草坪播種機的設計

喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預覽哦。下載后都有，請放心下載，文件全都包含在內，圖紙為CAD格式可編輯，【有疑問咨詢QQ:414951605 或 1304139763】 畢業(yè)設計說明書中文摘要草坪播種機的設計摘要 本設計是根據(jù)國內外播種機的發(fā)展趨勢，通用性和適應性不斷提高以及本著結構簡單操作靈活的原則，而設計的一種由地輪驅動的離心式草坪播種機。該機結構上優(yōu)點，使之能適應各種草地的播種。小到1-2分大的草地，大到十幾畝的草地都能適應。還可以根據(jù)草地的不同情況，調節(jié)合適的播種量。該播種機無引擎驅動，無噪音污染，播種效率高，輕便簡潔，操作方便，美觀實用，適用于一般草坪的播種。本文著重對播種機增速器、撒種部分以及葉輪等結構進行設計選擇。關鍵詞 草坪播種 播種機 播種 葉輪畢業(yè)設計說明書外文摘要The Design Of The Lawn SeederAbstract The design is based on the development trend of the machine, and constantly improve the universality and adaptability with simple structure, flexible operation, and design principle of a kind of ground wheel drive centrifugal lawn seeder. This machine structure, the advantages of the seeding can adapt to the grass. Small to 1-2 points in the big big to ten acres of grass, grass can adapt. According to the different grass can adjust suitable sowing rates.This machine is driven suif, engine, high efficiency, the pollution of portable concise, easy operation, beautiful and practical. Applicable to general lawn sowing. This paper machine, plate and seed growth structure design selection of impeller.Keywords Grass seeds Seeder Sow Impeller學士學位論文（設計）原創(chuàng)性聲明本人鄭重聲明：所提交的學位論文，是本人在導師指導下，獨立進行研究工作所取得的成果。除文中已注明引用的內容外，本論文不包含任何其他個人或集體已經(jīng)發(fā)表或撰寫過的作品成果。對本文研究做出過重要貢獻的個人和集體，均已在文中以明確方式標明。本人完全意識到本聲明的法律后果由本人承擔。學位論文作者簽名（親筆）： 年 月 日- 學士學位論文（設計）版權使用授權書專業(yè)： 論文（設計）題目：本學位論文作者完全了解學校有關保留、使用學位論文的規(guī)定，本科生在校攻讀期間學位論文（設計）工作的知識產(chǎn)權單位屬山西農(nóng)業(yè)大學，同意學校保留并向國家有關部門或機構送交論文的復印件和電子版，允許論文被查閱和借閱；本人授權山西農(nóng)業(yè)大學可以將學位論文的全部或部分內容編入有關數(shù)據(jù)庫進行檢索，可以采用影印、縮印或掃描等復制手段保存、匯編學位論文。畢業(yè)后發(fā)表與本研究有關的文章，作者單位署名應為“山西農(nóng)業(yè)大學”，可以在備注中注明本人現(xiàn)工作單位。本研究成果的知識產(chǎn)權歸屬山西農(nóng)業(yè)大學，未經(jīng)指導教師和山西農(nóng)業(yè)大學同意。本人不私自從事與課題有關的任何開發(fā)和盈利性活動。學位論文作者簽名（親筆）： 年 月 日導師簽名（親筆）： 年 月 日畢業(yè)設計評價表指導教師意見 簽 字： 年 月 日評閱人意見 簽 字： 年 月 日答辯委員會意見 主任委員簽字： 年 月 日院學術委員會意見 院長簽字： 年 月 日目 錄1 引 言12 技術任務書（JR）22.1 設計的依據(jù)22.2 產(chǎn)品的用途及使用范圍22.3 主要技術指標和重要技術參數(shù)22.4 主要工作原理32.5 已經(jīng)考慮過的若干方案的比較32.6 關鍵問題及其解決辦法42.7 機構的功能及特點53 設計計算說明書 （SS）53.1 草坪播種機結構的方案設計53.1.1 傳動比的確定53.1.2 動力參數(shù)計算63.2 圓錐齒輪的設計計算63.2.1 選擇材料，熱處理方式及精度等級63.2.2 按齒面接觸疲勞強度設計73.2.3計算齒輪的主要尺寸83.2.4驗算輪齒彎曲疲勞強度93.3 軸的設計計算103.3.1軸的設計103.3.2 軸的設計133.4 葉輪的設計163.4.1 結構尺寸設計163.4.2 驅動葉輪所需功率L173.5 地輪的構造183.6 零件的設計計算183.6.1 絲桿的設計183.6.2 鍵連接的選擇及計算194 使用說明書（SM）194.1 使用前注意事項194.2 播種時應注意的事項195 標準化審核報告（BS）205.1 產(chǎn)品圖樣的審查205.2產(chǎn)品技術文件的審查205.3 標注件的使用情況205.4 審查結論216 結 論216.1 機構的創(chuàng)新點216.2 制造價格及應用范圍21參 考 文 獻22致 謝23山西農(nóng)業(yè)大學工程技術學院畢業(yè)設計說明書1 引 言時間轉瞬即逝，轉眼之間四年的大學生涯就要結束了，回首四年的學習生活，我感到自己的收獲無比豐富。四年來，我不僅認真學習了各門基礎課，而且更加系統(tǒng)地掌握了多門專業(yè)技術課，在每次的課程設計中，我都認真對待，努力鉆研。這樣，通過四年的鍛煉不斷地提高了我的設計、繪圖、識圖能力。可以說，大學里的理論基礎，不但使我學會了分析問題、解決問題的能力，而且更強化了我的知識結構。尤其幸運的是，我不只一次地深入工廠實習，把學到的知識應用于實習現(xiàn)場的具體工作中，提高了自己的動手能力，為我今后步入工作崗位打下了更好的實踐基礎。 本次設計的目的是培養(yǎng)自己初步掌握獨立從事專業(yè)技術工作的能力，提高自己從事工藝和工藝裝備設計的水平，使我初步掌握從事本專業(yè)科學研究工作的能力。通過畢業(yè)設計不但培養(yǎng)了我運用各種工具書的方法和技巧，同時也培養(yǎng)了我獨立思考問題、解決問題的能力。通過翻閱查找各種工具書，擴大了視眼，豐富了自己的知識范圍。 本次設計我是有充分準備的。我不僅準備了四年的時間來掌握各門專業(yè)課學習，而且我多次深入工廠實習，更主要的是設計期間不斷地從網(wǎng)上、圖書館收集大量的資料，尋找各種解決問題的方法。所以說本設計我是有充分準備的，它是與生產(chǎn)實際相結合。它也將成為我走上工作崗位的一次重要演習，為我今后的工作打下堅實的基礎。 草坪播種機設計是一個典型的機械系統(tǒng)設計。 提高農(nóng)業(yè)的機械化和自動化程度，是實現(xiàn)農(nóng)業(yè)現(xiàn)代化的重要一環(huán)。用現(xiàn)代化設備裝備我國農(nóng)業(yè)工廠，已成為一項迫切的重要任務。 實現(xiàn)草坪播種作業(yè)機械化的好處：節(jié)約勞動力，提高生產(chǎn)率和草坪質量，節(jié)約原材料和降低成本，降低勞動強度和改善環(huán)境衛(wèi)生，保證操作的安全，減少草籽的浪費等。草坪播種作業(yè)機械化、自動化目前正向著高速化、通用性、可靠性、費用低、流水線自動化控制、采用新的機械工具等六個方向發(fā)展。 2 技術任務書（JR）2.1 設計的依據(jù)目前在我國已有專用草坪播種機械, 但是價格很高。通常對于播種面積不算太大, 又不是專業(yè)經(jīng)營草坪種植業(yè)的單位或個人, 就沒有必要專門買一臺草坪播種機, 這樣就給草坪播種帶來很大的困難。為了解決這一問題, 經(jīng)過多次對市場調查和研究, 決定設計一種簡易草坪播種機。2.2 產(chǎn)品的用途及使用范圍草坪是高度培育的特殊草地, 隨著草坪面積的擴大, 品質的提高, 草坪業(yè)逐漸由單一的人工作業(yè)向半機械化、機械化、自動化過渡, 草坪作業(yè)的機械化已成為十分重要的課題。專用的草坪播種機還處于起步階段, 草坪草種子細小,用手撒的方法不僅不易將種子撒勻, 且工作效率低, 不能滿足建坪建設的要求。 通過市場調研，決定設計一種由地輪驅動的離心式草坪播種機，該機由種子箱、機架、傳動裝置、葉輪等部分組成, 一人即可操作, 播種者雙手推動播種機，種子箱下的旋轉葉輪便會把種子吹出去, 下種口的大小可調, 播種量的多少調節(jié)下種速度。此播種機體積小、質量輕、結構簡單、靈活耐用, 不受地形、環(huán)境和氣候的影響, 不僅適用于大面積建坪, 更適用于在復雜的場地下建坪使用。2.3 主要技術指標和重要技術參數(shù)計劃設計播種機的主要設計參數(shù)：1） 外形尺寸：519mm380mm800mm2） 功率：417W3） 輪子轉速：64r/min4） 力矩：=62224Nmm5） 凈質量：40kg6） 變速要求：單級7） 葉輪半徑：0.1m2.4 主要工作原理本次設計的手推式播種機主要利用輪子運動傳動變速箱中的錐齒輪實現(xiàn)飛輪的高速運動的功能。播種機工作時由人推動機器行走，驅動地輪帶動安裝在齒輪箱內的一對錐齒輪轉動，固定在被動錐齒輪軸上的葉輪在錐齒輪的驅動下高速旋轉。種子箱內的種子靠重力通過種子箱底部的落種口經(jīng)過絲桿和圓錐下料筒下落到轉動的葉輪邊緣，在葉輪風力的作用下撒布于地表。在被動錐齒輪軸伸入種子箱底部的端頭，安裝有攪種裝置，可將種子順利落入撒種盤。撒種量可通過改變落種口開度來調節(jié)。2.5 已經(jīng)考慮過的若干方案的比較我所設計的手推式草坪播種機首先要通過一個傳力構件將人力傳遞出去。為了讓操作者在正常行走速度下操作，傳遞出去的力應通過增速機構繼續(xù)傳遞。因執(zhí)行播種動作的葉輪的相對運動方向與人行進的方向垂直，經(jīng)前面增速機構傳遞過來的運動都需要再經(jīng)過一級轉換機構傳遞到執(zhí)行構件。通過分析得到手推式草坪剪草機的組成框圖，如圖21所示。圖21手推式草坪剪草機的組成框圖能實現(xiàn)草坪播種的方法較多，但各有利弊，具體分析如下：（1）用手撒 草坪草種子細小，用手撒的方法不僅不易將種子撒勻, 且工作效率低, 不能滿足建坪建設的要求。（2）用鐵篩撒 用鐵篩雖然避免了用手撒的弊端，但浪費時間，且人力消耗量大，不能滿足一般草坪的建設要求。（3）用播種機 用播種機，可避免以上兩種方法存在的問題，使所設計的機器小巧，且可靈活操作。因此，我們選擇設計手動式播種機。手動的形式又有手搖動和用手推動兩種。機械容易實現(xiàn)的是簡單的轉動和往復直線運動，如果用手搖動手柄實現(xiàn)執(zhí)行構件的往復移動，由于播種機還要靠人力推著向前行進，操作者要完成的動作過多，操作不方便。要使操作者只通過簡單的操作即可完成播種動作，可以用手推播種機向前行駛，靠播種機輪子的轉動將轉動運動轉變成葉輪的往復旋轉而輸出到執(zhí)行構件。顯然設計成手動式草坪剪草機是合理而可行的。2.6 關鍵問題及其解決辦法增速機構的設計：用組合法實現(xiàn)增速為了讓操作者在正常行走速度下操作，傳遞出去的力應通過增速機構繼續(xù)傳遞。由于轉換機構的運動輸入構件作定軸轉動，這樣在播種機動力輸入構件輪子和轉換機構的運動輸入構件之間，可以采用鏈傳動，帶傳動和齒輪傳動。為了使所設計的剪草機結構緊湊，可以采用齒輪傳動。而齒輪傳動有直齒圓柱齒輪傳動，斜齒圓柱齒輪傳動，直齒錐齒輪傳動和蝸輪蝸桿傳動等。但是蝸輪蝸桿傳動的效率低，一般是蝸桿主動，且軸線空間交錯，應用到播種機械中，會使支撐結構復雜。直齒圓柱齒輪傳動和斜齒圓柱齒輪傳動的軸線相互平行，不能起到兩軸垂直的作用，因此，可選擇直齒錐齒輪傳動作為增速機構。機構組成方案如圖22所示。 圖2-2 機構簡圖2.7 機構的功能及特點（1） 該機采用地輪齒輪傳動結構，結構緊湊，體積小，質量輕，噪音小、無污染，使用方便、靈活，適合一般草坪的播種；（2） 無需引擎驅動，使用安全、可靠，便于維護；（3） 播種幅寬為1m，外形尺寸（長寬高：586369200mm）,質量40kg（材料由45鋼制作）；（4） 采用耐用的鑄鋁底盤和結構件，具有永不生繡、永不卷曲變形的特點；（5） 地輪半徑為0.25m，且一個輪子裝上壽命長的球軸承，使播種機轉彎時易于推動；（6） 金屬手柄易于折疊，以減少包裝尺寸，手柄長度可伸縮，對于不同身高的操作者同樣適用；（7） 撒種部分獨特的設計可防止種子堵塞出口通道；（8） 外觀造型美觀，更適合家庭用戶的審美要求；（9） 播種的效果較理想，且成本低，是一般草坪播種的首選產(chǎn)品。 3 設計計算說明書 （SS）3.1 草坪播種機結構的方案設計3.1.1 傳動比的確定根據(jù)運動學基本原理，在忽略種子與撒種盤之間摩擦的情況下，傳動比為： （1）式中 Rd-地輪半徑 D-撒種幅寬 r-撒種盤半徑 v-行走速度 H-撒種盤離地高度 g-重力加速度在確定行走速度v時，既要保證播種機在種子箱裝滿種子后，播種機能夠正常作業(yè)，又要保證機組有較高的作業(yè)生產(chǎn)率，以速度v=6km/h來設計；考慮到我國一般草坪地塊面積小，幅寬窄的特點，撒種幅寬D設計為1m，設計參數(shù)Rd=0.25m，r=0.1m，H=0.55m。則按式（1）計算出地輪驅動離心式播種機所需的傳動比i=3。 3.1.2 動力參數(shù)計算草籽較輕，容易甩出，不需要過大的載荷，故假設人的推力為F=250N，所以兩個地輪上所受力的大小為：F1=F2=125N地輪提供轉矩帶動撒種盤進行機械運動，假定撒種盤所受的力全部來自地輪。則：P輪=Fv=417W地輪轉速：n=64r/min 初選8級精度直齒錐齒輪 滾動軸承（球軸承） 齒輪傳動軸承（滾子軸承） 傳動機構總效率：0.950.9920.98=0.903軸上的所傳遞的功率大小為：=4170.99=413(W)軸上的所傳遞的功率大小為：=4130.950.98=396(W)軸上的轉速大小為：=147.69(r/min)軸上的轉速大小為：=443.09(r/min)3.2 圓錐齒輪的設計計算圓錐齒輪的設計直齒錐齒輪加工多為刨齒，不宜采用硬齒面，計算步驟如下：3.2.1 選擇材料，熱處理方式及精度等級（1）齒輪材料。熱處理方式由參考文獻1表6-7和表6-8并考慮HBS1=HBS2+（3050）HBS的要求，小齒輪選用40Cr，調質處理，齒面硬度241286HBS，大齒輪選用42SiMn鋼，調質處理，齒面硬度217255HBS。（2）精度等級。估計圓周速度不大于3m/s，根據(jù)參考文獻1表6-5，初選8級精度。3.2.2 按齒面接觸疲勞強度設計1）確定公式中的各參數(shù)值（1）選齒數(shù)。小齒輪齒數(shù)z1=24,z2=uz1=72（2）確定極限應力，由參考文獻1圖6-32，按齒面硬度中間值260HBS，查得小齒輪。由參考文獻1圖6-32，按齒面硬度中間值230HBS查得大齒輪。（3）確定壽命系數(shù)ZN。由題意可知：ZN1=ZN2=1。（4）許用應力由參考文獻1表6-9查得，SHmin=1。由參考文獻1式（6-20）得 （5）載荷系數(shù)K?？紤]錐齒輪是懸臂布置，由參考文獻1表6-10取K=1.2。（6）計算小齒輪傳遞的轉矩T1 （7）齒寬系數(shù)。取。（8）節(jié)點區(qū)域系數(shù)。（9）確定材料系數(shù)。由參考文獻1表6-11查得。2）計算和（1）小輪大端分度直徑 （2）小齒輪齒寬中點的分度圓直徑 （3）圓周速度： 故8級精度合適。3.2.3計算齒輪的主要尺寸1）模數(shù) 圓整取。2）實際大端分度圓直徑 3）錐距 4）齒寬 5）分度圓錐角和 ， 6)當量齒數(shù) 3.2.4驗算輪齒彎曲疲勞強度（1）確定極限應力。由參考文獻1圖6-34，按齒面硬度中間值260HBS，查得小齒輪，由參考文獻1圖6-34，按齒面硬度中間值230HBS，查得大齒輪。（2）確定壽命系數(shù)YN1和YN2,由題意可知：YN1 =YN2=1。（3）確定最小安全系數(shù)。查參考文獻1表6-9得。（4）確定許用應力。 （5）復合齒形系數(shù)和。查參考文獻1表6-12得 ，（6）計算彎曲應力： 所以齒輪彎曲強度足夠。3.3 軸的設計計算3.3.1軸的設計（1）選擇軸的材料該軸無特殊要求，選擇45鋼調質處理，=640MPa（2）初步估算軸徑按扭轉強度估算輸入端的最小軸徑。按45鋼，取C=116根據(jù)公式，此軸頭上有一鍵槽，將軸徑增大5%，即dmin=（16.341.05）mm=17.15mm,取dmin=18mm（3）軸的結構設計1）軸上零件的軸向定位 大齒輪在軸上為對稱定位，左右兩端靠套筒定位，裝拆，傳力較為簡單；兩端軸承常用同一尺寸，以便于加工、安裝和維修；為便于拆裝軸承，軸承處軸肩不宜太高。 2）軸上零件的周向定位 齒輪與軸的軸向固定采用普通平鍵聯(lián)接。根據(jù)軸的直徑查得齒輪處的鍵截面尺寸為，配合為，滾動軸承內圈與軸的配合采用基孔制。 確定各段軸徑和長度通過確定定位軸肩高度，從左輪子連接處向右取。 考慮軸的結構工藝性考慮到軸的結構工藝性，在軸的左端和右段均制成倒角 （4）軸的強度演算 經(jīng)結構設計之后，各軸段作用力大小和作用點位置、軸承跨距、各段軸徑等參數(shù)均已知。1) 齒輪上作用力的大小轉矩：=62224Nmm齒輪端面分度圓直徑： 圓周力：徑向力：軸向力：受力簡圖5-1所示： 圖3-1垂直面上受力簡圖2）求垂直面上軸承的支反力及主要截面的彎矩 截面C處的彎矩為：(Nmm)(Nmm) 圖3-2垂直面上截面的彎矩3） 求水平面上軸承的支反力及主要截面的彎矩：截面C處的彎矩為：(Nmm) 圖3-3水平面上截面的支反力4） 截面C處垂直面和水平面的合成彎矩為：(Nmm) (Nmm)圖3-4水平面上截面的彎矩及合成彎矩5）按彎扭合成應力校核軸的強度進行校核時，通常只校核軸上承受最大彎矩和扭矩的截面強度，取該截面上的計算應力：通過查表可知：材料為45鋼，調質處理的許用應力為，由于，故安全。3.3.2 軸的設計（1）選擇軸的材料該軸無特殊要求，選擇45鋼調質處理，=640MPa（2）初步估算軸徑按扭轉強度估算輸入端的最小軸徑。按45鋼，取C=116根據(jù)公式，此軸頭上有一鍵槽，將軸徑增大5%，即dmin=（11.171.05）mm=11.72mm,取dmin=12mm（3）軸的結構設計1）軸上零件的軸向定位 小齒輪在軸上為對稱定位，上下兩端靠套筒定位，裝拆，傳力較為簡單；兩端軸承常用同一尺寸，以便于加工、安裝和維修；為便于拆裝軸承，軸承處軸肩不宜太高。 2）軸上零件的周向定位 齒輪與軸的軸向固定采用普通平鍵聯(lián)接。根據(jù)軸的直徑查得齒輪處的鍵截面尺寸為，配合為，滾動軸承內圈與軸的配合采用基孔制。 確定各段軸徑和長度通過確定定位軸肩高度，從上向下取。 考慮軸的結構工藝性考慮到軸的結構工藝性，在軸的左端和右段均制成倒角 （4）軸的強度演算 經(jīng)結構設計之后，各軸段作用力大小和作用點位置、軸承跨距、各段軸徑等參數(shù)均已知。2) 齒輪上作用力的大小轉矩：=19310.18 Nmm 齒輪端面分度圓直徑： 圓周力：徑向力：軸向力： 圖3-5軸垂直面上受力簡圖2）求垂直面上軸承的支反力及主要截面的彎矩 截面C處的彎矩為：(Nmm)(Nmm)圖3-6軸垂直面上截面的彎矩3)求水平面上軸承的支反力及主要截面的彎矩：截面C處的彎矩為：(Nmm)圖3-7軸水平面上截面的支反力4)截面C處垂直面和水平面的合成彎矩為：(Nmm) (Nmm)圖3-8軸水平面上截面的彎矩及合成彎矩5)按彎扭合成應力校核軸的強度進行校核時，通常只校核軸上承受最大彎矩和扭矩的截面強度，取該截面上的計算應力：通過查表可知：材料為45鋼，調質處理的許用應力為，由于，故安全。3.4 葉輪的設計選擇材料：因為草籽質量輕，材料無特殊要求，選用45號剛調質處理，葉片厚度1mm，制造上多采用整體鑄造結構和分體鉚接或焊接等工藝方法來實現(xiàn)，這也是由其結構特點所決定的。3.4.1 結構尺寸設計 圖6-1葉輪形式如圖所示，離心風機的主要結構參數(shù)如下。葉輪外徑, 常用D表示；葉輪寬度, 常用b表示；葉輪出口角,一般用表示。葉輪按葉片出口角的不同可分為三種:前向式葉片彎曲方向與旋轉方向相同, 90(90 160)；后向式葉片彎曲方向與旋轉方向相反, 90(20 70)；徑向式葉片出口沿徑向安裝,= 90。 根據(jù)播種機行走速度和撒籽幅寬，初設葉輪直徑D1=20cm，葉片數(shù)Z按經(jīng)驗公式估計：Z=D1為葉輪外徑，單位厘米。所以葉片數(shù)取6片。葉片傾角 3.4.2 驅動葉輪所需功率L 當葉片數(shù)目有限時，由于流體流動方向的變化，葉片理論壓頭公式為： （1）式中：Hth為葉輪壓頭；u為圓周速度；v為徑向速度。飛輪對氣體作功： （2）式中：k為多變系數(shù)；R為氣體常數(shù)；G為輸送的流體總量；n為多變指數(shù)；TT0為入口全溫；為容積效率。設葉輪入口處風速為v1m=16m/s，=0.75，則入口全溫：由（2）式：3.167(KW)4.22(KW)如果葉輪的效率=0.54，則軸功率：Ls=Lt/0.54=7.81(KW)由,得293K時氣體重度，故驅動葉輪所需軸功率L為：0.3338(KW)，故符合設計功率。3.5 地輪的構造 地輪由兩個個直徑為50cm 的小車輪及其連桿組成。兩個地輪是由長軸的兩端按軸的垂直方向各焊有一對長13cm的平行小鐵板來固定, 小鐵板下端有固定行走輪軸的陷口, 使地輪固定。長軸被套在大三角鐵后面的兩個寬鐵環(huán)內, 長軸上設有凸出物使得長軸在寬鐵環(huán)內只能轉動, 不能左右串動。在長軸的中間, 對準雙桿手柄的一個級桿處, 在長軸上焊有一個長75cm 的單鐵桿柄, 其方向與長軸兩端的兩平行小鐵板恰好反方向，使人推上播種機能夠順利行走。3.6 零件的設計計算在該播種機上所用的一些附件都是一些標準件，它們一共有絲桿、鍵和墊圈。3.6.1 絲桿的設計此絲桿受力不大，無特殊要求，選用45號鋼。熱處理：調質HB220-270，高頻淬火HRC45-48。因為絲桿直徑已經(jīng)標準化，所以在設計絲桿時，直徑不能任意確定。我國所規(guī)定的絲桿直徑系列為：30，45，65，（85）90，（115）120，150，200。一般情況下，確定的絲桿直徑應符合此系列。故，選用絲桿直徑為30mm。螺旋角：物料為草籽，選用=30絲桿螺槽深度：h=0.2D=6mm絲桿與套筒間隙的確定：=（0.003-0.005）D，取=0.005D=0.15mm3.6.2 鍵連接的選擇及計算中間軸和齒輪用鍵聯(lián)接的選擇和強度校核 齒輪與軸的鍵聯(lián)接 選用圓頭普通平鍵（型）按軸徑d=20mm及輪廓長l=78mm,查表14-1,選鍵1870GB1096-79.強度校核 鍵材料用45鋼，查表得許用應力，鍵的工作長度，按公式得擠壓應力：雖然略大于，但齒輪與軸是采用過盈配合，靠聯(lián)接擦力傳遞部分轉矩，故聯(lián)接的強度是足夠的。4 使用說明書（SM）4.1 使用前注意事項播種機在路上行走時， 可將離合器拉起,，使被動軸與主動軸分開，只有兩個地輪著地，這樣便于遠距離和播過種的區(qū)域的行走。如果需要播種，在被播地段上，將離合器拉下，兩軸自然結合，然后開始播種。如果播種籽量不適宜，可調節(jié)下種口大小，在小范圍內調整播種量。播種后出苗特征為：苗幅寬為4cm 左右，兩苗幅間寬為56cm 左右，這樣出苗后24 個月便可長滿苗幅間空處。4.2 播種時應注意的事項（1）草坪床應疏松，表層不能有過大的石塊或大的硬土塊及其他草根類雜物。（2）草坪床應該盡量平整，坡度不能過大。5 標準化審核報告（BS）5.1 產(chǎn)品圖樣的審查手推式草坪播種機的傳動裝置和葉輪風扇的設計已經(jīng)基本完成，現(xiàn)以具備全套圖紙和一線基本數(shù)據(jù)，根據(jù)有關規(guī)定，對其進行標注化審查，結果如下： （1） 產(chǎn)品的圖樣完整、統(tǒng)一、表達準確清楚、圖樣清楚。符合GB4440-84、GB-83機械制圖的規(guī)定。（2） 產(chǎn)品圖樣公差與配合的選擇與標準符合GB/T1800、3-1998的規(guī)定。（3） 產(chǎn)品圖樣的編號符合JB/T5054.5-2000中華人民共和國機械行業(yè)標準產(chǎn)品圖樣及設計的完整性。（4） 圖紙的標題欄與明細欄符合GB/T10609. 1-1989GB/T10690. 2-1989的規(guī)定。（5） 產(chǎn)品圖樣粗糙度的標注符合GB131-83表面特征代號及注法的規(guī)定。（6） 產(chǎn)品圖樣焊縫的代號符合GB324-80焊縫代號的規(guī)定。5.2 產(chǎn)品技術文件的審查（1） 產(chǎn)品的技術文件名稱、術語符合ZB/TJ01和0351-90產(chǎn)品圖樣及設計文件術語及有關標準的規(guī)定。（2） 量和單位符合GB3100GB3102-93的規(guī)定。（3）技術文件所用的編碼符合JB/T8823-1998機械工業(yè)企業(yè)計算機輔助管理信息分類編碼導則的規(guī)定。（4）技術文件的完整性符合JB/T5054.5-2000產(chǎn)品圖樣及技術文件完整性的規(guī)定及農(nóng)機部門的有關具體要求。5.3 標注件的使用情況本設計所用的緊固件均采用標準的螺栓，材料及材料代號也符合國家標準和部頒標準的相關規(guī)定。5.4 審查結論經(jīng)過對播種機裝置和傳動設計的標準化審查，認為該設計基本貫徹了國家最新頒發(fā)的各種標準，圖紙和設計文件完整齊全，符合標準化得要求。6 結 論6.1 機構的創(chuàng)新點（1） 從機構運動的功能出發(fā)，按變異組合法和類比法完成機構的構件和設計;（2） 在作品樣機加工前，使用三維造型軟件進行三維造型、虛擬裝配和運動仿真，從理論上驗證設計的可行性，然后進行樣機制作；（3） 無引擎驅動，節(jié)省能源，無污染（噪音、廢氣），采用綠色環(huán)保設計；（4） 外觀造型新穎，推桿可折疊伸縮，適合家庭用戶使用；（5） 采用齒輪機構（實現(xiàn)增速），提高整機的工作效率，解決了手動播種機工作效率不高的問題；（6） 產(chǎn)品成本（制造和使用成本）低，符合廣大用戶購買能力的要求。6.2 制造價格及應用范圍根據(jù)目前市場實際:：制造原材料費用80120 元，手工費: 6080 元，因此總造價在200元以內。目前使用于我國大部分地區(qū)的一般建坪。參 考 文 獻1 吳偉，任紅英. 機械設計教程 M . 北京：北京理工大學出版社，2007.2 張祖立. 機械設計 M . 北京：中國農(nóng)業(yè)出版社，2004.3 吳宗澤，羅圣國. 機械設計課程設計手冊（第3版）M.北京：高等教育出版社，2006.4 張也影. 流體力學（第2版）M . 北京：高等教育出版社，2005.5 張良成. 材料力學 M . 北京：中國農(nóng)業(yè)出版社，20036 楊敏麗. 牧草生產(chǎn)機械化:西部農(nóng)業(yè)機械化發(fā)展J中國農(nóng)機化, 2000,(04)7 楊愛軍. 呼和浩特市地區(qū)農(nóng)業(yè)機械化現(xiàn)狀及發(fā)展對策J農(nóng)村機械化, 2004,(04)8 趙嶺,呂釗欽. 可靠性技術在農(nóng)業(yè)機械中的應用J山東農(nóng)機, 2004,(07)9 郭毅, 張祖立, 張旭東. 大蒜播種機械的研究現(xiàn)狀J. 農(nóng)機化研究, 2009, (06)10 高林. 育苗生產(chǎn)線氣吸式播種系統(tǒng)智能控制的研究D北京林業(yè)大學, 2008 . 11 劉文忠. 氣吸式排種裝置排種性能試驗研究D內蒙古農(nóng)業(yè)大學, 2008 .12 李濟賓. 播種機組行走的方法J. 河南農(nóng)業(yè), 1993, (04) 13 籍增順. 關于發(fā)展小雜糧的思考J. 山西農(nóng)業(yè)(村委主任), 2009, (04)14 夏俊芬. 旱作多功能精密穴播輪的研究D華中農(nóng)業(yè)大學, 200015 史智興. 精播機排種性能檢測系統(tǒng)及關鍵技術研究D中國農(nóng)業(yè)大學, 200216 濮良貴，紀名剛機械設計（第七版）S北京：高等教育出版社2001致 謝在設計過程中，得到了崔清亮老師的親切關懷和耐心的指導。崔老師多次詢問研究進程，并為我指點迷津，幫助我開拓研究思路，精心點撥、熱忱鼓勵。崔老師一絲不茍的作風，嚴謹求實的態(tài)度，踏踏實實的精神，不僅授我以文，而且教我做人，雖歷時半年，卻給以終生受益無窮之道。在次，我向崔老師表示忠心的感謝！我還非常感謝工程技術學院的老師們，在四年學習期間，他們不僅教給了我很多知識，使我從對機械一無所知成為具有初步機械學知識并且可以簡單應用的人，從只為自己的事情操心變成現(xiàn)在經(jīng)常看報紙，聽廣播，并關注國家大事，而且還教給了我做人的道理。對此我非常感謝！最后，由草坪播種機的復雜性和長期性，不是用一篇文章就能解決問題的，另外，由于我的經(jīng)驗匱乏、水平有限，本文錯誤和疏漏之處不少，請老師和同學們指正，謝謝！- 23 -山 西 農(nóng) 業(yè) 大 學本科生畢業(yè)論文（設計）選題審批表畢業(yè)論文（設計）題目草坪播種機的設計指 導 教 師崔清亮職 稱教 授學生具備條件修完教學計劃要求課程內容及學時選題完成形式開題報告內 容 簡 要：本設計是根據(jù)國內外播種機的發(fā)展趨勢，通用性和適應性不斷提高以及本著結構簡單操作靈活的原則，而設計的一種由地輪驅動的離心式草坪播種機。該機結構上優(yōu)點，使之能適應各種草地的播種。小到1-2分大的草地，大到十幾畝的草地都能適應。還可以根據(jù)草地的不同情況，調節(jié)合適的播種量。該播種機無引擎驅動，無噪音污染，播種效率高，輕便簡潔，操作方便，美觀實用，適用于一般草坪的播種。本文著重對播種機增速器、撒種部分以及葉輪等結構進行設計選擇。 系主任簽字： 年 月 日 院長簽字： 年 月 日2山西農(nóng)業(yè)大學本科生畢業(yè)設計開題報告題 目 草坪播種機的設計 學院名稱 信息學院 專業(yè)名稱 機械設計制造及其自動化年 級 2005級 學生姓名 胡艷虹 學 號 2005151215 指導教師 崔清亮 職 稱 教 授 2009年 3 月 25 日選題的依據(jù)及意義（包括課題的理論價值和實踐價值；國內外的研究概況等）：目前在我國已有專用草坪播種機械, 但是價格很高。通常對于播種面積不算太大, 又不是專業(yè)經(jīng)營草坪種植業(yè)的單位或個人, 就沒有必要專門買一臺草坪播種機, 這樣就給草坪播種帶來很大的困難。為了解決這一問題, 經(jīng)過多次對市場調查和研究, 決定設計一種簡易草坪播種機。草坪是高度培育的特殊草地, 隨著草坪面積的擴大, 品質的提高, 草坪業(yè)逐漸由單一的人工作業(yè)向半機械化、機械化、自動化過渡, 草坪作業(yè)的機械化已成為十分重要的課題。專用的草坪播種機還處于起步階段, 草坪草種子細小,用手撒的方法不僅不易將種子撒勻, 且工作效率低, 不能滿足建坪建設的要求。 通過市場調研，決定設計一種由地輪驅動的離心式草坪播種機，該機由種子箱、機架、傳動裝置、葉輪等部分組成, 一人即可操作, 播種者雙手推動播種機，種子箱下的旋轉葉輪便會把種子吹出去, 下種口的大小可調, 播種量的多少調節(jié)下種速度。此播種機體積小、質量輕、結構簡單、靈活耐用, 不受地形、環(huán)境和氣候的影響, 不僅適用于大面積建坪, 更適用于在復雜的場地下建坪使用。本課題研究內容 本設計研究的草坪播種機是一種由地輪驅動的離心式草坪播種機，該機由種子箱、機架、傳動裝置、葉輪等部分組成, 一人即可操作, 播種者雙手推動播種機，種子箱下的旋轉葉輪便會把種子吹出去, 下種口的大小可調, 播種量的多少調節(jié)下種速度。此播種機體積小、質量輕、結構簡單、靈活耐用, 不受地形、環(huán)境和氣候的影響, 不僅適用于大面積建坪, 更適用于在復雜的場地下建坪使用。本課題研究方案能實現(xiàn)草坪播種的方法較多，但各有利弊，具體分析如下：（1）用手撒 草坪草種子細小，用手撒的方法不僅不易將種子撒勻, 且工作效率低, 不能滿足建坪建設的要求。（2）用鐵篩撒 用鐵篩雖然避免了用手撒的弊端，但浪費時間，且人力消耗量大，不能滿足一般草坪的建設要求。（3）用播種機 用播種機，可避免以上兩種方法存在的問題，使所設計的機器小巧，且可靈活操作。因此，我們選擇設計手動式播種機。研究的創(chuàng)新之處（1） 無引擎驅動，節(jié)省能源，無污染（噪音、廢氣），采用綠色環(huán)保設計；（2） 外觀造型新穎，推桿可折疊伸縮，適合家庭用戶使用；（3） 采用齒輪機構（實現(xiàn)增速），提高整機的工作效率，解決了手動播種機工作效率不高的問題；（4） 產(chǎn)品成本（制造和使用成本）低，符合廣大用戶購買能力的要求。 研究過程(含完成期限)第一周與指導老師確定設計題目并制定詳細的設計要求；第二周調查、收集、研究現(xiàn)有資料，根據(jù)課題計劃任務書的要求，明確整個設計的任務和方向；第三周提出多種設計方案，通過分析對比，確定出最優(yōu)方案；第四和第五周以確定的初步方案繪制出原理圖或機構運動簡圖，確定機構組成和各種參數(shù)計算；第六和第七周詳細繪制總裝配圖、部件裝配圖和零件圖；第八周交由指導老師批改；第九周修改并完善設計指導教師意見 指導教師簽名：年 月 日教研室意見 教研室主任簽名：年 月 日院系意見 主管領導簽名： 年 月 日Design of machine and machine elementsMachine designMachine design is the art of planning or devising new or improved machines to accomplish specific purposes. In general, a machine will consist of a combination of several different mechanical elements properly designed and arranged to work together, as a whole. During the initial planning of a machine, fundamental decisions must be made concerning loading, type of kinematic elements to be used, and correct utilization of the properties of engineering materials. Economic considerations are usually of prime importance when the design of new machinery is undertaken. In general, the lowest over-all costs are designed. Consideration should be given not only to the cost of design, manufacture the necessary safety features and be of pleasing external appearance. The objective is to produce a machine which is not only sufficiently rugged to function properly for a reasonable life, but is at the same time cheap enough to be economically feasible. The engineer in charge of the design of a machine should not only have adequate technical training, but must be a man of sound judgment and wide experience, qualities which are usually acquired only after considerable time has been spent in actual professional work.Design of machine elements The principles of design are, of course, universal. The same theory or equations may be applied to a very small part, as in an instrument, or, to a larger but similar part used in a piece of heavy equipment. In no ease, however, should mathematical calculations be looked upon as absolute and final. They are all subject to the accuracy of the various assumptions, which must necessarily be made in engineering work. Sometimes only a portion of the total number of parts in a machine are designed on the basis of analytic calculations. The form and size of the remaining parts are designed on the basis of analytic calculations. On the other hand, if the machine is very expensive, or if weight is a factor, as in airplanes, design computations may then be made for almost all the parts. The purpose of the design calculations is, of course, to attempt to predict the stress or deformation in the part in order that it may sagely carry the loads, which will be imposed on it, and that it may last for the expected life of the machine. All calculations are, of course, dependent on the physical properties of the construction materials as determined by laboratory tests. A rational method of design attempts to take the results of relatively simple and fundamental tests such as tension, compression, torsion, and fatigue and apply them to all the complicated and involved situations encountered in present-day machinery. In addition, it has been amply proved that such details as surface condition, fillets, notches, manufacturing tolerances, and heat treatment have a market effect on the strength and useful life of a machine part. The design and drafting departments must specify completely all such particulars, must specify completely all such particulars, and thus exercise the necessary close control over the finished product. As mentioned above, machine design is a vast field of engineering technology. As such, it begins with the conception of an idea and follows through the various phases of design analysis, manufacturing, marketing and consumerism. The following is a list of the major areas of consideration in the general field of machine design: Initial design conception; Strength analysis; Materials selection; Appearance; Manufacturing; Safety; Environment effects; Reliability and life; Strength is a measure of the ability to resist, without fails, forces which cause stresses and strains. The forces may be; Gradually applied; Suddenly applied; Applied under impact; Applied with continuous direction reversals; Applied at low or elevated temperatures. If a critical part of a machine fails, the whole machine must be shut down until a repair is made. Thus, when designing a new machine, it is extremely important that critical parts be made strong enough to prevent failure. The designer should determine as precisely as possible the nature, magnitude, direction and point of application of all forces. Machine design is mot, however, an exact science and it is, therefore, rarely possible to determine exactly all the applied forces. In addition, different samples of a specified material will exhibit somewhat different abilities to resist loads, temperatures and other environment conditions. In spite of this, design calculations based on appropriate assumptions are invaluable in the proper design of machine. Moreover, it is absolutely essential that a design engineer knows how and why parts fail so that reliable machines which require minimum maintenance can be designed. Sometimes, a failure can be serious, such as when a tire blows out on an automobile traveling at high speeds. On the other hand, a failure may be no more than a nuisance. An example is the loosening of the radiator hose in the automobile cooling system. The consequence of this latter failure is usually the loss of some radiator coolant, a condition which is readily detected and corrected. The type of load a part absorbs is just as significant as the magnitude. Generally speaking, dynamic loads with direction reversals cause greater difficulties than static loads and, therefore, fatigue strength must be considered. Another concern is whether the material is ductile or brittle. For example, brittle materials are considered to be unacceptable where fatigue is involved. In general, the design engineer must consider all possible modes of failure, which include the following: Stress; Deformation; Wear; Corrosion; Vibration; Environmental damage; Loosening of fastening devices. The part sizes and shapes selected must also take into account many dimensional factors which produce external load effects such as geometric discontinuities, residual stresses due to forming of desired contours, and the application of interference fit joint. Selected from” design of machine elements”, 6th edition, m. f. sports, prentice-hall, inc., 1985 and “machine design”, Anthony Esposito, charles e., Merrill publishing company, 1975.Mechanical properties of materials The material properties can be classified into three major headings: (1) physical, (2) chemical, (3) mechanicalPhysical properties Density or specific gravity, moisture content, etc., can be classified under this category. Chemical propertiesMany chemical properties come under this category. These include acidity or alkalinity, react6ivity and corrosion. The most important of these is corrosion which can be explained in laymans terms as the resistance of the material to decay while in continuous use in a particular atmosphere. Mechanical properties Mechanical properties include in the strength properties like tensile, compression, shear, torsion, impact, fatigue and creep. The tensile strength of a material is obtained by dividing the maximum load, which the specimen bears by the area of cross-section of the specimen. This is a curve plotted between the stress along the This is a curve plotted between the stress along the Y-axis(ordinate) and the strain along the X-axis (abscissa) in a tensile test. A material tends to change or changes its dimensions when it is loaded, depending upon the magnitude of the load. When the load is removed it can be seen that the deformation disappears. For many materials this occurs op to a certain value of the stress called the elastic limit Ap. This is depicted by the straight line relationship and a small deviation thereafter, in the stress-strain curve (fig.3.1). Within the elastic range, the limiting value of the stress up to which the stress and strain are proportional, is called the limit of proportionality Ap. In this region, the metal obeys hookess law, which states that the stress is proportional to strain in the elastic range of loading, (the material completely regains its original dimensions after the load is removed). In the actual plotting of the curve, the proportionality limit is obtained at a slightly lower value of the load than the elastic limit. This may be attributed to the time-lagin the regaining of the original dimensions of the material. This effect is very frequently noticed in some non-ferrous metals. Which iron and nickel exhibit clear ranges of elasticity, copper, zinc, tin, are found to be imperfectly elastic even at relatively low values low values of stresses. Actually the elastic limit is distinguishable from the proportionality limit more clearly depending upon the sensitivity of the measuring instrument. When the load is increased beyond the elastic limit, plastic deformation starts. Simultaneously the specimen gets work-hardened. A point is reached when the deformation starts to occur more rapidly than the increasing load. This point is called they yield point Q. the metal which was resisting the load till then, starts to deform somewhat rapidly, i. e., yield. The yield stress is called yield limit Ay. The elongation of the specimen continues from Q to S and then to T. The stress-strain relation in this plastic flow period is indicated by the portion QRST of the curve. At the specimen breaks, and this load is called the breaking load. The value of the maximum load S divided by the original cross-sectional area of the specimen is referred to as the ultimate tensile strength of the metal or simply the tensile strength Au. Logically speaking, once the elastic limit is exceeded, the metal should start to yield, and finally break, without any increase in the value of stress. But the curve records an increased stress even after the elastic limit is exceeded. Two reasons can be given for this behavior: The strain hardening of the material; The diminishing cross-sectional area of the specimen, suffered on account of the plastic deformation. The more plastic deformation the metal undergoes, the harder it becomes, due to work-hardening. The more the metal gets elongated the more its diameter (and hence, cross-sectional area) is decreased. This continues until the point S is reached. After S, the rate at which the reduction in area takes place, exceeds the rate at which the stress increases. Strain becomes so high that the reduction in area begins to produce a localized effect at some point. This is called necking. Reduction in cross-sectional area takes place very rapidly; so rapidly that the load value actually drops. This is indicated by ST. failure occurs at this point T. Then percentage elongation A and reduction in reduction in area W indicate the ductility or plasticity of the material: A=(L-L0)/L0*100% W=(A0-A)/A0*100% Where L0 and L are the original and the final length of the specimen; A0 and A are the original and the final cross-section area. Selected from “testing of metallic materials”Quality assurance and control Product quality is of paramount importance in manufacturing. If quality is allowed deteriorate, then a manufacturer will soon find sales dropping off followed by a possible business failure. Customers expect quality in the products they buy, and if a manufacturer expects to establish and maintain a name in the business, quality control and assurance functions must be established and maintained before, throughout, and after the production process. Generally speaking, quality assurance encompasses all activities aimed at maintaining quality, including quality control. Quality assurance can be divided into three major areas. These include the following:Source and receiving inspection before manufacturing;In-process quality control during manufacturing;Quality assurance after manufacturing. Quality control after manufacture includes warranties and product service extended to the users of the product.Source and receiving inspection before manufacturing Quality assurance often begins ling before any actual manufacturing takes place. This may be done through source inspections conducted at the plants that supply materials, discrete parts, or subassemblies to manufacturer. The manufacturers source inspector travels to the supplier factory and inspects raw material or premanufactured parts and assemblies. Source inspections present an opportunity for the manufacturer to sort out and reject raw materials or parts before they are shipped to the manufacturers production facility. The responsibility of the source inspector is to check materials and parts against design specifications and to reject the item if specifications are not met. Source inspections may include many of the same inspections that will be used during production. Included in these are:Visual inspection;Metallurgical testing;Dimensional inspection;Destructive and nondestructive inspection;Performance inspection.Visual inspections Visual inspections examine a product or material for such specifications as color, texture, surface finish, or overall appearance of an assembly to determine if there are any obvious deletions of major parts or hardware.Metallurgical testing Metallurgical testing is often an important part of source inspection, especially if the primary raw material for manufacturing is stock metal such as bar stock or structural materials. Metals testing can involve all the major types of inspections including visual, chemical, spectrographic, and mechanical, which include hardness, tensile, shear, compression, and spectr5ographic analysis for alloy content. Metallurgical testing can be either destructive or nondestructive.Dimensional inspection Few areas of quality control are as important in manufactured products as dimensional requirements. Dimensions are as important in source inspection as they are in the manufacturing process. This is especially critical if the source supplies parts for an assembly. Dimensions are inspected at the source factory using standard measuring tools plus special fit, form, and function gages that may required. Meeting dimensional specifications is critical to interchangeability of manufactured parts and to the successful assembly of many parts into complex assemblies such as autos, ships, aircraft, and other multipart products.Destructive and nondestructive inspection In some cases it may be necessary for the source inspections to call for destructive or nondestructive tests on raw materials or p0arts and assemblies. This is particularly true when large amounts of stock raw materials are involved. For example it may be necessary to inspect castings for flaws by radiographic, magnetic particle, or dye penetrant techniques before they are shipped to the manufacturer for final machining. Specifications calling for burn-in time for electronics or endurance run tests for mechanical components are further examples of nondestructive tests. It is sometimes necessary to test material and parts to destruction, but because of the costs and time involved destructive testing is avoided whenever possible. Examples include pressure tests to determine if safety factors are adequate in the design. Destructive tests are probably more frequent in the testing of prototype designs than in routine inspection of raw material or parts. Once design specifications are known to be met in regard to the strength of materials, it is often not necessary to test further parts to destruction unless they are genuinely suspect.Performance inspection Performance inspections involve checking the function of assemblies, especially those of complex mechanical systems, prior to installation in other products. Examples include electronic equipment subcomponents, aircraft and auto engines, pumps, valves, and other mechanical systems requiring performance evaluation prior to their shipment and final installation. Selected form “modern materials and manufacturing process”Electro-hydraulic drum brakesApplication The YWW series electro-hydraulic brake is a normally closed brake, suitable for horizontal mounting. It is mainly used in portal cranes, bucket stacker/reclaimersslewing mechanism.The YKW series electro-hydraulic brake is a normally opened brake, suitable for horizontal mounting, employing a thruster as actuator. with the foot controlling switch the operator can release or close the brake. It is mainly used for deceleration braking of portal cranesslewing mechanism. In a non-operating state the machinery can be braked by a manual close device.The RKW series brake is a normally opened brake, which is operated by foot driven hydraulic pump, suitable for horizontal mounting. Mainly used in the slewing mechanism of middle and small portal cranes. When needed, the brake is activated by a manual closed device. Main design featuresInterlocking shoes balancing devices (patented technology) constantly equalizes the clearance of brake shoes on both sides and made adjustment unnecessary, thus avoiding one side of the brake lining sticking to the brake wheel. The brake is equipped with a shoed autoaligning device.Main hinge points are equipped with self-lubricating bearing, making high efficiency of transmission, long service life. Lubricating is unnecessary during operation.Adjustable bracket ensure the brake works well.The brake spring is arranged inside a square tube and a surveyors rod is placed on one side. It is easy to read braking torque value and avoid measuring and computing.Brake lining is of card whole-piece shaping structure, easy to replace. Brake linings of various materials such as half-metal (non-asbestos) hard and half-hard, soft (including asbestos) substance are available for customers to choose.All adopt the companys new types of thruster as corollary equipment which work accurately and have long life. Hydraulic Power TransmissionThe Two Types Of Power Transmission In hydraulic power transmission the apparatus (pump) used for conversion of the mechanical (or electrical,thermal) energy to hydraulic energy is arranged on the input of the kinematic chain ,and the apparatus (motor) used for conversion of the hydraulic energy to mechanical energy is arranged on the output (fig.2-1) The theoretical design of the energy converters depends on the component of the bernouilli equation to be used for hydraulic power transmission. In systerms where, mainly, hydrostatic pressure is utilized, displacement (hydrostatic) pumps and motors are used, while in those where the hydrodynamic pressure is utilized is utilized gor power transmission hydrodynamic energy converters (e.g. centrifugal pumps) are used. The specific characteristic of the energy converters is the weight required for transmission of unit power. It can be demonstrated that the use of hydrostatic energy converters for the low and medium powers, and of hydrodynamic energy converters of high power are more favorite (fig.2-2). This is the main reason why hydrostatic energy converters are used in industrial apparatus. transformation of the energy in hydraulic transmission. 1. driving motor (electric, diesel engine);2. mechanical energy;3. pump; 4. hydraulic energy; 5. hydraulic motor; 6. mechanical energy; 7. load variation of the mass per unit power in hydrostatic and hydrodynamic energy converters 1、hydrostatic; 2.hydrodynamicOnly displacement energy converters are dealt with in the following. The elements performing converters provide one or several size. Expansion of the working chambers in a pump is produced by the external energy admitted, and in the motor by the hydraulic energy. Inflow of the fluid occurs during expansion of the working chamber, while the outflow (displacement) is realized during contraction. Such devices are