基于Solidwork的同軸式三級(jí)圓柱齒輪減速器設(shè)計(jì)【三維SW】【含4張CAD圖紙+PDF圖】
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畢業(yè)設(shè)計(jì)(論文)題目
基于Solidwork的同軸式三級(jí)圓柱齒輪減速器
一、 課題背景
減速器是一種由封閉在剛性殼體內(nèi)的齒輪傳動(dòng)、蝸桿傳動(dòng)或齒輪—蝸桿傳動(dòng)所組成的獨(dú)立部件,常用在動(dòng)力機(jī)與工作機(jī)之間作為減速的傳動(dòng)裝置;在少數(shù)場(chǎng)合下也用作增速的傳動(dòng)裝置,這時(shí)就稱(chēng)為增速器。減速器由于結(jié)構(gòu)緊湊、效率較高、傳遞運(yùn)動(dòng)準(zhǔn)確可靠、使用維護(hù)簡(jiǎn)單,并可成批生產(chǎn),故在現(xiàn)代機(jī)措中應(yīng)用很廣。
減速器類(lèi)型很多,按傳動(dòng)級(jí)數(shù)主要分為:?jiǎn)渭?jí)、二級(jí)、多級(jí);按傳動(dòng)件類(lèi)型又可分為:齒輪、蝸桿、齒輪-蝸桿、蝸桿-齒輪等。
絕大多數(shù)減速器的箱體是用中等強(qiáng)度的鑄鐵鑄成,重型減速器用高強(qiáng)度鑄鐵或鑄鋼。少量生產(chǎn)時(shí)也可以用焊接箱體。鑄造或焊接箱體都應(yīng)進(jìn)行時(shí)效或退火處理。大量生產(chǎn)小型減速器時(shí)有可能采用板材沖壓箱體。減速器箱體的外形目前比較傾向于形狀簡(jiǎn)單和表面平整。箱體應(yīng)具有足夠的剛度,以免受載后變形過(guò)大而影響傳動(dòng)質(zhì)量。箱體通常由箱座和箱蓋兩部分所組成,其剖分面則通過(guò)傳動(dòng)的軸線。為了卸蓋容易,在剖分面處的一個(gè)凸緣上攻有螺紋孔,以便擰進(jìn)螺釘時(shí)能將蓋頂起來(lái)。聯(lián)接箱座和箱蓋的螺栓應(yīng)合理布置,并注意留出扳手空間。在軸承附近的螺栓宜稍大些并盡量靠近軸承。為保證箱座和箱蓋位置的準(zhǔn)確性,在剖分面的凸緣上應(yīng)設(shè)有2—3個(gè)圓錐定位銷(xiāo)。在箱蓋上備有為觀察傳動(dòng)嚙合情況用的視孔、為排出箱內(nèi)熱空氣用的通氣孔和為提取箱蓋用的起重吊鉤。在箱座上則常設(shè)有為提取整個(gè)減速器用的起重吊鉤和為觀察或測(cè)量油面高度用的油面指示器或測(cè)油孔。關(guān)于箱體的壁厚、肋厚、凸緣厚、螺栓尺寸等均可根據(jù)經(jīng)驗(yàn)公式計(jì)算,見(jiàn)有關(guān)圖冊(cè)。關(guān)于視孔、通氣孔和通氣器、起重吊鉤、油面指示Oe等均可從有關(guān)的設(shè)計(jì)手冊(cè)和圖冊(cè)中查出。在減速器中廣泛采用滾動(dòng)軸承。只有在載荷很大、工作條件繁重和轉(zhuǎn)速很高的減速器才采用滑動(dòng)軸承。
下面列舉兩種聯(lián)體式減速器的新型結(jié)構(gòu),圖中未將電動(dòng)機(jī)部分畫(huà)出。
1)齒輪—蝸桿二級(jí)減速器;2)圓柱齒輪—圓錐齒輪—圓柱齒輪三級(jí)減速器。
這些減速器都具有以下結(jié)構(gòu)特點(diǎn):
——在箱體上不沿齒輪或蝸輪軸線開(kāi)設(shè)剖分面。為了便于傳動(dòng)零件的安裝,在適當(dāng)部位
有較大的開(kāi)孔。
——在輸入軸和輸出軸端不采用傳統(tǒng)的法蘭式端蓋,而改用機(jī)械密封圈;在盲孔端則裝有沖壓薄壁端蓋。
——輸出軸的尺寸加大了,鍵槽的開(kāi)法和傳統(tǒng)的規(guī)定不同,甚至跨越了軸肩,有利于充分發(fā)揮輪轂的作用。
和傳統(tǒng)的減速器相比,這些結(jié)構(gòu)上的改進(jìn),既可簡(jiǎn)化結(jié)構(gòu),減少零件數(shù)目,同時(shí)又改善了制造工藝性。但設(shè)計(jì)時(shí)要注意裝配的工藝性,要提高某些裝配零件的制造精度。
國(guó)外在先進(jìn)減速機(jī)的設(shè)計(jì)生產(chǎn)上已經(jīng)十分成熟,一些知名生產(chǎn)商已經(jīng)擁有一百余年的減速機(jī)生產(chǎn)經(jīng)驗(yàn),市場(chǎng)份額也十分可觀。比如西門(mén)子公司旗下FLENDER減速機(jī)是目前業(yè)內(nèi)最大減速機(jī)供應(yīng)商,在產(chǎn)品結(jié)構(gòu)設(shè)計(jì)、制造方面具有很高的造詣。
國(guó)外減速機(jī)在電力、食品、建筑、礦業(yè)、水利等諸多行業(yè)都有著廣泛的應(yīng)用,其制造生產(chǎn)標(biāo)準(zhǔn)相比國(guó)內(nèi)也更高,我國(guó)的硬齒面減速機(jī)標(biāo)準(zhǔn)也來(lái)源于西門(mén)子公司的生產(chǎn)標(biāo)準(zhǔn)。國(guó)內(nèi)減速機(jī)的發(fā)展歷史也有近40年,生產(chǎn)廠家數(shù)目眾多,形式也多樣,目前,國(guó)內(nèi)各類(lèi)通用減速器的標(biāo)準(zhǔn)系列已達(dá)數(shù)百個(gè),基本可滿足各行業(yè)對(duì)通用減速器的需求。但是與國(guó)外相比我國(guó)減速機(jī)水平仍然有較大差距,同國(guó)外外減速器行業(yè)存在的比較突出的問(wèn)題是,行業(yè)整體新產(chǎn)品開(kāi)發(fā)能力弱、工藝創(chuàng)新及管理水平低。
隨著近幾年國(guó)內(nèi)經(jīng)濟(jì)的快速發(fā)展,重型機(jī)械行業(yè)出口量的增多,作為一個(gè)重要基礎(chǔ)行業(yè)的減速器行業(yè)發(fā)展異常迅猛。減速器企業(yè)正向著產(chǎn)銷(xiāo)規(guī)模擴(kuò)大,加工能力和技術(shù)水平持續(xù)提高發(fā)展。未來(lái)減速器市場(chǎng)行業(yè)前景將一片大好。
在重型機(jī)械市場(chǎng)需求量增加的同時(shí),行業(yè)也在產(chǎn)品升級(jí)、兩化融合、節(jié)能減排方面開(kāi)展了卓有成效的工作。在產(chǎn)品升級(jí)方面,多年不變的老產(chǎn)品技術(shù)更新步伐在加快。橋門(mén)式起重機(jī)行業(yè)企業(yè)采用聯(lián)合或者獨(dú)立研發(fā)的方式,紛紛對(duì)老產(chǎn)品進(jìn)行革新,形成了行業(yè)產(chǎn)品升級(jí)的熱潮。北京起重運(yùn)輸機(jī)械研究院聯(lián)合眾多企業(yè)開(kāi)展了橋式起重機(jī)系列輕量化工作,目前取得了階段性進(jìn)展。行業(yè)積極引入變頻調(diào)速傳動(dòng)技術(shù)、遙控和信息化技術(shù),加快產(chǎn)品向高端技術(shù)的升級(jí)。業(yè)界開(kāi)發(fā)的起重機(jī)無(wú)齒輪箱變頻傳動(dòng)主提升裝置開(kāi)始在市場(chǎng)中試水。
國(guó)際市場(chǎng)對(duì)重型機(jī)械裝備和備件的需求還將增長(zhǎng)。隨著歐美國(guó)家經(jīng)濟(jì)的逐漸復(fù)蘇,重新確立實(shí)體經(jīng)濟(jì)在國(guó)家經(jīng)濟(jì)中的地位,以及發(fā)展中國(guó)家的基本建設(shè)需求,重型機(jī)械產(chǎn)品在國(guó)際市場(chǎng)上會(huì)有更大的發(fā)展空間。
參考文獻(xiàn):
[1] 張展.齒輪減速器現(xiàn)狀及發(fā)展趨勢(shì)[J].水利電力機(jī)械,2001,23(1):58-59.
[2] 王之櫟,王大康.機(jī)械設(shè)計(jì)綜合課程設(shè)計(jì)[M].北京:機(jī)械工業(yè)出版社,2007:115.
[3] 馬履中.機(jī)械原理與設(shè)計(jì)(下冊(cè))[M].北京:機(jī)械工業(yè)出版社,2009:136-164.
[4] 韓燕,王宏蓮.圓柱齒輪減速器的三維造型設(shè)計(jì)[J].機(jī)電產(chǎn)品開(kāi)發(fā)與創(chuàng)新,2011,111-112.
[5] 張鋒,古樂(lè).機(jī)械設(shè)計(jì)課程設(shè)計(jì)手冊(cè)[M].北京:高等教育出版社,2010:234-289.
[6] 萬(wàn)靜.實(shí)用機(jī)械制圖與設(shè)計(jì)手冊(cè)[M].北京:中國(guó)電力出版社,2010:253-290.
[7] 隋秀梅,張慶玲,郭佳萍.機(jī)械設(shè)計(jì)基礎(chǔ)[M].北京:北京理工大學(xué)出版社,2010:108-198.
[8] 于惠力.機(jī)械零部件設(shè)計(jì)禁忌[M].北京:機(jī)械工業(yè)出版社,2011:111-147.
[9] 石嵐,李純彬.機(jī)械基礎(chǔ)[M].上海:復(fù)旦大學(xué)出版社,2010:207-244.
[10] 張德珍.基于特征造型的三位圓柱齒輪減速器參數(shù)設(shè)計(jì)系統(tǒng)[D].青島:山東科技大學(xué),2006:3-7.
二、 畢業(yè)設(shè)計(jì)方案或畢業(yè)論文研究方案
主要內(nèi)容:
1、完成減速器的總體設(shè)計(jì)并對(duì)圓柱齒輪減速器各個(gè)零件參數(shù)進(jìn)行設(shè)計(jì)計(jì)算;
2、用SolidWorks等三維軟件對(duì)減速器各零件進(jìn)行三維建模并裝配;
3、查閱此減速器方面的書(shū)籍及論文;
4、整理收集的書(shū)籍及論文;
5、完成論文的編寫(xiě)和外文翻譯;
6、用AutoCAD繪制零件圖和裝配總圖。
研究方法:
進(jìn)行文獻(xiàn)查詢(xún),學(xué)習(xí)并掌握AutoCAD和solidwork軟件的使用,完成此同軸式減速器的設(shè)計(jì),并進(jìn)行相關(guān)的計(jì)算。
研究思路:
查閱資料——學(xué)習(xí)并掌握兩種軟件的使用方法——根據(jù)實(shí)際工作需要進(jìn)行設(shè)計(jì)計(jì)算——兩種軟件的使用——減速器中各零件的三維建模、裝配以及零件圖和裝配圖的繪制。
三、 畢業(yè)設(shè)計(jì)(論文)預(yù)期成果及創(chuàng)新
整個(gè)畢業(yè)設(shè)計(jì)過(guò)程中,我們得到一篇畢業(yè)論文以及同軸式三級(jí)減速器的零件圖和裝配圖并且得到了三維建模的零件以及裝配總圖。我們能對(duì)減速器的結(jié)構(gòu)已經(jīng)機(jī)械傳動(dòng)系統(tǒng)有更加深入的了解,通過(guò)計(jì)算以及建模仿真能夠發(fā)現(xiàn)更好的減速器零件的設(shè)計(jì)方法
。
注:此表中的一、二、三項(xiàng),由學(xué)生在教師的指導(dǎo)下填寫(xiě)。
GEAR?AND?SHAFT?INTRODUCTION
Abstract:?The?important?position?of?the?wheel?gear?and?shaft?can't?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?thecase?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?toot.?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?helical?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?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?thoseof?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?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?in?ertias?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?atemperature?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?eath?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?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.?
Introduciton?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?majorityof?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?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?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
the?tool,?workpiece?and?chip.?A?typical?set?of?isotherms?is?shown?in?figure?where?it?can?be?seen?that,?as?could?be?expected,?there?is?a?very?large?temperature?gradient?throughout?the?width?of?the?chip?as?the?workpiece?material?is?sheared?in?primary?deformation?and?there?is?a?further?large?temperature?in?the?chip?adjacent?to?the?face?as?the?chip?is?sheared?in?secondary?deformation.?This?leads?to?a?maximum?cutting?temperature?a?short?distance?up?the?face?from?the?cutting?edge?and?a?small?distance?into?the?chip.?
Since?virtually?all?the?work?done?in?metal?cutting?is?converted?into?heat,?it?could?be?expected?that?factors?which?increase?the?power?consumed?per?unit?volume?of?metal?removed?will?increase?the?cutting?temperature.?Thus?an?increase?in?the?rake?angle,?all?other?parameters?remaining?constant,?will?reduce?the?power?per?unit?volume?of?metal?removed?and?cutting?temperatures?will?reduce.?When?considering?increase?in?undeformed?chip?thickness?and?cutting?speed?the?situation?is?more?comples.?An?increase?in?undeformed?chip?thickness?and?cutting?speed?the?situation?is?more?complex.?An?increase?in?undeformed?chip?thickness?tends?to?be?a?scale?effect?where?the?amounts?of?heat?which?pass?to?the?workpiece,?the?tool?and?chip?remain?in?fixed?proportions?and?the?changes?in?cutting?temperature?tend?to?be?small.?Increase?in?cutting?speed,?however,?reduce?the?amount?of?heat?which?passes?into?the?workpiece?and?this?increase?the?temperature?rise?of?the?chip?in?primary?deformation.?Further,?the?secondary?deformation?zone?tends?to?be?smaller?and?this?has?the?effect?of?increasing?the?temperatures?in?this?zone.?Other?changes?in?cutting?parameters?have?virtually?no?effect?on?the?power?consumed?per?unit?volume?of?metal?removed?and?consequently?have?virtually?no?effect?on?the?power?consumed?per?unit?volume?of?metal?removed?and?consequently?have?virtually?no?effect?on?the?cutting?temperatures.?Since?it?has?been?shown?that?even?small?changes?in?cutting?temperature?have?a?significant?effect?on?tool?wear?rate,?it?is?appropriate?to?indicate?how?cutting?temperatures?can?be?assessed?from?cutting?data.??
The?most?direct?and?accurate?method?for?measuring?temperatures?in?high-speed-steel?cutting?tools?is?that?of?Wright&Trent?which?also?yields?detailed?information?on?temperature?distributions?in?high-speed-steel?tools?which?relates?microstructural?changes?
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