zim Posted February 26, 2012 Share Posted February 26, 2012 Morning, I would like to know what the engineering people's opinion are of this please. If i were to get a needle roller bearing without inner race, such as : Would it be ok for me to machine a shaft to the required OD to run this bearing on ? What material would be adviseable to use ? Would it be better to be stainless compared to mild ? If so, will it be ok to weld a stainless collar to the outside of my mild steel shaft ? I'm assuming so if we got the right tig rods (I'm not the welder, my co-driver James is, but i'm away at the moment). Cheers Gordon Quote Link to comment Share on other sites More sharing options...
Steve Hiatt Posted February 26, 2012 Share Posted February 26, 2012 I have experience the other way round. On my racer I use nylon skiffy bushes on the wishbones. Every inner pin I've used has worn after a couple of races. I've used mild steel, ali and stainless pins. A couple of years ago someone suggested turning the pins down and pushing on needle bearing inner races. This has been very successful, they don't wear at all. So whilst I'm no engineer my conclusion would be that not using the inner race is likely to cause wear. Can you turn your shaft down a little more and push an inner race on? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted February 26, 2012 Share Posted February 26, 2012 RRCs have this setup inside the stub axle to support the CV joint. They rarely wear here either, but I'm guessing the CV joint is a fair bit harder than plain old mild steel.... Quote Link to comment Share on other sites More sharing options...
zoltan Posted February 26, 2012 Share Posted February 26, 2012 Is this baering carrying any load? The shaft would would be too soft, it needs to be hardened. Can you not use an inner race over your shaft or don't you have space? Quote Link to comment Share on other sites More sharing options...
ejparrott Posted February 26, 2012 Share Posted February 26, 2012 If at all possible I'd use the complete bearing assembly with an inner race. If its carrying substatial load you'd need to use an appropraite steel, have it nitrided, and then grind to size. If you're not carrying massive amounts of load, then I'd use an En24 steel, which is damn tough! Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted February 26, 2012 Share Posted February 26, 2012 As stated what ever you run the bearing on then it'd have to be case hardened at least. You'll also find that the bearing shown will shrink slightly when its pressed into its hole. Quote Link to comment Share on other sites More sharing options...
big len Posted February 26, 2012 Share Posted February 26, 2012 SKF is your best friend in these situations, they have an absolute wealth of knowledge on their site. There is a piece on these bearing on there, what tolerences, finishes hardness etc http://www.skf.com/portal/skf/home/products?maincatalogue=1〈=en&newlink=1_5_0 Generally I would go with an EN24 steel and harden it slightly more than the bearing - Im assuming you would rather the bearing wears rather than the shaft ? Lower content steels cannot be simply heat hardened so do make sure its en24 you buy and then simply google the temps required. One last thing, don't forget a very gentle chamfer on the shaft to fit the bearings say 30 degrees, needle bearings will be damaged without one. Quote Link to comment Share on other sites More sharing options...
ejparrott Posted February 26, 2012 Share Posted February 26, 2012 http://www.specialsteels.co.za/html/en24.html somewhere i've got in the back of my mind that EN24 is a flame hardening steel....can't seem to find a reference to it though... Quote Link to comment Share on other sites More sharing options...
big len Posted February 26, 2012 Share Posted February 26, 2012 http://www.specialst.../html/en24.html somewhere i've got in the back of my mind that EN24 is a flame hardening steel....can't seem to find a reference to it though... It is indeed, and will also work with furnaces, induction, and any heat source - bar a microwave of course Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted February 26, 2012 Share Posted February 26, 2012 3B will case harden fine it just lacks tensile strength. If your after strength as well then not much beats En36C... You just have to find it. Quote Link to comment Share on other sites More sharing options...
zim Posted February 27, 2012 Author Share Posted February 27, 2012 Thank you. The shaft is about 120mm OD, i don't really have that much space to run an inner race...but i'll have a look to see if possible. Cheers Gordon Quote Link to comment Share on other sites More sharing options...
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