P h m g phip đng dang 1 i p h m g phhp dun giin nhilt, dqa vio cic bum m5u
c6 san hogc chc bum md hinh c6n, Mcmg tq. Theo phuung phip nhy ngudi ta chi
viec nhan cdc'kich thudc cda bum thuc vh bum miụ D& tinh to6n the0 phrrmg phip
dH ntu ngulti ta phHi c6 bin thibt kb chudn cha born m b hoQc bum rn6 hinh, dgc
tinh nang lumg cfia bum d& dua vio d 6 x5c djnh he s6 chuygn đị Trong t n h g h* kh0ng c6 b i n thiQ k& chudn thi r6 rang 18 bHn thibt kb mdi sB kh6ng dat y&u
c h v& th6ng si5 nang luqng ciing nhu hi@ sugt clia bum.
CAc kich thubc ca bin c8a binh c0ng tic xac djnh theo phucmg tr'hh d6ng dang :
f i
C = K , X--
n (3.26)
He st5 tf 1e 88ng dang the0 bum m6 hinh:
6) P h m g phiip mot @ad@
Phucmg phap mot toa do lh phuung phip thi& kk d m gi%n h u n g c6 hi@ qui, pr6fin cinh thi&'t k$' dim b i o g6c vio vh g6c ra cfia cinh phti h* vdi dgc tinh dbng chiy, phuung phip niy duuc sir dung rong rCị Khi sir dung phuung phip niy dbi
hbi ngu& thikt kk phii c6 kinh nghiern trong viec lua chon m0t s6 thbng s6 hinh hoc ban d$u c i a ludi cinh. Them vho 66, vi&c thi& k&'ludi cinh chi c6 thd thuc hien bing ph6p d ~hinh th6 c6ng g kh6 lap trinh tinh toen tr&n m i y vi tinh.
Phumg phhp Iuc nang lj. phumg phPp d q c sir dung r6ng riii b c6c nudc TAy
Au, nhu ta dB biB, binh c6ng tPc duuc tinh to6n bang phumg phPp hai toa do tirc lh bhnh cdng t6c phii tinh tohn cho mQt so" tigt dicn tir bdu c h h tdi vb bum, thuc tE
m6i ti& dien lh mgt prdfin, chc prbfin tumg h g vdi m6i tiEt dien khac nhau sE c6
cAc he so" luc nang khdc nhau, n6u chon prbfin khi dbng thoi miin chc he s6 luc nang vA luc chn tbi uu thi cdc ti& dien sE c6 c6c prbfin dang khPc nhaụ Nhu v+y
khi xAu c6nh sE kh6 d%m bAo su subn deu cha 16 chnh. Chinh vi vgy, trong qu6 tr'hh thigt kk phAi vE vB di$u chinh cAc thdng s6 n h i h Ian tao ra kh6 khan cho vi&c lap trinh v i tlnh tohn trkn may vi tinh. Phumg ph5p nay c6 uu diem lh khdi Iuqng tinh to6n d m giIn vh sir dung cLc prdfin khi dong dii dude khio nghiem tin cay, hi+ sugt cao; phuuqg phLp nPy sir dung cho thigt kk b a n c6 sB l i c6nh Z nhb, viec xAc dlnh cac thbng s 6 pr6fin d m vdi pr6fin d5y cdnh rgt kh6 kh8n.
Phumg phdp X m Z dua trkn giA thuygt 118 do cong c6a d u h g nhan prdfin c6 anh hdmg quygt d m tdi luu s6 v+n t6c hay do cinh tao nen, vi v+y, ciing Anh h ~ h g quye"t djnh tdi lgc nang tic dung 1Cn prdfin cinh. Dqa theo quan h& cha lgc nangC,, vdi l m s 6 v+n t6c bao quanh prdfin vP quan he c6a lqc nAngC, vdi g6c dac tnmg cho 66 cong c i a prdfinp, ta xLc d~ dudc ggcp, theo c i c th&ng sB hinh hoc v i dong hoc cha ciinh. Trong tntirng h* nhy d ~ h g nhhn cha prbfin 1P mot cung trbn.
e ) Phu;mg phhp Bauerospheldo
Gia thi&'t t h h h phAn quay cua vgn t6c vbng cfia xoiiy Litn h* bi triet tiCu
w , = 0 . Phuang phiip nPy d ~ g c sir dung rong r l i dB tinh toin thi& kC bAnh c8ng thc barn ly tarn ty t6c caọ barn ly tarn ty t6c caọ
Dqng d u h g dong thg trong ti& dien kinh tuygn cfia bAnh c6ng tic SE d ~ g c
d u h g dong S, c i c d ~ b n g deng thbo vh tntbng v+n tbc V , .
Theo diZu ki&n song song c6a vkc-ta xoLy be mat l i c5nh F ta c6:
Ti& dien kinh tuyen be mgt l i c h h F m t r h g v6i cic d u h g xoiy thinh phinọ. Nghia lA, vdi c l c d ~ h g e ~ .r = consr n h tr&n mgt phi!ing kinh tuygn, & mat bang sE la cac d u h g thang.
Cho quy luat thay đi V, .R = f (6)d6i vdi mot trong chc d u h g dbng vdi gi9 trl
V m , ta c6 th& xay d q g dude b& mat li cinh nhd phumg tr'hh vi phan c3a d u h g cat
lii c h h vdi b& mat d u h g dbng:
GiH si3 qui lust V , R = f ( 8 ) n h ~ nhau d8i viri tgt cA chc d ~ h g dbng. Phumg trinh d u h g dbng duuc tich phan the0 hhm dB cho doc the0 chc d u h g dbng:
Trong thqc te, ttich phan nBy thubng d ~ g c cho d ~ d i dang bing.
fl Phumg phbp Vdzmhexenski - Pkkin vu LkxGkhin- Sim8n6v
CBc phumg ph6p tinh to6n cha Vbzonhexenski-P&kin v i Uxdkhin-SimBnBv c6 noi dung co bAn gi6ng nhau, the0 c6c ph~cmg ph5p nay t5c dong c6a cdc profin l&.n dbng chgt llbng d ~ u c thay thg bbi c5c xo5y phan b6 doc d u h g nhan theo mgt quy lust xhc d m . Dbng chiy tBng hqp duqc x5c d w bang tBng ciia dbng song phhng khong n h i h va dbng xo6y tao bhi c6c xoiy phan bB theo dulmg nhan ciia profin, bang c9ch x6c dinh d ~ b n g dbng d n g hgp nhy sE x i c d j n h ' d ~ l m ~ n h w cha prbfin, d6 ciing la profin c9nh c6 chi& day m6ng vB ciing. DQ xic djnh profin c6 chi& dhy h i h han ta d$ do day tr&n d u h g nhAn profin the0 mQt quy lust xic dinh, bang chch chon c6c prdfin thuc nghitm c6 dac tinh khi dQng t6t rdi My quy lugt phan bB d e d l y cSa n6 d& lam mhu chudn cho prBfin thi&t k& mdị
Di&u kh5c nhau chinh giila hai phumg phAp Ih: theo phumg phap Vbzunhexenski - P&kin coi dubng nhdn la mot cung trbn khi 66 c6 th6 giii dudc phuang trlnh tich phan h i m dhng cha d u h g dbng tao b&i dbng song p h h g khbng n h i h vA dbng xoiy tao bbi cAc xoiy lien hap phdn bd tren dubng nhdn cha t$t cci cac prbfin trong ludị Cbn theo phumg phhp LBxBkhin - SimBnBv d u h g nhdn cha prbfin la mot cung cong bai kp x i c d@ bhi dbng song p h h g khbng nhi&u vh cic xoiy phan bb tren d u h g nhan c3a t$t cA c6c profin. T&g hap nay khbng thd giHi
gdn dling lien ti&p. W v+y, vi&c giAi phucmg tr'inh tich phan sE rgt ph3c tap, nhung
dip lai, ph-g ph8p nhy cho c i c k&t q u i phG hop hun vdi bin chgt dbng chiỵ 3.2. Tinh toan thiét ke" may b m dbng chko
3.2.1. Cuc yku cdu ky thuut tir thqc le"'
Thqc t6 sin xu& ir cfic vCing s h xu& nbng nghi&p c6 su dao dong 1611 v& mcc n ~ d c b6 hht tram barn dbi h6i phii c6 m8y bum nudc thi& kgblrn bio H 3 10m. Ve
m9y b m , c6 th6 d8u ttu nghien c h , thigt kg, chg tao c9c m9y b m dbng ch6o v& he s6 tf t6c cnS = 469v / ph , cbng sugt dong caN = 37KW , cat 6p H r 1 Om, h.m luwg
Q = 900 m 3 / h .
3.2.2. Tin h toun cac thdng s 8 kj thuat ctr bdn bun h c6ng fric b m d6ng chko
Sq phAt tridn c6a khoa ha, cdng nghe ciing nhu cAc nhu cAu c6a sAn x u 8 đi hoi su cdn thigt phii nang cao do b$n vii hi@ qu6 kinh tE cha c i c miiy bum, trong