How will the final output here behave?

[seany]

TL;DR Summary

If you have multiple motors adding to a shaft via bevel gear, will the output power be just the sum?
what about RPM? What are the problems the system can suffer from? e.g. backlash

Hi

I was watching this:



How will we calculate various outputs?


1 Final toruqe?
2 RPM
3 Output shaft horsepower?

Will it just be a sum of the individual motors, or will there be other things to keep in mind?

Does the efficiency scale linearly?

What issues will appear from a setup like this? gear mesh failure? Backlash?

I would be happy towards some general pointers, and if there are some technical papers i can read

Thank you.

 

[Baluncore]

Assuming DC brush motors.
The torque output from the shaft will be the sum of the torque from all the motors.
The torque from a motor is proportional to the motor current.

The applied voltage, the back EMF from motor rotation, and the resistance of the motors, will set the operating point.

Backlash will be eliminated where two motors are opposed, with opposite currents and torque.

 

[seany]

Thank you

The applied voltage, the back EMF from motor rotation, and the resistance of the motors, will set the operating point.

How would I go on calculating those? Thank you

 

[Baluncore]

It may depend on how you power the motors, assuming a fixed DC voltage.

Operate the motor as a generator to find the back EMF volts / RPM. That will be similar to the specified unloaded RPM at specified voltage in the data sheet.
That allows you to compute the back EMF from the RPM.

Measuring the winding resistance, Rs in ohms, while turning the motor slowly by hand so you can eliminate any commutator bumps.

For a specified operating RPM, compute the back EMF and subtract it from the applied terminal voltage V.
The current in amps will be; ( V - back EMF ) / Rs.
The current will generate the torque.

You can stall the motor with a fixed torque arm, then adjust and measure the current to identify the scale factor.