Iy = pi/64 * (De^4 - Di^4)

Dynamically Loaded Compression Spring Excerpt

De = 17ñ0.15 mm d = 2ñ0.035 mm w = 7.5 k = 1.18 n = 9.235 nt = 11.24 nt-n = 2 tauz = 876 N/mm² tauhz = 570 N/mm² Rm = 1565 N/mm² ====================================================================== Spr.Length.mm Spr.Path mm Spring Load N tau N/mm² S ====================================================================== L0= 38.00ñ0.89 L1= 35.00 s1= 3.00 F1= 15.27ñ4.69 tauk1= 86 10.14 sh= 7.00 Fh= 35.63 taukh= 202 2.83 L2= 28.00 s2= 10.00 F2= 50.91ñ5.03 tauk2= 288 3.04 Ln= 27.97 sn= 10.03 Fn= 51.05 taukn= 289 3.03 Ln= 27.97 sn= 10.03 Fn= 51.05 taun = 244 3.59 Lc= 22.86 sc= 15.14 Fc= 77.06 taucn= 436 2.01 Lc= 22.86 sc= 15.14 Fc= 77.06 tauc = 368 2.38 ---------------------------------------------------------------------- (S = tau zul. / tau y)For all springs, the index n stands for the usable spring path. The definition for compression springs however, is completely different to that for extension and torsion springs. For compression springs the usable spring travel is defined as the block spring travel minus a safety margin Sa. For extension and torsion springs the spring travel or spring angle at which the permissible shearing or bending stress is attained. For compression springs, tau n can be greater or smaller than tau zul, but for extension and torsion springs tau n is always equal to tau perm or sigma n is equal to sigma perm. The table in FED2+ and FED3+ has been appended by the stress correction values. However, the reduced spring path, spring forces and spring moments at which the permissible stress under dynamic load are attained, are shown instead of the increased stress for sn. Excerpt of a dynamically loaded extension spring:

De = 10.05ñ0.25 mm d = 1.3ñ0.015 mm w = 6.73 k = 1.21 tauz = 777 N/mm² tauhz = 397 N/mm² Rm = 1726 N/mm² ====================================================================== Spr.Length.mm Travel mm Spg.Force N tau N/mm² S ====================================================================== L0= 27.47ñ0.8 F0= 8.47 tau0 = 86 L1= 39.98 s1= 12.51 F1= 45.62ñ5.38 tauk1= 559 1.39 sh= 10.00 Fh= 29.69 taukh= 364 1.09 L2= 49.98 s2= 22.51 F2= 75.31ñ5.83 tauk2= 923 0.84 Lkn= 45.96 skn= 18.49 Fkn= 63.38 taukn= 777 1.00 Ln= 50.41 sn= 22.94 Fn= 76.58 taun = 777 1.00 ---------------------------------------------------------------------- (S = tau zul. / tau y)Dynamically Loaded Torsion Spring Excerpt

Dm = 20.49ñ0.484mm d = 1.4ñ0.025 mm w = 14.63 q = 1.10 n(if) = 1.833 a = 0 mm LK0 = 4.038ñ2.108 mm E = 206000 N/mm² sigma z = 1523 ====================================================================== Install.Angleø Spring Angleø Torque Nmm Sigma N/mm² ====================================================================== delta0= 329.9ñ17.0 alfa0= 0.0 T0= 0.00 sigma0 = 0 delta1= 307.0 alfa1= 22.9 T1= 130.00ñ84.34 sigmaq1= 530 alfah= 30.0 Th= 170.00 sigmaqh= 693 delta2= 277.0 alfa2= 52.9 T2= 300.00ñ84.34 sigmaq2=1223 deltaqn=264.0 alfaqn= 65.9 Tqn= 373.71 sigmaqn=1523 deltan= 257.5 alfan= 72.4 Tn= 410.30 sigman =1523 ----------------------------------------------------------------------