lack of any seal at shaft on TENV motor
lack of any seal at shaft on TENV motor
(OP)
We have a small (5hp?) TENV crane motor in outdoor application, approx 2 years old. We recently heard lots of vibration. Investigated and found that the drive end had apparent moisture intrusion. Shaft and external bearing surfaces inside motor showed early signs of rust. Bearings are double-shielded (require no lubrication).
Inspection shows that shaft penetrates the end bell and there is no lip seal or slinger ring or anything (other than close clearance between housing and shaft) to prevent moisture entry. There was however grease in the end bell bearing cavity, which is strange since it's a double-shielded bearing. Called manufacturer who told us that the grease is intended to stop the entrance of moisture around the shaft, and we should replenish it to solve the problem.
That sounds pretty hokey to me. What do you guys think?
Inspection shows that shaft penetrates the end bell and there is no lip seal or slinger ring or anything (other than close clearance between housing and shaft) to prevent moisture entry. There was however grease in the end bell bearing cavity, which is strange since it's a double-shielded bearing. Called manufacturer who told us that the grease is intended to stop the entrance of moisture around the shaft, and we should replenish it to solve the problem.
That sounds pretty hokey to me. What do you guys think?





RE: lack of any seal at shaft on TENV motor
RE: lack of any seal at shaft on TENV motor
however for outdoor service ip55 vee rings should be fitted to the outboard side of the shaft and run up against the end cover(bs 4999:part 20 iec publication 34-5).
the only time grease should be used is when a double cavity is present in the end cap and grease relief is fitted. a slinger should also be fitted.
should you require drawings pls advise email address
kind regds.
RE: lack of any seal at shaft on TENV motor
I assumed that this defines the degree of protection and I would have assumed that is good enough for outdoor service. (but I might be wrong... is there something else on the nameplate that tells the degree of protection.
NEMA MG-1-1998Rev1 SECTION 1.26.1 seems to equate TENV with "IC410", but I can't decode what those letters stand for.
RE: lack of any seal at shaft on TENV motor
most i.e.c machines state the ip rating on the name plate.
if you are going to change the bearings, we reccomend you fit a vee ring or some type of slinger to prevent this re occuring.
kind regds.
RE: lack of any seal at shaft on TENV motor
Although the logic escapes me. The only reason I can see for building a TENV motor would be for ingress protection. (it's a 25hp motor by the way, not 5hp). Why would a manufacturer (not teco) offer a TENV that has no attempt to seal the shaft?
RE: lack of any seal at shaft on TENV motor
in you case we think an over sight was made on initial application engineering .
kind regds.
RE: lack of any seal at shaft on TENV motor
But still... doesn't a TENV cost more than a comparable open motor? Why would anyone build or specify on except to exclude moisture/contaminants or possibly for hazardous environment?
By the way: what does IC stand for?
RE: lack of any seal at shaft on TENV motor
If the IC and IP ratings are truly separate, does that also mean that an IC rating corresponding to Open, Weather Protected Type II is not necessarily suitable for outdoor operation (may not have any shaft seal)?
Comment: The terminology ("weather protected","totally enclosed") sounds a little misleading since it sounds like those types should be suitable for outdoor use. (I realize the proper answer would be to specify an IP rating IPX3, 4, 5,6,7,8).
RE: lack of any seal at shaft on TENV motor
we would suggest in future if you spec new or repaired machines ip55 you can use them for inside or outdoor service.
kind regds.