Axially segmented impeller

An impeller with an axial inlet in relation to an impeller axis for pressurising a fluid that comprises:

• a nose section comprising a first material that has a nose section central hub and multiple nose vane sections, each nose vane section extending from a leading edge to a generally radial nose section interface plane;
• a tail section comprising a second material different from the first material that has a tail section central hub and multiple tail vane sections, each tail vane section extending from a generally radial tail section interface plane to a vane tip;
• a coupling that joins the nose section central hub to the tail section central hub and aligns each one of the multiple nose vane sections with a corresponding one of the multiple tail vane sections with an axial gap between the generally radial nose section interface plane and the generally radial tail section interface plane.

An impeller with an axial inlet and a radial outlet in relation to an impeller axis for pressurising a fluid that comprises:

• a nose section comprising a steel alloy that has a nose section central hub and multiple nose vane sections, each nose vane section extending from a leading edge to a generally radial nose section interface plane;
• a tail section comprising a non-ferrous material that has a tail section central hub and multiple tail vane sections, each tail vane section extending from a generally radial tail section interface plane to a vane tip;
• a coupling that joins the nose section central hub to the tail section central hub and aligns each one of the multiple nose vane sections with a corresponding one of the multiple tail vane sections with an axial gap between the generally radial nose section interface plane and the generally radial tail section interface plane that is sufficient to allow for the difference in thermal expansion of the nose section and the tail section.