Thermal expansion of an interference fit

1. Jan 16, 2012

pardoeje

I have a bearing that is fixed into its housing by means of an interference fit (to test the effects of having a bearing that has become stuck due to build up of contaminants). I am using a bearing of ID 15.92mm ± 0.005 made of High lead Tin Bronze Alloy with a thermal coefficient of expansion equal to 18.5x10-6 1/°C within a housing with a hole of 15.88mm ± 0.005 made of Grey Cast Iron with a thermal coefficient of expansion equal to 11.7x10-6 1/°C. How do I calculate what the inside diameter of the housing will be when the part is running (delatT = 280°C). I have tried using the linear thermal expansion equation but due to the complex geometry of the housing I'm not really sure what OD to use for this method?

Any help would be greatly appreciated.

2. Jan 21, 2012

GT1

Usually with interface fits the change in the diameters is proportional to the module young of the materials. (so if you have 0.01 mm interface fit and both materials have the same module young then one diameter is now D1+0.005mm and the other diameter is D2-0.005mm).
You can also try NSK catalog - pages A82-A95.

Last edited: Jan 21, 2012