AC Motor , Hydraulic Motor or DC Motor

I was reading a post “ AC Motor instead of DC Motor” dated Sept.22nd.
Thanks for posting this question. I am in the same situation . I am looking
to push 11 columns of brick across “Free Rolling” conveyor rollers, 2.5” in
dia. Each column as 100 brick in it. Each brick weighs 4.5 lbs. , so each column
would weigh 450 lbs x 11 columns = 4,950 lbs. I roughly figured it would take
18,562 in./lb. torque to move this.

Because I am limited with space I was thinking about using…..
Hydraulic Motor , DC Motor , or a AC Motor. With a AC Gearmotor, I
am concerned that at a standstill , the motor will never be able to produce the needed torque. I was looking at a Sumitomo Cyclo 6000 Gearmotor
Output Speed 34.3 rpm Output Torque 25,700 in./lbs


Am I looking at this all wrong ? Do you think I should go with Hydraulic ?

Thanks so much for your input.

You'd better sketch your pusher - I can't see how you can calculate a torque figure without stating the acceleration required for your load.

just to put the cat amongst the pigeons, talk to a servo motor supplier.
they can be very compettive in price and may be cheaper to control

you failed to mention the following:
area covered by the bricks.
height of brick stack.
pallet the bricks are sitting on.
length of conveyor.
conveyor speed.
number of zones - individual, accumulated zones.
type of conveyor - chain driven, belt driven, zone accumulation.

each must be answered before you get to sizing the motor and required torque.

i would discuss the application with your local conveyor distributor.

regards,
james

Any of the four choices can be made to work if engineered properly.


I usually think of hydraulics when I'm concerned with power density. A hydraulic motor is much smaller physically than any electric motor of the same hp.

You can get quite high stall torques from AC motors, particularly if you use Design D or such instead of the typical Design B. VFDs can help with this. Work with your motor supplier on this.

I don't know much about DC or servos.

Duty cycle is also important

If the process is continuous then a DC or AC motor may be the best way to go but if the duty cycle is low a hydraulic motor may be best because a small motor can be used to charge an accumulator that can store energy. DC or AC motors need to be sized for peak loads.

There are some high torque, low speed DC motors available that may not need a gear box. We would need to know more about the system to know what is right for you.