Question

Question 4 Refer to the following diagram of a short-shoe brake assembly. Coefficient of friction is .35 • Is the brake self-energizing or deenergizing for the given direction of drum? What is the magnitude of the torque developed by the brake? How far below the drum center would the arm pivot need to be to make the brake self- locking? F = 1500 N 400 mm 500 mm 200 mm Rotation 340 mm

Answer 1

(iii) distance of pivot from center of drum=1142.857-200=942.857mm

F = 1500 N 500 400 M=0 35 200 D 340mm N. 0.17 m, A- 17o mm= the torque due fo frictional force is in Sanne dire tion as () As of torque due C) torque developed by the boake. to force f, es selt energi zing. brake so taking Moment @ pivet pent 'o UN X 200+ fX goo = NX 400. 4N- 2UN - 9x1500 3.3N = gF = 4090.9IN 3.3 friction force eUN = 0.35X4090.9I = 1431 81 N 1431 81 X 0.7 Baking torgue 243.41 Nm Cü) pivoting for self locking. [f=0 4 00 11 42.857 mm %3D 0:35