JPH09189232A - Lubricating oil seal device of exhaust gas turbine supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a supercharger for a long period stably by arranging a blow-off hole communicated with an outside on the way of a turbine side oil labyrinth for sealing lubricating oil of the turbine side of an exhaust gas turbine supercharger, and blowing-off seal air of the turbine side from the blow-off hole outward. SOLUTION: The rotary part of an exhaust gas turbine supercharger consists of a compressor impeller, a turbine moving blade, a turbine disk 3, and a rotor shaft 4, and a compressor side oil labyrinth and a turbine side oil labyrinth 7 are installed on both right and left sides of the rotor shaft 4. In this case, a blow-off hole 11 communicated with an outside penetrating a bearing base 5 is arranged in the position on the way where labyrinth fins of several stages are passed, in the turbine side oil labyrinth 7. Pressure of the bearing base 5 is reduced to the same level as an atmosphere so as to prevent mist in the bearing base 5 from invading to a compressor side striding over the compressor side oil labyrinth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for sealing a turbine side lubricating oil of an exhaust gas turbine supercharger.

[0002]

2. Description of the Related Art FIG. 2 shows a state of installation of a supercharger incorporated in a main engine such as a diesel engine.

The air compressed by the compressor Cp enters the main engine E through the cooler C and contributes to combustion.
The combustion exhaust gas discharged from the main engine E enters the turbine T, is given a rotational force, and is then discharged to the atmosphere. Here, the supercharger SC connects the compressor C and the turbine T to the rotor shaft S.
It is connected and rotated integrally.

FIG. 3 shows a seal structure for preventing the lubricating oil in the bearing stand 5 from leaking out of the bearing stand 5 in the conventional supercharger SC.

A part of the air compressed through the compressor impeller 1 enters the compressor back surface 9 from the compressor outlet 1a, and enters the bearing stand 5 through the oil labyrinth 6 on the compressor side.

On the other hand, the combustion exhaust gas discharged from the main engine E enters leftward toward the turbine rotor blades 2 planted in the turbine disk 3, so that a leftward force acts on the rotor 4. .

In order to reduce the leftward force, a part of the high pressure air in the vortex chamber 8 is guided to the turbine rear surface 13 through the passage 10 and the rightward force is applied to the rotor 4 against the leftward force. . After that, this high-pressure air on the turbine rear surface 13 passes through the oil labyrinth 7 on the turbine side and enters the bearing stand 5.

In this way, the lubricating air in the bearing stand 5 is transmitted along the rotor shaft by the sealing air from the oil labyrinth 6 on the compressor side and the sealing air from the oil labyrinth 7 on the turbine side. Bearing base 5 beyond 7
It prevents it from leaking out.

The air in the bearing base 5 is the mist extraction pipe 1
2 is released to the atmosphere, and the lubricating oil is discharged from the lubricating oil return pipe 14 to the outside.

[0010]

When the high-pressure air in the bearing stand 5 becomes bubbles and mixes with the oil in the lubricating oil return pipe 14,
If the lubricating oil becomes difficult to be discharged, and if the mist cools and the lubricating oil is generated in the middle of the mist extraction pipe 12, the air in the bearing stand 5 becomes difficult to be discharged. On the other hand, in the bearing stand 5, Since the high pressure air in the vortex chamber 8 is supplied through the oil labyrinth 7 on the turbine side, the pressure in the bearing stand 5 becomes high.

Since the pressure on the compressor rear surface 9 is not as high as the thrust balance and sealing air on the turbine rear surface 13, the high pressure air containing the lubricating oil mist in the bearing stand 5 causes the oil labyrinth 6 on the compressor side. There is a problem that the oil may flow back to the back surface 9 of the compressor, the lubricating oil may be accumulated in the lower part of the vortex chamber 8, and the lubricating oil may leak to the outside of the supercharger.

It is an object of the present invention to prevent the occurrence of such troubles, reliably perform sealing of lubricating oil, and provide a turbocharger which can be stably operated for a long period of time. To do.

[0013]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and blows air to the outside in the middle of a turbine-side oil labyrinth for sealing lubricating oil on the turbine side of an exhaust gas turbine supercharger. We provide a lubricating oil seal device for an exhaust gas turbine supercharger that has a hole to blow the sealing air on the turbine side to the outside from the blowing hole, and to open the blowing hole that leads to the outside from the middle of the oil labyrinth on the turbine side. By providing the thrust balance on the turbine side and the pressure of the air for sealing sufficiently high, the pressure inside the bearing stand that requires a lubricating oil seal is kept low, and the air in the bearing containing lubricating oil mist is compressed. It prevents the oil from flowing back over the oil labyrinth on the side to the back of the compressor.

That is, the high-pressure air for thrust balance and sealing on the turbine side is discharged to the outside of the bearing stand or the like from a position halfway through the oil labyrinth fin, through the oil labyrinth and the air blow hole. As a result, most of the sealing air that passes through the oil labyrinth from the turbine side is discharged to the outside while the thrust balance and the pressure of the sealing air are kept high. The pressure is kept low. As a result, the air on the back side of the compressor easily flows into the bearing stand and the like through the oil labyrinth on the compressor side, so that the lubricating oil is prevented from leaking to the compressor side.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIG. Since the basic structure of the exhaust gas turbine supercharger is the same as that shown in FIG. 3 as a conventional one, the constituent members and reference numerals of FIG. 3 are referred to when necessary for explanation. The same parts as those in FIG. 1 are designated by the same reference numerals, and the overlapping description will be omitted.

The rotating part of the exhaust gas turbine supercharger includes a compressor impeller 1, a turbine rotor blade 2 and the same turbine rotor blade 2.
Turbine disk 3 with planted
And a rotor shaft 4 integrated with the above.

A compressor side oil labyrinth 6 and a turbine side oil labyrinth 7 are attached to the left and right sides of the rotor shaft 4 in order to seal the lubricating oil in the bearing base 5.

The turbine-side oil labyrinth 7 is provided with a bearing stand 5 at a position midway through several labyrinth fins.
A ventilation hole 11 is provided which penetrates through and communicates with the outside.

Since this embodiment is constructed in this way, the turbine rear surface 1 is now passed from the vortex chamber 8 through the passage 10.
The high pressure air led to 3 is the oil labyrinth 7 on the turbine side.
At a position where the labyrinth fin has been passed through several stages, a part of the labyrinth fin is blown into the atmosphere through the vent hole 11, and the decompressed remaining air passes through the remaining labyrinth fin of the oil labyrinth 7 and the bearing. Enter the table 5 and seal the lubricating oil.

By releasing the air from the air outlet 11 in this way, the pressure of the bearing stand 5 is lowered to a level equivalent to the atmospheric pressure, and the mist in the bearing stand 5 passes over the oil labyrinth 6 on the compressor side and the compressor. Never invades,
Lubricant oil sealing of the bearing base 5 is reliably performed by the oil labyrinths 6 and 7 on the compressor side and the turbine side, respectively, and the exhaust gas turbine supercharger can operate stably for a long period of time.

Although the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to such embodiments.
It goes without saying that various modifications may be made to the specific structure within the scope of the present invention.

[0022]

As described above, according to the present invention, the pressure inside the bearing stand for lubricating oil sealing is kept low by adding a simple structure in which a ventilation hole communicating from the middle of the oil labyrinth on the turbine side to the outside is provided. Since the lubricating oil will not leak to the compressor side and further to the outside of the turbocharger, the turbocharger can be operated safely, reliably and stably for a long period of time. is there.

[Brief description of the drawings]

FIG. 1 is a structural diagram of a turbine-side oil labyrinth of an exhaust gas turbine supercharger according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of installation of a general exhaust gas turbine supercharger incorporated in a main engine such as a diesel engine.

FIG. 3 is a structural diagram showing a seal configuration of lubricating oil in a bearing stand of a conventional exhaust gas turbine supercharger.

[Explanation of symbols]

 1 Compressor Impeller 2 Turbine Blade 3 Turbine Disk 4 Rotor Shaft 5 Bearing Stand 6 Compressor Oil Labyrinth 7 Turbine Oil Labyrinth 8 Swirl Chamber 9 Compressor Back 10 Air Passage 11 Air Blow Hole 13 Turbine Back

Claims (1)

[Claims] 1. An air vent that communicates with the outside is provided in the middle of a turbine side oil labyrinth that seals a turbine side lubricating oil of an exhaust gas turbine supercharger, and the turbine side seal air is emitted to the outside through the air vent. Lubricating oil seal device for exhaust gas turbine supercharger characterized by being blown.