Feature

Planetary screw drive offers high load capacity and power density

Schaeffler (UK) has extended its range of spindles by introducing a screw drive with a new design and functional principle, which provides a high load carrying capacity and high power density.

10/10/2015 11:57:36

The high power density of the new PWG range of planetary screw drives means that it can also be used as an alternative to hydraulic drives. The design incorporates planetary gears with V-shaped parallel grooves, which roll up and down the spindle.

The rotation of these planetary gears and the planetary screw drive is achieved by using a two-piece screw drive nut, which also has grooves at the ends that engage with the ends of the planetary gears.

A high number of rolling contacts means that the PWG achieves a higher load carrying capacity and rigidity than the KGT and RGT ranges. Friction levels remain low due to good internal load distribution and the optimised osculation between the spindle thread flanks and the crowned flanks of the planetary gear grooves. When planetary gears with the correct groove diameter are selected, overall pitches of just 0.75mm to 5mm can be achieved.

The PWG generates 200N of axial force from just 40Ncm with an overall pitch of 0.75mm. As a result, very high axial forces can be achieved using small electric motors.

Written By Sophia Bell

Sophia Bell is the Group Editor of DPA, Connectivity, and PBSI. She joined the team in 2020 as Assistant Editor after achieving a First-Class Honours BA in English Literature and Film Studies from the University of East Anglia. In her current role, she leads the editorial strategy, driving digital growth and ensuring each title continues to deliver trusted, relevant insight for engineering and manufacturing professionals.