Question

The figure shows a gear-driven squeeze roll that is used to produce laminated wood product. The rolls are designed to exert a normal force of 5000N/m, and a pull of 4000 N/m on the material. The roll speed is 500 rpm. Please design the hydrodynamic bearing at location A. (30%) Į I 374 140 mm I 200 mm 40 mm L70 mm Į Î Î Î Powered roll, 100 mm diameter Î Idler roll- Î Gear 75 mm diameter E

Answer 1

r Bearing lune of centre Jounel sho

sop. Braing Jo00 NIm Jeer 200mm Gaiven tr= S000N/m %3D * 6- 4000 N/ m N: 500 rpm To design a hiphodynamie bearing, we should follow some standard foramebr Decamelhal cleorance, c =0.025 mm O.025 0.00625 mm - lubricalior film thickness, ho= C= Errentuculy sateo, e = 1- 240 o.00625 E :1- 2 0.025

(1t is a beasing corachristir mnder) (7 dis facloi helps (o prediet the perfomancı f beau) wohere, 2 =46s0luk vascosily of he lubricant N = speed g fournal p : 8eaing pussure on the projectid beaing are a ie.p=_f_ %3D So, for well desigm þurpese, we toke ZN: 1.4 and 0.00/ 0.025 - 25mm 0.001 Deamelei of jourrel, d= 25- mm

- Sornmerfeld mumber, So = 14.31of - Vebrity, v= rde V= Ax 25X10x 500 60 5/ h59.03A both To tal force ona bearing will be- F= So00+40o00=9000 N/m - forse on beaing. A = 1o0 - 4500 N/M Coefficient of ficlión coa be cwiettenas 33 a /08 +0.002 0.00/ 4=0:002 Heat goneretion bearing- = 4.5 KW

- Heat disifalid, Ĉ=Disip-lion coefficiend CA-prea (er) 84 =CA (at) (exd) Ot = y9ox280X 25X 1o) (60-26.5) Ouf = 86.178 J/S is boken half of the system given. Here / gournad (staft)