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I am not a mechanical engineer :) I feel much better with electronics, but I have a project in your domain now.

So, I have an aluminum housing, a steel bearing and an aluminum axis. I need to put them together. In my basement. They are designed to have the same diameter-30mm for the housing and 17mm for the bearing.

What preparations do I need? What equipment? What is the optimal method?

This is the bearing I am going to use :

https://www.skf.com/ca/en/products/rolling-bearings/roller-bearings/needle-roller-bearings/needle-roller-bearings-with-machined-rings/productid-NA%204903%20RS

Gregory Kornblum
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1 Answers1

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Installing bearings is much easier than removing them.

Preparation

The main thing is that you keep Bearings and surfaces Clean. Make sure that you don't get the bearing into contact with contaminant, and clean the surfaces before installation.

The another important thing - it might seem obvious - its to double check the dimensions of the bearing and the hole (fits and clearances). Usually, the bearing manufacturer has a pretty detailed manual with shaft tolerances depending on many factors (e.g. shaft diameter, type and magnitude of load etc).

Finally, the most important thing is handle bearings with care. If they fall on the floor, or have even relatively minor impacts, then the ball (or other rolling elements) can develop dents which will a) reduce the life of the bearing, b) make the bearing underperform.

installation methods

There are a few installation methods. Sometimes all its need is the hand pressure (some even go as far as saying that, if you can't fit a bearing with the pressure of your hand you are doing something wrong).

The next step is mallet with a Bearing Fitting Tool

enter image description here figure 1: SKF Bearing Fitting Tool Kit Hammer, TMFT 36-H (source indiamart)

Then there is the hot mounting method (this is usually for medium sized bearings. Essentially what happens is that you heat the bearing in order to increase its size and then you slide in the shaft. That has the effect that the bearing is then essentially pressfitted on the shaft

enter image description here figure: SKF bearing heaters (source Wychbearings)

The final option is probably hydraulic mounting (although this is for much larger bearings).

NMech
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  • Thank you! I am in a small trouble here, I don't understand the clearance requirements. It says P6, P5, whatever it means. Mind having a look? – Gregory Kornblum Sep 06 '21 at 01:24
  • https://www.skf.com/ca/en/products/rolling-bearings/roller-bearings/needle-roller-bearings/needle-roller-bearings-with-machined-rings/productid-NA%204903%20RS – Gregory Kornblum Sep 06 '21 at 01:24
  • P6 and P5 (or less) its a class categorization specific to SKF - at least to my knowledge. Basically Normal has wider tolerances, P6 smaller, P5 even smaller and SKF boasts that it can do smaller than P5 which collectively calls superbearings. SKF has a mount/dismount link which usually describes the procedure. However keep in mind, that the tolerances are significantly affected by loading conditions. – NMech Sep 06 '21 at 01:37
  • Can I use some generic fitting tool, or should it be by the same vendor that I take bearings from? – Gregory Kornblum Sep 06 '21 at 01:59
  • So the load should be roughly 200kg, axially and radially. Not sure about torsion. – Gregory Kornblum Sep 06 '21 at 03:02
  • You can use fitting tools on bearings from different companies. Regardig the load, I think there is some sort of confusion. I don't think those bearings can transfer axial loads very well, so please if this is the recommended bearing for your application. – NMech Sep 06 '21 at 05:02
  • Thank you, I will check again!! – Gregory Kornblum Sep 06 '21 at 05:08
  • @NMech Not all bearings can be fitted by hand - some are an interference fit and the shaft, or bearing, needs to be either heated or cooled or both to be able to fit them. I pressed, by hand, new valve guides into a cylinder head by having the valve guides in the freezer for 2 hours and the cylinder head in the oven for 2 hours. Worked a treat. At work we just used a press... – Solar Mike Sep 06 '21 at 05:27
  • @SolarMike can you help me with the tolerance definition? it is all nice in a drawing, but i have no idea what do define for the manudacturer. – Gregory Kornblum Sep 06 '21 at 17:53