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Slide 1
Chng 5: TRUYN NG BNH RNG
1. Khi nim chung2. Ti trng trong truyn ng bnh rng3. Cc dng hng v ch tiu tnh b truyn bnh rng4. Tnh ton b truyn bnh rng tr5. Truyn ng bnh rng cn rng thng6. Vt liu , nhit luyn v ng sut cho php7. Trnh t thit k b truyn bnh rng
11. KHI NIM CHUNG
1. KHI NIM CHUNG
1. KHI NIM CHUNG
1. KHI NIM CHUNG
Bnh rng trBnh rng cnBnh rng tr cho1. KHI NIM CHUNG1.1. PHN LOI, U NHC IM * Phn loi:- Phn loi theo v tr cc trc- Phn loi theo s phn b cc rng
n khp ngoin khp trong1. KHI NIM CHUNG- Phn loi theo phng rng so vi ng sinh
Rng thngRng nghingrng congrng ch V1. KHI NIM CHUNG81. KHI NIM CHUNG- Theo tnh cht di ng ca cc tm b truyn:+ Truyn ng bnh thng: cc tm cc bnh rng c c nh.+ Truyn ng hnh tinh: tm ca mt hoc nhiu bnh rng di ng.
1. KHI NIM CHUNG- Theo phng ca rng (so vi cc ng sinh):- B truyn rng thng (bnh tr rng thng, bnh cn rng thng).- B truyn rng nghing (bnh tr rng nghing, bnh cn rng cong).
Nghing phiNghing triTheo hnh dng rng:- Truyn ng bnh rng thn khai.- Truyn ng bnh rng xiclit- Truyn ng bnh rng Nvikov.
1. KHI NIM CHUNG
1. KHI NIM CHUNG* u im:- Kch thc nh, kh nng ti ln.- T s truyn khng thay i.- Hiu sut cao, c th t 0,97 - 0,99.- Tui th cao, lm vic tin cy.* Nhc im:- Ch to tng i phc tp.- i hi chnh xc cao.* Phm vi s dng:Truyn ng bnh rng c dng rt nhiu trong cc my, t ng h eo tay, kh c cho n cc my hng nng, cng sut truyn t nh n ln (300MW), vn tc c th t thp n rt cao (200m/s).
1. KHI NIM CHUNG1.2. Cc thng s hnh hc ch yu ca b truyn bnh rng tr- Bc rng: - M un:- ng knh vng ln: - ng knh nh rng:- ng knh chn rng:- Gc n khp: - Chiu di rng: - Khong cch tm hai bnh rng:
1. KHI NIM CHUNG1.3. chnh xc ca b truyn bnh rng- Kh nng lm vic ca b truyn bnh rng ph thuc nhiu vo chnh xc ch to bnh rng. Nhng sai s ch to lm sai lch hnh dng prfin v phng ca rng, gy nn sai s bc rng, to ra khng song song gia cc trc bnh rng Kt qu l t s truyn thay i, gy nn ti trng ng ph, rung ng v tng thm ting n. Nhng sai s trong ch to cng lm xut hin s tp trung ti trng trn rng.- Bnh rng c kim tra theo cc yu t chiu dy rng, bc rng, o hng tm ca vnh rng, hnh dng thn khai ca mt rng v.v v kim tra theo cc ch tiu tng hp nh chnh xc ng hc, lm vic m, s tip xc cc rng v khe h cnh rng khi n khp.- Cp chnh xc c chn theo ch tiu chnh xc ng hc, lm vic m v tip xc cc rng.2. TI TRNG TRONG TRUYN NG BNH RNG2.1. Lc tc dng ln cc rng khi n khp
2. TI TRNG TRONG TRUYN NG BNH RNG2. TI TRNG TRONG TRUYN NG BNH RNGB qua lc ma st, lc phn b trn chiu di rng c thay bng lc tp trung t ti im gia ca vnh rng. c phn lm ba thnh phn:- Lc vng:- Lc hng tm: - Lc dc trc: T - m men xon tc dng ln bnh rng ang xt- gc n khp trong mt ct php tuynTrng hp: Vi b truyn bnh rng thng:
2. TI TRNG TRONG TRUYN NG BNH RNG2.2. S phn b khng u ti trng trong b truyn bnh rng* S phn b ti trng gia cc rng: khi , do sai s ch to, dn n s phn b khng u ti trng gia cc i rng n khp. Khi tnh ton theo ng sut tip xc c c trng bi , khi tnh theo ng sut un c c trng bi .- i vi b truyn bnh rng tr hoc cn c rng thng ly: - i vi cc b truyn c rng nghing: - c tra theo cp chnh xc v vn tc vng v. Khi tnh ton s b c th ly - c xc nh theo Khi ly Khi xc nh theo biu thc ( cp chnh xc ca b truyn theo ch tiu tip xc; khi ly )ly
2. TI TRNG TRONG TRUYN NG BNH RNGS phn b ti trng theo chiu rng vnh rng(chiu di rng)Nguyn nhn: do rng b bin dng, trc v vnh rng b bin dng xon, trc b un.Khi tnh ton theo bn tip xc: - Trc chy mi c c trng bi h s- Sau khi chy mi c c trng biTrong : - cng ti trng ln nht. - cng ti trng ln nht sau thi gian chy mn. - cng ti trng trung bnh.Khi tnh ton theo sc bn un c c trng bi , i lng ny c tra bng ph thuc vo h s
2. TI TRNG TRONG TRUYN NG BNH RNG2.3. Ti trng ng khi n khpDo bin dng ca rng v nhng sai s bc rng, prfin rng, t s truyn tc thi thay i, gy nn ti trng ng khi n khp. Khi tnh theo bn tip xc c c trng bi , khi tnh theo bn un c c trng bi .Vi b truyn bnh tr: trong :
Vi b truyn bnh rng nn c tnh tng t, ch thay v
3. CC DNG HNG V CH TIU TNH B TRUYN BNH RNG3.1. Cc dng hng:Gy rng: do ng sut un gy nn, xy ra vi nhng b truyn h.Trc v mi b mt: do ng sut tip xc, xy ra vi b truyn kn.Mn rng: do ma st.Dnh rng: khi lm vic vi vn tc v cng sut ln.Bin dng do b mt rng: xy ra nhng cp bnh rng c rn thp.Bong b mt rng: xy ra cc rng c thm Nit, thm Ccbon hoc ti b mt, trong trng hp cht lng b mt khng tt v rng chu ti trng qu ln.3.2. Ch tiu tnh:Vi nhng b truyn h, khng c bi trn tt, tnh theo iu kin sc bn un.Vi nhng b truyn lm vic kn, c ngm du, tnh theo sc bn tip xc.
4. TNH TON BN B TRUYN BNH TR4.1. Tnh b truyn bnh rng tr rng thng theo bn tip xc.ng sut tip xc c tnh theo cng thc:ZM: H s xt n c tnh ca vt liuZH: H s xt n hnh dng b mt tip xcZ: H s xt n tng chiu di tip xcKH: H s tp trung ti trngKHv: H s ti trng ng khi tnh bn tip xc.
4. TNH TON BN B TRUYN BNH TR4.2. Tnh b truyn bnh rng tr rng thng theo bn unB qua nh hng ca lc ma st, qua bin i ta c ng sut un ti tit din nguy him chn rng c tnh theo biu thc:
Khi kim tra bn un, phi kim tra cho c hai bnh rng:
Khi thit k, tnh m un theo cng thc:
4. TNH TON BN B TRUYN BNH TR4.3. Tnh b truyn bnh rng nghing theo bn tip xcCng thc kim nghim bn tip xc ca b truyn bnh rng tr, rng nghing hoc rng ch V c dng:
Khi thit k b truyn, c th tnh ng knh bnh rng nh hoc khong cch tm hai bnh rng theo cng thc:
Sau tnh m uyn theo cng thc:
4. TNH TON BN B TRUYN BNH TR4.4. Tnh rng nghing theo bn unng sut un trong rng nghing c xc nh:
Khi thit k, tnh m un theo cng thc:
- c ly theo bnh rng no c tr s nh hn.
4. TNH TON BN B TRUYN BNH TR4.5. Kim nghim bn ca rng khi qu tiTrng hp b truyn bnh rng khi lm vic b qu ti t ngt trong thi gian ngn, cn tin hnh kim nghim bn b mt rng v bn ca rng trnh bin dng d b mt hoc b mt b ph hng v gin cn bo m iu kin:
trnh gy rng v gin hoc bin dng d do un cn phi m bo iu kin:
5. TRUYN NG BNH RNG CN RNG THNG 5.1. Khi nim chung- Dng truyn chuyn ng gia cc trc ct nhau mt gc no , thng l gc vung.- t dng truyn ng bnh rng cn c trc khng vung gc v cng ngh ch to v lp ghp phc tp. - So vi truyn ng bnh rng tr, truyn ng bnh rng cn c kch thc v khi lng ln hn, ch to phc tp hn v lp ghp i hi kh chnh xc theo phng dc trc. - Tuy nhin truyn ng bnh rng cn vn c dng nhiu trong cc my v kh c v iu kin b tr c cu i hi phi s dng b truyn c cc trc ct nhau.- Truyn ng bnh rng cn c cc loi rng thng, rng nghing, rng cung trn, rng cong (thng s dng rng thng v rng cung trn).
5. TRUYN NG BNH RNG CN RNG THNG 5.2. Cc thng s hnh hc ch yuGc mt cn chia (mt cn ln) ca bnh nh v ca bnh ln.
Vng trn chia ngoi : Vng trn chia trung bnh: T s truyn: Mun vng ngoi (c quy chun) v m un vng trung bnh: Chiu di cn ngoi:B truyn bnh rng cn thng c dch chnh u (h s dch chnh chn ) nng cao bn un ca bnh rng cn nh ( )
5. TRUYN NG BNH RNG CN RNG THNG 5.3. Lc tc dng trong b truyn bnh rng cnTrong tnh ton b qua lc ma st ta c cc thnh phn lc tip tuyn, lc hng tm v lc dc trc tc dng ln mi bnh rng c xc nh nh sau:
Trong :
5. TRUYN NG BNH RNG CN RNG THNG 5.4. Tnh ton bn b truyn bnh rng cn5.4.1. Tnh theo bn tip xcCng thc kim nghim bn tip xc ca b truyn bnh rng cn rng thng:
Khi thit k b truyn bnh rng cn bng thp, ng knh vng chia trung bnh ca bnh cn rng thng xc nh theo cng thc:
Thng ly v phi m bo iu kin
5. TRUYN NG BNH RNG CN RNG THNG 5.4.2. Tnh theo bn unng sut un ca b truyn bnh rng cn, rng thng:
5.4.3. Kim nghim bn ca rng khi qu tiTrng hp b truyn bnh rng khi lm vic b qu ti t ngt trong thi gian ngn, cn tin hnh kim nghim bn b mt rng v bn ca rng. Cch tnh ton kim nghim c tin hnh tng t nh i vi b truyn bnh rng tr
6. VT LIU, NHIT LUYN BNH RNG V NG SUT CHO PHP6.1. Vt liu v nhit luyn bnh rngVt liu ch to bnh rng phi tho mn cc yu cu v bn b mt (trnh trc r, mi mn, dnh) v bn un. - Bnh rng bng vt liu khng kim loi: khi lng nh, khng b g, lm vic khng n. Nhng bn khng cao, kch thc tng i ln v gi thnh ch to cao.- Bnh rng bng gang: r hn bnh rng bng thp, c dng trong cc b truyn lc h chu ti nh.- Bnh rng bng thp: c dng ph bin trong cc b truyn lc.Tu theo rn (hoc cch nhit luyn) c th chia bnh rng thp ra lm hai nhm chnh:Bnh rng c rn HB 350: bnh rng thng ho hoc ti ci thin.Bnh rng c rn HB > 350: bnh rng ti, thm than, thm nit hoc thm xianua.
6. VT LIU, NHIT LUYN BNH RNG V NG SUT CHO PHP6.2. ng sut tip xc cho phpng sut cho php khi tnh theo bn mi tip xc:
Trong cc bc tnh s b c th lyTrong : - Gii hn bn mi tip xc - H s nh hng ca s chu k lm vic Vi bnh rng thng, ng sut cho php l gi tr nh hn trong hai gi tr.Vi bnh rng nghing:
ng sut tip xc cho php khi qu ti:
Bnh rng trBnh rng cn
Vi br thng ha, ti ci thin hoc ti th tchVi br ti b mt, thm C, thm N6. VT LIU, NHIT LUYN BNH RNG V NG SUT CHO PHP6.3. ng sut un cho php
Gii hn bn mi un H s an ton ph thuc cng ngh ch to phi v cc yu cu i vi b truyn.ng sut un cho php khi qu ti:
Khi HB 350- Khi HB > 3507. TRNH T THIT K B TRUYN BNH RNG1- Chn vt liu bnh rng, phng php nhit luyn, tra c tnh ca vt liu: gii hn bn, gii hn chy, rn ca rng.2- Xc nh ng sut cho php.3- Tnh s b ng knh vng ln bnh nh theo iu kin v bn tip xc (i vi b truyn kn, dng hng v trc r nguy him hn c). 4- Tnh khong cch trc s b theo tr s v t s truyn u. nh mun m ca b truyn, ly theo tiu chun, (i vi b truyn bnh rng nghing m l mun php).5- Chn s b gc nghing , tnh s rng v tnh li gc nghing theo s rng c quy chun.6- Tnh li kch thc ng knh v khong cch trc theo s rng, mun v gc nghing (i vi b truyn bnh rng nghing). nh chiu rng vnh rng v kim nghim iu kin h s trng khp dc.7- Kim nghim rng v bn tip xc.8- Kim nghim rng v bn un.9- Kim nghim bn ca rng khi qu ti (trng hp b truyn chu qu ti t ngt).10- Xc nh cc kch thc ch yu ca b truyn.