What are the main parameters of the trapezoidal screw?

What are the main parameters of the Trapezoidal Screw? Trapezoidal screws can convert Linear Motion into rotary motion, or convert rotary motion into linear motion, with a conversion efficiency of 70%. Because of the relatively large lead, they provide faster feed when rotating at low speeds. Speed is the better choice.

1. Outer diameter-the diameter of the imaginary cylindrical surface that coincides with the crest of the external thread-also known as the nominal diameter.

2. Inner diameter-the diameter of an imaginary cylindrical surface that coincides with the bottom of the external thread, which is used as the calculated diameter of the dangerous section in the strength calculation.

3. Pitch diameter-the diameter of the imaginary cylindrical surface where the tooth thickness and the width between the teeth are equal in the axial section, which is approximately equal to the average thread diameter d2≈0.5.

4. Pitch-the axial distance between two adjacent teeth on the generatrix of the cylindrical surface of the middle diameter corresponding to the two points.

5. Lead-the axial distance between two adjacent teeth on the same spiral line and the corresponding two points on the generatrix of the pitch cylindrical surface.

6. Number of threads-the number of thread helixes, generally for the convenience of manufacturing n≤4 The relationship between pitch, lead and number of threads: L=nP.

7. Helix angle-the angle between the tangent of the helix on the cylindrical surface of the middle diameter and the plane perpendicular to the axis of the helix.

8. Thread angle-the angle between the two sides of the thread profile in the axial plane of the thread.

9. Thread bevel-the angle between the side of the thread and the vertical plane of the thread axis.