Question

A camshaft rotates 650om, onusing a follower to neise and lower once Jer revelution. The Aillouer is to be held agninst throw." by ฟื hehal compression spring trith a force that rwries etwven 300 and 600 N as the spring length earies over a range of 25 mN. Ends are to be spuared and ground. The material is to be chrome- ninahum sterulve spring Trire, ASTM A232 Calculate k. al, D. i. and Lo (C-94, N.-4.95, M,-1.2 and G 78000 N/mm2) Tid " whare Ke 4t2 4C-3 Table 10-1 Type of Spring Ends Plain and Squared or Ground Squared and Ground Formulas for the Closed Term Plain Dimensional End coils, N Characteristics of N. +2 Na +2 Total coils, N N length, Lo pNa d Solid length, L dN+1dN Na + 1 Compression-Springs N Number of Active Free P(N 1 PNa 3d PNa +2d Coils) Pitch, p Table 10-4 Constants A and m of Sa A/d for Estimating Minimum Tensile Strength of Common Spring Wires Source: From Design Handhook, 1987, p. 19. Courtesy of Associated Spring ASTM Exponent Diameter, A Diameter, A No. Cost kpsi in"mmMPa.mm of Wire in Material 2.6 0.10-6.5 2211 201 0.145 0.004-0.256 0.187 0.020-0.500 A228 Music wire 1.3 05-12.7 147 OQ&T wire Hard-drawn wire A229 1.0 0.7-12.7 140 0.190 0.028-0.500 A227 3.1 Chrome vanadium wire A232 0.168 0032-0437 169 08-11.1 200

Answer 1

So hat 2 5 Diametes lwlxe is as C = Spring Index = S. 4 maximum Sheos Stress 661 MPa てmar- 下 661

Mean Dlamees D s en as Cd- → D=46.784mm D = g, 4 x 4.97 Selid enh is ven s Wheve NaNumbes of civ 4.35 So Thot Ls = 34.5g mm 4.95+2) x 4.373 Ls* engh is iven So hat Lo-34-530 + 12