POWER TRANSMISSION REFERENCE GUIDE
Key lead screw
selection criteria
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any motion systems incorporate lead screws to drive machine axes. Lead screws are often used in linear actuators and positioning equipment to provide thrust or axial force to drive a load. A lead screw is basically a threaded rod that uses rolling friction between the screw and a nut to translate rotational motion into linear motion. The sliding action generates high friction, meaning a lower efficiency rating. However, lead screws generally sport higher power ratings than comparable ball screws, mainly because of the greater area of surface contact between the screw and nut. Selecting the right lead screw involves knowing the specific application parameters as well as a bit of manual calculation aided by online selection tools offered by most manufacturers. The most
important is choosing the right diameter lead screw and the lead. There are four steps to getting this right; determining the axial load, checking the critical speed of the screw, calculating the PV value, and considering back driving. Once you’ve gone through the process of sizing a lead screw, you know what diameter and lead will provide the required load capacity, speed, and back driving torque for the application. But there are hundreds — maybe thousands — of lead screw designs on the market. Beyond the basics of diameter and lead, how do you choose the specific lead screw assembly that will work best in your application? The final lead screw selection often comes down to three factors: backlash, material, and customization.
LEVEL
to Superior Life, Precision, Lead • The NEW Standard for Accuracy and Life!
• Innovative Anti-backlash Nut!
Lead accuracy at 2–3 times
Patented Design delivers
the industry baseline achieved
2–4 times better performance
with German CNC Roll Thread
than conventional designs
machinery and advanced process
as validated in customer testing.
control and metrology.
Lead Screws — Power Transmission HB 05.19_v2.indd 34
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