Re: How To Calculate Total Mass Or Load Of Conveyor For Load To…
Hello,
For conveyor (or any machine), one has to find operational resistance (sum of all resistances to make the machine work at steady speed). This resistance multiplied by velocity divided by 1000 will give kW (use appropriate units in formula).
If you want to find load torque with respect to motor shaft, the steps are as below. The load torque is always understood as resistance torque.
Load torque with respect to drive pulley periphery = (Aforesaid total resistance) x (Drive pulley radius)
Load torque with respect to motor shaft = (Aforesaid torque) divided by {(Gear box ratio) x (Drive efficiency as a fraction of 1)}.
Conveyor is composed of linear motion and rotary motion components. Their overall equivalent moment of inertia (mksquare) value is calculated to tackle with start and stop situation as a rotary motion (i.e. using rotary motion formulae).
Alternatively, all components can be converted to equivalent linear moving mass to tackle with start and stop situation, as linear motion.
Refer conveyor literature books of your choice to know about above. These cannot be narrated here.
Your query implies some confusion about resistance and mass (weight). Its clarification is as below:
A car could be weighing about 1000 kg, but its resistance to motion is different. It may be just 40 to 50 kg and 2 persons can make it move / shift. Its mass will have sharp influence during starting (acceleration) and stoppage (deceleration). The average car with only driver will be very agile during speeding up and stoppage, but will be comparatively somewhat sluggish when fully loaded.
Ishwar G. Mulani
Author of Book: Engineering Science And Application Design For Belt Conveyors (new print November, 2012)
Author of Book: Belt Feeder Design And Hopper Bin Silo
Advisor / Consultant for Bulk Material Handling System & Issues.
Pune, India.
Tel.: 0091 (0)20 25871916
Email: conveyor.ishwar.mulani@gmail.com
Website: www.conveyor.ishwarmulani.com ■
Pulling Force Calculation
ISHWAR SIR,
hi i am sagar kashid from pune
I have doubt in pulling force calculation of drive roller for modular conveyor
in modular conveyor to calculate force required for pulling belt & product we use following formula
F=(Mp+Mb)*L*Fbw*9.81 Newton
where
F= pulling force in Newton
Mp- total product weight of product in kg
Mb-total weight of belt in kg
Fbw :- coefficient of friction between belt & wearstrip
if
Mp:-20kg
Mb:-15 kg
Fbw :-0.18
then
F=(20+15)*.18*9.81
F=61 N
but if i assumed that there is no friction then my force will come =(20+15)*9.81 =343 N
here i have confusion that why there is so much difference is coming in force if i have considered friction & if friction ignored.
Normally frictional force should be add into weight of product & weight of belt.
another one question, why we are not considering coefficient of friction between product & belt while calculation pulling force. ■
How to Calculate Total Mass or Load of Conveyor for Load Torque Calculation?
I want to select a motor for a conveyor or machine , for Load torque calculation, i need the weight of the parts which has to move by motor.
Now the problem is that ,can i simply take full weight of all parts which has to move or carry?
or
is there is any specific method to take weight of all parts like chain, shaft, belts ?
for example like:
if there is shaft with pulleys on two pillow blocks - the total weight is around 20 kg ,but in assembled condition it can be rotated with less force.
Please Help me for this problem ..
Thanks
AD ■