4.1 . Ca'u t�o
Role toe d9 d- c;,c dung nhieu nhat trong m9ch di$n ham ng- c;,c cua cac d9ng co khong dong b9, nguyen ly cau t9o nh- hinh ve.
Hlnh 4. 1 0: Nguyen ly cau t�w rdle toe d9 PKC
1. Tn,ic Rdle
2. Nam cham vTnh cuu 3. Ong tr1,1 quay tl/ do. 3. Ong tr1,1 quay tl/ do. 4. Thanh dan 4. 5. Can day.
�} H� thong tiep di�m 8.} Thanh thep dan hoi 9.
10. Tiep di�m
Tr1,.1c 1 cua role toe d9 d- <;jc noi dong tr1,.1c vdi roto cua d9ng co hO?C vdi may can khong che. Tren trvc 1 c6 lap nam cham vinh cll'U 2 lam bang h<;jp kim Fe - Ni c6 d9ng hinh trv tron. Ben ngoai nam cham c6 trv quay ti/ do 3 lam bang nhG'ng la thep mong ghep 19i,
m?t trong trv c6 xe ranh va d?t cac thanh dan 4 ghep m9ch voi nhau giong nh- roto long s6c. Trv nay d- c;,c quay ti/ do, tren trv c6 lap tiep di�m d9ng 10.
4.2. Nguyen ly lam vi�c:
Khi d9ng co di$n ho?c may quay, trvc 1 quay theo lam quay nam cham 2, tu' tr-ang nam cham cat thanh dan 4 cam Ctng ra sCtc di$n d9ng va dong di$n cam Ctng cJ long s6c, sinh ra momen lam trv 3 quay theo chieu quay cua d9ng co ... Khi trv 3 quay, can d�y 5 tuy
theo h- cJng quay cua rota d9ng co di$n ma dong (ho�c md ) h$ thong tiep diem 6 va 7 thong qua thanh thep dan hoi 8 va 9.
Khi toe d9 d9ng co giam xuong gan bang khong, sCrc di$n d9ng cam Crng giam tcJi mCrc lam momen khong du de can 5 day d- <;Jc cac thanh thep 8 va 9 nG'a. H$ thong tiep diem trd ve vi trf b1nh th- bng.
4.3. Hu hong va cac nguyen nhan gay hu hong:
Khi s\J d1,mg rdle toe d9 ta th- dng g�p nhCtng h- hong sau. + H- hong cac tiep diem.
- Ltjc ep tren cac tiep diem khong du.
- Gia da tiep diem khong bang ph�ng, cong, veng.
- Be m�t tiep diem bi oxy h6a do xam thljc cua moi tr- dng lam vi$c ( c6 h6a chat,
A?
Ht ) am - v vv .. . . am - v vv .. . .
- Do h�u qua cua vi$c xuat hi$n dong di$n ngan m9ch m9t pha vdi "dat" ho�c dong ngan m9ch hai pha a phfa sau rdle ...
+ H- hong thanh thep dan hoi 8 va 9.
- Do thanh thep bi mat tfnh dan hoi (moi ccJ h9c). - Do ngo9i ltJc tac d9ng vao.
+ Nam cham vinh c\Ju mat tu' tfnh do lam vi$c trong cac moi tr- bng khU' tu'.
+ H- hong cac ong tr1,1 quay tlj do. Do cac be m�t tiep xuc khong tot, do b1,1i ban ...
4.4. SU'a chu'.a role
• Bifn phap su'.a chua :
- Ltja ch9n rdle phai dung dong di$n, di$n ap va cac che d9 lam vi$c t- dng Crng. - Kiem tra va s\Ja chG'a nan th�ng, ph�ng gia da tiep diem, dieu ch1nh sao cha trung khe1p hoan toan cac tiep diem d(mg va tinh cua rdle.
- Kiem tra 19i d9 dan hoi cua thanh thep dan hoi 8 va 9 de dam baa ltjc ep tiep diem - Kiem tra va baa d- ang cac ong tr1,1 quay tlj do.
- Kiem tra tu' tfnh cua nam cham vinh c\JU.