HYDRO Gates: Using Self Lubricated Bearings

 

Using self-lubricated bearings on radial gates

On these gate arms, the hydro project owner is using self-lubricated spherical bearings embedded with a polytetrafluoroethylene lubricant. These bearings are resistant to corrosion and do not present concerns regarding oil leakage into the water.

Gates are subjected to high specific loads so the bearings must be of sufficient strength to withstand this load. Second, gates may have long periods with no operation, which makes them susceptible to corrosion. Third, use of an oil-based product to lubricate the gate's bearings poses risks of leakage.

To address these challenges, Empresas Publicas de Medellin (EPM) decided to install DB spherical bearings manufactured by GGB of Thorofare, N.J., at its 660-MW Porce 3 plant in Colombia.

DB bearings are self-aligning spherical bearings that feature a stainless steel inner ring and an axially-split aluminum-bronze alloy outer ring embedded with a polytetrafluoroethylene (PTFE) lubricant.

The bearings have a low coefficient of friction, good wear resistance, long service life, and corrosion resistance, GGB says.

The dam at this project, which will be commissioned in 2010, features an open-channel spillway controlled by four radial gates.

These gates are 11 meters high by 14 meters wide.

For this application, the bearings will be subjected to radial loads as high as 12,000 kilo-Newtons.

When the gates open and close, the bearings will rotate 70 degrees in 90 minutes at operating temperatures of 0 C to 40 C.