Shaker table maintenance

[locovibe]

I removed our slip table to replace a hydraulic line on the center bearing. I see very little oil when I move the slip table back and forth. I set 1000 lbs on the slip table and it still moved very easily. The table was custom built by MRAD and Dataphysics. MRAD installed hydraulic lines on the sides of the slip table but Dataphysics replaced the bearings and instructed me not to hook up the lines to the sides on the slip table. I only have 3 hydraulic lines, 1 to each bearing. How much oil in normally seen on the sides of the granite when the pump is on? The oil is getting on the granite but not sure how?

Thanks!

 

[MikeHalloran]

Assuming that you're talking about a sliding granite table suspended on three hydrostatic bearings...

Such bearings normally have an orifice in them, intended to drop about half of the pump's pressure. The rest of the pressure drop is taken between the downstream side of the orifice, commonly a small hole or chamber in the center of the 'pad', and the bearing drain, comprising a groove extending all around the pad, and defining its active area.
The resulting oil film is normally very, very thin, so you wouldn't find much oil on the surface on disassembly.




Mike Halloran
Pembroke Pines, FL, USA

 

[IRstuff]

In fact, too thick a film will cause resonance interaction between the slip table and the oil itself.

TTFN

FAQ731-376

 

[locovibe]

Thanks,

I have only been around the shaker for about a year and no one to ask questions.

We have a fairly large head expander. I recently took and Random Vibration & Shock testing course by Wayne Tustin. He showed several instances of engineers filling their head expanders and fixtures with foam to reduce resonance. Have any of you tried this?

Thanks!

 

[MikeHalloran]

One thing that none of us here need is a head expander.

...

;-)



Mike Halloran
Pembroke Pines, FL, USA

 

[floattuber]

Unholtz Dickie told us there should be an oil gap of about 0.015-0.020 inches as measured with a feeler gauge.

The 32" diameter head expanders we have built by Baughn Engineering has some kind of expanding foam in between the stiffener spars.

I took a few classes at TTI, it's a very good school.