Determining lLfting Capacity of motor/gearbox

[tbrereton1]

Hi,

I don't have a background in mechanical engineering however I need to determine the lifting capacity of an existing motor in a roof space so I can design/upgrade the supporting structure and pulley system accordingly.

I have contacted the manufacturer, Varvel (Italian based company), and they sent through the following details:

"Description of the entire unit is STA63/60 ratio 630/1 (6.3x100) output torque 122 Nm
and efficiency 0.35 - max input power for SF1.0 is 0.08 kW."

The radius of the pulley/drum is 0.15 m.

It is currently lifting approximately 150 kg (1.5 kN).

I assumed the lifting capacity to be output torque/radius of pulley = 0.8 kN but that is clearly not correct.

Any help would be greatly appreciated!

Thanks.

 

[tbrereton1]

Photo of unit

 

[BrianE22]

I get the same numbers you got - a little over 1/2 of what it is currently lifting (83 kg)

 

[tbrereton1]

Thanks for your response Brian.

But does the gearbox alter the load capacity?
Also would a tong test help determine the maximum load?

 

[BrianE22]

I assumed the torque rating they gave was that of the output of the gearbox. If it's of the motor then yes, the gearbox gear ratio changes the output torque. Although the gearbox ratio they gave, 630:1, still gives the wrong number for output torque. Are you sure the winch isn't currently being overloaded?

I don't know what a "tong" test is.

I'm too lazy to check the numbers right now but you should do this check:

Output power (of the gearbox) = input power (of the motor) x efficiency.

 

[3DDave]

Does this lift directly or does it use a lifting block with one or more pulleys?

 

[mfgenggear]

I believe the OP needs to get professional help. and not design some from the net.