Forward-swept impellers and gas turbine engines employing the same

Patent metadata

Field	Value
Publication number	US-2016238018-A1
Application number	US-201514623761-A
Country	US
Kind code	A1
Filing date	Feb 17, 2015
Priority date	Feb 17, 2015
Publication date	Aug 18, 2016
Grant date	—

Abstract

Embodiments of a forward-swept impeller are provide, as are embodiments of a gas turbine engine containing a forward-swept impeller. In one embodiment, the gas turbine engine includes a shaft and a forward-swept impeller mounted to the shaft. The forward-swept impeller includes, in turn, an inboard impeller section, an outboard impeller section circumscribing the inboard impeller section, and a plurality of hub flow paths extending over the forward-swept impeller from the inboard impeller section to the outboard impeller section. The plurality of hub flow paths each have a flow path exit that is tilted in a forward direction, as taken along a line tangent to the flow path exit.

First claim

What is claimed is:

1 . A gas turbine engine, comprising:
a shaft having a rotational axis; and a forward-swept impeller mounted to the shaft, the forward-swept impeller comprising:
an inboard impeller section;
an outboard impeller section circumscribing the inboard impeller section; and
a plurality of hub flow paths extending over the forward-swept impeller from the inboard impeller section to the outboard impeller section and each having a flow path exit that is tilted in a forward direction, as taken along a line tangent to the flow path exit.

2 . The gas turbine engine of claim 1 wherein the forward-swept impeller has a free ring radius, and wherein the forward-swept impeller further comprises an annular interface formed between inboard impeller section and the outboard impeller section, the annular interface concentric with the rotational axis and having a radius equal to the free ring radius.

3 . The gas turbine engine of claim 2 wherein the forward-swept impeller has a first Center of Gravity (CG), wherein the outboard impeller section has a second CG, and wherein the second CG is offset from the first CG in a forward direction by a predetermined amount AX OFF .

4 . The gas turbine engine of claim 3 wherein the plurality of hub flow paths each have an axial length of AX FLOW as taken along the rotational axis, and wherein AX OFF is at least 10% AX FLOW .

5 . The gas turbine engine of claim 1 wherein the line tangent to each flow path exit forms an acute angle θ with a radius of the forward swept impeller.

6 . The gas turbine engine of claim 5 wherein 1°<θ<20°.

7 . The gas turbine engine of claim 5 further comprising a diffuser positioned radially outboard of the forward-swept impeller and receiving airflow discharged therefrom, the diffuser having a flow passage tilted in a forward direction by an angle substantially equivalent to θ.

8 . The gas turbine engine of claim 1 further comprising a shroud circumscribing the forward-tilted impeller and having a downstream portion curling in a forward direction.

9 . The gas turbine engine of claim 1 further comprising a diffuser positioned radially outboard of the forward-swept impeller and configured to receive compressed airflow discharged therefrom, the diffuser having a flow passage with a leading edge axially offset in a forward direction relative to a forward-most point of the hub flow paths.

10 . A gas turbine engine comprising:
a shaft having a rotational axis; and an impeller mounted to the shaft, the impeller comprising:
an inboard impeller section having a first center of gravity (CG); and
an outboard impeller section circumscribing the inboard impeller section and having a second CG, the outboard impeller section tilted in a forward direction proximate an outer diameter of the forward-swept impeller such that the second CG is offset from the first CG in a forward direction by a predetermined amount AX OFF reducing deformation of the forward-swept impeller during operation of the gas turbine engine.

11 . The gas turbine engine of claim 10 further comprising a plurality of hub flow paths extending from the inboard impeller section to the outboard impeller section and each having a flow path exit, at least a portion of the outboard impeller section tilted in a forward direction such that a line tangent to the flow path exit forms an acute angle θ with a radius of the forward swept impeller.

12 . The gas turbine engine of claim 11 further comprising a diffuser outboard of the impeller and positioned to receive the compressed airflow discharged from the exducer portion, the diffuser is tilted in a forward direction by a tilt angle substantially equivalent to θ.

13 . The gas turbine engine of claim 11 wherein the impeller has a free ring radius, and wherein the impeller further comprises an annular interface formed between inboard impeller section and the outboard impeller section, the annular interface concentric with the rotational axis and having a radius equal to the free ring radius.

14 . The gas turbine engine of claim 11 further comprising a shroud circumscribing the impeller and having a downstream portion curling in a forward direction.

15 . A forward-swept impeller, comprising:
an inboard impeller section; an outboard impeller section circumscribing the inboard impeller section; and a plurality of hub flow paths extending from the inboard impeller section to the outboard impeller section and each having a flow path exit that is tilted in a forward direction, as taken along a line tangent to the flow path exit.

16 . The forward-swept impeller of claim 15 wherein the forward-swept impeller has a free ring radius, and wherein the forward-swept impeller further comprises an annular interface formed between inboard impeller section and the outboard impeller section, the annular interface concentric with a rotational axis of the forward-swept impeller and having a radius equal to the free ring radius.

17 . The forward-swept impeller of claim 16 wherein the forward-swept impeller has a first Center of Gravity (CG), wherein the outboard impeller section has a second CG, and wherein the second CG is offset from the first CG in a forward direction by a predetermined amount AX OFF .

18 . The forward-swept impeller of claim 17 wherein the plurality of hub flow paths each have an axial length of AX FLOW as taken along a rotational axis of the forward-swept impeller, and wherein AX OFF is at least 10% AX FLOW .

19 . The forward-swept impeller of claim 15 wherein the line tangent to each flow path exit forms an acute angle θ with a radius of the forward swept impeller.

20 . The forward-swept impeller of claim 19 wherein 1°<θ<20°.

Assignees

• Honeywell Int Inc

Inventors

• Conner Richard David
• Barton Michael Todd
• Gebre-Giorgis Yoseph
• Kington Harry Lester
• Repp John

Classifications

• F05D2220/32

  in gas turbines · CPC title

• F04D29/321

  for axial flow compressors · CPC title

• F05D2240/60

  Shafts · CPC title

• F01D9/04

  forming ring or sector · CPC title

• F05D2240/12

  Fluid guiding means, e.g. vanes · CPC title