Planetary roller screw drives, also known as roller screw drives, are precise, backlash-free linear drives that convert rotary motion into linear motion, similar to ball or trapezoidal screw drives. Unlike these, however, they do not use balls or sliding surfaces, but threaded rollers. Roller screw drives thus consist of a spindle with a thread profile, a nut with a corresponding thread, and several threaded rollers (the “planets”) that roll between the spindle and the nut. The threaded rollers are arranged at an angle to the axis and roll with low friction between the spindle and the threaded nut. They are synchronously guided by an integrated system, preventing slippage. The rollers transmit power and enable high load capacity with simultaneously low friction.
While roller screw drives also offer precision and stability, they do not provide the same efficiency and speed as a ball screw drive. Although roller screw drives, due to their design with threaded rollers, exhibit higher load capacity and rigidity, they are generally heavier and less flexible in application. Another advantage of ball screw drives is the wide variety of sizes and designs available, which allows for easier integration into existing systems. Furthermore, due to their lower friction and higher efficiency, they are often the more economical choice, as they consume less energy and reduce operating costs.