Runing Generator by hydralic power

Yes
...You can use as many daft machines in series as like, each one losing power as it's efficiency will be less than 100%.

If you are starting with an electric motor and ending with a generator it is a bit pointless as you are just wating power.

It would make sense if you went from a hydraulic motor/turbine straight to a generator.

Del

Reason is am trying to avoid running it with an engine.

say starting with e.g 10hp electric motor + the right size of hydraulic pump maybe from a

dump truck + through a variator actuator then generator say 100kva?

if not what is the load on a 500kva generator on the fly wheel torque?

Well, 10 HP is much less than 100 kVA, regardless of the size of the hydraulic motor. So, HUH?

In a nutshell, no. What you're proposing is yet another over-unity idea. Can it be done? Yes, but you'll LOSE energy at each stage, not GAIN it.

Efficiency is often as not less priority than function.

...and function is often as not less priority than education.

Were is Jack Jersawitz when you need him. The more agro you put upon an idea the sooner it will be shot down. If I had a hydraulic arm would I not be able to get myself out of a swamp by pulling my hairs really, really hard. Oh, just shut up Ky.

PS: I have a drawing some where but I keep forgetting to post it.

You're expecting to get an output of over 100kVA from a 10 hp motor which has an output of approx 7.5 kVA...?

Arrrggggghhhh

The actuator torque is 3,200ib-in say pressure 2,000psi speed range 1,400 rpm.

the main component is the rotative actuator i.e using a portion of electricity that is metered to run only the 10hp motor thats all .....then its the hydraulic pump that pushes the high pressure oil then runs the Actuator /Variater which in turn turns and run the generator ( use small power in the beginnig and have more electricity produced by the generator) or say what ever initial size of motor and pump is important.

think about it!

So, why not bypass the hydraulic bits and just have the motor drive the generator and then use a bit of the generator's output to drive the motor...

YES!!! free electricity - NOT!!

Why don't you think about it...!!

Here you are missing the most important part of this subject, The great work of the hydraulic oil, e.g where does power of lifting a car on a lifter found in workshops come from? yes you have an electric motor driving a pump which in turn pumps hydraulic oil in a piston and raise the weight of the vehicle right, is that not hydraulic power? now you cant say why not by pass the hydraulic system and put the motor directly,here you will need a very big motor to do the work of the smaller one which with the help of the hydraulic system boosts the system. see this drawing.

now you cant say why not by pass the hydraulic system and put the motor directly,

Well, of course you can! Given the same sized motor that currently drives the car lifter by hydraulic means, just drive a lead screw through a worm drive. So long as 'the time to do the work' is enough (gear ratio).........! In fact, there would be less mechanical inefficiency's by this means! Many car lifters work by this means!

So, the only way to rationalise using hydraulics at all would be for the benefits of 'power density' or 'flexibility'!

A hydraulic system usually suffers from about (only) an 80% efficiency, taken over the entire fluid power system.

I, for one (or like most other contributers) must be missing your point.

Please can you explain what you are trying to achieve and I'm sure we will be able to shoot holes through the idea.

If you still want a hydraulic generator, google Dynaset!

The electric motor is Only to drive the Hydraulic Pump just as you see on hydraulic press,

Car lifter,a mobile container lifter can lift sat 20 tons ,remember the argument here is using the help of hydraulic power through a specially designed rotative actuator. results use a small portion of electricity to drive the motor which will be metered BUT what the generator produces is free Power. well still i insist what is the final torque on the 100kva/200/500kva? then give me a reason as to why the hydraulic system i have mentioned wont be able to drive the generator!

i have a drawing but failed to paste it.

So you are trying to reclaim some of the energy used to lift a heavy object?

If you reclaimed 10% or so how long would it take to pay back the expense of the extra systems?

Would it be possible to use this reclaimed hydraulic pressure to charge an hydraulic accumulator, this would cut out some of the conversion losses.

You're not looking for a free lunch, just a discount.

See this web site and check out the various options on rotative actuators

http:hks-partner.com/en/products/rotary-actuators.html

maybe this could give you a hint!

if you send me your email l can send you the drawing as l have failed to paste it on this

discussion

Some cannot see the forest for all the wood that is in the way, they don't even see the trees.

Its odd that 'they' are usually correct though isn't it?

Perhaps 'they' see more than you think or know about?

Yeah!

Some people here are practising, accomplished, nay, even OLD experienced engineers, who've seen it all before.

This thread is not an original thought.

Cheers

Stu.

Been thinking about it all the way through this thread. Listen to what you're being told. The guys (girls????) have got it right.

If you can only access, though the wires, enough energy to run a 10hp motor that's all the work you're going to get out of this arrangement.

Where do you think you're going to get the extra energy to run a 100kva generator.

Depending on the power factor the power needed to run this jigger is in the order of 150hp. All things considered.

This realm is like the Government, 'you'll get nothing for nothing'. ie, No input, no output. Capice?

Are you trying to make perpetual motion?

Cheers

Stu

by means of hydraulic Pressure which is driven by the 10hp motor and then is boosted by the special rotative actuator have you hard of a concave-convex driven off through hydraulic coupling operating with hydraulic oil? say like a supercharger?ref om titano

think about it

need to see my design !!!!

Yep! Know all the words. Still won't work for you.

Cheers,

Stu

Yep. Worked on a system once where we used an electric motor to drive a pneumatic pump which drove a pneumatic motor which drove a generator. We needed to get power past slip rings carrying nerve impulses and we didn't care about waste (small system) or noise. I think the efficiency gets down to about 2% or so.

tvp45; was this a medical device? more information please perry

No its curiosity some young inventor trying to cut pollution and Cut down Power costs

These devices exist.

They are called Variable Frequency Transformer and sold by GE

The big benefit is that you can generate high power variable frequency AC power.

Typically for R&D use but the use can be much wider.

In normal applications where you need to shift the frequency of an AC power source you go with a motor - gearbox - generator system (for high power systems). when you want a variable frequency as the output the VFT from GE is a good solution.

That's true Gwen.

I read it as him wanting to increase the stored energy of his system. As you know, you'll only get out less than you put in. It's possible to store energy in an accumulator, for short (relatively) bursts of release. The brief output in a well engineered system may well

get to his goal, as stated, but the net effect is that there'll be less, in the end, than he's harvested.

If he wants to save power, he needs to turn some lights off. OOOOhhhhYYEEEAAAAARR!

Stuey,

You hit the nail: again someone who invents the fifth wheel on the car which drives the generator which on his turn drives an electric motor to power the car.

I expressively did not react on the last statement of him as others already pointed out that the efficiency goes down enormously.

See at last somebody is talking sense! here whats next?

However no body has told us what is the final torque at the flywheel of a 100kva/200kva/500kva ???

having known those fig`s then we take a next step!

Impossible to tell.

Not enough information.

What's the electrical configuration of the motor?

And which one do you want? 100? 200? 500?

Hours of calculations involved if you want accurate information, and there's no point if you don't want to be accurate.

What's the entire point of all of this?

Waste someone's time?

Stu.

At the most the amount of work or energy gotten out of this is the amount put in.

In your reference to the use of hydraulics to lift a load. It is the use of hydraulics to reduce system cost, control and improve system safety.

A good electric chain hoist would accomplish lifting the same load. Because of the many working parts of the hoist the cost will usually exceed the cost of a hydraulic system.

In making it safe brakes on the chain hoist can fail. A port reduction on the cylinder of the hydraulic system for a controlled lowering will insure a slow lowering if there is a failure.

Very well explained.

Guys i think you all misunderstood me. What i meant is you take for e.g a Generator that produces 100kva, here remove the diesel engine that drives spines it, then simulate the work of that engine with the system i have mentioned 1) the work of the Motor which is powered by the main electricity supply only runs the electric motor of 10hp that all is need on this part , then the motor drive the hydraulic pump (same as that found on damp Truck or say tippers) now this is the important part the rotative hydraulic actuator e.g (similar to what you mat find in Diesel Test benches ) here the pressure is

extent that you need a relief valve to relive the pressure,

another e.g how does a hydraulic press work? here same thing there is a motor with runs a hydraulic pump BUT remember this type of pump is less power full than that found on trucks. but still here you can press 10,000kgs when an engine drives a generator you don`t have to rave the engine to maximum but at a moderate speed of 1500 rpm or so. same thing here with the motor its rated at a particular speed that suites the right initial pressure then the Actuator mechanism builds the necessary

enough to run that same 100kva instead of using the engine.

so that is the whole issue running a Generator with hydraulic power instead of engine.

results i pay only for the power consumed by the 10hp but in return i gain 100kva free to use.

I think you misunderstood our claim: you can't generate energy out of nothing.

The point where your logic fails is the flow rate: your 10KW engine driven pump wil generate oil at 1000 MPa if you want but the flow will be very low.

The oil driven rotative actuator will need a certain amount of oil flow to realize one rotation. To have a single pole generator delivering at 50 hz you need 50 revolutions per second. Fairly easy to calculate the amount of oil needed (50x the volume/rotation)

As you know power can be written in momentum x circular speed (RPM * 2Pi) (result will be in Nm)

Attention: RPM is 60x the frequency of the grid (3000 for 50 Hz)

The rotative actuator will need a certain perssure to generate the momentum you need at a given speed.

Just check the data sheets of the potential suppliers, combine all the figures and validate your statements.

Don't mess your calculations with those funny conversion figures as used in the imperial system and you will accept my initial statement: you can't generate energy out of nothing.

Oh, for goodness sakes! What's wrong with hogsheads per fortnight as a flow rate unit? You metric people are just so smug cause you got powers of ten and we get to divide by 16, or is it 12, or 360, or 3... Say, did I ever say how much I admired Napoleon.

Funny thing: Napoleon did see the power of the metric system and just because he was French the Anglo American world does not accept it.

But it reveals in a simple un-doubtable way the relation between power, force and movement.

The imperial system needs conversion factors, sometimes these are understood as the great conspiracy of oil companies who want to prevent you from running your engine on plain water.

Read beond the last phrase and see the power of my explication, just down to earth pointing where he missed something: flow rate.

To sorta highlight the absurdity of our having a system that is different from the rest of the world... I am currently translating some drawings which were originally American, then translated to an unnamed metric country and now are coming back to America. I keep finding sheet metal dimensions accurate to 0.001 mm. Oy Vey! Nobody ever wanted that, but the conversions gave it to them anyway. I would even be willing to give up furlongs and bushels if it meant harmonizing with everybody else.

Following that logic couldn't you just substitute a 5hp lawnmower engine for the diesel?

Hey!

I've got it!

Your the guy that Douglas Adams was refering to below!

Maybe I missed the point of your question. Are you trying to build a pulsed power unit where you run, say a 5 hp motor for a long time and then get lots of W out very quickly?

I give up.

It appears that you seem to think that you can, by some magical virtue of hydraulic power, use a 10HP electric motor to drive a hydraulic pump that will turn a 100kVA generator at sufficient speed and torque to generate more electricity than you put in to the electric motor. Yet no matter how many ways in which we explain to you that you are missing some very large parts of that puzzle, you persist on asking the same foolish questions. I gae you the benefit of the doubt at first thatmaybe you were going to use the hydraulic systems as an accumulator, but it appears as though even that thought escapes you.

Expend your mental efforts on something else.

Me too!

It is though, typical of someone who has just a smattering of technical knowledge. And common sense.

Stu.

View this e.g why can a person with one hand turn a hydraulic power steering of a very

big dump truck of more than a 100 tons, is that not hydraulic power?

Remember there are bearings on each end of the generator that what we are lookig at is to drag and turn it just as that as an engine would do.

if the drag was so hard it would tilt over! may be add a kind of gear box with some ratios

to manage the rpm speed which would be rated at the same speed say 1500 rpm just as that of the same diesel engine would have done,

now lets view this:: e.g No1 take a 100kva generator complete with its engine

this generator is giving you power output of 100kva @ 1500prm.

here remove the engine off and simulate with the same generator as long as you can maintain the rate speed of 1500rpm wont it produce the same as if it were run by the engine?

if one can lift a container load with 20tons by mens of hydraulic jacks operated by a small pump using 24volts batteries i don`t get as to what is so hard to rotate the generator is the drag that heavy?

is the drag that heavy?

YES! The drag to generate 100kVA IS so heavy (as you put it). Also you have the other inherent inefficiency's such as windage and friction! As previously stated by others, you may need considerably more than even 110kVA input to get close to 100kVA output.

Accept what qualified people are taking time to explain to you. It 'aint going to work!

am back to the drawing Board!!!

I sent you a PM [personal message] yesterday, along with an explanation of how to post a picture & a link?

It's not a good idea to post email addresses on public forums, unless you like spam.

Jeeeesssz!

I've gotta give you top marks for persistence.

Stu.

have come across hydraulic jacks of 4 stand lifters run by a small simple hydraulic pump with the use of 24vots batteries and you lift a container loaded with 20 tons?

why is that possible? please elaborate!

a master/slave actuator configuration

some one send me your email so that i send you my drawing sketch as i have failed to paste it on CR4 then display it to all members to view

Try try again, repeat

True...Seen it done many times, any time you walk into a mechanics you will see this or an electric forklift.

But, this lifting action is relatively slow, this is using the incompressability of a liquid to lift a dead weight.

It is a Low Volume\High pressure pump going to a High Pressure\High Volume piston and slowly (relatively) lifting the load.

This low power over a long period of time to achieve the task.

To perform the same action to the equivelent of 1500-1800rpm for a generator, you are going to need a High Volume\High Pressure pump requiring a massive motor to turn.

Regards,
Sapper.

what if i add a gearbox ratio up build up speed?

A gearbox works by taking higher RPM and low torque and using levers (the gears) reducing RPM and increasing torque. Or the reverse, Low RPM and High Torque and converting it to Higher RPM and Lower Torque.

Think of this as a Lever: -

You can use a Small weight on a Long lever and move a Large weight a Small amount

Or

You can Use a Large weight on a Short leaver to move a Small weight a Large amount

If the Large Weight is on the Long end of the lever Nothing will happen

It the weights & lever lenghts are the same you have a balance.

Try it.. Hydraulics is just a "Flexible Lever" the same rules apply.

Regards,
Sapper.

Oh I can't stand it. I know I said I give up, but your eternal optimism intrigues me to the point of WANTING to help you understand. I am an eternal masochist I guess...

First off; "what if i add a gearbox ratio up build up speed?"

As already explained, gears increase speed while reducing torque, OR they increase torque while reducing speed, but they CANNOT increase both torque and speed. You NEED both. There is no magic box, hydraulic, mechanic or electric, that adds speed AND torque to a system like that without having it stored up, as in a battery, flywheel or accumulator. Even then, once that extra energy is depleted, it must be replaced.

Research the concept of "Moment of Inertia". Every mass at a standstill, bearings or not, requires force to make it move. Without exerting force on it, it wants to stay still. The amount of force necessary is proportional to its MASS and its center of gravity. So the larger it is, and/or the farther its center of gravity is away from the point of movement, the more force it takes to get it moving. With a cylindrical mass and rotational forces (motors and generators), the axis is the hub of the cylinder and the radius is the distance of the center of gravity. So the bigger the radius and/or the heavier the mass, the more force, or TORQUE (the unit of rotational force) is necessary to move it.

So here is an example you may understand:

Look at a bicycle wheel. It is roughly the same diameter as a car wheel. Lift up the front of your bicycle and spin the wheel. It spins fairly easily. Now jack up your car and try to spin the wheel (take it out of gear of course). It is the same diameter, but it has more mass. So it is a lot harder to make it spin is it not? Now if you take a small conveyor roller made of solid steel only 4" in diameter, but weighing the same as your car wheel, it would still be easier to make it spin. Why? Because even though it has the same mass, it has a shorter center of gravity.

Secondly, addressing your earlier example of a hydraulic lift: Yes, a small pump run by a 24VDC motor can lift tons of weight. BUT, it exchanges rotational distance (the pump motor rotor) for vertical distance (the hydraulic cylinder length). It is then still the same as having a gear ratio. Think about how many times that motor had to spin around, pumping hydraulic fluid, before it moved the tonnage even a millimeter. If the pump is spinning 1750RPM and it takes 3 minutes to lift the weight 2 feet, that pump spun 5250 times. If the pump motor rotor was 8" in circumference, that means the total distance traveled, if you stretched out that rotational distance, comes to 42,000 inches, or 3,500 feet. So you moved something 3500 feet to move something heavier by 2 feet, an effective gear ratio of 1750 to 1. What the hydraulics did for you was to keep from having one massively huge gearbox. But it did NOT accelerate that mass to the same linear speed as the motor though; it traded distance for mass.

Translating all that into your generator then, you have a small 10HP motor spinning at 1750RPM, and you want to spin a large generator rotor at 1750RPM. No matter how many gearboxes, hydraulic pumps or whiz-bang gizmos you put in between the two, it will ALWAYS take more force to spin that generator than what you have available in that motor. In fact, over 10 times as much! And on top of that, every gear box, hydraulic pump and gizmo you add is going to actually ROB power from the equation.

Could you just get a faster spinning motor? Sure! But if you had a 10HP motor that spun at 17,500RPM, the torque would be less than 1/10th what it was at 1750RPM, so you lose again.

OK, that's it, I am spent...

Gentlemen! very sorry that i din`t reason that way. Now i have realized that i was wrong

am glad that with all your help you have saved me from all the sleepless nights where you close your eyes but the brain remains searching like chasing Air!

Again thanks guys!

Vercellese

WHHHHEEEEEWWWWW!!!

Stu.

Hi Stu

It only took a year to see the light! And I thought I was a slow thinker!

Hey, Stu', give us a hoy sometime!

Brian

Yes you can.

Is it your intent to use tandem pumps to increase the flow or an here to fore unknown force to enable the rotary actuator to transfer energy at an increased dynamic?

Yup...That about says it all!!

Sapper

Vercellese,

I really don't know whether you're trying to pull our legs or not. Taking you serious I have to say that you don't have a clou about simple mechanics/fluid mechanics. In simple equations:

Torque = Power / (2 x pi x n); P=100kVA, n=1400 1/s in your case

pressure = Force / Area; This is why your hydraulic press is working!: F1/A1 = F2/A2

Work = Force x distance; This is why your hydraulic lift is working: F1 x s1 = F2 x s2

You can NOT get more energy/work/power out of a system than you put into it!

If you would understand how a chain hoist is working, you would see that your idea is not working out. In regard to your generator, an unloaded hoist is easy to work. Put a load on it, you will see that it's getting harder. Same with your generator, if you actually try to put a 100kVA load on it, the torque will exceed the capabilities of your 10hp engine. PERIOD.

The thread was really funny... huh, hehehe... tsk... tsk... tsk...

Hydraulics is just a "means" of "transmitting power... isnt it that basic energy theory is it cant be created, nor destroyed... but can be transformed.

Check about bernoulli priciple on hydraulic power transmission...