機(jī)械式俯采采煤機(jī)設(shè)計(jì)【薄煤層采煤機(jī)的機(jī)械結(jié)構(gòu)設(shè)計(jì)】
機(jī)械式俯采采煤機(jī)設(shè)計(jì)【薄煤層采煤機(jī)的機(jī)械結(jié)構(gòu)設(shè)計(jì)】,薄煤層采煤機(jī)的機(jī)械結(jié)構(gòu)設(shè)計(jì),機(jī)械式俯采采煤機(jī)設(shè)計(jì)【薄煤層采煤機(jī)的機(jī)械結(jié)構(gòu)設(shè)計(jì)】,機(jī)械式,采煤,設(shè)計(jì),煤層,機(jī)械,結(jié)構(gòu)設(shè)計(jì)
湖 南 科 技 大 學(xué)
英文文獻(xiàn)翻譯
學(xué) 生 姓 名:
學(xué) 院: 機(jī)電工程學(xué)院
專業(yè)及班級: 機(jī)械設(shè)計(jì)制造及其自動化一班
學(xué) 號:
指導(dǎo)教師:
2015 年 5 月 28日
摘要
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機(jī)器是由機(jī)械裝置和其它組件組成的。它是一種用來轉(zhuǎn)換或傳遞能量的裝置,例如:發(fā)動機(jī)、渦輪機(jī)、車輛、起重機(jī)、印刷機(jī)、洗衣機(jī)、照相機(jī)和攝影機(jī)等。許多原則和設(shè)計(jì)方法不但適用于機(jī)器的設(shè)計(jì),也適用于非機(jī)器的設(shè)計(jì)。術(shù)語中的“機(jī)械裝置設(shè)計(jì)”?的含義要比“機(jī)械設(shè)計(jì)”的含義更為廣泛一些,機(jī)械裝置設(shè)計(jì)包括機(jī)械設(shè)計(jì)。在分析運(yùn)動及設(shè)計(jì)結(jié)構(gòu)時(shí),要把產(chǎn)品外型以及以后的保養(yǎng)也要考慮在機(jī)械設(shè)計(jì)中。在機(jī)械工程領(lǐng)域中,以及其它工程領(lǐng)域中,所有這些都需要機(jī)械設(shè)備,比如:開關(guān)、凸輪、閥門、船舶以及攪拌機(jī)等。
關(guān)鍵詞:設(shè)計(jì)流程、設(shè)計(jì)規(guī)則、機(jī)械設(shè)計(jì)
設(shè)計(jì)流程
設(shè)計(jì)開始之前就要想到機(jī)器的實(shí)際性,現(xiàn)存的機(jī)器需要在耐用性、效率、重量、速度,或者成本上得到改善。新的機(jī)器必需具有以前機(jī)器所能執(zhí)行的功能。
在設(shè)計(jì)的初始階段,應(yīng)該允許設(shè)計(jì)人員充分發(fā)揮創(chuàng)造性,不要受到任何約束。即使產(chǎn)生了許多不切實(shí)際的想法,也會在設(shè)計(jì)的早期,即在繪制圖紙之前被改正掉。只有這樣,才不致于阻斷創(chuàng)新的思路。通常,還要提出幾套設(shè)計(jì)方案,然后加以比較。很有可能在這個(gè)計(jì)劃最后決定中,使用了某些不在計(jì)劃之內(nèi)的一些設(shè)想。
一般的當(dāng)外型特點(diǎn)和組件部分的尺寸特點(diǎn)分析得透徹時(shí),就可以全面的設(shè)計(jì)和分析。接著還要客觀的分析機(jī)器性能的優(yōu)越性,以及它的安全、重量、耐用性,并且競爭力的成本也要考慮在分析結(jié)果之內(nèi)。每一個(gè)至關(guān)重要的部分要優(yōu)化它的比例和尺寸,同時(shí)也要保持與其它組成部分相協(xié)調(diào)。也要選擇原材料和處理原材料的方法。通過力學(xué)原理來分析和實(shí)現(xiàn)這些重要的特性,如那些靜態(tài)反應(yīng)的能量和摩擦力的最佳利用,像動力慣性、加速動力和能量;包括彈性材料的強(qiáng)度、應(yīng)力和剛度等材料的物理特性,以及流體潤滑和驅(qū)動器的流體力學(xué)。設(shè)計(jì)的過程是重復(fù)和合作的過程,無論是正式或非正式的進(jìn)行,對設(shè)計(jì)者來說每個(gè)階段都很重要。
最后,以圖樣為設(shè)計(jì)的標(biāo)準(zhǔn),并建立將來的模型。如果它的測試是符合事先要求的,則再將對初步設(shè)計(jì)進(jìn)行某些修改,使它能夠在制造成本上有所降低。產(chǎn)品的設(shè)計(jì)需要不斷探索和發(fā)展。許多方案必須被研究、試驗(yàn)、完善,然后決定使用還是放棄。雖然每個(gè)工程學(xué)問題的內(nèi)容是獨(dú)特的,但是設(shè)計(jì)師可以按照類似的步驟來解決問題。
產(chǎn)品的責(zé)任訴訟迫使設(shè)計(jì)人員和公司在選擇材料時(shí),采用最好的程序。在材料過程中,五個(gè)最常見的問題為:(a)不了解或者不會使用關(guān)于材料應(yīng)用方面的最新最好的信息資料;(b)未能預(yù)見和考慮材料的合理用途(如有可能,設(shè)計(jì)人員還應(yīng)進(jìn)一步預(yù)測和考慮由于產(chǎn)品使用方法不當(dāng)造成的后果。在近年來的許多產(chǎn)品責(zé)任訴訟案件中,由于錯誤地使用產(chǎn)品而受到傷害的原告控告生產(chǎn)廠家,并且贏得判決);(c)所使用的材料的數(shù)據(jù)不全或是有些數(shù)據(jù)不確定,尤其是當(dāng)其性能數(shù)據(jù)長期不更新;(d)質(zhì)量控制方法不適當(dāng)和未經(jīng)驗(yàn)證;(e)由一些完全不稱職的人員選擇材料。
通過對上述五個(gè)問題的分析,可以得出這些問題是沒有充分理由而存在的結(jié)論。對這些問題的研究分析可以為避免這些問題的出現(xiàn)而指明方向。盡管采用最好的材料選擇方法也不能避免發(fā)生產(chǎn)品責(zé)任訴訟,設(shè)計(jì)人員和工業(yè)界按照適當(dāng)?shù)某绦蜻M(jìn)行材料選擇,可以大大減少訴訟的數(shù)量。
從以上的討論可以看出,選擇材料的人們應(yīng)該對材料的性質(zhì),特點(diǎn)和加工方法有一個(gè)全面而基本的了解。在隨后生產(chǎn)和售后服務(wù)的幾年中,要接受新觀念的變化,或者由試驗(yàn)和經(jīng)驗(yàn)為基礎(chǔ),進(jìn)一步分析并改進(jìn)。
一些設(shè)計(jì)規(guī)則
在本節(jié)中,建議要運(yùn)用創(chuàng)造性的態(tài)度來替代和改進(jìn)。也許會創(chuàng)造出更實(shí)用、更經(jīng)濟(jì)、更耐用的產(chǎn)品。為了激發(fā)創(chuàng)造性思維,下列是設(shè)計(jì)和分析的建議規(guī)則。前六個(gè)規(guī)則對設(shè)計(jì)者來說特別適用。
? 1.要有創(chuàng)造性的利用所需要的物理性質(zhì)和控制過程。
?2.認(rèn)識負(fù)載產(chǎn)生的影響及其意義。
? 3.預(yù)測沒有想到的負(fù)載。
? 4.創(chuàng)造出對載荷更為有利的條件。
5.提供良好的應(yīng)力分布和最小的剛度條件。
?6.運(yùn)用最簡單的方程來優(yōu)化體積和面積。
? 7.選擇組合材料。
? 8.仔細(xì)選擇所備的原料和不可缺少的組件。
? 9.調(diào)整有效的設(shè)計(jì)方案,以適應(yīng)生產(chǎn)過程和降低成本。
10.規(guī)定好準(zhǔn)確的位置條件為了使組件安裝時(shí)不干涉。??
機(jī)械設(shè)計(jì)
一臺完整機(jī)器的設(shè)計(jì)是一個(gè)復(fù)雜的過程。機(jī)械設(shè)計(jì)是一項(xiàng)創(chuàng)造性的工作。設(shè)計(jì)工程師不僅在工作上要有創(chuàng)造性,還必須在機(jī)械制圖、運(yùn)動學(xué)、工程材料、材料力學(xué)和機(jī)械制造工藝學(xué)等方面具有深厚的基礎(chǔ)知識。任何產(chǎn)品在設(shè)計(jì)時(shí)第一步就是選擇產(chǎn)品每個(gè)部分的構(gòu)成材料。許多的材料被今天的設(shè)計(jì)師所使用。對產(chǎn)品的功能,它的外觀、材料的成本、制造的成本作出必要的選擇是十分重要的。對材料的特性必須事先作出仔細(xì)的評估。仔細(xì)精確的計(jì)算是必要的,以確保設(shè)計(jì)的有效性。在任何失敗的情況下,最好知道在最初設(shè)計(jì)中有有缺陷的部件。計(jì)算(圖紙尺寸)檢查是非常重要的。一個(gè)小數(shù)點(diǎn)的位置放錯,就可以導(dǎo)致一個(gè)本可以完成的項(xiàng)目失敗。設(shè)計(jì)工作的各個(gè)方面都應(yīng)該檢查和復(fù)查。
計(jì)算機(jī)是一種工具,它能夠幫助機(jī)械設(shè)計(jì)師減輕繁瑣的計(jì)算,并對現(xiàn)有數(shù)據(jù)提供進(jìn)一步的分析?;酉到y(tǒng)基于計(jì)算機(jī)的能力,已經(jīng)使計(jì)算機(jī)輔助設(shè)計(jì)(CAD)和計(jì)算機(jī)輔助制造(CAM)成為了可能。心理學(xué)家經(jīng)常談?wù)撊绾问谷藗冞m應(yīng)他們所操作的機(jī)器。設(shè)計(jì)人員的基本職責(zé)是努力使機(jī)器來適應(yīng)人們。這并不是一項(xiàng)容易的工作,因?yàn)閷?shí)際上并不存在著一個(gè)對所有人來說都是最優(yōu)的操作范圍和操作過程。另一個(gè)重要問題,設(shè)計(jì)工程師必須能夠同其他有關(guān)人員進(jìn)行交流和磋商。在開始階段,設(shè)計(jì)人員必須就初步設(shè)計(jì)同管理人員進(jìn)行交流和磋商,并得到批準(zhǔn)。這一般是通過口頭討論,草圖和文字材料進(jìn)行的。
如前所訴,機(jī)械設(shè)計(jì)的目的是生產(chǎn)能夠滿足人類需求的產(chǎn)品。發(fā)明、發(fā)現(xiàn)和科技知識本身并不一定能給人類帶來好處,只有當(dāng)它們被應(yīng)用在產(chǎn)品上才能產(chǎn)生效益。因而,應(yīng)該認(rèn)識到在一個(gè)特定的產(chǎn)品進(jìn)行設(shè)計(jì)之前,必須先確定人們是否需要這種產(chǎn)品。
應(yīng)當(dāng)把機(jī)械設(shè)計(jì)看成是機(jī)械設(shè)計(jì)人員運(yùn)用創(chuàng)造性的才能進(jìn)行產(chǎn)品設(shè)計(jì)、系統(tǒng)分析和制定產(chǎn)品的制造工藝學(xué)的一個(gè)良機(jī)。掌握工程基礎(chǔ)知識要比熟記一些數(shù)據(jù)和公式更為重要。僅僅使用數(shù)據(jù)和公式是不足以在一個(gè)好的設(shè)計(jì)中做出所需的全部決定的。另一方面,應(yīng)該認(rèn)真精確的進(jìn)行所有運(yùn)算。例如,即使將一個(gè)小數(shù)點(diǎn)的位置放錯,也會使正確的設(shè)計(jì)變成錯誤的。
一個(gè)好的設(shè)計(jì)人員應(yīng)該勇于提出新的想法,而且愿意承擔(dān)一定的風(fēng)險(xiǎn),當(dāng)新的方法不適用時(shí),就使用原來的方法。因此,設(shè)計(jì)人員必須要有耐心,因?yàn)樗ǖ臅r(shí)間和努力并不能保證帶來成功。一個(gè)全新的設(shè)計(jì),要求屏棄許多陳舊的,為人們所熟知的方法。由于許多人墨守成規(guī),這樣做并不是一件容易的事。一位機(jī)械設(shè)計(jì)師應(yīng)該不斷地探索改進(jìn)現(xiàn)有的產(chǎn)品的方法,在此過程中應(yīng)該認(rèn)真選擇原有的、經(jīng)過驗(yàn)證的設(shè)計(jì)原理,將其與未經(jīng)過驗(yàn)證的新觀念結(jié)合起來。
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Abstract
A?machine?is?a?combination?of?mechanisms?and?other?components?which?transforms,?transmits.?Examples?are?engines,?turbines,?vehicles,?hoists,?printing?presses,?washing?machines,?and?movie?cameras.?Many?of?the?principles?and? methods?of?design?that?apply?to?machines?also?apply?to?manufactured?articles?that?are?not?true?machines.?The?term?"mechanical?design"?is?used?in?a?broader?sense?than?"machine?design"?to?include?their?design.?the?motion?and?structural?aspects?and?the?provisions?for?retention?and?enclosure?are?considerations?in?mechanical?design.?Applications?occur?in?the?field?of?mechanical?engineering,?and?in?other?engineering?fields?as?well,?all?of?which?require?mechanical?devices,?such?as?switches,?cams,?valves,?vessels,?and?mixers.?
Keywords:?Mechanical?Design?mechanisms?Design?Process?? The?Design?Process?
Designing?starts?with?a?need?real.Existing?apparatus?may?need?improvements?in?durability,?efficiency,?weight,?speed,?or?cost.?New?apparatus?may?be?needed?to?perform?a?function?previously?
One?by?men,?such?as?computation,?assembly,?or?servicing.?With?the?objective?wholly?or?partly?In?the?design?preliminary?stage,?should?allow?to?design?the?personnel?fully?to?display?the?creativity,?not?each?kind?of?restraint.?Even?if?has?had?many?impractical?ideas,?also?can?in?the?design?early?time,?namely?in?front?of?the?plan?blueprint?is?corrected.?Only?then,?only?then?does?not?send?to?stops?up?the?innovation?the?mentality.?Usually,?must?propose?several?sets?of?design?proposals,?then?perform?the?comparison.?Has?the?possibility?very?much?in?the?plan?which?finally?designated,?has?used?certain?not?in?plan?some?ideas?which?accepts.?
When?the?general?shape?and?a?few?dimensions?of?the?several?components?become?apparent,?analysis?can?begin?in?earnest.?The?analysis?will?have?as?its?objective?satisfactory?or?superior?performance,?plus?safety?and?durability?with?minimum?weight,?and?a?competitive?cost.?Optimum?proportions?and?dimensions?will?be?sought?for?each?critically?loaded?section,?together?with?a?balance?between?the?strengths?of?the?several?components.?Materials?and?their?treatment?will?be?chosen.?These?important?objectives?can?be?attained?only?by?analysis?based?upon?the?principles?of?mechanics,?such?as?those?of?static?for?reaction?forces?and?for?the?optimum?utilization?of?friction;?of?dynamics?for?inertia,?acceleration,?and?energy;?of?elasticity?and?strength?of?materials?for?stress?and?deflection;?of?physical?behavior?of?materials;?and?of?fluid?mechanics?for?lubrication?and?hydrodynamic?drives.?The?analyses?may?be?made?by?the?same?engineer?who?conceived?the?arrangement?of?mechanisms,?or,?in?a?large?company,?they?may?be?made?by?a?separate?analysis?division?or?research?group.?
Design?is?a?reiterative?and?cooperative?process,?whether?done?formally?or?informally,?and?the?analyst?can?contribute?to?phases?other?than?his?own.?Product?design?requires?much?research?and?development.?Many?Concepts?of?an?idea?must?be?studied,?tried,?and?then?either?used?or?discarded.?Although?the?content?of?each?engineering?problem?is?unique,?the?designers?follow?the?similar?process?to?solve?the?problems.??
?Product?liability?suits?designers?and?forced?in?material?selection,?using?the?best?program.?In?the?process?of?material,?the?most?common?problems?for?five?(a)?don't?understand?or?not?use?about?the?latest?application?materials?to?the?best? information,?(b)?failed?to?foresee?and?consider?the?reasonable?use?material?may?(such?as?possible,?designers?should?further?forecast?and?consider?due?to?improper?use?products.?In?recent?years,?many?products?liability?in?litigation,?the?use?of? products?and?hurt?the?plaintiff?accused?manufacturer,?and?won?the?decision),?(c)?of?the?materials?used?all?or?some?of?the?data,?data,?especially?when?the?uncertainty?long-term?performance?data?is?so,?(d)?quality?control?method?is?not?suitable?and?unproven,?(e)?by?some?completely?incompetent?persons?choose?materials.?
Through?to?the?above?five?questions?analysis,?may?obtain?these?questions?is?does?not?have?the?sufficient?reason?existence?the?conclusion.?May?for?avoid?these?questions?to?these?questions?research?analyses?the?appearance?indicating?the?direction.?Although?uses?the?best?choice?of?material?method?not?to?be?able?to?avoid?having?the?product?responsibility?lawsuit,?designs?the?personnel?and?the?industry?carries?on?the?choice?of?material?according?to?the?suitable?procedure,?may?greatly?reduce?the?lawsuit?the?quantity.??
May?see?from?the?above?discussion,?the?choice?material?people?should?to?the?material?nature,?the?characteristic?and?the?processing?method?have?comprehensive?and?the?basic?understanding.? ?Finally,?a?design?based?upon?function,?and?a?prototype?may?be?built.?If?its?tests?are?satisfactory,?the?initial?design?will?undergo?certain?modifications?that?enable?it?to?be?manufactured?in?quantity?at?a?lower?cost.?During?subsequent?years?of?manufacture?and?service,?the?design?is?likely?to?undergo?changes?as?new?ideas?are?conceived?or?as?further?analyses?based?upon?tests?and?experience?indicate?alterations.?Sales?appeal.??
Some?Rules?for?Design?
In?this?section?it?is?suggested?that,?applied?with?a?creative?attitude,?analyses?can?lead?to?important?improvements?and?to?the?conception?and?perfection?of?alternate,?perhaps?more?functional,?economical,?and?durable?products.?? To?stimulate?creative?thought,?the?following?rules?are?suggested?for?the? designer?and?analyst.?The?first?six?rules?are?particularly?applicable?for?the?analyst.
?1.?A?creative?use?of?need?of?physical?properties?and?control?process.?
2. ?Recognize?functional?loads?and?their?significance.
3.?Anticipate?unintentional?loads.?
4.Devise?more?favorable?loading?conditions.?
5.?Provide?for?favorable?stress?distribution?and?stiffness?with?minimum?weight.
?6.?Use?basic?equations?to?proportion?and?optimize?dimensions.?
7. ?Choose?materials?for?a?combination?of?properties.?
8. ?Select?carefully,?stock?and?integral?components.?
9. ?Modify?a?functional?design?to?fit?the?manufacturing?process?and?reduce?cost.?
10. ?Provide?for?accurate?location?and?noninterference?of?parts?in?assembly.???
Machine?Design?
The?complete?design?of?a?machine?is?a?complex?process.?The?machine?design?is?a?creative?work.?Project?engineer?not?only?must?have?the?creativity?in?the?work,?but?also?must?in?aspect?and?so?on?mechanical?drawing,?kinematics,??material,?materials?mechanics?and?machine?manufacture?technology?has?the?deep?elementary?knowledge.? ?
One?of?the?first?steps?in?the?design?of?any?product?is?to?select?the?material?from?which?each?part?is?to?be?made.?Numerous?materials?are?available?to?today's?designers.?The?function?of?the?product,?its?appearance,?the?cost?of?the?material,?and?the?cost?of?fabrication?are?important?in?making?a?selection.?A?careful? evaluation?of?the?properties?of?a.?material?must?be?made?prior?to?any?calculations.
Careful?calculations?are?necessary?to?ensure?the?validity?of?a?design.?In?case?of?any?part?failures,?it?is?desirable?to?know?what?was?done?in?originally?designing?the?defective?components.?The?checking?of?calculations?
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