Gear Box Ratio, Speed and Torque

Any idea of the power needed?

Your motor is powered by an hydraulic group?

A gear ratio of 1:4 doesn't really need a gearbox, but can be easily done with chain sprockets or gears.

Your couple will be quadrupled (approx.) at the biggest wheel shaft, considered you'll put the small one on the motor and use it in high speed mode.

Not enough information there to work out gear strength. Search for "Lewis formula" which is used to calculate gear tooth strength.

Sounds a bit fast for a chain drive.

Torque is inverse of speed. Speed step up equals torque decrease, minus gear/sprocket train power losses.

Better to first see about reducing the motor drive to get 1400R, instead of conversion. Get torque/speed data for the motor vs hydraulic drive power. It probably can be reduced, but "how much torque will it produce" is the question.

Thank for your reply, So not taking into account any losses, are you saying very basically that I multiply my input torque by my gear ratio ?

If so that was staring me in the face the hole time, cheers.

So now I know this how would I work out what sized gears or sprocket diameter I need to put into my gearbox.

At this stage I am not interested in the strength as such, just the diameters for the input and output gears unless that is needed to calculate the diameters. Cheers Dan