Calculate resultant force of a linear mechanism

[Travis T]

TL;DR

Would like to calculate force required for a wedge cam design

Hi all,

I'm currently designing a linear to linear transform mechanism (wedge cam design).

Would like to check how much force required to push/ slide the roller down.
To ease calculation, i have include some assumption:

F2 = 1kg @ maximum compressed
angle = 20degree
F1 required = ?

and how to draw the resultant force diagram for this example?

Thanks.

 

[jrmichler]

Is this homework?

The resultant force diagram is centered on the point where the roller contacts the wedge. The force vector is perpendicular to the surface at the point of contact. You have the vertical component of that force vector. Get that part of the diagram right before doing the calculations.

 

[Travis T]

Thanks for reply,

It is not a homework.
It is for machine designing.
The figure is just drafted to show basic mechanism motion.

 

[Dr.D]

The force vector is perpendicular to the surface at the point of contact.

The normal force is certainly normal to the surface, but there will also be some amount of friction tangent to the surface.

 

[Baluncore]

Since the two forces are orthogonal; F1 = F2 * Tan( 20° )

 

[Travis T]

The normal force is certainly normal to the surface, but there will also be some amount of friction tangent to the surface.

If the roller is mounted with bearing, will friction force insignificant and can be ignored?

 

[Baluncore]

If the roller is mounted with bearing, will friction force insignificant and can be ignored?

If the bearing is a simple cylindrical pin then friction will depend on lubrication and it may be a problem. If the bearing is a low friction rolling bearing then friction will probably not be a big problem.

 

[Lnewqban]

If the roller is mounted with bearing, will friction force insignificant and can be ignored?

The friction force between slider and sliding surface may be a bigger problem regarding additional F1 needed to overcome friction.