Hi everyone I'm student and I have project in design of gearbox I select the pump jack Now I need some equation to calculate 1..Power output of pump to determine the power of motor using the efficiency of gearbox and after that to select suitable motor and rpm of it 2..torque Please explain to me with equations how to calculate the above requires Best regards

I think your question is a bit wrong and uncomplete. What is the aim of your exercise? Do you need to calculate the absorbed power of the pump? Or do you need to calculate the motor power?