JP2001271656A - Auxiliary machine driving unit for gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an auxiliary machine driving unit for gas turbine engines and reduce cost thereof, by reducing the number of part items. SOLUTION: The auxiliary machine driving unit A of the gas turbine engine to be mounted on the lower face of an engine casing formed into a nearly cylindrical shape is provided with a gear box 14 divided into an upper part and a lower part, a first and second auxiliary machine driving shafts 20 and 21 supported on a divided face p of the gear box 14. The first auxiliary machine driving shafts 20 is driven by the radial drive shaft 17 connected to the compressor shaft of a gas turbine engine, and the second auxiliary machine driving shafts 21 is driven by the first auxiliary machine driving shafts 20 via a drive spur gear 25 and driven spur gear 28. The first auxiliary machine driving shaft 20 is connected to a starter motor 31 and a fuel pump 33 are at both ends thereof, and the second auxiliary machine driving shafts 21 is connected to an oil pump 32 and a hydraulic pump 34 at both ends.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accessory drive unit mounted on an outer wall of an engine casing of a gas turbine engine and driving a plurality of accessories via a radial drive shaft and a gear box.

[0002]

2. Description of the Related Art Such an auxiliary drive unit for a gas turbine engine is known, for example, from JP-A-60-192828. This gas turbine engine includes two gear boxes mounted on the outer wall surface of the engine casing. Each gear box receives a driving force from a ring gear of a planetary gear mechanism provided inside the engine casing, and receives a plurality of gear boxes. The machine is to be driven.

A radial drive shaft penetrating an engine casing of the gas turbine engine from the inside to the outside is provided, and a driving force of the compressor shaft is transmitted to a gear box provided on an outer wall surface of the engine casing via the radial drive shaft. An accessory drive unit for driving a plurality of accessories supported by the gear box is also known. The gear box of this type of accessory drive unit generally has four accessory drive shafts, each of which drives one accessory.

[0004]

However, the former has not only increased number of parts, assembling man-hours and manufacturing cost due to the provision of two accessory drive units, but also increased labor required for maintenance. There is a problem of doing.
In the latter case, the four auxiliary drive shafts are each one.
Since a single accessory is driven, a large number of accessory drive shafts are required, which causes a problem that the gear box becomes large and the number of parts increases.

The present invention has been made in view of the above circumstances, and has as its object to reduce the number of parts of an auxiliary drive unit of a gas turbine engine to reduce the size and cost.

[0006]

In order to achieve the above object, an invention according to a first aspect of the present invention includes a radial drive shaft penetrating a substantially cylindrical engine casing from the inside to the outside, and the radial drive shaft. A gas turbine including a gear box that supports a plurality of driven accessory drive shafts and is mounted on an outer wall surface of an engine casing, and a plurality of accessories that are mounted on the gear box and driven by the accessory drive shafts In the engine accessory drive unit, the number of accessory drive shafts supported by the gear box is two, and the two accessory drive shafts are circumferentially separated along the outer wall surface of the engine casing. An auxiliary drive unit for a gas turbine engine, characterized in that the auxiliary drive unit is arranged in a manner as described above.

According to the above construction, the number of accessory drive shafts supported by the gear box and driven by the radial drive shaft is two, so that the number of accessory drive shafts is reduced to reduce the size of the gear box. can do. In addition, since the two auxiliary drive shafts are circumferentially spaced along the outer wall surface of the engine casing, the front area of the gear box protruding from the engine casing is reduced to reduce air resistance. Can be.

According to the invention described in claim 2,
In addition to the configuration of claim 1, the auxiliary device includes at least four components, a starter motor, a fuel pump, an oil pump, and a hydraulic pump, and the four auxiliary devices have four shaft ends of the two auxiliary device drive shafts. An accessory drive unit for a gas turbine engine is proposed, wherein the accessory drive unit is connected to and driven by a unit.

According to the above configuration, the four auxiliary drive shafts
By using four shaft ends to drive four accessories, a starter motor, a fuel pump, an oil pump, and a hydraulic pump, not only can two accessories drive shafts drive many accessories, but also The entire accessory drive unit including the gear box and the accessories can be reduced in size.

According to the third aspect of the present invention,
In addition to the configuration of claim 1, the gear box includes a first gear box half coupled to an outer wall surface of an engine casing, and a second gear box half coupled to the first gear box half. An auxiliary drive unit for a gas turbine engine is proposed, wherein the split surfaces of the first and second gear box halves are planes passing through the axes of the two auxiliary drive shafts.

According to the above configuration, the first gearbox half which is coupled to the outer wall surface of the engine casing, and the first gearbox half,
Since the gearbox is composed of the second gearbox half and the second gearbox half coupled to the gearbox half, the inside of the gearbox is exposed by simply removing the second gearbox half from the first gearbox half, thereby reducing maintenance. It can be done easily. Moreover, since the number of accessory drive shafts is two, the first and second
The split surface of the gear box can be made flat, and the processing of the split surface can be facilitated to reduce the processing cost.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 6 show an embodiment of the present invention. FIG. 1 is a rear view of an accessory drive unit of a gas turbine engine (a view taken along a line 1-1 in FIG. 2), and FIG. 2-2 of FIG.
FIG. 3 is an enlarged view of a main part of FIG. 2, and FIG.
4 is an enlarged cross-sectional view, FIG. 5 is a perspective view of the gearbox from which the first gearbox half has been removed, and FIG.
FIG. 6 is a sectional view taken along line 6-6 of FIG.

As shown in FIGS. 1 to 5, a gas turbine engine E for an aircraft includes a substantially cylindrical engine casing 11, and an auxiliary drive unit A is attached to a lower outer wall surface of the engine casing 11. . The accessory drive unit A includes a gear box 14 divided into an upper first gear box half 12 and a lower second gear box half 13, and the upper first gear box half 12 is an engine. The gear box mounting seat 11a formed on the lower surface of the casing 11 is fixed with four bolts 15..., And the second gear box half 13 is fixed on the lower surface of the first gear box half 12 with eight bolts 16. Fixed.

A radial drive shaft 17 driven by a compressor shaft (not shown) of the gas turbine engine E has
Engine casing 11 and gear box mounting seat 11
a and extends into the gear box 14. The radial drive shaft 17 includes a shaft portion 18 that extends obliquely rearward and downward with respect to the engine casing 11, and a spline-connected lower end of the shaft portion 18 to form the first gearbox half 12.
And a drive bevel gear 19 supported by a ball bearing 29 and a roller bearing 30.

The first auxiliary drive shaft 20 and the second auxiliary drive shaft 21 supported so as to be sandwiched between the first gear box half 12 and the second gear box half 13 have their longitudinal directions in the front-rear direction. (Parallel to the axis of the engine casing 11) and spaced apart by a predetermined distance in the left-right direction (the circumferential direction of the engine casing 11) along the lower outer wall surface of the engine casing 11. The split surface p of the first gear box half 12 and the second gear box half 13 is a flat surface, and the split surface p is the first accessory drive shaft 20.
And it is formed so as to pass through the axis of the second accessory drive shaft 21 (see FIG. 1).

The first auxiliary drive shaft 2 supported on a split surface p of the gear box 14 by a pair of ball bearings 22 and 23
0 is provided with a driven bevel gear 24 and a driving spur gear 25, and the driven bevel gear 24 is
7 meshes with the drive bevel gear 19. The second accessory drive shaft 21 supported by a pair of ball bearings 26 and 27 on the split surface p of the gear box 14 includes a driven spur gear 28. The driven spur gear 28 drives the first accessory drive shaft 20. It meshes with the spur gear 25. Accordingly, the driving force of the compressor shaft is changed from the driving bevel gear 29 of the radial drive shaft 17 to the driven bevel gear 24 of the first accessory driving shaft 20.
The driving spur gear 25 of the first auxiliary drive shaft 20 → the driven spur gear 28 of the second auxiliary drive shaft 21 transmits the path through the first auxiliary drive shaft 20 and the second auxiliary drive shaft 21 in the opposite directions. Drive.

A starter motor 31 and an oil pump 32 as accessories are mounted on the front surface of the gear box 14, and a fuel pump 33 and a hydraulic pump 34 as accessories are mounted on the rear surface of the gear box 14. The starter motor 31 and the fuel pump 33 are driven by the first accessory drive shaft 20, and the oil pump 32 and the hydraulic pump 34 are driven by the second accessory drive shaft 21.

The starter motor 31 drives the compressor shaft of the engine E via the first auxiliary drive shaft 20 and the radial drive shaft 17 when the gas turbine engine E is started. The drive shaft 20 is spline-coupled to the front end. After the start of the gas turbine engine E, the starter motor 31 is driven by the gas turbine engine E and functions as a generator.

The oil pump 32 is for supplying oil for lubricating the components of the gas turbine engine E and the gear box 14, and includes a gear box scavenge pump 36 and an engine scavenge pump 37, each of which is a circumscribed gear pump. , A feed pump 38. The gearbox scavenge pump 36 and the engine scavenge pump 37 have a common drive pump shaft 39 and a driven pump shaft 40, and a feed pump 38
Is provided with a dedicated drive pump shaft 41 and a driven pump shaft 42, the rear end of the former drive pump shaft 39 is splined to the front end of the second auxiliary drive shaft 21, and the front end of the former drive pump shaft 39 Is spline-coupled to the rear end of the latter drive pump shaft 41 so that the second auxiliary drive shaft 21
The set pumps 36, 37, 38 are driven. An oil pan 43 is connected to the lower surface of the second gear box half 13 with bolts 44 (see FIG. 4).

The fuel pump 33 is a gas turbine engine E
The pump shaft 45 is spline-coupled to the rear end of the first accessory drive shaft 20.

The hydraulic pump 34 generates hydraulic pressure for operating various hydraulic devices of the machine body. The hydraulic pump 34 is mounted on the rear surface of the gear box 14 via an adapter 46, and its pump shaft 47 is located behind the second auxiliary drive shaft 21. Splined at the end.

A generator 48 having a stator and a rotor is provided at the front of the fuel pump 33, that is, in the vicinity of the connection with the gear box 14. The stator is fixed to the inner surface of the casing 49 of the fuel pump 33,
The rotor is composed of a plurality of magnets 56 fixed to the outer periphery of the first accessory drive shaft 20.

The second auxiliary drive shaft 21 is provided with an oil separator 52 for separating only oil from oil containing air. An air inlet opening 21a... And an air outlet opening 21b are formed in the hollow second auxiliary drive shaft 21, and a number of radially arranged vanes 53a.
Are attached so as to surround the air inlet openings 21a. When oil containing air comes into contact with the vanes 53a of the rotor 53, centrifugal force is splashed to the outside in the radial direction, and only air is supplied to the air inlet openings 21a, the internal space of the second auxiliary drive shaft 21, Outlet opening 21b and air outlet 4 of adapter 46
It is discharged to the outside of the gear box 14 through 6a.

2 opposite to the gear teeth of the driven spur gear 28
Of the first gearbox half 12
And the second gear box half 13, and the speed sensors 54, 54 are connected to the control device via connectors 55, 55.

As described above, the gear box 14 has only two accessory drive shafts, the first accessory drive shaft 20 and the second accessory drive shaft 21, and these two first and second accessory drive shafts are used. 2
Since four starter motors, an oil pump 32, a fuel pump 33, and a hydraulic pump 34 are driven using the four shaft ends of the accessory drive shafts 20, 21, the number of parts of the gear box 14 is reduced. In addition to the above, the four accessory devices 31 to 34 can be compactly mounted on the front and rear surfaces of the gear box 14 to reduce the size of the accessory drive unit A as a whole. The first auxiliary drive shaft 20 and the second auxiliary drive shaft 21 are arranged in parallel with the axis of the engine casing 11 and are circumferentially separated from the axis along the outer wall surface of the engine casing 11. Since the gear box 14 is disposed at a minimum, the amount of protrusion of the gear box 14 from the outer wall surface of the engine casing 11 can be minimized to reduce the frontal area, thereby contributing to a reduction in air resistance.

Since the number of accessory drive shafts is two,
First gearbox half 12 supporting them so as to sandwich them
And the split surface p of the second gearbox half 13 can be a flat surface. As a result, the first gearbox half 12
In addition, machining of the split surface p of the second gear box half 13 is facilitated, which can contribute to reduction of machining cost.
Also, since the gear box 14 is divided into upper and lower parts, by removing the lower second gear box half 13 from the upper first gear box half 12, the inside of the gear box 14 is exposed to facilitate maintenance. It can be carried out.

FIG. 6 shows the operation of the gear box scavenge pump 36 of the oil pump 32. The drive pump gear 57 provided on the drive pump shaft 39 and the driven pump shaft 4
The driven pump gear 58 provided at 0 needs to rotate in the directions of arrows A and B in order to suck oil from below and discharge oil upward. Further, the driven pump gear 58 needs to be arranged on the opposite side of the starter motor 31 in order to avoid interference with the starter motor 31 connected to the first accessory drive shaft 20 (see FIG. 3). Therefore, the first
The rotation directions C and D of the accessory drive shaft 20 and the second accessory drive shaft 21 are set so as to satisfy the above two conditions.

The rotation directions of the engine scavenge pump 37 and the feed pump 38 are the same as those of the gear box scavenge pump 36.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, the auxiliary equipment driven by the first auxiliary equipment drive shaft 20 and the second auxiliary equipment drive shaft 21 is a starter motor 3
1. The present invention is not limited to the oil pump 32, the fuel pump 33, and the hydraulic pump 34.

[0032]

As described above, according to the first aspect of the present invention, the number of accessory drive shafts supported by the gear box and driven by the radial drive shaft is two,
The number of accessory drive shafts can be reduced to reduce the size of the gearbox. In addition, since the two auxiliary drive shafts are circumferentially spaced along the outer wall surface of the engine casing, the front area of the gear box protruding from the engine casing is reduced to reduce air resistance. Can be.

According to the second aspect of the present invention,
A starter motor, a fuel pump, an oil pump, and a hydraulic pump are used by using four shaft ends of two auxiliary drive shafts.
Since one accessory is driven, not only two accessories can be driven by two accessory drive shafts, but also the entire accessory drive unit including the gearbox and the accessories can be downsized. .

According to the third aspect of the present invention,
Since the first gearbox half connected to the outer wall surface of the engine casing and the second gearbox half connected to the first gearbox half constitute a gearbox,
By simply removing the second gear box half from the first gear box half, the inside of the gear box is exposed and maintenance can be easily performed. In addition, since the number of accessory drive shafts is two, the split surfaces of the first and second gear boxes can be made flat, so that the split surfaces can be easily processed and the processing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a rear view of an accessory drive unit of a gas turbine engine (a view taken along line 1-1 in FIG. 2).

FIG. 2 is a view taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. 1;

FIG. 5 is a perspective view of the gearbox from which the first gearbox half has been removed, as viewed obliquely from above.

FIG. 6 is a sectional view taken along line 6-6 in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Engine casing 12 1st gearbox half 13 2nd gearbox half 14 Gearbox 17 Radial drive shaft 20 1st auxiliary drive shaft (auxiliary drive shaft) 21 2nd auxiliary drive shaft (auxiliary drive shaft) 31 Starter motor (Auxiliary equipment) 32 Oil pump (Auxiliary equipment) 33 Fuel pump (Auxiliary equipment) 34 Hydraulic pump (Auxiliary equipment) p Splitting surface

Claims (3)

[Claims] An engine casing (1) having a substantially cylindrical shape.
1) Radial drive shaft (1) penetrating from inside to outside
7), a gear box (14) that supports a plurality of accessory drive shafts (20, 21) driven by the radial drive shaft (17) and is attached to the outer wall surface of the engine casing (11); A plurality of accessories (31, 3) attached to the box (14) and driven by the accessory drive shafts (20, 21).
2, 33, 34), comprising: an accessory drive shaft (2) supported by the gear box (14);
0, 21) are two, and the two accessory drive shafts (20, 21) are circumferentially spaced along the outer wall surface of the engine casing (11). A characteristic accessory drive unit for gas turbine engines. 2. The auxiliary machine includes at least a starter motor (31), a fuel pump (33), and an oil pump (32).
And four hydraulic pumps (34), and the four auxiliary machines are connected to and driven by four shaft ends of the two auxiliary machine drive shafts (20, 21). An accessory drive unit for a gas turbine engine according to claim 1. 3. A first gearbox half (12) coupled to an outer wall of an engine casing (11), said gearbox (14) and said first gearbox half (12).
A second gearbox half (13) coupled to the
The split surface (p) of each of the first and second gear box halves (12, 13) is a plane passing through the axis of the two accessory drive shafts (20, 21). 2. The accessory drive unit for a gas turbine engine according to claim 1.