Translational equivalent to Mechanics.Rotational.Components.IdealGear

[grondilu]

A scissor mechanism can be seen as a linear analog to a gear. Yet as far as I can tell it is not implemented in Mechanics.Translational.Components.

It could be called IdealScissor. I may try to implement it but I'm new to Modelica so I would probably do a terrible job.

PS. Like maybe something like this :

model IdealScissor "Idealized scissor mechanism without inertia"
  extends Modelica.Mechanics.Translational.Interfaces.PartialElementaryTwoFlangesAndSupport2;
  parameter Real ratio(start=1) "Transmission ratio";

equation
  s_a = -ratio*s_b;
end IdealScissor;

though that may be too easy. Would it work?

[HansOlsson]

Interesting - but to me a scissor mechanism seem more 3D (or 2D) than 1D-Translational; but I'm no expert in using such models.

[grondilu]

It is reduced to 1D in the idealized model where we neglect its mass.

[christiankral]

The two translational flanges act in different directions, however. This might be confusing when placed in a 1D translational package. Some more issues are:

• The force balance is not yet considered in the proposed model
• The model would then require two support flanges for either direction

I wonder if there exists a purely 1D scissors model which could be implemented. Otherwise this model rather belongs to 2D or 3D implementation.

[tobolar]

I agree with @christiankral .
The suggested solution is oriented on Rotational.Components.IdealGear, having two flanges and a support, and could be implemented similarly. But the question is, what is a use case for such an element.

IMO a scissors, as a real life example, would need four flanges. One of them could be declared as support per default. An implementation is possible.

[beutlich]

For the reference, there also is #1873.