mild

[AlberTz]

Bye!
I wanted to ask for advice.
I am designing a lever structure, in which I have to lift a very high load, with a small power arm. How can I avoid taking a huge engine? Besides, having to lift about 100 kg with an arm of about 150 mm, I get a disproportionate couple of motions....
are there very tactical precarious systems? or something?
Thank you! ! ! ! !

 

[MBT]

so, there is no answer.. .
Throw down a pattern and discuss it!

I don't understand what you mean, what is the power arm and what you mean by very tactical preload. . .

 

[Fulvio Romano]

but are the 100kg load "very high"?
Do you take care of watchmaking?

Would the disproportionate couple be? 15nm? that with a 1:5 reducer become 3nm?
at this point the engine is huge, you can't accommodate it in the case of a watch...

Or maybe I missed something?

 

[gerod]

I'm accusing the illustrious ones who anticipated me.
We need a more precise scheme in hypotheses.
Thank you.

 

[AlberTz]

Therefore....the load to be lifted, which weighs about 100kg, is the red one, connected to the long rod, which flows in the lower part (length about 300 mm).
The engine is the blue one. making quick trigonometry accounts, and multiplying by the smaller arm (the one that goes from the motor to the black zipper), which measures about 150 mm, I get a pair of about 3000 nm, which for what concerns me is too much.
Now:
- I've done a few things.
-I need an alternative solution

I know only that I have to lift large loads in very little space, with the use of electric motors (possibly small).

by tactical precarigues I intend to add a precarious that helps me to use less couple of motions... .

 

[meccanicamg]

Therefore....the load to be lifted, which weighs about 100kg, is the red one, connected to the long rod, which flows in the lower part (length about 300 mm).
The engine is the blue one. making quick trigonometry accounts, and multiplying by the smaller arm (the one that goes from the motor to the black zipper), which measures about 150 mm, I get a pair of about 3000 nm, which for what concerns me is too much.
Now:
- I've done a few things.
-I need an alternative solution

I know only that I have to lift large loads in very little space, with the use of electric motors (possibly small).

by tactical precarigues I intend to add a precarious that helps me to use less couple of motions... .

missing angles and races, because if you take the 300 mm rod and put it horizontal (biella) you will have the 150 mm handle with max orthogonal arm to the weight of 1000n but mechanically impossible because the biella is too short.

check the calculations you made. . .

 

[AlberTz]

missing angles and races, because if you take the 300 mm rod and put it horizontal (biella) you will have the 150 mm handle with max orthogonal arm to the weight of 1000n but mechanically impossible because the biella is too short.

check the calculations you made. . .

Right!
I mean in the critical condition, that is almost horizontal (in the horizontal position will never arrive).
vertical I have less problems.... .

 

[gerod]

Yes, but you put some odds done well so we get better.
Or not?

 

[meccanicamg]

I solved you except friction and with approximate angle very great exercise +/- 5° and I attach the results of the simulator.

I applied 1000 n and the maximum torque is 300 n*m in horizontal position.

I attach you the main conditions of your structure that is nothing but a biella with biella baricentro on the side
counterweight. ..vabbeh lucubration not useful:finger:

the angle is measured during lifting in positive clockwise

 

[AlberTz]

this system rises and descends according to a logic dictated by external signals. the biella holds on one side the weight and on the other is bound to a cart. in the middle, a zipper connects her to the crank.

I believe I have provided all the specifications:
the weight varies the height from 5 mm to 250 mm compared to the zero point (identified with the blue motor).
the most critical condition is when the weight is very low, because the lever is disadvantageous, so with alpha about 85 degrees.
at that point, with the weight force of the load equal to 1000 n, I obtain a perpendicular force to the handle of 150 mm high-> the torque that such force generates on the engine pin is about 3000nm.

I just hope I've made a mistake, but I've dealt with them well... .
help...

 

[AlberTz]

I solved you except friction and with approximate angle very great exercise +/- 5° and I attach the results of the simulator.

I applied 1000 n and the maximum torque is 300 n*m in horizontal position.

I attach you the main conditions of your structure that is nothing but a biella with biella baricentro on the counterweight side. ..vabbeh lucubration not useful:finger:

Thanks mechanicalmg!! !
is exactly the same result to me as well....
the problem though is if you know an alternative to using a less powerful engine......

 

[meccanicamg]

Thanks mechanicalmg!! !
is exactly the same result to me as well....
the problem though is if you know an alternative to using a less powerful engine......

If you get the same, why do you say a thousand newtons with three thousand newtons per metre? the zeros count and our numerical system is positional!!! I tell you a thousand newtons of strength and three hundred newtons per meter we pair.

If you want a system you start or lighten forces you can put a fixed counterweight or rope depending on where you put it.

 

[AlberTz]

in fact I wanted to write 300, and not 3000..... I missed the finger o_o
cmq confirm your data!
the idea of the counterweight I like, I just have to understand how to place it (I have little space and I can not weigh too much the structure).

Thanks again!!! !

 

[meccanicamg]

in fact I wanted to write 300, and not 3000..... I missed the finger o_o
cmq confirm your data!
the idea of the counterweight I like, I just have to understand how to place it (I have little space and I can not weigh too much the structure).

Thanks again!!! !

not knowing where you have space and how, I tried to put a counterweight to the rotation on the motor shaft, so as to balance, but with 200n and 200 mm of arm you can not do miracles. if you have enough space you can see to enlarge weight or arm.
otherwise there is to look if there is the possibility to put some spring of repulsion on the cart to increase the thrust.

I'll raise you with counterweight.

 

[Fulvio Romano]

but a hydraulic cylinder in the fulcrum?

 

[AlberTz]

Thanks mechanicalmg!
Now I try to see if I can integrate your solution.
specifications are very strict. I'll assess the alternatives well.
cmq yet thank you!!! ! ! !
x Roman lightning: no hydraulics....only electric motors!

 

[Fulvio Romano]

x Roman lightning: no hydraulics....only electric motors!

So...electric linear actuator?

 

[AlberTz]

Also that is a possible road, I must see the costs....
In short, it's a pretty busy project

 

[zeffiro62]

trapeze screw with motor between the fulcrum and the blue motor

 

[PierArg]

mmmmmmmmm... something doesn't come back to me.
I'm sorry the question, but have you made such a system? if yes, it really works?