How can I use Pneumatic Muscles as Hydraulic Muscles?

[Warren Pnigel]

Hi everyone, this is my first post
I was wondering how can I turn a pneumatic artificial muscle into a hydraulic one using water.
http://www.instructables.com/id/How-to-make-air-muscles!/ These are the air muscles I was planning on using.
What sort of pump would I need? Please be specific as I'm not very experienced with this.
Thanks!

 

[Baluncore]

Welcome to PF.
There is no obvious problem changing the working fluid from air to water.
If you want speed, use pneumatics with a high pressure reservoir. If you want power use hydraulics with a low pressure reservoir tank and pump.

Air trapped in a hydraulics system can reduce rigidity and increase danger. That is because the compressibility of gas can store more energy than a liquid. With air in the system a hose failure can empty the hydraulic fluid very rapidly. There must be a way to vent air from the system.

Add car radiator antifreeze = ethylene glycol 33% to your water, 67%. It will reduce corrosion in your pump and valve system. It also prevents freezing in winter which can damage valves and will also help identify the source of leaks.

 

[Warren Pnigel]

Thanks! Just for the point of using hydraulics, I'd like to use hydraulics :D even though it sounds dumb. Can you recommend a fast pump at all?

 

[Baluncore]

I think your first move should be to make a "muscle" and identify the magnitude of the load that will be applied to the muscle. From that position you can measure the volume of fluid and the pressure needed to actuate the mechanism as the length changes. You will then be in a position to select a pump. You will also need some form of pressure relief or safety valve to protect the muscle.

There are a couple of topological possibilities, you could have only one pump but several valves, one valve for each muscle, or you could have a pump for each muscle, without any valves. Will the energy to drive the pump come from an electric motor?

 

[Warren Pnigel]

Yes, I'll drive the pump with a motor. I already have a motor laying around which I'll use for testing, but it's not very strong. I'll probably upgrade it later.

 

[Warren Pnigel]

Thankyou for taking the time to reply to this thread as well, you've helped me alot! :)