【正文】 。設(shè)計(jì)人員必須在這樣的領(lǐng)域，如靜力學(xué)、運(yùn)動(dòng)學(xué)、動(dòng)力學(xué)和材料力學(xué)具有良好的素養(yǎng)，此外，還必須熟悉制造材料和制造工藝。任何產(chǎn)品設(shè)計(jì)的第一步工作之一是選擇用于制造每個(gè)部件的材料。在選擇時(shí)，產(chǎn)品的功能、外觀、材料成本和制造成本都很重要。,而是由十各種原因被存起來。當(dāng)需要類似的設(shè)計(jì)時(shí)，過去的記錄會(huì)有極大的幫助。一個(gè)小數(shù)點(diǎn)放錯(cuò)位置可以毀掉一個(gè)本來可以接受的項(xiàng)目。必須檢查再檢查設(shè)計(jì)工作的方方面面?；谟?jì)算機(jī)性能的交互系統(tǒng)使計(jì)算機(jī)輔助設(shè)計(jì)（CAD）和計(jì)算機(jī)輔助制造（CAM)成為可能。實(shí)驗(yàn)室測試、模型和樣機(jī)對于機(jī)械設(shè)計(jì)很有幫助。每天都會(huì)出現(xiàn)新材料和生產(chǎn)方法。一個(gè)好的設(shè)計(jì)人員應(yīng)經(jīng)常閱讀技術(shù)期刊以跟上新的發(fā)展工程工差固體由其表面邊界確定界限。實(shí)際上由于表面不規(guī)則以及固有的表面粗糙度，各個(gè)零件不能重復(fù)地做成公稱尺寸必須允許尺寸有一些變化以確保能夠制造。單個(gè)零件所允許的變化稱為公差。例如，一個(gè)給定型號(hào)的內(nèi)燃機(jī)的功率每臺(tái)都有所變化。設(shè)計(jì)人員的工作之一就是給一個(gè)零件指定尺寸和允許的變化，這個(gè)值能夠產(chǎn)生可以接受的性能。對于加工尺寸，通用公差可能是177。其他通用公差可以適用于如角度、鉆孔和沖孔，鑄件、鍛件、焊縫和焊角等情形。典型的公差被指定為英武成JSO標(biāo)準(zhǔn)所定義的幅度。下面這段將給出關(guān)于裝入孔內(nèi)的軸或柱形配合的具體例子。再者，滑動(dòng)軸承的直徑必須大于軸的直徑以使其旋轉(zhuǎn)。但是，變化的范圍不應(yīng)太大以免裝配時(shí)受損為了不至于有無窮無盡的被指定的公差尺寸，已經(jīng)制定了國家和國際標(biāo)準(zhǔn)確定了公差帶，比如hll/cll。通常使用的是基孔制，因?yàn)檫@會(huì)使公司內(nèi)部所需的鉆頭、絞刀、拉刀和計(jì)量工具種類的減少。實(shí)際尺寸：通過測量得到的部件尺寸。最大尺寸極限：兩個(gè)尺寸極限中較大的。上偏差：最大尺寸極限與其對應(yīng)的基本尺寸的代數(shù)差下偏差：最小尺寸極限與其對應(yīng)的基本尺寸的代數(shù)差公差：最大尺寸極限與最小尺寸極限的差值。初步設(shè)計(jì)產(chǎn)生滿足指定需求的解決方案。Ion和Smith把初步設(shè)計(jì)描述為由一系列形成和評(píng)估階段組成的一個(gè)反復(fù)的過程，各階段合在一起形成好的解決方案。產(chǎn)生盡可能多的或經(jīng)濟(jì)便利的構(gòu)思和想法是重要的。應(yīng)該抵抗這種誘惑，因?yàn)檫@樣結(jié)果總會(huì)更好些。產(chǎn)生了想法和構(gòu)思后，下一步就是對它們進(jìn)行評(píng)估并選擇最佳構(gòu)思．一種評(píng)估方法是使用列表矩陣。如果合適，準(zhǔn)則的重要性可以加權(quán)，最適合的構(gòu)思會(huì)具有最高總分。產(chǎn)生了初步的解決方案，下一步就是表達(dá)它們，以便它們能與所有涉及總體設(shè)計(jì)過程的人交流實(shí)際上，這一步可以采用繪制草圖或三維模型的形式，既可是物理模型也可是計(jì)算機(jī)生成的模型。Mechanical DesignAbstract: A machine is a bination of mechanisms and other ponents which transforms, transmits, or utilizes energy, force, or motion for a useful purpose. 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, from hub caps and filing cabinets to instruments and nuclear pressure vessels. The term mechanical design is used in a broader sense than machine design to include their design. For some apparatus, the thermal and fluid aspects that determine the requirements of heat, flow path, and volume are separately considered. However, 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 Designmechanisms Design Process ToleranceDesign processThe design begins from real of or the demand of existing instrument may need to take in to improve on the enduring, efficiency, weight, speed or the need new instrument to plete before function done by person, such as Assemble or target is all or partly after making sure, design of the next move is to conceive outline the organization that can plete the function needed and it arranges for this, drawing grass diagram to be worth barehanded biggest, it isn39。s satisfaction and manufacturing costs to all have something to do with design, the success which designs ability and engineering investment is closely related.Some design standardsAt this part, someone suggests the attitude of the usage creation carries on of analysis, this kind of analysis can cause a graveness improvement and to back up the product conceive outline with perfect, perhaps the product function is more, more economic and more the stage39。t only the right answer of[with] problem that can be from the numeral put forward wanting him to resolve only, not only only is give should dint value, the size works to limit can put forward more extensive views, for the purpose of improvement norm or in the analysis the front or the analysis the process, he will acquaint with to equip and its work condition, he is fully placed in a beneficial position which conceives outline to choose a he can put forward a suggestion change shape to Elimination moment of force or should dint concentration, not allow to set up to have to cut the organization that noodles and excessive dynamic state carry a lotus greatly best is he discards his meticulous of design but is not see a machine discard afterwards.For stiring up to create sex thinking, the suggestion designs a personnel and analytical the personnel use following ex standards are particularly applicable to an analysis personnel, although he may involve to all this 10. the physical function that sex land utilization need when using bine the control don39。And, can acquire an experience document from pute past needing the design for ising similar to, the past record will have a tremendous help.The check of puting(with diagram top size) is the most decimal point39。s don39。t make into Mr. to call size39。t certainly too big with as for make to assemble the function of the piece to bee the variety allowed by spare parts is called business trip.Business trip this technical term not only is applicable to from the acceptable scope of the parts size of[with] manufacturing craft creation, but also is applicable to a machine or processes of example, a give already set number of thepower each pedestals of . engine have , we usually discover this kind of variety model will be a frequency to distribute curve, for example distributes.(call the Gauss distribute again)One of the work which designs a personnel is the variety which specifies size for a spare parts and allows, this value canproduce acceptable function.Spare parts business tripWhen there is no appointed accurate size in the diagram, most organizations all have in general use business trip of being applicable to the process size, in general use business trip39。 is being specified to millimeter scopes of sizes can be of in general use business trips can be applicable to such as the angle and drill a hole with blunt bore, The casting, the forging, the welded joint and weld the angle） etc. situation.Can make reference to the diagram of past or general engineering to practice while giving the appointed business trip of a spare business trip of typical model39。t bee the accurate size to the parts manufacturing from the economy, all of the variety of stalk and bore size have to make , variety of scope should