leaking seals
leaking seals
(OP)
I have a 1/4" seal seated onto a TGP 1/4"shaft. The seal is a double lip with a spring and is pressfit into a housing. we never had any problems with leaking.
But this one assembly that has been assembled is leaking. One or two them, may be a bad piece. But all fifteen out of fifteen are leaking where the mate occurs from the shaft. The pressfit holes are measured and all are within spec.
The max temp of the seal is 180°C and 8000RPM. The temperatures i measured are 100-120°F running at 1500rpm.
now whats making it leak....hmm...well the whole assembly as a gear - bearing - then seal.
But this one assembly that has been assembled is leaking. One or two them, may be a bad piece. But all fifteen out of fifteen are leaking where the mate occurs from the shaft. The pressfit holes are measured and all are within spec.
The max temp of the seal is 180°C and 8000RPM. The temperatures i measured are 100-120°F running at 1500rpm.
now whats making it leak....hmm...well the whole assembly as a gear - bearing - then seal.





RE: leaking seals
What type of seal is it? U-cup, or Lip-seal? How are the lips configured?
If they are U-cup or lip seal then the leakage might be due to bad installation. During installation, the seal might be damaged by a sharp edge bad or installation technique. Also, the mating surface must be better than 16 RMS.
What about pressure?
if you have a sketch or Autocad drawing of the setup I might be able to help you more. Send it to bogiedreamer@gmail.com
RE: leaking seals
If the initial seals have been operating for a longer time on the same position on the shaft the shaft position might have gotten erroded.
In that case reface the shaft surface or position the seals in a slightly different unaffexted area of the shaft.
Best regards.
scalleke
RE: leaking seals
RE: leaking seals
RE: leaking seals
1. Could possibly have some shafts that are not plunge ground therefore creating a leak path similar to threads on a screw.
2. Do shafts have a small burr on the lead in chamfer that could be cutting the seal as you slide the seal onto the shaft? You should be using a bullet to assemble the seal if at all possible.
3. Can you see wear on one side of the seal (possibly misalignment problem) or are they failing instantly?
Good Luck,
bdlong@johncrane.com
RE: leaking seals