- #1

teage

- 7

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I am designing (homework) a winch drum and am having a brain fart. i am trying to find the power required to maintain a constant velocity.

i have figured out that the torque required to lift the mass is in 3 parts:

1. torque to accelerate the drum = 241 N.m

2. torque required to hold the mass = 3531 N.m

3. torque required to accelerate the mass = 540 N.m

so the torque required to accelerate everything is 4312 N.m

power required to accelerate is 28.75 Kw

now i need to find the power to maintain a constant 4 m/s or 6 2/3 rad/sec with a drum diameter of 1.2m. i have found N to be 64rpm but I am not sure which torque to use to calculate the power.

i assume that the inertia torque can be left out along with the torque to hold the weight of the mass.

If so i am left with P=3.6Kw to maintain velocity. it doesn't seem to be enough considering the starting torque is 28.75Kw.

assume no friction.

Is this right?

Thanks