JPS63106335A - Gas turbine engine - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to gas turbine engines, and more particularly to turbofan engines with counter-rotating low pressure devices.

BACKGROUND OF THE INVENTION This invention is filed in pending United States Patent Application Serial No. 437.9.
No. 23 and its partially pending application No. 728.466.

The above-cited US patent application describes a counter-rotating turbofan driven by a counter-rotating power turbine. A feature of this US patent application is the type of power turbine and the ratio of the average flow radius of this turbine to the average flow radius of the gas generator. This is necessary, in part, to allow for lower fan tip speeds and/or higher turbine blade speeds.

Under design conditions such as , it may be desirable to reduce the average flow radius of the power turbine.

In the example of the above-cited US patent application, reducing the average flow path radius of the power turbine increases fan tip speed and thus reduces engine efficiency.

It is an object of this invention to provide a new and improved counter-rotating turbofan engine with high shunt ratio.

Another object of this invention is to provide a new and improved turbofan engine with counter-rotating boost compressors.

Another object of this invention is to provide a new and improved turbofan-engine having a front-mounted counter-rotating fan and boost compressor driven by two counter-rotating shafts.

Summary of the invention In this invention, a gas turbine engine will be described.

This engine consists of a gas generator that acts to generate combustion gas, a power turbine, a fan section, and a boost compressor (b
ooster comprossoj). The power turbine has first and second counter-rotating rows of vanes operative to rotate the first and second drive shafts, respectively. The fan portion has a first row of fan blades connected to a first drive shaft and a second row of fan blades connected to a second drive shaft. A boost compressor has a first row of compressor blades connected to a first drive shaft and a second row of compressor blades connected to a second drive shaft.

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a gas turbine engine 10 according to an embodiment of the present invention. The engine 10 has a longitudinal centerline axis 12 and an axis 12
It has an annular casing 14 coaxially arranged around the casing. The engine 10 includes a gas generator core engine 16, which is connected to a compressor 18, a combustor 20, and a high pressure turbine 2.
2 in one stage or in multiple stages, all of which are arranged coaxially around the longitudinal axis or centerline 12 of the engine 10 and in series with respect to the axial flow. An annular drive shaft 24 secures compressor 18 and high pressure turbine 22 together.

Gas generator 16 operates to generate combustion gas. Pressurized air from compressor 18 is mixed with fuel in combustor 20 and ignited, thus generating combustion gases. A high pressure turbine 22 extracts some work from this gas and compressor 1
Drive 8. The remaining combustion gas is transferred to the column 2 of the support member 28.
6 and is discharged from the gas generator 16 to the power turbine 30 .

The power turbine 30 is mounted on a suitable bearing 3 in a hub member 36 of the frame.
4 has a first annular drum rotor 32 rotatably mounted thereon. A first rotor 32 has a plurality of first rows 38 of turbine blades axially spaced apart and extending radially inwardly therefrom.

Power turbine 30 also has a second annular drum-shaped rotor 40 disposed radially inwardly of first rotor 32 and first row of blades 38 .

The second rotor 40 then has a plurality of radially outwardly extending and axially spaced second rows 4 of turbine blades.
I have 2. A second U-trochanter 40 is rotatably mounted on the first shaft 44 by a differential bearing 46 .

Each of the first and second rows 38.42 of turbine blades includes:
It is comprised of a plurality of circumferentially spaced turbine blades, with first rows 38 of blades being spaced alternately from second rows 42 in a comb shape. The combustion gases flowing through the row of vanes 38.42 drive the first and second rotors 32.40 in opposite directions, the rotors rotating at substantially the same speed.

First and second drive shafts 44.48 are secured to the first and second rotors 32.40, respectively. For this reason, the first and second rotors 32,40 are connected to the first and second drive shafts 4, respectively.
4.48. a drive shaft 44,48 is arranged coaxially with respect to the centerline 12 of the engine 10;
It extends forward inside the gas generator 16.

Additionally, the engine 10 has a front fan section 52. A fan portion 52 is disposed radially inwardly of an annular fan duct 54 suitably secured to casing 14 by struts 56. The fan portion 52 is connected to the first drive shaft 4
4 has a first row of fan blades 58 connected to the front end 60 of the fan.

Similarly, the fan portion 52 is connected to the forward end 64 of the second drive shaft 48.
It has a second row of fan blades 62 connected to the fan.

Each of the first and second fan blade rows 58,62 is comprised of a plurality of circumferentially spaced fan blades. The fan blade rows 58,62 are counter-rotating to produce relatively high fan efficiency and propulsion efficiency with generally low absolute tip velocities in each fan blade row. Rows of fan blades 58 and 62 are fan ducts 54
It extends radially outward.

It should be appreciated that the rows 62 of counter-rotating fan blades act to remove the swirl or circumferential component of the air applied by the row 58 of counter-rotating fan blades. By doing so, strut 56 is not an exit guide vane in the sense that this swirl need not be removed by the strut. Therefore, in order to support the duct 54, a relatively small number of columns 56 are required.
only need.

A strut 56 is located axially forward of the core engine 20. Therefore, the engine 10 can be supported as close to the fan blade rows 58 and 62 as possible.

Furthermore, the engine 10 has a boost compressor 66.

Boost compressor 66 has a first annular rotor 68 extending radially outwardly therefrom and including a plurality of axially spaced first compressor blade rows 70 . Boost compressor 66 has a rotor 68 and a second annular rotor disposed radially outwardly from the first compressor blade row 70. Extending from the rotor 72 are a plurality of axially spaced and radially inward rows 74 of second compressor blades.

A rotor 68 connects the fan blade row 58 and the first drive shaft 44
is fixed to the front end 60 of. Similarly, a rotor 72 is secured to the fan blade row 62 and the forward end 64 of the second drive shaft 48 .

Each of the first and second compressor blade rows 70.74 is
Composed of a plurality of compressor blades spaced apart in the circumferential direction, a first row of blades 70 is connected to a respective second row of blades 74.
They alternate and are separated from each other. Compressor blade row 70
．． 74 is the opposite rotation, and the compressor 1 of the gas generator 16
It is located in a core duct 76 that leads to 8.

A counter-rotating boost compressor 66 provides a significant pressure increase to the air entering the core gas generator 16.

The advantage of driving the fan blade row and the compressor blade row by the same drive shaft is that energy extraction from the power turbine 30 is optimized. Power turbine to shaft 4
4.48 Without a boost compressor stage driven through
A separate compressor with an additional shaft and drive turbine is required. Furthermore, the absence of a boost compressor stage limits the overall pressure ratio of the engine, resulting in poor efficiency. A rotary booster produces sufficient pressure rise despite the slow fan speed. The counter-rotating nature of the compressor blade rows 70,74 requires fewer compressor blade rows than would be required for a single, low speed compressor driven from only one shaft. You can.

FIG. 2 shows a fan section 52 and a boost compressor 6 of another embodiment.
6 is shown. In the boost compressor 66, the rotor 68 is connected to the rotor 72.
It is shaped so that it is placed further outward in the radial direction. To this end, the first compressor blade row 70 extends radially inwardly from the rotor 68 and the compressor blade row 74 extends radially inwardly from the rotor 68.
Extending radially outward from 2.

It will be apparent to those skilled in the art that this invention is not limited to the specific embodiments illustrated.

It will be appreciated that the engine 10 of this invention is essentially a separate core engine 20 at the center with two counter-rotating turbines at one end and two counter-rotating fans at the other end. I want to be Counter-rotating turbines and fans are not intermixed with the central core engine.

To achieve thrust reversal, the device can be equipped with a standard thrust reversal device. Instead of this, as is known,
A variable pitch mechanism can be used and incorporated into the device.

The dimensions, proportions, and structural relationships shown in the drawings are given by way of example only, and these illustrations are not to be construed as actual dimensions or proportions or structural relationships that may be used in the opposite turbofan engine of this invention. Please be aware of this.

The invention is limited only by the scope of the claims, and various modifications and full and partial equivalents may be employed within the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of one type of high shunt ratio counter-rotating turbofan engine of the present invention, and FIG. 2 is a schematic illustration of a boost compressor for another type of high shunt ratio turbofan engine of the present invention. This is a schematic diagram. Explanation of main symbols 20: Gas generator 30: Power turbine 38. 40: Row of turbine blades 44. 487 Drive shaft 52: Fan section 58. 62: Row of fan blades 66: Boost compressor 70. 74: Compressor row of feathers

Claims (1)

[Scope of Claims] 1) An integrated gas generator that operates to generate combustion gas; and a gas generator located rearward of the gas generator that operates to rotate the first and second drive shafts, respectively. a power turbine including a first and second row of counter-rotating turbine blades; a first and second row of fan blades forward of the gas generator and connected to the first drive shaft; a fan section having a second row of fan blades connected to a drive shaft; a first row of compressor blades located forward of the gas generator and connected to the first drive shaft; a boost compressor including a second row of compressor blades connected to a drive shaft of the gas turbine engine. 2) a gas generator having a core compressor, combustor and turbine in series with the flow and operative to generate combustion gases, and an annular casing arranged coaxially around the centerline of the engine; a power turbine having first and second rows of counter-rotating turbine blades operative to rotate first and second drive shafts, respectively; a first row of fan blades connected to the drive shaft, and a second row of fan blades arranged axially rearward from the first row and connected to the second drive shaft, each row having a second row of fan blades connected to the second drive shaft. a fan portion having a plurality of blades extending close to the fan duct and operative to generate a fan flow; a first row of compressor blades connected to the first drive shaft and the second row of compressor blades; a boost compressor with a second row of compressor blades connected to the drive shaft of the gas turbine engine. 3) The gas turbine engine according to claim 2, which includes a strut that is disposed axially forward of the core compressor and fixes the duct to the casing. 4) The gas turbine engine according to claim 2), wherein the first and second rows of oppositely rotating turbine blades rotate at substantially the same speed. 5) a first rotor having a gas generator operative to generate combustion gases and a plurality of first rows of turbine blades extending radially inwardly therefrom and a plurality extending radially outwardly therefrom; a second rotor having rows of second turbine blades, wherein the first and second rows of turbine blades are alternating and comb-shaped; The rotors rotate in opposite directions, and the first and second
a power turbine that acts to drive each of the drive shafts of the
a fan portion having a first row of fan blades connected to the first drive shaft and a second row of fan blades connected to the second drive shaft; and a compressor connected to the first drive shaft. A gas turbine engine having a boost compressor having a first row of compressor blades and a second row of compressor blades connected to the second drive shaft. 6) The gas turbine engine according to claim 5, wherein the gas generator is a separate device from the power turbine, fan section, and boost compressor. 7) a gas generator operative to generate combustion gases; and a first turbine rotor having a plurality of rows of first turbine blades extending radially inwardly therefrom and extending radially outwardly therefrom; a second turbine rotor having a plurality of rows of second turbine blades;
a power turbine having counter-rotating turbine rotors operative to drive first and second drive shafts, respectively; a first row of fan blades connected to said first drive shaft and said second row of fan blades connected to said first drive shaft; a fan section having a second row of fan blades connected to a drive shaft of the fan; and a plurality of first rows of compressor blades connected to the first drive shaft and extending radially outwardly therefrom. a first compressor rotor having a rotor, and a plurality of second compressor rotors connected to the second drive shaft and extending radially inwardly therefrom.
a boost compressor including a second compressor rotor having a row of compressor blades. 8) In the gas turbine engine according to claim 7), the second row of the fan blades is the first row of the fan blades.
A gas turbine engine located axially aft of the row, the fan section operative to generate a fan flow. 9) A gas turbine engine as claimed in claim 7) in which the gas generator is not interdigitated with respect to the fan section, boost compressor and power turbine. 10) The gas turbine engine according to claim 7, wherein the first and second drive shafts rotate at approximately the same speed.