Comparison of Axial Stiffness Combination Spring Bearing Capacity P=P1+P2=(Gd18c3n1+Gd28c3n2)F=134.94F Bearing Capacity of a Primary Cylindrical Spring P=Gd28c3n2=93.3F Axial Stiffness of Combined Spring Spring Axial Stiffness= 134.94F93.3F = 1.446, so the axial stiffness is significantly increased.
Comparison of Lateral and Bending Stiffness The lateral stiffness of a single spring can be calculated by the following formula: Pr = Ed48nD32F The bending stiffness of a single spring can be calculated by: M = Ed416D2nH(2+L)Fr The combined spring axial stiffness The original spring axial stiffness =d41D2n2H+d42D1n1Hd42D1n1H=1.225 This ratio is clear, and the stiffness of the combined spring in all directions is greatly improved.
Improvement of the secondary spring The secondary spring is located between the bogie and the carriage. After the speed increase of the locomotive, the increase of the exciting force makes the transverse stiffness of the secondary spring low, and the anti-resonance ability is poor. For this reason, the characteristics of the spring are changed by changing the shape of the spring while ensuring that the weight of the body is not increased. According to relevant data, the general cylindrical compression spring has a characteristic curve that approximates a straight line, is stable in rigidity, simple in structure, and easy to manufacture. However, the spring is mainly along the axial direction, and the transverse shear and bending stiffness are poor, and the anti-resonance ability is poor. The tapered spiral conical compression spring has a gradually increasing characteristic curve, that is, its stiffness is gradually increased, which helps to eliminate or relax the resonance, and has a compact structure and good stability.
The design of the second-system conical compression coil spring The original two-system spring parameters: D2 = 230mm, d2 = 48mm, effective working number of turns 6.6, total number of turns 8.1, free height H0 = 528mm, material 50CrVA. If the upward diameter decreases by 3 ) 5mm (actually take 4) calculation is [email protected] = 203.6mm according to the pitch of the conical coil spring design, then on the premise of guaranteeing high freedom, the distance can be calculated by H0 = 6.6t + 1.5d then t = ( 528-1.548)/6.6=69.09mm Pressure and time interval: dc=d1-(R2-R1nd)2=481-([email protected])2=47.96mm Load calculation formula Pi=Gd464R3i(t-dc)[email Protected](69.09-47.96)[email protected]Firming formula Fi=nR2-R1[email protected][email protected])+10.565(115-Ri)>When Ri=R2, the conical spring starts to have a spring The load on the ring contact is: [email protected]=9218.4kg The corresponding deformation is: [email protected]@[email protected]([email protected])=116mm When Ri=R1, the available conical spring begins to have The load on the spring coil contact is: [email protected] = 13289.3kg The corresponding deformation is: [email protected] (115-101.8) = 139.4mm The original cylindrical spring is composed of P)F As can be seen from the line, the longitudinal stiffness of the modified conical coil spring is increased compared to the original cylindrical spring.
Calculation of transverse shear stress (P)S curve comparison) Shear stress at the time of contact S calculated: [email protected]@[email protected]@483=64.7 kg/mm2 where K is the curvature coefficient o Shear stress at full compression S calculation: [email protected] @ [email protected] @ 483 = 85.7585.75kg/mm2 conical spring P) S cylindrical spring P) from the P) S curve, although the shear stress difference is not too large, but the cone spiral spring P) The S curve is more reasonable.
Conclusion The design of the first and second series spring systems for high-speed electric locomotives plays a key role in the quality of the entire locomotive. By improving their design, the excitation force generated during the high-speed operation of the locomotive can be greatly reduced, and the lateral rigidity and the axial stiffness are increased. Thus, the active control of the locomotive during high-speed operation is realized, and the locomotive operation safety is improved. Sex and smoothness.
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