Brake Design And Calculation 6r3h2g

MACHINE DESIGN EXCEL SPREAD SHEETS Copy write, © Machine Design Spreadsheet Calculations by John R Andrew, 6 July 2006 Spread Sheet Method: 1. Type in values for the input data. 2. Enter. 3. Answer: X = will be calculated. 4. Automatic calculations are bold type.

DISC BRAKE A sectional view of a generic disc brake with calipers is illustrated right. Equal and opposite clamping forces, F lbf acting at mean radius Rm inches provide rotation stopping torque T in-lbf.

Calculate Brake Torque Capacity Clamping force, F = Coefficient of friction, μ = Caliper mean radius, Rd = Number of calipers, N =

Braking torque, T =

SHOE BRAKE stopping capacity is proportional to the normal force of brake shoe against the drum and coefficient of friction.

Input 50 0.2 7.00 1 Calculation 2*μ*F*N*Rm 140

lbf in -

in-lbf

Calculate Brake Torque Capacity Coefficient of friction, f = Brake shoe face width, w = Drum internal radius, Rd = Shoe mean radius, Rs = Shoe heel angle, A1 = Shoe angle, A2 = Shoe mean angle, Am = Right shoe maximum shoe pressure, Pmr = Left shoe maximum shoe pressure, Pml = C=

Input 0.2 2 6 5 0 130 90 150 150 9

in in in degrees degrees degrees lbf/in^2 lbf/in^2 in

Calculation X = (Rd - Rd*Cos(A2)) - (Rs/2)*Sin^2(A2)) X= 8.3892 Right shoe friction moment, Mr = ((f*Pm*w*Rd)/(Sin(Am))*(X) Mr = 3020 in-lbf Y = (0.5*A2) - (0.25*Sin(2*A2)) Y= 1.3806 Right normal forces moment, Mn = ((Pm*w*Rd*Rs)/(Sin(Am))*(Y) Mn = 12426 in-lbf Brake cylinder force, P = Answer: P =

(Mn - Mr) / C 1045

lbf

Z = ((Cos(A1)-Cos(A2)) / Sin(Am) Z= 1.6427 Right shoe brake torque capacity, Tr = f*Pm*w*Rd^2*(Z) Tr = 3548 in-lbf

This is the end of this work sheet.