Hi guys i wanted to make this thread to get some info on bore sizes for different machinery, as we all know it, its not easy getting sizes from manufacturers, and the bushes and pins are not always on the job to go off, if anyone has a website that can access this info for any machinery, cat, komatsu, jcb, hitachi, case, liebherr, bucyrus and on and on, trucks, dozers, scrapers, graders, diggers, anything that has hole with some sizes and tolerances would be helpful thanks.
One helpful site is the JDParts website. You can search part #'s and many pins/bushings list the ID, OD, Length, Material, etc. You can also search by spec so if you need a 3.25"id x 4"od you can see what's available. Oh, and they do list as metric also for you upsidedown folks.
yeah i just looked into jdparts, you will have to sign up to the website and to access that particular part you have to add it to the cart and the open in it in the shopping cart will take you to dimensions, thank you.
CQ...I don't have the tolerances, but you might be interested in the last post of my thread on pin-on bucket mounting specs for excavators at Maybe it will help a little...
There's people on this forum with much more experience with this than me, but personally when I'm machining a bore I prefer not to trust any chart with theoretical bushing sizes. I always prefer the bush on hand so I can check it with the mic to get the correct crush.
if you are "going off the bush size" do you use use the thou per every inch rule? or do you measure the od of the bush, the id of the bush and the pin diameter to work it out?
The 0.001" per inch dia seems to work out OK for me. A couple of years ago we machined a bore to Cat's spec without having the bush on hand. The bore was approx 6". When we eventually got the bush and measured it we found we had 0.011 crush. The bush went in - just. We left it in the liquid nitro for about 10 minutes; it was way cold. No more bubbles cold. Even then it took all the 50 ton hollow ram could give to get it home.
0.001"/inch seems to work well on Cat bushes, Hitachi tend to fit even tighter than that. Some are 0.0015"/inch, some are even .002"/inch. Hitachi bushes seem to need freezing in liquid nitrogen THEN the use of a 100T cylinder to get them in to the hole ..... As a rule I always leave whatever I'm freezing in the liquid nitrogen until the liquid stops boiling. At that point it is the same temperature as the liquid (-200C) and it's not going to shrink any more however much longer you leave it. Some big bushes I'll put them in the bearing freezer (-50C) first then drop them in the nitrogen and leave them in for 30 minutes or so, or until the liquid stops boiling.
Lol. I always find that race against the clock to get them in before they expand one of the more stressful moments of the working day. Especially as we're contracting and if the damn thing gets stuck halfway, it's our dollar.
What's referred to in the trade as a "sphincter tightener" .........
Yair . . . After being burnt a couple of times I got very scientific and instructed our machinists to work to maximum allowable plus a "smidgeon". You are not doing yourself any favours in working to minimum clearances on press fits, marine bearings and so forth. Cheers.
Cutting bores for bearings is easy enough when you have one to measure. The old thou per inch rule can get you out of trouble on Cat gear but put you in trouble on a lot of other stuff. A thou per inch on a Liebherr bearing and you won't get a pin through it. The manufacturer almost always builds the crush into the bearing A typicat Cat bearing will measure 4.004. Cut the bore 4 inch. Liebherr beariing. 210.08 mm. Cut the bore 210.00.etc
nominal specs i hear what you saying about been tight, but like nige said the hitachi specs are even tighter, we always used liquid nitrogen to shrink the bush and heated the bore with a log torch to open the hole bigger for even more clearance, its what we did and it worked fine for us..... thats something i look at too rayF is that most bores are a nominal size and the bore is the weird size with crush,
All most all bores are çut nominal size. Cat bearings in Imperial sizes are often toleranced minus. Eg. A 4.250 bearing in a 631 hitch will measure 4.254. The Cat size for the bore is 4.248 plus,minus .002. Most metric bores are toleranceď plus. There will typically be a H8 tolerance. The tolerance varies depending on the diameter. I think H8 on 210 mm is 0.08 plus. Most tooling and booklets like Zuess have the data. A comment on fitting bearings. When using liquid nitrogen it should never be necessary to press. Even on Hitachi where 0.5mm crush is common. Steel bearings shrink .002 per inch of dia. in nitrogen. If the bore is heated to 250c the bearing will go in easy enough. The trick to heating is to heat the whole area evenly. No good having the inside of the bore hotter than the surrounding area.The whole area must be hot for Hitachi type sizing. Bores must be spotless and checked for the tiniest burr. Bearing is left in nitrogen till its not boiling. Without rushing but not fooling around present the bearing to the bore and line it up and turn the bearing as you push it in. This turning will tend to self align it. Bronze bearings are easier. They reduce 4 thou per inch in nitrogen. A 350mm O&K bearing will have around 4 thou crush. A few times I have put the bearing in and then pulled it out because its so loose I was sure I'd cut the bore a mil to big. They can take 20 minutes to grab.
Good, accurate, technical stuff! I love it! In the mid 1970's, we were replacing swingshaft bushes on the Marion 8900 dragline in Moura, Central Queensland. We cooled the bushes in a tank filled with Nitropil and water. No idea of the temp but cold enough for the bushes to frost as soon as they were lifted out of the tank. Each of the shafts (five in total I think) had three bushes. On one, the middle bearing was out of line enough that the shaft would not go through, so orders were to "hand finish" it with 12 inch angle grinders !
Make the job easier with Hitachi bushigs. I think they are only on the 1100 and up sized machines, they have that black coating on them. Puta flap wheel on your die grinder and polish the bushing clean, then measure it to get the correct size.
Mate, the bearing already is the correct size.