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支撐跨度 L1應略大于 LU,取為 L1=267mm。臨界壓 縮負荷為 m a x02121 / FLEI KfF cr ?? ? () 式中 E 材料的彈性模量, 211 / mNE ?? ; I—— 絲杠最小截面慣性矩4712402464/10)(64/)(64/mDddI w?????????????? L0—— 最大受壓長度,按照結(jié)構(gòu)設計取 L0=284mm; K1—— 安全系數(shù),一般取 K1=1/3; maxF —— 最大軸向工作載荷, NF 107max ? ; 1f —— 絲杠支撐方式系數(shù),查表得 21?f ,則 m a x6627112 )102843/( FNF cr ??? ??????????? () 可見 crF 遠大于 maxF ,滿足要求 壓振動和扭轉(zhuǎn)振動的固有頻率驗算 已知:軸承的接觸剛度 mNkB ?/1080? ,絲杠螺母的接觸剛度 mNKC ?/1692? ,絲杠的最小拉壓剛度mNLAEK mNLAEK ss ? ?/53m i n?????? ?????? ??() 陜西理工學院畢業(yè)設計 第 14 頁 共 21 頁 當導軌運動到兩極位置時,有最大和最小拉壓剛度,其中, L分別為 284mm和 100mm。軸向拉壓總剛度為: mNK KKKKE sCBe ?/128 ? ??????? () 絲杠拉壓振動的固有頻率 m i n/7165/??????? () 由計算可知,絲杠拉壓振動的固有頻率遠遠大于 30r/min,所以能滿足要求 。 傳動精度計算 絲杠的拉壓剛度 LEdKS 42?? () 由以上的各條件可知最小機械傳動剛度為 mNKKKKBcs?/1211080/11692/1/1/1/11m inm in0??????? () 最大機械傳動剛度 陜西理工學院畢業(yè)設計 第 15 頁 共 21 頁 mNKKKKBcsm a nm a n?/4551080/11692/11652/11/1/1/110??????? () 因此得到由于機械傳動裝置所引起的定位誤差為 mKKF qk ?? )4551_1211(20)1_1( m a x0m i n0 ???? () 其中, F0為空載時導軌的靜摩擦力。 ( 1) 選擇蝸桿傳動類型 根據(jù) GB/T 100851988的推存,采用漸開線蝸桿( ZI)。 因而蝸輪用鑄錫磷青銅 ZCuSn10P1,金屬模鑄造。 (3) 按齒面接觸疲勞強度進行設計 根據(jù)閉式蝸桿傳動的設計準則,先按齒面接觸疲勞強度進行設計,再校核齒根彎曲疲勞強度。 由 機械設計手冊 取使用系數(shù) AK = 由轉(zhuǎn)速不高,沖擊不大,可取動載荷系數(shù) VK =。H? = 268 aMP = () 計算中心距 a ≥ 23 1 6 0 3 .11 .3 8 9 3 8 1 0 01 8 8 .6????? ????mm=95mm () 取中心距 a=97mm,完全滿足要求, 取模數(shù) m=2,蝸桿分度圓直徑 d1=56mm。 蝸桿與蝸輪 主要幾何參數(shù) ① 蝸桿 直徑系數(shù) q=d1/m=28 齒頂圓直徑 da1=d1+2 *ah m=56+2 1 2mm=60mm 齒根圓直徑 df1=d1 1fh = d12 m ( *ah +*c )=562 2 (1+)mm= 導程角 γ = 011 18’ 31’’ 蝸桿軸向齒厚 Sa=? m= 2mm= ② 蝸輪 蝸輪齒數(shù) 2Z =69 分度圓直徑 2d =m 2Z =2 69mm=138mm 齒頂圓直徑 da2= 2d +2ha2=138+2 2 =143mm 齒根圓直徑 df2= 2d 2fh =1382 2 1mm=134mm 校核齒根彎曲疲勞強度 ? ?22121 .5 3F F a FKT YYd d m ????? () 當量齒數(shù) ? ?22 33052c osc os 1rZZ ??? = () 由 2x = +, 2rZ =,查 機械設計手冊可 得齒形系數(shù) 2FaY = 螺旋角系數(shù) Y? =10140?=1 0= () 許用彎曲應力 F? =? ?39。F? =56 aMP 陜西理工學院畢業(yè)設計 第 17 頁 共 21 頁 壽命系數(shù) 698101. 66 10FNK ? ?= () ? ?F? = FNK ? ?39。 、裝配圖的繪制 對于上述兩大傳動的設計,從 XY絲桿傳動來實現(xiàn)工作臺左右移動,同時蝸輪蝸桿的設計使得工作圓盤呈現(xiàn)圓周的運動,使直線運動變?yōu)閳A周的運動,所以最終設計出具有橫向和縱向的調(diào)節(jié)底座,同時具有旋轉(zhuǎn)功能,如下圖 : 圖 顯微鏡基座設計圖 、本章小結(jié) 本章通過對傳動機構(gòu)的整體的選材和整體的設計,通過查閱圖書等資料進行各項的驗證。該軟件常用于機械設計,上手使用比較容易。故此選擇該軟件進行設計。進而完善自己的圖紙以及論文。它包含了機械設計、機械制圖、工程材料、公差、材料力學、理論力學、機械原理等課程。它在我們四年的大學生活學習中占有很重要的地位,也為日后走上社會,走進工作崗位后工更好的工作及生活打下了良好的基礎。所以,設計不僅僅是一項電腦前和辦公室里的工作,它需要走進社會,走入市場,進行設計前的調(diào)研,深刻了解到所設計內(nèi)容的市場情況和人們的需求,才能在此基礎上進行設計工作,進而才能進行產(chǎn)品的優(yōu)化設計。 陜西理工學院畢業(yè)設計 第 20 頁 共 21 頁 致謝 感謝我的導師陳純老師他們嚴謹細致、一絲不茍的作風一直是我工作、學習中的榜樣;他們循循善誘的教導和不拘一格的思路給予我無盡的啟迪。四年了,仿佛就在昨天。只是今后大家就難得再聚在一起吃每年元旦的那頓飯了吧,沒關系,各奔前程,大家珍重。 感謝我的爸爸媽媽,焉得諼草,言樹之背,養(yǎng)育之恩,無以回報,你們永遠健康快樂是我最大的心愿。 SEMs, scanning electron microscopes。REZ‐ WILLARD,Z. RADI,S. OFFERN,I. BURKART,. KUKLA,U. WOLLENBERG. Argon broad ion beam tomography in a cryogenic scanning electron microscope: a novel tool for the investigation of representative microstructures in sedimentary rocks containing pore fluid[J]. Journal of Microscopy,2020,2493:. [21]E Franceschi,G Luciano,F Carosi,L Cornara,C Montanari. Thermal and microscope analysis as a tool in the characterisation of ancient papyri[J]. Thermochimica Acta,2020,4181:. 陜西理工學院畢業(yè)設計 About Microscope Microscope is formed by the bination of a lens or lenses of an optical instrument, is a sign of human beings into the atomic age. Mainly used to magnify tiny objects bee instruments of the human eye can see. Microscope, optical microscope and electron microscope, optical microscope was invented in the 1590 by the Dutch Jason and his son. The optical microscope can magnify the object 1600 times now, distinguish the minimum limit of microns, domestic microscope mechanical tube length is 160 mm. The development of microscope, microbiology has a great contribution to human Leeuwenhoek, Dutch. Microscope is one of the greatest inventions in this period. Before it invented, human ideas about the world around us to the naked eye, or by holding a lens help the naked eye can see. Microscope to a whole new world in the human vision. People first saw hundreds of tiny plants and animals, and the new, and from the body to the internal structure of plant fiber and other things. Microscope can also help scientists have discovered a new species, help doctors to treat disease. The tool microscope is a member of the family under the microscope. Tool microscope is also called the tools with a microscope, is a type of tool manufacture high precision of two dimensional coordinates measuring instrument used. It with ordinary microscope imaging principle, and then add some other tools to achieve the purpose of measuring specific principle is: it is the use of optical imaging principle, the workpiece by the projection of the objective to the eyepiece, namely through the light will be enlarged into a virtual image artifacts, recycle loading content with the eyepiece cable (eyepiece reticle) and other auxiliary, as dimension, Angle and shape measurement, such as nonmetallic luster can be used as a test of the workpiece surface. This instrument on the columns is equipped with a microscope, magnification from between 10 and 100 times of several kinds of ratio, tool microscope measurement system light source (lamp) after electricity, light, in tu