I am not familiar with this machine type. This bearing design is unusual. The fact that the thrust bearing is a fixed pad design that is built as part of the radial bearing seems strange to me. We would normally only use a bearing like this if there was very little predicted thrust. We would call it more of a thrust bumper that you might see on the ends of the radial bearings in a double-helical gearbox with no net thrust.
I see a couple of things in the photo that draw my attention. The pressure dam in the radial bearing seems to be packed with something dark. This suggests contamination in the lube oil. The thrust face damage could be suggestive of overload, inadequate lubrication, contaminated lubrication, poor oil selection. I would check for any sources of unexpected or excessive thrust loads. Without any knowledge about this machine, I would consider coupling spacing, differential thermal expansion, balance piston/disk design or balance line routing.
I can’t see how oil gets into this bearing. I see a pressure dam in the radial bearing, but no oil distribution grooves or a port for introduction of oil into the bearing. I would expect to see some ports or passages to introduce oil between the pads on the thrust face.
I would check the oil system for filter design and rating. I would check for piping that would allow oil to bypass the filter. I would verify that the oil used is the correct viscosity for this machine design and speed.
I would not expect to solve this problem with a change to babbitt grade.
If you could provide details about the machine configuration and the oil system, we would have a better chance to help you understand this.
Johnny Pellin
