JP2002081326A - Intermediate part support device of radial drive shaft of engine for aircraft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve bending rigidity of a support member for holding a bearing at an intermediate position of a radial drive shaft. SOLUTION: An accessory gear box is mounted in a nacelle disposed via a strut 5, around an engine body 4, rotation of a rotating shaft of the engine body 4 is transmitted to the accessory gear box via the radial drive shaft 9 disposed in the strut 5. The bearing 12 supported at the intermediate position of the radial drive shaft 9 is attached to the tip of the support member 14 mounted on the back wall part 5a of the strut 5 at its base end. A spigot pin 16 is projectedly provided on the tip surface of the support member 14. A socket hole 17 engaging with the spigot pin 16 is formed in a block 18 provided inside a front wall part 5b of the strut 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate support device for a radial drive shaft for transmitting a rotational force of an engine body to an accessory gear box for driving an accessory of an aircraft engine.

[0002]

2. Description of the Related Art As shown in FIGS. 3A and 3B, an aircraft engine (here, a turbofan engine having a high bypass ratio) has a compressor 1 for compressing air.
A combustor 2 for injecting fuel into the compressed air to burn it, and an engine body 4 having a turbine 3 driven to rotate by the combustion gas and transmitting the rotating force to the compressor 1. A nacelle 6 is provided around the engine body 4 via a strut 5 so that the intake air is bypassed, and the engine body 4 drives a large fan 7 located at the front of the engine body 4 so as to supply air to the nacelle 6.
The engine is operated by increasing the bypass ratio (engine bypass flow rate / engine body flow rate).

In the aircraft engine, an accessory gear box 8 for driving an auxiliary machine such as a hydraulic pump may be mounted in a nacelle 6 located outside a fan 7. In this case, a radial drive shaft is provided. 9 is disposed so as to reach the inside of the nacelle 6 from the position of the rotation axis of the engine body 4 through the strut 5 and to connect the inner end of the radial drive shaft 9 and the rotation axis (high-speed side) of the engine body 4 to a bevel gear mechanism 10. And the outer end of the radial drive shaft 9 and the input shaft 8a of the accessory gearbox 8 are connected by a bevel gear mechanism 11
, And the rotation of the rotation shaft of the engine body 4 is transmitted to the accessory gear box 8 via the bevel gear mechanism 10, the radial drive shaft 9, and the bevel gear mechanism 11. Note that the radial drive shaft 9
The inner end and the outer end are connected to the bevel gear mechanism by splines so that they can be removed during maintenance.

[0004] When the accessory gear box 8 is mounted outside the large fan 7 as described above, the radial drive shaft 9 is inevitably lengthened, so that the rotation speed at which the critical speed is low is low. It becomes a number. Therefore, in order to increase the critical speed of the radial drive shaft 9, the bearing 12 is usually arranged at an intermediate position as shown in FIG. 3B, but this bearing 12 is taken out of the strut 5 at the time of maintenance. Up to now, the base end has been connected to the rear wall 5a of the strut 5 because of the necessity.
The distal end of a support member 14 which is detachably attached to the hole 15 provided in the hole with a bolt 13 from the outside is projected to the inside of the strut 5, and the bearing 12 is held at the distal end of the support member 14. I was trying to make it.

[0005]

However, in the intermediate support method of the radial drive shaft 9 as described above, since the support member 14 is cantilevered, the rigidity of the support member 14 in the compression and tension directions can be sufficiently increased, but the bending is not performed. There is a limit to increasing directional rigidity. Radial drive shaft 9
It has been found that when the bearing 12 is arranged at an intermediate position between the two, the critical speed of the radial drive shaft 9 greatly changes with a change in the radial spring constant of the bearing 12. In this case, the critical speed becomes low due to the influence of the low rigidity in the bending direction, and resonance of the radial drive shaft 9 may occur in the operation region.

Accordingly, the present invention seeks to increase the bending rigidity of a support member holding a bearing at an intermediate position of a radial drive shaft so that the critical speed of the radial drive shaft can be out of the operating range of the engine. Is what you do.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, a nacelle is arranged around a main body of an engine via a strut, and an accessory gear box mounted in the nacelle is provided with an internal gear. A bearing is arranged at an intermediate position of the radial drive shaft of an aircraft engine adapted to transmit the rotation of the engine main body through the inserted radial drive shaft, and the bearing is disposed at a rear end of the strut on a rear wall side. A block having a socket hole for fitting the spigot pin, the spigot pin being fixed to the tip of the support member detachably attached, and the spigot pin being fixed to the tip surface of the support member so as to protrude forward. Is provided inside the front wall of the strut, and the spigot pin is spigot-coupled to the socket hole. To.

Since the support member is supported at both ends, the bending rigidity as the displacement in the radial direction can be increased.

Also, instead of fixing the spigot pin at the tip of the support member and providing the socket hole in the block, the spigot pin is protruded rearward in the block, and the socket hole is provided in the tip surface of the support member. May be adopted.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B show an embodiment of the present invention. Similar to the aircraft engine shown in FIGS. 3A and 3B, a fan 7 is provided at a front position. A nacelle 6 for suctioning bypass airflow is disposed around the engine body 4 via a strut 5, and an accessory gear box 8 mounted in the nacelle 6 is used to control the rotation of the rotation shaft of the engine body 4 in the strut 5. The bearing 12 is disposed at an intermediate position of the radial drive shaft 9, and the bearing 12 is inserted into a hole 15 of a rear wall 5 a of the strut 5. Support member 1 with detachable mounting
In the configuration that is held at the tip of 4,
A block 18 in which a spigot pin 16 is attached to the front end surface of the support member 14 so as to protrude forward, and a socket hole 17 for fitting the spigot pin 16 is provided corresponding to the position of the support member 14.
Are integrally provided inside the front wall portion 5a of the strut 5,
The spigot pin 16 is spigot-coupled to the socket hole 17 to support the intermediate position of the radial drive shaft 9.

With the above structure, the support member 1
4 can be supported at both ends. In this case, since the tip end side of the support member 14 is a spigot connection,
Although the rigidity of the support member 14 in the compression and tension directions is almost the same as that of the related art, since the radial displacement of the spigot joint is restricted, the rigidity in the bending direction can be increased. Therefore, by improving the bending rigidity, the critical speed of the radial drive shaft 9 can easily be set outside the engine operation range, and the occurrence of resonance can be prevented. At the time of maintenance, as in the past,
Since the support member 14 can be attached and detached by removing and attaching the bolt 13, the assemblability is not impaired at all.

FIG. 2 shows another embodiment of the present invention. In the structure similar to that of the embodiment shown in FIGS. 1A and 1B, a spigot pin Instead of providing the socket hole 17 in the block 18 provided inside the front wall portion 5b of the strut 5, a spigot pin 16 is protruded rearward from the block 18 and the spigot pin 16 is fitted. Socket hole 1
7 is provided on the distal end surface of the support member 14.

In the embodiment of FIG. 2, FIG.
The same operation and effect as those of the embodiment (b) are exhibited.

In the above embodiment, the case where the number of the spigot pins 16 is one is shown. However, a plurality of spigot pins 16 may be used, and various modifications may be made without departing from the gist of the present invention. Obviously you can get it.

[0016]

As described above, according to the radial drive shaft intermediate support device for an aircraft engine of the present invention, an accessory gear box in which a nacelle is disposed around an engine body via a strut and mounted in the nacelle. A bearing is disposed at an intermediate position of the radial drive shaft of the aircraft engine which transmits the rotation of the engine body via a radial drive shaft inserted through the strut, and the bearing is disposed on a rear wall of the strut. A base member is detachably attached to a support member, the base member is held at the distal end of the support member, and a spigot pin is fixed to the tip surface of the support member so as to protrude forward, and the spigot pin is fitted. A block with a socket hole of is provided inside the front wall of the strut,
The spigot pin is inserted into the socket hole, or the spigot pin is fixed to the tip of the support member, and instead of the socket hole in the block, the spigot pin projects rearward from the block. However, since the support member has a configuration in which a socket hole is provided in the distal end surface portion, the bending rigidity of the support member can be increased, whereby the critical speed of the radial drive shaft can be set outside the engine operation region. In addition, it is possible to prevent the resonance of the radial drive shaft in the operating region, and that the connecting portion between the spigot pin and the socket does not impair the detachability of the support member, so that the assemblability is not impaired. Demonstrates excellent effects.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a radial drive shaft intermediate support device for an aircraft engine of the present invention,
(A) is a cut side view, and (B) is a view taken in the direction of arrows AA in (A).

FIG. 2 is a cut-away side view showing another embodiment of the present invention.

FIG. 3 shows an example of an aircraft engine.
1 is an overall schematic view, and FIG. 2B is an enlarged sectional view of a portion B in FIG.

[Explanation of symbols]

 Reference Signs List 4 engine body 5 strut 5a rear wall 5b front wall 6 nacelle 8 accessory gear box 9 radial drive shaft 12 bearing 14 support member 16 spigot pin 17 socket hole 18 block

Claims (2)

[Claims] A nacelle is disposed around an engine body via a strut, and the rotation of the engine body is transmitted to an accessory gearbox mounted in the nacelle via a radial drive shaft inserted into the strut. A bearing is disposed at an intermediate position of the radial drive shaft of the aircraft engine, and the bearing is held at a distal end of a support member having a base end detachably attached to a rear wall side of the strut, and A spigot pin is fixedly mounted on the distal end surface of the support member so as to protrude forward, and a block having a socket hole for fitting the spigot pin is provided inside the front wall of the strut. Radial for an aircraft engine, characterized in that it has a configuration adapted to be spigot-coupled to the engine Live shaft intermediate support device. 2. Instead of fixing a spigot pin at the tip of the support member and providing a socket hole in the block,
The radial drive shaft intermediate support device for an aircraft engine according to claim 1, wherein a spigot pin protrudes rearward from the block, and a socket hole is provided in a tip end portion of the support member.