Another Chiller Teardown & Rebuild

[Tech Rob]

770 ton Trane CVHF, bearing failure and a worn oil seal


Removing the economizer


Economizer sealed up for storage to prevent rust


Rigging of suction elbow


Removing suction elbow


Suction elbow covered to prevent rust


Compressor and evaporator flanges covered to prevent rust and prevent debris from falling in


Preparing to remove suction cover


Removing suction cover


Rigging the suction cover down and a shot of one of the work-tables where all of the tools return when we are done with something


Checking the run-out of the 1st stage impeller

[Tech Rob]

This is where the inter-stage shaft seal mounts on the 1st stage diffuser


Looking at the motor journal bearing support with the oil seal, mounting plate, and internal oil line removed


Setting up the dial indicator to make sure we do not move the shaft too much when we remove the bearing and bearing support


Another shot of the dial indicator setup


The failed journal bearing


Dowel pins installed to make sure the bearing support goes back exactly where it was before


Removal of bearing support - we monitored the shaft at all times with the dial indicator as it could move no more than .003" in any direction


Another shot of the removed journal bearing support and the bad back oil seal


Inside the motor

[y7turbo]

Something wrong with the second post, I cant see the pictures, first post is ok.

[Tech Rob]

Something wrong with the second post, I cant see the pictures, first post is ok.

Fixed. This new site format is glitchy.

[y7turbo]

Fixed. This new site format is glitchy.

Works now, Thanks for sharing.

[Tech Rob]

Works now, Thanks for sharing.

Thanks for checking it out and commenting!

[y7turbo]

Any idea on what the weights were on the parts you removed?

[Tech Rob]

Economizer 840#
Suction elbow 700#
1st vane assy. 400#
Suction cover 1700#
Inter-stage 2000#

Also a couple of smaller items between 50# and 200#

[gravity]

that is cool! it looks like you know what your doing

[Tech Rob]

Thanks! My motto is "fake it until you make it"!!!

[y7turbo]

"fake it until you make it"!!!

[manny238]

Wow. thanks for sharing the pics. I would love to do a tear down like that. nice job!

[Nuclrchiller]

I've never seen that bearing bracket removed while the motor is still mounted to the discharge volute. Do you plan to replace the motor-to-volute o-ring? How about the discharge volute-to-condensor o-ring? Appreciate the pics. Very nice equipment room... once you get past the chilled water lines above the starter.

[Tech Rob]

I've never seen that bearing bracket removed while the motor is still mounted to the discharge volute. Do you plan to replace the motor-to-volute o-ring? How about the discharge volute-to-condensor o-ring? Appreciate the pics. Very nice equipment room... once you get past the chilled water lines above the starter.

It is a lot easier to do that front bearing bracket with the thrust bearings removed, or at the very least, with the thrust bearing support removed. It is even easier still to do it all with the motor sitting on a cart on the ground.

It is a nice, well lit mechanical room with a lot of clearance and room to work without interference. The guys and gals at this site work very hard to keep everything in good order.

[Freightshaker]

Thanks for sharing looks fun.

[milkyway]

Thanks! My motto is "fake it until you make it"!!!

Lol., cant fake that that too much., good job rob!!
Rob for president ,,

[milkyway]

So do u use a second chain fall for the shaft to pull the bearing off,(I am assuming)
To pull off the seal (journal) I only see one.

[Tech Rob]

Lol., cant fake that that too much., good job rob!!
Rob for president ,,

So do u use a second chain fall for the shaft to pull the bearing off,(I am assuming)
To pull off the seal (journal) I only see one.

Yes. First chain is to lift the shaft enough so you can remove the bearing support. Once you get it out far enough, you put the dial back on the shaft and put a chain behind the bearing support. Transferring the weight of the shaft from one chain to the other is the trickiest part of the whole job.

[AiResearch]

Very cool. Those of us DX guys dont get to see too many of these...disassembled anyway!

Any ideas as to the cause of bearing failure? Oil system blunder?

Thanks for sharing and keep em comin!

[Tech Rob]

Inside the oil tank. Up top is what is commonly called the foam breaker, although that's not really what it does. It's just a mesh screen. On the other side of it a vent line that vents the oil tank to the lowest pressure part of the system. On the back of the tank is the splash guard that covers the oil return from the journal bearing.


Here is what the oil pump and motor looks like with the tank head removed.


Pulled off the oil line to make sure there were no slugs of sealant or other blockages in the internal oil line since there is no other way to get to it once everything is re-assembled.


Here's the gear from the oil pump. The oil pump is a positive displacement gear pump similar to those used in large semi-hermetic reciprocating compressors.


This is the end of the oil pump that is directly coupled to the motor. Oil comes in through the top port and is discharged through the copper line attached to the bottom port.