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1、單擊此處編輯母版標(biāo)題樣式,單擊此處編輯母版文本樣式,第二級(jí),第三級(jí),第四級(jí),第五級(jí),*,由于軸承安裝情況與受載情況的復(fù)雜性，計(jì)算軸承的徑向力與軸向力時(shí)不要死記公式，而是要學(xué)會(huì)根據(jù)具體情況進(jìn)行具體分析，步驟為：,*根據(jù),F,r,求出,F,r1,和,F,r2,。,*,按表137估計(jì),F,d1,和,F,d2,的值，它們的方向視軸承安裝方向而定。注意把派生軸向力的方向與外加軸向載荷,F,ae,的方向一致的軸承標(biāo)記為2，另一端的軸承標(biāo)記為1。,*由于軸承最終必須處于平衡狀態(tài)，所以,F,d1,和,F,d2,的值最后有一個(gè)要變化到,F,d,，,以便與,F,ae,一起達(dá)到軸向力的平衡。當(dāng),F,ae,F,d2,

2、F,d1,則,F,d1,應(yīng)增大到,F,d1,，,使,F,d1,F,ae,F,d2,，,而,F,d2,則不變。當(dāng),F,ae,F,d2,F,d1,時(shí)，為,F,d1,F,d1，,F,a2,F,d2,；,當(dāng),F,ae,F,d2,e,名 稱(chēng) 代 號(hào),f,0,F,a,/C,0r,F,a,/C,0,X Y X Y,判斷系數(shù),e,調(diào)心球軸承 10000,1 (,Y,1,)0.65 (Y,2,)(e),調(diào)心滾子軸承 20000,1 (,Y,1,)0.67 (Y,2,)(e),推力調(diào)心滾子軸承,29000,1 1.2 1 1.2,圓錐滾子軸承 30000,1 0 0.4 (,Y)(e),深溝球軸承 60000,角

3、接觸球軸承,0.172 2.30 0.19,0.345 1.99 0.22,0.689 1.71 0.26,1.030 1.55 0.28,1.380,1 0 0.56 1.45 0.30,2.070 1.31 0.34,3.450 1.15 0.38,5.170 1.04 0.42,6.890 1.00 0.44,0.015 1.47 0.38,0.029 1.40 0.40,0.058 1.30 0.43,0.087 1.23 0.46,0.120 1 0 0.44 1.19 0.47,0.170 1.12 0.50,0.290 1.02 0.55,0.440 1.00 0.56,0.58

4、0 1.00 0.56,1 0 0.41 0.87 0.68,1 0 0.35 0.57 1.14,70000AC,=2,5,70000B,=,40,70000C,=1,5,表13-5 徑向動(dòng)載荷系數(shù),X,與軸向動(dòng)載系數(shù),Y,因?yàn)?F,a,未知，初選,e=,0.4,0.40,F,d1,=eF,r1,F,d2,=eF,r2,于是,F,a1,=,F,ae,+F,d2,F,a2,=F,d2,=,605.05 N,F,a1,/C,0,=1005.05/20000=,0.0503,F,a2,/C,0,=605.05/20000=,0.0303,重新查表選取判斷系數(shù),e,內(nèi)部軸向力:,=0.4,875.6

5、5=350.26 N,=0.4,1512.62=605.05 N,=400+,605.05=1005.05 N,軸承類(lèi)型 相對(duì)軸向載荷,F,a,/,F,r,e,F,a,/,F,r,e,名 稱(chēng) 代 號(hào),f,0,F,a,/C,0r,F,a,/C,0,X Y X Y,判斷系數(shù),e,調(diào)心球軸承 10000,1 (,Y,1,)0.65 (Y,2,)(e),調(diào)心滾子軸承 20000,1 (,Y,1,)0.67 (Y,2,)(e),推力調(diào)心滾子軸承,29000,1 1.2 1 1.2,圓錐滾子軸承 30000,1 0 0.4 (,Y)(e),深溝球軸承 60000,角接觸球軸承,0.172 2.30 0.1

6、9,0.345 1.99 0.22,0.689 1.71 0.26,1.030 1.55 0.28,1.380,1 0 0.56 1.45 0.30,2.070 1.31 0.34,3.450 1.15 0.38,5.170 1.04 0.42,6.890 1.00 0.44,0.015 1.47 0.38,0.029 1.40 0.40,0.058 1.30 0.43,0.087 1.23 0.46,0.120 1 0 0.44 1.19 0.47,0.170 1.12 0.50,0.290 1.02 0.55,0.440 1.00 0.56,0.580 1.00 0.56,1 0 0.41

7、 0.87 0.68,1 0 0.35 0.57 1.14,70000AC,=2,5,70000B,=,40,70000C,=1,5,表13-5 徑向動(dòng)載荷系數(shù),X,與軸向動(dòng)載系數(shù),Y,0.029,沒(méi)有相同的值0.0503,0.40,0.058 0.43,F,a,/C,0,表中沒(méi)有與計(jì)算結(jié)果相同的,F,a1,/C,0,值，采用線性插值法求,e,0.058 0.43,(0.029 0.4),線性插值的原理,角的正切值為對(duì)邊比鄰邊,0.0503,e,1,重新查表選取判斷系數(shù),e,重新計(jì)算軸向力,F,d1,=e,1,F,r1,=0.422,875.65=369.52 N,F,d2,=e,2,F,r2

8、,=0.401,1512.62=606.56 N,e,1,=0.422 e,2,=0.401,F,a1,=,F,ae,+F,d2,F,a2,=F,d2,=,606.56 N,F,a1,/C,0,=1006.56/20000=,0.05033,F,a2,/C,0,=606.56/20000=,0.03033,兩次計(jì)算,F,a2,/C,0,結(jié)果相差不大，故取,重新計(jì)算軸向力,e,1,=0.422,e,2,=0.401,F,a1,=,1006.56 N,F,a2,=,606.56 N,=400+,606.56=1006.56 N,3.,求軸承的當(dāng)量載荷,P,1,和,P,2,查下頁(yè)表并插值可求得徑向載

9、荷系數(shù),X,和軸向載荷系數(shù),Y,軸承類(lèi)型 相對(duì)軸向載荷,F,a,/,F,r,e,F,a,/,F,r,e,名 稱(chēng) 代 號(hào),f,0,F,a,/C,0r,F,a,/C,0,X Y X Y,判斷系數(shù),e,調(diào)心球軸承 10000,1 (,Y,1,)0.65 (Y,2,)(e),調(diào)心滾子軸承 20000,1 (,Y,1,)0.67 (Y,2,)(e),推力調(diào)心滾子軸承,29000,1 1.2 1 1.2,圓錐滾子軸承 30000,1 0 0.4 (,Y)(e),深溝球軸承 60000,角接觸球軸承,0.172 2.30 0.19,0.345 1.99 0.22,0.689 1.71 0.26,1.030

10、1.55 0.28,1.380,1 0 0.56 1.45 0.30,2.070 1.31 0.34,3.450 1.15 0.38,5.170 1.04 0.42,6.890 1.00 0.44,0.015 1.47 0.38,0.029 1.40 0.40,0.058 1.30 0.43,0.087 1.23 0.46,0.120 1 0 0.44 1.19 0.47,0.170 1.12 0.50,0.290 1.02 0.55,0.440 1.00 0.56,0.580 1.00 0.56,1 0 0.41 0.87 0.68,1 0 0.35 0.57 1.14,70000AC,=2

11、,5,70000B,=,40,70000C,=1,5,表13-5 徑向動(dòng)載荷系數(shù),X,與軸向動(dòng)載系數(shù),Y,采用線性插值法求,Y,1,對(duì)軸承1,X,1,=0.44 Y,1,=1.327,1.30 0.43,(1.40 0.4),1.40 0.40,1.30 0.43,表中沒(méi)有,e=0.422,Y,1,0.422,軸承2,X,2,=1 Y,2,=0,軸承工作時(shí)有中等沖擊載荷，查表取,表13-6 載荷系數(shù),載荷性質(zhì) 載荷系數(shù),f,P,無(wú)沖擊或輕微沖擊,1.01.2,中等沖擊,1.21.8,強(qiáng)烈沖擊,1.83.0,應(yīng)用舉例,電機(jī)、汽輪機(jī)、通風(fēng)機(jī)、水泵等,機(jī)床、車(chē)輛、動(dòng)力機(jī)械、起重機(jī)、造紙機(jī)、選礦基、冶

12、金機(jī)械、卷?yè)P(yáng)機(jī)等,碎石機(jī)、軋鋼機(jī)、鉆探機(jī)、振動(dòng)篩等,1.21.8,軸承的當(dāng)量載荷:,P,1,=,f,p,(X,1,F,r1,+Y,1,F,a1,),P,2,=,f,p,(X,2,F,r2,+Y,2,F,a2,),=1.5,(0.44,875.65+1.327,1006.56)=2581.49 N,=1.5,(1,1512.62+0,606.56)=2268.93 N,f,p,=1.5,4.,驗(yàn)算軸承壽命,P,1,P,2,所以按軸承1的壽命計(jì)算,所選軸承滿足壽命要求。,13-4,一農(nóng)用水泵，決定選用深溝球軸承，軸頸直徑,d=35mm，,轉(zhuǎn)速,n=2900 r/min。,已知徑向載荷,F,r,=1

13、810N，,軸向載荷,F,a,=740N，,預(yù)期計(jì)算壽命,L,h,=6000，,試選擇軸承型號(hào)。,解：1 求比值,F,a,/,F,r,=,740/1810=0.41,查表13-5，,X=0.56，Y=1.65,相對(duì)軸向載荷,f,0,F,a,/C,0r,=14.7740/15200=0.716，,對(duì)應(yīng),e,值在0.26和0.28之間,2,初選軸承型號(hào)：6207，,C=25500 N，C,0,=15200 N,P=X F,r,+Y F,a,=2234.6 N,L=8545 h,驗(yàn)算,Y1.55+(1.71-1.55)*,(1.03-0.716)/(1.03-0.689)=1.6973,L=4714

14、 h,P=X F,r,+Y F,a,=2269.6 N,選軸承型號(hào)：,6307,，,C=33200 N,C,0,=19200 N,相對(duì)軸向載荷,f,0,F,a,/C,0r,=14.7740/19200=0.56656，,對(duì)應(yīng),e,值在0.22和0.26之間.,查表13-5，,X=0.56,P=X F,r,+Y F,a,=2352.72N,L=9345.67 h,Y=1.71+(1.99-1.71)*(0.689-0.56656)/(0.689-0.345)=1.81,13-5,根據(jù)工作條件，決定在軸的兩端選用,=25,0,的兩個(gè)角接觸球軸承，如圖,示。軸頸直徑,d=35mm，,工作中有中等沖擊

15、，轉(zhuǎn)速,n=1800r/min，,已知兩軸,承的徑向載荷分別為,F,r1,=3390N，F(xiàn),r2,=1040N，,外加軸向載荷,F,ae,=870N，,作用,方向指向軸承1，試確定其工作壽命。,解：對(duì)于70000,AC,型軸承,F,d,=0.68F,r,1,F,ae,F,r2,F,r1,F,d2,F,d1,2,正裝,F,d1,=0.68F,r1,=0.683390=2305.2N,F,d2,=0.68F,r1,=0.681040=707.2N,按,F,a1,=,F,ae,+F,d2,=1577.2 N F,d1,，,F,a1,=,F,d1,=2305.2N,F,a2,=F,d1,F,ae,=1

16、435.2N,F,a1,/F,r1,=0.68,e=0.68,查表13-5，,X=1，Y=0,F,a2,/F,r2,=1.38,查表13-5，,X=0.41，Y=0.87,P,1,=,XF,r,=3390 N,P,2,=,XF,r,+,YF,a,=0.411040+0.871435.2=1675N,查表（國(guó)家標(biāo)準(zhǔn)）：7207,AC,軸承的,C=30500N,L,h,=1998 h,復(fù)習(xí)思考題：,1、滾動(dòng)軸承由哪些基本元件組成？它們的作用是什么？,2、滾動(dòng)軸承有哪些類(lèi)型？試比較3、6、7、,N,這四種類(lèi)型軸承,的主要特點(diǎn)和適用場(chǎng)合？,3、軸承代號(hào)的前置、基本和后置代號(hào)各代表什么意義？,4、為什么內(nèi)圈固定、外圈轉(zhuǎn)動(dòng)時(shí)，作用在固定套圈上的載荷的,變化頻率比內(nèi)圈轉(zhuǎn)動(dòng)、外圈固定時(shí)要高一些？,5、什么是滾動(dòng)軸承的接觸角？什么是載荷角？它們之間有沒(méi)有,聯(lián)系？,6、為什么軸向力的大小會(huì)影響某些類(lèi)型軸承的承載滾動(dòng)體數(shù)目？,7、滾動(dòng)軸承類(lèi)型的選擇應(yīng)考慮哪些因素？高速輕載的工作條件,宜選用哪一類(lèi)軸承？高速重載又宜選用哪一類(lèi)軸承？,8、什么叫游動(dòng)支撐？在什么情況下采用?,9、,什么叫滾動(dòng)軸承的基本額定壽命？什