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減速器的組成構(gòu)造


減速器簡介用于降低轉(zhuǎn)速、傳遞動力、增大轉(zhuǎn)矩的獨立傳動部件。減速器是原動機和工作機之間的獨立的閉式傳動裝置,用來降低轉(zhuǎn)速和增大轉(zhuǎn)矩,以滿足工作需要,在某些場合也用來增速,稱為增速器。選用減速器時應(yīng)根據(jù)工作機的選用條件,技術(shù)參數(shù),動力機的性能,經(jīng)濟性等因素,比較不同類型、品種減速器的外廓尺寸,傳動效率,承載能力,質(zhì)量,價格等,選擇最適合的減速器。減速器是一種相對精密的機械,使用它的目的是降低轉(zhuǎn)速,增加轉(zhuǎn)矩。

 


  基本構(gòu)造減速器主要由傳動零件(齒輪或蝸桿)、軸、軸承、箱體及其附件所組成。其基本結(jié)構(gòu)有三大部分:

 


  1、齒輪、軸及軸承組合

 


  小齒輪與軸制成一體,稱齒輪軸,這種結(jié)構(gòu)用于齒輪直徑與軸的直徑相關(guān)不大的情況下,如果軸的直徑為d,齒輪齒根圓的直徑為df,則當(dāng)df-d≤6~7mn時,應(yīng)采用這種結(jié)構(gòu)。而當(dāng)df-d>6~7mn時,采用齒輪與軸分開為兩個零件的結(jié)構(gòu),如低速軸與大齒輪。此時齒輪與軸的周向固定平鍵聯(lián)接,軸上零件利用軸肩、軸套和軸承蓋作軸向固定。兩軸均采用了深溝球軸承。這種組合,用于承受徑向載荷和不

 


  大的軸向載荷的情況。當(dāng)軸向載荷較大時,應(yīng)采用角接觸球軸承、圓錐滾子軸承或深溝球軸承與推力軸承的組合結(jié)構(gòu)。軸承是利用齒輪旋轉(zhuǎn)時濺起的稀油,進行潤滑。箱座中油池的潤滑油,被旋轉(zhuǎn)的齒輪濺起飛濺到箱蓋的內(nèi)壁上,沿內(nèi)壁流到分箱面坡口后,通過導(dǎo)油槽流入軸承。當(dāng)浸油齒輪圓周速度υ≤2m/s時,應(yīng)采用潤滑脂潤滑軸承,為避免可能濺起的稀油沖掉潤滑脂,可采用擋油環(huán)將其分開。為防止?jié)櫥土魇Ш屯饨缁覊m進入箱內(nèi),在軸承端蓋和外伸軸之間裝有密封元件。

 


  2、箱體

 


  箱體是減速器的重要組成部件。它是傳動零件的基座,應(yīng)具有足夠的強度和剛度。

 


  箱體通常用灰鑄鐵制造,對于重載或有沖擊載荷的減速器也可以采用鑄鋼箱體。單體生產(chǎn)的減速器,為了簡化工藝、降低成本,可采用鋼板焊接的箱體。

 


  灰鑄鐵具有很好的鑄造性能和減振性能。為了便于軸系部件的安裝和拆卸,箱體制成沿軸心線水平剖分式。上箱蓋和下箱體用螺栓聯(lián)接成一體。軸承座的聯(lián)接螺栓應(yīng)盡量靠近軸承座孔,而軸承座旁的凸臺,應(yīng)具有足夠的承托面,以便放置聯(lián)接螺栓,并保證旋緊螺栓時需要的扳手空間。為保證箱體具有足夠的剛度,在軸承孔附近加支撐肋。為保證減速器安置在基礎(chǔ)上的穩(wěn)定性并盡可能減少箱體底座平面的機械加工面積,箱體底座一般不采用完整的平面。

 


  3、減速器附件

 


  為了保證減速器的正常工作,除了對齒輪、軸、軸承組合和箱體的結(jié)構(gòu)設(shè)計給予足夠的重視外,還應(yīng)考慮到為減速器潤滑油池注油、排油、檢查油面高度、加工及拆裝檢修時箱蓋與箱座的精確定位、吊裝等輔助零件和部件的合理選擇和設(shè)計。

 


  1)檢查孔為檢查傳動零件的嚙合情況,并向箱內(nèi)注入潤滑油,應(yīng)在箱體的適當(dāng)位置設(shè)置檢查孔。檢查孔設(shè)在上箱蓋頂部能直接觀察到齒輪嚙合部位處。平時,檢查孔的蓋板用螺釘固定在箱蓋上。

 


  2)通氣器減速器工作時,箱體內(nèi)溫度升高,氣體膨脹,壓力增大,為使箱內(nèi)熱脹空氣能自由排出,以保持箱內(nèi)外壓力平衡,不致使?jié)櫥脱胤窒涿婊蜉S伸密封件等其他縫隙滲漏,通常在箱體頂部裝設(shè)通氣器。

 


  3)軸承蓋為固定軸系部件的軸向位置并承受軸向載荷,軸承座孔兩端用軸承蓋封閉。軸承蓋有凸緣式和嵌入式兩種。利用六角螺栓固定在箱體上,外伸軸處的軸承蓋是通孔,其中裝有密封裝置。凸緣式軸承蓋的優(yōu)點是拆裝、調(diào)整軸承方便,但和嵌入式軸承蓋相比,零件數(shù)目較多,尺寸較大,外觀不平整。

 


  4)定位銷為保證每次拆裝箱蓋時,仍保持軸承座孔制造加工時的精度,應(yīng)在精加工軸承孔前,在箱蓋與箱座的聯(lián)接凸緣上配裝定位銷。安置在箱體縱向兩側(cè)聯(lián)接凸緣上,對稱箱體應(yīng)呈對稱布置,以免錯裝。

 


  5)油面指示器檢查減速器內(nèi)油池油面的高度,經(jīng)常保持油池內(nèi)有適量的油,一般在箱體便于觀察、油面較穩(wěn)定的部位,裝設(shè)油面指示器。

 


  6)放油螺塞換油時,排放污油和清洗劑,應(yīng)在箱座底部,油池的最低位置處開設(shè)放油孔,平時用螺塞將放油孔堵住,放油螺塞和箱體接合面間應(yīng)加防漏用的墊圈。

 


  7)啟箱螺釘為加強密封效果,通常在裝配時于箱體剖分面上涂以水玻璃或密封膠,因而在拆卸時往往因膠結(jié)緊密難于開蓋。為此常在箱蓋聯(lián)接凸緣的適當(dāng)位置,加工出~2個螺孔,旋入啟箱用的圓柱端或平端的啟箱螺釘。旋動啟箱螺釘便可將上箱蓋頂起。小型減速器也可不設(shè)啟箱螺釘,啟蓋時用起子撬開箱蓋,啟箱螺釘?shù)拇笮】赏谕咕壜?lián)接螺栓。

 


  基本分類1、減速器按用途可分為通用減速器和專用減速器兩大類,兩者的設(shè)計、制造和使用特點各不相同。20世紀(jì)70-80年代,世界上減速器技術(shù)有了很大的發(fā)展,且與新技術(shù)革命的發(fā)展緊密結(jié)合。其主要類型:齒輪減速器;蝸桿減速器;齒輪—蝸桿減速器;行星齒輪減速器。

 


  2、一般的減速器有斜齒輪減速器(包括平行軸斜齒輪減速器、蝸輪減速器、錐齒輪減速器等等)、行星齒輪減速器、擺線針輪減速器、蝸輪蝸桿減速器、行星摩擦式機械無級變速機等等。

 


  1)圓柱齒輪減速器

 


  單級、二級、二級以上二級。布置形式:展開式、分流式、同軸式。

 


  2)圓錐齒輪減速器

 


  用于輸入軸和輸出軸位置成相交的場合。

 


  3)蝸桿減速器

 


  主要用于傳動比i>10的場合,傳動比較大時結(jié)構(gòu)緊湊。其缺點是效率低。目前廣泛應(yīng)用阿基米德蝸桿減速器。

 


  4)齒輪—蝸桿減速器

 


  若齒輪傳動在高速級,則結(jié)構(gòu)緊湊;

 


  若蝸桿傳動在高速級,則效率較高。

 


  5)行星齒輪減速器

 


  傳動效率高,傳動比范圍廣,傳動功率12W~50000KW,體積和重量小。

 


  3、常見減速器的種類

 


  1)蝸輪蝸桿減速器的主要特點是具有反向自鎖功能,可以有較大的減速比,輸入軸和輸出軸不在同一軸線上,也不在同一平面上。但是一般體積較大,傳動效率不高,精度不高。

 


  2)諧波減速器的諧波傳動是利用柔性元件可控的彈性變形來傳遞運動和動力的,體積不大、精度很高,但缺點是柔輪壽命有限、不耐沖擊,剛性與金屬件相比較差。輸入轉(zhuǎn)速不能太高。

 


  3)行星減速器其優(yōu)點是結(jié)構(gòu)比較緊湊,回程間隙小、精度較高,使用壽命很長,額定輸出扭矩可以做的很大。但價格略貴。減速器:簡言之,一般機器的功率在設(shè)計并制造出來后,其額定功率就不在改變,這時,速度越大,則扭矩(或扭力)越小;速度越小,則扭力越大。


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