planetary roller spider
Planetary roller screw for high-precision, maintenance-free linear drives.
Planetary roller screws – also known as planetary threaded screws or planetary roller threaded screws (PWG) – are used wherever the highest demands are placed on dynamics, positioning accuracy, and durability. Ortlieb's servo spindle technology combines a precise guide mechanism with a self-locking roller principle, offering a low-maintenance drive concept for demanding industrial applications.
Alternative linear solutions can be found in our electric cylinders.
Functional principle of the planetary roller screw:
The planetary roller screw is based on a threaded screw that is guided by several rotating rollers – the “planets.”
This multi-point contact geometry results in particularly uniform force transmission and low-friction operation.
The results are:
High rigidity with a compact design
Low friction and heat generation
Efficient force transmission
High inherent rigidity even under changing loads
This operating principle makes PWGs ideal for dynamic and precise linear movements.
Advantages of Ortlieb planetary roller screws:
Ortlieb manufactures planetary roller screws with maximum precision and modern production technology.
The advantages at a glance:
Very high power density with minimal installation space
Backlash-free operation for precise positioning
High dynamics and acceleration
Long service life thanks to robust materials
Low-maintenance design
Finely tuned manufacturing for maximum repeatability
Individual configuration (pitch, diameter, stroke, etc.)
PWGs are therefore a key component for modern linear systems that require both performance and efficiency.
Technical features
Compact unit with spindle, guide and optional measuring system
Optionally available with integrated motor mount (e.g., SERAC®). More about spindle drive technology.
Self-locking principle – reliable even in case of power failure
Long lifespan without relubrication
High axial forces transferable over long distances
Applications and areas of use:
Planetary roller screws are used wherever linear movements must be dynamic, precise, and resilient. Typical areas include:
Machine and plant engineering
Automation technology & handling systems
Test benches and measurement technology
Servo drives and compact linear axes
Highly dynamic feed systems
Special machine construction
Thanks to their compact design, they can also be integrated into machines where conventional spindle systems would be too large or too heavy.
Typical areas of application
Handling axes in production lines
Machine adjustments under load or workpiece clamping with power chucks
Test stands with high-frequency motion dynamics
Assembly units with tight installation spaces
Applications with security requirements in case of failure
Through the development of the SERAC® electric cylinders, all the technological advantages of an Ortlieb servo spindle can be utilized in a series-produced complete solution.
Combination with spindle drives and electric cylinders:
Planetary roller screws are often used as core components in system solutions:
Spindle drives for precise feed movements
SERAC® electric cylinders for highly dynamic electric linear systems
Ortlieb servo spindles as the basis for compact and energy-efficient linear axes
These combinations enable powerful linear movements for a wide range of industrial requirements.
Frequently asked questions about planetary roller screws
What distinguishes planetary roller screws from planetary threaded screws or PWG?
These terms refer to the same principle: a screw with rotating rollers for powerful, backlash-free linear motion. At Ortlieb, the technical term “planetary roller screw (PWG)” is used for this.
What distinguishes a planetary roller screw from a ball screw?
PWGs offer higher power density, greater rigidity, and often a longer service life - ideal for compact and highly dynamic systems.
Is individual design possible?
Yes, diameter, pitch, stroke, and interfaces can be adapted to the application.
How maintenance-intensive is a planetary roller screw?
It is virtually maintenance-free. When used with a lubrication unit, very long maintenance intervals are possible.
Are there variants with sensors?
Yes, the systems can be combined with position measuring systems, encoder connections, or end position sensors.