Bearing seal on gear box

[Guillermo Dubosc]

Dear Friends
I ask you because the bearings of the gearboxes come with seals that prevent the lubricant from reaching the bearing. Does anyone have an explanation?
Thanks William

 

[Guillermo Dubosc]

I ask why?
the bearings of the gearboxes come with seals that prevent the lubricant from reaching the bearing. Does anyone have an explanation?
Thanks William