錘式破碎機(jī)機(jī)械結(jié)構(gòu)設(shè)計(jì)【含CAD圖紙+三維SW+文檔】
錘式破碎機(jī)機(jī)械結(jié)構(gòu)設(shè)計(jì)【含CAD圖紙+三維SW+文檔】,含CAD圖紙+三維SW+文檔,破碎,機(jī)械,結(jié)構(gòu)設(shè)計(jì),CAD,圖紙,三維,SW,文檔
任 務(wù) 書
1．畢業(yè)設(shè)計(jì)的背景：
在各工業(yè)部門，每年都有大量的原料和再利用的廢料都需要用破碎機(jī)進(jìn)行加工處理，如在選礦廠，為使礦石中的有用礦物達(dá)到單體分離，就需要用破碎機(jī)將原礦破碎到磨礦工藝所要求的粒度。磨機(jī)再將破碎機(jī)提供的原料磨至有用礦物單體分離的粒度。再如在水泥廠，須將原料破碎，以便燒成熟料，然后在將熟料用磨機(jī)磨成水泥。物料進(jìn)入破碎機(jī)中，立即受到高速運(yùn)動(dòng)的錘頭的沖擊而粉碎，在物料破碎的整個(gè)過(guò)程中，物料之間也相互沖擊粉碎。
2．畢業(yè)設(shè)計(jì)(論文)的內(nèi)容和要求：
內(nèi)容：破碎機(jī)的破碎對(duì)象是：石灰石、煤塊、焦碳、石膏等軟物料；主要完成各參數(shù)設(shè)計(jì)計(jì)算，各主要結(jié)構(gòu)的設(shè)計(jì)計(jì)算，Pro/E三維建模，總裝配圖，主要零件的零件圖。
要求：1.學(xué)生應(yīng)具備機(jī)械設(shè)計(jì)制造方面的基礎(chǔ)知識(shí)和工程軟件AutoCAD、UG或Pro/E等的基本操作能力；
2.要求學(xué)習(xí)態(tài)度端正、責(zé)任心強(qiáng)，具有較強(qiáng)的文獻(xiàn)查詢、整理、消化能力。
3．主要參考文獻(xiàn)：
[1]朱里.機(jī)械原理[M].北京: 高等教育出版社, 2010.
[2]濮良貴.機(jī)械設(shè)計(jì)[M].北京:高等教育出版社, 2014.
[3]邢邦圣.機(jī)械制圖與計(jì)算機(jī)繪圖[M].北京:化學(xué)工業(yè)出版社, 2011.
[4]陳秀寧.機(jī)械設(shè)計(jì)課程設(shè)計(jì)[M].浙江:浙江大學(xué)出版社, 2012.
[5]機(jī)械設(shè)計(jì)手冊(cè)編委會(huì)．機(jī)械設(shè)計(jì)手冊(cè)（新版）[M]．北京：機(jī)械工業(yè)出版社，2004.
4．畢業(yè)設(shè)計(jì)(論文)進(jìn)度計(jì)劃(以周為單位)：
第1周 查閱資料、英文翻譯；
第2周 撰寫開題報(bào)告；
第3周 破碎機(jī)總體結(jié)構(gòu)設(shè)計(jì)；
第4周 各參數(shù)設(shè)計(jì)計(jì)算；
第5、6周 破碎機(jī)各部分零件結(jié)構(gòu)設(shè)計(jì)計(jì)算、強(qiáng)度計(jì)算；
第7周 部分零件零件圖繪制；
第8周 完成總裝配圖；
第9~11周 撰寫畢業(yè)設(shè)計(jì)說(shuō)明書初稿、查重；
第12周 修改畢業(yè)設(shè)計(jì)說(shuō)明書、定稿；
第13周 準(zhǔn)備答辯。
教研室審查意見：
教研室主任簽名： 年 月 日
學(xué)院審查意見：
教學(xué)院長(zhǎng)簽名： 年 月 日
開題報(bào)告
課題名稱
錘式破碎機(jī)機(jī)械結(jié)構(gòu)設(shè)計(jì)
課題來(lái)源
B.社會(huì)生產(chǎn)實(shí)踐
課題類型
工程設(shè)計(jì)類
1．選題的背景及意義：
在各工業(yè)部門，每年都有大量的原料和再利用的廢料都需要用破碎機(jī)進(jìn)行加工處理，如在選礦廠，為使礦石中的有用礦物達(dá)到單體分離，就需要用破碎機(jī)將原礦破碎到磨礦工藝所要求的粒度。磨機(jī)再將破碎機(jī)提供的原料磨至有用礦物單體分離的粒度。再如在水泥廠，須將原料破碎，以便燒成熟料，然后在將熟料用磨機(jī)磨成水泥。物料進(jìn)入破碎機(jī)中，立即受到高速運(yùn)動(dòng)的錘頭的沖擊而粉碎，在物料破碎的整個(gè)過(guò)程中，物料之間也相互沖擊粉碎。
對(duì)粗碎而言，目前還沒有研制出更新的設(shè)備以取代傳統(tǒng)的顎式破碎機(jī)和回旋式破碎機(jī)，主要是利用現(xiàn)代技術(shù)，予以改進(jìn)、完善和提高耐磨性，達(dá)到節(jié)能、高效、長(zhǎng)壽的目的。細(xì)碎方面新機(jī)型更多些。
2．研究?jī)?nèi)容擬解決的主要問題：
對(duì)錘式破碎機(jī)的結(jié)構(gòu)原理進(jìn)行了分析，結(jié)構(gòu)參數(shù)和工作參數(shù)的選擇與計(jì)算，借助計(jì)算機(jī)繪圖技術(shù)來(lái)完成結(jié)構(gòu)設(shè)計(jì)。通過(guò)這次畢業(yè)設(shè)計(jì)，可以系統(tǒng)地把大學(xué)里的專業(yè)知識(shí)復(fù)習(xí)鞏固后應(yīng)用到實(shí)際設(shè)計(jì)和生產(chǎn)中去，提高自己的動(dòng)手能力和創(chuàng)新能力，鍛煉自己的自主能力和查閱資料的能力，以此提高的綜合素質(zhì)來(lái)適應(yīng)社會(huì)發(fā)展的需求。
通過(guò)對(duì)錘式破碎機(jī)結(jié)構(gòu)的研究和設(shè)計(jì)，通過(guò)采用經(jīng)驗(yàn)公式對(duì)結(jié)構(gòu)參數(shù)進(jìn)行優(yōu)化設(shè)計(jì)。同時(shí)借助計(jì)算機(jī)繪圖軟件將破碎機(jī)各個(gè)部件和零件表示出來(lái)，使結(jié)構(gòu)更加的完善。本課題擬解決的主要問題：錘式破碎機(jī)總體設(shè)計(jì)及軸強(qiáng)度校核等計(jì)算、裝配圖、部分零件圖、三維建模、計(jì)算電動(dòng)機(jī)功率及選定電動(dòng)機(jī)、錘頭設(shè)計(jì)與計(jì)算、選擇使用的軸承、飛輪的設(shè)計(jì)與計(jì)算、箱體結(jié)構(gòu)設(shè)計(jì)。
3．研究方法技術(shù)路線：
1.在接到錘式破碎機(jī)機(jī)械結(jié)構(gòu)設(shè)計(jì)任務(wù)書后，首先要仔細(xì)閱讀，明確設(shè)計(jì)要求以及所給的各參數(shù)，在心中明確一個(gè)大致的設(shè)計(jì)思路。2.通過(guò)閱讀學(xué)習(xí)相關(guān)文獻(xiàn)資料，了解現(xiàn)有錘式破碎機(jī)的設(shè)計(jì)過(guò)程以及學(xué)習(xí)Pro/E，Solidworks，CAD建模繪圖。3.首先確定錘式破碎機(jī)整體傳動(dòng)方案，選擇電動(dòng)機(jī)，確定功率以及軸的力矩大小，然后進(jìn)行軸、錘頭的校核。最后設(shè)計(jì)殼體和箱蓋并且選用密封圈、軸承等標(biāo)準(zhǔn)件。4.三維軟件進(jìn)行三維建模和工程圖的繪制以及運(yùn)動(dòng)仿真。5.結(jié)合國(guó)內(nèi)外已有的錘式破碎機(jī)來(lái)優(yōu)化并完善自己的設(shè)計(jì)。
4．研究的總體安排和進(jìn)度計(jì)劃：
第1周 查閱資料、英文翻譯；
第2周 撰寫開題報(bào)告；
第3周 破碎機(jī)總體結(jié)構(gòu)設(shè)計(jì)；
第4周 各參數(shù)設(shè)計(jì)計(jì)算；
第5、6周 破碎機(jī)各部分零件結(jié)構(gòu)設(shè)計(jì)計(jì)算、強(qiáng)度計(jì)算；
第7周 部分零件零件圖繪制；
第8周 完成總裝配圖；
第9~11周 撰寫畢業(yè)設(shè)計(jì)說(shuō)明書初稿、查重；
第12周 修改畢業(yè)設(shè)計(jì)說(shuō)明書、定稿；
第13周 準(zhǔn)備答辯。
5．主要參考文獻(xiàn)：
[1]朱里.機(jī)械原理[M].北京: 高等教育出版社, 2010.
[2]濮良貴.機(jī)械設(shè)計(jì)[M].北京:高等教育出版社, 2014.
[3]邢邦圣.機(jī)械制圖與計(jì)算機(jī)繪圖[M].北京:化學(xué)工業(yè)出版社, 2011.
[4]陳秀寧.機(jī)械設(shè)計(jì)課程設(shè)計(jì)[M].浙江:浙江大學(xué)出版社, 2012.
[5]機(jī)械設(shè)計(jì)手冊(cè)編委會(huì)．機(jī)械設(shè)計(jì)手冊(cè)（新版）[M]．北京：機(jī)械工業(yè)出版社，2004.
[6]吳宗澤，羅圣國(guó).機(jī)械設(shè)計(jì)課程設(shè)計(jì)手冊(cè)[M].3版，北京：高等教育出版社，2006.
[7]陶冶.材料成形技術(shù)基礎(chǔ)[M].北京：機(jī)械工業(yè)出版社，2002.
[8]趙雪松，任小華，于華.機(jī)械制造裝備設(shè)計(jì)[M] .武漢：華中科技大學(xué)
出版社，2009.
[9]張顯偉，胡靜.Word綜合應(yīng)用[M].北京：清華大學(xué)出版社，2006.
[10]鄭鳴皋主編．破碎機(jī)綜述．北京：機(jī)械工業(yè)出版社，2001.
[11]范祖堯主編. 現(xiàn)代機(jī)械設(shè)備設(shè)計(jì)手冊(cè). 北京：機(jī)械工業(yè)出版社，1996.
[12]成大先.機(jī)械設(shè)計(jì)手冊(cè).北京：化學(xué)工業(yè)出版社，1993
[13]王昆、何小柏等編.課程設(shè)計(jì)[M].北京：高等教育出版社，2005.
[14]章浩,張西良,周士沖.機(jī)電一體化技術(shù)的發(fā)展與應(yīng)用[J].農(nóng)機(jī)化研究,2006(7).
[15]Shigley J E,Uicher J J.Theory of machines and mechanisms.New York:McGraw-Hill Book Company,1980.
[16]Dennis P. Nolan .Fire Fighting Pumping Systems at Industrial Facilities [J] .New Jersey, USA: Noyes publications, 1998.
[17]Garr M. Jones, Robert L. Sank, Bayard E. Baseman, George Tchobanoglous. Pumping station design [J] .Burlington. USA: Elsevier Inc,2008.
[18]William B. Rugh, Waterville, Ohio,Right angle drive gearbox [J] .Publication Date: 03/07/2000,1-6
指導(dǎo)教師意見：
對(duì)“文獻(xiàn)綜述”的評(píng)語(yǔ)：文獻(xiàn)查閱完整，兼顧中文與外文文獻(xiàn)，能夠滿足設(shè)計(jì)基本需求。
對(duì)總體安排和進(jìn)度計(jì)劃的評(píng)語(yǔ)：研究的總體安排和進(jìn)度計(jì)劃合理，同意開題。
指導(dǎo)教師簽名： 年 月 日
教研室意見：
通過(guò)，同意開題
教研室主任簽名： 年 月 日
學(xué)院意見：
教學(xué)院長(zhǎng)簽名： 年 月 日
外文翻譯
Friction Lubrication of Bearing
In many of the problem thus far , the student has been asked to disregard or neglect friction . Actually , friction is present to some degree whenever two parts are in contact and move on each other. The term friction refers to the resistance of two or more parts to movement.
Friction is harmful or valuable depending upon where it occurs. friction is necessary for fastening devices such as screws and rivets which depend upon friction to hold the fastener and the parts together. Belt drivers, brakes, and tires are additional applications where friction is necessary.
The friction of moving parts in a machine is harmful because it reduces the mechanical advantage of the device. The heat produced by friction is lost energy because no work takes place. Also , greater power is required to overcome the increased friction. Heat is destructive in that it causes expansion. Expansion may cause a bearing or sliding surface to fit tighter. If a great enough pressure builds up because made from low temperature materials may melt.
There are three types of friction which must be overcome in moving parts: (1)starting, (2)sliding, and(3)rolling. Starting friction is the friction between two solids that tend to resist movement. When two parts are at a state of rest, the surface irregularities of both parts tend to interlock and form a wedging action. To produce motion in these parts, the wedge-shaped peaks and valleys of the stationary surfaces must be made to slide out and over each other. The rougher the two surfaces, the greater is starting friction resulting from their movement .
Since there is usually no fixed pattern between the peaks and valleys of two mating parts, the irregularities do not interlock once the parts are in motion but slide over each other. The friction of the two surfaces is known as sliding friction. As shown in figure ,starting friction is always greater than sliding friction .
Rolling friction occurs when roller devces are subjected to tremendous stress which cause the parts to change shape or deform. Under these conditions, the material in front of a roller tends to pile up and forces the object to roll slightly uphill. This changing of shape , known as deformation, causes a movement of molecules. As a result ,heat is produced from the added energy required to keep the parts turning and overcome friction.
The friction caused by the wedging action of surface irregularities can be overcome partly by the precision machining of the surfaces. However, even these smooth surfaces may require the use of a substance between them to reduce the friction still more. This substance is usually a lubricant which provides a fine, thin oil film. The film keeps the surfaces apart and prevents the cohesive forces of the surfaces from coming in close contact and producing heat .
Another way to reduce friction is to use different materials for the bearing surfaces and rotating parts. This explains why bronze bearings, soft alloys, and copper and tin iolite bearings are used with both soft and hardened steel shaft. The iolite bearing is porous. Thus, when the bearing is dipped in oil, capillary action carries the oil through the spaces of the bearing. This type of bearing carries its own lubricant to the points where the pressures are the greatest.
Moving parts are lubricated to reduce friction, wear, and heat. The most commonly used lubricants are oils, greases, and graphite compounds. Each lubricant serves a different purpose. The conditions under which two moving surfaces are to work determine the type of lubricant to be used and the system selected for distributing the lubricant.
On slow moving parts with a minimum of pressure, an oil groove is usually sufficient to distribute the required quantity of lubricant to the surfaces moving on each other .
A second common method of lubrication is the splash system in which parts moving in a reservoir of lubricant pick up sufficient oil which is then distributed to all moving parts during each cycle. This system is used in the crankcase of lawn-mower engines to lubricate the crankshaft, connecting rod ,and parts of the piston.
A lubrication system commonly used in industrial plants is the pressure system. In this system, a pump on a machine carries the lubricant to all of the bearing surfaces at a constant rate and quantity.
There are numerous other systems of lubrication and a considerable number of lubricants available for any given set of operating conditions. Modern industry pays greater attention to the use of the proper lubricants than at previous time because of the increased speeds, pressures, and operating demands placed on equipment and devices.
Although one of the main purposes of lubrication is reduce friction, any substance-liquid , solid , or gaseous-capable of controlling friction and wear between sliding surfaces can be classed as a lubricant.
Varieties of lubrication
Unlubricated sliding. Metals that have been carefully treated to remove all foreign materials seize and weld to one another when slid together. In the absence of such a high degree of cleanliness, adsorbed gases, water vapor ,oxides, and contaminants reduce frictio9n and the tendency to seize but usually result in severe wear; this is called “unlubricated ”or dry sliding.
Fluid-film lubrication. Interposing a fluid film that completely separates the sliding surfaces results in fluid-film lubrication. The fluid may be introduced intentionally as the oil in the main bearing of an automobile, or unintentionally, as in the case of water between a smooth tuber tire and a wet pavement. Although the fluid is usually a liquid such as oil, water, and a wide range of other materials, it may also be a gas. The gas most commonly employed is air.
Boundary lubrication. A condition that lies between unlubricated sliding and fluid-film lubrication is referred to as boundary lubrication, also defined as that condition of lubrication in which the friction between surfaces is determined by the properties of the surfaces and properties of the lubricant other than viscosity. Boundary lubrication encompasses a significant portion of lubrication phenomena and commonly occurs during the starting and stopping off machines.
Solid lubrication. Solid such as graphite and molybdenum disulfide are widely used when normal lubricants do not possess sufficient resistance to load or temperature extremes. But lubricants need not take only such familiar forms as fats, powders, and gases; even some metals commonly serve as sliding surfaces in some sophisticated machines.
Function of lubricants
Although a lubricant primarily controls friction and ordinarily does perform numerous other functions, which vary with the application and usually are interrelated .
Friction control. The amount and character of the lubricant made available to sliding surfaces have a profound effect upon the friction that is encountered. For example, disregarding such related factors as heat and wear but considering friction alone between the same surfaces with on lubricant. Under fluid-film conditions, friction is encountered. In a great range of viscosities and thus can satisfy a broad spectrum of functional requirements. Under boundary lubrication conditions , the effect of viscosity on friction becomes less significant than the chemical nature of the lubricant.
Wear control. wear occurs on lubricated surfaces by abrasion, corrosion ,and solid-to-solid contact wear by providing a film that increases the distance between the sliding surfaces ,thereby lessening the damage by abrasive contaminants and surface asperities.
Temperature control. Lubricants assist in controlling corrosion of the surfaces themselves is twofold. When machinery is idle, the lubricant acts as a preservative. When machinery is in use, the lubricant controls corrosion by coating lubricated parts with a protective film that may contain additives to neutralize corrosive materials. The ability of a lubricant to control corrosion is directly relatly to the thickness of the lubricant film remaining on the metal surfaces and the chermical composition of the lubricant.
Other functions
Lubrication are frequently used for purposes other than the reduction of friction. Some of these applications are described below.
Power transmission. Lubricants are widely employed as hydraulic fluids in fluid transmission devices.
Insulation. In specialized applications such as transformers and switchgear , lubricants with high dielectric constants acts as electrical insulators. For maximum insulating properties, a lubricant must be kept free of contaminants and water.
Shock dampening. Lubricants act as shock-dampening fluids in energy transferring devices such as shock absorbers and around machine parts such as gears that are subjected to high intermittent loads.
Sealing. Lubricating grease frequently performs the special function of forming a seal to retain lubricants or to exclude contaminants.
The object of lubrication is to reduce friction ,wear , and heating of machine pars which move relative to each other. A lubricant is any substance which, when inserted between the moving surfaces, accomplishes these purposes. Most lubricants are liquids(such as mineral oil, silicone fluids, and water),but they may be solid for use in dry bearings, greases for use in rolling element bearing, or gases(such as air) for use in gas bearings. The physical and chemical interaction between the lubricant and lubricating surfaces must be understood in order to provide the machine elements with satisfactory life.
The understanding of boundary lubrication is normally attributed to hardy and doubleday , who found the extrememly thin films adhering to surfaces were often sufficient to assist relative sliding. They concluded that under such circumstances the chemical composition of fluid is important, and they introduced the term “boundary lubrication”. Boundary lubrication is at the opposite end of the spectrum from hydrodynamic lubrication.
Five distinct of forms of lubrication that may be defined :(a) hydrodynamic; (b)hydrostatic;(c)elastohydrodynamic (d)boundary; (e)solid film.
Hydrodynamic lubrication means that the load-carrying surfaces of the bearing are separated by a relatively thick film of lubricant, so as to prevent metal contact, and that the stability thus obtained can be explained by the laws of the lubricant under pressure ,though it may be; but it does require the existence of an adequate supply at all times. The film pressure is created by the moving surfaces itself pulling the lubricant under pressure, though it maybe. The film pressure is created by the moving surface to creat the pressure necessary to separate the surfaces against the load on the bearing . hydrodynamic lubrication is also called full film ,or fluid lubrication .
Hydrostatic lubrication is obtained by introducing the lubricant ,which is sometime air or water ,into the load-bearing area at a pressure high enough to separate the surface with a relatively thick film of lubricant. So ,unlike hydrodynanmic lubrication, motion of one surface relative to another is not required .
Elasohydrodynamic lubrication is the phenomenon that occurs when a lubricant is introduced between surfaces which are in rolling contact, such as mating gears or rolling bearings. The mathematical explanation requires the hertzian theory of contact stress and fluid mechanics.
When bearing must be operated at exetreme temperatures, a solid film lubricant such as graphite or molybdenum disulfide must be use used because the ordinary mineral oils are not satisfactory. Must research is currently being carried out in an effort, too, to find composite bearing materials with low wear rates as well as small frictional coefficients.
In a journal bearing, a shaft rotates or oscillates within the bearing , and the relative motion is sliding . in an antifriction bearing, the main relative motion is rolling . a follower may either roll or slide on the cam. Gear teeth mate with each other by a combination of rolling and sliding . pistions slide within their cylinders. All these applications require lubrication to reduce friction ,wear, and heating.
The field of application for journal bearing s is immense. The crankshaft and connecting rod bearings of an automotive engine must poerate for thousands of miles at high temperatures and under varying load conditions . the journal bearings used in the steam turbines of power generating station is said to have reliabilities approaching 100 percent. At the other extreme there are thousands of applications in which the loads are light and the service relatively unimportant. a simple ,easily installed bearing is required ,suing little or no lubrication. In such cases an antifriction bearing might be a poor answer because because of the cost, the close ,the radial space required ,or the increased inertial effects. Recent metallurgy developments in bearing materials , combined with increased knowledge of the lubrication process, now make it possible to design journal bearings with satisfactory lives and very good reliabilities.
外文下載地址：https://wenku.baidu.com/view/92938a48767f5acfa1c7cd89.html
軸承的摩擦與潤(rùn)滑
許多學(xué)生在被問到關(guān)于摩擦的問題時(shí)，往往都沒引起足夠的重視，甚至是忽視它，現(xiàn)在就有很多這種情況。實(shí)際上，從某種程度上說(shuō)摩擦存在于任何兩個(gè)相接觸并有相對(duì)運(yùn)動(dòng)趨勢(shì)的部件之間。而摩擦這個(gè)詞，本身就意味著兩個(gè)或兩個(gè)以上部件的阻止相對(duì)運(yùn)動(dòng)趨勢(shì)。
在一個(gè)機(jī)器中，運(yùn)動(dòng)部件的摩擦是有害的，因?yàn)樗档土藱C(jī)械對(duì)能量的充分利用。由它引起的熱能是一種浪費(fèi)的能量，因此不能用它做任何事情。還有，它還需要更大的動(dòng)力來(lái)克服這種不斷增大的摩擦。熱能是有破壞性的，因?yàn)樗a(chǎn)生了膨脹，而膨脹可以使得軸承或滑動(dòng)表面之間的配合更緊密。如果因?yàn)榕蛎泴?dǎo)致了一個(gè)足夠大的積壓力，那么這個(gè)軸承就可能會(huì)卡死或密封死。另外，隨著溫度的升高，如果不是耐高溫材料制造的軸承，就可能會(huì)損壞甚至融化。
在運(yùn)動(dòng)部件之間會(huì)發(fā)生很多摩擦，如
1.啟動(dòng)摩擦
2.滑動(dòng)摩擦
3.轉(zhuǎn)動(dòng)摩擦
啟動(dòng)摩擦是兩個(gè)固體之間產(chǎn)生的傾向于阻止其相對(duì)運(yùn)動(dòng)趨勢(shì)的摩擦。當(dāng)兩個(gè)固體處于靜止?fàn)顟B(tài)時(shí)，這兩個(gè)零件表面的不平度傾向于相互嵌入，形成楔入作用，為了使這些部件“動(dòng)”起來(lái)，這些靜止部件的凹谷和尖峰必須整理光滑，而且能相互抵消。這兩個(gè)表面之間越不光滑，由運(yùn)動(dòng)造成的啟動(dòng)摩擦（最大靜摩擦力）就會(huì)越大。
因?yàn)?，通常?lái)說(shuō)，在兩個(gè)相互配合的部件之間，其表面不平度沒有固定的圖形一旦運(yùn)動(dòng)部件運(yùn)動(dòng)起來(lái)，便有了規(guī)律可循，滑動(dòng)就可以實(shí)現(xiàn)這一點(diǎn)，兩個(gè)運(yùn)動(dòng)部件之間的摩擦就叫做滑動(dòng)摩擦。啟動(dòng)摩擦通常都稍大于滑動(dòng)摩擦。
轉(zhuǎn)動(dòng)摩擦一般發(fā)生在轉(zhuǎn)動(dòng)部件和設(shè)備上，這些設(shè)備“抵觸”極大的外作用力，當(dāng)然這種外力會(huì)導(dǎo)致部件的變形和性能的改變。在這種情況下，轉(zhuǎn)動(dòng)件的材料趨向于堆積并且強(qiáng)迫運(yùn)動(dòng)部件緩慢運(yùn)動(dòng)，這種改變就是通常所說(shuō)的形變，可以使分子運(yùn)動(dòng)。當(dāng)然，最終的結(jié)果是這種額外的能量產(chǎn)生了熱能，這是必需的，因?yàn)樗梢员ＷC運(yùn)動(dòng)部件的運(yùn)動(dòng)和克服摩擦力。
由運(yùn)動(dòng)部件的表面不平度的楔入作用引起的摩擦可以被部分的克服，那就需要靠?jī)杀砻嬷g的潤(rùn)滑。但是，即使是非常光滑的兩個(gè)表面之間也可能需要一種物質(zhì)，這種物質(zhì)就是通常所說(shuō)的潤(rùn)滑劑，它可以提供一個(gè)比較好的、比較薄的油膜。這個(gè)油膜使兩個(gè)表面分離，并且組織運(yùn)動(dòng)部件的兩個(gè)表面的相互潛入，以免產(chǎn)生熱量使兩表面膨脹，又引起更近的接觸。
減小摩擦的另一種方式是用不同的材料制造軸承和轉(zhuǎn)動(dòng)零件?？梢阅命S銅軸承、鋁合金和含油軸承合金做例子進(jìn)行解釋。也就是說(shuō)用軟的或硬的金屬組成表面。含油軸承合金是軟的，這樣，當(dāng)軸承在油中浸泡過(guò)以后，因?yàn)槊?xì)管的作用，將由帶到軸承的各個(gè)表面，這種類型的軸承把它的潤(rùn)滑劑帶到應(yīng)力最大的部位。
對(duì)運(yùn)動(dòng)部件潤(rùn)滑以減小摩擦應(yīng)力和熱量，最常用的是油、脂、還有合成劑。每一種潤(rùn)滑劑都有其各自不同的功能和用途。兩個(gè)運(yùn)動(dòng)部件之間的運(yùn)動(dòng)情況決定了潤(rùn)滑劑的類型的選擇，潤(rùn)滑劑的分布也決定了系統(tǒng)的選擇。
在低速度運(yùn)動(dòng)的部件，一個(gè)油溝足以將所需要的數(shù)量的潤(rùn)滑劑送到相互運(yùn)動(dòng)的表面。
第二種通用的潤(rùn)滑方法是飛濺潤(rùn)滑系統(tǒng)，在每個(gè)周期內(nèi)這個(gè)系統(tǒng)內(nèi)一些零件經(jīng)過(guò)潤(rùn)滑劑存儲(chǔ)的位置，帶起足夠的潤(rùn)滑油，然后將其散布到所有的運(yùn)動(dòng)零件上。這種系統(tǒng)用于草坪修剪機(jī)中發(fā)動(dòng)機(jī)的曲軸箱，對(duì)曲軸、連桿和活塞等零件進(jìn)行潤(rùn)滑。
在工業(yè)裝置中，常用的有一種潤(rùn)滑系統(tǒng)是壓力系統(tǒng)。這種系統(tǒng)中，一個(gè)機(jī)器上的一個(gè)泵，可以將潤(rùn)滑劑帶到所有的軸承表面，并且以一種連續(xù)的固定的速度和數(shù)量。
關(guān)于潤(rùn)滑，還有許多其他的系統(tǒng)，各種類型的潤(rùn)滑劑針對(duì)不同類型的運(yùn)動(dòng)零件有效。由于設(shè)備或裝置的速度、壓力和工作要求的提高，現(xiàn)代工業(yè)比以前任何時(shí)候都更注重選用適當(dāng)?shù)臐?rùn)滑劑。
盡管潤(rùn)滑的主要目的之一是為了減小摩擦力，任何可以控制兩個(gè)滑動(dòng)表面之間摩擦和磨損的物質(zhì)，不管是液體還是固體或氣體，都可以歸類于潤(rùn)滑劑。
潤(rùn)滑的種類
無(wú)潤(rùn)滑滑動(dòng):經(jīng)過(guò)精心處理的、去除了所有外來(lái)物質(zhì)的金屬在相互滑動(dòng)時(shí)會(huì)粘附或熔接到一起。當(dāng)達(dá)不到這么高的純凈度時(shí)，吸附在表面的氣體、水蒸氣、氧化物和污染物就會(huì)降低摩擦力并減小粘附的趨勢(shì)，但通常會(huì)產(chǎn)生嚴(yán)重的磨損，這種現(xiàn)象被稱為“無(wú)潤(rùn)滑”摩擦或者叫做干摩擦。
流體膜潤(rùn)滑:在滑動(dòng)面之間引入一層流體膜，把滑動(dòng)表面完全隔離開，就產(chǎn)生了流體膜潤(rùn)滑。這種流體可能是有意引入的，例如汽車主軸承中的潤(rùn)滑油；也可能是無(wú)意中引入的，例如在光滑的橡膠輪胎和潮濕的路面之間的水。盡管流體通常是油、水和其他很多種類的液體，它也可以是氣體，最常用的氣體是空氣。
為了把零件隔離開，潤(rùn)滑膜中的壓力必須和作用在滑動(dòng)面上的負(fù)荷保持平衡。如果潤(rùn)滑膜中的壓力是由外源提供的，這種系統(tǒng)就稱為流體靜壓潤(rùn)滑。如果滑動(dòng)表面之間的壓力是由于滑動(dòng)面本身的形狀和運(yùn)動(dòng)所共同產(chǎn)生的，這種系統(tǒng)就稱為流體動(dòng)壓力潤(rùn)滑。
邊界潤(rùn)滑:處于無(wú)潤(rùn)滑滑動(dòng)和流體膜潤(rùn)滑之間的潤(rùn)滑被稱為邊界潤(rùn)滑。它可以被定為這樣一種潤(rùn)滑狀態(tài)，在這種狀態(tài)中，表面之間的摩擦力取決于表面的性質(zhì)和潤(rùn)滑劑中的其他性質(zhì)。邊界潤(rùn)滑包括大部分潤(rùn)滑現(xiàn)象，通常在機(jī)器的啟動(dòng)和停止時(shí)出現(xiàn)。
固體潤(rùn)滑：當(dāng)普通潤(rùn)滑劑沒有足夠的承受能力或者不能在溫度極限下工作時(shí)，石墨和二硫化鉬這一類固體潤(rùn)滑劑得到廣泛應(yīng)用。但潤(rùn)滑劑不僅僅以脂肪、粉末和油脂這樣一些為人們所熟悉的形態(tài)出現(xiàn)，在一些精密的機(jī)器中，金屬也通常作為滑動(dòng)面。
潤(rùn)滑劑的作用
盡管潤(rùn)滑劑主要是用來(lái)控制摩擦和磨損的，它們能夠而且通常也確實(shí)起到許多其他的作用，這些作用隨其用途不同而不同，但通常相互之間是有關(guān)系的。
控制摩擦力：滑動(dòng)面之間潤(rùn)滑劑的數(shù)量和性質(zhì)對(duì)所產(chǎn)生的摩擦力有很大的影響，例如，不考慮熱和磨損這些相關(guān)因素，只考慮兩個(gè)油膜潤(rùn)滑表面見的摩擦力，它能比兩個(gè)相同但沒有潤(rùn)滑的表面小200倍。在流體潤(rùn)滑狀況時(shí)，摩擦力與流體黏度成正比。一些諸如石油衍生物這類潤(rùn)滑劑，可以有很多黏度，因此能夠滿足范圍寬廣的功能要求。在邊界潤(rùn)滑狀態(tài)，潤(rùn)滑劑黏度對(duì)摩擦力的影響不象其化學(xué)性質(zhì)的影響那么顯著。
磨損控制：磨蝕、腐蝕與固體和固體之間的接觸就會(huì)造成磨損。適當(dāng)?shù)臐?rùn)滑劑將能幫助克服上述提到的一些磨損現(xiàn)象。潤(rùn)滑劑通過(guò)潤(rùn)滑膜來(lái)增加滑動(dòng)面之間的距離，從而減輕磨料污染物和表面不平度造成的損傷，因此，減輕了磨損和由固體與固體之間接觸造成的磨損。
控制溫度：潤(rùn)滑劑通過(guò)減小摩擦和將產(chǎn)生的熱量帶走來(lái)降低溫度，其效果取決于潤(rùn)滑劑的用量和外部冷卻措施。冷卻劑的種類也會(huì)在較小的程度上影響表面的溫度。
控制腐蝕：潤(rùn)滑劑在控制表面腐蝕方面有雙重作用。當(dāng)機(jī)器閑置不工作時(shí)，潤(rùn)滑劑起到防腐劑的作用。當(dāng)機(jī)器工作時(shí)，潤(rùn)滑劑通過(guò)給被潤(rùn)滑零件涂上一層添加劑，能使腐蝕性材料中和的保護(hù)膜來(lái)控制腐蝕。潤(rùn)滑劑控制腐蝕的能力與潤(rùn)滑劑保留在金屬表面的潤(rùn)滑膜的厚度和潤(rùn)滑劑的化學(xué)成分有直接的關(guān)系。
其他作用
除了減小摩擦外，潤(rùn)滑劑還經(jīng)常有其他的用途，其中的一些用途如下所述。
傳遞動(dòng)力：潤(rùn)滑劑被廣泛用來(lái)作為液壓傳動(dòng)中的工作液體。
絕緣：在象變壓器和配電裝置這些特殊用途中，具有很高介電常數(shù)的潤(rùn)滑劑起電絕緣材料的作用。為了獲得最高絕緣性能，潤(rùn)滑劑中不能含有任何雜質(zhì)和水分。
減振：在象減振器這樣的能量傳遞裝置中和在承受很高的間隙載荷的齒輪這樣的機(jī)器零件的周圍，潤(rùn)滑劑被作為減振液使用。
密封：潤(rùn)滑脂通常還有一個(gè)特殊作用，就是形成密封層以防止?jié)櫥瑒┩鉃a和污染物進(jìn)入。
潤(rùn)滑的目的就是為了，減小摩擦力，降低能量損耗，減少機(jī)器的熱量產(chǎn)生。熱量是因?yàn)楸砻娴南嗷ラg的相對(duì)運(yùn)動(dòng)造成的，潤(rùn)滑劑可以是任何一種物質(zhì)，這樣的物質(zhì)被填充到發(fā)生相對(duì)運(yùn)動(dòng)的兩個(gè)表面之間，實(shí)現(xiàn)這一目的。大部分的潤(rùn)滑劑是液體，比如說(shuō)，油，脂，合成劑等。但它們有時(shí)也可能是固體，用在干軸承上，有的用在旋轉(zhuǎn)基體的軸承上，或者也可能是氣體，如空氣等，它是用在空氣軸承上。在潤(rùn)滑劑和潤(rùn)滑表面之間這種化學(xué)的和物質(zhì)的相互滲入作用，就是為了提供給機(jī)器一個(gè)良好的工作狀態(tài)。
對(duì)潤(rùn)滑劑邊界的理解，往往是比較硬的，而且是流動(dòng)的、非常薄的一層帖附在被潤(rùn)滑的表面。這些表面通常是要發(fā)生相對(duì)滑動(dòng)。有些人推斷，按這種理解，液體的這種化學(xué)合成是十分重要的，它們提出了“邊界潤(rùn)滑”這樣的詞，邊界潤(rùn)滑是和流體潤(rùn)滑相對(duì)的另一種潤(rùn)滑。
關(guān)于潤(rùn)滑的五種不同的潤(rùn)滑形式主要有：
（1）無(wú)潤(rùn)滑潤(rùn)滑劑。
（2）流體膜潤(rùn)滑。
（3）干潤(rùn)滑。
（4）邊界潤(rùn)滑。
（5）固體潤(rùn)滑。
無(wú)潤(rùn)滑潤(rùn)滑劑是指軸承的工作表面被一種相對(duì)比較厚的液體潤(rùn)滑劑分隔開，于是阻止了金屬表面的直接接觸，這樣得到的這種穩(wěn)定性就可以用一種理論來(lái)解釋：潤(rùn)滑液在外壓力下工作的理論，盡管這只是一種可能，但去確實(shí)在任何時(shí)候都需要提供的足夠充分。這種擠壓力是運(yùn)動(dòng)表面本身施加給潤(rùn)滑劑而產(chǎn)生的，當(dāng)然這仍然是一種可能。這種由運(yùn)動(dòng)表面產(chǎn)生的擠壓力產(chǎn)生了必要的壓力來(lái)分隔工作表面，從而抵抗加在軸承上的載荷。所以，這種潤(rùn)滑也可以被叫做液體潤(rùn)滑。
還有一種潤(rùn)滑方式，那是一種特別的潤(rùn)滑劑，它有時(shí)是空氣或水，當(dāng)加在軸承上的外載荷足夠高時(shí)，它就會(huì)以一種比較厚的狀態(tài)分隔開相互相對(duì)運(yùn)動(dòng)的工作表面。所以，不象上面的那種潤(rùn)滑方式，并不需要兩種工作表面一定發(fā)生相對(duì)運(yùn)動(dòng)。
第三種潤(rùn)滑方式是一種現(xiàn)象，這種現(xiàn)象是，一種潤(rùn)滑劑是用在發(fā)生相對(duì)轉(zhuǎn)動(dòng)的工作表面之間。比如說(shuō)齒輪或者是滾動(dòng)軸承。從數(shù)學(xué)上了來(lái)講，需要用接觸壓力和流體機(jī)械的理論來(lái)解釋。
當(dāng)軸承不得不在較高的溫度下工作的時(shí)候，固體潤(rùn)滑劑例如合成物等，必須被使用，因?yàn)橥ǔＪ褂玫臐?rùn)滑油在這種情況下都不能工作。目前，在這方面的研究正在實(shí)施，為了尋找到合成軸承，并且有低損耗和小的熱量產(chǎn)生的性能的材料，。
在有的軸承上，搖桿旋轉(zhuǎn)或在軸承上轉(zhuǎn)動(dòng)，相對(duì)運(yùn)動(dòng)就是滑動(dòng)。在一個(gè)自鎖的軸承裝置中，這種相對(duì)運(yùn)動(dòng)就是轉(zhuǎn)動(dòng)。其他的裝置也可能是旋轉(zhuǎn)或滑動(dòng)。齒輪的齒嚙合是轉(zhuǎn)動(dòng)與相對(duì)滑動(dòng)的合成?；钊窍鄬?duì)于剛體的滑動(dòng)，所有的這些應(yīng)用都需要潤(rùn)滑劑來(lái)減小摩擦，降低能耗，減少熱量的產(chǎn)生。
在有些軸承的應(yīng)用領(lǐng)域是不太成熟的。有些有連接桿的軸承，比如說(shuō)汽車發(fā)動(dòng)機(jī)上的，必須在幾千度高的高溫下和各種不同性質(zhì)的載荷下工作。這種軸承用在汽輪發(fā)動(dòng)設(shè)備上可以說(shuō)是穩(wěn)定性接近100%。還有另一種極端的情況，在有些軸承有幾千種應(yīng)用，應(yīng)對(duì)各種不同的載荷。其他的輔助設(shè)施就相對(duì)不重要了，需要的是一個(gè)簡(jiǎn)單的、容易安裝的軸承。需要很少的甚至是不需要潤(rùn)滑劑。在這種情況下，有的軸承并不是最好的選擇，因?yàn)槌杀竞拖嘟墓?。最近在軸承材料上的研究已有了一定的突破。隨著對(duì)潤(rùn)滑的研究的知識(shí)的積累，設(shè)計(jì)出有良好工作狀況和較高的穩(wěn)定性的軸承已不是很遙遠(yuǎn)了。
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