# US 2008/0184694 A1 · Gas turbine with contrarotating hp and lp turbines

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- Number: US 2008/0184694 A1
- Document ID: US20080184694A1
- Status: Published application
- Kind: A1
- Application number: 12/026,033
- Filed: 2008-02-05
- Published: 2008-08-07
- Earliest claimed: 2007-02-07
- Assignees: Snecma
- Inventors: Jean-Michel Bernard Guimbard; Renaud Martet; Eric Schwartz
- Web page: https://patentgrep.com/patent/US20080184694A1

## CPC

- F02K 3/072: with counter-rotating {, e.g. fan} rotors
- F01D 1/26: traversed by the working-fluid substantially axially
- F02C 3/067: having counter-rotating rotors (F02C3/073 takes precedence)
- F05D 2240/12: Fluid guiding means, e.g. vanes
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00)
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A gas turbine with contrarotating HP and LP turbines comprises an LP turbine having a plurality of moving wheels alternating with nozzles, the moving wheels of the LP turbine rotating in a direction opposite to the direction of rotation of the moving wheel of the HP turbine, and an inter-turbine casing having inner and outer casing walls defining a stream passage between the HP and LP turbines together with arms extending across the passage between the inner and outer casing walls. The gas turbine does not have a nozzle or device for forming the function of deflecting the stream between the outlet from the HP turbine and the first moving wheel of the LP turbine. The HP turbine is advantageously designed to deliver a stream that gyrates in the inter-turbine casing.

## Claims

### Claim 1

A gas turbine comprising: a high pressure turbine; a low pressure turbine with a plurality of moving wheels alternating with nozzles, the moving wheels of the LP turbine rotating in a direction opposite to the direction of rotation of the moving wheel of the HP turbine; and an inter-turbine casing having inner and outer casing walls defining a stream passage between the HP and LP turbines with arms extending across the passage between the inner and outer casing walls;
the gas turbine not having a nozzle or device for having the function of deflecting the stream between the outlet from the HP turbine and the first moving wheel of the LP turbine.

### Claim 2 (depends on 1)

A gas turbine according to claim 1, wherein the HP turbine is designed to deliver a stream that gyrates in the inter-turbine casing.

### Claim 3 (depends on 2)

A gas turbine according to claim 2, wherein the general direction of the stream exiting the HP turbine forms an angle of not less than 20° relative to the axial direction of the turbine.

### Claim 4 (depends on 1)

A gas turbine engine fitted with a turbine according to claim 1.