- Bao tri, bao duong duqc may nen khf va thiSt bi phan ph6i khf nen.
A- BJ mfjt lam Vi?C cua piston (cm 2)
P - Ap sua't cung cap (kPa, 105 N/m2, bar/14,5 psi)
□ - Hi?U suit
Trang thl/c te c6 nhang sai s6 thuang tha'y so vai nhang fl/c dJy th?t. EJ€ xac djnh /Lfc dJy th?t cJn tfnh den nhang sai s6 nh?n duqc do sue can ma sat. Trang nhang diJu ki¢n lam vi?c btnh thuang (vung ap sua't 400 - 800 kPa/ 4-8 bar), nguai ta c6 th€ gia djnh /Lfc ma sat khoang bling 3-20% /Lfc ly thuyet.
Llfc diy thl/c te duqc tfnh nhu sau:
• Xy lanh tac d9ng dan Fn = A . P - (Fr + Fr)
• Xy lanh tac d9ng kep
- CJ hanh tr,nh thu?n: Fn = A . P - Fr
- CJ hanh tr,nh nghjch : Fn =A'. P - Fr
Trang d6: Fn - Ll/c dJy thl/c te (N)
A - BJ mfjt lam Vi?C cua piston (cm2)
2
A=nxD
4
A' - BJ mfjt lam vi?c cua piston, phfa c6 cJn piston (cm2)
P - Ap sua't cung cffp (kPa, 105 N/m2 , bar/14,5 psi) nx(D2 -d2)
A = - - - -
4
FR - Ll/c ma sat, bling 3 - 20% Frh (N)
FF - LLjc phan h6i cua lo XO (N) D - Duong kfnh cua xy lanh (cm) d - Duong kfnh cua cJn piston (cm)
-EJQ dai cua hanh tr,nh
EJ9 dai hanh tr1nh cua m9t xy lanh khf nen thuang khong vuqt qua 2000 mm. Khi hanh tr1nh qua dai, duang kfnh xy lanh qua Jan th, vi?c ung dvng khf nen la khong kinh te.
Khi hanh tr1nh vuqt qua mQt gfa tri giai h9n nha't djnh, d9 moi ca hoc cua trvc piston va cua b9c se giam. EJ€ tranh ta't ca nhang nguy ca u6n doc, nguai ta tang
duang kfnh cua cJn piston fen khi hanh trlnh dai, hem nua Sl/ keo dai cua hanh trlnh lam tang them khoang each giua cac ci'ta va nha d6 cai thi¢n tfnh d.in huang cua cJn.