Question

130 points) 3D Equilibrium. A vertical force of 50 lb acts on the crankshaft. Determine the horizontal equilibrium force P that must be applied to the handle and the x, y, z components of reactions at the journal bearing A and thrust bearing B. Recall that in journal bearings, the shaft is free to move within the support but thrust bearings restrict translation along the shaft. The bearings are properly aligned and exert only force reactions on the shaft. Complete the FBD. CRD

Answer 1

Moment balance about y-axis 8 x P - 10 x 50 = 0 → P= 10 50 =- P = 62.5 lb 8 Fx = 0 → Ac + Bx - P=0 → Ax + Br = 62.5 ---------(i) EF, = 0 + B, = 0 EF, = 0 → A. + B. – 50 = 0) + A + B. = 50 ----------(ii) Moment balance about x-axis -14 x 50 + 28 x B =0 14 x 50 B:= a 98 →B, = 25 16 Put value of B, in equaiton (ii) + A + 25 = 50 → Az = 25 16 Moment balance about z-axis → –(4 + 6 x P - 28 x B = 0 10P 10 x 62.5 +Be=-28 =- 28 "→ Bc = –22.3214 lb Put value of B, in equaiton (i) → Ax – 22.3214 = 62.5 → A, = 84.8214 lb