oil Bath lubrication

Oil bath lubrication is where the oil level is actually doing the lubrication of the moving parts, where the moving parts are partially submerged in the oil.
Ring lubrication is where the oil level is at or lower that the moving parts, and a ring is intended to dip into the oil and, by the rotation of the shaft, sends oil splashing around and onto the moving parts. Rings have inherent problems though with slippage, metal wear, and travel up and down the shaft.
Disc lubrication is similar to ring lubrication but utilizes a disc instead of a ring. The disc is firmly affixed to the shaft to eliminate problems associated with rings. The disc is trimmed to dip approximately 1/4" in the oil, which the level is generally below the moving parts. Similar to the ring, by the rotation of the shaft, sends oil splashing around and onto the moving parts. There are many kinds of discs and materials but flexible discs allow easy installation.

Hope this helps...

Indeed, it helped, so by your explanation, splash lubrication should be the same as ring/disc lubrication. But Noria´s wall chart distinguishes the three types of systems into: "Bath lubricated plain bearing", "ring-lubricated bath oiler" and "splash lubricated gearing". I is that the designation is dependent on the mechanic system? I hope a further explanation can be given in order to uniformize all these designations.