Turbocharger systems with direct turbine interfaces
View Patent ↗Turbine assemblies and related turbocharger systems having direct turbine interfaces are provided. One exemplary turbine assembly includes a first turbine housing having an outlet portion defining a fluid outlet of a first turbine and a second turbine housing having an inlet portion defining a fluid inlet of a second turbine, wherein at least a portion of the outlet portion radially surrounds at least a portion of the inlet portion to provide a direct interface from the fluid outlet of the first turbine to the fluid inlet of the second turbine in an axial direction.
1. A turbine assembly comprising:
a first turbine housing having an outlet portion defining a fluid outlet of a first turbine; and
a second turbine housing having an inlet portion defining a fluid inlet of a second turbine, wherein at least an exit portion of the outlet portion radially surrounds at least an entry portion of the inlet portion to provide a direct interface from the fluid outlet of the first turbine to the fluid inlet of the second turbine in an axial direction without any intervening ducting and a radial air gap without any intervening components between an inner surface of the exit portion of the outlet portion and an outer surface of the entry portion of the inlet portion.
2. The turbine assembly of claim 1 , wherein the first turbine comprises a radial turbine and the second turbine comprises an axial turbine.
3. The turbine assembly of claim 2 , wherein rotational axes of the radial turbine and the axial turbine are concentrically aligned in the axial direction.
4. The turbine assembly of claim 1 , wherein:
a first end of a seal is joined to an outer surface of the inlet portion; and
a second end of the seal is joined to an outer surface of the outlet portion.
5. The turbine assembly of claim 1 , further comprising a stator assembly housed within the inlet portion of the second turbine, the stator assembly including a diffuser cone portion extending from the second turbine in the axial direction into the fluid outlet.
6. The turbine assembly of claim 5 , wherein the exit portion of the outlet portion radially surrounds at least a portion of the diffuser cone portion and the entry portion of the inlet portion is disposed between the portion of the diffuser cone portion and the exit portion of the outlet portion.
7. The turbine assembly of claim 5 , wherein an inner surface of the inlet portion is contoured to correspond to a portion of the diffuser cone portion disposed within the fluid inlet.
8. A turbocharger system comprising:
a first compressor;
a first turbine coupled to the first compressor and having a first common rotational axis therewith;
a second turbine having an inlet inserted within an outlet of the first turbine to provide a direct fluid interface for gas flow from the first turbine to the second turbine without any intervening ducting and a radial air gap without any intervening components between an inner surface of an exit end portion of the outlet and an outer surface of an entry end portion of the inlet; and
a second compressor coupled to the second turbine and having a second common rotational axis therewith, wherein the first common rotational axis and the second common rotational axis are concentric.
9. The turbocharger system of claim 8 , further comprising a seal hermetically sealing the inlet of the second turbine with the outlet of the first turbine.
10. The turbocharger system of claim 9 , wherein the seal comprises a bellows structure expandable in an axial direction aligned with the first and second common rotational axes.
11. The turbocharger system of claim 8 , further comprising a stator assembly disposed within the inlet of the second turbine, wherein the stator assembly includes a diffuser cone portion extending into the outlet of the first turbine.
12. A turbocharger system comprising:
a first compressor;
a radial turbine having a first turbine wheel coupled to the first compressor via a first rotary shaft, the radial turbine comprising a first turbine housing defining a radial fluid inlet and an axial fluid outlet;
a second compressor;
an axial turbine having a second turbine wheel coupled to the second compressor via a second rotary shaft aligned with the first rotary shaft in an axial direction, the axial turbine comprising a second turbine housing defining an axial fluid inlet, wherein at least a portion of an axial outlet portion of the first turbine housing radially surrounds at least a portion of an axial inlet portion of the second turbine housing to provide a direct fluid interface between the axial fluid outlet and the axial fluid inlet without any intervening ducting and a radial air gap without any intervening components between an inner surface of the axial outlet portion and an outer surface of the axial inlet portion; and
a seal hermetically sealing the portion of the axial outlet portion to the second turbine housing.
13. The turbine assembly of claim 1 , wherein the inner surface of the exit portion of the first turbine housing directly faces the outer surface of the entry portion of the second turbine housing.
14. The turbine assembly of claim 1 , further comprising a bellows structure radially surrounding at least the exit portion of the first turbine housing and the entry portion of the second turbine housing, wherein:
a first end of the bellows structure is joined to the outer surface of the inlet portion;
a second end of the bellow structure is joined to an outer surface of the outlet portion; and
the bellows structure is flexible in an axial direction.
15. The turbine assembly of claim 1 , further comprising a bellows structure radially surrounding at least the portion of the inlet portion and the portion of the outlet portion, wherein:
a first end of the bellows structure is joined to the outer surface of the inlet portion;
a second end of the bellow structure is joined to an outer surface of the outlet portion; and
the bellows structure is flexible in an axial direction.
16. The turbine assembly of claim 1 , wherein:
the first turbine housing comprises a volute portion about a wheel of the first turbine; and
the outlet portion extends away from the wheel of the first turbine towards the second turbine in the axial direction by less than a radial fluid inlet defined by the volute portion.
17. The turbine assembly of claim 1 , wherein:
the outlet portion extends axially away from a first wheel of the first turbine towards the second turbine; and
the inlet portion extends from a second wheel of the second turbine towards the first turbine in the axial direction.
18. The turbine assembly of claim 1 , wherein:
an inner surface of the outlet portion of the first turbine includes a first recess for receiving the inlet portion of the second turbine; and
an outer surface of the inlet portion includes a second recess corresponding to the first recess.
19. The turbine assembly of claim 1 , wherein the radial air gap is configured to prevent the first turbine housing and the second turbine housing from contacting one another during operation.
20. The turbine assembly of claim 1 , wherein an outer circumference defined by the outer surface of the entry portion of the inlet portion is less than an inner circumference defined by the inner surface of the exit portion of the outlet portion to provide the radial air gap.