Mounting assembly of two coaxial shafts

In the layout of two concentric shafts (15,16) a sleeve (38) surrounding the shafts carries two sealing joints (23,39). A bearing (18) supports the external line of shafts near the front end and a bearing retaining nut (19) is screwed on the front end. A spacer (40) having an adjustment part (42) slides around the external line of shafts and is tightened between the nut and the bearing. The sealing joint associated with the external line of shafts rubs on an airtight bearing surface (41) placed around the nut.