motor shaft repair
motor shaft repair
(OP)
Hello everyone:
I have a 60HP Delco-Remy AC motor that is about 30 years old. The shaft broke on one end due to the hydraulic pump seizing (which needs to be rebuilt). I have yet to take the motor end caps off, but I was wondering if the shaft slides inside an "armature sleeve" or does the whole armature need to be taken out? Also, can the shaft be repaired or does it need to be replaced? Thanks.
I have a 60HP Delco-Remy AC motor that is about 30 years old. The shaft broke on one end due to the hydraulic pump seizing (which needs to be rebuilt). I have yet to take the motor end caps off, but I was wondering if the shaft slides inside an "armature sleeve" or does the whole armature need to be taken out? Also, can the shaft be repaired or does it need to be replaced? Thanks.





RE: motor shaft repair
Don't disassemble it, just take the intact motor to your local electric motor rebuilder. He can probably repair it better/ faster/ cheaper than you can.
Ask about making the repair frangible, so the pump drive spline(?) can be replaced without motor disassembly the next time the pump seizes. Or, not; you'll be gone by then.
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA
RE: motor shaft repair
RE: motor shaft repair
RE: motor shaft repair
RE: motor shaft repair
Shaft repair is quite common and can be done by most motor repair shops. The costs will depend on where the shaft broke (in front of bearing or behind bearing). Some shops can stub a new shaft piece onto old shaft, or depending on damage, a new shaft will have to be made.
RE: motor shaft repair
If this motor and hydraulic pump were built for each other before the days of C-faces you might have to replace both the motor and the pump. If it is too hard to attach a new motor to the existing pump that is your best option. Plumbing is very easy to reengineer, custome motor frames are not.
RE: motor shaft repair
RE: motor shaft repair
On the slim chance that anything is fitted internally, it is almost always located at behind the NDE endbell, so it would be apparent as soon as you pop the cover.
----------------------------------
If we learn from our mistakes,
I'm getting a great education!
RE: motor shaft repair
have fun.
RE: motor shaft repair
is some of the old Delco ODP motors have internal cooling fan on the DE side of the motor. The fan is larger than the rotor bore, so pulling the rotor from the non-drive end side of the motor, the fan will hit the winding.
If you can see inside the motor (its ODP) and can determine if motor has internal cooling fan. The TEFC motors do not have internal fans.
RE: motor shaft repair
Assuming this is a run-of-the mill horizontal T-frame squirrel cage induction motor available off the shelf we would buy a new one for one or two thousand dollars and sell the old one for scrap.
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RE: motor shaft repair
If you go the rotor repair option make sure your shop knows what they're doing.
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
RE: motor shaft repair
RE: motor shaft repair
By the way, 60HP in an injection machine? That must be a dooser... 200 Ton?
RE: motor shaft repair
RE: motor shaft repair
RE: motor shaft repair
RE: motor shaft repair
I quote for and deal with repairs of this nature on a regular basis. Assuming its an AC motor a shaft replacement is the best option. Stub repairs and sleeves simply will not be strong enough for 60 hp especially if its a 2 pole machine. Shaft replacement is a routine procedure for a competent and I stress competent repair company but its a question of cost against options and benefits, and the repair will probably cost more than a modern replacement motor and mounting mods. Get the pump inspected first as it may be imposible to repair, if its snapped a 60hp shaft its almost certain to have caused some serious damge to the pump internals when it seized up. The whole motor would have to be removed from the pump and dismantled to allow the bearing housings/journals and other parts to be checked otherwise you are unlikely to get a guarantee. Also the pump driveshaft will need to be checked for damage. A detailed drawing would be made of all shaft dimensions then the broken shaft reminants would be bored out of the rotor pack. This method ensures no damage to the laminations. A new shaft would be roughed out and keywayed to fit the rotor pack. Insist on EN24T steel. Best to use controlled heat expansion on the pack when fitting the shaft and keep interference and pressure fitting to a minimum, again to avoid the risk of damage to the rotor pack. The D/E and N/D/E shaft extensions can then be finished turned, trued to the rotor and the whole assembly then balanced. Then its a couple of new bearings a winding overhaul and a final test.......Then the following month a big bill from the repair Co.!! We did one recently for a 175hp motor that was about 40 years old, it drove an industrial centrifuge and it was impossible to replace the motor or modify the machine, cost was about £3.5k. If I was in your position I would seriously consider approaching several reputable Hydraulic Engineering firms and getting quotes to replace the pump and motor with modern and more efficient replacements.
RE: motor shaft repair
If this motor is a T frame, which it may not be as the AC Delco motors were often specials, throw it away and buy an energy efficient motor, the power savings will pay for the new motor in approx 3 years. Read the name plate before you buy new, make sure the motor you buy will do the job.
Many Delco motors have copper bar rotors and most standard motors in the HP range are now Aluminum di-cast. Check the code letter on the name plate. Codes E,F and G are normal.
These codes affect the starting current or Locked rotor current.
RE: motor shaft repair
Replace the motor!
RE: motor shaft repair
P.S.: Can jpg's be posted in the forums? I can take a pic of the broken shaft.
RE: motor shaft repair
If you have the ability to place the file on the internet somewhere then you can link to it or include it in your post using the [img] ubb tags.
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
RE: motor shaft repair
The way I see it is that you have two problems here, the snapped shaft is one of them but this is a secondary issue and relatively easy to overcome by replacement. The second and more serious problem is WHY it snapped in the first place. My thoughts would be to find out how it happened as shafts do not snap without good reason. Then base your next move on the findings. You might pay a large amount of money for a repair and then a week later the same thing happens and it snaps again as a result of an underlying and overlooked fault. If as you say it has been repaired before that suggests to me a sub-standard repair method was employed that if repeated will be unreliable. Alternatively a ongoing problem may exist with the driven pump that is causing the shaft to fail, this may be imposible or not cost effective to repair given the age of it. If you were in the UK I could offer more advice but unfortunately thats not the case so I suggest you contact a local company thats both reputable and a member of EASA and speak to them about it. A final piece of advice is to get a guarantee, if they wont agree to it walk away and find someone who will. This is going to cost you money to put right but make sure its the right, amount spent on the right repair, and for the right reasons.
P.S.
If you do invite comments from a repair company I would be interested to hear what they have to say.
Thanks
RE: motor shaft repair
RE: motor shaft repair
That sounds like a misalignment problem.
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA
RE: motor shaft repair