Bearing Internal clearance and misalignment
Bearing Internal clearance and misalignment
(OP)
I am evaluating a gearbox design received from a manufacturer and I notice that the mislaignment is about 8 minutes and the bearings used are deep groove ball bearings with C3 clearance. Manufacturer recommends max 10 minutes of mislaignment. The design is within that but it is usually advisable to work within lower misalignment angles.
Is C3 sufficient for taking up that value of mislaignmemt? As per manufacturer's catalogue the increased clearance bearings are used only for compensating higher temerature differential between inner and outer race and for compensating the expansion of inner race after shrink fit. It does not mention anything about compensating mislaignment by increasing clearance.
I would like to know what is the purpose of increased clearance bearings and will it eat up that kind of misalignment or is it inteneded to eat up misalignment at all?
Is C3 sufficient for taking up that value of mislaignmemt? As per manufacturer's catalogue the increased clearance bearings are used only for compensating higher temerature differential between inner and outer race and for compensating the expansion of inner race after shrink fit. It does not mention anything about compensating mislaignment by increasing clearance.
I would like to know what is the purpose of increased clearance bearings and will it eat up that kind of misalignment or is it inteneded to eat up misalignment at all?





RE: Bearing Internal clearance and misalignment
Check this link;
http://w
RE: Bearing Internal clearance and misalignment
lower turning torques and allow more
misalignment. The trouble with angular
measurements without knowing the size
range is that it is difficult to translate
into a dimensional range. I assume you
will have to pay a premium for reduced
clearances.
RE: Bearing Internal clearance and misalignment
RE: Bearing Internal clearance and misalignment
Is there any evidence of that happening. I tried to search SKF website but could not find any info to corroborate your view.
RE: Bearing Internal clearance and misalignment
One note, all of the industrial machinery I work with uses C3 clearance, so I tend to think of it as normal clearance, in spite of the AFBMA terminology.
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RE: Bearing Internal clearance and misalignment
RE: Bearing Internal clearance and misalignment
RE: Bearing Internal clearance and misalignment
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Eng-tips forums: The best place on the web for engineering discussions.
RE: Bearing Internal clearance and misalignment
Do you have actual data or calculations which we can have a look at? The application, size of the gear box, gear design, gear quality, material,heat treatment, lubrication, horse power etc. are some of the factors which will also affect the life. I assume that the other factors were same while comparing the mislaignment.
RE: Bearing Internal clearance and misalignment
"Single row deep groove ball bearings have only limited ability to accommodate errors of alignment. The permissible angular misalignment between inner and outer rings, which will not produce inadmissibly high additional stresses in the bearing, depends on the radial internal clearance of the bearing in operation, bearing size, the internal design and the forces and moments acting on the bearing. Because of the complex relationship between these factors, no generally applicable specific values can be given. Depending on the various influences of the factors, the permissible angular misalignment lies between 2 and 10 minutes of arc. Any greater misalignment will result in a considerable increase in bearing noise in operation."
Still interested to hear from jmoritz
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RE: Bearing Internal clearance and misalignment
just a thought.
Lester Milton
Telford, Shropshire, UK
RE: Bearing Internal clearance and misalignment