Broken Pulley Shaft Fracture Surface
Broken Pulley Shaft Fracture Surface
(OP)
Hi everyone,
What you think about this fracture surface.
On a newly installed conveyor this pulley shaft is broken after 1,5 month of operation time. Slow speed application app. 120 rpm.
I don't have much experience on failure analysis of machine shafts. Son can anyone please help me out on this issue.
What you think about this fracture surface.
On a newly installed conveyor this pulley shaft is broken after 1,5 month of operation time. Slow speed application app. 120 rpm.
I don't have much experience on failure analysis of machine shafts. Son can anyone please help me out on this issue.





RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
I know these are not easy questions to answer without analysis. I was looking just for ideas.
This is the 1st time this shaft failed, because it is a pretty new conveyor like i mentioned. Unfortunately I cant efford to spend money for this failure now.
Thanks,
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
Your comment, suggests, that you are not willing to spend for testing and verification,but you shall have to source a replacement shaft, to keep your machine running!!.
Perform some of the basic tests to understand failure.
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
I guess you guys tangled up with this sentence. Sorry about that, maybe i misexplained my self.I don't afraid to spend money for analysis, just i think i don't need to for this case.
We got more then 100 pullies in this plant with similar size, similar material, similar applications. I don't think it is related with shaft material. This recent upgrade project conveyor pulley shaft is failed. There may be 2 reasons for that.
Either the take up unit attached to this pulley was tightened too much or tightened unevenly on both sides or because of the slightly bended installation of the pulley housing base frame every thing is flexing in and out at every turn of pulley shaft.I realized that couple of days ago top of the bearing housings flexing (moving) in and out every turn.So my original question was is it a sudden failure(brittle kind of failure) or happened slowly with time (because of over tightening)
I'm not sure about the condition of the new pulley now. I'm a vib. guy so my way to check this pulley is to follow the phase of 1X vibration with time. Didn't seem getting worse last 3 days.
I'm working both on frame and tightening procedure now anyway.
Thanks,
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
It is in your interest to have a specialist in metallurgical failure analysis work with you to identify the root cause, even if that person ends up confirming your diagnosis. You are a vib guy, and you need someone with appropriate experience to help you.
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
RE: Broken Pulley Shaft Fracture Surface
pls. have a look at my last post in the parallel thread,
http://www.eng-tips.com/viewthread.cfm?qid=407934
KR
R.
RSVP
RE: Broken Pulley Shaft Fracture Surface
Maui