0.75型卷揚機設計【絞車】【載荷7.5KN; 速度30m min; 卷筒容繩量100m; 卷筒尺寸φ180mm】【說明書+CAD】,絞車,載荷7.5KN 速度30m min 卷筒容繩量100m 卷筒尺寸φ180mm,說明書+CAD,0.75型卷揚機設計【絞車】【載荷7.5KN,速度30m,min,卷筒容繩量100m,卷筒尺寸φ180mm】【說明書+CAD】,卷揚機 任務書 工 學院 系 專業(yè) 級 班 學 號 學生 指導教師 設計題目 0.75型卷揚機設計 設計工作內容與基本要求（目標、任務、途徑、方法，應掌握的原始資料（數(shù)據(jù)）、參考資料（文獻）以及設計技術要求、注意事項等） 一、設計技術要求、原始資料（數(shù)據(jù)）、參考資料（文獻） 通過實習調研搜集資料，運用所學知識，借助CAXA或AutoCAD軟件，進行總體結構設計及各主要零部件結構如：電機、減速器與制動器選擇、鋼絲繩選擇、卷筒結構的設計與計算等。 主要參數(shù)：額定載荷7.5 KN; 額定速度30 m/min; 卷筒容繩量100 m; 卷筒尺寸?180mm。通過該畢業(yè)設計，使學生對大學四年里學到和未學到的知識進行綜合強化訓練，為其走向工作崗位奠定良好基礎。 二、設計目標與任務 1.查閱文獻資料12種以上，外文資料不少于兩種。寫出3000字以上文獻綜述，單獨裝訂成冊。 2.翻譯外文科技資料，不少于3000漢字，單獨裝訂成冊。 3. 完成總體方案設計。 4.選擇并論證設計傳動方案、整機結構草圖，完成主要零部件的強度校核計算。 5.繪制裝配圖、主要零部件圖，折合零號圖紙兩張以上。 6.編寫摘要，英中文完全對照，中文不少于300字。 7.編寫設計說明書，不少于8000字符。 三、時間安排 1---9周 完成文獻綜述及英文資料翻譯。完成實習?？傮w結構設計、計算 用CAXA或AutoCAD等軟件繪制總裝圖、部裝圖、典型零件圖。 10--12周 編寫設計說明書，進一步修改完善畢業(yè)設計，準備并完成答辯稿答辯。 設計時間： 2012 年 02 月 13 日至 2012 年 05 月 15 日 計 劃 時 間： 2012 年 05 月 19 日 專業(yè)（教研室）審批意見： 審批人簽名： 開題報告表 課題名稱 0.75型卷揚機設計 課題來源 課題類型 指導教師 學生姓名 專 業(yè) 學 號 一、調研資料的準備 根據(jù)任務書的要求，在做本課題前，查閱了與課題相關的資料有：機電一體化技術與系統(tǒng)，液壓與氣壓傳動，CAD軟件制圖，機械設計手冊等相關教材。 二、設計的目的與要求 設計是大學教學中最后一個實踐性教學環(huán)節(jié)，通過該設計過程，可以檢驗我們在大學期間所學的知識，同時培養(yǎng)我們處理工程中實際問題的能力，因此意義特別重大。 通過對題目的理解，查閱各種資料，設計出專用的0.75型卷揚機，以滿足實際的工作需求！ 三、設計的思路與預期成果 1、設計思路 1) 首先：根據(jù)本次設計相關要求查找資料，做好準備。 2) 其次：依據(jù)要實現(xiàn)的功能要求計算并選擇或設計合適的電機，畫出裝配圖。 3) 最后：根據(jù)裝配圖畫出零件圖! 2、預期的成果 （1）完成文獻綜述一篇，不少于3000字，與專業(yè)相關的英文翻譯一篇，不少于3000字。 （2）完成內容與字數(shù)都不少于規(guī)定量的設計說明書一份。 （3）繪制裝配圖，部分零件圖。 四、任務完成的階段內容及時間安排 1周—— 4周 收集設計資料并完成開題報告，完成英文資料翻譯并寫出文獻綜述 5周—— 10周 進行總體設計和部分零部件的選擇與設計 7周——11周 繪制裝配圖和部分零件圖、編寫設計說明書，修改整理，準備答辯 五、完成設計所具備的條件因素 具備機械設計、氣壓與液壓傳動、能有效借助圖書館的相關文獻資料，相關的網(wǎng)絡等資源，查閱機械設計手冊、組合機床設計手冊設計指導手冊并且具有良好的計算機繪圖（CAD）操作能力。 指導教師簽名： 日期： 2012-2-22 課題來源：（1）教師擬訂；（2）學生建議；（3）企業(yè)和社會征集；（4）科研單位提供 課題類型：（1）A—工程設計（藝術設計）；B—技術開發(fā)；C—軟件工程；D—理論研究；E—調研報告 （2）X—真實課題；Y—模擬課題；Z—虛擬課題 要求（1）、（2）均要填，如AY、BX等。 第 6 頁 卷揚機的應用及發(fā)展 摘要：本文簡要介紹了卷揚機的應用領域，卷揚機結構組成及特點，卷揚機的作用以及使用時的注意事項。國內外卷揚機的發(fā)展狀況。通過這些對卷揚機有一個大致的了解，為設計做準備。 關鍵詞：卷揚機，應用，國內外，發(fā)展 前言 卷揚機又叫絞車，是由人力或機械動力驅動卷筒、卷繞繩索來完成牽引工作的裝置?？梢源怪碧嵘?、水平或傾斜拽引重物。卷揚機分為手動卷揚機和電動卷揚機兩種?，F(xiàn)在以電動卷揚機為主。電動卷揚機由電動機、聯(lián)軸節(jié)、制動器、減速器和卷筒組成，共同安裝在機架上。對于起升高度和裝卸量大工作頻繁的情況，調速性能好，能令空鉤快速下降。在很久以前的古代，就知道來用轆轤等來提升重物，以減輕體力勞動的強度和提高勞動生產(chǎn)率。 1. 國內卷揚機的應用與發(fā)展 在我國，解放前卷揚機只有在一些大型企業(yè)中才被使用，應用很少，而且所使用的卷揚機也均為國外生產(chǎn)，國內基本上沒有生產(chǎn)卷揚機的廠家。我國卷揚機的生產(chǎn)是解放后才開始的。 50年代為滿足恢復經(jīng)濟的需要和第一個五年計劃的得要，卷揚機的生產(chǎn)被提到了日程上。原沈陽國泰機器廠(阜新礦山機械廠前身)等成批仿制了兩種卷揚機，一種為日本的JIS8001型動力卷揚機，它是一種原動機為電動機動型式是開式圓柱齒輪傳動，雙錐體摩擦離合器，操作為手扳腳踩的快速卷揚機，另一種是按蘇聯(lián)圖紙制造的1011型和1012型普通蝸桿傳動、電控慢速卷揚機。由于當時生產(chǎn)力不高，卷揚機的需求量亦不多，故這段時間國內卷揚機的生產(chǎn)主要是仿制。 隨著生產(chǎn)力的發(fā)展， 到了60年代，卷揚機的生產(chǎn)和使用越來越多。為了協(xié)調生產(chǎn)，卷揚機主要生產(chǎn)廠家(阜新礦山機械廠、天津卷揚機廠、山西機器廣、寶雞起重運輸機廠等)組成了卷揚機行業(yè)組織，隸屬于第一機械工業(yè)部礦山機械行業(yè)。為了發(fā)展卷揚機的生產(chǎn)，行業(yè)組織了有關廠家的人員對全國卷揚機的生產(chǎn)相應用情況進行了調查。在調查的基礎上，開始自行設計和制造新的卷揚機，先后試制了0.5t、lt、3t電動卷揚機，但由于對當時各廠家的生產(chǎn)能力估計不足，無法推廣。 從70年代起，我國卷揚機的生產(chǎn)進入了技術提高、品種增多的新階段。在各廠自行設計和生產(chǎn)的基礎上，1973年，由卷揚機行業(yè)組織了有關廠家和院校聯(lián)合進行了卷揚機基型設計，并充分考慮到了當時中小廠家的生產(chǎn)能力?？焖倬頁P機的基型采用半開半閉式齒輪傳動，離合器采用單錐面石棉橡膠摩擦帶結構，操縱用手板剎車帶制動。慢速卷揚機的基型式為閉式傳動(圓柱齒輪傳動或蝸桿傳動減速器)、電磁鐵制動結構。這兩種基型一直到現(xiàn)今還在生產(chǎn)。為適應生產(chǎn)發(fā)展的需要，當時第一機械工業(yè)部發(fā)布了JB926—74《卷揚機型式與基本參數(shù)》和JBl803—76《卷揚機技術條件》兩個部標準，并把卷揚機行業(yè)劃歸常德機械研究所(長沙機械研究院前身)領導。隨著部標準的頒布，使卷揚機有了大發(fā)展的基礎。在此期間，由于石化工業(yè)的發(fā)展，大型設備很多，都需要吊裝，如一些大型反應塔，塔的高度達七八十米，質量達五六百噸，就需要有大型吊裝用的卷揚機，因而各廠家相繼生產(chǎn)了20t和32t卷揚機，滿足了經(jīng)濟發(fā)展的需要。 80年代以后，各種競爭機制的引入，科技是第一生產(chǎn)力的概念逐漸被人們所認識，所接受。是我國卷揚機設計制造技術發(fā)展最快的時期。國家也制定了有關卷揚機的配套標準、規(guī)范。新產(chǎn)品種數(shù)近十個，其中最具有代表性的產(chǎn)品有福建省建筑機械廠的行星傳動卷揚機、昆明建筑機械廠的少齒差傳動卷揚機、長沙建筑機械研究所與福州市建筑機械廠聯(lián)合開發(fā)的仿日本Seibu公司采用立式齒輪傳動的電控卷揚機．廣州市一建公司機械廠的高速卷揚機適應高層建筑的多功能需要，而江蘇海門第三機械廠引進專利技術開發(fā)的系列多排頂桿蠕動傳動的卷揚機分為三大系列：即電控、手控和微機程控三大類，其練臺性能優(yōu)于代表國際先進承平的Seibu一字型卷揚機，使我國的建筑卷揚機技術跨人世界先進行列。1991年10月通過的省科委組織的專家鑒定意見：該產(chǎn)品整機組合合理、結構緊湊、重量輕、過載能力強、工作安全可靠，與同類產(chǎn)品相比，居國內先進水平，其中傳動方式部分的設計構思獨特、新穎，受力均勻、合理，屬國內外首創(chuàng)。進入新世紀以來，各行各業(yè)都有飛速發(fā)展，近些年數(shù)控機床的廣泛應用，信息技術和數(shù)控技術日趨成熟，使得機械制造的效率提高、成本降低，這些都將推動卷揚機工業(yè)的發(fā)展。 2. 國外卷揚機的應用與發(fā)展 在國外，卷揚機的品種繁多，應用也很廣泛，在西方技術先進的國家，雖然工業(yè)水平先進，機械化程度不斷提高，起重設備也不斷更新，但仍不能淘汰掉這樣的行之有效的簡單機械設備，下面介紹一下幾個主要國家生產(chǎn)卷揚機的狀況。 （一） 美國 美國生產(chǎn)卷揚機的廠家有近百家，主要有貝波（BEEBE）國際有限公司，哲思（THERN）有限公司等。 貝波國際有限公司是美國較大的生產(chǎn)起重設備的公司，主要產(chǎn)品有各種手動卷揚機，電動卷揚機，提升機械及起重機。手動卷揚機重要品種有蝸桿傳動系列，直齒圓柱齒輪系列，齒輪蝸桿傳動組合系列，直接驅動系列，鏈傳動系列。其中直間驅動式電動卷揚機的傳動是全封閉行星齒輪傳動，傳動系列全部全部安裝在卷筒里面，機架和卷筒用高強度鋼焊接而成 。 （二） 日本 日本從明治30年開始制造和使用卷揚機。據(jù)日本荷役機械研究所設計，1970~1975年間卷揚機的產(chǎn)量增加62.5%。據(jù)日本通產(chǎn)省機械核計月報載,接年單純土卷揚機的產(chǎn)量就達12萬臺,生產(chǎn)值約100億日元。 日本卷揚機行業(yè)由機械技術部會,荷役機械技術委員會領導.主要生產(chǎn)廠家有北川鐵工所,遠藤鋼機,南星,越野總業(yè),松崗產(chǎn)業(yè)等80多個產(chǎn)業(yè)。 （三） 法國 法國生產(chǎn)卷揚機的廠家很多，其中包藤（POTAIN）公司就是生產(chǎn)卷揚機的主要商家之一。包藤公司主要生產(chǎn)KUSW系列卷揚機，LMD系列卷揚機，PC系列卷揚機和RCS系列卷揚機。 （四）國外卷揚機的發(fā)展史 1、大型化 由于基礎工業(yè)的發(fā)展，大型設備和建筑構件要求整體安裝，促進了大型卷揚機的發(fā)展。目前，俄羅斯已生產(chǎn)了60t的卷揚機，日本生產(chǎn)了32t,50t,60t液壓和氣動卷揚機，美國生產(chǎn)了136t和270t卷揚機。 2、采用先進電子技術為了實現(xiàn)自動控制和遙控，國外采用了先進的電子技術。對大型卷揚機安裝了電器連鎖裝置，以保證絕對的安全可靠。 3、發(fā)展手提式卷揚機 為了提高機械化水平，減輕工人勞動強度，國外發(fā)展小型手提式卷揚機，如以汽車蓄電池為動力的直流電動小型卷揚機。 4、大力發(fā)展不帶電源裝置的卷揚機 歐美國家非常重視發(fā)展借助汽車和拖拉機動力的卷揚機。此種卷揚機結構簡單，有一個卷筒和一個變速箱即可。 提升重物是卷揚機的一種主要功能，所以各類卷揚機的設計都是根據(jù)這一要求為依據(jù)的。雖然目前塔吊、汽車吊等取代了卷揚機的部分工作，但由于塔吊成本高，一股在大型工程中使用，而且靈活性較差，故一般中小型工程仍然廣泛應用卷揚機，汽車吊雖然靈活方便，但也因為成本太高，而不能在工程中廣泛應用，故大多設備的安裝仍然是由卷揚機承擔的。卷揚機除在工程、設備安裝等方面被廣泛應用外，在冶金、礦山、建筑、化工、水電、農(nóng)業(yè)、軍事及交通運輸?shù)刃袠I(yè)亦被廣泛應用，還可作現(xiàn)代化電控自動作業(yè)線的配套設備。電機經(jīng)減速機帶動鋼絲繩滾筒，收放鋼絲繩，通過不同的滑輪改變方向。工藝要求主要是滾筒轉速即鋼絲繩運動速度和制動系統(tǒng)的安全可靠性。卷揚機屬于較簡單的提升或牽引機械。主要是用電動機作為原動機，由于電動機輸出的轉速遠遠大于卷揚機中滾筒的轉速，故必須設計減速的傳動裝置。傳動裝置的設計有多種多樣，如皮帶減速器、鏈條減速器、齒輪減速器、渦輪蝸桿減速器、二級齒輪減速器等等。通過合理的設計傳動裝置，使得卷揚機能夠在特定的工作環(huán)境下滿足正常的工作要求。 機械設計是為實現(xiàn)高等院校機械類專業(yè)培養(yǎng)高級應用型、技術型人才培養(yǎng)目標所必須的實踐性教學環(huán)節(jié)。通過設計強化學生對基本知識和基本技能的理解和掌握,培養(yǎng)學生收集資料和調查研究的能力,一定的方案比較、論證的能力,一定的理論分析與設計運算能力,以及編寫編制能力。同時掌握資料的收集和分析、相關規(guī)范的選擇和運用；設計方案的選擇、成果圖的繪制以及設計文本的編制全過程。另外對培養(yǎng)學生獨立思考問題和解決問題的能力,為今后工作做好技術儲備,都具有十分重要意義。通過設計，學生可以鞏固和提高學過的基礎理論和專業(yè)知識；提高運用所學專業(yè)知識進行獨立思考和綜合分析、解決實際問題的能力；培養(yǎng)掌握正確的思維方法和利用計算機解決實際問題的基本技能；增強對信息管理工作的認識，掌握信息處理方法，進行編制技術文件等基本技能的訓練，使之具有一定程度的實際工作能力；掌握文獻檢索、資料查詢的基本方法以及獲取新知識的能力；促使學習和獲取新知識，掌握自我學習的能力。通過參與實際工作，學生可以更了解工作，具備一定的實際工作能力。就本次設計而言，本人可以熟悉卷揚機的工作原理，其各部分機構及零件的設計計算，對所學過的機械制圖、工程力學、工程材料、機械設計基礎和公差知識進行一次綜合運用。這對以后的機械專業(yè)工作會有很大幫助。 參考文獻 [1]齊國志 建筑卷揚機的設計 機械工業(yè)出版社 1996 [2]龔桂義 機械設計課程設計指導書 高等教育出版社 1982 [3]龔桂義 機械設計課程設計圖冊 哈爾濱工業(yè)大學出版社 1945 [4]機械設計手冊 機械工業(yè)出版社 2003 [5]劉鴻文 材料力學 高等教育出版社 1992 [6]周明衡 離合器制動器選用手冊 化工工業(yè)出版社 2003 [7]汪愷 機械設計標準應用手冊 機械工業(yè)出版社 1997 [8]成大先 機械設計手冊 化工工業(yè)出版社 1993 [9]胡家秀 簡明機械零件設計選用手冊 機械工業(yè)出版社 1999 [10]齒輪手冊編委會 齒輪手冊（第二版）北京：機械工業(yè)出版社，2004 [11]羅伯特 機械設計中的機械零件（第三版）北京：機械工業(yè)出版社，2004 [12]徐灝 疲勞強度設計 北京：機械工業(yè)出版社 1985 [13]陳裕成 建筑機械與設備 北京：北京理工大學出版社 2009 [14]孔慶華 母福生劉傳紹 極限配合與測量技術基礎 上海：同濟大學出版社2008 [15]張順心 工程圖學基礎 北京：機械工業(yè)出版社2007 [16]Manually operated windlass mechanism for portable elevators application filed apr.19.1913 [17]Automatic braking arrangement for a windlass Jan van Gennep,715 Laurel Ave, Menlo Park, Calif.94025 Mar.20,1975 設計 文獻綜述 院（系）名稱 專業(yè)名稱 學生姓名 指導教師 2012年 03 月 10 日 第 27 頁 原文說明 原文說明的內容是：文章闡述了電機的工作原理、發(fā)展過程、以及伺服電機的工作控制原理。并且舉例說明了伺服電機所適用的場合。 題名:Servomotor’s Elements and Applications 作者: NEWMARKER How Does a Motor Work? An electric motor converts electricity into mechanical motion. Electric motors are used in household appliances, electric fans, remote-controlled toys, and in thousands of other applications. The electric motor grew out of one of the earliest discoveries in electric science—Arago’s rotations. In 1824, Francois Arago discovered that a magnetic needle suspended over a copper disk would rotate when the disc was spun. The next year, computer pioneer Charles Babbage and astronomer John Herschel showed that the action could be reversed: spinning a more powerful magnet above the copper disk would spin the copper disc. Then, in 1831, Michael Faraday conducted experiments that helped explain why this took place. While this laid the groundwork for the electric motor, it was another half century before electric motors were doing useful work. Over the next few decades many inventors made improved devices for turning electricity into motion. One of these was Hippolyte Pixii’s 1832 improvement called the commutator, which switched the flow of current between two or more sets of stationary electromagnets to keep a motor continuously rotating. Thomas Davenport was the first to build an electric motor large enough to be used in industry, and he was also the first to seek a patent on a motor. Soon electric motors were being used for such things as transportation. Moritz-Hermann De Jacobi used an electric motor on a boat on the Neva River, and Charles G. Page used one to build a small locomotive. After the appearance of commercial electric power systems in the 1880s, larger electric motors were possible. Edison encouraged the use of electric motors in industrial applications and designed several new electric motors for that purpose. An important change came in the later 1880s and 1890s, when electric power companies began considering the switch to alternating current. Alternating current was perfect for the distribution of electric power over long distances, and it worked well with the Edison electric lamp, but no practical AC motor existed until the works of Galileo Ferraris in Italy and Nikola Tesla in the United States. Tesla’s contributions are remembered today more than Ferraris’ in part because Tesla was subsequently hired by the Westinghouse corporation, which used his patents along with many others to become one of the major producers of electric equipment. With a suitable AC motor available, AC power took off. It is still in use today. Servomotor Servomotors are available as AC or DC motors. Early servomotors were generally DC motors because the only type of control for large currents was through SCRs for many years. As transistors became capable of controlling larger currents and switching the large currents at higher frequencies, the AC servomotor became used more often. Early servomotors were specifically designed for servo amplifiers. Today a class of motors is designed for applications that may use a servo amplifier or a variable-frequency controller, which means that a motor may be used in a servo system in one application, and used in a variable-frequency drive in another application. Some companies also call any closed-loop system that does not use a stepper motor a servo system, so it is possible for a simple AC induction motor that is connected to a velocity controller to be called a servomotor. Some changes that must be made to any motor that is designed as a servomotor includes the ability to operate at a range of speeds without overheating, the ability to operate at zero speed and retain sufficient torque to hold a load in position, and the ability to operate at very low speeds for long periods of time without overheating. Older-type motors have cooling fans that are connected directly to the motor shaft. When the motor runs at slow speed, the fan does not move enough air to cool the motor. Newer motors have a separate fan mounted so it will provide optimum cooling air. This fan is powered by a constant voltage source so that it will turn at maximum RPM at all times regardless of the speed of the servomotor. One of the most usable types of motors in servo systems is the permanent magnet (PM) type motor. The voltage for the field winding of the permanent magnet type motor can be AC voltage or DC voltage. The permanent magnet-type motor is similar to other PM type motors presented previously. Figure-1 shows a cutaway picture of a PM motor and Fig.-2 shows a cutaway diagram of a PM motor. From the picture and diagram you can see the housing, rotor and stator all look very similar to the previous type PM motors. The major difference with this type of motor is that it may have gear reduction to be able to move larger loads quickly from a stand still position. This type of PM motor also has an encoder or resolver built into the motor housing. This ensures that the device will accurately indicate the position or velocity of the motor shaft. FIGURE 1-1 Typical PM servomotors FIGURE 1-2 Cutaway picture of a permanent magnet servomotor Brushless Servomotors The brushless servomotor is designed to operate without brushes. This means that the commutation that the brushes provided must now be provided electronically. Electronic commutation is provided by switching transistors on and off at appropriate times. Figure 1-3 shows three examples of the voltage and current waveforms that are sent to the brushless servomotor. Figure 1-4 shows an example of the three windings of the brushless servomotor. The main point about the brushless servomotor is that it can be powered by either ac voltage or dc voltage. FIGURE 1-3 (a) Trapezoidal input voltage and square wave current waveforms. (b) Sinusoidal input voltage and sinusoidal voltage and square wave output voltage waveforms. (c) Sinusoidal input voltage and sinusoidal current waveforms. This has become the most popular type of brushless servomotor control. Figure 1-4 shows three sets of transistors that are similar to the transistors in the output stage of the variable-frequency drive. In Fig. l-4a the transistors are connected to the three windings of the motor in a similar manner as in the variable-frequency drive. In Fig. l-4b the diagram of the waveforms for the output of the transistors is shown as three separate sinusoidal waves. The waveforms for the control circuit for the base of each transistor are shown in Fig. l-4c. Figure l-4d shows the back EMF for the drive waveforms. FIGURE 11-86 (a) Transistors connected to the three windings of the brushless servomotor. (b) Waveforms of the three separate voltages that are used to power the three motor windings. (c) Waveforms of the signals used to control the transistor sequence that provides the waveforms for the previous diagram, (d) Waveform of the overall back EMF Servomotor Controllers Servomotor controllers have become more than just amplifiers for a servomotor. Today servomotor controllers must be able to make a number of decisions and provide a means to receive signals from external sensors and controls in the system, and send signals to host controllers and PLCs that may interface with the servo system. Figure 1-5 shows a picture of several servomotors and their amplifiers. The components in this picture look similar to a variety of other types of motors and controllers. FIGURE 1-5 Example servomotors and amplifiers Figure 1-6 shows a diagram of the servomotor controller so that you can see some of the differences from other types of motor controllers. The controller in this diagram is for a DC servomotor. The controller has three ports that bring signals in or send signals out of the controller. The power supply, servomotor, and tachometer are connected to port P3 at the bottom of the controller. You can see that the supply voltage is 115-volt AC single phase. A main disconnect is connected in series with the LI wire. The LI and N lines supply power to an isolation step-down transformer. The secondary voltage of the trans-former can be any voltage between 20 and 85 volts. The controller is grounded at terminal 8. You should remember that the ground at this point is only used to provide protection against short circuits for all metal parts in the system. The servomotor is connected to the controller at terminals 4 and 5. Terminal 5 is + and terminal 4 is - . Terminal 3 provides a ground for the shield of the wires that connect the motor and the controller. The tachometer is connected to terminals 1 and 2. Terminal 2 is + and terminal 1 is - . The shield for this cable is grounded to the motor case. The wires connected to this port will be larger than wires connected to the other ports, since they must be capable of carrying the larger motor current. If the motor uses an external cooling fan, it will be connected through this port. In most cases the cooling fan will be powered by single-phase or three-phase AC voltage that remains at a constant level, such as 110 volts AC or 240 volts AC. FIGURE 1-6 Diagram of a servo controller. This diagram shows the digital (on-off) signals and the analog signals that are sent to the controller, and the signals the controller sends back to the host controller or PLC. The command signal is sent to the controller through port PI. The terminals for the command signal are 1 and 2. Terminal 1 is + and terminal 2 is - . This signal is a type signal, which means that it is not grounded or does not share a ground potential with any other part of the circuit. Several additional auxiliary signals are also connected through port 1. These signals include inhibit (INH), which is used to disable the drive from an external controller, and forward and reverse commands (FAC and RAC), which tell the controller to send the voltage to the motor so that it will rotate in the forward or reverse direction. In some applications, the forward maximum travel limit switch and reverse maximum travel limit switch are connected so that if the machine travel moves to the extreme position so that it touches the overtravel limit switch, it will automatically energize the drive to begin travel in the opposite direction. Port PI also provides several digital output signals that can be used to send fault signals or other information such as "drive running" back to a host controller or PLC. Port PI basically is the interface for all digital (on-off) signals. Port P2 is the interface for analog (0-max) signals. Typical signals on this bus include motor current and motor velocity signals that are sent from the servo controller back to the host or PLC where they can be used in verification logic to ensure the controller is sending the correct information to the motor. Input signals from the host or PLC can also be sent to the controller to set maximum current and velocity for the drive. In newer digital drives, these values are controlled by drive parameters that are programmed into the drive. PWM Servo Amplifier The PWM servo amplifier is used on small-size servo applications that use DC brush-type servomotors. Figure 1-7 shows a diagram for this type of amplifier. From the diagram you can see that single-phase AC power is provided to the amplifier as the supply at the lower left part of the diagram. The AC voltage is rectified and sent to the output section of the drive that is shown in the top right comer of the diagram. The output section of the drive uses four IGBTs to create the pulse-width modulation waveform. The IGBTs are connected so that they provide 30-120 volts DC and up to 30 A to the brush-type DC servo-motor. The polarity of the motor is indicated in the diagram. The remaining circuits show a variety of fault circuits in the middle of the diagram that originate from the fault logic board and provide an output signal at the bottom of the diagram. You should notice that the fault output signals include overvoltage, overtemperature, and overcurrent. A fourth signal is identified as SSO (system status output), which indicates the status of the system as faulted anytime a fault has occurred. A jumper is used to set the SSO signal as an open collector output with a logic level "1" indicating the drive is ready, or as a normally closed relay indicating the drive is ready. The input terminals at the bottom right part of the diagram are used to enable or inhibit the drive, and to select forward amplifier clamp (FAC) or reverse amplifier clamp (RAC). The inhibit signal is used as a control signal, since it inhibits the output stage of the amplifier if it is high. The FAC and RAC signals limit the current in the opposite direction to 5%. The input signals are shown in the diagram at the upper left side. The VCS (velocity command signal) requires a +VCS and a -VCS signal to provide the differential signal. FIGURE 1-7 Diagram of a pulse-width modulator (PWM) amplifier with a brush-type DC servomotor Applications for Servo Amplifiers and Motors You will get a better idea of how servomotors and amplifiers operate if you see some typical applications. Figure 1-8 shows an example of a servomotor used to control a press feed. In this application sheet material is fed into a press where it is cut off to length with a knife blade or sheer. The sheet material may have a logo or other advertisement that must line up registration marks with the cut-off point. In this application the speed and position of the sheet material must be synchronized with the correct cut-off point. The feed-back sensor could be an encoder or resolver that is coupled with a photoelectric sensor to determine the location of the registration mark. An operator panel is provided so that the operator can jog the system for maintenance to the blades, or when loading a new roll of material. The operator panel could also be used to call up parameters for the drive that correspond to each type of material that is used. The system could also be integrated with a programmable controller or other type of controller and the operator panel could be used to select the correct cutoff points for each type of material or product that is run. FIGURE 1-8 Application of a servomotor controlling the speed of material as it enters a press for cutting pieces to size. An Example of a Servo Controlled In-Line Bottle-Filling Application A second application is shown in Fig. 1-9. In this application multiple filling heads line up with bottles as they move along a continuous line. Each of the filling heads must match up with a bottle and track the bottle while it is moving. Product is dispensed as the nozzles move with the bottles. In this application 10 nozzles are mounted on a carriage that is driven by a ball-screw mechanism. The ball-screw mechanism is also called a lead screw. When the motor turns the shaft of the ball screw, the carriage will move horizontally along the length of the ball-screw shaft. This movement will be smooth so that each of the nozzles can dispense product into the bottles with little spillage. The servo drive system utilizes a positioning drive controller with software that allows the position and velocity to be tracked as the conveyor line moves the bottles. A master encoder tracks the bottles as they move along the conveyor line. An auger feed system is also used just prior to the point where the bottles enter the filling station. The auger causes a specific amount of space to be set between each bottle as it enters the filling station. The bottles may be packed tightly as they approach the auger, but as they pass through the auger their space is set exactly so that the necks of the bottles will match the spacing of the filling nozzles. A detector is also in conjunction with the dispensing system to ensure that no product is dispensed from a nozzle if a bottle is missing or large spaces appear between bottles. FIGURE 1-9 Application of a beverage-filling station controlled by a servomotor The servo drive system compares the position of the bottles from the master encoder to the feedback signal that indicates the position of the filling carriage that is mounted to the ball screw. The servo drive amplifier will increase or decrease the speed of the ball-screw mechanism so that the nozzles will match the speed of the bottles exactly. An Example of a Servo Controlled Precision Auger Filling System A third application for a servo system is provided in Fig. 1-10. In this application a large filling tank is used to fill containers as they pass along a conveyor line. The material that is dispensed into the containers can be a single material fill or it can be one of several materials added to a container that is dumped into a mixer for a blending operation. Since the amount of material that is dispensed into the container must be accurately weighed and metered into the box, an auger that is controlled by a servo system is used. The feedback sensor for this system can be a weighing system such as the load cell discussed in earlier chapters. The command signal can come from a programmable controller or the operator can enter it manually by selecting a recipe from the operator's terminal. The amount of material can be different from recipe to recipe. FIGURE 1-10 Application of a precision auger filling station controlled by a servomotor. The speed of the auger can be adjusted so that it runs at high speed when the container is first being filled, and the speed can be slowed to a point where the final grams of material can be metered precisely as the container is filled to the proper point. As the price of material increases, precision filling equipment can provide savings as well as quality in the amount of product used in the recipe. An Example of a Label Application Using Servomotors The fourth application has a servomotor controlling the speed of a label-feed mechanism that pulls preprinted labels from a roll and applies them to packages as they move on a continuous conveyor system past the labeling mechanism. The feedback signals are provided by an encoder that indicates the location of the conveyor, tach generator that indicates the speed of the conveyor, and a sensor that indicates the registration mark on each label. The servo positioning system is controlled by a microprocessor that sets the error signal, and the servo amplifier that provides power signals to the servomotor. This application is shown in Fig. 1-11. FIGURE 1-11 Example of a labeling application controlled by a servomotor An Example of a Random Timing Infeed System Controlled by a Servomotor The fifth application is presented in Fig. 1-12, and it shows a series of packaging equipment that operates as three separate machines. The timing cycle of each station of the packaging system is independent from the others. The packaging system consists of an infeed conveyor, a positioning conveyor, and a wrapping station. The infeed conveyor and the wrapping station are mechanically connected so that they run at the same speed. The position of the packages on the wrapping station must be strictly controlled so that the packages do not become too close to each other. A piece of metal called a flight is connected to the wrapping station conveyor at specific points to ensure each package stays in position. A sensor is mounted at the beginning of the positioning conveyor to determine the front edge of the package when it starts to move onto the positioning conveyor. A second sensor is positioned at the bottom of the packaging conveyor to detect the flights. Both of these signals from the sensors are sent to the servomotor to provide information so the servo can adjust the speed of the positioning conveyor so that each package aligns with one of the flights as it moves onto the packaging conveyor