DC Motor Sound

[507016]

What Actaully Causes Sound in DC motors. E.g. class 507, 319 and 313, and what causes them to get louder over time, is it the camshaft? The gears? Does anyone actaully know?

 

[Bletchleyite]

What Actaully Causes Sound in DC motors. E.g. class 507, 319 and 313, and what causes them to get louder over time, is it the camshaft? The gears? Does anyone actaully know?

In my understanding it is caused by straight-cut gears in the transmission (similarly to how many cars used to make a similar noise in reverse). This is backed up by it still being present on the reworked 230s despite these having had AC motors fitted.

 

[contrex]

Combination of gear whine and the actual rotating part of the motor I think. I asked a similar question in 2016

Traction motor sounds

As a small kid in the 1950s I used to hear older and newer EMU stock pass the end of our back garden, and on rail trips. I noticed that most older stock's motors sounded different from the 'newer' stock - I mean that (say) 1920s type SUBs, and the later BILs, LAVs etc had a kind of rich...

www.railforums.co.uk

 

[boiledbeans2]

In my understanding it is caused by straight-cut gears in the transmission (similarly to how many cars used to make a similar noise in reverse). This is backed up by it still being present on the reworked 230s despite these having had AC motors fitted.

They can be heard on the AC-motored SWR 455s as well, and some of them are loud - e.g. 5715.

 

[janahan]

Same with the 458s. Their inverters and electronics seem far quieter on the electrical side of things compared to Electrostars, Desiros and most other modern AC gear, that you are able to hear the motor sounds similar to a DC

 

[Nym]

High Ratio constant mesh straight cut gears from nose hung motors. In combination with a bit of brush noise and just generally heavy bits of kit.

The same noise for example isn't available on 1992TS which doesn't have a nose hung motor, not too sure on the number of stages to the gearbox but I believe it's a two stage one since build.