machine screw diameter.
Advantages: a variety of tools to adapt to the specifications of the processing screw, each screw specifications need not be provided with the appropriate machine tools.
Disadvantage: the structure of machine tools and machine tool assembly of the two kinds of more complex machine tools, machine tools than the cost of two kinds of machine tools before the high.
Second, introce the structure of machine tool spindle
The level of machine tool spindle box on the main axis and the base of the vertical axis determines the degree of precision was the precision screw machining, at the same time screw compressor at a speed of thousands of high-speed rotary switch, the accuracy of the screw will be less so that the compressor have a fever, vibration, low efficiency, such as wear and tear situation quickly.
Currently available single-screw machine spindle structure of the program has the following two.
The first is: bearing radial clearance is not adjustable spindle structure
Before spindle bearing out the use of one pairs of cylindrical roller bearings and thrust ball bearing combination of both, the main use of double row cylindrical roller bearings under radial cutting force, the use of two ball bearings to bear axial thrust cutting force.
After the general adoption of the spindle bearings out one pairs of cylindrical roller bearings or a ball bearing to the heart.
Main advantages of this structure: the main axis of the processing and assembly of simple, low cost.
One disadvantage: because the main axis of the radial bearing clearance can not be adjusted so poor precision spindle. Although the use of bearings and shaft diameter fit to eliminate the radial bearing clearance, but each bearing diameter and radial clearance is not a fixed value, so it is difficult to design and processing to the quasi-axial-radial and bearings with bore tolerances.
2 disadvantage: it is very difficult to buy in the market of domestically proced or imported, C, D or P4, P5 class thrust ball bearings, machine tool manufacturing plant commonly used alternative to the use of ordinary class bearings, which also affected the accuracy of the enhance spindle.
Bearing radial clearance adjustable spindle structure do not apply to the general accuracy of the general machine tools, does not apply to require a higher accuracy of the spindle of machine tools.
The second: the radial bearing clearance adjustable spindle structure
Before the adoption of a spindle bearing P4 class of double row tapered hole cylindrical roller bearings and a P4-class double row ball bearing thrust to the combination of heart. The use of the spindle hole of the double row tapered cylindrical roller bearings under radial cutting force, the use of double row ball bearing thrust to the heart to bear part of the axial and radial cutting force cutting force.
Spindle bearings generally used after a P5 class of double row tapered hole cylindrical roller bearings.
Double row tapered hole cylindrical roller bearings with inner ring and shaft are tapered 1:12, bearing lock nut with a round led a bearing in the axial displacement of the inner ring bearings and expansion, to rece or eliminate Bearing radial clearance purposes.
Main structure of such advantages: high precision spindle. At the front spindle diameter φ230mm noodle on the end measuring spindle Beat value of 0.010mm. Φ230mm cylindrical spindle at the front end on the radial axis measurement value of Beat 0.005mm. The second structure of the spindle of a precision spindle accuracy than the first about 50% improve.
Main disadvantage of this structure:
The principal axis of the more complicated process, the spindle assembly also has the experience necessary to make the workers to operate the spindle achieve the desired numerical accuracy.
Third, the depth of the tool feed control
Required different processing screw diameter spiral groove depth is also different from the depth of the spiral groove mm from dozens to more than 100 millimeters range around the tool into the institutions required to feed the thousands of ring rotation in order to achieve a screw machining .
Feed because of the tool in the tool rotating at the same time achieve motion feed, so on a number of general machine tools used in mechanical, electrical control method of depth of cut does not apply to single-screw machine.
Single screw machine tools give agencies into the following different methods can be feed to control the depth of purpose.
The first is: friction clutch and electrical switches to control the depth of the tool feed
Its principle is to control depth of cut increases the tool cutter feed mechanism increases the load torque so that the tool feeding mechanism of the friction transmission chain slipping clutch, a mechanical linkage concurrent silent trigger electrical switches, optical signal prompted operator, when manual operator to disconnect the tool into the power sector.
The advantages of this control method are: the control method is simple and spare parts processing and operational power from the impact of a sudden.
Disadvantage are: processing of different diameter screw to adjust the clutch friction discs pressed the preload spring.
Material because of the density of each screw, and the hardness of the existence of subtle differences in the degree of cutting tools sharp differences exist, thus the accuracy of this control method was not too accurate, may lead to screw spiral groove depth tolerance is too large.
The second: use of an electromagnetic clutch, encoder control tool into the mix to the depth of
Tool feed system, equipped with electromagnetic clutch and a tool for detecting the number of rotating ring gear and a gun encoder.
It is a tool of control principle刚接触hand screw surface encoder to start counting switch, then start counting counting device, when the rotary tool to pre-set number of laps when the cutting depth is reached, the electromagnetic clutch automatic off open to the power tool into the concurrent silent, optical signal parts prompted the operator has finished processing.
The detection device through the digital display shows the number of feed circles or feed. Torn off and the electromagnetic clutch, the tool does not only into the rotation with the vertical shaft to the sport.
The advantages of this control method are: the depth of the spiral groove screw tolerance control more accurate, because of several significant table shows the depth of processing, or want a few laps and the depth of processing or circle the number of operations is also very intuitive and user-friendly.
Disadvantage are: electrical control of machine tools at the same time more complex parts of this control method at the processing plant, if a sudden power failure, the prior data set will be lost.
If you add in the electrical control of the battery to power at the early-dimensional detection devices to maintain the job, the problem can be resolved.
Four, the control gear drive space
Single screw machine screw in the processing, e to the spiral groove in the rotary tool and the workpiece rotation to complete the synthesis process. Just cut into the workpiece when the tool in the tangential direction of rotation has been going on a greater resistance knife, cutting tool at the workpiece to be cut when the role of the spiral groove, the tool in the tangential direction of rotation has been going up against a smaller knife and even by the spiral groove thrust workpiece.
Because there is a box-hole processing machine tool, gear and other processing error, the tool axis of rotation of the drive space is too large, large amount of so-called open.
Detect drive way too much space is a fixed power input shaft and output shaft rotation shaking, in the case of the transmission structure of conventional design and manufacture of machine tools, the transmission output shaft angle space at more than ten degrees to the dozens of degrees. Transmission gap caused by too large spiral screw groove surface then there is obvious marks, thus affecting the machining accuracy of the screw.
Upon completion of the assembly machine tool axis of rotation of the drive space is too large, in fact are subject to various errors gear, creating a backlash of the gear is too large.
Machine tools in the mechanical transmission gear are used regardless of the accuracy of a few of the class, the designers take into account the gear manufacturing error, processing error box center distance, temperature, lubricating oil film thickness, the assembly error and other factors, machine design must ensure that transmission gear A certain amount of backlash, backlash decide the size of the gear tooth thickness tolerance size.
Single-screw machine has the Main Drive from other machine tool structure specificity. In order to rece transmission or reasonable gap single-screw machine tools currently used by the following two ways.
The first is: the installation at the output shaft brake
Tool at the output shaft rotating the location of cylindrical symmetry with radial brake, brake stand up to the tool front-end of the cylindrical rotary output shaft, brake for spring preload.
The working principle of the brake is generated by the friction brake to increase the output shaft damping, recing the sensitivity of the rotation axis.
Are: brake and easy does not change the structure of the original machine tool structure, the method of indirect rection to achieve the purpose of drive space, in practical applications there is a certain effect.
One disadvantage: the pre-spring brake tool because of the cylindrical output shaft to exert a greater radial force, in fact increases the load machine torque, resulting in increased motor power at the same time gears, bearings to accelerate wear and tear.
Disadvantage 2: pre-spring brake because of the output shaft of the cylindrical tool to exert a greater radial force on the possible geometry of the tool output shaft a negative impact on accuracy.
Conclusion: This article describes four areas from existing single-screw machine layout and structure, and put out the advantages and disadvantages of the list, because of the compressor plant single-screw machine tools and machine tool external Security information, the above introction there is inevitably one-sided and wrong, and are therefore single-screw compressor for the proction of reference works.
『捌』 谁有机械论文(英文版)
The multi-motor drive
Description:
The present invention concerns a drive for an escalator, which drives the stair belt and is arranged on one or both sides of the escalator at the upper and/or the lower end thereof, wherein the drive comprises a main drive wheel and at least one motor with gear and brake components.
BACKGROUND OF THE INVENTION
Different dispositions and constructional principles are known for escalator drives. Since the drive must be designed for the maximally occurring load, a relatively large and strongly dimensioned motor with a corresponding gear is necessary. Poor efficiency at the mostly prevailing partial load and the large installation volume in the case of limited space availability within an escalator construction are disadvantages of such a drive.
These disadvantages are present to a lesser degree or not at all with multi-motor drives. Such a drive for escalators and walkways, which comprises two indivial drives or two twin drives, the output gearwheels of which drive the stair chain or the plate chain and, by way of an additional gear, the handrail, is known from DE 35 26 905.
Such a construction is executed in different variants and correspondingly comprises a number of different gears and gear housings for the stair chain drive or the plate chain drive. Furthermore, the indivial drives are equipped with planetary gears, which causes relatively high costs.
The object of the present invention is to create an improved multi-motor drive for escalators, which can be implemented at favorable costs, which may be built up in a molar manner, and which covers a usual performance range.
BRIEF DESCRIPTION OF THE INVENTION
The drive according to the present invention distinguishes itself by several constructionally identical drive units being mountable distributed at the circumference of a main drive wheel, whereby the main drive wheel or its toothing need be dimensioned only for loading by a single drive unit. The main drive wheel itself thus can have a smaller width, which is of great advantage for the accommodation of the drive parts in the case of an escalator.
The drive units, in a number corresponding with power requirements, may be flange-mounted to a main gear housing identical for all performance classes. This simplifies the proction process for the entire constructional series, reces the inventory and facilitates maintenance and repairs.
The drive units are provided with torque transmitters and/or rotational speed transmitters for recognition of their mechanical loading.
Each of the drive units can furthermore be provided with a clutch which makes a selectable switching-in or switching-out of a drive unit possible.
The drive further comprises a frequency-setting device which is common to all drive units and by means of which different speeds can be set and which also serves as a starting aid. A control and regulating unit proces corresponding control and regulating commands by the processing of incoming data. The control and regulating unit causes the switching-in and switching-out of indivial drive units on the basis of actual load data from the torque transmitters, which helps to improve the electrical and mechanical efficiency and thus also reces the energy consumption.
The use of polyphase alternating current squirrel-cage motors of variable frequency and their associated control has the advantage that high torques can be proced at low rotational speeds.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained more closely in the following with the aid of an illustrative example of an embodiment thereof and is illustrated in the accompanying drawings, wherein:
FIG. 1 shows an escalator with a drive according to the invention at the upper end of the escalator;
FIG. 2 shows the drive with drive units flange-mounted on a main gear transversely to the direction of travel of the escalator;
FIG. 3 shows the drive with drive units flange-mounted on a main gear longitudinally of the direction of travel of the escalator;
FIG. 4 shows a three-dimensional illustration of the drive arrangement according to FIG. 2;
FIG. 5 shows a three-dimensional illustration of the drive arrangement according to FIG. 3; and
FIG. 6 shows a block schematic diagram and functional diagram of the drive with all associated components.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an escalator 1 with an upper end 2, below which drive units denoted by 7 and a part of a stair chain 3 are visible.
FIG. 2 shows the details of a drive, which is installed within a carrying structure 9 at the upper end 2 of the escalator 1. Three identically constructed drive units 7 drive a toothed main drive wheel 6 by way of an output gearwheel 7.6 and an intermediate gearwheel 21, and are arranged and distributed about the circumference of the main drive wheel 6. The main drive wheel 6, together with a stair chain wheel 5, are fastened on the main shaft 4 of the drive. The drive units 7 are firmly connected to a main gear housing 8 at three planar flange-connecting openings 24 formed for this purpose. When less than three drive units 7 are needed, the unused flange-connecting opening 24 may be closed by a cover and the associated intermediate gearwheel 21 is not inserted. With this construction, the same main gear housing 8 can always be used for one, two or three needed drive units 7. The axles of the drive units 7 are arranged transversely to the direction of movement of the escalator 1, which yields the advantage of a short machine room.
As example of a variant, FIG. 3 shows an arrangement of the drive units 7 parallel to the direction of movement of the escalator 1. In this manner of arrangement, the drive units 7 additionally comprise a bevel gear 7.3. Motor 7.1, clutch 7.2, brake 7.4, flywheel 7.5 and the output gearwheel 7.6, which are otherwise constructionally identical with and incorporated in the drive units 7 of FIG. 2, are present for each drive unit 7. The main gear housing 8 is likewise always the same for one, two or three drive units 7 and unused flange-connecting openings 24 can likewise be covered by a cover.
FIG. 4 is a spatial illustration of the drive according to FIG. 2 within the carrying structure 9 of the escalator 1. Two stair elements 22 are illustrated in addition to the elements shown in the preceding illustrations.
FIG. 5 is a similar spatial illustration of the drive according to FIG. 3 within the carrying structure 9 of escalator 1. The two stair elements 22 are likewise additionally shown.
The function and operation of the multi-motor drive according to the invention is to be explained more closely in the following by reference to FIG. 6. The current supply of the drive takes place as usual from local three-phase current mains 13 with phases R, S and T which are led to a main switch 14. Following thereon, the entire drive is connected through a main relay or several relays 15. There then follows a frequency-setting device 16, which by way of a relay control 23 with the relays S1, S2 to Sn feeds the motors 7.1 (M1, M2 to Mn) of the drive moles 7 at a variable frequency current and direction of rotation as provided by the frequency-setting device 16. The motors M1, M2 to Mn are, as already shown and described in the preceding, operatively connected with the main drive wheel 6 by way of gears 7.3 and output gearwheels 7.6 and intermediate gearwheels 21, which are not further illustrated here. Torque transmitters 20 (L1, L2 to Ln) for the purpose of the measurement of the actual mechanical loading of the motors M1, M2 to Mn are installed at a suitable place in the transmission between the motors M1, M2 to Mn as known in the art. The main gear wheel 6 drives a speed transmitter 19 by way of an appropriate known transmission, which similarly is not more closely illustrated.
A control and regulating unit 10 contains microprocessor and relay control components, as well as signal and data inputs and outputs. First input data line 18.1 supplies speed values from the speed transmitter 19, which are fed as actual values to an internal regulating section. The second group of input data lines 18.2 provide measurement values from the torque transmitters 20 and, through appropriate processing, cause the switching-in and switching-out of indivial drive moles 7. A third group of input data lines 18.3 supplies data from transmitters 11, which essentially concern control safety contacts and mode of operation switches. A first group of output data lines 17.1 leads to the relays 15 and to the frequency-setting device 16. A second group of output data lines 17.2 contain control signals for the relay control 23, and the third group of output data lines 17.3 provides the data to control optical signals and illumination 12.
The multi-motor drive according to the invention functions as following:
During starting-up of the escalator 1, the relay 15 for the drive is switched on, the frequency-setting device 16 is run up and at least one drive mole 7 is switched on by way of the relay control 23 by the control and regulating unit 10 according to the choice of direction and a start-up program. On reaching the target speed, the drive regulation in the control and regulating unit 10 holds the speed of travel of the escalator 1 constant within close limits independently of the load. During the now following operation of the escalator 1, the input data lines 18.2 from the torque transmitters 20 supply information about the mechanical loading of the switched-in drive moles 7 (motors M1, M2 to Mn).
In the case of low or no loading by transported persons, the drive power of the first motor M1 may suffice, and the further motors M2 to Mn remain switched off. If a full loading with a tendency to lasting overload is signalled by the torque transmitter L1, the next motor M2 is switched on after a defined time. The signals from the two torque transmitters L1 and L2 are now monitored in the control and regulating unit 10 and a further, not illustrated motor M3 may be switched in according to analog criteria when the load limit values of the motors M1 and M2 are exceeded. The third motor, denoted by Mn in the illustration, is to indicate that, in principle, a greater number of drive moles 7 can be provided. For practical and economic reasons, however, the number of drive moles 7 will probably remain restricted to three or at most four.
The procere is reversed when the mechanical loading drops. The no longer needed motors 7.1 are then switched off in the sequence beginning with the motor Mn switched on last. If a uniform wear of the drive moles 7 is desired, this can be taken into consideration by way of an additional measurement of the switched-on times of the indivial drive moles 7 and the indivial drive moles 7 can thus be switched on and off selectably and not according to an always identical sequence.
As already mentioned, the number of the drive moles 7 is not limited to the illustrated three items. Drive moles 7 proced in large quantities can be very favorable in price, so that it could be feasible to provide a greater number, for example 4 to 6, drive moles 7. With appropriately adapted control programs in the control and regulating unit 10, the greater amount of data resulting therefrom can be processed without problems.
The use of direct current motors for the drive moles 7 is also possible in principle with appropriately-adapted control and regulating techniques as known in the art. Alternating current motors with squirrel cage armatures are preferably used because of their simple mode of construction and ease of service. Moreover, efficient and likewise cheap frequency-setting devices or frequency converters are available.
Normal spur gearwheels, by means of which an optimum mechanical efficiency is achieved, may be used for the drive arrangement according to FIG. 2. Cone wheel gears, by means of which a practically equal efficiency is achieved by comparison with spur gearwheels, are advantageously used as bevel gears 7.3 for the drive arrangement according to FIG. 3.
The main gear housing 8 can be so constructed that both drive arrangements, those according to FIG. 2 as well as those according to FIG. 3, can be realized. The main drive housing 8 then correspondingly has twice as many flange-connecting openings 24. The intermediate gearwheels 21 can be the same at the same position for both drive arrangements.
The drive arrangement according to the invention can also be used for other kinds of conveying equipment, for example for walkways and mercalators in horizontal and oblique construction.
『玖』 机械专业英语论文
3K字的,
这个 问题不是很大,
吧,给你帮忙的,给你的,
做的,