JP2001041052A - Lubricating oil staying preventive structure of aircraft engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating oil staying preventive structure of an aircraft engine capable of improving soundness without making an oil reservoir even when a positional change is caused on the aircraft engine. SOLUTION: A tapered part 11 becoming larger in diameter from an end surface is formed toward a central part on an inside diameter part of a hollow rotation axis 6a positioned at an oil reservoir part where lubricating oil stays due to a positional change of an aircraft engine, and an oil discharge hole 12 passing through to the outside from the inside diameter part is formed on a large diameter side end part of this tapered part 11. When oil staying in the oil reservoir enters the tapered part 11 of the inside diameter of this hollow rotation axis 6a, centrifugal force works in accordance with rotation of the hollow rotation axis 6a, lubricating oil rises along the tapered part 11 by its component force, it can be discharged by centrifugal force from the oil discharge port 12 of the tapered part 11, and it is possible to prevent making of the oil reservoir. Consequently, it is possible to restrain rising of lubricating oil temperature and bearing temperature due to the positional change of the aircraft engine and to improve soundness against the positional change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing lubricating oil from accumulating in an aircraft engine. This prevents the temperature from rising.

[0002]

2. Description of the Related Art Aircraft engines undergo large changes in attitude compared with engines used on land or at sea, and soundness is required for all attitudes.

For example, in an accessory drive gearbox provided for driving accessories using the power of an engine, as shown in FIG. 2, power is supplied from a rotor 2 of an engine 1 to a power take-off assembly 3 and a radial drive shaft. The gear train 6 is transmitted to a gear train 6 in a gear box 5 through the gear train 4, and a fuel pump, a lubricating oil pump, a fuel boost pump, and the like as accessories are driven through the gear train 6. In addition, since the internal shape of the gear box 5 is complicated to mount the bearings 7 for supporting them, and a large amount of lubricating oil is used, as shown in FIG. An oil sump 8 that accumulates in a part of the box 5 is formed.

[0004] The formation of such an oil sump 8 causes problems such as an increase in the temperature of lubricating oil and bearings.

[0005] For this reason, conventionally, a pipe for discharging the accumulated lubricating oil is provided by devising the casting shape of the gear box 5 or the oil is forcibly discharged by an oil discharging pump.

[0006]

However, if the gear box itself is provided with a pipe made of casting to prevent the accumulation of oil, the casting becomes complicated, resulting in an increase in cost and instability of quality. There is a problem.

[0007] In addition, if an attempt is made to prevent the oil sump from being forcibly formed by the oil drain pump, it is necessary to increase the size of the oil drain pump, which causes a problem of an increase in weight and cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art, and prevents lubricating oil accumulation in an aircraft engine, which can improve soundness even if a change in attitude occurs in the aircraft engine. It seeks to provide structure.

[0009]

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, a lubricating oil collecting structure for an aircraft engine according to claim 1 of the present invention has an oil reservoir in which lubricating oil accumulates due to a change in attitude of the aircraft engine. A tapered portion whose diameter increases from the end face of the oil reservoir portion is formed on the inner diameter portion of the hollow rotary shaft located at the position, and the tapered portion penetrates outward from the inner diameter portion of the hollow rotary shaft at the large diameter side end portion. An oil drain hole is formed.

According to the structure for preventing lubricating oil accumulation in the aircraft engine, the inner diameter of the hollow rotary shaft located at the oil accumulation portion where the lubricating oil accumulates due to a change in the attitude of the aircraft engine is increased in diameter from the end face of the oil accumulation portion. A tapered portion is formed, and at a large-diameter side end of the tapered portion, an oil drain hole penetrating outward from the inner diameter portion of the hollow rotary shaft is formed, and a tapered portion is formed on the inner diameter of the hollow rotary shaft. As a result, when the oil accumulated in the oil sump enters the tapered portion, centrifugal force acts with the rotation of the hollow rotary shaft, and the centrifugal force rises along the tapered portion by the component force, and the end of the tapered portion is discharged. The oil is discharged from the oil hole by centrifugal force to prevent oil pooling.

According to a second aspect of the present invention, there is provided a structure for preventing lubricating oil from accumulating in an aircraft engine, wherein a spiral groove is formed along the conical surface of the tapered portion to promote oil drainage. It is characterized by the following.

According to the structure for preventing the accumulation of lubricating oil in an aircraft engine, a spiral groove for promoting oil drainage is formed along the conical surface of the tapered portion. The oil is urged to drain from the oil drain hole, so that no more oil pools are formed.

According to a third aspect of the present invention, there is provided an aircraft engine lubricating oil accumulation preventing structure according to the first aspect, wherein a linear groove is formed along the inclined surface of the tapered portion to promote oil drainage. It is characterized by the following.

According to this structure for preventing the accumulation of lubricating oil in an aircraft engine, a linear groove is formed along the inclined surface of the tapered portion to promote oil drainage. The oil is urged to drain from the oil drain hole, so that no more oil pools are formed.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a lubricating oil accumulation preventing structure for an aircraft engine according to the present invention.

FIG. 1 is a sectional view showing an embodiment in which a lubricating oil accumulation preventing structure for an aircraft engine according to the present invention is applied to an auxiliary drive gear box.
(B) shows the state after the posture change.

In the accessory drive gearbox to which the lubricating oil accumulation preventing structure 10 for an aircraft engine is applied, bearings 7 are mounted in recesses 5a and 5b of a gearbox 5 made of a casting, and a hollow gear train 6 rotates. The shaft 6a is supported and rotatable.

In this accessory drive gear box,
It is known in advance that the oil sump 8 is formed due to a change in the attitude of the aircraft.
The recess 5a on the right side is located below due to the change in posture, and an oil reservoir 8 is formed.

In the lubricating oil accumulation preventing structure 10 for the accessory drive gear box, the oil accumulation 8
A tapered portion having a small diameter at the end and a large diameter at the center is provided on the inner diameter portion from the end of the hollow rotary shaft 6a located at the portion where the is formed to the center of the hollow rotary shaft 6a which is not immersed in oil. An oil drain hole 12 is formed on the outer side of the end of the tapered portion 11 on the central portion side to penetrate the hollow rotary shaft 6a in and out.

It is sufficient that at least one oil drain hole 12 is formed, but it is preferable to form the oil drain holes 12 at equal circumferential intervals in consideration of the rotational balance of the hollow rotary shaft 6a and the like. Individually formed.

In the lubricating oil accumulation preventing structure 10 for an aircraft engine thus configured, the hollow rotary shaft 6
When the lubricating oil accumulates in the concave portion 5a of the gear box 5 where the right end of the a is located, the lubricating oil also enters the tapered portion 11 of the inner diameter of the hollow rotary shaft 6a, and the rotation of the hollow rotary shaft 6a is stopped. Accordingly, a centrifugal force acts on the lubricating oil in the tapered portion 11.

Then, since the inner diameter of the hollow rotary shaft 6a is inclined by the tapered portion 11, a component force of the centrifugal force along the inclined surface acts on the lubricating oil. To rise.

When the lubricating oil rises to the center-side end of the tapered portion 11, it reaches the oil draining hole 12, and the lubricating oil is discharged to the outside of the hollow rotary shaft 6a by the centrifugal force itself, and the lubricating oil accumulated in the concave portion 5a is discharged. It is not sucked and discharged one by one and accumulated.

As a result, it is possible to prevent the temperature of the lubricating oil from locally increasing and the bearing temperature from increasing.

As described above, the lubricating oil is discharged from the oil sump 8 by utilizing the pumping action caused by the centrifugal force acting along the tapered portion 11 of the inner diameter of the hollow rotary shaft 6a. Therefore, if a spiral groove (spiral groove) is formed on the conical surface of the tapered portion 11 and the lubricating oil rises along the spiral groove with the rotation of the hollow rotary shaft, the lubricating oil is more efficiently Can be discharged from the oil drain hole 12.

Similarly, by forming a straight groove along the inclined surface of the tapered portion 11, the hollow rotary shaft 6a
If the lubricating oil rises along the straight groove by the centrifugal force caused by the rotation of, the lubricating oil can be efficiently discharged from the oil drain hole 12 as compared with the case where there is no straight groove.

In the above-described embodiment, the auxiliary drive gear box has been described as an example where the oil reservoir is formed due to the change in attitude of the aircraft engine. However, the present invention is not limited to this.
It can be applied to other parts.

[0028]

As described above in detail with one embodiment, according to the lubricating oil accumulation preventing structure for an aircraft engine according to the first aspect of the present invention, lubricating oil accumulates due to a change in attitude of the aircraft engine. A tapered portion having a larger diameter from the end face of the oil reservoir portion is formed on the inner diameter portion of the hollow rotary shaft located in the oil reservoir portion, and the tapered portion has a large-diameter end portion outside the inner diameter portion of the hollow rotary shaft portion. A tapered portion is formed on the inner diameter of the hollow rotary shaft, so that when oil accumulated in the oil sump enters the tapered portion, centrifugal rotation occurs with the rotation of the hollow rotary shaft. The force acts and rises along the tapered portion due to the component force, and can be discharged by the centrifugal force from the oil discharge hole at the end of the tapered portion, so that the oil pool can be prevented.

As a result, it is possible to improve the soundness against the attitude change, for example, it is possible to suppress the rise of the lubricating oil temperature and the bearing temperature due to the attitude change of the aircraft engine.

According to the lubricating oil accumulation preventing structure for an aircraft engine according to the second aspect of the present invention, the spiral groove for promoting oil drainage is formed along the conical surface of the tapered portion, so that the centrifugal force is reduced. The rise of oil due to the component force can be promoted by the spiral groove and can be discharged from the oil discharge hole, and the generation of oil pool can be suppressed more efficiently.

Further, according to the lubricating oil accumulation preventing structure for an aircraft engine according to the third aspect of the present invention, a linear groove is formed along the inclined surface of the tapered portion to promote oil drainage. The rise of the oil due to the component force can be promoted by the linear groove and can be discharged from the oil discharge hole, so that the oil pool can be prevented more efficiently.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment in which a lubricating oil accumulation preventing structure for an aircraft engine according to the present invention is applied to an accessory drive gear box, wherein (a) shows a state before a change in posture, and (b) shows a change in posture. The following are shown respectively.

FIG. 2 shows an example of an auxiliary drive gear box to which the lubricating oil accumulation preventing structure for an aircraft engine according to the present invention is applied;
(A) is a schematic configuration diagram shown together with an engine, (b) is a schematic perspective view, and (c) is a schematic sectional view.

3A and 3B are cross-sectional views in which a part of a conventional accessory driving gear box is extracted, in which FIG. 3A shows a state before a posture change, and FIG. 3B shows a state after a posture change.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Rotor 3 Power take-off assembly 4 Radial drive shaft 5 Gear box 5a Depression 6 Gear train 6a Hollow rotating shaft 7 Bearing 8 Oil sump 10 Aircraft engine lubricating oil sump prevention structure 11 Tapered portion 12 Oil drain hole

Claims (3)

[Claims] 1. A tapered portion having a larger diameter from an end face of the oil reservoir is formed in an inner diameter portion of a hollow rotary shaft located in an oil reservoir in which lubricating oil accumulates due to a change in attitude of an aircraft engine. A lubricating oil accumulation preventing structure for an aircraft engine, wherein an oil drain hole penetrating outward from an inner diameter portion of the hollow rotary shaft is formed at a large diameter end. 2. The structure for preventing lubricant oil accumulation in an aircraft engine according to claim 1, wherein a spiral groove is formed along the conical surface of said tapered portion to promote oil drainage. 3. An aircraft engine lubricating oil accumulation preventing structure according to claim 1, wherein a straight groove is formed along the inclined surface of said tapered portion to promote oil drainage.