Documentation/Modules/Power & Ball Screws

Power & Ball Screws

Lead screw efficiency, torque and buckling screening

Standards catalog

Validation: indicative · Method band: formula

Open calculator

Indicative method: Indicative closed-form or numerical model

Assumptions

  • Linear elastic material behavior unless noted otherwise.
  • User is responsible for load combinations and load factors per the selected design code.
  • Design standard (US/EU/ISO) sets unit defaults and screening check labels — not a full code worksheet.

Limitations

  • Professional screening / indicative workspace — does not replace a licensed PE or official code compliance review.
  • Where specialized evaluators are not implemented, checks map solver outputs to catalog templates for orientation only.

Engineering checks

CheckINDUSEUISO
Drive efficiencyimplemented———
Thread safety factorimplemented———
Required torqueimplemented———

Power & Ball Screws (power-screws)

Purpose

Design and check power screws and ball screws for torque, efficiency, thread stress and buckling margin.

Physics & theory

A power screw converts torque to axial force through thread friction. Efficiency depends on lead angle and friction coefficient. Ball screws add rolling friction with higher efficiency. Column buckling and whirling may limit unsupported length at speed.

Governing equations

Numerical method

Thread-aware screening via solveScrewEngine / solveScrewFEM with square, Acme and ball-screw configurations.

Inputs

ParameterDescription
screwTypePower screw or ball screw
majorDiameter, pitch, lead, lengthGeometry
axialForce, frictionCoefficientLoad and friction
threadType, startsThread form (power screws)

Outputs

  • Required torque, efficiency, thread and column safety factors, power, recommendations.

Design codes & checks

  • Indicative: Thread stress and buckling screening
  • US: Shigley / machinery handbook references

Assumptions & limitations

  • Uniform load, no nut compliance FEA. Ball screw speed limits are indicative.

References

  1. Shigley, J. E., & Budynas, R. G. Mechanical Engineering Design, Ch. 8.
  2. MITCalc Power Screws and Ball Screws — independent benchmark context.
Maintainer note: Power and ball screw efficiency and buckling.