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1、<p><b> 目 錄</b></p><p><b> 前言1</b></p><p><b> 1、課題要求2</b></p><p> 1.1主要內(nèi)容與要求2</p><p> 1.2主要技術(shù)指標(biāo)2</p><p>&
2、lt;b> 2、方案的擬定2</b></p><p> 3、零部件及結(jié)構(gòu)的初步設(shè)計3</p><p> 3.1輥子的設(shè)計3</p><p> 3.1.1材料選擇3</p><p> 3.1.2尺寸設(shè)計3</p><p> 3.2電動機及V帶的選擇5</p><
3、;p> 3.2.1粉碎機功率的計算5</p><p> 3.2.2電動機的選擇5</p><p> 3.2.3 V帶的選擇6</p><p> 3.3軸的設(shè)計與校核8</p><p> 3.3.1軸的材料的選擇8</p><p> 3.3.2各段軸的軸徑、軸長及軸承的確定8</p&g
4、t;<p> 3.3.3軸的校核10</p><p> 3.3.4滾動軸承的校核13</p><p> 3.3.5鍵的設(shè)計與校核14</p><p> 4.1機架的設(shè)計15</p><p> 4.2罩子的設(shè)計15</p><p><b> 4.3其他16</b>
5、;</p><p><b> 5、結(jié)論16</b></p><p><b> 致謝17</b></p><p><b> 參考文獻18</b></p><p><b> 附錄119</b></p><p><b
6、> 附錄220</b></p><p><b> 前言</b></p><p> 機械加工行業(yè)在我國有著舉足輕重的地位,它是國家的國民經(jīng)濟命脈。作為整個工業(yè)的基礎(chǔ)和重要組成部分的機械制造業(yè),任務(wù)就是為國民經(jīng)濟的各個行業(yè)提供先進的機械裝備和零件。它的規(guī)模和水平是反映國家的經(jīng)濟實力和科學(xué)技術(shù)水平的重要標(biāo)志,因此非常值得重視和研究。</p&g
7、t;<p> 在日常工作與生活中,由于需要經(jīng)常會對一些物料加以粉碎,從而達到使用的要求。單靠人力來粉碎物料在大多數(shù)情況下已經(jīng)不能滿足生產(chǎn)與生活的需求了,所以用機器來代替手工勞動顯得尤為重要。輥子粉碎機是一種結(jié)構(gòu)簡單、成本較低且節(jié)能的粉碎設(shè)備,它的主要結(jié)構(gòu)有兩個相向轉(zhuǎn)動的磨輥、加料器、加料漏斗、支架以及電動機。粉碎機的兩個磨輥間距可調(diào),故而可以控制出料粒度為生產(chǎn)帶來方便。輥子粉碎機可以應(yīng)用與制粉工業(yè)、礦業(yè)、建筑業(yè)及飼料生產(chǎn)
8、等方面,在我國的經(jīng)濟建設(shè)中發(fā)揮了不小的作用。</p><p> 主要設(shè)計內(nèi)容包括輥子尺寸的選擇,軸的設(shè)計與校核,軸承的選擇與計算,V帶傳動的設(shè)計與計算,機架的設(shè)計與計算以及其他零部件的選擇確定。設(shè)計過程綜合機械設(shè)計基礎(chǔ)的大部分內(nèi)容,通過設(shè)計進一步掌握機械傳動部件和簡單機械裝置的設(shè)計,具備運用標(biāo)準(zhǔn)、規(guī)范、手冊、圖冊和查閱有關(guān)技術(shù)資料的能力,提高機械設(shè)計能力。</p><p><b&g
9、t; 1、課題要求</b></p><p> 1.1主要內(nèi)容與要求</p><p><b> 1、方案的擬定</b></p><p> 2、機械傳動的運動和動力參數(shù)計算</p><p><b> 3、材料選擇</b></p><p> 4、零、部件及結(jié)
10、構(gòu)的初步設(shè)計</p><p> 5、傳動件的校核計算</p><p> 6、 零、部件及結(jié)構(gòu)設(shè)計的最終確定</p><p><b> 7、編寫設(shè)計說明書</b></p><p> 8、繪制零件圖及裝配圖</p><p><b> 1.2主要技術(shù)指標(biāo)</b></
11、p><p><b> 1、出料粒度可調(diào)</b></p><p> 2、生產(chǎn)能力5-10噸/小時</p><p><b> 2、方案的擬定</b></p><p> 輥式粉碎機利用水平放置的旋轉(zhuǎn)軋輥壓碎或軋碎物料。按照軋輥的數(shù)目可以分為單輥式、雙輥式和多輥式(一般是四輥)等:(1)單輥式粉碎機,用
12、于粉碎石灰石等物料,物料塊在輥子與帶齒之間被軋碎;(2)雙輥式粉碎機,用于粉碎中等硬度物料,物料塊在兩輥子之間被粉碎;(3)多輥式粉碎機與雙輥式的結(jié)構(gòu)相似,只是有多個輥子,以增大粉碎比并減少裝機占地面積。輥子按照軋輥表面特征,分為光面、槽面和齒面三種:(1)光面輥子主要以擠壓方式粉碎物料,適于粉碎中等硬度或堅硬的石料,兩個輥子轉(zhuǎn)速也可不一樣,使物料受到磨削作用,宜于細(xì)碎黏土及塑性物料,成品粒度小而均勻。(2)槽面輥子除有擠壓作用外,還帶
13、剪切力,適于粉碎強度不大的脆性或粘濕性物料,成品粒度比較均勻。(3)齒面輥子除有擠壓作用外,還有劈裂力,適于粉碎具有片狀紋理的軟質(zhì)和低硬度脆性物料,成品粒度也較均勻。本設(shè)計以粉碎煤為例,采用光面雙輥式粉碎機。</p><p> 雙輥式粉碎機的粉碎機構(gòu)是一對圓柱形輥子,他們相互平行安裝在機架上,前輥和后輥作相向旋轉(zhuǎn)。物料加入喂料箱內(nèi),落在轉(zhuǎn)輥的上面,在棍子表面摩擦力作用下被拉進兩輥之間,受到輥子的擠壓而粉碎。粉碎
14、后的物料被轉(zhuǎn)輥推出向下卸落。輥子安裝在焊接的機架上,中間做成空心以節(jié)省材料,兩端各有一個焊接在鋼板上的軸鑲嵌其中。前輥安裝在滾動軸承內(nèi),軸承座固定安裝在機架上。后輥的軸承座則安裝在機架的導(dǎo)軌中,可在導(dǎo)軌上前后移動。導(dǎo)軌底座上裝有螺釘及彈簧,根據(jù)螺釘旋入長度的不同即可調(diào)節(jié)兩輥子間距。前輥和后輥都通過傳動軸及皮帶輪用電動機分別帶動。</p><p> 3、零部件及結(jié)構(gòu)的初步設(shè)計</p><p&g
15、t;<b> 3.1輥子的設(shè)計</b></p><p><b> 3.1.1材料選擇</b></p><p> 粉碎機工作的時候,輥子與物料接觸并擠壓物料從而達到粉碎的目的,為了保證粉碎級能有效的工作以及有足夠的使用壽命,輥子的材料要求有足夠的強度、耐磨性。</p><p> 選則輥子的材料為45號鋼,表面淬火處理
16、,硬度為。。</p><p><b> 3.1.2尺寸設(shè)計</b></p><p> 輥子粉碎機的規(guī)格用輥子直徑和長度來表示。因輥子表面磨損不均勻,因此輥子長度不應(yīng)大于輥子直徑,一般取</p><p> = 3-1</p><p> 取輥子直徑=300m
17、m ,輥子長L=200mm 。</p><p> 查《非標(biāo)準(zhǔn)機械設(shè)備設(shè)計手冊》,取輥子直徑與喂料粒度之間的關(guān)系為:</p><p> =30 3-2</p><p><b> 喂料粒度</b></p><p> 查資料可知無煙煤的密度約為:
18、 </p><p> 查《非標(biāo)準(zhǔn)機械設(shè)備設(shè)計手冊》,輥子的極限轉(zhuǎn)速為:</p><p> n=(r/min) 3-3</p><p> 式中---物料與棍子表面的摩擦系數(shù)(干硬物料在金屬表面上的摩擦系數(shù)=0.3);</p><p><b> ---物料密度,;</b&g
19、t;</p><p> ---喂入粉碎機的物料粒徑,; </p><p> D---輥子直徑,。</p><p> 由已知條件可求得輥子極限轉(zhuǎn)速為:</p><p><b> =183 </b></p><p> 實際應(yīng)用中,為了減小粉碎機的振動和輥子表面的磨損,可使輥子轉(zhuǎn)速稍低于極限轉(zhuǎn)
20、速,取n=180則</p><p><b> 輥子的圓周速度為:</b></p><p> ?。ǎ?3-4</p><p><b> =m/s2.8</b></p><p> 查《非標(biāo)準(zhǔn)機械設(shè)備設(shè)計手冊》,輥子粉碎機的生產(chǎn)能力為
21、</p><p><b> 3-5</b></p><p> 式中---生產(chǎn)能力,;</p><p> ---輥子圓周速度,;</p><p> ---物料粉碎后的堆積密度,;</p><p> ---輥子間距,; </p><p><b> ---輥
22、子長度,。</b></p><p> 從而可得輥子間距為:</p><p><b> 3-6</b></p><p><b> = =2.3</b></p><p><b> =4.5</b></p><p> 為了節(jié)省材料可以把輥
23、子做成中空的圓筒狀,同時為了保證輥子能正常工作筒壁不宜過薄,取輥子內(nèi)徑。在輥子兩端面各加工一個深度為10mm,內(nèi)徑為的圓槽,將兩個直徑為厚度為10mm的圓形鋼板分別鑲嵌在兩個圓槽內(nèi),在鋼板中間鉆一個直徑為74mm的通孔,將軸焊接在鋼板上,如圖3-1所示。</p><p> 3.2電動機及V帶的選擇</p><p> 3.2.1粉碎機功率的計算</p><p>
24、 粉碎機的功率可用經(jīng)驗公式計算。粉碎中硬物料時,粉碎機所需功率為:</p><p> (kW) 3-7</p><p> 式中,和分別為喂料粒度和卸料粒度。</p><p> 取=2.3得:=2.76</p><p> 取=4.5得:=1.48</p><p&
25、gt; 3.2.2電動機的選擇</p><p> (一)電動機類型和結(jié)構(gòu)的選擇</p><p> 因為本傳動的工作狀況是:載荷平穩(wěn)、單向旋轉(zhuǎn)。所以選用常用的封閉式Y(jié)(IP44)系列的電動機。 </p><p> ?。ǘ╇妱訖C容量的選擇</p><p><b> 1.工作機所需功率</b></p>
26、<p> 為了使粉碎機在輥子可調(diào)間距范圍內(nèi)都可正常工作,以來計算電動機的功率。所以工作機所需功率為= =1.23</p><p><b> 2.電動機輸出功率</b></p><p> 查《機械設(shè)計手冊》取V帶與滾動軸承的傳動效率分別為 =0.94 =0.99</p><p><b> 3-8</b>&
27、lt;/p><p><b> ==1.32。</b></p><p> 3.電動機型號的選擇</p><p> 查《機械設(shè)計手冊》選電動機型號為Y132S-8,額定功率2.2,滿載轉(zhuǎn)速</p><p><b> ,基本符合要求。</b></p><p> 3.2.3 V
28、帶的選擇</p><p> V帶的橫截面積為等腰梯形,工作時其兩側(cè)面與輪槽的側(cè)面相接處,而V帶與輪槽槽底并不接觸。由于輪槽的楔形效應(yīng),初拉力相同時,V帶傳動較平帶傳動能產(chǎn)生更大的摩擦力,具有較大的牽引能力。</p><p><b> ?。?)求計算功率</b></p><p> 查《機械設(shè)計手冊》表13-8得工作情況系數(shù)為,故</p&
29、gt;<p><b> 3-9</b></p><p> ?。?)求大、小帶輪基準(zhǔn)直徑、</p><p> 查《機械設(shè)計基礎(chǔ)》選小帶輪型號為B,基準(zhǔn)直徑125,轉(zhuǎn)速800,額定功率1.44。</p><p> 由《機械設(shè)計基礎(chǔ)》式13-9得</p><p><b> 3-10</b&
30、gt;</p><p> 式中、分別為大小帶輪的轉(zhuǎn)速,為V帶傳動的滑動率()。</p><p> 大帶輪的轉(zhuǎn)速與輥子的轉(zhuǎn)速相同n=180,小帶輪轉(zhuǎn)速與電動機轉(zhuǎn)速相同710,取 則,查《機械設(shè)計課程設(shè)計》取500mm,帶速為:。</p><p> 查《機械設(shè)計課程設(shè)計》表4-2,選擇大帶輪型號為B,基準(zhǔn)直徑500,孔徑60mm,轂長65mm。</p>
31、<p> ?。?)求V帶基準(zhǔn)長度和中心距</p><p><b> 初步選取中心距為,</b></p><p> 取,查《機械設(shè)計基礎(chǔ)》可知帶長為:</p><p><b> 3-11</b></p><p><b> =</b></p>&
32、lt;p> 查《機械設(shè)計基礎(chǔ)》表13-2,對B型帶選用。再由《機械設(shè)計基礎(chǔ)》式13-16計算實際中心距:</p><p><b> 3-12</b></p><p> ?。?)驗算小帶輪包角</p><p> 由《機械設(shè)計基礎(chǔ)》式13-1得</p><p><b> 3-13</b>&
33、lt;/p><p><b> 故合適。</b></p><p><b> (5)求V帶根數(shù)</b></p><p> 由《機械設(shè)計基礎(chǔ)》式13-15得</p><p><b> 3-14</b></p><p><b> 式中——帶的根數(shù)
34、;</b></p><p><b> ——計算功率;</b></p><p><b> ——包角修正系數(shù);</b></p><p> ——V帶的帶長修正系數(shù);</p><p> ——單根普通V帶的基本額定功率;</p><p> ——單根普通V帶時額定功
35、率的增量</p><p> 傳動比為,查《機械設(shè)計基礎(chǔ)》可得=1.82、=0.22、=0.95、=1.07則</p><p><b> 取V帶根數(shù)為2。</b></p><p> ?。?)求作用在帶輪軸上的壓力F</p><p> 查《械設(shè)計基礎(chǔ)》13-1得V帶的單位長度質(zhì)量再由《械設(shè)計基礎(chǔ)》式13-17可得單根V
36、帶的初拉力為</p><p><b> 3-15</b></p><p><b> 作用在軸上的壓力為</b></p><p><b> 3-16</b></p><p> 3.3軸的設(shè)計與校核</p><p> 3.3.1軸的材料的選擇<
37、;/p><p> 選則軸的材料為45號鋼,調(diào)質(zhì)處理,硬度為, </p><p> 3.3.2各段軸的軸徑、軸長及軸承的確定</p><p> 圖3-1(輥子、軸示意圖)</p><p> 1-第一段軸;2-第二段軸;3-第三段軸;4-第四段軸;5-第五段軸;6-鍵;</p><p> 7-圓形鋼板;8輥子<
38、/p><p> 如圖3-1所示,粉碎機的輥子8中間做成空心以節(jié)省材料,兩端分別用鋼板7鑲嵌,軸焊接在鋼板上。前輥的軸承座固定安裝在焊接的機架上,后輥的軸承座裝在機架的導(dǎo)軌中,可在導(dǎo)軌上前后移動。</p><p> 由于所計算的軸與其他標(biāo)準(zhǔn)件不相連,軸的直徑可按扭轉(zhuǎn)強度進行估算,據(jù)《機械設(shè)計課程設(shè)計》P39公式</p><p><b> 3-17</
39、b></p><p> 可以得到,軸的最小直徑為:</p><p> 第1段軸連接大帶輪,大帶輪通過鍵以及軸端擋圈固定。軸的直徑等于大帶輪孔徑,軸的長度=,故=60mm,=64mm。</p><p> 第2段軸裝軸承和軸承蓋,據(jù)所選擇的軸承和軸承蓋的尺寸來確定軸的直徑</p><p><b> 和長度。</b&g
40、t;</p><p> 由于是軸間定位,故=,取。</p><p> 粉碎機工作時軸承主要承受徑向力,所以選擇深溝球軸承。據(jù)《機械設(shè)計課程設(shè)計》P191表9-18可知應(yīng)選的軸承型號為6213,B=23mm,,,。則第二段軸長為:</p><p><b> 3-18</b></p><p> 式中e為軸承蓋的厚度,
41、m由結(jié)構(gòu)確定,,,式中,為軸承蓋螺釘直徑,由中心距確定。據(jù)《機械設(shè)計課程設(shè)計》P59表4-17可知=24mm,從而=,取=10mm,,取.取</p><p><b> 則。</b></p><p> 第三段軸:由軸承的安裝尺寸可知,。==48。</p><p><b> 第四段軸:,。</b></p>
42、<p><b> 第五段軸:,。</b></p><p><b> 3.3.3軸的校核</b></p><p> ?。?).軸上的作用力的確定:</p><p> 查《非標(biāo)準(zhǔn)機械設(shè)備設(shè)計手冊》可知粉碎機粉碎物料所需的轉(zhuǎn)矩為:</p><p><b> 3-19</b
43、></p><p> 式中——理論粉碎功率(kW);</p><p> ——生產(chǎn)率(t/h);</p><p> ——輥子轉(zhuǎn)速(r/min)。</p><p> =0.3348=334.8</p><p><b> 3-20</b></p><p> 輥子
44、粉碎物料時物料對輥子有一個反作用力N,其方向指向輥子截面圓心,即輥子的徑向力為</p><p><b> 3-21</b></p><p> 粉碎機工作時物料對輥子還有一個摩擦力,它的作用是阻止輥子的轉(zhuǎn)動,方向沿輥子切線方向。當(dāng)這個摩擦力對輥子的轉(zhuǎn)矩等于時,粉碎機處于工作與不能工作的臨界狀態(tài),此時可以認(rèn)為輥子的最大切向力為:</p><p>
45、;<b> 3-22</b></p><p> 又(式中為物料與輥子間的摩擦系數(shù))</p><p><b> 故</b></p><p><b> 從而</b></p><p> ?。?).求垂直面的支承反力</p><p><b>
46、 3-23</b></p><p> ?。?).求水平面的支撐反力</p><p> ?。?).F力在支點產(chǎn)生的反力</p><p> ?。?).繪制垂直面的彎矩圖</p><p> (6).繪制水平面的彎矩圖</p><p> ?。?).F力產(chǎn)生的彎矩圖</p><p> a-
47、a截面F力產(chǎn)生的彎矩為:</p><p><b> (8)求合成彎矩:</b></p><p> 考慮到最不利的條件下,與直接相加得:</p><p> (9)求危險截面的當(dāng)量彎矩</p><p> 由圖可知a-a截面最危險,其當(dāng)量彎矩為</p><p><b> 3-24&l
48、t;/b></p><p> 如果認(rèn)為軸的扭切應(yīng)力是脈動循環(huán)變應(yīng)力,取折合系數(shù)=0.6,代入上式可得</p><p> (11).計算危險截面處軸的直徑:</p><p> 軸的材料選用45鋼,調(diào)質(zhì)處理,由《機械設(shè)計基礎(chǔ)》P241的表14-1,知,查《機械設(shè)計基礎(chǔ)》P246表14-3得,則</p><p><b> 3
49、-25</b></p><p> 考慮到鍵槽對軸的消弱,將值加大5%,故</p><p> 綜上可知軸的設(shè)計合格。</p><p> 圖3-2(軸的受力圖)</p><p> 3.3.4滾動軸承的校核</p><p> 本減速器的軸承型號為6213,查《機械設(shè)計基礎(chǔ)》附錄,得</p>
50、<p> ?。?).當(dāng)量動載荷P的計算</p><p> 該軸承只承受,不受,即 ,所以取X=1,Y=0</p><p> 考慮徑向力最大的情況則=2010.8N</p><p> (2).徑向基本額定動載荷的計算:</p><p> 由于工作溫度<100°,則,工作時有中等沖擊,取,</p>
51、<p><b> ,,</b></p><p><b> 3-26</b></p><p> 因為,所以選6213型號的軸承是合適的。</p><p> 3.3.5鍵的設(shè)計與校核</p><p><b> ?。?)鍵的選擇:</b></p>&
52、lt;p> 由=60,查《機械設(shè)計基礎(chǔ)》P156表10-9,選用圓頭普通平鍵,,,因為第一段長度=64,</p><p><b> 則鍵長,取。</b></p><p><b> (2)鍵的校核:</b></p><p> 設(shè)載荷分布均勻,由于輪轂的材料為鋼,輕微沖擊,由《機械設(shè)計基礎(chǔ)》P158表10-10,
53、知許用擠壓應(yīng)力=120MPa。查《機械設(shè)計基礎(chǔ)》P206頁可得公式:</p><p> 式中——帶輪上的圓周力;</p><p><b> ——帶速;</b></p><p><b> ——傳遞功率。</b></p><p> 可得 已知 </p><p>&
54、lt;b> 所以</b></p><p> 從而第一段軸的轉(zhuǎn)矩為=65275</p><p><b> 計算鍵的擠壓應(yīng)力</b></p><p><b> 其中</b></p><p><b> 故所設(shè)計的鍵合格。</b></p>&l
55、t;p> 4、其他零部件及結(jié)構(gòu)的設(shè)計</p><p><b> 4.1機架的設(shè)計</b></p><p> 粉碎機的機架采用邊長55mm的方鋼焊接而成,并且固定在地面上。根據(jù)粉碎機輥子以及軸的尺寸,初步確定機架的尺寸</p><p><b> 機架長為: </b></p><p>&l
56、t;b> 4-1</b></p><p><b> 式中:——輥子直徑</b></p><p><b> ——輥子間最大間隙</b></p><p> ——輥子側(cè)面與蓋子之間的間隙</p><p><b> ——方鋼的邊長</b></p>
57、<p><b> 取 則</b></p><p> 為了實際加工的方便取</p><p><b> 機架寬為:</b></p><p><b> 4-2</b></p><p> 式中:B——滾動軸承的寬度</p><p><
58、;b> ——輥子長度</b></p><p><b> ——第三段軸的長度</b></p><p><b> ——第六段軸的長度</b></p><p> m——由結(jié)構(gòu)確定(m=16)</p><p> 兩個V帶輪的中心距為991,根據(jù)粉碎機結(jié)構(gòu)取定機架的支柱高度為900
59、。具體尺寸見附錄1。</p><p><b> 4.2罩子的設(shè)計</b></p><p> 粉碎機的蓋子用薄鐵皮制成,長與機架相同,寬在機架尺寸的基礎(chǔ)上兩邊各加15mm,即寬為384mm。進料口位于兩輥子上方,為了方便進料和生產(chǎn)其尺寸定為。進料口上裝一個用薄鐵皮做成的進料漏斗,進料漏斗的斜面與蓋子上表面的夾角為45度,垂直高度為50mm,具體尺寸見附錄1。<
60、/p><p><b> 4.3其他</b></p><p> 前輥的軸承座固定安裝在機架上,后輥的軸承座裝在導(dǎo)軌上并可前后移動,導(dǎo)軌由底座與蓋子組成,固定安裝在機架上。軸承座、軸承蓋、導(dǎo)軌的具體尺寸見附錄1。</p><p><b> 5、結(jié)論</b></p><p> 輥子粉碎機的設(shè)計,主要是
61、以設(shè)計為主,即運用所學(xué)的工程制圖及機械設(shè)計等相關(guān)知識設(shè)計出所需要的裝置。由設(shè)計所需選擇深溝球軸承6213,軸材料選擇選45號鋼,調(diào)質(zhì)處理,經(jīng)校核軸與軸承均滿足使用要求。其它零部件經(jīng)過設(shè)計和校核,均滿足使用要求。通過設(shè)計所得出的輥子粉碎機,結(jié)構(gòu)緊湊合理,滿足預(yù)期要求。</p><p> 本次設(shè)計有許多不足之處,如V帶大帶輪直徑過大、進料粒度偏小等、粉碎機功率偏小等。通過本次畢業(yè)設(shè)計使我對自己所學(xué)的知識有了更深的理
62、解,了解到了自己的不足,在以后的工作中我會繼續(xù)學(xué)習(xí),彌補自己的缺點。</p><p><b> 致謝 </b></p><p> 我的畢業(yè)設(shè)計是在指導(dǎo)老師XX的細(xì)心指導(dǎo)下得以完成,**老師雖身負(fù)教學(xué)等工作,但仍百忙中抽出時間耐心指導(dǎo)并無時無刻關(guān)心我論文的進展,他嚴(yán)謹(jǐn)細(xì)致、一絲不茍的作風(fēng)一直是我工作、學(xué)習(xí)中的榜樣在此向老師教誨之情致以衷心感謝和崇高的敬意!同時在做畢
63、業(yè)設(shè)計的過程中我得到了身邊同學(xué)的幫助,他們給我提出了寶貴的建議,在此向他們表示感謝。</p><p><b> 參考文獻</b></p><p> [1]范欽珊等.工程力學(xué)[M].北京:高等教育出版社,2002.6.</p><p> [2]侯旭明.金屬力學(xué)性能[M].北京:機械工業(yè)出版社,2000.</p><p&g
64、t; [3]史美堂.金屬材料及熱處理[M].上海:上??茖W(xué)技術(shù)出版社,2005.</p><p> [4]楊可楨.機械設(shè)計基礎(chǔ)[M].北京:高等教育出版社,2006.等.</p><p> [5]陸鳳儀.機械設(shè)計[M]. 北京:高等教育出版社,2007.7.</p><p> [6]孫寶鈞.機械設(shè)計課程設(shè)計.[M].北京:機械工業(yè)出版社,1994.</
65、p><p> [7]成大先.機械設(shè)計手冊(軸承).[M].北京:化學(xué)工業(yè)出版社,2004.1</p><p> [7]成大先.機械設(shè)計手冊(軸及其連接).[M].北京:化學(xué)工業(yè)出版社,2004.1.</p><p> [9]曲玉峰.機械設(shè)計基礎(chǔ).北京:中國林業(yè)出版社:北京大學(xué)出版社,2006.7.</p><p> [10]孫德志.機械設(shè)
66、計基礎(chǔ)課程設(shè)計.北京:科學(xué)出版社,2006.</p><p> [11]高文龍,常燕賓[M]. 北京:機械工業(yè)出版社,2006. </p><p> [12]陶珍東,鄭少華[M].北京:化學(xué)工業(yè)出版社,2008.</p><p><b> 附錄1</b></p><p><b> 附錄2</b&g
67、t;</p><p> Transmission System introduced</p><p> The important position of the wheel gear and shaft can’t falter in traditional machine and modern machines. The wheel gear and shafts mainly i
68、nstall the direction that delivers the dint at the principal axis box. The passing to process to make them can is divided into many model numbers, used for many situations respectively. so we must be the multilayers to t
69、he understanding of the wheel gear and shaft in many ways.</p><p> In the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three d
70、imensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also
71、 other reasons, as we shall learn.</p><p> Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the othe
72、r a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this
73、paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge </p><p> The initial contact of spur-gear teeth is a line extending all the way across th
74、e face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotati
75、on; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability</p><p>
76、; Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor interesting. The teeth of crossed-helical fears have point contact with each other which changes to line contact as t
77、he gears wear in. for this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between
78、 a crossed helical gear and a helical gear until they are mount</p><p> Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they c
79、ompletely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction betwee
80、n nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvatu</p><p> Worm gearing are either single or double enveloping
81、. A single-enveloping gearing is one in which the gear wraps around or partially encloses the worm. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The import
82、ant difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand
83、 of helix</p><p> When gears are to be used to transmit motion between intersecting shaft, some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produ
84、ced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing
85、 this means that shaft deflection can be more pronounced and have a greater effect in the co</p><p> Straight bevel gears are easy to design and simple to manufacture and give very good results in service i
86、f they are mounted accurately and positively. As in the case of squrgears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often good design practice to go to the spiral bevel
87、 gear, which is the bevel counterpart of the helical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and</p><p> It is frequently desir
88、able, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolutio
89、n The tooth action between such gears is a combination of rolling and has much in common with that of worm gears.</p><p> A shaft is a rotating or stationary member usually of circular cross section, having
90、 mounted upon it such elementsas gears pulleys flywheels, cranks sprockets and other power-transmission elements Shaft may be subjected to bending tension compression or torsional loads acting singly or in combination wi
91、th one another .When they are combined one may expect to find both static and fatigue strength to be important design considerations since a single shaft may be subjected to static stresses comple</p><p> T
92、he word “shaft” covers numerous wariations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating nor subjected to torsion load. Ashirt rotating shaft is often called a spindle.</p><p>
93、; When either the lateral or the to sional deflection of shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses The reason for this is that if the shift is m
94、ade stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are within acceptable limits. Whenever possible the
95、power-transmission elements such as gears or pullets, should be</p><p> Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably come closest to predicting actual fai
96、lure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft that has already been designed or of discovering why a particular shaft has failed in service. Furth
97、ermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as r</p><p> Because of the similarity of their functions, clutc
98、hes and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two inertias I1and I2 traveling at the respective angular velocities W1 and W2, one of which may be zero in the
99、case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a tempe
100、rature ri</p><p> Rim type with internally expanding shoes </p><p> Rim type with internally contracting shoes</p><p> Band type </p><p> Disk or axial type </p&
101、gt;<p><b> Cone type</b></p><p> Miscellaneous type</p><p> The analysis of all type of friction clutches and brakes use the same general procedure. The following step are
102、necessary:</p><p> 1. Assume or determine the distribution of pressure on the frictionalsurfaces.</p><p> 2. Find a relation between the maximum pressure and the pressure at any point </p&g
103、t;<p> 3. apply the condition of statical equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions. </p><p> Miscellaneous clutches include several type, such as th
104、e positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others.</p><p> A positive-contact clutch consists of a shift lever and two jaws. The greatest diff
105、erences between the various types of positive clutches are concerned with the design of the jaws. To provide a longer period of time for shift action during engagement, the jaws may be ratchet-shaped, or gear-tooth-shape
106、d. Sometimes a great many teeth or jaws re used, and they may be cut either circumferentially, so that they engage by cylindrical mating, or on the faces of the mating elements.</p><p> Although positive cl
107、utches are not used to the extent the frictional-contact type, they do have important applications where synchronous operation is required.</p><p> Devices such as linear driver or motor-operated screw driv
108、ers must run to definite limit and then come to a stop. An over load-release rype of clutch is required for these applications. These clutches are usually spring-loaded so as to release at a predetermined toque. The clic
109、king sound which is heard when the overload point is reached is considered to be a desirable signal.</p><p> An overrunning clutch or coupling permits the driven member of a machine to “freewheel” or “overr
110、un” because the driver is stopped or because another source of power increase the speed of the driven. This type of clutch usually uses rollers or balls mounted between an outer sleeve and an inner member having flats ma
111、chined around the periphery. Driving action is obtained by wedding the rollers between the sleeve and the flats. The clutch is therefore equivalent to a pawl and ratchet with an infin</p><p> Magnetic fluid
112、 clutch or brake is a relatively new development which has two parallel magnetic plates. Between these plates is a lubricated magnetic powder mixture. An electromagnetic coil is inserted somewhere in the magnetic circuit
113、. Bu varying the excitation to this coil, the shearing strength of the magnetic fluid mixture may be accurately controlled. Thus any condition from a full slip to a frozen lockup may be obtained.</p><p><
114、b> 機械傳動系統(tǒng)介紹</b></p><p> 在傳統(tǒng)機械和現(xiàn)代機械中齒輪和軸的重要地位是不可動搖的。齒輪和軸主要安裝在主軸箱來傳遞力的方向。通過加工制造它們可以分為許多的型號,分別用于許多的場合。所以我們對齒輪和軸的了解與認(rèn)識必須是多層次多方位的。</p><p> 在直齒圓柱齒輪的受力分析中,是假設(shè)各力作用在單一平面的。我們將研究作用力具有三維坐標(biāo)的齒輪。因此
115、,在斜齒輪的情況下,其齒向是不平行于回轉(zhuǎn)軸線的。而在錐齒輪的情況中各回轉(zhuǎn)軸線互相不平行。像我們要討論的那樣,尚有其它道理需要學(xué)習(xí),掌握。</p><p> 斜齒輪用于傳遞平行軸之間的運動。傾斜角度每個齒輪都一樣,但一個必須右旋斜齒,而另一個必須是左旋斜齒。齒的形狀是一漸開線螺旋面。如果一張被剪成平行四邊形(矩形)的紙張包圍在齒輪圓柱體上,之上印出齒的角刃邊就變成斜線。如果我展開這張紙,在斜角刃邊上的每一個點就發(fā)
116、生一漸開線曲線。</p><p> 直齒圓柱齒輪輪齒的初始接觸處是跨過整個齒面而伸展開來的線。斜齒輪輪齒的初始接觸是一點,當(dāng)齒進入更多的嚙合時,它就變成線。在直齒圓柱齒輪中,接觸是平行于回轉(zhuǎn)軸線的。在斜齒輪中,該線是跨過齒面的對角線。它是齒輪逐漸進行嚙合并平穩(wěn)的從一個齒到另一個齒傳遞運動,那樣就使斜齒輪具有高速重載下平穩(wěn)傳遞運動的能力。斜齒輪使軸的軸承承受徑向和軸向力。當(dāng)軸向力變的大了或由于別的原因而產(chǎn)生某些影
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