## Conveyor Torque

## Conveyor Torque

(OP)

A company called the other day with a question about their conveyor. My company did not build the conveyor but did supply the gearbox. The conveyor is 8 feet long, and 4 feet wide, it is level and transports castings to the grinding department of a foundry. The motor they are using is a 4 pole 5HP motor, assuming at 60Hz. I was told the castings get "dumped" onto this conveyor which is always turning, so there is a bit of a shock load. The foundry wants to be able to move 3000lbs of castings on this conveyor, however when they put the load on the conveyor the motor trips out. The gearbox that is on their conveyor is rated for 9000in-lbs with a 5HP motor and 29 rpm. The conveyor shaft that is connected to the gearbox is 11 inches in diameter.

I used an equation that I found but had to convert the values to metric and then back to standard.

The force is MU * Mass* Gravity, where MU is 0.5, the 3000lbs is converted to Newtons:13344.66 Newtons, gravity is 9.81

So F=0.5*13344.66*9.81

Force = 65455.6Newtons

Torque = 65455.6N * 0.2794m : the 0.2794 is the 11 inch shaft converted to meters

Torque = 18288.3Nm; 161865.2in-lbs

Am I on the right path with this? If so the current gearbox is greatly undersized.

Thanks for the help it is greatly appreciated.

I used an equation that I found but had to convert the values to metric and then back to standard.

The force is MU * Mass* Gravity, where MU is 0.5, the 3000lbs is converted to Newtons:13344.66 Newtons, gravity is 9.81

So F=0.5*13344.66*9.81

Force = 65455.6Newtons

Torque = 65455.6N * 0.2794m : the 0.2794 is the 11 inch shaft converted to meters

Torque = 18288.3Nm; 161865.2in-lbs

Am I on the right path with this? If so the current gearbox is greatly undersized.

Thanks for the help it is greatly appreciated.

## RE: Conveyor Torque

What you may need to look at is the acceleration and power requirements, not torque/force. If they put a ramp to cause the castings to meet the belt at the belt speed there would be no acceleration, but if they just drop them and expect the belt to accelerate the castings, then you need to decide how fast they accelerate, et al.

Periodic impact systems often have large flywheels to provide the instantaneous power rather than building a gearbox/motor to do so.

## RE: Conveyor Torque

Well the customer got back to me, now it seems everything has changed. The roller diameter is now 14 inches, width is 4 feet, and has a length of 10 feet, zero angle, and the conveyor has to handle 10000lbs. It is a level conveyor and the castings will not be any acceleration.

Does anyone have equations to help solve for this? I have been searching the internet for them but so far no luck.

Thanks in advance to those who reply.

## RE: Conveyor Torque

## RE: Conveyor Torque

http://rtodds-eng.com/Published%20Articles/6th%20E...

But, if changing the spec., can they ask you (as the gearbox OEM) to supply their conveyor design??

However, for the sizing of a conveyor drive there's at least to be considered:

roller and / or pulley dia & bearings

belt type & strength

load characteristics (throughput, type of loading)

a sketch with (sufficient) dimensions

then

drive characteristics (i, J, n) from the applicable range of options, with required P and P-rating of drivetrain to be the design output.

So, why not come back on the original conveyor designer & supplier? Due to the higherloading, at least for the belt (if it is a belt) there should be re-consideration of its loadbering capac.

Regards

Roland Heilmann

Lpz FRG