喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預(yù)覽哦。下載后都有，請放心下載，文件全都包含在內(nèi)，有疑問咨詢QQ:1064457796
任務(wù)書及開題報(bào)告
題 目 對稱傳動式剪板機(jī)
學(xué) 院
專業(yè)班級
學(xué)生姓名
指導(dǎo)教師
填 表 說 明
1．任務(wù)書中內(nèi)容由指導(dǎo)教師本人填寫，并經(jīng)專業(yè)審定后，下發(fā)給學(xué)生。
2．開題報(bào)告中內(nèi)容由學(xué)生根據(jù)任務(wù)書要求，經(jīng)查閱資料、調(diào)研后填寫。
3．開題報(bào)告一般在開始畢業(yè)設(shè)計(jì)（論文）工作的第1-2周內(nèi)完成，由各專業(yè)或教研室組織安排開題。
4．開題報(bào)告應(yīng)包括以下幾個(gè)方面的內(nèi)容：
（1）課題的來源及選題的依據(jù)、意義，課題在理論或?qū)嶋H應(yīng)用方面的價(jià)值以及可能達(dá)到的水平。
（2）課題在國內(nèi)外研究現(xiàn)狀和水平。
（3）課題研究的內(nèi)容及擬采用的技術(shù)路線或研究方法（包括設(shè)計(jì)、實(shí)驗(yàn)、加工測試條件等）。
（4）研究中的主要難點(diǎn)以及解決問題的方法。
（5）設(shè)計(jì)（論文）的工作進(jìn)度計(jì)劃（以周為單位）。
（6）主要參考文獻(xiàn)。
5．填寫不下可另加附頁。
6．本材料裝訂順序?yàn)椋喝蝿?wù)書、開題報(bào)告。
13
畢業(yè)設(shè)計(jì)（論文）任務(wù)書
題 目
對稱傳動式剪板機(jī)
題目類型
設(shè)計(jì) □ 論文 □ 其他
學(xué)生姓名
學(xué) 號
學(xué) 院
專業(yè)班級
指導(dǎo)教師
職 稱
系 主 任
主管院長
任務(wù)下達(dá)日期
日
任務(wù)完成日期
任務(wù)要求（課題目標(biāo)、主要內(nèi)容、技術(shù)參數(shù)、基本要求等）
一、課題目標(biāo)：
根據(jù)機(jī)械專業(yè)人才培養(yǎng)目標(biāo)的要求，培養(yǎng)學(xué)生綜合運(yùn)用本專業(yè)知識解決實(shí)際工程問題的能力和科學(xué)方法。畢業(yè)設(shè)計(jì)（論文）是普通高等院校各專業(yè)教學(xué)計(jì)劃的重要組成部分，是大學(xué)期間學(xué)生畢業(yè)前的最后學(xué)習(xí)階段，是學(xué)習(xí)的深化與升華的重要過程。通過畢業(yè)設(shè)計(jì)，讓學(xué)生綜合運(yùn)用所學(xué)的基礎(chǔ)理論、專業(yè)知識和基本技能，通過計(jì)算分析，提高分析與解決實(shí)際問題的能力以及繪圖能力。掌握機(jī)械機(jī)構(gòu)的設(shè)計(jì)、檢測方法、材料的性能分析和選擇能力。該設(shè)計(jì)是“對稱傳動式剪板機(jī)”的設(shè)計(jì)。
二、主要內(nèi)容：
1、撰寫開題報(bào)告；
2、完成整機(jī)方案的論證及設(shè)計(jì)；
3、完成傳動系統(tǒng)的詳細(xì)設(shè)計(jì)；
4、完成執(zhí)行機(jī)構(gòu)的詳細(xì)設(shè)計(jì)；
5、完成驅(qū)動系統(tǒng)的詳細(xì)設(shè)計(jì)；
6、完成控制系統(tǒng)的詳細(xì)設(shè)計(jì)；
7、完成潤滑系統(tǒng)的詳細(xì)設(shè)計(jì)；
8、繪制該剪板機(jī)的零件圖、裝備圖，運(yùn)動仿真，模具設(shè)計(jì)，數(shù)控編程。
三、技術(shù)參數(shù)：
1、滑塊行程：108mm
2、剪板機(jī)剪切力:16t
3、剪板次數(shù)：60次/min
四、基本要求：
1、要求學(xué)生根據(jù)畢業(yè)設(shè)計(jì)題目單獨(dú)查找文獻(xiàn)及相關(guān)資料。
2、能熟練應(yīng)用AutoCAD2014、solidworks等軟件，對所設(shè)計(jì)的剪板機(jī)繪制裝配圖及主要零部件圖。
3、對外文資料應(yīng)能進(jìn)行獨(dú)立翻譯。
4、對設(shè)計(jì)內(nèi)容能根據(jù)四年中所學(xué)的知識進(jìn)行合理的分析解釋。
5、設(shè)計(jì)說明書按《齊齊哈爾大學(xué)畢業(yè)設(shè)計(jì)（論文）工作手冊》要求格式寫。
6、按《齊齊哈爾大學(xué)畢業(yè)設(shè)計(jì)（論文）工作手冊》要求格式書寫手寫說明書草稿，手寫版外文翻譯草稿各一份。說明書成稿和譯文成稿按畢業(yè)設(shè)計(jì)說明書打印要求打印。
7、所設(shè)計(jì)裝置應(yīng)滿足結(jié)構(gòu)簡單，制造容易、維護(hù)方便、安全、精度高。
注：任務(wù)書必須由指導(dǎo)教師本人填寫
畢業(yè)設(shè)計(jì)（論文）開題報(bào)告
一、選題的依據(jù)、意義和理論或?qū)嶋H應(yīng)用方面的價(jià)值
對稱傳動式剪板機(jī)是一種典型的對稱傳動的機(jī)械。主要用于剪裁各種尺寸金屬板材的直線邊緣。該設(shè)備應(yīng)用廣泛，具有結(jié)構(gòu)簡單，維修方便，經(jīng)濟(jì)實(shí)用的優(yōu)點(diǎn)，在使用金屬板材較多的工業(yè)部門，都需要根據(jù)尺寸要求對板材進(jìn)行切斷加工。所以剪板機(jī)就成為各個(gè)工業(yè)部門使用最為廣泛的板料剪斷設(shè)備。隨著我國制造業(yè)的發(fā)展，剪板機(jī)機(jī)床的發(fā)展越來越成為機(jī)械制造行業(yè)的中流砥柱，剪板機(jī)廣泛適用于航空、汽車、農(nóng)機(jī)、五金、電機(jī)電器、儀器儀表、醫(yī)療機(jī)械等行業(yè)。我國的剪板機(jī)大都是結(jié)構(gòu)繁瑣、操作復(fù)雜、安全性不足、噪音大等缺點(diǎn)。所以設(shè)計(jì)出一臺運(yùn)行平穩(wěn)、安全可靠、操作維修方便、廉價(jià)的剪板機(jī)，在解決原有設(shè)計(jì)缺點(diǎn)的基礎(chǔ)上并且進(jìn)行創(chuàng)新，制造出一臺具有實(shí)際意義的剪板機(jī)。
二、本課題在國內(nèi)外的研究現(xiàn)狀
目前，剪板機(jī)在國內(nèi)外研究主要用于汽車、航空航天、電子和家用電器等領(lǐng)域。這都需要大量的金屬板殼零件，特別是汽車行業(yè)要求生產(chǎn)規(guī)?；?、車型個(gè)性化和覆蓋件體型一體化。進(jìn)入21世紀(jì)，我國汽車制造業(yè)飛速發(fā)展，面對這一形勢，我國板材加工工藝及相應(yīng)的沖壓都有了長足的進(jìn)步。近年來，對剪板機(jī)的要求由原來的簡單操作到實(shí)現(xiàn)可自動化、可靠性高、噪聲小、使用壽命長的過度。
在國外，特別是一些工業(yè)發(fā)達(dá)國家的剪板機(jī)水平已達(dá)到一個(gè)相當(dāng)高的水平。像美國、德國、日本這樣的發(fā)達(dá)國家在剪板機(jī)方面已經(jīng)有了成熟的技術(shù)，其表現(xiàn)為：具有較好的可靠性，耐用度和精度保持性等。大大地節(jié)約了生產(chǎn)制造時(shí)間，在提高加工零件尺寸精度的同時(shí)，提高了勞動生產(chǎn)率，從而降低了產(chǎn)品的制造成本，增強(qiáng)了產(chǎn)品在市場上的競爭能力。其發(fā)展趨勢向著平穩(wěn)，高精度、高質(zhì)量、節(jié)能、環(huán)保、數(shù)控、智能的方向發(fā)展。
三、課題研究的內(nèi)容及擬采取的方法
課題研究的內(nèi)容：
本課題主要完成對稱傳動式剪板機(jī)的設(shè)計(jì)，包括：
1、電動機(jī)的選擇其中包括電動機(jī)的類型、功率、結(jié)構(gòu)等；
2、帶傳動的設(shè)計(jì)包括V型帶的類型和帶根數(shù)的選擇、大帶輪小帶輪的設(shè)計(jì)；
3、軸的設(shè)計(jì)包括軸各段長度、直徑、強(qiáng)度校核及材料的選擇的設(shè)計(jì)；
4、齒輪的設(shè)計(jì)包括齒輪類型、模數(shù)齒數(shù)、精度等級、材料等的設(shè)計(jì)；
5、曲柄滑塊和凸輪的設(shè)計(jì)；
6、離合器和減速器的設(shè)計(jì)。
采用方法：
1、先收集資料，確定方案，確定選材；
2、再擬定結(jié)構(gòu)方案，進(jìn)行設(shè)計(jì)計(jì)算并校核；
3、繪制裝配草圖，校核有關(guān)技術(shù)參數(shù)；
4、運(yùn)用AutoCAD2014、solidworks等軟件繪制裝配圖和相關(guān)零件圖，并通過模具設(shè)計(jì)、運(yùn)動仿真、數(shù)控編程對有關(guān)零件進(jìn)一步分析。
四、課題研究中的主要難點(diǎn)以及解決的方法：
一、主要難點(diǎn)：
1、軸的優(yōu)化，關(guān)于軸在什么部位選擇什么樣的直徑和長度是個(gè)難點(diǎn)。
2、根據(jù)設(shè)計(jì)要求，剪切力為16t，連桿所承受的力較大，曲柄所需的驅(qū)動力矩較大。為了降低成本，使用小功率電動機(jī)，就得加上飛輪的蓄能作用，這樣結(jié)構(gòu)及質(zhì)量又會增加。
二、解決方法：
1、（1）可按軸所受的扭矩初步估算軸所需的直徑，將初步得出的直徑作為軸段的最小直徑Dm，然后按軸上零件的裝配方案和定位要求，從Dm處逐一確定各段軸徑；
（2）軸的各段長度主要根據(jù)個(gè)零件與配合部分的軸向尺寸和相鄰零件間必要的空隙來確定。
2、設(shè)計(jì)使用三角帶輪傳動（傳遞能量大）。
五、畢業(yè)設(shè)計(jì)（論文）工作進(jìn)度計(jì)劃
第一周——第二周（2015.3.9——2015.3.23）查閱資料，編寫開題報(bào)告，擬訂設(shè)計(jì)方案。
第三周（2015.3.23——2015.3.30）完成外文翻譯的原告和翻譯。方案設(shè)計(jì)，比較各種方案，確定最終的設(shè)計(jì)方案。包括工藝方案、傳動方案、結(jié)構(gòu)方案、控制方案等。
第四周——第十二周（2015.3.31——2015.5.18）設(shè)計(jì)計(jì)算，根據(jù)設(shè)計(jì)方案，確定主要零件的結(jié)構(gòu)形狀、尺寸，進(jìn)行強(qiáng)度校核，制作模具，完成數(shù)控編程部分，繪制零件草圖。
第十三周（2015.5.19——2015.5.25）利用AutoCAD2014、Solidworks按著GB標(biāo)準(zhǔn)繪制零件圖、裝配圖，并進(jìn)行三維建模工作。
第十四周（2015.5.26——2015.6.1）進(jìn)行整體設(shè)計(jì)，內(nèi)部結(jié)構(gòu)設(shè)計(jì)，模具和數(shù)控加工部分的檢查校正，編寫設(shè)計(jì)說明書。
第十五周（2015.6.2——2015.6.10）設(shè)計(jì)說明書，外文資料、文獻(xiàn)的翻譯、排版、打印、裝訂；設(shè)計(jì)圖紙的打印輸出；整理畢業(yè)設(shè)計(jì)資料準(zhǔn)備答辯。
第十六周(2015.6.11——2015.6.25）畢業(yè)設(shè)計(jì)答辯，整理畢業(yè)設(shè)計(jì)資料。
六、主要參考文獻(xiàn)（或資料）
[1] 濮良貴，紀(jì)名剛．機(jī)械設(shè)計(jì)[S]．第7版．北京：高等教育出版社，2004.
[2] 宋鍵. 制造業(yè)與現(xiàn)代化．機(jī)械工程學(xué)報(bào)，2002（12）．
[3] 邢建東.工程材料基礎(chǔ)[M]，機(jī)械工業(yè)出版社，2004.
[4] 孫桓，陳作模．機(jī)械原理．第七版．北京：高等教育出版社，2011．
[5] 席慧智，谷萬里，高玉芳．機(jī)械工程材料[M]. 哈爾濱：哈爾濱工程大學(xué)出版社，2009.
[6] 劉品.機(jī)械加工工藝編制手冊[M].北京.機(jī)械工業(yè)出版社,1993.12.
[7] 韓進(jìn)宏.互換性與技術(shù)測量[M].北京：機(jī)械工業(yè)出版社,2007.
[8] 王世剛. 機(jī)械設(shè)計(jì)實(shí)踐[M]. 哈爾濱: 哈爾濱工程大學(xué)出版社, 2007.
[9] 劉鴻文．材料力學(xué)（上、下冊）[M]．第三版．北京：高等教育出版社，2008.
[10] 大連理工大學(xué)工程畫教研室．機(jī)械制圖．第四版．北京：高等教育出版社，1993.
[11] 熊弟霖、肖正揚(yáng)、孫武、梁婉瑩主編．自動機(jī)械機(jī)構(gòu)學(xué)[M]．北京：中國輕工業(yè)出版社，2009.5．
[12] 梁應(yīng)彪．板材剪切力的測試.北京：鍛壓技術(shù)，1992，第六期．
[13] 郭芝俊，左寶山，張桂芳，張寶興主編．機(jī)械設(shè)計(jì)手冊便覽[M]．天津科學(xué)技術(shù)社，2008．
[14] 許震宇主編.機(jī)械零件[M].北京:人民教育出版社.2009.
[15] 九所院校合編.機(jī)械零件附冊[M].天津:天津大學(xué)出版社.2010.
[16] 俞新陸，何德譽(yù)．鍛壓手冊，第3卷，鍛壓車間設(shè)備．北京：機(jī)械工
業(yè)出版社，2002．
[17] 左健民．液壓與氣壓傳動．第四版．北京：機(jī)械工業(yè)出版社,2010．
[18] 崔占全，邱平善．機(jī)械工程材料．哈爾濱：哈爾濱工程大學(xué)出版社，2001．
[19] 哈爾濱工業(yè)大學(xué)理論力學(xué)教研組．理論力學(xué)（上、下冊）．第六版．北京：高等教育出版社，1997．
[20] G.N.Sandor,R.E.Kaufman: Kinematics Synthesis of Geared Linkages,J.Mechanisms,Vol.5,1970.
[21] Strezove L, Herbertson J,Experimental studies of interfacial heat transfer and initial solidfication pertinent to strip casting [J]. ISIJ Inteinational,2003,38 (9).
[22] Shigley J E,Uicker J J.Theory of machines and mechanics.New York:MeGraw-Hill Book company,1980.
[23] Smit T.Thin gauge hot strip [J] .A report on the ISS symposium [C] .Toronto: steel Times International, 2000,(7).
[24] 趙建剛,徐靜,孟廣兵,趙春禾,王元輝. 液壓擺式剪板機(jī)的技術(shù)改進(jìn) [J]. 重型機(jī)械科技. 2007(01) .
[25] 趙中華，徐新成．結(jié)點(diǎn)偏置曲柄滑塊機(jī)構(gòu)的運(yùn)動特性．鍛壓裝備與制造技術(shù).2004年第3期．
指導(dǎo)教師意見
指導(dǎo)教師______________簽字
年 月 日
專業(yè)審查意見
審查人______________簽字
年 月 日
Downloaded From: http:/asmedigitalcollection.asme.org/ on 04/13/2013 Terms of Use: http:/asme.org/terms GEAR AND SHAFT INTRODUCTION Abstract: The important position of the wheel gear and shaft cant falter in traditional machine and modern machines. The wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box. The passing to process to make them can is divided into many model numbers, useding for many situations respectively. So we must be the multilayers to the understanding of the wheel gear and shaft in many ways . Key words: Wheel gear; Shaft In the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn. Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoid. The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load. Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-helical fears have point contact with each other, which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between a crossed heli cal gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is ,a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix Downloaded From: http:/asmedigitalcollection.asme.org/ on 04/13/2013 Terms of Use: http:/asme.org/terms angle should be used as the driver if both gears have the same hand. Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears. Worm gearing are either single or double enveloping. A single-enveloping gearing is one in which the gear wraps around or partially encloses the worm. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single- enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles are equal for a 90- deg. Shaft angle. When gears are to be used to transmit motion between intersecting shaft, some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered. Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of squr gears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often good design practice to go to the spiral bevel gear, which is the bevel counterpart of the helical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered. It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution. The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of worm gears. A shaft is a rotating or stationary member, usually of circular cross section, having mounted upon it such elementsas gears, pulleys, flywheels, cranks, sprockets, and other power- transmission elements. Shaft may be subjected to bending, tension, compression, or torsional loads, acting singly or in combination with one Downloaded From: http:/asmedigitalcollection.asme.org/ on 04/13/2013 Terms of Use: http:/asme.org/terms another. When they are combined, one may expect to find both static and fatigue strength to be important design considerations, since a single shaft may be subjected to static stresses, completely reversed, and repeated stresses, all acting at the same time. The word “shaft” covers numerous variations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating, nor subjected to torsion load. A shirt rotating shaft is often called a spindle. When either the lateral or the torsional deflection of a shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses. The reason for this is that, if the shaft is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are safe; it is almost always necessary to calculate them so that he knows they are within acceptable limits. Whenever possible, the power- transmission elements, such as gears or pullets, should be located close to the supporting bearings, This reduces the bending moment, and hence the deflection and bending stress. Although the von Mises-Hencky- Goodman method is difficult to use in design of shaft, it probably comes closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft has failed in service. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment, and surface finish and whether or not shot peening is necessary in order to achieve the required life and reliability. Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two inertias I1 and I2 traveling at the respective angular velocities W1 and W2, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyzing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in static, which will have to be studied separately for earth geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of interest is the heat- dissipating surfaces. The various types of clutches and brakes may be classified as fllows: 1. Rim type with internally expanding shoes 2. Rim type with externally contracting shoes 3. Band type 4. Disk or axial type 5. Cone type 6. Miscellaneous type The analysis of all type of friction clutches and brakes use the same general Downloaded From: http:/asmedigitalcollection.asme.org/ on 04/13/2013 Terms of Use: http:/asme.org/terms procedure. The following step are necessary: 1. Assume or determine the distribution of pressure on the frictional surfaces. 2. Find a relation between the maximum pressure and the pressure at any point 3. Apply the condition of statical equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions. Miscellaneous clutches include several types, such as the positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others. A positive-contact clutch consists of a shift lever and two jaws. The greatest differences between the various types of positive clutches are concerned with the design of the jaws. To provide a longer period of time for shift action during engagement, the jaws may be ratchet- shaped, or gear-tooth-shaped. Sometimes a great many teeth or jaws are used, and they may be cut either circumferentially, so that they engage by cylindrical mating, or on the faces of the mating elements. Although positive clutches are not used to the extent of the frictional-contact type, they do have important applications where synchronous operation is required. Devices such as linear drives or motor- operated screw drivers must run to definite limit and then come to a stop. An overload-release type of clutch is required for these applications. These clutches are usually spring-loaded so as to release at a predetermined toque. The clicking sound which is heard when the overload point is reached is considered to be a desirable signal. An overrunning clutch or coupling permits the driven member of a machine to “freewheel” or “overrun” because the driver is stopped or because another source of power increase the speed of the driven. This type of clutch usually uses rollers or balls mounted between an outer sleeve and an inner member having flats machined around the periphery. Driving action is obtained by wedging the rollers between the sleeve and the flats. The clutch is therefore equivalent to a pawl and ratchet with an infinite number of teeth. Magnetic fluid clutch or brake is a relatively new development which has two parallel magnetic plates. Between these plates is a lubricated magnetic powder mixture. An electromagnetic coil is inserted somewhere in the magnetic circuit. By varying the excitation to this coil, the shearing strength of the magnetic fluid mixture may be accurately controlled. Thus any condition from a full slip to a frozen lockup may be obtained. Introduction of Machining Have a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete. Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of Downloaded From: http:/asmedigitalcollection.asme.org/ on 04/13/2013 Terms of Use: http:/asme.org/terms a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining. Strict precision and good surface finish, Machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low- tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing. Primary Cutting Parameters Cutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool. Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry - to the tip plane and cutter angle characteristics - for each cutting process must be correct. Cutting speed is the cutting edge of work piece surface rate, it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts - with knives. Generally, the more hard work piece material, the lower the rate. Progressive Tool to speed is cut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to。 Depth of penetration of a cutting tool - to inches dollars - is the tool to the work piece distance. Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishing, deeper penetration of a cutting tool depth. Wears of Cutting Tool We already have been processed and the rattle of the countless cracks edge tool, we learn that tool wear are basically three forms : flank wear, the former flank wear and V-Notch wear. Flank wear occurred in both the main blade occurred vice blade. On the main blade, shoulder removed because most metal chip mandate, which resulted in an increase cutting force and cutting temperature increase, If not allowed to check, That could lead to the work piece Downloaded From: http:/asmedigitalcollection.asme.org/ on 04/13/2013 Terms of Use: http:/asme.org/terms and the tool vibration and provide for efficient cutting conditions may no longer exist. Vice-bladed on, it is determined work piece dimensions and surface finish. Flank wear size of the possible failure of the product and surface finish are also inferior. In most actual cutting conditions, as the principal in the former first deputy flank before flank wear, wear arrival enough, Tool will be effective, the results are made unqualified parts. As Tool stress on the surface uneven, chip and flank before sliding contact zone between stress, in sliding contact the start of the largest, and in contact with the tail of zero, so abrasive wear in the region occurred. This is because the card cutting edge than the nearby settlements near the more serious wear, and bladed chip due to the vicinity of the former flank and lost contact wear lighter. This results from a certain distance from the cutting edge of the surface formed before the knife point Ma pit, which is usually considered before wear. Under normal circumstances, this is wear cross- sectional shape of an arc. In many instances and for the actual cutting conditions, the former flank wear compared to flank wear light, Therefore flank wear more generally as a tool failure of scale signs. But because many authors have said in the cutting speed of the increase, Maeto surface temperature than the knife surface temperatures have risen faster. but because any form of wear rate is essentially temperature changes by the significant impact. Therefore, the former usually wear in high-speed cutting happen. The main tool flank wear the tail is not processed with the work piece surface in contact, Therefore flank wear than wear along with the ends more visible, which is the most common. This is because the local effect, which is as rough on the surface has hardened layer, This effect is by cutting in front of the hardening of t he work piece. Not just cutting, and as oxidation skin, the blade local high temperature will also cause this effect. This partial wear normally referred to as pit sexual wear, but occasionally it is very serious. Despite the emergence of the pits on the Cutting Tool nature is not meaningful impact, but often pits gradually become darker If cutting continued the case, then there cutter fracture crisis. If any form of sexual allowed to wear, eventually wear rate increase obviously will be a tool to destroy failure destruction, that will no longer tool for cutting, cause the work piece scrapped, it is good, can cause serious damage machine. For various carbide cutting tools and for the various types of wear, in the event of a serious lapse, on the tool that has