Labyrinth seal and method with separately-formed seal portions

A method of providing an interlocking labyrinth seal for an aircraft engine having a housing that defines an aperture and a shaft extending along an axis of the shaft and passing through the aperture, the shaft being rotatable about the axis, comprising:

• attaching a base plate to the housing to form a seal against an outer periphery of the aperture in the housing, the base plate having a first opening with a first inner diameter;
• attaching a first annular insert to the base, the first annular insert having a first outer diameter disposed in a sealed relationship with the first inner diameter and further including a first plurality of fins disposed at a seal position;
• attaching an annular base onto the shaft extending through the aperture in the housing, the annular base having a second outer diameter;
• and
• attaching a second annular insert to the annular base, the second annular base having a second inner diameter disposed in a sealed relationship with the second outer diameter and further including a second plurality of fins disposed at the seal position to interlock with the first plurality of fins and form a sealed rotational interface.

A labyrinth seal for an aircraft engine having a housing that defines an aperture and a shaft extending along an axis of the shaft and passing through the aperture, the shaft being rotatable about the axis, comprising:

• a base plate having a sleeve structured to fit into the aperture of the housing, the base plate formed of a first composition of material and having a first opening with a first inner diameter;
• a first annular insert, the first annular insert formed of a second composition of material different from the first composition of material and having a first outer diameter structured to form a sealed interface with the first inner diameter and further including a first labyrinth seal element disposed at a seal position;
• an annular base structured to fit onto the shaft extending through the aperture in the housing, the annular base formed of a third composition of material and having a second outer diameter;
• and
• a second annular insert, the second annular insert formed of a fourth composition of material different from the third composition of material and having a second inner diameter structured to form a sealed interface with the second outer diameter and further including a second labyrinth seal element disposed at the seal position to interface with the first labyrinth seal element and form a sealed rotational interface.