# Thread: fundamental calculations - explanation

1. ## fundamental calculations - explanation

Hi,
that's my first post here.

First of all  I do not want to ask someone to calculate something for me.
I did my best (I hope correctly)  can you briefly check it and answer my additional questions? I am especially interested in these questions  I always have some doubts during calculations.
Ok, so I need to roughly calculate carousel storage motor parameters.
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I am assuming that only 5 of boxes on one side will be loaded with 200 kg. This is the worst case.
Imagine I want to lift the lowest one up to 6 meters in lets say 30 seconds.
W= mgh= (5*200 kg) * 10 m/s^2 * 6 m = 60000J = 60 kJ
P= W/t = 60000 J/30 s = 2000 W = 2 kW <- required motor power

1) There is a gear in my sketch  does this gear has any influence to formulas for power used above?
2) By the way  if all boxes will be loaded to max can it be calculated like a lift with counterweight?
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Now lets calculate a torque_motor and speed  it seems that tutorial example is the same:
so:
so torque_motor = 10000N * 0,5m (more or less) = 5000 Nm
3) This is a minimum of course  how much additional percentage do you suggest to add considering belt efficiency etc.?
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speed (0,2m/sec)
rps_gear2 * 2 * pi * radius_2 = velocity_weight -> rps_gear2 = velocity_weight / (2 * pi * radius_2)
so
rps_motor = velocity_weight / (2 * pi * radius_1)

4) BUT NOW PLEASE NOTICE that there is no radius_2 in both of these equations (torque and speed)! So whats the reason of this gear (bigger pulley)?... maybe equations are in the fact are not ok?

5) By the way  if torque and speed are given now, isnt it natural that there must be a motor power which is combined with this parameters  on the other hand  was it required to determine power at the beginning of this post?
6) Any other tips for this application?

Thanks for anyone who will support me a little bit.  Reply With Quote

2. excuse me I´m trying translate your question. I would know the procediment step for step and your objetive. are you designing this machine? so. you are calculating the dimensional and dinamic parameter to motor selection. I belive that can support you but need know the procediment that you is calculate.  Reply With Quote

gears 