50cc engines or chain saw engines don't have enough power to get the job done. Consider, one horse power is 550 foot-pounds per second. OK, so lifting 550 pounds five feet in one second is a theoretical five horsepower. The actuator efficiency is about 90% overall, the pump is probably 80% volumetric and about the same mechanical. The servo valve is about 50% at best so we need: 5/(0.9 x 0.8 x 0.8 x 0.5) or 5/0.29 or 17.4 honest horsepower input to the shaft.
That's just using one actuator. If our suit is going to be moving it's other articulating joints, each will add to the required total. The hydraulic circuit will have one pump and dozens of actuators in parallel through servo valves. The function doing the most work will set the pressure generated at the pump and any other function will have to be throttled down to it's required pressure by it's servo valve.
You can save power by slowing down and allowing more time for each operation but that is not a plus for combat situations. Also consider that you are not going to sneak up on anyone with a full throttle go-cart engine strapped to your back!
Some of the newer battery technologies look good as well as fuel cells but in any event you are going to stand out like a search light to any infrared scanner.
Regards,
GtG
No, that would be a theoretical 25 horsepower.
Naturally there would need to be a storage device of somekind to supplement power during periods of peak demand. Batteries or capacitors would suffice. In the case of a hydraulic system, some kind of pressure reservoir would do the trick.
But the human isn’t totally helpless. THe exoskeleton is only meant as a “helper”, not the sole source of muscle power. So lifting 550 pounds five feet in one second would only require 8/11ths of 25 horsepower, or 18 horsepower...assuming the human can do 150 lbs on his own without the exoskeleton.
But a hightech 50cc motor with turbocharger, fuel injection, etc, should give you minimum 6 horsepower. Very likely twice that. If you go to a wankel, or better yet, a turbine, then your power output to engine weight ratio goes even higher, but your fuel efficiency goes down.
As far as infrared goes...a human without an exoskeleton stands out like a search light.
My bad. I have know Idea where I got 25. But that makes the 50cc motor even more doable.
A sophisticated motor is fully capable of developing 2 horsepower per cubic inch. 50cc is 3in^3. That means 6 horsepower potential. With extreme levels of turbo boost and very high RPMs, you can double that figure easily.
Alright, now that I got this done, It’s back to bed for me.