I, R2=LR 4, Nhu v~y mQt cau can bang la cau co:
cllllyci! I'! nia chi 116 hi dan
trtIdc khi h~ xuang voi cling tac dQ trang eung thai gian. Cam c6 dinh nhQn (hlnh 2.32c) eho phep chi tiet bi dan C1 tr~ng thai tlnh khi cam quay dtIQ'c khoang nlea vong (ben ban hnh co djnh) , sau do tien va lui doi xling tren khOliog 1/4 vong chuyen dOng can l<;li. Lo~i cam nay thmmg duqc Slr dy.ng de kiem sout van d(mg ca, khoang ngirng lit khoang thai gian de hon hQ'p xang dau ho~e khi di vao xilanh. Thai gian tn~ cang dai tlll1I1g ling voi chieu diti he m~t cam co ban kinh co dinh Ion hon cho phcp xilanh co du thai gian
d6
n'.lp khi d~ ehay.Cac chi tiet b! cam dan cOng co nhiing ki~u khac nhau. Lo~i can Ian (ban chat ia goi Ian), co uu di~m la t~o rna sat t~i di~m tiep XllC, rna sal quay nha hem nhifu so vai rna sat tfUqt, tuy nhicn li;li dat hem. Chi tie't b! dan co m~t ticp xuc phfmg duqc su dl:mg kh<i ph6 bien vl gia
re
va co tht duqc che t<;to nha hem can Ian.Kct diu cam duqc Slt dl]ng nhi~u trong che t~o may, cung vai canh tay don va tfl]C khuyu t~o nen cac chuoi dQng hQc trong cac may cong cl,l chep hlnh c6
d~ri~n~~~~diq~~~cic~c~a~~_2.3
tht hi¢n mOt
s6
gii'ti phap vf co cau dan dQng cam va m6i quan h~ ve chuyen dQng, momen, il]'c giUa cac phan tu clla co cau.Bang 2.3: Mqt s6 cO cau dan dqng bang cam
Cocau Ki hieu M6i quan h~ ham
Cam-dn tinh tien (Inrot) . .
"
0
x,=f('( '1',), '1',)~ ...
F,=/(r( '1',), '1'" T,)r(<{l,) ... ~ ~
.,
Cam -can hic
'2 •
0
'I',=f(,( '1',), '1',)'(.')~ n.
T,=f(,( '1',), 'I'1,T,)T, ,)).,
Cam -can Jac kh6ng gian (quay)
'I',=f(h( '1',), '1',)
0
T,=f(h( '1',), 'I'"T,)~2 n.
T, T2 .,~- hi'l'l}MQi kf hi~u trong bang 2.2 co cung
y
nghla nhu bang 2.3, v6'i d~i ltrqng It la chuy~n vi cua cd cau bi dan.2.4.1.5. Truycn dqng banh rang
Rinh rang ia Cd cau duqc Slt <.h;mg fat ph6 bien d~ truy~n ehuyen d9ng quay tfon. Chung duqe sii dl]ng khi can thay d6i toe dQ ho~c momen quay eua thiet
bi. Vi d!,l. h(lp
s6
cua xc 0(6 cho phcp biinh dfin c6 (OC dQ va mOrnen quay theoyeu du clIa dia hinh vo; nang 1l1(,1ng cua dQng ca duqc lrang bi.
Clluyen dOng quay co the duqc truyen tii m¢1 lr1,lC sang lr!,lc kh:k qua c~p
biinh Ir!,l quay nho rna
sal
ti€p xuc. Tuy nhien Iruyen d¢ng kieu nay co nhieu khlinang sinh lruqt In~n
be
rn~t tiep xue. Hi¢u sua"1 lruyen se duqc nang eao neub6
sung 1\n kh6'p n1ng clla hai m~1 In,! va do la co ca'u an kh6p banh r:lng (hinh
2.33).
a) Imyln dqng hm tn.le
song song: banI! m., rang IIghiellg
