Question

6. Band Brake A differential band brake is used to control the speed of a drum which rotates at a constant speed. Knowing that the coefficient of kinetic friction between the belt and the drum is 0.30 and that a couple of magnitude 150 N.m is applied to the drum, determine the corresponding magnitude of the force P that is exerted on end D of the lever when the drum is rotating (a) clockwise, (b) counterclockwise. r 140 mm 30 150 mn C 300 mm 30 40 mm P = 646 N P = 47.0 N

Answer 1

FBD OF FOD Of ABD Ctinder TB TA O.3 m Ex TB 2Me B TA 0.1STA 0.04TB P= 210 Yad 34 P Eq.1) COunterclockwise NOW DruM rota tes TB JA TB-TAe Eq C2) TA 3 O

0000000 From FBD of ctin der Me E TB xo.14) (TAXO.14) 150 Eq (3) 29 Eqs C), (2) (3) SOIve Ne get TA 536 N 921W 3 D/ T8 1607 N PE47 N Ans.

When Dum Rotes ClockMise Eq- 1) Tem ains same OI5TA 0.04TB 0.34P Eq 0)) for clo ck wise Yotation 03(7s) TA e TB TA(0.3x10) TB O ET. (4) - 3Tg TA O FBD of CYnder ives Iso M eE o 14 TA 0. 14T=-150 Eq 5 C1), C4) CS) ET. (5) SOIve TA 1607 N P = 646 N Th -536 N