heat installation of bearing

[WPM3022]

Hello

looking to heat a fabricated housing of a bearing to aid its installation.

can someone please guide as to the temperature I can take it to without any ramifications (i.e. it cools down and there are no effects)?

Steel is 350MPa yeild strength

Thank you

 

[CWB1]

can someone please guide as to the temperature I can take it to without any ramifications (i.e. it cools down and there are no effects)?

Whatever your current temperature is. Heat the part one degree and it will change size and shape to some extent. Thin sections generally distort first and worst, but distortion really depends on the part's geometry. Another important consideration is how the heat is applied. I've seen plenty of bearing housings warped by ignorance and a torch, locally heating a housing that should've been heated slowly/evenly throughout in an oven.

 

[SandCounter]

In addition to heating and cooling evenly and slowly, you will want to consult an iron-carbon diagram, CCT, or TTT curves for your alloy to ensure you are not changing the phase or allotrope. I usually try to stay under 500°F for what I deal with, but really, you want to use the lowest temperature you can and still accomplish the fit. Anything you have to heat up to assemble, you have to heat up to disassemble as well and if your room temperature fit is too tight, you will never be able to heat up the outer quick enough to remove it before the heat transfers to the inner and it expands as well.

I used to count sand. Now I don't count at all.

 

[Tmoose]

How much interference does the bearing have in the housing ?
What is the bearing OD?

 

[dhengr]

WPM3022:
The bearing manuf’r. should give you the interference fit range that they want used with their bearing, either with the bearing packaging, in their literature, or by phone from the Eng’rg. Dept. Measure the bearing for its o.d. Then, btwn. the boring machining and that fit, you should be able to do a reasonable calc. which will get you the approx. temp. you need to heat the piece to. And, of course, the heating should be done unfirmly, evenly all around, both sides and outward with sufficient added radius and gradually. You are probably only talking about .001 or .002” on the bearing o.d.

 

[chicopee]

Conversely, about cooling the bearing with dry ice before installing it.

 

[DAVIDSTECKER]

There is a very good equation in the Machinery Handbook for shrink fits by heating if I recall.