TRNG I HC CNG NGHIP THC PHM TP. HCM KHOA C KH NHM :3 GVHD: INH L CAO KSVTH: Trn Minh LanhNguyn vn TriuL vn Hng

Tng quan v b truyn xch1Kt cu xch truyn ngThng s hnh hc b truyn xchng hc b truyn xchng lc hc b truyn xchCc dng hng, ch tiu tnh v chn vt liuTnh ton b truyn xch234567NI DUNG

Tng quan v b truyn xch

Tng quan v b truyn xch

Tng quan v b truyn xch

Nguyn l hot ngB truyn xch thc hin truyn ng t bnh xch ch ng sang bnh xch b ng nh vo s n khp gia rng trn a xch v cc mc xchTng quan v b truyn xch

Nguyn l hot ngCc trc ca b truyn xch c th song song nhau, c th trong b truyn c nhiu bnh xch b dn. Tng quan v b truyn xchbnh xch b dnNgoi ra trong b truyn xch c th c b phn cng xch, b phn che chn v b phn bi trn.

Phn loiTheo cng dng chungXch ko Xch ti Xch truyn ngTheo cu to S dy xch Xch conlnXch ngnh hnh Xch rng Xch nhiu dy Xch mt dy Tng quan v b truyn xch

1.Xch con lnXch rngKt cu xch truyn ng

a xchKt cu xch truyn ng

Xch con ln(1) M trong(2) M ngoi(3) Cht(4) ng(5) Con ln (6) RngKt cu xch truyn ng

Thng thng,s mt xch l s chnThng dng loi xch con ln khi v

Xch ng Cu to ging xch con ln nhng khng c con ln 5, nn b mt rng ca a xch mi mn nhanh. Kt cu xch truyn ngXch ng c dng nhiu hn cCh dng trong cc my n ginLm vic vi tc thpNhng b li khi lng v gi thnh thp hn xch con ln

Xch rngKt cu xch truyn ng

Gm nhiu m xch xp xen k nhau, cc m xch ni vi nhau bng khp bn l. Cc m xch n khp vi bnh xch bi hai mt phng u m xch Kt cu xch truyn ngXch rng

Cc b mt rng lm vic to thnh 1 gc = 60 ,lm vic m, t n C th dng khi vn tc

* a xchKch thc a xch nh, c th dng phi dp. Khi kch thc a xch ln, c th ghp ri may v a xch bng mi ghp hn hay bu lng.Bin dng v kch thc rng xch ph thuc v loi v kch thc xchKt cu xch truyn ng

a xch vi bin dng xch con lnKt cu xch truyn ng

Bnh rng xch iBnh rng xch c gKt cu xch truyn ng

L thng s c bn b truyn xch. Bc xch cng ln th kh nng ti cng cao. ng thi ti trng ng, va p v ting n cng tng theo, nht l khi lm vic vi vn tc cao. Bc xch pc Bc xch c chn theo tiu chun, thng c gi tr t 880,5 mm.Kt cu xch truyn ng

Khng c hin tng trt nh b truyn ai, c th lm vic khi c qu ti t ngt, hiu sut cao. Khng i hi phi cng xch, nn lc tc dng ln trc v nh hn Kch thc b truyn nh hn b truyn ai nu cng cng sut Gc m khng c ngha nh b truyn ai nn c th truyn cho nhiu bnh xch b dnu imu nhc im v phm vi s dng

Bn l xch b mn nn gy ti trng ng, n. C t s truyn tc thi thay i, vn tc tc thi ca xch v bnh b dn thay i. Phi bi trn thng xuyn v phi c bnh iu chnh xch. Mau b mn trong mi trng c nhiu bi hoc bi trn khng tt.Nhc imu nhc im v phm vi s dng

Truyn cng sut v chuyn ng gia trc c khong cch xa, cho nhiu trc ng thi trong trng hp n < 500v/p Cng sut truyn thng thng < 100 kW T s truyn < 6, hiu sut 0,95..0,97Phm vi s dngu nhc im v phm vi s dng

S rng a xch Thng thng Z1 < Z2, nu s rng nh th xch mau b mn (v gc xoay bn l ln) v lm tng ti trng ng cng nh va p. Do , ta hn ch s rng nh nht. Thng thng, khi v>= 2m/s . th zmin >= 19, khi v

S rng a xch nn ly theo s l.tuy nhin trong thc t ngi ta s dng s rng chn.zmax

Thng s hnh hc b truyn xchd. Khong cch trc a v s mt xch x Khong cch trc a c gii hn bi khe h nh nht ca hai a xch t 30..50mm Khong cch trc a v s mt xch xChiu di xch xc nh theo cng thc:Thng s hnh hc b truyn xch

S mt xch X Sau khi tnh s mt xch Cn xc nh li chnh xc khong cch trc aThng gim a mt khong a = (0,0020,004)a to chng cho b truyn xch Thng s hnh hc b truyn xchNn chn X chn

T s truyn trung bnhThng thng xem nhn - s vng quay ca a xch [vng/pht]z - s rng ca a xch - bc xch [mm]Vn tc v t s truyn trung bnhng hc b truyn xch

Xch n khp vi cc rng trn a xch theo hnh a gic nn vn tc xch v t s truyn thay i theo thi gian Xt im A : thay i trong khong (-1/2, 1/2), 1=2/Z1Vn tc v t s truyn tc thing hc b truyn xch

q

v2

v

v1

q

j1

A

v

v

V1

C

B

v1

V V2 = V2 T s truyn tc thi:Do vn tc ca xch v a b dn thay i theo thi gian xch chuyn ng c gia tc gy ti trng ng Khi bn l B vo n khp vi rng a xch ti C, thnh phn vn tc theo phng y ca B l V1, ca C l V1. Hai thnh phn ny ngc hng gy va p gy ting nng hc b truyn xch

Lc tc dng trong b truyn xchF1,F2- lc trn nhnh cng v nhnh chngFt- lc vng: F1-F2=Ftng lc hc b truyn xch

Trong qm Khi lng mt mt xch, kg/mv vn tc vng , m/sF0- lc cng xch ban u bng trng lng ca nhnh xch t dong lc hc b truyn xchFv- lc cng do lc li tm gy nn

qm Khi lng mt mt xch, kg/mg gia tc trng trngKf h s ph thuc vng xchKf = 6 khi xch nm ngangKf = 3 khi xch nm nghing < 400 so vi phng ngangKf = 1 khi xch thng ngng lc hc b truyn xchTrong a chiu di on xch t do bng khong cch trc

V F0 v Fv tng i nh so vi lc vng Ft nn trong tnh ton ta c th ly gn ngLc tc dng ln trc c th xc nh bngVi Km h s trng lng xchKm = 1,15 Khi xch nm ngang hoc nghing < 400Km = 1 Khi xch thng ng hoc nghing >= 400ng lc hc b truyn xch

S thay i c chu k ca vn tc l nguyn nhn thay i t s truyn tc thi, cng l nguyn nhn gy ti trng ng ph trong b truyn.Khi s rng ca a xch cng t th ti trng ng ph sinh ra cng lnTi trng ngng nng va p m khi lng xch tham gia va p.vv vn tc va p.ng lc hc b truyn xch

Cc dng hng, ch tiu tnh v chn vt liuCc dng hng, ch tiu tnhMn bn l, con ln v rng a xchM xch xoay tng i so vi cht v ngMa st gia ng v con ln cng t ti gi tr ti hnHng do miV con ln

Mn bn l Do khi lm vic bn l xoay tng i v chu p sut cao Cc dng hng, ch tiu tnh v chn vt liu

Cc dng hng, ch tiu tnh v chn vt liu Mn bn l Bn l mn lm bc xch tng ln, n khp khng chnh xc hay tut xch Bi trn bn l v hn ch p sut sinh ra trong bn l trnh mn

Hng do mi Do ng sut thay i gy nn ti trng tc ng thay i, ti trng ng v va pCc dng hng, ch tiu tnh v chn vt liu

Vt liuVt liu ch to m xch v a xch phi c bn v bn mn cao, thng ch to t thp carbon trung bnh hay thp hp kim (C45, C50,40Cr, 40CrNi3A). lm vic m hn c th lm a xch t cht do (tectolit,poliamid) , khi vn tc thp (v

Cng xch v bi trn vng cho php ca dy xch t 0,015 n 0,02a. Thng ngi ta cha khong iu chnh l 2 bc xch.Vn tc lm vic n 4m/s bi trn nh k, n 6m/s bi trn nh git, trn 6m/s bi trn lin tc (ngm mt a trong du).Cc dng hng, ch tiu tnh v chn vt liu

Tnh ton xch con ln theo bn mnTnh ton bn mn theo p Trong A = d0 b0 din tch bn l xch 1 dy[p0] p sut cho php theo kt qu thc nghimC th ly gn ng: A=0,28pc2, mm2 Ft- lc vng,NTnh ton b truyn xch

Kx h s xt n s dy xchK h s iu kin s dng xch xc nh theo cng thc sau:Nu x = 1;2;3;4 th tng ng Kx = 1;1,7;2,5;3 Tnh ton b truyn xch

Trong Kr-h s ti trng ngKa-h s xt n nh hng khong cch trcK0-h s xt n nh hng cch b tr b truynKdc-h s xt n nh hng kh nng iu chnh lc cngKb-h s xt n nh hng n iu kin bi trnKlv-h s xt n nh hng ch lm vic.Tnh ton b truyn xch

Ta c cng thc tnh cng sut trn a xch dnTnh ton b truyn xch

[P]-cng sut cho php ca b truyn mt dy c bc pcKz=25/z1-h s xt n nh hng s rng a xchCng sut tnh ton tnh theo cng thcTrong :Pt-cng sut tnh tonTnh ton b truyn xch

Kn=n01/n1-h s vng quay, gi tr n01theo bng tra thc nghimKim nghim xch theo s ln va p trong mt giyX- s mt xch tnh ton theo cng thc Tnh ton b truyn xch

z1,n1 -s rng v s vng quay ca a xch dn;Ngoi ra ta c th kim tra xch theo h s an ton Q- ti trng ph hy cho php ca xch, tra bng;F0- lc cng xch ban u cho trng lng xch;[i] s ln va p cho php ca xch trong mt giy Tnh ton b truyn xch

[s]- h s an ton cho php, ph thuc vo s vng quay v bc xch chon trong bng thng s.F2- lc cng xch trn nhnh chngF1- lc cng xch trn nhnh cng-i vi a xch c ngm trong du ta kim tra a xch theo bn mi tip xc.Tnh ton b truyn xch

Trnh t thit k b truyn xchXch l chi tit c tiu chun ha, thng s u vo cn quan tm P1, n1,u.1-Chn loi xch ph thuc vo cng sut truyn, vn tc v iu kin lm vic.3- Tnh s rng a xch ln theo z2=uz1 vi iu kin z2

4- Xc nh cc h s iu kin s dng xch K theo5- Tnh cng sut tnh ton Pt theoChn bc xch pc tiu chun theo bng 5.4 (gt)6- Kim tra s vng quay ti hn theo bng 5.2 (gt)Tnh ton b truyn xch

7- Xc nh vn tc ca xch theo v lc vng c ch Ft8- Tnh ton kim nghim bc xch Tnh ton b truyn xch

9- Chn khong cch trc s bS mt xch theo cng thcTnh chnh xc khong cch trc theo Tnh ton b truyn xch

10- Kim tra xch theo h an ton theo cng thcKim tra s ln va p ca xch trong mt giy theo cng thc11- Tnh lc tc dng ln trc theo cng thcTnh ton b truyn xch

1. So vi b truyn ai c cng cng sut & s vng quay, b truyn xch c kch thc:a. nh hnb. ln hnc. bng.d. khng so snh c.20191817161514131211109876543210Cu hi n tp

2. Khi gp qu ti t ngt, b truyn no cn c th lm vic c?a. aib. xch.c. rng.d. b&c.20191817161514131211109876543210Cu hi n tp

3. S phn b cc nhnh xch trn a xch theo:a. ng trn.b. lc gic.c. tam gic.d. a gic.20191817161514131211109876543210Cu hi n tp

4. Khi vo & ra khp, cc mt xch xoay tng i vi nhau dn n cc hin tng:a. bn l xch b mn, gy ti trng ng ph & chuyn ng b truyn m i hn.b. gy n khi b truyn lm vic, mn bn l xch & tng ti trng ng ph.c. gy hin tng trt tc thi, gim n & tng ti trng ng phd. tt c u ng 20191817161514131211109876543210Cu hi n tp

5. Vi xch c s mt chn, ta s dng b phn g ni xch li vi nhau?a. kho.b. m xcch ngoi.c. cht bn l.d. tt c u ng.20191817161514131211109876543210Cu hi n tp

6. Xch ng khc xch con ln im:a. khng c cht.b. khng c con ln.c. khng c m ngoi.d. khng c m trong.20191817161514131211109876543210Cu hi n tp

7. So vi xch con ln, xch rng c th:a. truyn ti trng thp hn vi vn tc lm vic nh hn.b. truyn ti trng cao hn vi vn tc lm vic nh hn.c. truyn ti trng cao hn vi vn tc lm vic ln hn.d. truyn ti trng thp hn vi vn tc lm vic ln hn.20191817161514131211109876543210Cu hi n tp

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