Roller or Ball screw

[liorg]

Hello everyone,

I'm planning a lilnear driving transmission and I can't decide between using roller or ball screw.
The system is planned for rough enviroment with heavy shocks.
Regarding the numbers. Both of them fits well and have safety factors (2.4 for ball and 6 for roller).
My fears are that althogh the s.f. the ball screw is delicate and won't stand it for long.
Is anyone has experience regarding those two? Or could anyone enlighten me?
Does the roller screw have secret advantages (exept heavy load capacity)?!

Thank you,

Lior G.

 

[MikeHalloran]

If I'm remembering correctly, roller screws have a much lower effective pitch, so they are not directly comparable. Both are rather difficult to seal against dust and water intrusion.

I suggest you contact application engineers at several such manufacturers and ask them to check your calculations and make suggestions for improvement.



Mike Halloran
Pembroke Pines, FL, USA

 

[liorg]

Thanks for the response,

do you knoe something regarding its tendancy to stuck or damaged due to shock loads?

 

[tygerdawg]

If you will experience transient shock loads, then these loads should be part of the sizing exercise. The screw size (and load carrying capacity) would be larger to survive the shock loads and prevent damage to the flights. This may force you to consider other designs.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[tbuelna]

liorg,

If you have reversing loads and/or require low backlash, then a planetary roller screw would probably work better than a recirculating ball screw.

Hope that helps.
Terry

 

[gadkinsj]

From my experience, Shock loads are death to Ball screws. I couldn't speak on roller screws. There are other options out there for linear motion. Roller Pinion, Linear Motor, just to name a couple options.