A high-speed rotor bearing chamber with an oil-gas separation device

Abstract

The present invention discloses a high-speed rotor bearing chamber with an oil-gas separation device. The bearing chamber is divided into two front and rear oil collecting ring chambers with the bearing and the turbine rear bearing frame web as the boundary, and an oil-gas separation device located at the outer edge of the bearing chamber is provided. The oil-gas separation device includes a graphite seal ring mounting seat, a ring chamber oil-gas separator and a turbine rear bearing frame. Under the driving action generated by the high-speed rotation of the rotor, the oil-gas mixture passes through the oil-gas separation device at high speed. Due to the different densities of oil and gas, the separation of the oil-gas mixture is achieved. By dividing the bearing chamber into front and rear oil collecting ring chambers, the present invention reduces the flow space of the oil-gas mixture, which is beneficial to the return of lubricating oil, and uses the oil-gas separation device to separate the lubricating oil and air from each other, thereby preventing the lubricating oil from staying in the bearing chamber for a long time, ensuring that the lubricating oil can fully accumulate and flow to the oil return pipe, and thus being smoothly absorbed, improving the oil return efficiency.

Description

Technical Field

[0001] The present invention belongs to the field of the structural design of the bearing chamber of an aero-gas turbine engine, and relates to a high-speed rotor bearing chamber with an oil-gas separation device. Background Art

[0002] In an aero-engine, lubricating oil is delivered to the working surfaces of moving mechanisms such as bearings and gears, taking away the frictional heat generated by high-speed rotation and the heat transferred from surrounding high-temperature parts, and forming a continuous oil film between the raceway and rollers of the bearing and between the meshing tooth surfaces, thus playing a lubricating role. After the lubricating oil completes the lubrication of the bearing, it is radially thrown out by the bearing and enters the oil collecting ring chamber. Under the action of centrifugal force, the lubricating oil in the oil collecting ring chamber flows radially to the edge position and then flows into the oil return chamber below the oil collecting ring chamber under the action of gravity, and finally is discharged through the oil return pipe. Therefore, the lubricating oil has the characteristic of being recyclable. There is a certain amount of air in the lubricating oil system. Driven by the high-speed rotation of the rotor, the air will also rotate at a high speed circumferentially, and then mix with the lubricating oil in the bearing chamber, so that the lubricating oil and air in the bearing chamber exist in the form of a gas-oil mixture with a lower density, which has an adverse effect on the recycling and recovery of the lubricating oil.

[0003] The problems existing in the existing bearing chamber are that the bearing chamber has a large volume, and the gas-oil mixture rotates in a large space, which is not conducive to oil return. And during the oil return process of the bearing chamber, if the high-speed air flow enters the oil return chamber, it will cause the lubricating oil in the oil return chamber to be blown out of the oil chamber, which is not conducive to oil return. Therefore, a high-speed rotor bearing chamber with an oil-gas separation device is needed to solve the problem of low oil return efficiency in the existing bearing chamber. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a high-speed rotor bearing chamber with an oil-gas separation device. The bearing chamber is divided into two front and rear oil collecting ring chambers with the bearing and the web of the rear bearing frame of the turbine as the boundary, which reduces the flow space of the gas-oil mixture, accelerates the flow speed of the gas-oil mixture, and is conducive to the oil return of the lubricating oil. It provides an oil-gas separation device located at the outer edge of the bearing chamber, so that the lubricating oil and air are separated from each other, ensuring that the lubricating oil can fully gather and flow to the oil return pipe to be smoothly absorbed, improving the oil return efficiency, and not significantly increasing the weight of the bearing chamber, so as to improve the engine performance without significantly changing the weight of the engine.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A high-speed rotor bearing chamber with an oil-gas separation device, the bearing chamber is the bearing chamber of the low-pressure turbine at the rear of the engine, and the bearing chamber is composed of a bearing, a first graphite sealing device, a second graphite sealing device, an oil-gas separation device and a connection structure. Its structural characteristics are as follows:

[0007] The bearing cavity is bounded by the bearing and the web of the rear bearing frame of the turbine and is divided into two annular cavities, namely the front oil collecting ring cavity and the rear oil collecting ring cavity.

[0008] The oil-gas separation device is located at the outer edge of the bearing cavity and consists of a graphite seal ring mounting seat, an annular cavity oil-gas separator and the rear bearing frame of the turbine.

[0009] Axial oil holes are opened on the web of the rear bearing frame of the turbine for connecting the front and rear oil collecting ring cavities.

[0010] The bearing housing of the bearing and the web of the rear bearing frame of the turbine are fixed to each other under the action of the axial bolt pressing force.

[0011] The bearing cavity further includes the rear journal of the low-pressure turbine rotor, the oil collecting ring of the rear bearing cavity and the rear baffle.

[0012] The rear journal of the low-pressure turbine rotor is connected to the oil collecting ring of the rear bearing cavity by a pin, and the rear journal of the low-pressure turbine rotor is connected to the graphite sealing runway by a long bolt.

[0013] The graphite seal ring mounting seat is connected to the rear bearing frame of the turbine beside the oil return cavity by bolts and lock washers.

[0014] A first graphite sealing device is adopted between the graphite seal ring mounting seat and the graphite sealing runway, and the oil collecting ring of the rear bearing cavity is pressed against the rear baffle by a second graphite sealing device in the rear bearing cavity.

[0015] Oil return holes are opened on the rear bearing frame of the turbine.

[0016] The annular cavity oil-gas separator is placed between the graphite seal ring mounting seat and the rear bearing frame of the turbine and is axially pressed by the graphite seal ring mounting seat. The annular cavity oil-gas separator is located inside the front oil collecting ring cavity, and its outlet is directly opposite to the oil return hole of the oil return cavity.

[0017] The process of lubricating oil returning in the bearing cavity is as follows: during the high-speed rotation of the rotor, a part of the lubricating oil for lubricating the bearing is radially thrown out from the front side of the bearing and thus enters the front oil collecting ring cavity, and flows radially to the edge position of the front oil collecting ring cavity under the action of centrifugal force; another part of the lubricating oil for lubricating the bearing is radially thrown out from the rear side of the bearing, enters the rear oil collecting ring cavity, and flows to the edge position of the rear oil collecting ring cavity under the action of centrifugal force. Among them, due to the disturbance of the rear journal of the low-pressure rotor in the front oil collecting ring cavity, a part of the oil-gas mixture at the edge position of the front oil collecting ring cavity is separated by the annular cavity oil-gas separator inside the front oil collecting ring cavity, so that the separated lubricating oil enters the oil return cavity through the oil return hole at the front oil collecting ring cavity, and another part converges with the lubricating oil in the rear oil collecting ring cavity through the axial oil hole between the front / rear oil collecting ring cavities and enters the oil return cavity together, and finally is discharged through the oil return pipe.

[0018] Beneficial effects:

[0019] The annular cavity oil-gas separator is an annular body, and its interior is composed of a main flow channel and two branch flow channels. The main flow channel is a gradually shrinking structure. When the engine is working, the rotor rotates at a high speed. When the oil-gas mixture enters the main flow channel of the annular cavity oil-gas separator, it will first be accelerated through the gradually shrinking channel. When passing through the flow channel fork, since the oil droplets in the oil-gas mixture have a relatively large density and high inertia, and the change in the movement direction is relatively small, they will enter the outer flow channel, and then enter the oil return cavity through the oil return cavity oil through-hole at the outlet of the oil-gas separator. Due to the small density, the air micro-masses will change their movement direction under the action of the pressure difference and enter the inner flow channel, thus realizing the separation of oil and gas. Compared with the traditional oil-gas separation device outside the bearing cavity, the engine bearing cavity oil-gas separation device of the present invention can realize the separation of the oil-gas mixture in the front oil collecting ring cavity, and does not significantly increase the weight of the bearing cavity, and increases the oil return efficiency of the lubricating oil through this device. Description of the drawings

[0020] Figure 1 It is a schematic structural diagram of the bearing cavity behind the engine turbine;

[0021] Figure 2 It is an exploded view of the structure of the high-speed rotor bearing cavity oil-gas separation device of the present invention;

[0022] Figure 3 It is a cross-sectional view of the structure of the high-speed rotor bearing cavity oil-gas separation device of the present invention;

[0023] Figure 4 It is a working principle diagram of the annular cavity oil-gas separator.

[0024] Among them: the rear journal of the low-pressure turbine rotor 1, the oil collecting ring of the rear bearing cavity 2, the annular cavity oil-gas separator 3, the bearing 4, the rear bearing force frame of the turbine 5, the first graphite sealing device 6, the rear baffle 7, the graphite seal ring mounting seat 8, the bearing seat 9, the second graphite sealing device 10, the web of the rear bearing force frame of the turbine 11, the graphite sealing runway 12, the pin 13, the long bolt 14, the oil-gas separation device 20, the axial oil hole 21, the oil return pipe 22, the oil return cavity oil through-hole 23, the oil return cavity 24, the front oil collecting ring cavity 31, the rear oil collecting ring cavity 32, the main flow channel a, the branch flow channel b. Specific implementation manners

[0025] Next, the technical solutions implemented in the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. The following embodiments are explanations of the present invention, and the present invention is not limited to the following embodiments.

[0026] Figure 1This is the structural solution used in the bearing cavity at the rear support point of an aeroengine turbine. In this embodiment, the bearing cavity is the bearing cavity at the rear of the low-pressure turbine of the engine. The bearing cavity consists of a bearing 4, a first graphite sealing device 6, a second graphite sealing device 10, an oil-gas separation device 20, and a connection structure.

[0027] The bearing cavity is bounded by the bearing 4 and the web 11 of the rear bearing frame of the turbine and is divided into two annular cavities, namely the front oil collecting annular cavity 31 and the rear oil collecting annular cavity 32. An axial oil hole 21 is opened on the web 11 of the rear bearing frame of the turbine for communicating the front oil collecting annular cavity 31 and the rear oil collecting annular cavity 32.

[0028] The oil-gas separation device 20 is located at the outer edge of the bearing cavity. The oil-gas separation device 20 consists of a graphite seal ring mounting seat 8, an annular cavity oil-gas separator 3, and a rear bearing frame of the turbine 5.

[0029] The bearing housing 9 of the bearing 4 and the web 11 of the rear bearing frame of the turbine are fixed to each other under the action of the axial bolt pressing force.

[0030] The bearing cavity further includes a rear journal of the low-pressure turbine rotor 1, an oil collecting ring 2 for the rear bearing cavity, and a rear baffle 7.

[0031] The rear journal of the low-pressure turbine rotor 1 is connected to the oil collecting ring 2 for the rear bearing cavity through a pin 13, and the rear journal of the low-pressure turbine rotor 1 is connected to the graphite sealing runway 12 through a long bolt 14.

[0032] The graphite seal ring mounting seat 8 is connected to the rear bearing frame of the turbine 5 beside the oil return cavity through bolts and lock washers.

[0033] The annular cavity oil-gas separator 3 is placed between the graphite seal ring mounting seat 8 and the rear bearing frame of the turbine 5 and is axially pressed by the graphite seal ring mounting seat 8.

[0034] A first graphite sealing device 6 is adopted between the graphite seal ring mounting seat 8 and the graphite sealing runway 12, and a second graphite sealing device 10 is adopted between the oil collecting ring 2 for the rear bearing cavity and the rear baffle 7.

[0035] The volume of the engine bearing cavity is relatively large, and the oil-gas mixture rotates in a large space, which is not conducive to oil return. Considering the high-speed agitation of the non-smooth wall surfaces such as bolt heads and bearing cages on the fluid domain, it is difficult for the lubricating oil in the bearing cavity to maintain a pure fluid state, but exists in the form of an oil-gas mixture with a lower density, thus having an adverse impact on the recycling and recovery of the lubricating oil. Therefore, in this embodiment, the bearing cavity is bounded by the bearing 4 and the web 11 of the rear bearing frame of the turbine and is divided into the front oil collecting annular cavity 31 and the rear oil collecting annular cavity 32, reducing the flow space of the oil-gas mixture, accelerating the flow rate of the oil-gas mixture, and being conducive to oil return.

[0036] The oil-gas separation device 20 separates lubricating oil and air from each other, ensuring that the lubricating oil can fully accumulate and flow to the oil return pipe, so as to be smoothly absorbed, improving the oil return efficiency.

[0037] Figure 2 This is an exploded view of the structure of the oil-gas separation device of the present invention. The oil-gas separation device 20 is composed of a graphite seal ring mounting seat 8, an annular cavity oil-gas separator 3, and a turbine rear bearing frame 5. The annular cavity oil-gas separator 3 is placed between the graphite seal ring mounting seat 8 and the turbine rear bearing frame 5 and is axially pressed by the graphite seal ring mounting seat 8. The annular cavity oil-gas separator 3 is located inside the front oil collecting ring cavity 31, and its outlet position is directly opposite to the oil passage hole 23 of the oil return cavity.

[0038] Figure 3 This is a sectional view of the structure of the oil-gas separation device of the present invention. The annular cavity oil-gas separator 3 is an arc-shaped body, and its interior is composed of a main flow channel a and two branch flow channels b. The main flow channel a is a gradually shrinking structure. The outlet position of the annular cavity oil-gas separator 3 is directly opposite to the oil passage hole 23 of the oil return cavity. The lubricating oil accumulates in the oil return cavity 24 through the oil passage hole 23 of the oil return cavity, and the lower part of the oil return cavity is connected to the oil return pipe 22.

[0039] During the process of the lubricating oil returning to the bearing cavity, during the high-speed rotation of the rotor, a part of the lubricating oil used to lubricate the bearing 4 is radially thrown out from the front side of the bearing and thus enters the front oil collecting ring cavity 31, and flows radially to the edge position of the front oil collecting ring cavity 31 under the action of centrifugal force; another part of the lubricating oil used to lubricate the bearing is radially thrown out from the rear side of the bearing and enters the rear oil collecting ring cavity 32, and flows to the edge position of the rear oil collecting ring cavity 32 under the action of centrifugal force. Among them, due to the disturbance of the rear journal 1 of the low-pressure turbine rotor to the front oil collecting ring cavity, a part of the oil-gas mixture at the edge position of the front oil collecting ring cavity is separated into oil and gas through the annular cavity oil-gas separator 3 inside the front oil collecting ring cavity, so that the separated lubricating oil enters the oil return cavity 24 through the oil passage hole 23 of the oil return cavity at the front oil collecting ring cavity, and another part converges with the lubricating oil in the rear oil collecting ring cavity through the axial oil hole 21 between the front / rear oil collecting ring cavities and enters the oil return cavity 24 together, and finally is discharged through the oil return pipe 22.

[0040] The oil-gas separation process in the oil-gas separator is as Figure 4 shown. When the oil-gas mixture enters the main flow channel of the annular cavity oil-gas separator 3, it will be first accelerated through the gradually shrinking channel. When passing through the flow channel fork, since the oil droplets in the oil-gas mixture have a relatively large density and high inertia and a relatively small change in the movement direction, they will enter the outer flow channel, and then enter the oil return cavity 24 through the oil passage hole 23 at the outlet of the oil-gas separator 3. And the air micro-masses will change the movement direction under the action of the pressure difference and enter the inner flow channel, thus realizing the oil-gas separation.

[0041] In order to ensure that the lubricating oil in the bearing cavity does not spill outwards, a sealing device needs to be introduced at an appropriate position. In this embodiment, in the bearing cavity of the bearing 4, a first graphite sealing device 6 is adopted between the graphite sealing ring mounting seat 8 and the graphite sealing runway 12, and a second graphite sealing device 10 is adopted between the oil collecting ring 2 of the rear bearing cavity and the rear baffle 7. By utilizing the reliable sealing performance of the graphite sealing device under high temperature, high pressure, and high rotational speed conditions, the lubricating oil in the bearing cavity is not easily leaked outwards, thereby improving the service life and reliability of the engine.

[0042] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-speed rotor bearing chamber with an oil-gas separation device, characterized in that the bearing chamber consists of a bearing, a first graphite sealing device, a second graphite sealing device, an oil-gas separation device and a connecting structure; the bearing chamber is divided into a front oil collecting ring chamber and a rear oil collecting ring chamber, and the oil-gas separation device is located at the outer edge of the bearing chamber; the oil-gas separation device consists of a graphite seal ring mounting seat, an annular cavity oil-gas separator and a turbine rear bearing frame; the bearing chamber is divided into two oil collecting ring chambers, front and rear, with the bearing and the turbine rear bearing frame web as the boundary; during the high-speed rotation of the rotor, a part of the lubricating oil for lubricating the bearing is radially ejected from the front side of the bearing and thus enters the front oil collecting ring chamber, and flows radially to the edge position of the front oil collecting ring chamber under the action of centrifugal force; another part of the lubricating oil for lubricating the bearing is radially ejected from the rear side of the bearing, enters the rear oil collecting ring chamber, and flows to the edge position of the rear oil collecting ring chamber under the action of centrifugal force; among them, due to the disturbance of the rear journal of the low-pressure rotor in the front oil collecting ring chamber, a part of the oil-gas mixture at the edge position of the front oil collecting ring chamber is separated by the annular cavity oil-gas separator inside the front oil collecting ring chamber, so that the separated lubricating oil enters the oil return chamber through the oil return chamber oil hole at the front oil collecting ring chamber, and another part converges with the lubricating oil in the rear oil collecting ring chamber through the axial oil hole between the front / rear oil collecting ring chambers and enters the oil return chamber together, and finally is discharged through the oil return pipe; when the oil-gas mixture enters the main flow channel of the annular cavity oil-gas separator, it will be accelerated first through the tapered channel, and when passing through the flow channel fork, it will enter the outer flow channel, and then enter the oil return chamber through the oil return chamber oil hole at the outlet of the oil-gas separator and enter the inner flow channel, thus realizing oil-gas separation.

2. The high-speed rotor bearing chamber with an oil-gas separation device according to claim 1, characterized in that the bearing seat of the bearing and the turbine rear bearing frame web are fixed to each other under the action of the axial bolt pressing force.

3. A high-speed rotor bearing chamber with an oil-gas separation device according to claim 1, characterized in that, It also includes a rear journal of the low-pressure turbine rotor, an oil collecting ring for the rear bearing chamber and a rear baffle.

4. A high-speed rotor bearing chamber with an oil-gas separation device according to claim 3, characterized in that, the rear journal of the low-pressure turbine rotor is connected to the oil collecting ring for the rear bearing chamber by a pin.

5. A high-speed rotor bearing chamber with an oil-gas separation device according to claim 4, characterized in that, the oil collecting ring for the rear bearing chamber is pressed together with the rear baffle through the second graphite sealing device in the rear bearing chamber.

6. The high-speed rotor bearing chamber with an oil-gas separation device according to claim 1, characterized in that, the graphite seal ring mounting seat is connected to the turbine rear bearing frame beside the oil return chamber by bolts and lock washers.

7. The high-speed rotor bearing chamber with an oil-gas separation device according to claim 6, characterized in that, the annular cavity oil-gas separator is placed between the graphite seal ring mounting seat and the turbine rear bearing frame and is axially pressed by the graphite seal ring mounting seat. The annular cavity oil-gas separator is located inside the front oil collecting ring chamber, and its outlet position is directly opposite to the oil return chamber oil hole.

8. A high-speed rotor bearing chamber with an oil-gas separation device according to claim 7, characterized in that, The lower part of the oil return chamber is connected to the oil return pipe.

9. A high-speed rotor bearing chamber with an oil-gas separation device according to claim 3, characterized in that, the rear journal of the low-pressure turbine rotor is connected to the graphite sealing runway by long bolts.

10. A high-speed rotor bearing chamber with an oil-gas separation device according to claim 9, characterized in that, A first graphite sealing device is adopted between the graphite seal ring mounting seat and the graphite sealing runway.

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