GTA
General Discussion To Gateway To Airguns => The Shop => : kiwi March 05, 2009, 10:55:50 AM
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Thrust bearrings!
I was reading a post thread on another forum I pop into
now and then "can't post there not a member"
A lot of yabber about needle berrings between the top hat & piston
Then it dawned on me Why use a berring that was never designed
for the job when there are berring designed to handle the load and impact.
Now I want to make it clear I'm NOT talking about those
Timkin needle bearring.
I am thinking of is a bearring made for high load siturations.
The bearring is a - 72XX or 73XX angular contact ball race.
When I'm designing machines for work I use them on almost
all dyinamic shafts that have a high thrust load.
The two only probs I can see with them is there thickness
& weight. The 4 that would prob be with in the size range
required for a air gun would be ----
7201 / 7202 or 7301 / 7302 " maybe 7203 / 7303 "
7 = berring type "angular contact"
2 or 3 = berring OD "most berring come in 2 sizes"
01 = berring ID - 5mm
02 = berring ID - 10mm
03 = " " - 15mm
I do realise there will be a few not knowing realy what the berring looks like
All just a thought but maybe worth someone
playing around with.
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some thing like this
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wow...i wish i knew anything about what you just said, haha!
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OH NO, not the thrust bearings again. I thought that we went over this subjectenough already. Thrust bearings are just as the name states. "Thrust". They were not designed for impact. And if this post goes on about this subject it will be putting itin the non productive forum. Ok CAP!...
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Just some very short imput. Thrust bearings of any kind are designed for thrust and are always designed for preload applications. None are designed for high impact, especially the impact developed within a springer. Play with it if ya like but be prepared for possibly very destructive results and purchasing a new gun. I have seen several with the end results.
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...lmao, i'm still so in the dark about this...i need to learn more about these guns!
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assemble the bearing and then hit it with a hammer for like 1000 strokes, no whimping out here hit that sucker hard, if it stands up to that then it might, just might work...
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Not even close
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Guess I need to post a pic of a 72XX / 73XX berring.
Good reply Mike.
Engineering wise....I never exsept that something can't be done
just a way has not be found.
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How about using some sintered phospher bronze bearings, They don't use balls or needles, they are like a flat washer which have been impregnated with a lube!
http://www.smallparts.com/s?searchKeywords=bronze
Might be worth a try! What do you guys think?
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Would bronze be hard enough....even steel washers can get bent with use....I use stainless steel and they get wear marks after a few thousand shots....
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Mike is right. A polished stainless steel thrust washer is more than suffice and will actually out perform a bearing.
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Referring to simply using one or more mollied washers at the spring ends to reduce the felt spring torque...I'm thinking maybe we should notcall it a "thrust" bearing. Maybe we should call it a "torque bearing". Or ATB for Anti-Torque Bearing.
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Got all my bearring books out....the smallest
they make 7 serises bearring is 7203
Thats in the Fag / SKF / NTN books.
Waisted post unless some other manifacturer
makes them in XX01 or XX02 size
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I tried the bronze impregnated washers. They broke apart and fell out the cocking slot. Have better performance with a plain lubed washer or a "penny" which fits perfect. I really prefer the Penny.. Frank
The copper penny, not the zinc..
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i hate to sound conceded but u "engineers" really do just read to much "books" and not just actually try some thing in the real world.!! a high silica bronze or aluminum bronze alloy works great like ampco 18 or amco 45 or equvilant.(look it up)!! nearly indestructible and tougher than wood*_*_*_*_*_* lips. yet slippery under extreme loads and wear resistant. much harder than stanless wich is generally pretty soft unless you use a 400 series wich is heat treatable to get hard or a high nickel base alloy like 17-4 ph or 18-8. sorry just thought i'd throw some info at u guys and see were that takes us.
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I say try it and let us know if it works. John