This discussion focuses on evaluating motor specifications for a conveyor system designed to move panels at a speed of 7 meters per minute. Key considerations include calculating the necessary torque and RPM for the conveyor input shaft, factoring in resistance due to friction and the weight of the panels. The motor in question has an output torque of 1000 Nm with a 137:1 gear reduction, necessitating a final output torque of 137,000 Nm. Participants emphasize the importance of determining the motor size constant (Km) and using formulas such as P=Fv to assess power requirements.
PREREQUISITESMechanical engineers, conveyor system designers, and anyone involved in the selection and optimization of motors for material handling applications.
Sorry I forgot to mention that I got the 70 mm from the shaft coming out the motor, the one you have shown is the sprocket that moves the conveyor belt, I did this because @jrmichler mentioned to measure the rpm coming OUT the motorDevin-M said:Are you sure this part’s diameter is 70mm (2.76in) and not 70cm (27.5in or 2.2ft)?
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Thank you so much!jrmichler said:That's the same that I get assuming 10 meters per minute and a 70 mm diameter conveyor drive roll. The next step is:
Another way to get the drive torque is to place the maximum load on the conveyor, wrap a long string around the drive roll, and pull the string using a spring scale. From the force to move the conveyor belt, and the radius of the drive roll (35 mm), you calculate the drive torque. Multiply the measured drive torque by a safety factor of 2 to 3 to get the design drive torque.
Now calculate the power to run the conveyor from the design drive torque and RPM (45.5 RPM). After the torque and power are well understood, then we can start to size the motor and reducer.
If the sprocket that moves the conveyor is 702mm this changes everything.oho11 said:Sorry I forgot to mention that I got the 70 mm from the shaft coming out the motor, the one you have shown is the sprocket that moves the conveyor belt, I did this because @jrmichler mentioned to measure the rpm coming OUT the motor
I have shows how the system goes from the motor, to a sprocket moving another sprocket with the same amount of teeth, which moves that bigger sprocket. I just want to know if the motor I have specified is enough for my use, if not I will need a bigger motor obviously.Devin-M said:If the sprocket that moves the conveyor is 702mm this changes everything.
If the sprocket that moves the conveyor is 702mm instead of 70mm, the motor will need to turn 10x slower and output 10x as much torque.oho11 said:The reason for my post is that I don't really understand how torques and forces are transferred in a sprocket system, when you say it changes everything what do you mean exactly?
So logically speaking motor wouldn't be enough right? Since as I mentioned the 70 mm is the shaft coming out the motor which turns the sprocket that is 234 mm, the 234 mm sprocket turns another 234 mm sprocket which is connected to the 702 mm you mentioned by a shaft (as shown in my drawing), so now what I get is that I need a motor with a low rpm and a high torque?Devin-M said:If the sprocket that moves the conveyor is 702mm instead of 70mm, the motor will need to turn 10x slower and output 10x as much torque.
Or a greater reduction ratio in the gearbox.oho11 said:so now what I get is that I need a motor with a low rpm and a high torque?
So instead of 137:1 it would need to be more than 137 right?Baluncore said:Or a greater reduction ratio in the gearbox.
Rapistan Demag are the pros at this. I used to be a conveyor mechanic at a distribution center with 30 miles of conveyor belts. Once you find your max load allowance don't forget a overcurrent circuit to shutoff motor.oho11 said:Thank you so much I will definitely look into this as I didn't think about this part!
But how would I be able to apply this to my problem after I find the motor constant?
I used to work on Rapistan Demag systems. Pretty straight forward. He can get specs he needs for loads requiredMillGuy said:Do you have a Machinery's Handbook? If not, I highly recommend you get one. It has virtually every thing you would need to know about any sort of mechanical application. A truly invaluable resource. We refer to it as the Bible in my industry. The standard version is nice and compact, but the larger version is easier to read.
https://books.industrialpress.com/machinery-handbook/
A transmission gearboxoho11 said:So logically speaking motor wouldn't be enough right? Since as I mentioned the 70 mm is the shaft coming out the motor which turns the sprocket that is 234 mm, the 234 mm sprocket turns another 234 mm sprocket which is connected to the 702 mm you mentioned by a shaft (as shown in my drawing), so now what I get is that I need a motor with a low rpm and a high torque?