Welcome to this Motion Control Classroom on roller screws and ballscrews.
Absolutely core to linear-motion designs are the three types of rotary-to-linear screw drive types:
- Simple leadscrews (sometimes called ACME or trapezoidal, though profiles and flank geometries abound) — based on sliding contact between the linear screw and nut
- Ballscrews — based on rolling contact between the linear screw and nut (via ball bearings)
- Roller screws — also based on rolling contact between screw and nut (via rollers).
In this Classroom, we present information on the last two linear-motion drive types.
Determining the most suitable rotary-to-linear screw drive for a given machine axis depends on the loads it will move, travel speeds, duty cycles, cost constraints, and the environment in which the machine will run.
In this Classroom, you’ll learn about ballscrew load-life characteristics — and why ballscrews excel where high speeds and loads are present … even while maintaining 90% efficiencies. You’ll also learn how roller screws leverage multiple sets of rollers for exceptional internal contact to withstand high loads and shock even while providing distinct stiffness advantages over ballscrews — and maintaining 84% efficiency or better. In fact, electric thrust actuators incorporating both screw types (but especially roller screws) have come to rival hydraulic cylinders for some applications — capable of delivering hundreds of kN.
Thank you for reading — and be sure to check out our other Classroom installments at designworldonline.com/mc2.