Lithium or polyurea for high temp slow bearings

[Shannow]

Hi,
looking at an application that has been problematic.

High load (150 tonnes), and slow speed (4RPM) application with thrust bearing and two guides (plain, leaded bronze), in an application that can see temperatures in the 100-150 range (higher if things play up.

Grease lines are about 50-60' long, and 10mmNB. Grease must by nature have a high level of solids (MoS2), and has traditionally been a Lithium soap. Grease is pumped metered quantities on a timer, a number of times per hour.

Grease lines block with hardened grease occasionally, which is bad mojo.

The group have been offered a polyurea based grease as an alternative. Still high MoS2 content.

Any thoughts on whether this is a better alternative ?

 

[Ramblejam]

On what basis was the current product selected?

With frequent relubrication being a non-issue, and possible excursions beyond 150°C, polyurea would be superior.

 

[Shannow]

Current product was OEM approved in the 80s, proposed product is OEM approved also.

 

[Ramblejam]

What's the current product?

 

[Shannow]

can't remember off top of my head...will need to come back to it.

 

[CT8]

The grease tube is 5 feet long or so and the grease dries up on occasion. Well this is totally out of my league but what does the mfg. recommend for a grease. I would first contact a grease MFG. to steer you in a proper direction for the best grease to use . Then if the type of grease will not correct the dried grease problem. A shorter line or running more grease through the lines to keep the grease wet.

 

[CT8]

50 or 60 feet!!!!

 

[Shannow]

Originally Posted By: CT8
50 or 60 feet!!!!


yep

 

[CT8]

Well then. The engineering and maintenance crews are on their own! I can see how the grease dries out. 50 feet is along distance. I read and mentally saw 50 to 60 inches Then the rpm and weight made me wonder , I had to go back and reread the post.

 

[MolaKule]

I would go with the polyurea grease, but those lines are going to have to purged of solids and old grease.

 

[Shannow]

Originally Posted By: MolaKule
I would go with the polyurea grease, but those lines are going to have to purged of solids and old grease.


Cool, that was my recommendation too after a couple days of pondering.