Hypothetical Question

kinetic747 · 13 Apr 2018 at 15:33

Quite possibly a stupid one but let's say I have a large roller and another roller that is held against the first one hydraulically. Would it be more effective to hold these rollers together magnetically via the side frame/housing, and then push them apart hydraulically when needed? Any thoughts or ridicule welcome.

dirtychinchilla · 13 Apr 2018 at 15:38

If you used electromagnets, presumably you could turn them off when needed.

kinetic747 · 13 Apr 2018 at 15:45

dirtychinchilla said:
If you used electromagnets, presumably you could turn them off when needed.

Yes, that also but I'm thinking of the energy savings.

touch · 13 Apr 2018 at 15:50

I'd guess it makes no difference.

In a hydraulic system, you don't have to constantly input energy to maintain the pressure on the roller. You input the required force at the start and have some sort of valve to maintain pressure.
It wouldn't make a difference if you input that initial energy to push the rollers together or to overcome the magnet and push them apart.

kinetic747 · 13 Apr 2018 at 16:00

touch said:
I'd guess it makes no difference.

In a hydraulic system, you don't have to constantly input energy to maintain the pressure on the roller. You input the required force at the start and have some sort of valve to maintain pressure.
It wouldn't make a difference if you input that initial energy to push the rollers together or to overcome the magnet and push them apart.

Damn!

adolf hamster · 13 Apr 2018 at 16:03

it depends on what you want the rollers to do.

if you want them to maintain a constant seperation distance then hydraulics would be the best answer as it can be locked off.

if you wanted a level of springyness to it, you could use pneumatics or even just a mechanical spring system to hold them together

i can't see how electromagnetism would be much use here, you'd need to constantly input energy in order to hold the rollers together and depending on the size that could be a lot of energy.

rubberduck · 14 Apr 2018 at 00:34

What is your definition of 'effective'?

mrbazmondo · 14 Apr 2018 at 01:07

If it was permanent magnets then the the pressure between the rollers would reduce when something goes between them as the magnets would be further apart.
With hydraulics the pressure would increase as you'd be compressing the piston more.