Damn. meant ANY better seals? doesn't seem that i can edit the title.
Few years back picked up help with manual pages from folks on this site (thank you eveyrone) and finally got around to taking the swing box out of my Hitachi EX60 URG.
It stretched the capacity of my shop crane but we got it done. I pulled the hydraulic motor and planetary castings as one. the weight was the problem, it was the height to clear the machine with the lift.
In the end, I had to disassemble anyway to change the bearings which had disaggregated in situ after the seal let go for good (or i guess that would be for worse).
I've used it principally as a crane for the intervening year but I got a couple digging projects coming up that are going to require actually be able to swing.
Thankfully, the bearings are standard, one of the races even came out in one piece with a Koyo label and number right on the edge.
The other one I can infer from measuring the outside cup diameter and inside bore and using the same koyo 'line'.
I'm actually finding the Koyos anyway but there are SKF and FAG equivalents available. I'm trying to interpret the suffixes on the bearing numbers. I find some that have a C3 designation which according to SKF means an additional 15 micrometers of radial internal clearance. no sure that makes a lot of difference one way or another.
the local bearing house stocked ball bearings, not spherical rollers, which even if they would be appropriate don't have the same height. but i can find plenty of the spherical roller bearings online and just trying to figure how much the fine print after the numerical designation matters.
In my case I'm looking at Koyo 21311 and 22313.
And on seals. I believe the seal is a 120x150x18. It seems to have a single lip but had some kind of felt at the inserted side, perhaps as a simple secondary seal/wipe. I have two problems. There is a sleeve pressed onto the shaft that the seal rides on. the surface has been modestly marked and i feel like i should have maybe 10 to 20 thousandths or so machined off of it, but the nominal seal tolerances suggest within 4 thousandths. Is there such a thing as an extra reach seal. i don't reckon i'm going to find a 1mm smaller seal. don't know if i could find a 115x150x18 and just have it machined down a little more.
and i'm wondering on seal type if i can substitude a double lip. we're talking very low rpms, but i imagine that the lateral forces exerted over time lead to minor eccentric displacement during operation.
of if there is another seal type that is more forgiving in this environment. It seems like a weak point in design. I've known plenty of folks with lots of different brands who had trouble with this seal.
Thanks,
brian
Few years back picked up help with manual pages from folks on this site (thank you eveyrone) and finally got around to taking the swing box out of my Hitachi EX60 URG.
It stretched the capacity of my shop crane but we got it done. I pulled the hydraulic motor and planetary castings as one. the weight was the problem, it was the height to clear the machine with the lift.
In the end, I had to disassemble anyway to change the bearings which had disaggregated in situ after the seal let go for good (or i guess that would be for worse).
I've used it principally as a crane for the intervening year but I got a couple digging projects coming up that are going to require actually be able to swing.
Thankfully, the bearings are standard, one of the races even came out in one piece with a Koyo label and number right on the edge.
The other one I can infer from measuring the outside cup diameter and inside bore and using the same koyo 'line'.
I'm actually finding the Koyos anyway but there are SKF and FAG equivalents available. I'm trying to interpret the suffixes on the bearing numbers. I find some that have a C3 designation which according to SKF means an additional 15 micrometers of radial internal clearance. no sure that makes a lot of difference one way or another.
the local bearing house stocked ball bearings, not spherical rollers, which even if they would be appropriate don't have the same height. but i can find plenty of the spherical roller bearings online and just trying to figure how much the fine print after the numerical designation matters.
In my case I'm looking at Koyo 21311 and 22313.
And on seals. I believe the seal is a 120x150x18. It seems to have a single lip but had some kind of felt at the inserted side, perhaps as a simple secondary seal/wipe. I have two problems. There is a sleeve pressed onto the shaft that the seal rides on. the surface has been modestly marked and i feel like i should have maybe 10 to 20 thousandths or so machined off of it, but the nominal seal tolerances suggest within 4 thousandths. Is there such a thing as an extra reach seal. i don't reckon i'm going to find a 1mm smaller seal. don't know if i could find a 115x150x18 and just have it machined down a little more.
and i'm wondering on seal type if i can substitude a double lip. we're talking very low rpms, but i imagine that the lateral forces exerted over time lead to minor eccentric displacement during operation.
of if there is another seal type that is more forgiving in this environment. It seems like a weak point in design. I've known plenty of folks with lots of different brands who had trouble with this seal.
Thanks,
brian
swing box andy better seals? and bearing tolerance [hitachi EX60 URG)]
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