When selecting material for transmission spring, attention should be paid to the hardenability of steel. Whether the cross-section of spring material is hardened or not and the degree of hardening is of great importance to the quality of spring. The characteristics of gearbox spring material determine the physical and mechanical characteristics of its spring to a certain extent, and affect the design and development of the spring and the promotion of the requirements of particularity.

Gearbox spring parameters

1. Diameter of spring wire d: diameter of steel wire for manufacturing spring.

2. Spring outer diameter D2: maximum outer diameter of spring.

3. Spring inner diameter D1: minimum outer diameter of spring.

4. Spring diameter D: the average diameter of spring. Their formulas are D=(D2+D1)2=D1+d=D2-d.

5. Pitch t: In addition to the support ring, the axial distance between the corresponding points of the two adjacent rings of the spring on the mid-diameter becomes pitch, which is expressed by T.

6. Number of effective cycles n: The number of cycles in which the spring can maintain the same pitch.

7. Number of supporting rings n2: In order to make the spring work uniformly, ensure that the axes are perpendicular to the end face, and manufacture, the spring ends are often tightened together. The number of compact circles only plays a supporting role, which is called support ring. Generally, there are 1.5d, 2D and 2.5d, and the commonly used is 2D.

8. Total number of cycles n1: sum of effective cycles and support cycles. Namely n1=n+n2.

9. Free height H0: The height of spring without external force. Calculated by the following formula: H0 = nt+ (n2-0.5) d = NT + 1.5D (n2 = 2)

10. Spring unfolding length L: the length of steel wire needed for winding spring. L_n1(_D2)2+n2(pressure spring)L=_D2n+hook expansion length(pull spring)

11. Spiral direction: there are left-right rotation, often right-handed, the drawing does not indicate the general use of right-handed.

12. Spring winding ratio: the ratio of diameter D to steel wire diameter D.