Problem understanding the forces applied to a threaded fastner

[Amaelle]

TL;DR Summary

Threaded fastner

Greeting I have a problem understanding the forces applied to a threaded fastner

I really don't understand from where they got Pr or PL because for me the only applied force is F
thank you!

 

[Dullard]

The confusion is probably because the diagram isn't for a threaded fastener - it's for a 'Power Screw.' The screw is raising (or lowering) a load - that's where the 'mystery' forces come from.

 

[onatirec]

PR and PL correspond to the torque required to turn the screw (and lift or lower the load).

 

[Amaelle]

The confusion is probably because the diagram isn't for a threaded fastener - it's for a 'Power Screw.' The screw is raising (or lowering) a load - that's where the 'mystery' forces come from.

thank you very much

 

[Amaelle]

PR and PL correspond to the torque required to turn the screw (and lift or lower the load).

thank you I got it now!

 

[dlgoff]

@Amaelle
I just thought I would provide a good reference on threads. See attached .pdf file

 

[Amaelle]

@Amaelle
I just thought I would provide a good reference on threads. See attached .pdf file

thanks a million!

 

[dlgoff]

thanks a million!

You're welcome. Hope it will be useful in your future.