人力提升機傳動方案的擬定與分析計算設(shè)計【含圖紙】

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The design of the structure is the traditional combination of innovative ideas and results. Human elevator has no patent in China, more electricity and power lift hoist have been used. This design is mainly taking into account the implementation of function, size limits,structure, simple operation.mechanical principles and mechanical design is based on the theoretical knowledge, Worm gear drive mechanism, Screw drive as well as several other detailed analysis of common institutions, Choose the appropriate option.The principle according to clutch the clutch mode and select the appropriate bodies Learned to use engineering graphics and three-dimensional mapping of knowledge UG draw assembly drawings, and parts diagram. The design includes a gear drive, second gear, wire rope around the law, the design of the clutch, fan gear, self-locking worm and worm. Take the initiative and drive shaft gear shaft gear mesh on the pedal force and the moment passed on to the output shaft. Output shaft of the gear teeth and then sets of force and torque delivered to the tank through the gear wheel, the drive sheave rotation, then driven gears meshing with the bottom of the tank below the rotating wheel,Re-engagement with the bottom of the drive gear wheel rotation slot below, the use of wire rope and there is no relative slip between the sheaves to drive the entire machine using steel wire rope move up and down. Keywords: hoist；gear ；transfer motion;worm;self-locking; V 目 錄 摘 要 .III ABSTRACT .IV 目 錄 .V 1 緒論 .1 1.1 本課題的研究內(nèi)容和意義 .1 1.2 國內(nèi)外的發(fā)展概況 .1 1.3 本課題應(yīng)達到的要求 .1 2 方案擬定 .3 3 功能原理及運動特點 .5 3.1 功能原理 .5 3.2 運動特點 .7 4 確定傳動裝置的總傳動比和分配傳動比 .9 4.1 確定總傳動比 .9 4.2 分配傳動比 .9 4.3 各軸運動和動力參數(shù)確定 .9 4.3.1 各軸轉(zhuǎn)速 .9 4.3.2 各軸輸入功率 .9 4.3.3 各軸輸出功率 .9 4.3.4 各軸輸入轉(zhuǎn)矩 .9 5 選擇鋼絲繩型號 .11 6 齒輪、棘輪的設(shè)計 .13 6.1 主動軸上齒輪傳動的設(shè)計計算 .13 6.1.1 齒輪材料，熱處理及精度 .13 6.1.2 初步設(shè)計齒輪傳動的主要尺寸 .13 6.1.3 設(shè)計計算 .14 6.1.4 齒根彎曲疲勞強度設(shè)計 .15 VI 6.2 從動輪上齒輪傳動的設(shè)計和計算 .17 6.2.1 齒輪材料，熱處理及精度 .17 6.2.2 初步設(shè)計齒輪傳動的主要尺寸 .18 6.2.3 設(shè)計計算 .18 6.2.4 齒根彎曲疲勞強度設(shè)計 .20 6.3 棘輪的設(shè)計 .22 6.3.1 棘輪機構(gòu)的基本結(jié)構(gòu)和工作原理 .22 6.3.2 棘輪裝置的優(yōu)缺點 .22 6.3.3 棘輪機構(gòu)中的主要問題 .22 6.3.4 棘輪幾何尺寸的計算 .22 7 軸、軸承和軸鍵的設(shè)計和校核 .25 7.1 主動軸的設(shè)計校核 .25 7.1.1 選擇軸的材料 .25 7.1.2 初步計算軸的最小直徑 .25 7.1.3 軸的結(jié)構(gòu)設(shè)計 .26 7.1.4 按彎矩合成力校核軸的強度 .26 7.2 從動軸的設(shè)計校核 .29 7.2.1 輸入軸上的功率、轉(zhuǎn)速及轉(zhuǎn)矩 .29 7.2.2 初步確定軸的最小直徑 .29 7.2.3 軸的結(jié)構(gòu)設(shè)計 .29 7.2.4 按彎矩合成力校核軸和強度 .30 7.3 滾動軸承的選擇與校核 .35 7.3.1 主動軸軸承的型號選擇和設(shè)計 .35 7.3.2 中間軸滾動軸承的型號選擇和計算 .37 8 箱體結(jié)構(gòu)設(shè)計 .39 8.1 主體設(shè)計 .39 8.2 對附件設(shè)計 .39 9 結(jié)論與展望 .43 9.1 結(jié)論 .43 VII 9.2 不足之處與未來展望 .43 致謝 .45 參考文獻 .46 人力提升機傳動方案的擬定與計算設(shè)計 1 1 緒論 1.1 本課題的研究內(nèi)容和意義 隨著我國建筑行業(yè)的發(fā)展，住宅建筑、高層建筑越來越多，外墻涂層、裝飾以及物 業(yè)管理清洗所需要的高處作業(yè)人力提升機已被廣大用戶所采用，同時人力提升機也成為 了野外電力設(shè)備安裝的專用設(shè)備。人力可輕松操縱上下輸送物料和人員填補該產(chǎn)品系列 中的缺失在無電源供應(yīng)的情況下。使用人力提升機省工、省費用、安全，大大減輕了工 人勞動強度，提高了施工進度。 1.2 國內(nèi)外的發(fā)展概況 人力提升機在國內(nèi)尚無申請專利，運用較多的是電力提升機和電力升降機。據(jù)統(tǒng)計， 使用人力提升機施工，其施工費用僅為腳手架的 70%，生產(chǎn)率是腳手架的三倍，但是由 于多種原因建筑施工中高處業(yè)人力提升機墜落事故時有發(fā)生，這不僅造成人生傷亡，經(jīng) 濟損失和社會影響，而對高處作業(yè)人力提升機使用日益增多的今天，人力提升機的質(zhì)量 成為關(guān)注的焦點，這就要求從事高處作業(yè)提升機的設(shè)計制造部門應(yīng)該加強產(chǎn)品安全性能 的開發(fā)，同時確定人力提升機產(chǎn)品安全質(zhì)量標(biāo)準(zhǔn)，規(guī)范國內(nèi)市場。必須保證人力提升機 安裝后符合安裝要求，加大對施工人員的安全培訓(xùn)，以確保安全。 1.3 本課題應(yīng)達到的要求 人力提升的總重量為 350 kg,提升速度 5m/min。將輸入軸上腳踏的力和力矩傳遞到輸 出軸上。輸出軸帶動槽輪轉(zhuǎn)動，利用鋼絲繩與槽輪之間沒有相對滑動，從而利用驅(qū)動整 個機器在鋼絲繩上下移動。 無錫太湖學(xué)院學(xué)士學(xué)位論文 2 2 方案擬定 方案一:由葫蘆想到滑輪組結(jié)構(gòu)，利用鋼絲繩繞在滑輪組上由繩帶動整個機器實現(xiàn)上 下移動。傳動：滑輪組上的齒輪跟輸出軸上的齒輪嚙合傳動，依次一系列的齒輪嚙合實 現(xiàn)從主動軸（人力腳踏動力）到輸出軸再到滑輪組上的齒輪傳遞動力。制動：兩個蝸桿 自鎖的原理（螺旋升角小于當(dāng)量摩擦角）阻止滑輪組的轉(zhuǎn)動。 方案二：采用鏈傳動，將主動軸上的力通過鏈條傳遞到輸出軸上，制動采用棘輪機 構(gòu)制動 方案三：通過齒輪嚙合傳動，通過齒輪的二級傳動，將主動軸上的輸入力放大，制 動采用棘輪機構(gòu)。 通過計算對比上述三個方案的優(yōu)劣： 方案一采用蝸桿自鎖的原理，蝸桿傳動與螺旋齒輪傳動相似在嚙合處有相對滑動。 當(dāng)滑動速度很大，工作條件不夠良好時會產(chǎn)生嚴(yán)重的摩擦與磨損，從而引起過分發(fā)熱， 使?jié)櫥闆r惡化，因此摩擦損失較大，效率底，當(dāng)傳動具有自鎖性時效率僅為 0.4 左右。 方案二：采用鏈傳動，優(yōu)點是可以降低成本，整體尺寸較小，結(jié)構(gòu)較為緊湊，但鏈 傳動不能保持恒定的瞬時傳動比；磨損易發(fā)生跳齒，工作時有噪聲，不宜用在載荷變化 很大和急速反轉(zhuǎn)的場合。 方案三：采用齒輪傳動提高了效率，同時采用棘輪制動，有效的減小了整體尺寸。 綜上所述采用方案三。 人力提升機傳動方案的擬定與計算設(shè)計 3 3 功能原理及運動特點 3.1 功能原理 如圖 3.1 所示為人力提升機裝配圖。本機構(gòu)是一種升降機裝置，主要由三部分組成： 1.傳動部分；2.繞線部分；3.制動部分。 無錫太湖學(xué)院學(xué)士學(xué)位論文 4 圖 3.1 裝配圖 圖 3.2 傳動系統(tǒng)圖 人力提升機傳動方案的擬定與計算設(shè)計 5 如圖 3.2 所示傳動部分主要是在主軸箱內(nèi)，如圖二所示，由主動軸 3、從動軸 4、齒 輪 3、棘輪機構(gòu) 11、齒輪 12、擋圈 14、以及齒輪 1 組成。主動軸 3 和腳踏連接，可以由 人直接驅(qū)動。在工作狀態(tài)，主動軸上的齒輪 1 同時帶動裝在從動軸上的齒輪 12 轉(zhuǎn)動，齒 輪 12 與軸采用螺紋連接，齒輪 12 正轉(zhuǎn)壓緊棘輪 11，帶動軸轉(zhuǎn)動，齒輪 3 再與大齒輪嚙 合傳動，再通過繞線部分參照圖 1，主要由兩個大齒輪，兩個壓緊輪裝置 7，防護罩 4， 彈簧 3 和彈簧 6 以及殼體組成，鋼絲繩繞在兩個齒輪的繞線槽中。齒輪的繞線槽的截面 成梯形狀，鋼絲繩在其中越壓越緊，從而保證鋼絲繩與齒輪之間沒有相對滑動，即不會 打滑。兩個壓緊輪裝置 7 控制了鋼絲繩在線槽中的包角，從而確定了此部分的傳動效率。 防護罩 4 能保證在齒輪 5 上穿鋼絲繩順利進行，并且可以防止當(dāng)繩處于松弛狀態(tài)時，跑 出繞線槽。 制動部分主要有：圖 2 中棘輪機構(gòu) 11 和齒輪 12 組成，當(dāng)提升重物時，主動軸上的 齒輪 1 與從動軸上的齒輪 12 嚙合，齒輪 12 與軸螺紋連接壓緊棘輪帶動從動軸轉(zhuǎn)動，當(dāng) 主動軸停止時，棘輪受到棘爪的作用逆止，當(dāng)齒輪 12 反轉(zhuǎn)時，將棘輪松開，齒輪 12 被 擋圈擋住時，帶動軸反轉(zhuǎn)將重物放下，當(dāng)主動軸停轉(zhuǎn)時，由于重物的作用使軸反轉(zhuǎn)，使 棘輪被壓緊制動。 3.2 運動特點 該升降機主要能實現(xiàn)二個功能：第一，人踩著腳踏能往上走，不踩的時候能自鎖停 在原位；第二，人反踩腳踏能往下走，不踩的時候能自鎖停在原位；以下我將介紹實現(xiàn) 這些功能的原理： 第一種功能的實現(xiàn)原理是：當(dāng)人踩腳踏時，踩腳踏的力通過一系列齒輪傳動放大到 足以克服整個升降機的重力，從而能往上走。當(dāng)人不踩腳踏時，在棘輪機構(gòu)作用的情況 下，克服了整個機器的重力，從而使得升降機停在原位。 第二種功能的實現(xiàn)原理與第一種一樣。 無錫太湖學(xué)院學(xué)士學(xué)位論文 6 4 確定傳動裝置的總傳動比和分配傳動比 4.1 確定總傳動比 根據(jù)提升機的提升速度為 5m/s,根據(jù)經(jīng)驗初定槽輪直徑為 110mm min/418.05.143260rRvn （4.1） 根據(jù)經(jīng)驗假設(shè)人蹬腳踏的速度為 70r/min，則總的傳動比為 8.41. 7nima （4.2） 4.2 分配傳動比 ai0i （4.3） 式中 分別為一級齒輪和二級齒輪的傳動比。為使一級齒輪結(jié)構(gòu)不過大，0,i 初步取 1.47 ，則二級齒輪傳動比為 i 3.302 （4.4）0/a 4.3 各軸運動和動力參數(shù)確定 4.3.1 各軸轉(zhuǎn)速 70/1.4747.619r/min n0/im （4.5） 47.619/3.30214.421r/mn1/i 4.3.2 各軸輸入功率 0.1kWdP 2 0.10.980.990.097kW Ip3 （4.6） 2 0.0970.990.970.093WI3 24=0.0930.990.960.085kWP 4.3.3 各軸輸出功率 0.98=0.095 kW (4.7) 0.98=0.091kW 人力提升機傳動方案的擬定與計算設(shè)計 7 0.98=0.086kWP 4.3.4 各軸輸入轉(zhuǎn)矩 = Nm (4.8)1Td0i1 主動軸的輸出轉(zhuǎn)矩 =9550 =95500.1/70=13.64Nm （4.9）dmdnP 所以: =13.641.470.96= 19.25NmT0i1 =19.253.3020.980.95=59.14Nm2 = =59.140.950.97=54.50Nm34 輸出轉(zhuǎn)矩： 0.98=18.87 Nm （4.10） T 0.98=57.97 Nm 0.98=53.41Nm 表 4-1 運動和動力參數(shù) 功率 P KW 轉(zhuǎn)矩 T Nm 軸名 輸入 輸出 輸入 輸出 轉(zhuǎn)速 r/min 主動軸 0.1 13.64 70 1 軸 0.097 0.095 19.25 18.87 47.62 2 軸 0.093 0.091 59.14 57.96 14.42 3 軸 0.088 0.086 54.50 53.41 14.42 無錫太湖學(xué)院學(xué)士學(xué)位論文 8 5 選擇鋼絲繩型號 根據(jù)機械設(shè)計手冊第五版第 2 卷第 11 章 2、1、3 鋼絲繩直徑的計算與選擇選用鋼絲繩 的直徑。 鋼絲繩直徑可由鋼絲繩最大工作靜拉力按式 d= sc （5.1） d -鋼絲繩最小直徑 mm， C -選擇系數(shù) mm/ 2 1N S -鋼絲繩最大工作靜拉力 由表 8-1-15 可查的 C=0.140 安全系數(shù)為 9，由提升機重量為 350kg d =0.140 x =8.3 10 x35 （5.2） 再由 2.1.5 一般用途鋼絲繩中，適用于機械建筑貨用索道等行業(yè)使用的各種圓股鋼絲 繩,可選用鋼絲繩 6X37(b)類 典型結(jié)構(gòu)為 6X37(1+6+12+18) 人力提升機傳動方案的擬定與計算設(shè)計 9 6 齒輪、棘輪的設(shè)計 6.1 主動軸上齒輪傳動的設(shè)計計算 6.1.1 齒輪材料，熱處理及精度 考慮此減速器的功率及現(xiàn)場安裝的限制，故大小齒輪都選用硬齒面漸開線斜齒輪 （1) 齒輪材料及熱處理 材料：高速級小齒輪選用 鋼調(diào)質(zhì)，齒面硬度為小齒輪 280HBS 取小齒輪齒數(shù)45 =171Z 高速級大齒輪選用 鋼正火，齒面硬度為大齒輪 240HBS 45 Z =iZ =1.4717=24 （6.1）21 取 Z =25.2 齒輪精度 按 GB/T100951998，選擇 7 級，齒根噴丸強化。 6.1.2 初步設(shè)計齒輪傳動的主要尺寸 按齒面接觸強度設(shè)計 21 31 )(2HEdtt ZuTK （6.2） 確定各參數(shù)的值: (1) 試選 =1.6tK 查課本 圖 10-30 選取區(qū)域系數(shù) Z =2.433 217PH 由課本 圖 10-26 578.0182.0 則 6.8.0. (2) 由課本 公式 10-13 計算應(yīng)力循環(huán)數(shù)2 N =60n j =60701（18300 ） (6.3)1hL10 =1.008 h80 N = =0.6810 h 2 無錫太湖學(xué)院學(xué)士學(xué)位論文 10 (3) 查課本 10-19 圖得：K =0.93 K =0.96203P12 (4) 齒輪的疲勞強度極限 取失效概率為 1%,安全系數(shù) S=1,應(yīng)用 公式 10-12 得:205P = =0.93550=511.5 (6.4)H1SHN1limMa = =0.96450=432 (6.4)2KN2li P 許用接觸應(yīng)力 (6.5)aHH 75.412/)35.1(/)(21 (5) 查課本由 表 10-6 得： =189.8MP 201PEZa 由 表 10-7 得: =15d T=95.510 =95.510 0.1/70 (6.6)51/nP5 =1.310 N.mm4 6.1.3 設(shè)計計算 (1) 小齒輪的分度圓直徑 d t1 (6.7)32.4m5.7418932.1.61032 )(342131 HEdtt ZuTK (2) 計算圓周速度 (6.8) sndt /.00.7.01 (3) 計算齒寬 b 和模數(shù) ntm 計算齒寬 b b= =34.71mm (6.9)td1 計算摸數(shù) m n 初選螺旋角 =14 (6.10)81m9.174cos.3cos1Zdtnt (4) 計算齒寬與高之比 hb 齒高 h=2.25 =2.251.981=4.5mmntm 人力提升機傳動方案的擬定與計算設(shè)計 11 （6.11).75.431hb (5) 計算縱向重合度 =0.318 =1.348 (6.12)1d 14tan738.0tan (6) 計算載荷系數(shù) K 使用系數(shù) =1A 根據(jù) v=0.13m/s,7 級精度 , 查課本由 表 10-8 得210P 動載系數(shù) K =1.07,V 查課本由 表 10-4 得 K 的計算公式:196PH K = +0.2310 b (6.13)H)6.01(8.2.2d3 =1.12+0.18(1+0.6 1) 1+0.2310 10.8=1.40 查課本由 表 10-13 得: K =1.35195F 查課本由 表 10-3 得: K = =1.43PH 故載荷系數(shù): KK K K K =11.071.21.40=1.80 (6.14) (7) 按實際載荷系數(shù)校正所算得的分度圓直徑 d =d = mm (6.15)1tt/3 09.36.18743 (8) 計算模數(shù) nm (6.16)mZ5.27cos09.6cos1 6.1.4 齒根彎曲疲勞強度設(shè)計 由彎曲強度的設(shè)計公式 (6.17)nm)(cos21 23FSadYZKT 確定計算參數(shù) 計算載荷系數(shù)： KK K K K =11.071.21.351.73 (6.18) 根據(jù)縱向重合度 ，從圖 10-28 查的螺旋角影響系數(shù) =0.88348.1 Y 計算當(dāng)量齒數(shù) （6.19)6.1893.07cos331 COSZV (6.20)4.2.514s20332V 無錫太湖學(xué)院學(xué)士學(xué)位論文 12 查取齒形系數(shù)，由表 10-15 查的 Y 2.592 Y 2.211 查取應(yīng)力校正系數(shù)，由表 10-5 查的 Y 1.596 Y 1.774 小齒輪傳遞的轉(zhuǎn)矩 T=13.64KN 初選寬系數(shù) ，按對稱布置，查得 =1dd 初選螺旋角 o14 重合度系數(shù) Y 端面重合度近似為 1.88-3.2（ ） (6.21)21Zcos 1.883.2（1/241/78）cos14 1.655 計算大小齒輪的 并加以比較FSY 安全系數(shù)由表查得 S 1.25 工作壽命一班制，10 年，每年工作 300 天 小齒輪應(yīng)力循環(huán)次數(shù) N160nj 6070183001101.008 hhL 810 大齒輪應(yīng)力循環(huán)次數(shù) N2N1/u1.008 h/1.47=0.68h0 查課本由 表 10-20c 得到彎曲疲勞強度極限 208P 小齒輪 大齒輪aFM51aFMP382 查課本由 表 10-18 得彎曲疲勞壽命系數(shù) :97 K =0.86 K =0.93 1N2N 取彎曲疲勞安全系數(shù) S=1.4 = (6.22)F1 14.307.15860SF = (6.22)2 .2.92N 01347.307561FSY （6.23） 5.4.252FS 人力提升機傳動方案的擬定與計算設(shè)計 13 大齒輪的數(shù)值大.選用. 6.1.5 設(shè)計計算 (1) 計算模數(shù) (6.24)nm)(cos21 23FSadYZKT = 3 2 465.4103.01cs8.07o =0.8104 對比計算結(jié)果，由齒面接觸疲勞強度計算的法面模數(shù) m 大于由齒根彎曲疲勞強度計n 算的法面模數(shù)，按 GB/T1357-1987 圓整為標(biāo)準(zhǔn)模數(shù) ,取 m =2mm 但為了同時滿足接觸疲勞 強度，需要按接觸疲勞強度算得的分度圓直徑 d =33.7mm.于是由:1 取 z =17 (6.25)5.74co36.82z1nms 那么 z =1.4717=25 2 (2) 幾何尺寸計算 計算中心距 a= (6.26)m29.431c257cos)(21 oszn 將中心距圓整為 44mm 按圓整后的中心距修正螺旋角 (6.27)o02.149.32)57(arcos2)(cosar1 Z 因 值改變不多,故參數(shù) , , 等不必修正.kh 計算大.小齒輪的分度圓直徑 35.04mm (6.28)o02.14cs7od21nmZ d = mm (6.29)2 53. 計算齒輪寬度 B= 圓整的 402B351 無錫太湖學(xué)院學(xué)士學(xué)位論文 14 6.2 從動輪上齒輪傳動的設(shè)計和計算 6.2.1 齒輪材料，熱處理及精度 考慮此減速器的功率及現(xiàn)場安裝的限制，故大小齒輪都選用硬齒面漸開線斜齒輪 1 齒輪材料及熱處理 （1）材料：高速級小齒輪選用 鋼調(diào)質(zhì)，齒面硬度為小齒輪 280HBS 取小齒齒數(shù)45 =25Z 高速級大齒輪選用 鋼正火，齒面硬度為大齒輪 240HBS Z =iZ =3.30225=82.55 取 Z =83. （6.30）21 2 （2）齒輪精度 按 GB/T100951998，選擇 7 級，齒根噴丸強化。 6.2.2 初步設(shè)計齒輪傳動的主要尺寸 按齒面接觸強度設(shè)計 2131 )(2HEdtt ZuTK 確定各參數(shù)的值: （1）試選 =1.6tK 查課本 圖 10-30 選取區(qū)域系數(shù) Z =2.433 215PH 由課本 圖 10-26 478.0182.0 則 6.8.07. （2）由課本 公式 10-13 計算應(yīng)力循環(huán)數(shù)2 N =60n j =6063.31（18300 ）1hL10 =0.68 h80 N =0.2010 h2 （3）查課本 10-19 圖得：K =0.93 K =0.96203P12 （4）齒輪的疲勞強度極限 取失效概率為 1%,安全系數(shù) S=1,應(yīng)用 公式 10-12 得:205P = =0.93550=511.5 H1SHN1limMPa = =0.96450=432 2KN2li 許用接觸應(yīng)力 PaHH 75.412/)35.1(/)(21 人力提升機傳動方案的擬定與計算設(shè)計 15 （5）查課本由 表 10-6 得： =189.8MP 198PEZa 由 表 10-7 得: =0.25201d T=95.510 =95.510 0.095/47.651/nP5 =1.910 N.mm4 6.2.3 設(shè)計計算 （1）小齒輪的分度圓直徑 d t1m635.74189320.192)(2423 HEdtt ZuTK （2）計算圓周速度 smndt /09.16034.3160 （3）計算齒寬 b 和模數(shù) nt 計算齒寬 b b= =36mmtd1 計算摸數(shù) m n 初選螺旋角 =14 m397.1254cos36cos1Zdtnt （4）計算齒寬與高之比 hb 齒高 h=2.25 =2.251.397=3.14mmntm 1.46.3hb （5）計算縱向重合度 =0.318 =1.9031d 1tan258.0tan （6）計算載荷系數(shù) K 使用系數(shù) =1A 根據(jù) v=0.09m/s,7 級精度, 查課本由 表 10-8 得194P 動載系數(shù) K =1.07,V 查課本由 表 10-4 得 K 的計算公式:194PH 無錫太湖學(xué)院學(xué)士學(xué)位論文 16 K = +0.2310 bH)6.01(8.2.2d3 =1.12+0.18(1+0.6 1) 1+0.2310 10.8=1.423 查課本由 表 10-13 得: K =1.35198PF 查課本由 表 10-3 得: K = =1.25H 故載荷系數(shù): K K K K K =11.071.21.42=1.82 （7）按實際載荷系數(shù)校正所算得的分度圓直徑 d =d = mm1tt/3 58.73.6123 （8）計算模數(shù) nmmZ4.25cos8.7cos1 6.2.4 齒根彎曲疲勞強度設(shè)計 由彎曲強度的設(shè)計公式 nm)(cos21 23FSadYZKT 確定公式內(nèi)各計算數(shù)值 計算載荷系數(shù)： K K K K K =11.071.21.351.73 根據(jù)縱向重合度 ，從圖 10-28 查的螺旋角影響系數(shù) =0.88348.1 Y 計算當(dāng)量齒數(shù) 5.27913.04cos25331 COSZV .8s0332V 查取齒形系數(shù)，由表 10-15 查的 Y 2.592 Y 2.211 查取應(yīng)力校正系數(shù)，由表 10-5 查的 Y 1.596 Y 1.774 小齒輪傳遞的轉(zhuǎn)矩 T=18.87KN 初選寬系數(shù) ，按對稱布置，查得 =1dd 初選螺旋角 o14 人力提升機傳動方案的擬定與計算設(shè)計 17 重合度系Lathes Lathes are machine tools designed primarily to do turning, facing and boring, Very little turning is done on other types of machine tools, and none can do it with equal facility. Because lathes also can do drilling and reaming, their versatility permits several operations to be done with a single setup of the work piece. Consequently, more lathes of various types are used in manufacturing than any other machine tool. The essential components of a lathe are the bed, headstock assembly, tailstock assembly, and the leads crew and feed rod. The bed is the backbone of a lathe. It usually is made of well normalized or aged gray or nodular cast iron and provides s heavy, rigid frame on which all the other basic components are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted V-shape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets, They are precision-machined to assure accuracy of alignment. On most modern lathes the way are surface-hardened to resist wear and abrasion, but precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed.The headstock is mounted in a foxed position on the inner ways, usually at the left end of the bed. It provides a powered means of rotating the word at various speeds . Essentially, it consists of a hollow spindle, mounted in accurate bearings, and a set of transmission gears-similar to a truck transmissionthrough which the spindle can be rotated at a number of speeds. Most lathes provide from 8 to 18 speeds, usually in a geometric ratio, and on modern lathes all the speeds can be obtained merely by moving from two to four levers. An increasing trend is to provide a continuously variable speed range through electrical or mechanical drives.Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually tapered roller or ball types. The spindle has a hole extending through its length, through which long bar stock can be fed. The size of maximum size of bar stock that can be machined when the material must be fed through spindle.The assembly consists, essentially, of three parts. A lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired location, An upper casting fits on the lower one and can be moved transversely upon it, on some type of keyed ways, to permit aligning the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 51 to 76mm(2to 3 inches) in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a hand wheel and screw.The size of a lathe is designated by two dimensions. The first is known as the swing. This is the maximum diameter of work that can be rotated on a lathe. It is approximately twice the distance between the line connecting the lathe centers and the nearest point on the ways, The second size dimension is the maximum distance between centers. The swing thus indicates the maximum work piece diameter that can be turned in the lathe, while the distance between centers indicates the maximum length of work piece that can be mounted between centers.Engine lathes are the type most frequently used in manufacturing. They are heavy-duty machine tools with all the components described previously and have power drive for all tool movements except on the compound rest. They commonly range in size from 305 to 610 mm(12 to 24 inches)swing and from 610 to 1219 mm(24 to 48 inches) center distances, but swings up to 1270 mm(50 inches) and center distances up to 3658mm(12 feet) are not uncommon. Most have chip pans and a built-in coolant circulating system. Smaller engine lathes-with swings usually not over 330 mm (13 inches ) also are available in bench type, designed for the bed to be mounted on a bench on a bench or cabinet. Although engine lathes are versatile and very useful, because of the time required for changing and setting tools and for making measurements on the work piece, thy are not suitable for quantity production. Often the actual chip-production tine is less than 30% of the total cycle time. In addition, a skilled machinist is required for all the operations, and such persons are costly and often in short supply. However, much of the operators time is consumed by simple, repetitious adjustments and in watching chips being made. Consequently, to reduce or eliminate the amount of skilled labor that is required, turret lathes, screw machines, and other types of semiautomatic and automatic lathes have been highly developed and are widely used in manufacturing.One of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC). Prior to the advent of NC, all machine tools ere manually operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator. Numerical control represents the first major step away from human control of machine tools. Numerical control means the control of machine tools and other manufacturing systems through the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool. For a machine tool to be numerically controlled, it must be interfaced with a device for accepting and decoding the programmed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operators, and it has done so. Numerical control machines are more accurate than manually operated machines, they can produce parts more uniformly, they are faster, and the long-run tooling costs are lower. The development of NC led to the development of several other innovations in manufacturing technology:Electrical discharge machining,Laser cutting,Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide of parts, each involving an assortment of widely varied and complex machining processes. Numerical control has allowed manufacturers to undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tolls and processes.Like so many advanced technologies, NC was born in the laboratories of the Massachusetts Institute of Technology. The concept of NC was developed in the early 1950s with funding provided by the U.S. Air Force. In its earliest stages, NC machines were able to made straight cuts efficiently and effectively. However, curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter the straight lines making up the steps, the smoother is the curve, Each line segment in the steps had to be calculated. This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language. This is a special programming language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the fur their development from those used today. The machines had hardwired logic circuits. The instructional programs were written on punched paper, which was later to be replaced by magnetic plastic tape. A tape reader was used to interpret the instructions written on the tape for the machine. Together, all of this represented a giant step forward in the control of machine tools. However, there were a number of problems with NC at this point in its development. A major problem was the fragility of the punched paper tape medium. It was common for the paper tape containing the programmed instructions to break or tear during a machining process. This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to be rerun through the reader. If it was necessary to produce 100 copies of a given part, it was also necessary to run the paper tape through the reader 100 separate tines. Fragile paper tapes simply could not withstand the rigors of a shop floor environment and this kind of repeated use.This led to the development of a special magnetic plastic tape. Whereas the paper carried the programmed instructions as a series of holes punched in the tape, the plastic tape carried the instructions as a series of magnetic dots. The plastic tape was much stronger than the paper tape, which solved the problem of frequent tearing and breakage. However, it still left two other problems.The most important of these was that it was difficult or impossible to change the instructions entered on the tape. To made even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape through the reader as many times as there were parts to be produced. Fortunately, computer technology became a reality and soon solved the problems of NC associated with punched paper and plastic tape.The development of a concept known as direct numerical control (DNC) solved the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions. In direct numerical control, machine tools are tied, via a data transmission link, to a host computer. Programs for operating the machine tools are stored in the host computer and fed to the machine tool an needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However, it is subject to the same limitations as all technologies that depend on a host computer. When the host computer goes down, the machine tools also experience downtime. This problem led to the development of computer numerical control. The engine lathe, one of the oldest metal removal machines, has a number of useful and highly desirable attributes. Today these lathes are used primarily in small shops where smaller quantities rather than large production runs are encountered.The engine lathe has been replaced in todays production shops by a wide variety of automatic lathes such as automatic of single-point tooling for maximum metal removal, and the use of form tools for finish on a par with the fastest processing equipment on the scene today.Tolerances for the engine lathe depend primarily on the skill of the operator. The design engineer must be careful in using tolerances of an experimental part that has been produced on the engine lathe by a skilled operator. In redesigning an experimental part for production, economical tolerances should be used.Turret Lathes Production machining equipment must be evaluated now, more than ever before, this criterion for establishing the production qualification of a specific method, the turret lathe merits a high rating. In designing for low quantities such as 100 or 200 parts, it is most economical to use the turret lathe. In achieving the optimum tolerances possible on the turrets lathe, the designer should strive for a minimum of operations.Automatic Screw Machines Generally, automatic screw machines fall into several categories; single-spindle automatics, multiple-spindle automatics and automatic chucking machines. Originally designed for rapid, automatic production of screws and similar threaded parts, the automatic screw machine has long since exceeded the confines of this narrow field, and today plays a vital role in the mass production of a variety of precision parts. Quantities play an important part in the economy of the parts machined on the automatic screw machine. Quantities less than on the automatic screw machine. The cost of the parts machined can be reduced if the minimum economical lot size is calculated and the proper machine is selected for these quantities.Automatic Tracer Lathes Since surface roughness depends greatly on material turned, tooling , and feeds and speeds employed, minimum tolerances that can be held on automatic tracer lathes are not necessarily the most economical tolerances.In some cases, tolerances of 0.05mm are held in continuous production using but one cut . groove width can be held to 0.125mm on some parts. Bores and single-point finishes can be held to 0.0125mm. On high-production runs where maximum output is desirable, a minimum tolerance of 0.125mm is economical on both diameter and length of turn.From the micro perspective, CNC machine tools than traditional machines have the following prominent superiority, and these advantages are from the NC system includes computer power.can be processed by conventional machining is not the curve, surface and other complex partsBecause computers are superb computing power can be accurately calculated instantaneous each coordinate axis movement exercise should be instantaneous, it can compound into complex curves and surfaces.Automated processing can be achieved, but also flexible automation to increase machine efficiency than traditional 3 to 7 times.Because computers are memory and storage capacity, can be imported and stored procedures remember down, and then click procedural requirements to implement the order automatically to achieve automation. CNC machine tool as a replacement procedures, we can achieve another work piece machining automation, so that single pieces and small batch production can be automated, it has been called flexible automation. High precision machining parts, the size dispersion of small, easy to assemble, no longer needed repair.Processes can be realized more focused, in part to reduce the frequent removal machine.Have automatic alarm, automatic control, automatic compensation, and other self-regulatory functions, thus achieving long unattended processing.Derived from the benefits of more than five.Such as: reducing the labor intensity of the workers, save the labor force (one can look after more than one machine), a decrease of tooling, shorten Trial Production of a new product cycle and the production cycle, the market demand for quick response, and so on.These advantages are our predecessors did not expect, is a very major breakthrough. In addition, CNC machine tools or the FMC (Flexible Manufacturing Cell), FMS (flexible manufacturing system) and CIMS (Computer Integrated Manufacturing System), and other enterprises, the basis of information transformation. NC manufacturing automation technology has become the core technology and basic technology.The macro view of the necessity From a macro perspective, the military industrial developed countries, the machinery industry, in the late 1970s, early 1980s, has begun a large-scale application of CNC machine tools. Its essence is the use of information technology on the traditional industries (including the military, the Machinery Industry) for technological transformation. In addition to the manufacturing process used in CNC machine tools, FMC, FMS, but also included in the product development in the implementation of CAD, CAE, CAM, virtual manufacturing and production management in the implementation of the MIS (Management Information System), CIMS, and so on. And the products that they produce an increase in information technology, including artificial intelligence and other content. As the use of information technology to foreign forces, the depth of Machinery Industry (referred to as information technology), and ultimately makes their products in the international military and civilian products on the market competitiveness of much stronger. And we in the information technology to transform traditional industries than about 20 years behind developed countries. Such as possession of machine tools in China, the proportion of CNC machine tools (CNC rate) in 1995 to only 1.9 percent, while Japan in 1994 reached 20.8 percent, every year a large number of imports of mechanical and electrical products. This also explains the macro CNC transformation of the need.Third, CNC machine tools and production lines of the transformation of the market CNC transformation of the market My current machine total more than 380 million units, of which only the total number of CNC machine tool 113,400 Taiwan, or that Chinas CNC rate of less than 3 percent. Over the past 10 years, Chinas annual output of about 0.6 CNC machine tools to 0.8 million units, an annual output value of about 1.8 billion yuan. CNC machine tools annual rate of 6 per cent. Chinas machine to ol easements over age 10 account for more than 60% below the 10 machines, automatic / semi-automatic machine less than 20 per cent, FMC / FMS, such as a handful more automated production line (the United States and Japan automatic and semi-automatic machine, 60 percent above). This shows that we the majority of manufacturing industries and enterprises of the production, processing equipment is the great majority of traditional machine tools, and more than half of military age is over 10 years old machine. Processing equipment used by the prevalence of poor quality products, less variety, low-grade, high cost, supply a long period, in view of the international and domestic markets, lack of competitiveness, and a direct impact on a companys products, markets, efficiency and impact The survival and development of enterprises. Therefore, we must vigorously raise the rate of CNC machine tools. Import equipment and production lines of the transformation of NC market Since Chinas reform and opening up, many foreign enterprises from the introduction of technology, equipment and production lines for technological transformation. According to incomplete statistics, from 1979 to 1988 10, the introduction of technological transformation projects are 18,446, about 16.58 billion US dollars. These projects, the majority of projects in Chinas economic construction play a due role. Some, however, the introduction of projects due to various reasons, not equipment or normal operation of the production line, and even paralyzed, and the effectiveness of enterprises affected by serious enterprise is in trouble. Some of the equipment, production lines introduced from abroad, the digestion and absorption of some bad, spare parts incomplete, improper maintenance, poor operating results; only pay attention to the introduction of some imported the equipment, apparatus, production lines, ignore software, technology, and management, resulting in items integrity, and potential equipment can not play, but some can not even start running, did not play due role, but some production lines to sell the products very well, but not because of equipment failure production standards; because some high energy consumption, low pass rate products incur losses, but some have introduced a longer time, and the need for technological upgrading. Some of the causes of the equipment did not create wealth, but consumption of wealth. These can not use the equipment, production lines is a burden, but also a number of significant assets in stock, wealth is repaired. As long as identifying the main technical difficulties, and solve key technical problems, we can minimize the investment and make the most of their a