If you want two revolved features to have a common centerline, you can use the centerline axis from the existing feature as the axis of revolution for the feature you are currently constructing.
In the graphics window, with nothing selected, right-click to display the shortcut menu.
On the shortcut menu, point to Show All, and then click Reference Axes.
On the Home tab, in the Solids group, click the command for the revolved feature you want to construct.
Define the profile plane for the revolved feature.
When the profile window is displayed, on the Home tab, in the Draw group, click the Axis Of Revolution button.
Click the axis you displayed in step 1.
Continue to draw the revolved feature as usual.
Tip:
You can use the centerline axis of any revolved protrusion, revolved cutout, or hole as the axis of revolution for a new revolved feature.