Traction Motor Maintenance

[OCSCowboy]

Good day lads and ladies, 

 

I'm an ex Conductor/Carman in Canada, now working for an Oil and Lubricant producer. I know how to break locomotives, and repair railcars, but not enough about how Locomotives are serviced. 

Can anyone tell me what interval traction motors on GE/EMD motors are serviced? 

I have seen guys using bags (pods of fluid to fling into the TM, with synthetic product inside. I think this may be an older generation thing, but I wonder if the bag breaking down is affecting how well it works. 

 

We also provide Bearing grease for traction motors, and I would assume this is 'packed' at first application or rebuild, does it sound right? 

 

Thank you in advance, I appreciate you all and your expertise would be very helpful!

[BaltACD]

Welcome.

While I have no direct knowledge of shop operations.  It is the carriers intent that all servicing beyond fuel, sand, brake shoes and toilet cleaning be done on mandated Quartly Inspecttions.

[D.Carleton]

Unfortunately there is no clear cut answer. Railroad mechanical managers develop their inspection intervals based on the Federal requirements (49CFR229), OEM maintenance instructions and wear-and-tear caused by operations. The bags you described are lubrication for the traction motor pinion gear and axle bull gear. Newer traction motor combos use gear oil for this. Newer locomotives with microprocessor controls have periodic inspections every 184 days. Older locomotives' periodic inspections are every 92 days. These are typically where trucks will be inspected and lubrication check/added, again, following OEM instructions.

[Pneudyne]

OCSCowboy

I have seen guys using bags (pods of fluid to fling into the TM, with synthetic product inside. I think this may be an older generation thing, but I wonder if the bag breaking down is affecting how well it works.   

 

The use of polyethylene bags for traction motor gear lubricant goes back to the time when very high viscosity, and naturally tacky bituminous oils were used.  Packaging in manageable bags made the product much easier to handle, particularly for top-up purposes.  The polyethylene bags were quickly shredded by the gears, and had no observable deleterious effect on the lubricant performance.  The very high oil viscosity served both to minimize leakage through what were imperfect seals, as well as providing adequate load carrying capacity for the gears in the absence of any extreme pressure (EP) additive systems.

 

The polyethylene bagging practice was carried over to the next phase, which was the use of semi-fluid greases formulated with relatively high viscosity oils and EP additives.  The grease, which had high apparent viscosity when subject to low shearing forces, served as a sealant.  My recollection, not necessarily correct, is that GE was the prime mover of this change.

 

The move to EP gear oils, mineral and synthetic essentially derived from heavy duty automotive practice, came about with better gearcase sealing technologies, which allowed the viscosity and other characteristics to be determined mostly by the needs of the gears.

 

 

Cheers,

 

 

[bogie_engineer]

The EMD AC traction motor and gearing system was adapted from a Siemens design that uses the gear case oil lubricant to also lubricate the pinion end traction motor armature cylindrical bearing. The non-pinion end ball bearing is sealed and grease lubricated. There is a "scoop" above the pinion on the motor bearing end cover that directs some of the oil splashing from the gears into the pinion end bearing. This necessitated the design of a heavy, robust gearcase and seals to retain the oil, unlike the relatively flimsy DC traction motor gearcased that used the bagged "crater compound" that was not so difficult to seal. Those gearcases also had an overflow channel that would purge excess lubricant when it was heated up by the working of the gears if the gearcase was overfilled, as evidenced by the stripes of grease you see on the ties close to the inner sides of the rails.

Dave

[mvlandsw]

There was a time in the nineties when there were locomotive cow pies of sticky lubricant scattered about the tracks just waiting to gum up your shoes. They leaked out of the gearboxes wherever a locomotive sat still for any length ot time.

Polyethylene bags of lubricant were added to the center plate whenever a car was jacked up off of its trucks at the Union Railroad car shops.

[BaltACD]

mvlandsw

There was a time in the nineties when there were locomotive cow pies of sticky lubricant scattered about the tracks just waiting to gum up your shoes. They leaked out of the gearboxes wherever a locomotive sat still for any length ot time.

Polyethylene bags of lubricant were added to the center plate whenever a car was jacked up off of its trucks at the Union Railroad car shops.

Traction motor grease 'cow pies' were much in evidence in the 1960's 70's and 80's as well.