weight=hp and gearig question

"incidentally i do have a way of raising the weight back to its ascendent position free of any energy expenditure- thanx to all"

Please explain more - you have peaked my interest (and the thought of - if you have this energy why not use it to turn your alternator so that you don't suffer any losses)

Assume your alternator is high efficiency @ 70%

Therefore you will need to drive it with 2.85 hp.

The torque of a motor is given by T (ft-lbs) = (HP x 5252)/rpm:

Therefore you need a torque of (2.85 x 5252)/700 = 21.4 ft-lbs

Now this can be accomplished by any number of combinations of sprockets and gearboxes.

Take for example if you have a 5:1 reducer (increaser in this case).

The torque will need to be multiplied by 5 times as well and gearbox efficiency will need to accounted for too (assume a spur gearbox @ 85%).

The input speed will be 700/5 = 140 rpm

Power in = power out: Pin = Pout/0.85 : Tin = (Tout x 700)/(0.85 x 140) = 125 ft-lbs

Thusly, with a required 125 ft-lbs input you can accomplish that with any number of sprockets. With a 2' diameter sprocket - you will require 125 lbs.

You will need to work out/maximize per your requirements. Obviously the greater reduction (increase) in the gearbox will lead to different "lengths of run" for your weight. You need to play with the numbers and optimize per what your free source of energy will allow you to lift back up, what kind of run time you need, ......

................ you probably will want a higher reduction gearbox as well.

Because the above numbers, with an input rpm of 140 will require a free fall distance of 140 x pi x 2' = 880' for a run time of 1 minute.

To just play a little more with the numbers:

Use a 100:1 gearbox (80% efficiency because the higher the reduction the greater the losses)

Input speed = 7 rpm.

Pin = Pout/0.8 : Tin = (Tout x 700)/(0.8 x 7) = 2,675 ft-lbs.

Use a sprocket of 5' diameter; you require a weight of 1070 lbs.

Free fall distance:

7 rpm x pi x 5' = 110 feet required for one minute duration.

and so.. please forgive me my inabilities to translate engineer-speak but i am not schooled in these disciplines- i am however learning as i go- my questions now are; is it feasible to design a functioning machine within these parameters; that if the total fall of the weight is 10 ft. and it's fall is a steady rate of 12 inches per min. is it possible to engineer the gearing to produce 2hp and reduce it to 700 rpm's- what about using larger sprocket gear components- thanx for your interest, jaxon