Sew Eurodrive Brake Motor

[bryan372002 0]

I have a sew brake motor running off a powerflex 70 on a control logix axis card (mo2ae) Brake is only unenergized (brake holding) when the machine is turned off or a safety gate/device is activated, otherwise the drive is enabled ,brake is energized and motor is going to or holding a position based off encoder. we have heard a noise that kinda sounds like a bad bearing, but while studting it today we noticed that while holding postion there is a intermitant humming noise and vibration almost as if it were single phasing, well if it were single phasing the drive would fault. any my thought is and tell me if I am crazy...lol could it maybe be the brake or brake coil chattering or likewise. the motor is also running quite hot. maybe brake coil is generating excessive heat ? We have had no drive or axis faults of no kind. any ideas? Thanks in advance

[OkiePC 14]

I have a similar ongoing issue with a sew eurodrive servogearmotor with integral brake...I don't have any good answers for you (yet), but we have had four motor failures in two years on the same machine, at least two of them were most likely brake failures. http://www.plctalk.net/qanda/showthread.php?t=40684 The OEM of the machine has been pretty useless for tech support, after promising to give me testing procedures and voltage readings for our brake control module, he sent me an email a week later saying "Ralf thinks its the brake module" and attached a screenshot of the motor/drive wiring diagram (which we already have). I plan to contact SEW tech support as soon as I get the chance and get more information from them directly. IMHOO (Humble Okie Opinion) the brake is being overheated because we leave it sitting there energized all night long and let the servo drive hold the motor still too (adding even more heat to that little block of precious metals). Our machine is running fine at the moment, and I have asked the 2nd shift to press the e-stop after production ends to offer that coil some electrical relief, but I doubt that solution will be followed correctly long term and isn't a satisfactory solution for me. The OEM of our machine is quite protective of their code and very hesitant to follow my suggestion that they change it to time out and relax after going idle for x number of seconds. They also have informed us that any unauthorized changes will void our warranty and end free tech support. They did that in conjunction with another change we requested to support some upcoming product changes. We got their approval for my changes then, so maybe they will let me fix their stinking brake problem too and approve it as well. Right now, its on the back burner...Mine is being driven by a SEW Movidrive Compact in indexing mode with commands coming from a SLC via a Profibus card, so when I get around to changing the code I have some serious learning to do, since I have no experience with Profibus or the Movidrive. At least they gave me the (half German) SLC file so I now have comments and symbols to help me decipher it... Let me know your full motor part number and I will be sure to post back if I learn something useful to us both. Paul Edited 7 Aug 2008 by OkiePC

[bryan372002 0]

Thanks Paul, I'l get that motor data tommorrow and share it with You. and likewise I'll let You know if I learn anything.