JPH07224680A - Bearing lubricator of outboard main shaft - Google Patents

Abstract

PURPOSE:To provide a bearing lubricator that is able to lubricate two bearings, supporting an outboard main shaft, uniformly and accurately. CONSTITUTION:Lubricating oil to be lubricated to two bearings 2 and 2 supporting a shaft 5 as an outboard main shaft is fed out of an oil filler port 4 at the left end of this shaft 5. This lubricating oil is fed to an inner diametral oil sump part at the inside of an inner spacer 3 held between both inner rings of these bearings 2 and 2 out of another oil filler port 10 from an inner diametral oil groove 7 in the shaft 5. This port 10 is installed in an intermediate point of these bearings 2 and 2, through which the lubricating oil is uniformly fed to both these bearings 2 and 2 existing in an equidistance from this oil filler port 10 by way of the inner diametral oil sump part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device applied to a support bearing for a cantilevered main shaft of a small gas turbine engine for helicopters.

[0002]

2. Description of the Related Art In a small gas turbine engine, it is essential to increase the speed of the main shaft in order to achieve high performance, and in order to reliably lubricate the high speed main shaft support bearing, it is necessary to use centrifugal force to supply oil from the oil supply port of the main shaft. The inner diameter shaft hole lubrication method is generally adopted. However, since the cantilever support can structurally supply oil to the inner diameter of the shaft only from one direction, the lubricating oil is supplied to the bearing from one direction by utilizing the oil groove on the inner diameter of the shaft for two or more bearings. FIG. 2 shows a small gas turbine engine equipped with such a conventional bearing lubrication device.

In FIG. 2, reference numeral 5 denotes a shaft, which is supported by two main shaft bearings 2 and 2 which are spaced from each other by an inner spacer 3. A tie bolt 6 penetrates the shaft 5. Reference numeral 1 is a bearing tightening nut. An oil supply port 4 is formed in the bearing tightening nut 1, and lubricating oil for the main shaft bearings 2, 2 is supplied from the oil supply port 4 through an inner diameter oil groove 7 in the shaft 5. That is, the lubricating oil supplied from the oil supply port 4 flows in the inner diameter oil groove 7 of the shaft 5 and the oil supply port 8 formed in the shaft 5,
It is supplied to the respective main bearings 2 and 2 through 9.

[0004]

As can be seen in the small gas turbine engine described above, when the support bearing for the high speed main shaft of the cantilevered support structure is lubricated by the inner diameter shaft hole lubrication system utilizing centrifugal force, it is structurally Since it is possible to supply oil to the inner diameter of the main spindle only from one direction, the same oil groove or different oil grooves are used for two or more bearings to supply lubricating oil in series or in parallel from one direction. In this case, in order to evenly lubricate each bearing, measures such as changing the size of the oil groove depending on the location or calculating the lubrication hole of the bearing to be lubricated first by an appropriate calculation are made. It was difficult to evenly refuel.

The present invention provides a lubrication device for two main shaft bearings that support the main shaft of a cantilevered support structure having a simple structure and capable of reliably and uniformly supplying lubricating oil to each bearing. The challenge is to provide.

[0006]

SUMMARY OF THE INVENTION According to the present invention, two main shaft bearings for supporting a cantilevered main shaft are securely and evenly constituted by a centrifugal force generated by the rotation of an inner diameter oil groove of the main shaft through an oil supply port. In order to solve the above-mentioned problem of refueling in, the following configuration is adopted. That is, in the lubricating device according to the present invention, the inside of the inner spacer sandwiched between the inner rings of the two main shaft bearings to be lubricated serves as the inner diameter oil reservoir.

Then, a structure is adopted in which an oil supply port of the main shaft is provided at an intermediate point between both main shaft bearings in the inner diameter oil reservoir, and oil is supplied to the main shaft receivers equidistant from the oil reservoir through the inner diameter oil reservoir. To do. In the lubricating device according to the present invention, the oil supply port of the main shaft is thus located at the intermediate point of the inner diameter oil reservoir inside the inner spacer, and the line loss of the lubricating oil path from this intermediate point to both bearings is the same. I am trying.

[0008]

Since the lubricating device according to the present invention employs the above-described structure, the lubricating oil supplied to the inner diameter oil groove of the main shaft from one direction is subjected to the centrifugal force to the inner diameter oil reservoir portion of the inner spacer with respect to the main shaft. It is supplied at the midpoint of the axial distance between the support bearings. By setting the distance to both bearings and the groove size to be the same with this intermediate point as the base point, the line loss of the route through which the lubricating oil is guided to each bearing becomes the same.

As described above, since the line loss up to both bearings is the same, the lubricating oil flowing out from the inner diameter oil groove of the main shaft to the inner diameter oil sump inside the inner spacer overflows from the inner diameter oil sump and is evenly distributed to both bearings. Supplied to bearings. Even when the main shaft is not horizontal and has some vertical inclination, at high speed rotation, the lubricating force by centrifugal force is much larger than the lubricating force by gravity, and therefore the lubricating device according to the present invention lubricates both bearings evenly. It is possible to do

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A lubricating device according to the present invention will be specifically described below based on an embodiment shown in FIG. Similar to the embodiment shown in FIG. 2, the embodiment shown in FIG. 1 is a case in which the present invention is applied to the main shaft bearings of a small gas turbine engine, and corresponds to the portion constituting the conventional device shown in FIG. The same reference numerals are given to the parts to be described for the sake of brevity.

In the apparatus shown in FIG. 1, an oil supply port 10 for letting the lubricating oil flow out by centrifugal force from an inner diameter oil groove 7 formed in a shaft 5 as a main shaft is used as an intermediate portion of the inner spacer 3. That is, the inside of the inner spacer 3 sandwiched by the inner rings of the main shaft support bearings 2 and 2 to be lubricated is used as the inner diameter oil reservoir, and the inner diameter oil reservoir is located at the intermediate point between the two main shaft support bearings 2 and 2. The filler opening 10 of the shaft 5 is opened. An oil groove is formed so that the lubricating oil overflowing from the inner diameter oil reservoir flows to the bearings 2 and 2 on both sides.

In the thus configured lubricating apparatus shown in FIG. 1, the lubricating oil supplied from the oil supply port 4 of the bearing tightening nut 1 moves in the inner diameter oil groove 7 of the shaft 5 by the centrifugal force of the shaft 5. At the midpoint between the two main shaft support bearings 2, the oil flows out from the oil supply port 10 formed in the shaft 5 to the oil reservoir of the inner diameter of the inner spacer 3. The lubricating oil that has flowed out to the inner diameter oil reservoir overflows and is supplied to both bearings 2 and 2 through the oil grooves to both bearings 2 and 2 to lubricate both bearings 2 and 2.

The position of the oil supply port 10 flowing out from the shaft 5 to the inner diameter oil reservoir of the inner spacer 3 is the same distance from both bearings 2 and 2, and the oil overflowed from the inner diameter oil reservoir inside the inner spacer 3 is the bearing. By selecting the same geometrical shape of the paths (oil grooves) leading up to 2 and 2, it is possible to reliably and evenly supply oil to both bearings 2 and 2.

The present invention has been specifically described above based on the illustrated embodiments, but the present invention is not limited to these embodiments and the shape and structure thereof are within the scope of the present invention shown in the claims. It goes without saying that various changes may be added to the. For example, although the main shaft of a small gas turbine engine has been described as an example in the above-described embodiments, the present invention is not limited to this, and can be widely used as a lubricating device for a bearing that supports a cantilevered main shaft.

[0015]

According to the present invention, when a cantilever-supported main shaft support bearing of a small gas turbine engine or the like, which is structurally required to supply oil in one direction, adopts an inner diameter shaft hole lubrication system, lubricating oil is supplied from the inner diameter oil groove of the main shaft. The oil supply port for supplying oil is located at the middle point of the inner spacer, and the structure is such that oil is supplied to both bearings from there through uniform oil grooves, and the structure is simple, and the two opposing bearings are evenly and reliably oiled. A device capable of performing the above is provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing a lubricating device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a conventional lubricating device.

[Explanation of symbols]

 1 Bearing Tightening Nut 2 Spindle Support Bearing 3 Inner Spacer 4 Oil Filling Port 5 Shaft 6 Tie Bolt 7 Inner Diameter Oil Groove 10 Oil Filling Port

Claims (1)

[Claims] 1. A lubricating device configured to supply lubricating oil to two main shaft bearings supporting a cantilever type main shaft through an oil groove of an inner diameter of the main shaft, through an oil supply port, and by centrifugal force due to its rotation. An inner diameter of the inner spacer sandwiched between the inner rings of the two main shaft bearings serves as an inner diameter oil reservoir portion, and an oil supply port of the main spindle is provided at an intermediate point between the both spindle bearings in the inner diameter oil reservoir portion.
A lubricating device for a bearing of a cantilever type main shaft, characterized in that both main shaft bearings, which are equidistant from the oil supply port, are evenly supplied with oil through the same inner diameter oil reservoir.