How to ensure maximum possible joint torque for an actuator?

AI Thread Summary
To achieve maximum joint torque for an actuator in a joint system with a fixed anchor and a moving arm, the actuator must be positioned to maintain a mechanical advantage of 1, meaning it generates force equal to the load on the moving arm. The challenge arises from the requirement that the actuator's fixed end must be close to the moving arm, limiting the effective perpendicular distance to the pivot, which diminishes torque. The discussion highlights the misunderstanding of constraints versus optimization goals, emphasizing that the actuator's placement is critical for performance. Properly addressing these constraints can lead to better solutions for maximizing torque. Understanding the relationship between force application and pivot distance is essential for effective actuator design.
TheShermanTanker
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Below, I have a joint system that consists of a fixed anchor and a moving arm:
2020-05-08.png


What I want is simple: To attach a linear actuator on the moving arm in such a way that the mechanical advantage of the actuator is exactly 1 (Ie the actuator only has to generate exactly the amount of force as the load on the moving arm)

This may seem simple at first glance, just attach the actuator at the far end of the moving arm, right?

But there is a necessary constraint: The other end of the actuator has to be fixed to the fixed arm AND has to be as close to the moving arm as possible, I can't just stick the other end to anywhere I want. So now I end up with this:
2020-05-08 (1).png

The problem is that torque generated depends on perpendicular distance to the pivot. So no matter how far out I fix the actuator, it's still at a mechanical disadvantage, since the actual perpendicular distance to the pivot is very small

Anyone know how I can fix this issue?
 
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Why not just fix the actuator to the moving arm? It just needs to push the load straight away from the end of the moving arm, right? Why does this force need to be transferred to the fixed arm through anything but the pivot bearing?

I guess I'm not understanding your problem statement so far...
 
TheShermanTanker said:
But there is a necessary constraint: The other end of the actuator has to be fixed to the fixed arm AND has to be as close to the moving arm as possible,
That's not a constraint, but an optimization goal.

TheShermanTanker said:
I can't just stick the other end to anywhere I want.
That's an ill-defined constraint.

TheShermanTanker said:
(Ie the actuator only has to generate exactly the amount of force as the load on the moving arm)
That's a constraint.
 
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