Brake Pad Mechanism

[Clayts]

Hi All.

 

Interesting problem here.

 

Sparky serviced a brake mechanism that was chattering and decided to file and polish face of laminations (surrounding coil) to make for good contact (shading rings in place ok)... It worked, only In doing so there are major eddies on the pole faces leaving a huge residual magnetism and causing the laminations to stick together after coil is de-energized.. I'm assuming (even though there is a very strong tension spring pulling them apart again) . It’s going to take hours even a day to separate and re-varnish every lamination and is therefore not really worth doing logistically. Is there another way anybody can think of to dissipate residual from pole faces/laminations after supply is broken?.

 

Our only other idea is to skim faces to hope for a difference!

 

[marke]

I assume that this is a DC coil assembly??

[Clayts]

I assume that this is a DC coil assembly??

 

No it's 400V AC across two lines, I believe thats the purpose of the shading rings to reduce chatter (stop fields from disappearing between cycles) kind of like shading ring of shaded pole motors to create a lag.

 

 

[Clayts]

UPDATE

 

Shaved off pole surfaces and got perfectly square..didn't do it

reduced tension spring which helped a little, then figured not strong enough field, so upped the voltage on variac to 480ish with no difference to chatter (under 400 was a huge increase in chatter). otherwise could have increased turns

 

Then continued to hold magnetism until seperated manually when nothing but laminations touching - bizarre

 

Swore at it

 

Bought a solinoid ..most powerful I could find was a TT10 (from memory). should be strong enough, but will check current under load and know soon enough!.