----- Original Message -----
Sent: Monday, January 24, 2005 12:54
PM
Subject: [FlyRotary] Performance
coatings- bearing damage?
Greetings,
I just talked to Brad at
Performance Coatings, and he said they try to batch items together, to keep
from wasting material. For scheduling purposes, it's interesting to note
that they do piston tops, and rotors on Wednesdays. They
charge $45 for each rotor. The process includes blasting the rotor
faces, spraying on the coating, and curing it at 350 degrees. They have
a fixture that they use on rotors, which keeps anything from touching the
bearing.
Will the bearing be
damaged at 350 degrees? I'm thinking there's a
good chance it will.
Thanks,
Rusty (still
undecided)
Rusty, I suspect our
rotary bearings are better than the older babbitt bearings - but, I know
nothing about what the wear surface of todays automobile bearings are.
In any case, it looks if they were made of babbitt 350F would be a bit too
much. The question is would the bearing get to 350F before the rotor's
outter surfaces?
Ed A
-
Babbitt has good load carrying capacity between
800 PSI and 1500 PSI
-
Maximum operating temperature for Babbitt is 300º
F. In motors 180º F to 190º F is considered running hot. Some turbine
applications run as high as 225° F. Many technicians however, will set the
alarm at 185º F and trip at 205º F.
-
Melting temperature for common Babbitt varies
from 350º F to 475º
F
- Special bonding techniques are required to
metallurgically bond Babbitt to metal