轉塔刀架設計及相關技術研究【含11張cad圖紙+文檔全套資料】
喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請放心下載，，有疑問咨詢QQ:414951605或者1304139763 ======================== 喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請放心下載，，有疑問咨詢QQ:414951605或者1304139763 ========================
畢 業(yè) 設 計 任 務 書
1．畢業(yè)設計的任務和要求：
掌握機床轉塔刀架的基本知識；研究數(shù)控機床轉塔刀架及刀庫的關鍵技術，了解其選型、應用及設計方法等；完成一種數(shù)控機床用轉塔刀塔的設計，要求裝刀數(shù)量不少于8把，刀柄接口、轉位精度、轉位速度等滿足普通精度機床的需要。
2．畢業(yè)設計的具體工作內(nèi)容：
1） 分析題目要求，查閱相關的國內(nèi)外文獻、設計資料、有關專利文獻等，在此基礎上，了解開題報告的撰寫方法、基本要求，完成開題報告；
2） 學習和掌握轉塔刀架的有關知識，了解數(shù)控機床轉塔刀架設計的關鍵技術及發(fā)展現(xiàn)狀；了解數(shù)控機床、加工中心對轉塔刀架的要求；總結轉塔刀架的設計要點、技術關鍵及發(fā)展方向；力爭提出轉塔刀架設計的發(fā)展方向；
3） 按題目要求，設計一種滿足普通精度數(shù)控機床使用的轉塔刀架，完成結構圖、主要零件圖設計，給出回轉精度、轉位速度、刀具接口等必要的計算說明；
4） 編寫設計說明書；
5） 翻譯本專業(yè)外文科技文獻一份。
畢 業(yè) 設 計 任 務 書
3．對畢業(yè)設計成果的要求：
1）轉塔刀架裝配圖、主要零件圖一套；
2）轉塔刀架的研究及設計說明書一份；
3）本專業(yè)外文科技文獻譯文一份。
4．畢業(yè)設計工作進度計劃：
起 迄 日 期
工 作 內(nèi) 容
2016年
02月29日 ~03月21日
03月22日 ~04月30日
05月01日 ~05月20日
05月21日 ~05月31日
06月01日 ~06月05日
分析課題要求，查閱相關文獻資料，了解轉塔刀架設計的國內(nèi)外現(xiàn)狀及發(fā)展趨勢，提出自己的設計思路，完成開題報告；
全面掌握轉塔刀架的基本知識，了解數(shù)控機床對轉塔刀架的要求，了解轉塔刀架的設計特點；分析總結轉塔刀架的發(fā)展方向；
完成轉塔刀架結構圖、主要零件圖的設計；
完成研究總結及設計說明書
撰寫答辯講稿，準備答辯；
學生所在系審查意見：
同意下發(fā)任務書
系主任：
2016年 2 月 29日
畢 業(yè) 設 計 開 題 報 告
1．結合畢業(yè)設計情況，根據(jù)所查閱的文獻資料，撰寫2000字左右的文獻綜述：
文 獻 綜 述
1課題目的及意義
數(shù)控轉塔刀架是加工中心、數(shù)控車床必備的機床附件，是數(shù)控車床上的核心功能部件之一，尤其適用全功能數(shù)控車床。當前，數(shù)控機床發(fā)展迅猛，一方面向高速、高效、高精度方面發(fā)展，同時，在制造行業(yè)中廣泛存在原有設備的數(shù)控改造和系統(tǒng)升級問題。作為關鍵附件，高性能的數(shù)控轉塔刀架對于提高機床整體運行的可靠性、穩(wěn)定性和效率有著重要意義，數(shù)控轉塔刀架是由數(shù)控系統(tǒng)來控制的，因此，在轉塔刀架本身性能提高的情況下，如何實現(xiàn)控制任務就顯得十分重要了[1-3]。因此數(shù)控車床的刀架設計的好與壞、效率高與低將直接影響到產(chǎn)品的加工時間和質量，進而影響到制造業(yè)的飛速發(fā)展。
本設計主要通過大量閱讀文獻掌握機床轉塔刀架的基本知識；研究數(shù)控機床轉塔刀架及刀庫的關鍵技術，了解其選型、應用及設計方法等；完成某種數(shù)控銑床用轉塔刀塔的設計，并且轉塔刀架的裝刀數(shù)量不少于8把，對于數(shù)控車床轉塔刀架設計的基本要求是轉位準確可靠，工作平穩(wěn)安全；轉位時間短；轉位 以后重復定位精度高；防水防屑，密封性能優(yōu)良；夾緊剛性高，適宜重負荷切削。
2.課題研究現(xiàn)狀
2.1國內(nèi)對轉塔刀架的研究現(xiàn)狀
我國數(shù)控機床約有幾十年的歷史,目前正處在高速發(fā)展期,采用的刀架多為液壓凸
輪刀架,關于伺服動力刀架技術的研究剛剛起步[4]。隨著對機床精度、速度、可靠性、復
合化程度等的要求的提高,迫切需要自主研發(fā)目前主要依靠進口的伺服刀架和伺服動力
刀架,以滿足高檔數(shù)控機床發(fā)展的需要。
目前國內(nèi)主要刀架產(chǎn)品生產(chǎn)廠家有:煙臺環(huán)球、常州宏達、常州亞興、臺灣六鑫、
臺灣德士、臺灣亙陽、沈陽精誠等。經(jīng)過近幾年的發(fā)展,國內(nèi)及時跟蹤國外先進技術,
不斷開發(fā)推出新產(chǎn)品,刀架技術得到了很大提高[5]。
煙臺環(huán)球公司研制的AK系列刀架采用伺服電機進行分度,液壓控制松開,以端
齒輪(三聯(lián)齒輪)進行精密定位,可實現(xiàn)雙向轉位就近選刀,,中心高有80mm、100mm和125mm,刀孔的定位精度達士,重復定位精度達士轉位180度的分度時間達到1.0s,最多同時能裝12把刀,動力刀具轉速達5000rpm[6]。
臺灣德士公司研制的中心高不同的軸向動力刀架和徑向動力刀架在精度、換刀時間
方面等都有了提高[7]。相鄰兩刀的換刀時間為0.15s,轉位180度的時間為0.72s,重復定位精度達，動力刀具轉速達4000rpm。
2.2國外對轉塔刀架的研究現(xiàn)狀
數(shù)控機床的發(fā)展己有五十多年的歷史,伺服刀架的發(fā)展約有二十年的歷史,伺服動力刀架有十余年的歷史,己進入成熟期[8-10]。國外刀架發(fā)展的趨勢是:液壓凸輪刀架、電動刀架、伺服刀架、分度馬達刀架、動力刀架、帶Y軸刀架、帶B軸刀架及直聯(lián)式力矩電機刀架等[11]。
目前,日本、德國、英國等發(fā)達國家均有成熟的刀架產(chǎn)品生產(chǎn),如德國Index公司開發(fā)的車削中心V300Vertical Line上固定安裝一個立式刀具臺和1~2個轉塔動力刀架,可配置26把單獨驅動的動力刀具;日本的Hitachi Seiki公司的Tricell有3個刀架,兩個分別對應左、右側對置主軸,第三個起平衡兩主軸加工時間的作用;日本村田機械的MW系列有兩平行并列主軸,卡盤端面面向操作者,每軸配一個刀架,便于排屑和操作,適于盤類零件加工[12]。
國外數(shù)控機床刀架的專業(yè)生產(chǎn)廠家主要有:德國肖特(SAUTER)、意大利巴拉法第(BARUFFALDI)、杜普馬帝克(DUPLOMATIC)等,這些專業(yè)廠家刀架生產(chǎn)歷史悠久,產(chǎn)品系列全[13]。
德國肖特(SAUTER)是國外生產(chǎn)刀架產(chǎn)品質量較好的公司,其研制的刀架多種多樣,主要有電動刀架、雙馬達伺服刀架、單馬達伺服刀架、四方刀架、B軸刀架和皇冠刀架等[14]。電動刀架控制簡單,能夠實現(xiàn)軸向和徑向出刀,具有Y軸功能;雙馬達伺服刀架具有極佳的溫度穩(wěn)定性,也具有軸向和徑向出刀能力,適用于背面加工;單馬達伺服刀架定位和動力刀共享單一馬達,能夠實現(xiàn)超高速定位,180°分度時間達到0.92s同時具有Y軸功能;B軸刀架兼具Y軸及刀庫功能,適用于復雜工件的切削及輪廓銑削,重復定位精度高達;皇冠刀架尺寸小,換刀快,可達0.2s,主軸轉速高達18000rpm,定位準確,其定位精度,重復定位精度,最多可以8個獨立刀座及多頭刀座,刀架內(nèi)部具有超載保護裝置可減少撞車時對刀架的損壞,換刀時刀盤不需有抬起動作,適宜在生產(chǎn)線上大量使用[15]。
2.3 國內(nèi)與國外的差距
我國的數(shù)控機床行業(yè)與世界先進制造行業(yè)相比，存在很大的差距，而重要的原因是功能部件行業(yè)趕不上數(shù)控機床的發(fā)展[16]。特別是數(shù)控轉塔刀架行業(yè)，在2007年制定了國家標準，但是標準要求比較低,雖然每個企業(yè)都有了自主知識產(chǎn)權，但生產(chǎn)的產(chǎn)品以中、低檔次為主。中、高檔次產(chǎn)品都是從中國臺灣地區(qū)和國外引進，特別是歐洲國家，像意大利的迪普馬、巴拉法蒂，德國的肖特等都是有幾十年的數(shù)控轉塔刀架設計、研發(fā)、生產(chǎn)的專業(yè)企業(yè)，有豐富的經(jīng)驗積累，擁有自主知識產(chǎn)權，擁有自己的標準，有先進的加工檢測手段，其精度等級、技術參數(shù)都遠高于我國國家標準和任何一家企業(yè)標準。但是，進口刀架的價格昂貴，交貨周期長，因此，目前配置在國內(nèi)數(shù)控機床上的進口高檔次功能部件還是比較少的[17]。而中國臺灣地區(qū)的液壓刀架其穩(wěn)定性、可靠性、適應性基本達到國際同類產(chǎn)品水平，而且有自己的特點，與歐洲產(chǎn)品相比，價格適中，具有很高的性價比。因此，臺灣的數(shù)控轉塔刀架在大陸有一定的占有量，而且在中檔次機床的配置尤為突出[18]。如何提升自己產(chǎn)品的技術含量，既適合我國數(shù)控機床發(fā)展的實際需要，又能在國際市場競爭中有一席之地，是我們值得思考的問題和今后各個企業(yè)所要走的路。
3. 轉塔中心換刀原理分析
3.1 主軸電機動力傳遞
轉塔中心的主軸切削加工和八角頭轉動換刀所需的動力由同一電機（主軸電機）提供，那么主軸電機的動力到底是如何傳遞給主軸和八角頭分度機構的，則需將各部件結合起來進行深入分析后才可得知。經(jīng)研究分析可得到主軸電機的動力流程，如圖 1 所示。
由于主軸轉動，進行加工切削時，不允許八角頭轉動；八角頭轉動進行換刀時，主軸應失去動力。[19]因此由一個電機為兩者提供動力是不沖突的，并能節(jié)省成本和能源。而主軸的轉動和八角頭的轉動不能同時進行，這是由離合器與滑動離合器的機械互鎖來保證的，兩個離合器依靠機械結構來協(xié)調動作，進行互鎖，在同一時間，只能有一個離合器處于閉合狀態(tài)。
圖1 主軸電機動力傳遞流程
3.2 轉塔中心換刀原理
通過以上分析可知，轉塔中心的自動換刀是通過一系列的機械機構的協(xié)調動作來完成的。主要通過兩個離合器的是否閉合來控制主軸電機的動力傳遞，當滑動離合器閉合時，主軸電機帶動主軸轉動，進行切削工；當離合器閉合時，主軸電機帶動六角頭轉動，進行主軸和刀具的更換，兩個離合器通過機械結構互鎖。利用凸輪與離合器撥叉的配合保證每次換刀，凸輪軸只轉動一圈，離合器便分離；再利用槽輪機構實現(xiàn)分度，保證每次換刀六角頭只轉動 60°。而凸輪軸上的凸輪與離合器臂的配合則使得，每次換刀前分度定位柱塞退出定位，而換刀結束后再對六角頭進行定位，使得主軸和刀具具有較高的重復定位精度。每次換刀，六角頭能自動轉動 60°，更換至下一根主軸用于切削加工，實現(xiàn)機床自動換刀[20]。
參考文獻：
[1]李憲凱.車銑復合加工中心結構分析[J]．設備管理與維修，2006(1)：36．
[2]郭永環(huán).數(shù)控車床用轉塔動力刀架的發(fā)展方向[J]．機床與液壓，2002(6)：24-26．
[3]吉濤，劉乘.多工位轉塔刀架的數(shù)控實現(xiàn)[J]．機床與液壓。2006(9)：89．
[4]蘇曉暉．機床六工位轉塔動力刀架的設計[J]．制造技術與機床，2010(3)：46．
[5] 陳代隆，于天標．多工位液壓數(shù)控轉塔刀架[J]．沈陽工業(yè)大學學報，1999，21(4)：312．
[6]陳日曜．金屬切削原理[M]．北京：機械工業(yè)出版社，2002．
[7]俞文海，李朝榮．八工位回轉刀架的設計研究[J]．制造技術與機床，1998(6)：
[8]盧建偉. 數(shù)控車床轉塔刀架可靠性試驗臺的研制[D].吉林大學,2011.
[9]鄭申,張瑞乾. 多工位數(shù)控轉塔動力刀架設計[J]. 機械研究與應用,2010,05:84-86+88.
[10]董紅召. 車削中心轉塔刀架布刀的GA優(yōu)化方法[J]. 農(nóng)業(yè)機械學報,2007,02:172-175+200.
[11]樓俏. 數(shù)控車床動力轉塔刀架可靠性試驗臺的研制[D].吉林大學,2012.
[12]姜玉龍. 數(shù)控車床轉塔刀架可靠性試驗臺的電液伺服加載系統(tǒng)研制[D].吉林大學,2012.
[13]吉濤,劉乘. 多工位轉塔刀架的數(shù)控實現(xiàn)[J]. 機床與液壓,2006,09:89-90+116.
[14]盧金鼎,劉滿銀. 數(shù)控轉塔刀架的開發(fā)應用[J]. 機械制造,1998,02:32-34.
[15] 李德貴.數(shù)控加工切削用量的選擇[J].中國高新技術企業(yè)，2013，(11)：94~95.
[16] 丁義軍.關于數(shù)控加工中的刀具和切削用量的探討[J].科技致富向導，2011，(33).
[17] 徐溥滋，張舒勃等.專用機床設計與制造[M].黑龍江：黑龍江人民出版社，1979.
[18] 李剛.鉆銑床主傳動設計與校核[J].機床與液壓，2011，39(20)：121~123.
[19] 彭磊.同步帶傳動在全墊升氣墊船上的應用[J].船舶，2012，23(03)：45~49.
[20] 吳彬.多功能鐘表機床的研制[D].上海：上海大學機電工程與自動化學院，2009
畢 業(yè) 設 計 開 題 報 告
2．本課題要研究或解決的問題和擬采用的研究手段（途徑）：
2.1.研究解決的問題 ：
1） 機床的轉塔刀架設計，包括動力方案設計、參數(shù)計算和整體布局設計。
2） 機床關鍵部件——轉塔中心的內(nèi)部機構和換刀原理的研究和分析。
3) 根據(jù)機床的功能要求，設計一種符合要求的轉塔刀架。
4) 學習Autocad,繪制出轉塔刀架的零件圖，裝配圖。
2.2研究方案
1）從人機工程學的角度進行機床的整體布局設計。
2) 對現(xiàn)有自動換刀裝置——轉塔中心進行分析，通過工程分析和研究，設計新型裝置，提高換刀速度和精度
3) 完成一種數(shù)控滿足刀數(shù)和精度的機床轉塔刀架的設計。
4) 利用數(shù)控系統(tǒng)和 機床控制系統(tǒng)，實現(xiàn)機床的各種控制功能，保證機床穩(wěn)定可靠地運行。
2.3.工作進度安排
第1-2周：選擇設計方向，收集資料，確定設計內(nèi)容，撰寫開題報告。
第3-4周：調研。
第5-6周：學習轉塔刀架的設計方法。
第7-8周：繪制轉塔刀架的結構示意圖。
第9-10周：根據(jù)設計要求對相關參數(shù)進行計算。
第11-12周：運用AutoCAD繪制轉塔刀架工程圖。
第13周：完成論文初稿，根據(jù)提出的修改意見完善圖紙及論文。
第14周：畢業(yè)設計定稿、打印，畢業(yè)答辯。
畢 業(yè) 設 計 開 題 報 告
指導教師意見：
報告表明，該同學近期查閱了一些數(shù)控機床，數(shù)控刀具刀架方面的文獻資料，對其發(fā)展歷程有了初步的了解，但深入技術細節(jié)不夠對研究現(xiàn)狀,產(chǎn)品中的新技術了解不多，因此只提出了設計的思路，后期應盡快制定更詳細的方案。
同意開題
指導教師：
2016 年 3 月 22 日
所在系審查意見：
系主任：
2016年 3 月 22 日
轉塔刀架設計及相關技術研究
摘要：數(shù)控轉塔刀架作為衡量一臺車床好壞的核心功能部件之一,其性能的優(yōu)劣,直接影響著車床的加工精度和加工效率。但是,由于現(xiàn)有普遍使用的伺服電機低速扭矩特性不好,所以在使用時必須使用減速齒輪機構來滿足轉塔刀架在低速旋轉時所產(chǎn)生的大扭矩。而直接傳動裝置是由電機不通過中間齒輪而直接驅動負載,減少了中間的動力傳動環(huán)節(jié)。直驅電機相對于傳統(tǒng)的伺服電機的優(yōu)點是：能在低速旋轉時輸出很大扭矩,從而可以不通過減速齒輪而直接驅動低速生產(chǎn)設備,有很高的社會實際應用價值。為了簡化數(shù)控轉塔刀架結構、大幅度地提高其綜合性能,本論文將這種技術應用于數(shù)控轉塔刀架上。本論文的主要研究內(nèi)容如下:
第一、了解數(shù)控轉塔刀架的國內(nèi)外研究現(xiàn)狀,研究國內(nèi)外各種刀架的機械結構,分析直驅伺服電機和其他伺服電機相比的優(yōu)點以及其驅動刀架的可行性。
第二、根據(jù)直驅伺服電機自身的結構和功能特點,設計一種直驅數(shù)控臥式轉塔刀架。并對其進行設計,包括轉位機構、定位機構、密封裝置、控制裝置等。
第三、對轉塔刀架的松開與鎖緊機構進行設計,主要是對轉塔刀架的液壓缸缸體進行設計,計算液壓缸的相關參數(shù)。
第四、對數(shù)控轉塔刀架進行二維建模,首先用二維軟件Autocad對其進行各個關鍵件的繪制，然后按照裝配關系把轉塔刀架裝配起來，經(jīng)過驗證合格后，可用作零件圖交付工廠實施加工。
關鍵詞：數(shù)控；轉塔刀架；伺服電機；永磁同步交流伺服電機
III
design of Turret tool post and study of related technologies
Abstract：CNC turret pagoda as one of the core features of a lathe to measure the quality of its performance directly affects the machining precision and efficiency of the lathe. With the development of technology and servo motors, servo motors gradually replaced the traditional coarse positioning CNC turret on signal transmission and other devices, greatly simplifies the turret structure, greatly improving the reliability of the knife holder, and significantly reducing tool change time and improve the overall performance of the tool holder. However, since the conventional servo motors commonly used in low-speed torque characteristics well, so when using the reduction gear mechanism must be used to meet the high torque at low speed turret rotation generated. Drive the motor unit directly is not directly driven by the intermediate gear and load, reducing the intermediate power transmission link. Direct drive motor with respect to the advantages of traditional servo motor is: can output a large torque at low speed, there by directly driving low-speed production equipment without going through reduction gear, has a high social value of practical application. In order to simplify the structure of CNC turret, greatly improve their overall performance, this paper will apply the technology on CNC turret. The main contents of this paper are as follows:
Firstly, study the situation of the CNC turret tool post, study the structure of some CNC turret tool post at home and abroad, analyze the characteristics、applications、advantages and disadvantages of various structure, analyze the characteristics of direct-drive servomotor and the feasibility to drive the turret.
Secondly, learn from the structure of CNC turret tool post at home and abroad, according to the direct-drive servomotor's own structure and characteristics, design a horizontal CNC turret tool post, including detent mechanism, control devices, sealing device etc..
Thirdly, the turret and release the locking mechanism designed mainly for turret cylinder block design, calculation of cylinder parameters.
Fourth, CNC turret two-dimensional modeling, the first two-dimensional drawing software Autocad its various key member, and then follow the relationship between the turret assembly is assembled, after verification of qualified, can be used Spare delivery factory implementation process.
Keywords: brick turret；servo motor；permanent magnet synchronous AC servo motor
目 錄
摘要 I
Abstract II
目錄 IV
1 緒論 1
1.1 課題研究背景 1
1.2 轉塔刀架的國內(nèi)外研究現(xiàn)狀 1
1.2.1 國內(nèi)研究現(xiàn)狀 1
1.2.2 國外研究現(xiàn)狀 2
1.3 主要研究內(nèi)容和意義 3
1.3.1 主要的研究內(nèi)容 3
1.3.2 研究意義 3
2 轉塔刀架的研究方案 4
2.1 刀架的基本分類 4
2.2 刀架設計基本要求 4
2.3 轉塔刀架的方案研究 5
2.3.1 動力裝置的選擇 4
2.3.2 主軸部件 6
2.3.3 裝刀機構 6
2.3.4 分度、定位機構 7
2.3.5 精定位機構 8
2.3.6 轉塔刀架的密封 9
2.3.7 動力傳動機構 10
2.4 轉塔刀架的整體設計 10
3 轉塔刀架的鎖緊與松開技術 12
3.1 液壓的鎖緊與松開的基本控制原理 12
3.2 液壓缸的設計 13
3.2.1 活塞缸的類型 13
3.2.2 缸筒的計算設計 14
3.3 活塞的計算設計 14
3.4 密封裝置的設計 15
4 轉塔刀架的二維模型的建立 17
4.1 AUTOCAD簡介 17
4.2 轉塔刀架二維模型的建立 17
總結 20
參考文獻 19
致謝 21
7
1 緒論
1.1 課題研究背景
數(shù)控轉塔刀架是加工中心、數(shù)控車床必備的機床附件，是數(shù)控車床上的核心功能部件之一，尤其適用全功能數(shù)控車床。作為關鍵附件，高性能的數(shù)控轉塔刀架對于提高機床整體運行的可靠性、穩(wěn)定性和效率有著重要意義，數(shù)控轉塔刀架是由數(shù)控系統(tǒng)來控制的，因此，在轉塔刀架本身性能提高的情況下，如何實現(xiàn)控制任務就顯得十分重要了［1］。
1.2 轉塔刀架的國內(nèi)外研究現(xiàn)狀
1.2.1 國內(nèi)研究現(xiàn)狀
目前國內(nèi)主要刀架產(chǎn)品生產(chǎn)廠家有:煙臺環(huán)球、常州宏達、常州亞興、臺灣六鑫、臺灣德士、臺灣亙陽、沈陽精誠等。經(jīng)過近幾年的發(fā)展,國內(nèi)及時跟蹤國外先進技術,不斷開發(fā)推出新產(chǎn)品,刀架技術得到了很大提高。
煙臺環(huán)球公司研制的AK系列刀架采用伺服電機進行分度,液壓控制松開,以端齒輪(三聯(lián)齒輪)進行精密定位,可實現(xiàn)雙向轉位和任意刀位就近選刀,最快轉位時間,中心高有、和,刀孔的定位精度達,重復定位精度達,轉位的分度時間達到
外文原文：
Passage A Power Train
The power train serves two functions: it transmits power from the engine to the drive wheels, and it varies the amount of torque. The power train includes:1.engine:that produces power;2.transmission:either manual or automatic;3.clutch:used only on manual transmission, or torque converter: used only on automatic transmission;4.drive shaft: that transmits the power from transmission to differential;5.that carries the power to the two wheel axles.See Fig.5-1.
Manual transmission
The function of a manual transmission, shown in Fig.5-2,is to transfer engine power to the drive shaft and rear wheels. Gears inside the transmission change the car’s drive-wheel speed and torque in relation to engine speed and torque. This keeps the engine’s output matched as close as possible to varying road speeds and loads.
A manual transaxle, shown in the Fig.5-3.，is a single unit composed of a manual ansmission, differential, and drive axles. Most front-wheel-drive（FWD） cars are equipped with a transaxle. Such transaxle are also found on some front-engined or rear-wheel-drive（RWD）,four-wheel-drive（4WD）cars and on rear-engined and rear-wheel-drive cars．
A manual transmission requires use of a clutch to apply and remove engine torque to the transmission input shaft. The clutch allows this to happen gradually so that the car can be started from a complete stop.
Manual transmission usually have four or five speeds, and often have "overdrive", which means that the output shaft can turn faster than the input Shaft for fuel economy on the highway.When you use it, it will reduce the engine speed by one-third, while maintaining the same road speed.
Clutch
Driving a car with a manual transmission, you depress the clutch, select a gear, and release the clutch while applying power to get the car to move.The clutch allows engine power to be applied gradually when a vehicle is starting out,and interrupts power to avoid gear crunching when shifting.Engaging the clutch allows power to transfer from the engine to transmission and drive wheel.Disengaging the clutch stops the power transfer and allows the engine to continue turning without force to the drive wheels.
The clutch basic components are:the flywheel,clutch disk,pressure plate,release bearing and linkage.See Fig.5-4.
The flywheel is bolted to the crankshaft of the engine.Its main function is to transfer engine torque from the engine to the transmission.
The clutch disk is basically a steel plate,covered with a frictional material that goes between the flywheel and the pressure plate.
A pressure plate is bolted to the flywheel.It includes a sheet metal cover,heavy release springs,a metal pressure ring that provides a friction surface for the clutch disk.
The release bearing is the heart of clutch operation.When the clutch pedal is depressed,the throw-out bearing moves toward the flywheel,pushing in the pressure plate’s release fingers and moving the pressure plate fingers or levers against pressure plate spring force.
The linkage transmits and multiplies the driver’s leg force to the fork of the clutch pressure plate.A mechanical clutch linkage usually consists of the clutch pedal,a series of linkage rods and arms,or a cable.A hydraulic clutch linkage typically includes a clutch master cylinder and reservoir,a hydraulic line and a slave cylinder.
Automatic transmission
Both an automatic transmission and a manual transmission accomplish exactly the same thing,but they do it in totally different ways.The key difference between a manual and an automatic transmissions is that the manual transmission locks and unlocks and different sets of gears to the output shaft to achieve the various gear ratios,while in an automatic transmission,the same set of gears produces all of different gear ratios.The planetary gear-set is the device that makes this possible in an automatic.
Automatic transmissions are used in many rear-wheel-drive and four-wheel-drive vehicles.Automatic transaxles are used in most front-wheel-drive vehicles.The major components of a transaxle are the same as those in a transmission,except the transaxle assembly includes the final drive and differential gears,in addition to the transmission.
An automatic transmission receives engine power through a torque converter,which is driven by the engine’s crankshaft.Hydraulic pressure in the converter allows power to flow from the torque converter to the transmission’s input shaft.The input shaft drives a planetary gear set that provides the different forward gears,a neutral position,and one reverse gear.Power flow through the gears is controlled by multiple-disk clutches,one-way clutches,and friction bands.
Passage B Power Train
Torque Converter
The key to the modern automatic transmission is the torque converter.It takes the place of a clutch in a manual transmission to send the power from the engine to the transmission input shaft.The torque converter offers the advantage of multiplying the turning power provided by the engine.
It has three parts that help multiply the power:an impeller（or pump）conn cted to the engine’s crankshaft,a turbine to turn the turbine shaft which is connected to the gears,and a stator（or guide wheel）between the two.See Fig. 5-6.
The torque converter is filled with transmission fluid that is moved by impeller blades.When the impeller spins above a certain speed,the turbine spins,driven by the impeller.
Planetary Gearing
Planetary gears provide for the different gear ratios needed to move a vehicle in the desired direction at the correct speed.A planetary gear set consists of a sun gear,planet gears,and a internal ring.See Fig. 5-7.
In the center of the planetary gear set is the sun gear.Planet gears surround the sun gear,just like the earth and other planets in our solar system.These gears are mounted and supported by the planet carrier and each gear spins on its own separate shaft.The planet gears are in constant mesh with the sun and ring gears.The ring gear is the outer gear of the gear set.Its has internal teeth and surrounds the rest of the gear set.Its gear teeth are in constant mesh with the planet gears.The number of planet gears used in a planetary gear set varies according to the loads the transmission is designed to face.For heavy loads,the number of planet gears is increased to spread the work load over more gear teeth.
The planetary gear set can provide a gear reduction or overdrive,direct drive or reverse,or a neutral position.Because the gears in constant mesh,gear changes are made without engaging or disengaging gears,as is required in a manual transmission.Rather, clutches and bands are used to either hold or release different members of the gear set to get the proper direction of rotation and/or gear ratio.
Different
On FWD cars,the differential unit is normally part of the transaxle assembly.On RWD cars,it is part of the rea axle assembly.Located inside the differential case are the differential pinion shafts and gears and the differential side gears. See Fig.5-8
The differential assembly revolves with the ring gear.Axle side gears are splined to the rear axle or front axle drive shafts.
When an automobile is moving straight ahead,both wheels are free to rotate. Engine power is applied to the pinion gear,which rotates the ring gear.Beveled pinion gears are carried around by the ring gear and rotate as one unit.Each axle receives the same power,so each wheel turns at the same speed. See Fig. 5-9.
When the car turns a sharp corner,only one wheel rotates freely.Torque still comes in on the pinion gear and rotates the ring gear,carrying the beveled pinions around with it.However,one axle is held stationary and the beveled pinions are forced to rotate on their own axis and "walk around"their gear.The other side is forced to rotate because it is subjected to the turning force of the ring gear,which is transmitted through the pinions. See Fig. 5-10.
Drive shaft
A drive shaft and universal joints（U-joints） connect the transmission to the rear drive axle on most rear-wheel-drive vehicles.Many four-wheel-drive vehicles also use drive shafts and universal joints,with one drive shaft between the transfer case and rear drive axle and a second drive shaft between the transfer case and the front drive axle. The drive shaft is sometimes called a propeller shaft.
The drive shaft and U-joints provide a means of transferring engine torque to drive axles.The universal joints allow the drive shaft to move up and down,to allow for suspension travel.Some drive shaft also have a slip joints that allows the drive shaft to make minor length changes as the vehicle suspension height changes.
Gears and gear drive
Gears are the most durable and rugged of all mechanical drives.They can transmit high power at efficiencies up to 98% and with long service lives. For this reason, gears rather than belts or chains are found in automotive transmissions and most heavy-duty machine drives. On the other hand, gears are more expensive than other drives, especially if they are machined and not made from power metal or plastic.
Gear cost increases sharply with demands for high precision and accuracy. So it is important to establish tolerance requirements appropriate for the application. Gears that transmit heavy loads or than operate at high speeds are not particularly expensive, but gears that must do both are costly.
Silent gears also are expensive. Instrument and computer gears tend to be costly because speed or displacement ratios must be exact. At the other extreme, gears operating at low speed in exposed locations are normally termed no critical and are made to minimum quality standards.
For tooth forms, size, and quality, industrial practice is to follow standards set up by the American Gear Manufactures Association (AGMA).
Tooth form
Standards published by AGMA establish gear proportions and tooth profiles. Tooth geometry is determined primarily by pitch, depth, and pressure angle.
Pitch：Standards pitches are usually whole numbers when measured as diametral pitch P. Coarse-pitch gearing has teeth larger than 20 diametral pitch –usually 0.5 to 19.99. Fine-pitch gearing usually has teeth of diametral pitch 20 to 200.
Depth: Standardized in terms of pitch. Standard full-depth have working depth of 2/p. If the teeth have equal addenda(as in standard interchangeable gears) the addendum is 1/p. Stub teeth have a working depth usually 20% less than full-depth teeth. Full-depth teeth have a larger contract ratio than stub teeth. Gears with small numbers of teeth may have undercut so than they do not interfere with one another during engagement. Undercutting reduce active profile and weakens the tooth.
Mating gears with long and short addendum have larger load-carrying capacity than standard gears. The addendum of the smaller gear (pinion) is increased while that of larger gear is decreased, leaving the whole depth the same. This form is know as recess-action gearing.
Pressure Angle: Standard angles areand.Earlier standards include a 14-pressure angle that is still used. Pressure angle affects the force that tends to separate mating gears. High pressure angle decreases the contact ratio (ratio of the number of teeth in contact) but provides a tooth of higher capacity and allows gears to have fewer teeth without undercutting.
Backlash: Shortest distances between the non-contacting surfaces of adjacent teeth .
Gears are commonly specified according to AGMA Class Number, which is a code denoting important quality characteristics. Quality number denote tooth-element tolerances. The higher the number, the closer the tolerance. Number 8 to 16 apply to fine-pitch gearing.
Gears are heat-treated by case-hardening, through-hardening, nitriding, or precipitation hardening. In general, harder gears are stronger and last longer than soft ones. Thus, hardening is a device that cuts the weight and size of gears. Some processes, such as flame-hardening, improve service life but do not necessarily improve strength.
Design checklist
The larger in a pair is called the gear, the smaller is called the pinion.
Gear Ratio: The number of teeth in the gear divide by the number of teeth in the pinion. Also, ratio of the speed of the pinion to the speed of the gear. In reduction gears, the ratio of input to output speeds.
Gear Efficiency: Ratio of output power to input power. (includes consideration of power losses in the gears, in bearings, and from windage and churning of lubricant.)
Speed: In a given gear normally limited to some specific pitchline velocity. Speed capabilities can be increased by improving accuracy of the gear teeth and by improving balance of the rotating parts.
Power: Load and speed capacity is determined by gear dimensions and by type of gear. Helical and helical-type gears have the greatest capacity (to approximately 30,000 hp). Spiral bevel gear are normally limited to 5,000 hp, and worm gears are usually limited to about 750 hp.
Special requirements
Matched-Set Gearing: In applications requiring extremely high accuracy, it may be necessary to match pinion and gear profiles and leads so that mismatch does not exceed the tolerance on profile or lead for the intended application.
Tooth Spacing: Some gears require high accuracy in the circular of teeth. Thus, specification of pitch may be required in addition to an accuracy class specification.
Backlash: The AMGA standards recommend backlash ranges to provide proper running clearances for mating gears. An overly tight mesh may produce overload. However, zero backlash is required in some applications.
Quiet Gears: To make gears as quit as possible, specify the finest pitch allowable for load conditions. (In some instances, however, pitch is coarsened to change mesh frequency to produce a more pleasant, lower-pitch sound.) Use a low pressure angle. Use a modified profile to include root and tip relief. Allow enough backlash. Use high quality numbers. Specify a surface finish of 20 in. or better. Balance the gear set. Use a nonintegral ratio so that the same teeth do not repeatedly engage if both gear and pinion are hardened steel. (If the gear is made of a soft material, an integral ratio allows the gear to cold-work and conform to the pinion, thereby promoting quiet operation.) Make sure critical are at least 20% apart from operating speeding or speed multiples and from frequency of tooth mesh.
Multiple mesh gear
Multiple mesh refers to move than one pair of gear operating in a train. Can be on parallel or nonparallel axes and on intersection or nonintersecting shafts. They permit higer speed ratios than are feasible with a single pair of gears .
Series trains:Overall ratio is input shaft speed divided by output speed ,also the product of individual ratios at each mesh ,except in planetary gears .Ratio is most easily found by dividing the product of numbers of teeth of driven gears by the product of numbers of teeth of driving gears.
Speed increasers (with step-up rather than step-down ratios) may require special care in manufacturing and design. They often involve high speeds and may creste problems in gear dynamics. Also, frictional and drag forces are magnified which, in extreme cases , may lead to operational problems.
Epicyclic Gearing:Normally, a gear axis remains fixed and only the gears rotates. But in an epicyclic gear train, various gears axes rotate about one anther to provide specialized output motions. With suitable clutchse and brakes, an epicyclic train serves as the planetary gear commonly found in automatic transmissions.
Epicyclic trains may use spur or helical gears, external or internal, or bevel gears. In transmissions, the epicyclic (or planetary) gears usually have multiple planets to increase load capacity.
In most cases, improved kinematic accuracy in a gearset decreases gear mesh excitation and results in lower drive noise. Gearset accuracy can be increased by modifying the tooth involute profile, by substituting higher quality gearing with tighter manufacturing tolerances, and by improving tooth surface finish. However, if gear mesh excitation generaters resonance somewhere in the drive system, nothing short of a “perfect” gearset will substantially reduce vibration and noise.
Tooth profiles are modified to avoid interferences which can result from deflections in the gears, shafts, and housing as teeth engage and disendgage. If these tooth interferences are not compensated for by profile modifications, gears load capacity can be seriously reduced. In addition, the drive will be noisier because tooth interferences generate high dynamic loads. Interferences typically are eliminated by reliving the tooth tip, the tooth flank, or both. Such profile modifications are especially important for high-load , high-speed drives. The graph of sound pressure levelvs tip relief illustrates how tooth profile modifications can affect overall drive noise. If the tip relief is less than this optimum value, drive noise increases because of greater tooth interference; a greater amount of tip relief also increase noise because the contact ratio is decreased.
Tighter manufacturing tolerances also produce quietier gears. Tolerances for such parameters as profile error, pitch AGMA quality level. For instance, the graph depicting SPL vs both speed and gear quality shows how noise decreases example, noise is reduced significantly by an increase in accuracy from an AGMA Qn 11 quality to an AGNA Qn 15 quality. However, for most commercial drive applications, it is doubtful that the resulting substantial cost increase for such an accuracy improvement can be justified simply on the basis of reduced drive noise.
Previously, it was mentioned that gears must have adequate clearance when loaded to prevent tooth interference during the course of meshing. Tip and flank relief are common profile modifications that control such interference. Gears also require adequate backlash and root clearance. Noise considerations make backlash an important parameter to evaluate during drive design. Sufficient backlash must be provided under all load and temperature conditions to avoid a tight mesh, which creates excessively high noise level. A tight mesh due to insufficient backlash occurs when the drive and coast side of a tooth are in contact simultaneously. On the other hand, gears with excessive backlash also are noisy because of impacting teeth during periods of no load or reversing load. Adequate backlash should be provided by tooth thinning rather than by increase in center distance. Tooth thinning dose not decrease the contact ratio, whereas an increase in center distance does. However, tooth thinning does reduce the bending fatigue, a reduction which is small for most gearing systems.
中文譯文：
動力傳動系A
動力傳動系有兩個作用：它把動力從發(fā)動機傳送到驅動輪上，并且改變扭矩的大小。動力傳動系包括：1.發(fā)動機：制造動力；2.變速器：不是手動就是自動；3.離合器：僅用在手動變速器或者液力變矩器；4.驅動軸：把動力從變速器傳到差速器；5.差速器：將動力傳到兩個驅動軸上。
手動變速器
手動變速器的作用是，把發(fā)動機動力傳送到傳動軸和驅動輪。變速器內(nèi)的齒輪，改變車輛驅動輪和發(fā)動機之間轉速和扭矩的比例。這樣保持發(fā)動機的輸出盡可能的靠近改變路面速度和最低速度。
一個手動的驅動橋，是一個由手動變速器，差速器，傳動軸組成的。大多數(shù)前輪驅動汽車裝有一個驅動橋。這樣的驅動橋也能在一些前置引擎或者后輪驅動，四輪驅動的汽車，在后置引擎和后輪驅動的汽車上看到。
一個手動變速器包括使用一個離合器來消除發(fā)動機扭矩到變速器輸入軸。離合器允許這樣漸漸發(fā)生以至于汽車能夠啟動。
手動變速器通常有四到五個檔位，而且一般有“超速檔”，對于在路上的燃油經(jīng)濟性這樣就意味著輸出軸比輸入軸轉的更快。當你使用變速器的時候，要維持同樣的速度，將減少發(fā)動機轉速的三分之一。
離合器
駕駛手動擋汽車，你踩下離合器，嚙合了齒輪，然后松掉離合器而汽車會適應動力前進。離合器可使車輛啟動后發(fā)動機的動力被逐漸的加載，并可通過切斷動力防止換擋時齒輪被咬碎。離合器嚙合時把發(fā)動機動力傳送到變速器和驅動輪。離合器分離停止動力傳輸，在沒有動力傳到驅動輪上的情況下，發(fā)動機可以持續(xù)運轉。
離合器基本的部件是：飛輪，離合器盤，壓力盤，分離軸承和聯(lián)接裝置。
飛輪被螺栓固定在發(fā)動機的曲軸上。它的主要作用是傳送發(fā)動機扭矩從發(fā)動機到變速器。
離合器盤基本就是一塊鋼板，在飛輪和壓力盤中間覆蓋了一種耐摩擦材料。
離合器盤螺栓連接在飛輪上。它包括一張薄片金屬封蓋，彈簧，一個給離合器盤提供摩擦表面的金屬壓力環(huán)。
分離軸承是離合器操縱機構的中心。當離合器踏板踩下時，分離軸承指向飛輪，壓盤推進釋放了擋板然后移動壓盤彈簧片到壓盤彈簧彈力頂。
聯(lián)接裝置成倍地傳送駕駛員腿部力量到離合器壓盤的膜片。一個機械離合器連接裝置通常由離合器踏板，一系列連接桿臂或者一組電纜。一個液壓離合器聯(lián)接裝置大體上是由一個離合器制動缸和儲存器，一組液壓管路和一個從動缸。
自動變速器
自動變速器和手動變速器嚴格的講都能完成一樣的工作，但他們完成工作的方法完全不一樣。手動變速器和自動變速器的之間的根本區(qū)別在于手動變速器鎖與不鎖在不同的輸出軸來實
收藏