Nexen Roller Pinion System
Precise Motion with No Play, Over Any Length
In a normal rack and pinion, the teeth slide and leave a little play. Nexen’s pinion uses rollers on bearings instead, so there’s no play and the error doesn’t add up over distance – for long linear axes and precise rotary tables.
- ±30 µmpositioning accuracy
- 11 m/smax. speed
- 99%efficient
- 274 partsracks, pinions, gears and drives
The range
Rack & Pinion
Racks
Standard and corrosion-resistant racks, joined to any length.
- 55 parts
Pinions
Roller pinions to fit common gearboxes, with adapters.
- 24 parts
- up to 4,000 rpm
Preloaders
Set how firmly the pinion meets the rack.
- 15 parts
Gears
Roller pinion gears and gear segments, with teeth outside or inside.
- 37 parts
- 183–72,800 N·m (1,622–644,287 lb·in)
- up to 607 rpm
Geared Bearings
A no-play gear on a heavy-duty bearing, with a large open centre for cables.
- 143 parts
How it works
How the Roller Pinion System Works
Nexen’s pinion has rollers on bearings in place of teeth. The rollers roll down the rack teeth instead of sliding, so the drive is precise, efficient and has no play.
Rollers in Opposition
Two or more rollers are always touching the rack, pushing from opposite sides – so there’s no slack to take up when the axis changes direction.
Efficient and Quiet
Because the rollers roll rather than slide, the system is over 99% efficient, quiet, and can run without grease. Rack sections join to any length.
Shorter Drive
A harmonic gearhead with the pinion built in is up to 70% shorter than a two-stage planetary, with no play from motor to rack.
The Forces to Size for
Sizing starts with the forces on the pinion: accelerating the load, lifting it if the axis is inclined, and friction in the guides.
How Much Thrust?
This follows Nexen’s rack selection steps. Compare the result with the rack thrust ratings.
Thrust on the pinion
Force = (mass × acceleration + mass × g × sin angle + friction) × shock factor – Nexen’s rack selection steps (guide pp. 10–11). Defaults are Nexen’s sample.
Why the Roller Pinion System
Accurate Over Any Distance
No Play
The rollers meet each tooth cleanly, so there’s no slack to take up when the axis reverses.
No Build-Up of Error
Rack sections line up with a simple tool, and accuracy holds over any length.
Quiet and Clean
Low friction and low noise, and it runs without grease – good for dirty, food and vacuum areas.
Straight or Round
Racks for long straight travel; gears, geared bearings and ring drives for rotary tables.
Literature & related
More Information
- Precision Motion Control catalogue
Racks, pinions, gears, geared bearings and gearheads - Zero Backlash Gearing (21604)
Geared bearings - Precision Ring Drive Systems (21603)
Ring drives
Not Sure What You Need?
Tell us what the machine has to do – the load, the speed, how often it runs and the space you have – and we’ll help you choose the right Nexen product.