Need help in design a reel drive system.

[sungs88]

Hi, I'm new in mechanical engineering. I recently got a project to design a reel.

My reel diameter is 1.4 meter
Reel core diameter is 0.75 meter
total weight of reel with wire is 5,000kg
It need to rotate at speed 100 rpm which require not more than 10 second to reach this speed.
Motor range from 4-9.5 hp & torque 10-34 nm

I have problem with calculating the torque and power require to rotate the reel. And how to choose the correct motor and sprocket size.

Thanks for help.

 

[GregLocock]

So what have you worked out so far?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[sungs88]

i have try out calculating the moment of inertia which is 1260kg/m2 and angular acceleration is 10.47 rad/s

From above give torque 13192 Nm.

The answer i get is too much bigger than what my motor can drive, even with a big sprocket.

Did i miss out something in my calculation?
Assume bearing friction factor and other factor not yet consider.

 

[GregLocock]

you've got the wrong units for angular acceleration

yes I imagine accelerating 5 tonnes with a 5hp motor might take a bit of gearing.

As a quick check to see if it si possible I'd work out the KE after 10seconds, and see if the engine can provide enough power in 10 seconds to reach this.

Energy methods are typically easier than force methods for scoping projects, but detail design requires both.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[antmann2005]

i calculated 180 hp is that right?

 

[GregLocock]

No it isn't.

Incidentally the units for J are wrong, or at least where I come from / is a divisor.

The acceleration figure given is wrong numerically and in units, that's actually the final speed, not the acceleration.

I get that you need an /average/ power output of 10 hp, and that the OP's torque estimate is wrong by an order of magnitude.

so basically the only thing the OP managed to get right is that he needs a big sprocket.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?