Understanding Torque: Misalignment & Bending Shafts

[Ask1122]

Hi all, today our lecturer has told us something which i do not really understand, and i was hoping if someone can clear up the issue for me.

The following is what was said: we have a motor and we have a pump, the pump and motor shaft is joined by a coupling. If there is a misalignment between the pump and the motor shaft, the 'TORQUE' will causes the pump shaft to bend. Now this is what i don't understand, i always think of torque as a twisting force, how can a twisting force 'bend' something? In order to 'bend' the pump shaft, wouldn't you require a 'bending force' (which i thought it was the force exerted by the bearings which causes the pump shaft to bend when it is mis-aligned)? I think i am missing a basic concept on torque here, it will be really helpful if someone can clarify for me!

And secondly, if the pump and motor shaft is misaligned, wouldn't there be bending shafts for both the motor AND the pump? Why is it only the pump shaft that will be bend??

Sorry for my elementary questions, but i just can't seem to grasp this concept well. Thank you for the helps guys!

 

[LightHero]

Torque is a twisting force, and it can cause bending when applied to an object. When the pump and motor shaft are misaligned, the torque created by the motor will cause the pump shaft to twist and bend, while the motor shaft will remain relatively unaffected. This is because the motor shaft is connected to the motor, which is held in place by the motor mounts, while the pump shaft is connected to the pump, which is not held in place and therefore is more susceptible to the twisting force of the torque. So basically, the misalignment causes the torque to be applied unevenly on the two shafts, resulting in the pump shaft bending while the motor shaft remains relatively unaffected.

 

[astrokreng]

Torque is indeed a twisting force, but it can also cause bending in certain situations. In this case, the torque from the motor is being transmitted through the coupling to the pump shaft. If the pump and motor shafts are not perfectly aligned, the torque will not be evenly distributed along the length of the pump shaft. This uneven distribution can cause bending in the shaft, as the torque is trying to twist the shaft in one direction, but the misalignment is preventing it from doing so smoothly. This creates a bending force on the pump shaft, which can cause it to bend.

To answer your second question, yes, there can be bending in both the motor and pump shafts if they are misaligned. However, the pump shaft is typically longer and thinner than the motor shaft, making it more susceptible to bending. Additionally, the pump shaft is also under more stress and strain due to the pumping action, which can make it more prone to bending. This is why the pump shaft may experience more bending than the motor shaft in this situation.

I hope this helps clarify the concept of torque and how it can cause bending in certain situations. Remember, torque is a force that can cause both twisting and bending, depending on the circumstances. Keep asking questions and seeking understanding, as that is the essence of being a scientist.