西工大版機(jī)械設(shè)計(jì)答案第八版

3-1某材料的對(duì)稱循環(huán)彎曲疲勞極限”，取循環(huán)180MPa基數(shù),，試求循環(huán)次數(shù)N分別為0N5106m90o[解]5103373.6MPa%%18091N119■—1-N7101o901809---------324.3MPa1o901809---------324.3MPa443-2已知材料的力學(xué)性能為,,%260MPas170MPa化，試?yán)L制此材料的簡(jiǎn)化的等壽命壽命曲線。0.2T [解]''12%%1C0,0)2%1°0■%得 2170 0.2D'(283.332,283.332)283.33MPa'D(141.67,141.67)'根據(jù)點(diǎn),,按比例繪制A'(0,170)C(260,0)D'(141.67,141.67)A'(0.170)0"(141.C7,14).67)C(260.0；療”3-4圓軸軸肩處的尺寸為：D=72mm,d=62mm,r=3mm。如用題3-2中的材料，設(shè)其強(qiáng)度極限 [解]因,才舟，查附表3-2,插值得D44120.067d45d45,查附圖3-1得,將所查值代入公式，即1.88q0.78.(T(Tk1q110.781.881.ff.；按精車加工工藝，查附0.75k1$%k1$%-91.-91.10.75,貝已1U按比例繪岀該零件的60,0,D141.67,60.29D'(141.67,60-29)A'Q72.3*)-----—_.__-----\0O'(260r0)(7n3-5如題3-4中危險(xiǎn)截面上的平均應(yīng)力g20MPa,應(yīng)力幅g，試分別按①②,求岀該截面的計(jì)算安全系數(shù)20MParCC。Sca也170MPa,g260MPa,①0.2,A'(d72.34>一A'(d72.34>一tO,30)0.0)C(260.0.0)(1)rC系數(shù)1702.28(2)2.35300.2200Cm數(shù)Ko0°noo2.353020重機(jī)導(dǎo)軌托架。兩塊邊板各用4個(gè)螺栓栓連接 [解]采用鉸制孔用螺栓連接為宜抵抗(1)確定M6X40的許用切應(yīng)力[] []?640182.86~128MPa S3.5~5.0[[426^7MPa(2)螺栓組受到剪力F和力矩(),設(shè)剪力F分在各TFL個(gè)螺栓上的力為,轉(zhuǎn)矩T分在各個(gè)螺栓上的分力為F組，F(xiàn)j對(duì)稱中心的距離為r,即r11cos4575.2mmFiF.5kNFj8030033j8r8752103、F_F2i亙jijjij901510..2.52(52)222.552cos459.015kN319[]232d0d4610349.0151030min0min61011.4103相平行、距離為250mm、大小為60kN的載荷作用。現(xiàn)，設(shè)采用鉸制孔 [解]螺栓組受到剪力F和轉(zhuǎn)矩，設(shè)剪力F分在各個(gè)螺栓上的力為，轉(zhuǎn)矩T分在各個(gè)螺栓上的分力為FFj (a)中各螺栓軸線到螺栓組中心的距離為r，即r=125mmF-6010kNi6FL60250103Fj6r12510320kN由(a)圖可知，最左的螺栓受力最大max (b)方案中F-F16010kNi66jmax22i1262ii33602501024.39kN竺2b螺栓受力最大為ijij.39)221024.39kN44Fmax可知采用(a)布置形式所用的螺栓直徑較小5-10聲(1)禰定螺栓藪打[盲住d*iQ■=92MJIW-z蟀梓肯紹d=tO/^^/6=15.33IBTD+取d=」t)inn.」 □s=E00血民”口,=640A￡Fa*'F=-j?=7363U7’斗軒F取齡繭緊力Fl=l-5Ff由教材必式2〔5-15工螺栓旳總載荷*FL=FlhF=2.5F=2.慮曲辰1B34D陽(yáng)W)告坤應(yīng)力卜按不控制預(yù)緊力確定安全系數(shù).査教權(quán)袤5叫0,取畢冬許朋拉應(yīng)力*[亦=工=1加必" (叮驗(yàn)具甥住的強(qiáng)度。互手盼騾栓旳大徑獷瑋皿小稔dl-13.335^.取蘇栓公稱検.度l-70tim.曲教材金式 (5-1^.螺柱的L；茸應(yīng)力q廠丄翌二也.7血*回衛(wèi)41満足通度爺件.膘栓施標(biāo)^為GE/T&782-3^16x70,^栓數(shù)量曠12，6-3在一直徑的軸端，安裝一鋼制直齒圓柱齒輪d80mm (如下圖)，輪轂寬度，工作時(shí)有輕微沖擊。試確L1.5d [解]根據(jù)軸徑，查表得所用鍵的剖面尺寸丿為d80mmb，22mmh14mm根據(jù)輪轂長(zhǎng)度L'1.5d1.580120mm取鍵的公稱長(zhǎng)度L90mm鍵2290GB1096-79ILb902268mm2用擠壓應(yīng)力[Op]110MPa根據(jù)普通平鍵連接的強(qiáng)度條件公式Op2T1032094Nm2094Nm20002000第八章帶傳動(dòng)-1V帶傳動(dòng)的，帶與帶輪的當(dāng)量摩ni1450rmin(2)若，其傳遞的最大轉(zhuǎn)矩為多少？(3)dd1100mm若傳動(dòng)效率為0.95,彈性滑動(dòng)忽略不計(jì)，從動(dòng)丄4e [解]i斗0ec00ec0尹1占2TF4784e12Fecniddi1478.4Ne3需?nn1000601000?478414503141000.95昭3.4506010008-2V帶傳動(dòng)傳遞效率邊拉力是松邊拉力的兩倍，即FF2有效拉力和初拉力。FFe0FFve1000P10007.5750Nv101e2121e212 [解]FiFF02F1500750FF-4有一帶式輸送裝置，其異步電動(dòng)機(jī)與齒輪減速器之間用普通V帶傳動(dòng)，電動(dòng)機(jī)功率P=7kW，轉(zhuǎn)速，減速器輸入軸的轉(zhuǎn)速，nni960rminn2330r/mn允許誤差為，運(yùn)輸裝置工作時(shí)有輕度沖擊，兩班制工 [解](1)確定計(jì)算功率Pca由表8-7查得工作情況系數(shù)，故K1.2AFKP1.278.4kWCaA(2)選擇V帶的帶型Pcanl(3)確定帶輪的基準(zhǔn)直徑，并驗(yàn)算帶ddd①由表&6和準(zhǔn)直徑dd1180mmV馳1809609.0432ms6010006010005msV30ms帶速合適③計(jì)算從動(dòng)輪的基準(zhǔn)直徑1809601005497.45mm匕330①由式，0.7dd1dd2定和基準(zhǔn)長(zhǎng)度daLda02dd1dd2。Ld02a0dd1Ld02a02550—1805002dd2dd1 .4a°24550由表8-2選帶的基準(zhǔn)長(zhǎng)度L2240mmdddLL55022402214563mm dd02550~630mm(5)驗(yàn)算小帶輪上的包角Po3.25kW960ms,i180500180竽180500180(6)計(jì)算帶的根數(shù)①計(jì)算單根V帶的額定功率Pd180mm和m960m根2.9和B型帶，查表得F0.303kW查表8-5得,表8-2得,ka0.914kL1FrF0F0kakL(3.250.303)0.91413.25kW②計(jì)算v帶的根數(shù)PV值帶輪結(jié)構(gòu)設(shè)計(jì)(略)帶輪結(jié)構(gòu)設(shè)計(jì)(略)q018kg.mk2.k2aea2aeaaZv0aZv0.91439.0432pp2zF0minSin—N)9-2某鏈傳動(dòng)傳遞的功率，主動(dòng)鏈輪轉(zhuǎn)速,從Pikwni48rmn動(dòng)鏈輪轉(zhuǎn)速E,載荷平穩(wěn)，定期人工潤(rùn)滑，試設(shè)計(jì)14rmn [解](1)選擇鏈輪齒數(shù)ni481965z2z2IZ1zi14K1.0K1.52AzK1.0K1.52AzPKKP1.01.5211.52kWeaAZ(3)選擇鏈條型號(hào)和節(jié)距根據(jù)，查圖9-11,可選16A，Pca1.52kW及n148rmIn查表9-1，鏈條節(jié)距p25.4mm(4)計(jì)算鏈節(jié)數(shù)和中心距a(30~50)p(30~50)25.4762~1270mma0900mm2a°aZZ12ZZp2-2a6519空取鏈長(zhǎng)節(jié)數(shù)。pL114節(jié)p查表9-7得中心距計(jì)算系數(shù)，f10.24457(5)計(jì)算鏈速確定潤(rùn)滑方式V,z1z20.386ms0.2445725.421141965895mmV--601000601000481925.4(6)計(jì)算壓軸力FpF1000-eV16K1.15K1.15FKF25912980NFPpFpe1.159-3已知主動(dòng)鏈輪轉(zhuǎn)速口,齒數(shù)N,從動(dòng)鏈齒數(shù)8505n218505n21Z299a900mmA [解]由,查表9-1得,鏈型號(hào)16A根據(jù)Flim55.6kWp25.4mmp,查圖9-11得額定功率25.4mm,n850r/ninFCa35kW由查圖9-13得Z21K1.451z且K1AFca3524.14kWKK11.45AZjj第十章齒輪傳動(dòng)習(xí)示的齒輪傳動(dòng)各齒輪所受的力(用受力圖表示各力的作用位置及方向)。IfXX44x23 [解]受力圖如下圖:斗X2主動(dòng)fFrld補(bǔ)充題：如圖(b),已知標(biāo)準(zhǔn)錐齒輪，若中間軸上兩齒輪所受軸向力互相抵消，應(yīng)為mn6,z324PFFa2Ft2tanasin§2Ttanasindm2Ft3tanp玉tanpd33tan3mnZ3cospR2R2m10.5①za2a3,2320,T232TTm10.5①2Rz2tanasin§3sinp即pmnZ3tanasin§sinpm10.5①Rz2cos$ztan§空50z1mnz3tanasin§6240928毗6240928510.50.3289FF2dmm10.5%z2Ft2tanacos富3.765241050.33an30.50810Nsin§0.9280.508kNdFa2Ft2tanasin&3.765103tan200.9281.27210N1.272kN旦學(xué)F3264kNF32玉32cosB2410COS13.2315.408103N5.408kN3gZmnZ363gZ5.408103tan202.022103N2.022kNcos12.321cosB35.889103N35.889103N5.889kNcosFcos20cos12.32110-6設(shè)計(jì)銃床中的一對(duì)圓柱齒輪傳動(dòng)，已知P7.5kW,rb]乙，壽命，小齒輪相對(duì)其軸的支承1450r/min,26,z254Lh12000h為不對(duì)稱布置，并畫出大齒輪的機(jī)構(gòu)圖。 [解](1)選擇齒輪類型、精度等級(jí)、材料②銑床為一般機(jī)器，速度不高，故選用7級(jí)精度(GB10095-88)。選擇小齒輪材料為40Cr(調(diào)質(zhì)),硬度為280HBS大齒輪材料為4540HBS(2)按齒面接觸強(qiáng)度設(shè)計(jì)2.3223KTiU1ZEOH①試選載荷系數(shù)②計(jì)算小齒輪傳遞的力矩95.5105R95.51057.5〒T49397Nmm1n11450d④由表10-6查得材料的彈性影響系數(shù)1Z189.8MPa°Ed鈿2⑥齒數(shù)比全u|42.08⑦計(jì)算應(yīng)力循環(huán)次數(shù)9160n1jLh6014501120001.04410N2.04410Q0.50210QK0.98,K1力vvi°H22)計(jì)算KHN1^Hlim1KHN2lim2S0.98600101d2.3232KTu11①u12KTu11①u1.5493972.081ddmmV-—V601000dn1t1601000bb①dd1t153.57753.577mm④計(jì)算尺寬與齒高之比半htmd1tmth2.25mt2.252.0614.636mmb53.577 ⑤計(jì)算載荷系數(shù)根據(jù)V4.066ms,7級(jí)精度,查圖10-8得動(dòng)載荷系數(shù)K1.2直齒輪，KK1由表10-2查得使用系數(shù)由表10-4用K1.25A插值法查得AK1.420,2KKKKK1.251.211.4202.13AVHH⑥按實(shí)際的載荷系數(shù)校正所算的分度圓直徑ddd60.22t⑦計(jì)算模數(shù)m色浮2.32mmZ261取m2.5⑧幾何尺寸計(jì)算分度圓直徑：d1mz2.52665mmd2m^2.554135mm確定尺寬：ad1d2651352—12—b廠d1U22.0812.52.0812.5189.851.74mm22.08。b52mm,b|57mm(3)按齒根彎曲疲勞強(qiáng)度校核限；大齒輪的彎曲疲勞強(qiáng)度極限FEMPaOFE2。②由圖10-1取彎曲疲勞壽命oKFN10.89,KFN20.93③計(jì)算彎曲疲勞許用應(yīng)力取彎曲疲勞安全系數(shù)S1.417.86MPa0.89500FN1°FE17.86MPaKM牡11S1.4°F2S1.4④計(jì)算載荷系數(shù)孕K252.43K252.43MPaKKKKK1.251.211.372.055AFFYYSa1YFa2YSa2KT bdm bdmFa1Sa112KT 2205549397 2.61.59599.64MPaF1F12.31.71294.61MPa斥 2.31.71294.61MPa斥 210-7某齒輪減速器的斜齒輪圓柱齒輪傳動(dòng)，知n,兩齒輪的齒數(shù)750rmin料為(調(diào)質(zhì))，大齒輪材料為45鋼(調(diào)質(zhì)),38SiMnM。壽命20年(設(shè)每年300工作日),每日兩班制，小齒 [解](1)齒輪材料硬度查表10-1，根據(jù)小齒輪材料為(調(diào)38SiMnM0質(zhì))，小齒輪硬度2仃~269HBS,大齒輪材料為45鋼(調(diào)質(zhì))，大齒輪硬度2仃~255HBS (2)按齒面接觸疲勞硬度計(jì)算T①dT①d￡P(guān)H212Ku1ZZdd1922'①-1.096d1d145.951③由表10-6查得材料的彈性影響系數(shù)—_______________1L,0選取區(qū)域系數(shù)Z189.8MPa2Z2.47EH④由圖10-21d按齒面硬度查得小齒輪的接觸疲勞強(qiáng)度極限P730MPa；大齒輪的接觸疲勞強(qiáng)Hlim,。。⑤齒數(shù)比全u1084.51z1N160n1jLh60750130020288NNI1.28⑦由圖10-19HN11.04,KHN21.HN1取失效概率為，安全系數(shù)1%759.2759.2MPa1S1S1(T1KHN1殆問(wèn)1HmS1P75,e20.88,則eee2Vdm3.14145.957505.729msV601000601000hZh2.25mnt2.25613.5mmh11.85根據(jù)V5.729ms,8級(jí)精度，查圖10-(得動(dòng)載荷系數(shù)K1.22v由表10-3，查得KK1.4得使用110-13得K查得},查得K1.380HB {按dKF卩KKKK1.251.221.41.3802.946AVHd112'T①￡d3d112'2Ku1ZZHE1.0961.63145.9534.5605 22.9464.512.47189.8(3)按彎曲YYFasa丫KKKK1.25AFF0.318①dNtanB12KYB0.3181.0961.332.84024tan922'1.380③由圖10-28查得螺旋角影響系數(shù)當(dāng)量齒數(shù)Z1 cos3B24一亍一cos922'ZvZ2 cos3B108112.3一亍cos922'66.0566.052885986.309Nmm⑤查取齒形系數(shù)及應(yīng)力校正系數(shù)YYFasaYYY1.59Y1.80sa1sa2由圖10-20c查得小齒輪的彎曲疲勞強(qiáng)度極限族；大齒輪的彎曲疲勞強(qiáng)度極430MPa⑦由圖10-1取彎曲疲勞壽命FN10。取彎曲疲勞安全系數(shù)S1.4KFN1SE1°F1S1.50.90430258MPaK%1.5KYYFa305.0773.2366.05YY66.05Fa2Sa2念取%1%266.05YYminYYYYFaSaFa1sa；Fa2sa226T①￡*%1.0961.63145.95226d2KYn1卩YYFaSa(4)齒輪傳動(dòng)的功率即T1284464.096N19.551061284464.0967509.5510611-1試分析圖11-26所示蝸桿傳動(dòng)中各軸的回轉(zhuǎn)方II [解]各軸的回轉(zhuǎn)方向如下圖所示，蝸輪2、4效率，傳動(dòng)比，由電動(dòng)機(jī)驅(qū)動(dòng)，載荷平R5.0kW,nj960/mini23a穩(wěn)。蝸桿材料為20Cr,滲碳淬火，硬度鑄造。蝸桿減速器每日工作8h，要求工作壽命為7年 (每年按300工作日計(jì)) [解](1)選擇蝸桿傳動(dòng)類型根據(jù)GB/T10085-1988的推薦，采用漸開線蝸桿(ZI)。 (2)按齒面接觸疲勞強(qiáng)度進(jìn)行設(shè)計(jì)22LOH貝Upp50826—26—nn2nn22i②確定載荷系數(shù)K1K1A1K1A高，無(wú)沖擊，可取動(dòng)載系數(shù)，則K1.05V曲KKK111.051.05A③確定彈性影響系數(shù)蝸輪為鑄錫磷青銅與ZE鋼蝸桿相配，故④確定接觸系數(shù)Zp假設(shè)魚，從圖11-18中可查得0.35Z2.9p⑤確定許用接觸應(yīng)力MPa應(yīng)力循環(huán)系數(shù)N60n2jLh609601730084.21107召而召而K80.8355HN0則K0.8355268223.914MPaNOH⑥計(jì)算中心距231.059152081602.9160.396mm a200mmi23徑Z2.74ZZppp(3)蝸桿與蝸輪的主要參數(shù)與幾何尺寸；z2Pam825.133*df1d12h；mc60.8mmY1118'36"蝸桿軸向齒厚。S0.5m12.567mma蝸輪齒數(shù)；變位系數(shù)Z247x20.5驗(yàn)算傳動(dòng)比去號(hào)，此時(shí)傳動(dòng)比i23.5Z2i誤差，是允許的。23?5232.17%d2d圓847376mm直ad3762810.5根圓直徑dfd2hf23762810.50.2364.8mmrgadag22-37612mm (4)校核齒根彎曲疲勞強(qiáng)度根據(jù)X2查得齒形系數(shù)YF.22.75Zv47_____Z249.85，從圖11-19中可49.851Y10.9192得由OFFN制造的ZCuSn10P1OF'K560.6636.958MPaOFFN64.21107"3j°59152082.750.919215.48037680.95~0.96tanY(5)驗(yàn)算效率相關(guān)nvarctanfvva4.099ms601000cosY601000cos1118'36‘18中用插值法查得,fv0.0238,代入式得,大于v1.36338121'48"n0.845~0.854v徑向N307/P462073020751301 N307/P4不能承受徑向載荷。接觸球軸承，如圖13-13b所示正裝。軸頸直徑，工作中有中等沖擊，轉(zhuǎn)速d35mmn，已知兩軸承的徑向載荷分別為,1800r^nF“3390N3390NF870Nae確定其工作壽命。 [解](1)求兩軸承的計(jì)算軸向力和FFa,a2對(duì)于a25的角接觸球軸承，按表13-7,軸承a,a2drF0.68FdrF0.68F0.683390d1r12305.2NLh707.2NF0.68F0.68707.2Nd2r2a2maxFd2,Fd1max2305.2,870707.22305.2NFmax707.2,2305.28701435.2N2)求軸承當(dāng)量動(dòng)載荷P12FF0.68e對(duì)軸承1X1Y01對(duì)軸承2X213-6，取，貝fp1.5URfpXFrYFa1339002305.25085N2p2r22a2PfXFYF2p2r22a23)確定軸承壽命，所以按軸承1的受力大小驗(yàn)算P2106C60nR60180035h13-6若將圖13-34a中的兩軸承換為圓錐滾子軸承， [解](1)求兩軸承受到的徑向載荷和將軸系部件FnFr2受到的空間力系分解為鉛垂面(下圖b)和水平面(下圖a)兩個(gè)平面力系。其中：圖c中的為通過(guò)另加轉(zhuǎn)矩而平移到指向軸Fte線；圖a中的亦應(yīng)通過(guò)另加彎矩而平移到Fae作用于軸線上(上訴轉(zhuǎn)化仔圖中均未畫出)。Fte2(F巴JFaenFF廠---ae廠F—FLFeFFr1VF200reFdae2 900200400-乙225.38N0.31250.3125eFF2200846.15NriHte520Fr2Hter1H2200846.15.F2F2rivriH225.38846.152?875.65NF.F2F2r2r2Vr2H21512.62N兩軸承的計(jì)算軸向力查手冊(cè)的30207的e0.37F和F,1.6C54200N-F87273.64N「1FFmaxFd1,FaeFd2max273.64,400472.69872.69Fa2maxFd2,Fd1Faemax472.69,273.64400472.69N3)求軸承當(dāng)量動(dòng)載荷P25472.69F由表13-5查得徑向動(dòng)載荷系數(shù)和軸向動(dòng)載荷系數(shù)為對(duì)軸承1X10.4對(duì)軸承2X12第1.613-6，取，貝fp1.5U1p1r1a1RfXF*F1p1r1a12fpX2Fr2Y2Fa21.511512.620472.692268.93N (4)確定軸承壽命2PP2106C3106542003麗百故所選軸承滿足壽命要LE2^283802342hL'hh13-7某軸的一端支點(diǎn)上原采用6308軸承，其工作可 [解]查手冊(cè)得6308軸承的基本額定動(dòng)載荷查表13-C40800No可99%時(shí)，靠性為190%時(shí)99%時(shí)iaiL0.21o610a6110aC160nP31014080060nP3100.21C60nP1061408003106