Motor Selection

[rogerb01]

I am trying to calculate what the power and torque requiremnt is for a 3 phase AC Motor which is then to be fitted with a gear box for the following application.
I am moving a platform that weights 4000kg
The method of movement is via steel flanged wheels the effective diameter of the castors is 250mm, these are running on steel rails
The speed the platform is required to move at is 1 m/min approx.
Can anyone please help me with this matter

 

[Feg]

Hi Roger,

With the limited info you have given, i think 1.5Kw at 76 rpm will do the trick, I am basing my calculations on a shaft diameter of 30mm with ball bearings on the wheels.

Co-efficients for calculation:
coeff. of friction at wheel brg. : 0.005
coeff. of friction at wheel flange : 0.003
material of wheel/track : steel/steel
rolling friction lever f (m): 0.0005
friction wheel/track : 0.15

Hope this helps.

Feg

 

[rogerb01]

Thanks for the info. I am using a gearbox with this because it travelling so slow. Could you advise me on how to calculate what ratio gearbox I'd need and what my torque requirement at the output shaft on the motor and gearbox would be.

Thanks in advance for your help

 

[davidbeach]

What is the application, sounds a lot like a school problem.

 

[waross]

If this s a real problem, look at the largest gap between the rail ends on a cold day. double or quadruple it. Now put two wheels in the gaps and calculate the force required to lift off. That will probably be your worst case load.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[rogerb01]

Yeah this is a real problem not in a school at the 380 Factory in Airbus to be precise. Thanks for the help

 

[Feg]

My selection was based on using a right angle worm geared motor driving the axle of one of the wheels ie direct drive, speed-rpm 76, ratio 1420 (motor rpm) / 76 = 18.68/1. if you are concerned about crabing you could split the drives into 2, 1 per side

 

[rogerb01]

CHEERS FEG,
THE SPEED AT THE OUTPUT SHAFT OF THE GEARBOX SEEMS A LITTLE FAST GIVEN THAT THIS PLATFORM IS ONLY TRAVELLING AT 1 METER PER MINUTE. CAN YOU CLARIFY.
CHEERS