DC motor specifications for moving heavy load.

[tshaffer]

I need help getting the specs for a DC motor that will move 2000lbs at 10 miles per hour max. Would prefer to be 48v or less for space requirements. Also would a deep cycle battery be best for this application or would a series of smaller batteries like LIPOs be better? I have also seen people use three phase motors with batteries but I am not sure if this is a viable option as this probably requires special controllers and more complicated components.

 

[Skogsgurra]

Lifting or just movin?

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[tshaffer]

Just moving. Also we are looking at using a right angle worm gear box with up to 100:1 speed reduction. It will also be on 15” diameter tires.

 

[itsmoked]

You've got limited solutions for that kind of weight.

1) Stack up enough batteries to get you 90VDC and use a common 90VDC motor/gearbox and an off-the-shelf SCR speed controller board.

or

2) Use the appropriate number of batteries to get you about 325V and feed that into any VFD so you can run a standard 230Vac induction motor. The batteries can be the typical 7Ahr lead acid batteries in series.

The major issue with either of those solutions is charging the batteries as neither will be serviced by any 'normal' charger.

or

3) Lay hands on a used electric pallet jack and carefully tear it apart using all of its controls, the motor, gearbox, battery, and charger as the motive power for your thing. Use chain or belt drive to match the speed you need.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Skogsgurra]

Then we need an estimate about the force needed to move the thing. Lifting 2000 lbs is a no-brainer. But moving is another thing. If it is sliding (which it obviously is not) then we need a coefficient of friction. But, this one is placed on a carriage, so one could assume less friction. Let's say one tenth of the weight.

You then need 200 pound-force, which is equal to around 1000 newton (not new ton, Newton.

Speed: 10 miles per hour is around 16000 m/h or 4.5 m/second

Net power will then be 1000*4,5=4500 W or 4,5 kW

You will probably have something like 50% efficiency in a work gear. Could be better. So, at 50% and assumed roll friction 10%, you need a 4,5 kW motor. Or 6 HP.

Wheel diameters and gear ratio is your specialty. So I don't even try to get it right. But the motor size will be in the 5-6 HP range. Under the assumptions given.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[Skogsgurra]

Of course, the HP should be doubled at 50% worm gear efficiency. So, you end up with a rather large motor. 10 - 12 HP.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[waross]

Start Googling the specs for golf carts. The cart may not be suitable but the motor, controls, and battery capacity should be close to what you need.

Bill
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"Why not the best?"
Jimmy Carter