- #1
bauereri
- 1
- 0
Hello,
I need to size a motor for the following conditions,and I have managed to completely confuse myself:
Motor will turn a hollow cylinder
Cylinder mass = 10000kg
radius = 0.759m
acceleration = 0.25m/sec/sec
Cylinder speed = 19 rpm
I've been calulating the torque by:
T = (I * a) where
I = moment of inertia
a = acceleration
and the horsepower by
HP = (n * T) / 5252 where
n = cylinder RPM
T = torque
I can do all of this fine and the answer come out to around 2hp. However, I am confused about how adding a gearbox to this arrangement will affect the HP needed. I don't see anything in any of these formulas that take into account gear ratio. It seesm to me that if I were to add a significant gear reduction, I should be able to use a much smaller motor.
Where am I going wrong?
Thanks,
Eric
I need to size a motor for the following conditions,and I have managed to completely confuse myself:
Motor will turn a hollow cylinder
Cylinder mass = 10000kg
radius = 0.759m
acceleration = 0.25m/sec/sec
Cylinder speed = 19 rpm
I've been calulating the torque by:
T = (I * a) where
I = moment of inertia
a = acceleration
and the horsepower by
HP = (n * T) / 5252 where
n = cylinder RPM
T = torque
I can do all of this fine and the answer come out to around 2hp. However, I am confused about how adding a gearbox to this arrangement will affect the HP needed. I don't see anything in any of these formulas that take into account gear ratio. It seesm to me that if I were to add a significant gear reduction, I should be able to use a much smaller motor.
Where am I going wrong?
Thanks,
Eric