Questions about friction losses in an electric motor

[Tabaristiio]

1) What is friction loss / are friction losses?

2) How can it be determined / measured / calculated / figured out?

3) How does it affect the power output (force * speed) of an electric motor when an electric motor is moving / lifting objects? Why does it have such affects?

 

[jim hardy]

What effort did you make to answer these basic questions for yourself before asking others to invest their effort ?

 

[scottdave]

In short, two sources to consider are parts rubbing against each other, and interaction of air with the moving parts.
Steve Mould has a nice video about sources of friction losses in a fidget spinner.

 

[Dr.D]

As ScottDave mentioned, windage is always present unless the motor runs in a vacuum. The other big friction source is the bearings. Even the very best bearings always have some friction.

As to how to see/measure the effect of friction, assuming we are talking about an induction motor, measure the no-load speed. With no external load, and in the absence of friction, the no-load speed would be synchronous speed. Since friction is always present, the speed difference between synchronous speed and no-load speed is the evidence of friction losses.

 

[dlgoff]

The other big friction source is the bearings. Even the very best bearings always have some friction.

This article, Wind 'em Up and Let 'em Go, from ecmweb.com give three things concerning bearing friction losses.

Over lubrication of bearings will increase friction losses and shorten bearing life.

Mixing incompatible greases will increase friction losses and impair lubrication.

Ensure that bearings have the same internal clearance as original bearings. Decreasing the clearances could increase the friction losses.

What effort did you make to answer these basic questions for yourself before asking others to invest their effort ?

Ditto. But for the other readers, I invested a little effort.

 

[Windadct]

Just spend a little and get better bearings!