I have never seen a bearing housing quit like that before. Have you looked up from the bottom, between the two bolts and see if there isn't a set screw or two that hold that cover onto the bearing if none, the start to just pry those covers off,, I think those are just covers that set over the outside race of the bearing.
I think the inside race of the bearing is just sitting against a step in the shaft that keeps it from going in to far. There should be set screw some where on that bearing, clean some grease off and investigate.... Grandpa.