購(gòu)買設(shè)計(jì)請(qǐng)充值后下載，，資源目錄下的文件所見(jiàn)即所得，都可以點(diǎn)開(kāi)預(yù)覽，，資料完整，充值下載可得到資源目錄里的所有文件。。?！咀ⅰ浚篸wg后綴為CAD圖紙，doc,docx為WORD文檔，原稿無(wú)水印，可編輯。。。具體請(qǐng)見(jiàn)文件預(yù)覽，有不明白之處，可咨詢QQ:12401814

河南理工大學(xué)萬(wàn)方科技學(xué)院 本科畢業(yè)設(shè)計(jì)（論文）開(kāi)題報(bào)告 題目名稱 沖壓模具設(shè)計(jì) 學(xué)生姓名 專業(yè)班級(jí) 學(xué)號(hào) 一、 選題的目的和意義 工業(yè)發(fā)展水平的不斷提高，工業(yè)產(chǎn)品更新速度加快，對(duì)模具的要求越來(lái)越高，盡管改革開(kāi)放以來(lái)，模具工業(yè)有了較大發(fā)展，但無(wú)論是數(shù)量還是質(zhì)量仍滿足不了國(guó)內(nèi)市場(chǎng)的需要，目前滿足率只能達(dá)到70%左右。造成產(chǎn)需矛盾突出的原因，一是專業(yè)化、標(biāo)準(zhǔn)化程度低，除少量標(biāo)準(zhǔn)件外購(gòu)?fù)?，大部分工作量均需模具廠去完成。加工企業(yè)管理的體制上的約束，造成模具制造周期長(zhǎng)，不能適應(yīng)市場(chǎng)要求。二是設(shè)計(jì)和工藝技術(shù)落后，如模具CAD/CAM技術(shù)采用不普遍，加工設(shè)備數(shù)控化率低等，亦造成模具生產(chǎn)效率不高、周期長(zhǎng)?？傊峭狭藱C(jī)電、輕工等行業(yè)發(fā)展的后腿。 模具影響著制品的質(zhì)量。首先，模具型腔的形狀、尺寸、表面光潔度、分型面、進(jìn)澆口和排氣槽位置以及脫模方式等對(duì)制件的尺寸精度和形狀精度以及制件的物理性能、機(jī)械性能、電性能、內(nèi)應(yīng)力大小、各向同性性、外觀質(zhì)量、表面光潔度、氣泡、凹痕、燒焦、銀紋等都有十分重要的影響。其次，在加工過(guò)程中，模具結(jié)構(gòu)對(duì)操作難以程度影響很大。在大批量生產(chǎn)塑料制品時(shí)，應(yīng)盡量減少開(kāi)模、合模的過(guò)程和取制件過(guò)程中的手工勞動(dòng)，為此，常采用自動(dòng)開(kāi)合模自動(dòng)頂出機(jī)構(gòu)，在全自動(dòng)生產(chǎn)時(shí)還要保證制品能自動(dòng)從模具中脫落。另外模具對(duì)制品的成本也有影響。當(dāng)批量不大時(shí)，模具的費(fèi)用在制件上的成本所占的比例將會(huì)很大，這時(shí)應(yīng)盡可能的采用結(jié)構(gòu)合理而簡(jiǎn)單的模具，以降低成本?，F(xiàn)代生產(chǎn)中，合理的加工工藝、高效的設(shè)備、先進(jìn)的模具是必不可少是三項(xiàng)重要因素，尤其是模具對(duì)實(shí)現(xiàn)材料加工工藝要求、塑料制件的使用要求和造型設(shè)計(jì)起著重要的作用。高效的全自動(dòng)設(shè)備也只有裝上能自動(dòng)化生產(chǎn)的模具才有可能發(fā)揮其作用，產(chǎn)品的生產(chǎn)和更新都是以模具的制造和更新為前提的。由于制件品種和產(chǎn)量需求很大，對(duì)模具也提出了越來(lái)越高的要求。因此促進(jìn)模具的不斷向前發(fā)展 因此我們必須意識(shí)到，對(duì)模具設(shè)計(jì)的研究的目的和意義在于能夠很好的認(rèn)識(shí)模具工業(yè)在國(guó)民經(jīng)濟(jì)中的地位的重要性。因?yàn)槔媚＞叱尚土慵姆椒?，?shí)質(zhì)上是一種少切削、無(wú)切削、多工序重合的生產(chǎn)方法，采用模具成型的工藝代替?zhèn)鹘y(tǒng)的切削加工工藝，可以提高生產(chǎn)效率，保證零件質(zhì)量，節(jié)約材料，降低生產(chǎn)成本，從而取得很高的經(jīng)濟(jì)效益。利用模具生產(chǎn)零件的方法已經(jīng)成為工業(yè)上進(jìn)行成批或大批生產(chǎn)的主要技術(shù)手段，它對(duì)保證制品質(zhì)量，縮短試用周期，進(jìn)而爭(zhēng)先占領(lǐng)市場(chǎng)，以及產(chǎn)品更新?lián)Q代和新產(chǎn)品開(kāi)發(fā)都具有決定性的意義。因此德國(guó)把模具稱為“金屬加工中的帝王”，把模具工業(yè)視為“關(guān)鍵工業(yè)”，美國(guó)把模具稱為“美國(guó)工業(yè)的基石”，把模具工業(yè)視為“不可估量其力量的工業(yè)”，日本把模具說(shuō)成是“促進(jìn)社會(huì)富裕繁榮的動(dòng)力”，把模具視為“整個(gè)工業(yè)發(fā)展的秘密”。因此，要使國(guó)民經(jīng)濟(jì)各個(gè)部門獲得高速發(fā)展，加速實(shí)現(xiàn)社會(huì)主義四個(gè)現(xiàn)代化，就必須盡快將模具工業(yè)搞上去，使模具生產(chǎn)形成一個(gè)獨(dú)立的工業(yè)部門，從而充分發(fā)揮模具工業(yè)在國(guó)民經(jīng)濟(jì)中的關(guān)鍵作用 二、 國(guó)內(nèi)外研究綜述： 1、 國(guó)外 (1) 級(jí)進(jìn)模制造技術(shù)研究現(xiàn)狀 隨著科學(xué)技術(shù)的不斷進(jìn)步，工業(yè)產(chǎn)品日益復(fù)雜與多樣化，產(chǎn)品性能和質(zhì)量也在不段提高，因而對(duì)沖壓技術(shù)提出了更高的要求。沖壓技術(shù)自身也在不斷的創(chuàng)新和發(fā)展。為了適應(yīng)大批量、高效率生產(chǎn)的需求，在沖壓模具和設(shè)備上廣泛應(yīng)用了各種自動(dòng)化的進(jìn)、出料機(jī)構(gòu)，對(duì)于大型沖壓件，例如汽車覆蓋件，專門配置了機(jī)械手或機(jī)器人，這不僅大大提高了沖壓件的生產(chǎn)品質(zhì)和生產(chǎn)率，而且也增加了沖壓工作的安全性。在中、小件的大批量生產(chǎn)方面，現(xiàn)已廣泛應(yīng)用多工位級(jí)模、多工位壓力機(jī)或高速壓力機(jī)。在中、小批量多 品種生產(chǎn)方面，正在發(fā)展柔性制造系統(tǒng)，為了適應(yīng)多品種生產(chǎn)時(shí)不斷更換模具的需要，已成功地開(kāi)發(fā)出快速換模系統(tǒng)。 （2）多工位級(jí)進(jìn)模的發(fā)展趨勢(shì) 隨著工業(yè)產(chǎn)品質(zhì)量的不斷提高，沖壓產(chǎn)品正呈現(xiàn)多品種、少批量、復(fù)雜、大型、精 密 等更新?lián)Q代速度快的變化特點(diǎn)，沖壓模具正向高效、精密、長(zhǎng)壽命、大型化方向發(fā)展。為 適應(yīng)市場(chǎng)變化，隨著計(jì)算機(jī)技術(shù)和制造技術(shù)的迅速發(fā)展，沖壓模具設(shè)計(jì)的制造技術(shù)也真有手工設(shè)計(jì)、依靠人工經(jīng)驗(yàn)和常規(guī)機(jī)械加工技術(shù)向以計(jì)算機(jī)輔助設(shè)計(jì)（CAD）、數(shù)控切削技術(shù)、數(shù)控電加工為核心的計(jì)算機(jī)輔助設(shè)計(jì)與制造（CAD/CAM）技術(shù)轉(zhuǎn)變。 2、 國(guó)內(nèi) 現(xiàn)代模具工業(yè)有“不衰亡工業(yè)”之稱。世界模具市場(chǎng)總體上供不應(yīng)求，市場(chǎng)需求量維持在600億至650億美元，同時(shí)，我國(guó)的模具產(chǎn)業(yè)也迎來(lái)了新一輪的發(fā)展機(jī)遇。近幾年，我國(guó)模具產(chǎn)業(yè)總產(chǎn)值保持13%的年增長(zhǎng)率（據(jù)不完全統(tǒng)計(jì)，2004年國(guó)內(nèi)模具進(jìn)口總值達(dá)到600多億，同時(shí)，有近200個(gè)億的出口），到2005年模具產(chǎn)值預(yù)計(jì)為600億元，模具及模具標(biāo)準(zhǔn)件出口將從現(xiàn)在的每年9000多萬(wàn)美元增長(zhǎng)到2005年的2億美元左右。單就汽車產(chǎn)業(yè)而言，一個(gè)型號(hào)的汽車所需模具達(dá)幾千副，價(jià)值上億元，而當(dāng)汽車更換車型時(shí)約有80%的模具需要更換。2003年我國(guó)汽車產(chǎn)銷量均突破400萬(wàn)輛，預(yù)計(jì)2004年產(chǎn)銷量各突破500萬(wàn)輛，轎車產(chǎn)量將達(dá)到260萬(wàn)輛。另外，電子和通訊產(chǎn)品對(duì)模具的需求也非常大，在發(fā)達(dá)國(guó)家往往占到模具市場(chǎng)總量的20%之多。目前，中國(guó)17000多個(gè)模具生產(chǎn)廠點(diǎn)，從業(yè)人數(shù)約50多萬(wàn)。1999年中國(guó)模具工業(yè)總產(chǎn)值已達(dá)245億元人民幣。工業(yè)總產(chǎn)值中企業(yè)自產(chǎn)自用的約占三分之二，作為商品銷售的約占三分之一。在模具工業(yè)的總產(chǎn)值中，沖壓模具約占50%，塑料模具約占33%，壓鑄模具約占6%，其它各類模具約占11%。 三、 畢業(yè)設(shè)計(jì)（論文）所用的主要技術(shù)與方法： 1、 首先查閱相關(guān)的資料,了解與課題有關(guān)的背景知識(shí) 2、 查閱專業(yè)書(shū)籍,掌握課題設(shè)計(jì)的技術(shù)要點(diǎn) 3、 按照有關(guān)的計(jì)算公式進(jìn)行計(jì)算 4、 用計(jì)算機(jī)繪圖軟件(CAD CAXA PRO/E)繪制主要零件圖及三維圖 四、 主要參考文獻(xiàn)與資料獲得情況： [1]黃毅宏著，《模具制造工藝》，北京 機(jī)械工業(yè)出版社，2000年，1-4 [2]李發(fā)致著，《模具先進(jìn)制造技術(shù)，北京 機(jī)械工業(yè)出版社，2003年，1-13 [3]高佩福著，實(shí)用模具制造技術(shù)》，第二版，北京 中國(guó)輕工業(yè)出版社，2000年 [4]萬(wàn)戰(zhàn)勝著，《沖壓工藝及模具設(shè)計(jì)》，北京 中國(guó)鐵道出版社，1995年 [5]模具實(shí)際與制造技術(shù)教育叢書(shū)編委會(huì)編，《模具結(jié)構(gòu)設(shè)計(jì)》，機(jī)械工業(yè)出版社， 2004年 [6]王樹(shù)勛著，《模具實(shí)用技術(shù)設(shè)計(jì)綜合手冊(cè)》，廣州 華南理工大學(xué)出版社，1995年 五、 畢業(yè)設(shè)計(jì)（論文）進(jìn)度安排（按周說(shuō)明） 1、 1-4周畢業(yè)實(shí)習(xí)(實(shí)習(xí)報(bào)告) 2、 5-7周收集與課題相關(guān)的資料,熟悉課題背景,撰寫開(kāi)題報(bào)告. 3、 8-9周進(jìn)行方案論證,初步設(shè)計(jì),繪制草圖及初步計(jì)算 4、 10周繪制裝配圖和主要零件圖 5、 11周撰寫畢業(yè)設(shè)計(jì)說(shuō)明書(shū) 六、 指導(dǎo)教師審批意見(jiàn)： 指導(dǎo)教師： （簽名） 年 月 日 河南理工大學(xué)萬(wàn)方科技學(xué)院 本科畢業(yè)設(shè)計(jì)（論文）中期檢查表 指導(dǎo)教師： 職稱： 所在院（系）： 教研室（研究室）： 題 目 沖壓模具設(shè)計(jì) 學(xué)生姓名 專業(yè)班級(jí) 學(xué)號(hào) 一、選題質(zhì)量：（主要從以下四個(gè)方面填寫：1、選題是否符合專業(yè)培養(yǎng)目標(biāo)，能否體現(xiàn)綜合訓(xùn)練要求；2、題目難易程度；3、題目工作量；4、題目與生產(chǎn)、科研、經(jīng)濟(jì)、社會(huì)、文化及實(shí)驗(yàn)室建設(shè)等實(shí)際的結(jié)合程度） 1、 選題與專業(yè)對(duì)口，課題的的設(shè)計(jì)，能綜合訓(xùn)練專業(yè)知識(shí)與實(shí)踐的結(jié)合 2、 題目難度適中 3、 題目工作量稍大 4、 題目與工業(yè)生產(chǎn)聯(lián)系緊密 二、開(kāi)題報(bào)告完成情況： 開(kāi)題報(bào)告已完成 三、階段性成果： 1、對(duì)沖壓模具的國(guó)內(nèi)外的發(fā)展與研究有所了解 2、查閱了有關(guān)沖壓模具的論文及科技期刊 3、了解了沖壓模具的有關(guān)計(jì)算及繪圖 四、存在主要問(wèn)題： 1、要對(duì)模具的三維建模要求較高 2、繪圖不易把握 五、指導(dǎo)教師對(duì)學(xué)生在畢業(yè)實(shí)習(xí)中，勞動(dòng)、學(xué)習(xí)紀(jì)律及畢業(yè)設(shè)計(jì)（論文）進(jìn)展等方面的評(píng)語(yǔ) 指導(dǎo)教師： （簽名） 年 月 日 8 STUDY ON SLIPPERS FOR RAW WATER HYDRAULIC AXIAL PISTON PUMPS AND MOTORS' 1. Abstract As concerns for environmental compatibility, safetyand hygienic requirements, hydraulic systems using rawwater as pressure medium become more and moreattractive. A raw water hydraulic system has many advantages over conventional oil hydraulic systems,such as: environmentally compatibility, no pollution and no fire hazard, elimination of expensive oils with the associated problems of contamination, maintenance,storage, handling, elimination of the return hose, and elimination of health hazards, etc. But as a hydraulic medium, raw water has also drawbacks, such as very low viscosity, high vapor pressure, lack of lubrication and chemically active nature, etc., that all tend to promote problems of corrosion, wear, cavitation erosion, leakage, and so on, those problems must be overcome in the design and development of the raw water hydraulic components, especially the selection of materials and design of structure for the friction pairs in raw water hydraulic pumps and motors. The slipper/swashplate pair is one of the very important friction pairs in axial piston pumps and motors. Under the lubrication of raw water. materials for slipper/swashplate combination should have superior mechanical strength, low friction, resistance to corrosion, abrasion, cavitation erosion and sliding wear, and the structure of the slipper should be suitable for the characteristics of raw water and materials used Based on authois researches, a new slipper foraxial piston pumps and motors is introduced in this paper. From tests with the slipper/swashplate lest rig, it shows that the new type slipper combined with appropriate swashplate has good tribological characteristics. This slipper can operate with raw water, even sea water. The successful study on slippers will provide good helps for design and development of raw water hydraulic axial piston pumps and motors with higher performance. 2. Introduction The use of water as hydraulic fluid is not new. The first hydraulic machine as a means of transmitting not only energy but also control signals is raw water hydraulic press that manufactured by Joseph Bramah in 1795, which marks the beginning of the age of modern applied hydraulics. After that almost 100 years raw water was used as hydraulic medium, until the beginning of 20th century the mineral oil began to take the place of raw water. Because of the much better lubrication and anti-corrosi on properbes of mineral oil as compared with raw water and the development of oil resistant sealing materials, oil hydraulics boosted quickly and raw water hydraulics was left behind, gradually acquiring the image of an obsolete technology. As concerns over safe or environmental issues a number of other hydraulic fluids have been developed over the past decades, such as synthetic base fluids, water base fluids, and vegetable oil base fluids, etc. These fluids have their own advantages and a certain range of applications. For a given application, engineers can make the hydraulic system have satisfactory performance by careful hydraulic fluid choice and system design. However, these hydraulic fluids also have its own shortcomings,so me shortcomings of these fluids are inherent and fatal. No one of these hydraulic fluids can meet the requirements of fire resistance and environmentally protection at the same time, and most of these fluids are very expensive. The re-emergence of using raw water as hydraulic fluid is mainly because of the following reasons. (1) Environmental Protection Requirement Without strict adherence to specific control techniques, it is nearly impossible to eliminate the threat of leakage in hydraulic systems. Industry observers believe that as much as 85% of all hydraulic fluids eventually leave their systems through slow leaks, catastrophic line breaks, or failures of fittings and seals. The leakage of hydraulic fluids with some toxic chemical additives not only make working conditions messy and unsafe, but also can not be biodegradable and have potential threat to the environment. Raw water has very good environmental compatibility and no pollution; water in the event of leakage eventually evaporates without leaving greasy or dirty residuals needs of applications for water hydraulics. The need of new applications is the intrinsic force of re-emergence and development of water hydraulics (2) Requirement of Safety Mineral oil are flammable, its leakage or spilling from systems may be result in a fire when in or near heat sources. Water is not flammable and does not present a fire hazard. In some areas, such as steel and glass production, iron making and foundry, injection molding, die casting, nuclear power, coal mining, etc. the requirement of safety is prime, so raw water hydraulics may be the best choice in the near future (3) Hygienic Requirement In some fields, such as gold mining, food and medicine processing, water supply industry, etc , where escaping of oil or chemical additives from hydraulic systems can smear the product and damage the quality of manufactured product. Under these conditions, raw water is an ideal pressure medium. (4) Economy Requirement Water is available everywhere, needing no purchase, transport, storage, maintenance and disposal costs, so using water instead of mineral oil and other hydraulic fluids may offer tremendous economy. In ambient water environment, the system using raw water as hydraulic fluid can be designed as an open circuit.That means the return lines and water reservoir can be eliminated, further more the heater and the cooler of system are no longer needed, so the volume and weight of hydraulic equipment will reduced and the efficiency of system increased. If used underwater, such as in marine engineering, ocean exploration engineering, subsea equipment, underwater operation tools and robots, etc., water hydraulics can automatically counterbalance the water hydrostatic head, this is very important for improving the efficiency and performance of the hydraulic systems. (5) Need of New Applications Along with the developments of modern science and technologies, many areas with special requirements provide many new opportunities of applications for water hydraulics. Such as fusion reactor equipment in nuclear power engineering, marine equipment and robots in ocean exploration engineering, etc，where the fire resistance, hygienic requirement, economy and environmental protection are all considered. Because of higher power density and smaller size of hydraulics than that of other power transmissions, there have urgent needs of applications for water hydraulics.The need of new applications is the intrinsic force of re-emergence and development of water hydraulics. 3. Material Selection The slipper/swashplate pair is one of the very important friction pairs in axial piston pumps and motors. Under the lubrication of raw water,ingenious material selection is necessary. In a typical axial swashplate is stationary piston pump or motor, the swashplate is stationary ; the swashplate angle with the shaft centerline determines the length of the piston stroke (see Fig. 1) When using raw water as lubricant,according to rawwater's chemically active nature, low viscositylubrication and high vapor pressure,more problem should be considered. Firstly, raw water especially seawater is more aggressive , a large number of ions in seawater result in that seawater have much higher electric conductivity and may lead to electrochemistry erosion. The materials used for slipper and swashplate inevitably suffer aggressive corrosion from raw water , and the materials used for traditional oil hydraulic components will not be suitable here. Secondly, the kinematic viscosity of water at 50℃ is approximately 0.55cs ,which is less than 1/30 of the viscosity of a typical mineral oil fluid. The very low viscosity must increase the difficulty of developing hydrodynamic film between slipper and swashplate,and the very small change of water’s viscosity with pressure means that elastohydrodynamic lubrication with hard materials is unlikely to occur. Hydraulic fluids with additives that aid in the boundary lubrication of contacting surface permit metal-on-metal contact without large amounts of surface damage or wear. Raw water contains on such additives and its lubrication is very poor. The poor lubrication of water is clearly one of its major dtawbacks, and will lead to increase contact fraction and possibly wear of contacting conponents. Indeed it is well documented that wear was the greatest problem experienced by the early users of water based fluids in axial piston pumps. Researches indicate that the elastohydrodynamic film of water is about 0.1μm thick at 3m/s and 20-60℃, the elastohydtodynamic film of HWBF is about 0.15μm thick at 0.19~1.27m/s and 23.5℃. So there are risks as high dry friction and strong wear between slipper and swashplate under the lubrication of raw water. Thirdly, the vapor pressure of water is much higher than that of mineral oil, which means that water boils or vaporizes much easier. Due to water’s high vapor pressure and high velocity flow caused be water’s low viscosity, the slipper and swashplate will be exposed to strong and fast cavitation erosion. So material selection for slipper/swashplate pair should depend on the operation conditions and the special properties of raw water. Materials for slipper/swashplate combination should have superior mechanical strength, low friction, resistance to aggressive corrosion, cavitation erosion,abrasion,and sliding wear, and should be easy available and cost low. 4.Structure Design The structure design of slipper is very important as well as the material selection. The use of polymers as the material of slipper will derive a new problem-how to make the slipper wrap on the ball-shaped head of piston. Probably the solution is to use corrosion resistant metals combined with polymers. The slipper can be divided into two parts. One is slipper pad made of polymer, directly contact on the swashplate, its main function is making the slipper have good tribological properties. The other is shoe made of corrosion resistant alloy, its main function is making the slipper wrap on the ball-shaped head of piston. This structure can take the advantages of both metal’s ductility and polymer’s good tribological property(see Fig.2). The main static forces exerted on slipper are show in Fig.3. The force F acted on slipper from piston head includes hydrostatic force Fp on the piston end, spring force Fs, inertia force Fa of piston and slipper, and friction force Ff between piston and cylinder bore as formula: The reaction force N from swashplate can be divided into two components, component Nh of hydrostatic bearing force and component Nm of mechanical surface pressure,as following: N=Nh+Nm The relationship of N and F is: F=N·cosα 5.Conclusions Based on author’s researches, some conclusions about material selection and structure design of slipper under lubrication of raw water can be summarized as following: (1) Slipper made of polymers combined with swashplate made of corrosion resistant alloys has superior tribological properties. (2) Cotton fiber-filled phenolics can be used to manufacture slipper for a certain application range of operation pressure below 14MPa. (3) The spring force exerted on slipper should be strong enough to keep about 0.1~0.2MPa contacting pressuer on the surfaces of slipper and swashplate. Farther tests are underway, and ceramics with good toughness will be introduced to manufacture slipper and swashplate. The experiences of study on slippers will provide good helps for design and development of raw water hydraulic axial piston pumps and motors. References [1] Joseph L. Foszcz, Hydraulic Fluid Choices, Plant Engineering, (8),1996,68. [2]Li Zhuangyun, et al, Development of Hydraulic Pump to Operate with Raw water, Proceedings of ASME Fluid Engineering Division Summer Meeting, Washington DC, USA, June 21-25,1998. [4]吳仁榮，水潤(rùn)滑滑動(dòng)軸承的設(shè)計(jì)計(jì)算，機(jī)電設(shè)備，（6），1997,30. [5]許耀銘，油膜理論與液壓泵和馬達(dá)的摩擦副設(shè)計(jì)，北京；機(jī)械工業(yè)出版社，1987. 關(guān)于自然水液壓軸向活塞泵和電動(dòng)機(jī)的滑動(dòng)部分的研究 1.摘要 基于環(huán)境和諧、安全和衛(wèi)生需要的考慮，液壓系統(tǒng)使用自然水作為壓力介質(zhì)這種現(xiàn)象變得越來(lái)越廣泛。一個(gè)自然水液壓系統(tǒng)相對(duì)于普通的油液壓系統(tǒng)有很多優(yōu)點(diǎn)，例如：環(huán)境和諧，沒(méi)有污染，沒(méi)有火的危害，與昂貴的油相關(guān)的危害、維護(hù)、貯存、管理問(wèn)題的消除，返回塑料管的消除和健康危害的消除等等。但是作為液壓系統(tǒng)的介質(zhì)，自然水也有一些缺點(diǎn)，例如非常低的粘性，很高的水蒸氣壓力，缺少潤(rùn)滑和化學(xué)性自然等等，都加劇了腐蝕、磨損、氣蝕侵蝕、泄露等問(wèn)題，這些問(wèn)題必須在設(shè)計(jì)和自然水液壓元件的發(fā)展，尤其是材料和自然水液壓泵和電動(dòng)機(jī)的摩擦部分的結(jié)構(gòu)設(shè)計(jì)中被克服。 滑動(dòng)部分/旋轉(zhuǎn)羅盤部分是軸向活塞泵和電動(dòng)機(jī)中的重要摩擦部分。在自然水的潤(rùn)滑下，滑動(dòng)部分和旋轉(zhuǎn)羅盤結(jié)合部分的材料應(yīng)該較好的機(jī)械強(qiáng)度、低摩擦力、腐蝕的抵抗性、磨損、氣蝕侵蝕和滑動(dòng)摩擦，并且滑動(dòng)部分的結(jié)構(gòu)應(yīng)該對(duì)于自然水和使用材料的特性是適合的。 根據(jù)作者的研究，一種新型的用于軸向活塞泵和電動(dòng)機(jī)上的滑塊會(huì)在這篇文章中介紹。從滑塊/旋轉(zhuǎn)羅盤部分試驗(yàn)中表明這種新型的與合適旋轉(zhuǎn)羅盤結(jié)合的滑塊有著非常好的摩擦特性。這種滑塊能夠用自然水潤(rùn)滑，甚至是海水也可以。這個(gè)關(guān)于滑塊的研究將會(huì)為自然水液壓軸向活塞泵和電動(dòng)機(jī)的更好發(fā)展提供好的幫助。 2.介紹 水用來(lái)作為液壓流體已經(jīng)不是新技術(shù)了。作為轉(zhuǎn)換能源和控制信號(hào)的一種方式，第一臺(tái)液壓機(jī)器就是自然水液體壓力，并且在1795年由杰瑟夫大量生產(chǎn)，同時(shí)也標(biāo)志著現(xiàn)代液壓時(shí)代的開(kāi)始。在那之后幾乎100年自然水被用作液壓介質(zhì)，直到20世紀(jì)的初期，油介質(zhì)開(kāi)始取代水介質(zhì)。和自然水相比，油介質(zhì)有更好的潤(rùn)滑和礦物油的抗腐蝕性，并且油抗性密封材料，油液壓裝置發(fā)展的很快，自然水液壓裝置就落后了，漸漸成為一種過(guò)時(shí)的技術(shù)了。 基于在安全和環(huán)境問(wèn)題方面的考慮，許多其他液壓流體已經(jīng)在過(guò)去的幾十年發(fā)展了，例如合成來(lái)源液體、水來(lái)源液體和蔬菜油來(lái)源液體等等。這些液體有著它們各自的優(yōu)點(diǎn)和確定的用途。對(duì)于一種給定的用途，工程師能夠通過(guò)合理的液壓流體選擇和系統(tǒng)設(shè)計(jì)來(lái)使液壓系統(tǒng)滿足這個(gè)條件。然而，這些液壓流體也存在著自身的缺點(diǎn)，其中的某些缺點(diǎn)是內(nèi)在的并且是重大的。這些液壓流體中沒(méi)有一種能同時(shí)滿足防火性和環(huán)保性的要求，同時(shí)大部分液體是很昂貴的。 使用自然水作為液壓流體主要由于以下幾個(gè)原因： （1）環(huán)境保護(hù)的需要 如果對(duì)于特殊控制技術(shù)沒(méi)有嚴(yán)格的遵守，評(píng)估液壓系統(tǒng)中的泄露威脅是不可能的。工業(yè)觀察員相信所有液壓流體中85%的流體最后都是通過(guò)緩慢泄露、嚴(yán)重的連接破損或者設(shè)備和密封的故障而離開(kāi)液壓系統(tǒng)的。液壓流體和一些有毒的化學(xué)添加劑的泄露不僅使工作條件混亂和不安全，同時(shí)也不能生物降解和對(duì)環(huán)境存在潛在的危害。自然水擁有很好的環(huán)境適應(yīng)性并且沒(méi)有污染；水在泄露后也會(huì)消失而沒(méi)有油膩和臟的殘留物。 （2）安全的需要 礦物油是可燃的，當(dāng)周圍有熱源的時(shí)候它的泄露可能會(huì)導(dǎo)致起火。水是不可燃的，所以不會(huì)存在起火隱患。在一些區(qū)域，例如鋼鐵和玻璃生產(chǎn)，鋼鐵制造和鑄造，注射模具，拉模鑄造，核動(dòng)力，采煤等等，對(duì)于安全的要求是主要的，因此自然水液壓可能會(huì)成為將來(lái)的最好選擇。 （3）液壓的需要 在一些領(lǐng)域，例如金礦開(kāi)采，事物和藥品生產(chǎn)，水提供工業(yè)等等，這些由于油或者化學(xué)添加劑從液壓系統(tǒng)中泄露而弄臟產(chǎn)品或是損害大批產(chǎn)品的質(zhì)量，在這些條件下，自然水是一種理想的壓力介質(zhì)。 （4）經(jīng)濟(jì)的需要 水在很多地方都是存在的，不需要購(gòu)買、運(yùn)輸、貯存、保持和清理成本，因此使用水代替礦物油和其他液壓流體可以提供極大的經(jīng)濟(jì)性。在包圍的水環(huán)境中，系統(tǒng)使用自然水作為液壓流體能夠被設(shè)計(jì)成開(kāi)式循環(huán)。那意味著返回線和水儲(chǔ)藏可以消除，加熱和冷卻系統(tǒng)也不再需要了，因此液壓設(shè)備的容積和重量也會(huì)減少而系統(tǒng)的效率會(huì)增加。如果水下作業(yè)，例如在海運(yùn)的工程上，海洋探索工程，海底設(shè)備，水下操作工具和機(jī)器人等等，水液壓能夠自動(dòng)的抵消水靜力的前端，這對(duì)于提高效率和液壓系統(tǒng)的性能是很重要的。 （5）新應(yīng)用的需要 隨著現(xiàn)代科學(xué)和技術(shù)的發(fā)展，許多有著特殊需求的領(lǐng)域?yàn)樗簤禾峁┝撕芏噙\(yùn)用的機(jī)遇。例如在核電工程中的核聚變反應(yīng)裝置，在海洋探索工程中的海運(yùn)設(shè)備和機(jī)器人等等，這些地方需要考慮抗燃性，清潔的設(shè)備，經(jīng)濟(jì)性和環(huán)保等方面。和其它的能源轉(zhuǎn)換相比，由于液壓系統(tǒng)有較高的力密度和較小的尺寸，所以對(duì)于水液壓的應(yīng)用是迫切需要的。新應(yīng)用的需要是水液壓的出現(xiàn)和發(fā)展的內(nèi)在反應(yīng)。 3．材料選擇 滑動(dòng)部分/旋轉(zhuǎn)羅盤部分是軸向活塞泵和電動(dòng)機(jī)中的重要摩擦部分。在自然水的潤(rùn)滑下，巧妙地選擇材料是有必要的。 在一個(gè)典型的軸向活塞泵或電動(dòng)機(jī)中，旋轉(zhuǎn)羅盤固定不動(dòng)的，旋轉(zhuǎn)羅盤與軸線的角度決定了活塞盤的長(zhǎng)度。 當(dāng)使用自然水作為潤(rùn)滑劑時(shí)，由于自然水的化學(xué)活性自然，低粘性，潤(rùn)滑性差和較高的蒸汽壓力，所以需要考慮很多問(wèn)題。 首先，自然水，尤其海水是活性的，海水中的大量離子導(dǎo)致海水有很強(qiáng)的導(dǎo)電性并且會(huì)導(dǎo)致電化學(xué)腐蝕。用在滑塊和旋轉(zhuǎn)羅盤上的材料會(huì)不可避免地遭到自然水的活性腐蝕，并且用于傳統(tǒng)油液壓器件也不適合用在這里。 第二點(diǎn)，水的運(yùn)動(dòng)粘性在50℃時(shí)接近0.55cs，少于典型礦物油液體粘性的1/30。過(guò)低的粘性一定會(huì)增加發(fā)展滑塊和旋轉(zhuǎn)羅盤之間水力薄層的困難程度，并且水的粘性伴隨著壓力的很小變化意味著硬質(zhì)材料的流體動(dòng)力潤(rùn)滑是不容易發(fā)生的。帶有添加劑的液壓流體使得金屬與金屬表面之間沒(méi)有大量表面破壞或是磨損。自然水不包含如此多的添加劑并且它的潤(rùn)滑性是很差的。水的潤(rùn)滑性差很明顯是它的一個(gè)主要缺點(diǎn)，并且會(huì)導(dǎo)致接觸、破碎、和接觸器件之間摩擦的加劇。事實(shí)上摩擦是早期用水作為軸向活塞泵的流體的使用者遇到的最大問(wèn)題。研究表明水的流體彈性動(dòng)力薄層在3m/s和20~60℃時(shí)大約是0.1μm厚，HWBF的流體彈性動(dòng)力薄層在0.19~1.27m/s和23.5℃時(shí)大約是0.15μm厚。因此在自然水潤(rùn)滑下，滑塊和旋轉(zhuǎn)羅盤之間有干摩擦和強(qiáng)烈摩擦?xí)r會(huì)存在危險(xiǎn)。 第三點(diǎn)，水的蒸汽壓力要比礦物油的高很多，這意味著水沸騰或是蒸發(fā)會(huì)更加容易。由于水的高蒸汽壓力和高速流動(dòng)性由水的粘性地決定的，所以滑塊和旋轉(zhuǎn)羅盤會(huì)受到強(qiáng)烈和快速的氣穴氣蝕損害。 因此，對(duì)于滑塊和旋轉(zhuǎn)羅盤部分材料的選擇應(yīng)該依據(jù)工作條件和自然水的特殊性質(zhì)?；瑝K和旋轉(zhuǎn)羅盤之間的連接部分應(yīng)該有很好的機(jī)械強(qiáng)度、低摩擦、抗腐蝕性、和氣穴氣蝕、磨損和滑動(dòng)摩擦，并且應(yīng)該有很好的實(shí)用性和低成本。 4.結(jié)構(gòu)設(shè)計(jì) 滑塊的結(jié)構(gòu)設(shè)計(jì)和材料的選擇是同樣重要的。 用在滑塊上的高分子材料會(huì)產(chǎn)生一個(gè)新的問(wèn)題，就是怎樣使滑塊包圍住活塞前端的球形部分。其中一個(gè)解決辦法就是使用抗腐蝕材料與高分子材料連接?；瑝K可以分成兩部分。一部分就是由高分子材料制成的滑塊墊，直接與旋轉(zhuǎn)羅盤相連，他的主要的功能就是使滑塊有很好的摩擦性能。另一部分是由抗腐蝕的合金材料制成的鞋，它的主要功能是使滑塊在活塞的球形頭上摩擦。這個(gè)結(jié)構(gòu)能夠很好的利用金屬的展延性和高分子材料的摩擦性。（見(jiàn)圖2） 在滑塊上的主要的靜力在圖3中有表示?；瑝K上的力F來(lái)自活塞頭，包括活塞尾端的液體壓力Fp，反彈力Fs, 活塞和滑塊的慣性力Fa,還有活塞與圓孔之間的摩擦力Ff。 來(lái)自旋轉(zhuǎn)羅盤的反作用力N能夠被分成兩部分液壓軸承力Nh和機(jī)械表面壓力Nm，如下所示：N=Nh+Nm N和F的關(guān)系是：F=N·cosα 5.結(jié)論 根據(jù)作者的研究，一些關(guān)于滑塊在自然水潤(rùn)滑下的材料選擇和結(jié)構(gòu)設(shè)計(jì)結(jié)論可以總結(jié)為如下幾條： （1） 用高分子材料制作成的滑塊與用抗腐蝕性合金制成的旋轉(zhuǎn)羅盤結(jié)合有很好的摩擦性。 （2） 在滑塊的大量制造中棉布纖維填充的酚醛塑料被使用，目的是使工作壓力低于14MPa。 （3） 在滑塊上的反彈力應(yīng)該足夠強(qiáng)以確?；瑝K和旋轉(zhuǎn)羅盤表面上的連接壓力在0.1~0.2MPa。 除此之外還有一些實(shí)驗(yàn)需要進(jìn)行，并且擁有良好韌性的陶瓷材料也會(huì)被引進(jìn)用來(lái)大量制造滑塊和旋轉(zhuǎn)羅盤。在滑塊研究上的經(jīng)驗(yàn)將會(huì)為自然水液壓軸向活塞泵和電動(dòng)機(jī)的設(shè)計(jì)和發(fā)展提供很大的幫助。 參考文獻(xiàn)： [1] Joseph L. Foszcz, Hydraulic Fluid Choices, Plant Engineering, (8),1996,68. [2]Li Zhuangyun, et al, Development of Hydraulic Pump to Operate with Raw water, Proceedings of ASME Fluid Engineering Division Summer Meeting, Washington DC, USA, June 21-25,1998. [4]吳仁榮，水潤(rùn)滑滑動(dòng)軸承的設(shè)計(jì)計(jì)算，機(jī)電設(shè)備，（6），1997,30. [5]許耀銘，油膜理論與液壓泵和馬達(dá)的摩擦副設(shè)計(jì)，北京；機(jī)械工業(yè)出版社，1987.