Lead Screw, Ball Screw, and Roller Screw Cylinders: What's the Difference?

[@jameselliott9397]

I hope you’re doing well! I have a couple of ideas for an AUTO DISENGUAGING lead screw nut that I’d like to share with you. Segmented Nut Design: This would involve the nut being split into 2 or 4 pieces, held together by a spring. When the screw hits a stop, a spreader cone would disengage the nut. Cone-Shaped Ramp Nut: In this idea, a cone-shaped ramp nut could be positioned at the end of the shaft or along it with a jam nut. A spring-loaded half nut would then roll up onto the ramp to disengage. I think both concepts could offer some interesting functionality. Let me know your thoughts, and if you’d like to chat further! Best, Dean

[@heartminer5487]

how much stronger is roller screw compared to ball screw for the same form factor?

[@keithviolette5870]

I know this is an old question, but typically the roller screw can carry at least twice to many times the axial load of a ball screw. The balls contact at points, only two points (or 4 points) per ball. For the rollers, they have line contact at several locations along the length of each roller, so there is more area in contact to absorb the force, and lower contact pressures.

[@Dezzsoke]

but can it be backdriven?

[@keithviolette5870]

Yes, as the efficiency of roller screws tend to be high, they can be backdriven. Even with small screws, such as a Ø5mm diameter screw with a 1mm pitch can easily be back-driven.

[@mervenur6376]

What is meant by saying impact tolerance?

[@rkusuma6852]

I guess, the resistance of impact whether it would be scratch, bend, etc

[@keithviolette5870]

If you were to hit the end of the screw with a hammer, the impact load would travel through the balls or rollers into the nut. In the case of the balls, if the impact is high enough, they will dent the surface they are rolling on, a term called Brinelling. (en.wikipedia.org/wiki/Brinelling) As the rollers have many more contact points and use line contact, the impact force is distributed over a larger area at a lower pressure, so the surface doesn't dent as easily.

[@tr_2292]

@@keithviolette5870 Thank you!

[@nzljohn]

Great explanation. Would be even better without the music.

[@kls2020]

Agree but it could be worse . At least there are no dancers going in the background along with music like the typical product TV commercial these days . They could be selling wheelchairs or Tombstones and the TV Commercial would still have music and dancers .

[@aniljai405]

5 tan cepisiti numeric & prises juice press Anil kumar

[@ChrisGWGreen]

From the salesman - "The main disadvantage is the cost..." ... 🤔 ... Erm... sell it cheaper then?

[@DomCamilone]

Production cost is elevated comparing to a cheaper and simple-engineered option