How it works: The track motor spool in an Excavator 

I've always wondered how this was accomplished so thanks for explaining. Nice to see the actual parts.

Almost 12 years on and you're still helping people learn. Thanks for answering my questions!

I have been wondering for so long how this worked! I imagined it had to be sometimes like this. Thanks for posting!

Thanks for explaining that. Great video. Very clever design. I always wondered how that was achieved.

tremendous video, ive being driving an excavator all week wondering how this happens

@willingtowork not a spool. That maybe what they call that down south, but the correct term is "rotary manifold" A spool is what the valve banks consist of, they stroke back and forth and are controlled by pilot hydraulic pressure. Those are directly behind the swing motor in this pictured Hitachi EX270LC-1 unit. I can't remember if there is a bulkhead welded between the swing drive and the valve banks.

Thank you for the video. I have been running heavy equipment since 2000 when I was 19 yrs old and have always tried to answer that question to people. I explained it like a banjo fitting, but really it's like 4 banjo fittings stacked. This will help.

We were discussing this earlier in the week trying to figure it out, nice one thanks

Is that spool dead center in the slew ring? And If so I'm also guess that when you showed it from the engine compartment, that big round piece to the left is the drive gear that mates to the slew ring.

thanks a lot for explaining this mechanism it was driving me crazy n confusing me how it works i did a lot of researches then i found your video thanks again bro

can you record a video of how the swing brake works? its very hard to find information on. :(

this video deserve to share everywhere

Thank you, I had wondered how this aspect of an excavator worked. Finally I know!

I randomly wondered about this a few minutes ago, now I know something, thanks, great explanation!

Been wondering this for a while so I googled it. It's basically a huge banjo bolt...

It is nice to see you have a locker bar for the top spinning port of the center joint, but my EX50urg has no locker, it twisted and broke a hose on spinning port at a very cold day, due to stiffness of cold fluid.

I wondered how this worked. Thank you for you video!

Great video, I saw the spindizzy ride at diggerland, which just spins round and round all day long, and asked how this worked, and they didn't know - your video shows this really clearly. I have to ask - how much does the spool cost ? Looks an expensive bit of machining !!

Thank you I always wondered how they didnt get the hoses twisted, Im guessing is the same thing for the electrical side? Thanks 👍😃

This is one of those things I never understood during my childhood and teenage years. I would think about it, but forget to ask whenever I met someone who could actually explain/demonstrate it. Thank you for providing a simple and easy to understand answer to one of my oldest questions! =D By the way, would someone care to explain how the hydraulic oil is "reversed" in the rotating centerpiece? It may be a silly question, but it's kind of bugging me now that I finally understand the first part..

Thanks! I never understood how the oil got to the undercarriage until now.

i have always called them swivels and depending on the type air/hydraulic swivel. i call the centre piece the swivel and the outer piece the swivel housing.

i thought it was something like this but you have answered a question that has got the better of me for years. thanks heaps

Thanks Lance. Very well explained.

Wauh !! this is great ... i have been an operator for more than six years now , and this thing always has given me an headache on how it works , imagne its gone to appoint of thinking tht magic is making this happen but thankyou for letting me know

Excellent video! Thank you.

So the fluid in one hose comes down and fills one "level" and so it can only exit one orifice on the bottom half no matter which way it faces. That's some extreme tolerances to not leak under that pressure. I'm sitting at a construction company with 3 of them and was curious how they moved independent of the upper half. Could make for a he'll of an amusement ride if you say in the bucket while spinning and moving forward.

Excellent video. Very clear explanation.

Always wondered how that worked. Excellent explanation as to how it works. Thanks

Thanks for sharing the knowledge

It helps a lot! Thanks!

So simple but so genius. Amazing!

Thanks buddy now i will sleep peacefully

Thanks for sowing how it works

thanks for the video, exactly what i needed to know. I have two more questions if anyone can help. 1) To run fluid to the hydraulic cylinders on the blade would you just have an extended version of this mechanism? 2) If you wanted to solve this same problem but for electrical wiring, is there a similar mechanism? thanks

Hi, Can operating on one track motor for a while upset the spool? I removed sun gear from my right side so I could continue to operate machine. Now I have put new motor in and it does not turn even though I can hear engine labouring.

Very educational, thumbs up for you guys wherever you from it dont matter.We need more talk like that,Regards from Papua New Guineaor should we say PNG

thank's for teardown excavator..... now i know they work,, nice video

The device being examined isn't involved with making the whole thing turn. It just solves the problem of how to get four hoses from the top part to the bottom part while allowing "infinite" turning. It turns on a "slewing bearing" - two rings, with ball bearings separating them. One ring attaches to the top, the other to the bottom. One ring will have gear teeth on it, the other part of the machine will turn using motors connected to a gear tooth engaged with the fixed gears on the bearing.

I am pleasantly surprised by the comments. Even though the narrator did not mention that each section of the swivel, rotary or live center is separated by seals in the outer housing apparently everyone figured that out for themselves.

@gangesexcavating I've always called them swivels.but I like Rotary manifold better..I'll use that from now on.lol..

How to repair hyundai wheel type back and forward no faction pls be inform thanks you

finally i can die in peace

That's for Track, what about wheel excavator, pressure for blade, out tigger, brakes, travel

It like the headphone jack 👍 1:51

thats awesome..... thanks i always wondered how that worked

Awesomesauce!

Great. Now would someone please invent a valve on a hose connector that releases when there is too much pressure instead the hose bursting randomly anywhere! Then we just lose some oil, the valve closes back when you stop overworking the part, you can refill and get back to work with less gusto this time. I'm surprised nobody's done it. This is like electricity without fuses.

We call it a hydrulic orbital unit in ireland

here's some terminology for you, rotary manifold. also for the "things" that drive the tracks, planetary track hub, probably a 3 stage with negative brake and most likely a radial piston hydraulic motor.

1) Yes, you would need two more ports on the top (or wherever you can fit them so long as the principle still works), and two more rings on the bottom. You are quite the machinist if you can make one. 2) Yes, a very similar design is used for those "Fixing a Retractable Cord Reel" youtube search 1:41 you can see the contactor rings where a tab would ride on each ring allowing for continuity while being able to spin continuously

Another great mysteries inside My mind has been solved

Now how would wires work with that

Thank you so much

Always wondered about that

That's awesome

so what makes the whole thing turn?

Thanka man, very informative. Also...he said orifices

That's for the explanation...

Thanks Sir Give Me More Videos Excavator

thanks!!

yeah nice video.

full fitting video.sir

Fake! I know for a fact you can only rotate it 15 times before it unscrews itself and the top half falls down, onto the ground, then your pay is docked! (just kidding that's actually brilliant!)

Answered my question .. thanks

l found my locker broken off so hoses suffers......

thanks .. now I know

That’s a lie, on this machine if you turn to the left 24 times you will unscrew yourself. On cats it’s 12 to the right and it unscrews.

not turn but drive :)