JP2003293783A - Oil seal device of supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil seal device of a supercharger capable of surely preventing lubricating oil from leaking to the outside of the supercharger in the wide operating range of an engine. <P>SOLUTION: In this supercharger 1, a turbine 12 is rotated by the gas flow of exhaust gas to rotate a compressor 13 installed on a rotating shaft for the turbine so as to compress and feed suction air. Labyrinth fins 26 are fitted to a bearing support 22 positioned around the rotating shaft so that the lubricating oil fed to the bearings 8a, 8b, 9, and 10 of the rotating shaft 11 does not leak to the outside of the supercharger. Fins 28 capable of spattering the lubricating oil leaking along the surface of the rotating shaft to the outside by a centrifugal force by the rotation of the rotating shaft are formed integrally with the outer periphery of a sleeve 16 on the rotating shaft positioned on the inside of the labyrinth fins. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mounted on an engine such as a ship or a private power generator and rotates a turbine by a gas flow of exhaust gas, and the turbine drives a compressor to send compressed intake air to the engine. The present invention relates to an oil seal device for a supercharger to be supplied.

[0002]

2. Description of the Related Art A diesel engine for a ship or a generator (which is also applied to some gas engines) is equipped with a turbocharger as a device for increasing its output. This turbocharger guides exhaust gas from a diesel engine to turbine blades, rotates the turbine with the gas flow, and rotates a compressor installed coaxially with this turbine, compressing intake air and combustion chamber of the engine. To send to. In this way, the turbocharger can send a large amount of combustion air into the combustion chamber, which can be useful for energy saving and high output.

In this turbocharger, a turbine is generally fixed to one end of a rotary shaft and a compressor (impeller) is fixed to the other end of the rotary shaft. The rotary shaft has a thrust bearing and a journal (radial) bearing. It is rotatably supported by the casing. Then, as shown in FIG. 3, the thrust bearing 101 and the journal bearing 10 of the rotary shaft 100.
In order to prevent the lubricating oil supplied from the oil passages 103 and 104 to 2 from leaking to the compressor impeller 105 side (outside the supercharger), conventionally, the bearing support 107 facing the rotation shaft 100 (outer circumference of the sleeve 106) ( The labyrinth fin 108 was provided on the casing side, and the seal air was fed from the compressor impeller 105 side. In FIG. 3, 109 is a thrust collar.

[0004]

However, in the conventional oil seal device as described above, the labyrinth fin 108 has a low seal air pressure when the diesel engine is operated under a low load. Could not be expected to have a sufficient effect, and there was a fear that lubricating oil would leak to the compressor impeller 105 side (outside the supercharger) along the surface of the rotating shaft 100.

The present invention solves such a problem and provides an oil seal device for a supercharger capable of reliably preventing leakage of lubricating oil to the outside of the supercharger in a wide operating region of the engine. The purpose is to provide.

[0006]

An oil seal device for a supercharger according to a first aspect of the present invention for achieving the above object rotates a turbine by a gas flow of exhaust gas, and rotates the same shaft as the turbine. In a supercharger that compresses and feeds intake air by rotating a compressor provided above, in order to prevent the lubricating oil supplied to the bearing of the rotary shaft from leaking out of the supercharger. A labyrinth fin is provided on the opposing casing side, and the lubricating oil transmitted to the rotary shaft side inside the labyrinth fin is transmitted outward by the centrifugal force generated by the rotation of the rotary shaft. It is characterized in that a fin for obtaining is provided.

Further, in the oil seal device for a supercharger according to a second aspect of the present invention, the fins are provided on an outer peripheral portion of a sleeve fitted to the rotary shaft adjacent to the compressor impeller, and the fins are provided. It is characterized in that it forms a labyrinth seal with the fins.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an oil seal device for a supercharger according to the present invention will be described in detail with reference to the drawings based on embodiments.

FIG. 1 is a sectional view of a supercharger according to an embodiment of the present invention, and FIG.

As shown in FIG. 1, in a supercharger 1, a turbine-side casing 3 and an exhaust introduction pipe 4, a compressor-side casing 5 and an intake air introduction pipe 6 are sandwiched by a bolt 7 by sandwiching a bearing stand 2 in a central portion. It is configured by being integrally fastened. A rotary shaft 11 is rotatably supported on the bearing base 2 via thrust bearings 8a and 8b and journal (radial) bearings 9 and 10, and a turbine 12 is fixedly coupled to one end of the rotary shaft 11, while the other is fixed. The compressor 13 is fixed to the end portion. In addition, reference numeral 14 in FIG. 1 denotes a thrust collar fixed to the center of the rotary shaft 11.

The turbine 12 has a large number of blades 12a on its outer peripheral portion, and the exhaust gas from a diesel engine (not shown) is guided to the blades 12a through the exhaust gas introducing pipe 4 and is rotated. The exhaust gas is discharged from the exhaust gas exhaust passage 15 in the turbine side casing 3 to the outside through an exhaust duct and a chimney (not shown). On the other hand, the compressor 13 includes an impeller (impeller) 13a fixed on the rotary shaft 11 adjacent to the sleeve 16.
The rotation of the impeller 13a compresses the air guided from the intake air introducing pipe 6, and the intake air introducing passage 17, the spiral chamber 18, and the intake air feeding passage 19 in the compressor-side casing 5 are used to drive a diesel engine (not shown). It is pumped to the intake system.

The turbine side journal bearing 9 is also provided.
Is supported by a bearing support 20, and this bearing support 20
Is detachably attached to the bearing base 2 with bolts 21. On the other hand, the journal bearing 1 on the compressor side
0 and one thrust bearing 8b are both bearing supports 22
The bearing support 22 is detachably attached to the bearing base 2 with bolts 23. The other thrust bearing 8a is directly attached to the bearing base 2 with a bolt 24. In the thrust bearings 8a and 8b and the journal bearings 9 and 10, lubricating oil passages 25a formed in the bearing base 2 and the bearing supports 20 and 22, respectively,
Lubricating oil is supplied through 25b and 25c.

Also, as shown in FIG. 2, the labyrinth fin 26 is provided on the bearing support 22 as a casing side member facing the rotary shaft so that the lubricating oil does not leak to the compressor side (outside the supercharger). Bolt 2
7, and a slight gap is formed between the tip of the annular fin of the labyrinth fin 26 and the outer circumference of the impeller of the compressor 13. Further, on the outer peripheral portion of the sleeve 16 positioned inside the labyrinth fin 26, the fin 28 that can sway the lubricating oil transmitted on the surface of the rotating shaft outward by the centrifugal force generated by the rotation of the rotating shaft 11.
Are integrally formed.

Further, the fin 28 is formed in an L-shape which extends along the inner peripheral surface of the labyrinth fin 26 in the radial direction of the rotary shaft 11 by a predetermined dimension and is then bent at a right angle to the compressor side. A slight gap between the inner peripheral surface of 26 and the inner peripheral surface of the inner wall 26 forms a labyrinth seal connected to the latter stage of the annular fin.

Therefore, as shown in FIG. 1, when the exhaust gas from the diesel engine is guided to the turbine 12 through the exhaust introduction pipe 4 of the supercharger 1, the turbine 12 is rotated by the gas flow of the exhaust gas. The exhaust gas is discharged from the exhaust gas discharge passage 15. At the same time, the turbine 1
2, the compressor 13 integrally provided coaxially via the rotary shaft 11 rotates, the air is filtered by the filter of the intake air introducing pipe 6 and taken into the intake air introducing passage 17 and swirled by the compressor 13. The air compressed in the chamber 18 is sent into the combustion chamber of the diesel engine through the intake air supply passage 19, so that the diesel engine can have a high output.

At this time, the thrust bearings 8a, 8b and the journal bearings 9, 10 supporting the rotary shaft 11 are provided with lubricating oil passages 25a, 25b, 25c formed in the bearing base 2 and the bearing supports 20, 22, respectively. Lubricating oil is supplied through. When the diesel engine is operating at high speed and under high load, the labyrinth seal portion formed by the labyrinth fins 26 and 28 is supplied with sufficiently high pressure sealing air from the compressor side to the turbine side. In the portion, a sufficient sealing action is obtained, and the lubricating oil supplied to the thrust bearings 8a and 8b and the journal bearings 9 and 10 is prevented from leaking to the compressor side along the surface of the rotary shaft 11. Further, in this embodiment, the labyrinth fin 26 and the fin 28 are provided.
Since the labyrinth seal portion having a large seal width is configured by the above, the sealing property is much higher than that of the labyrinth fin 26 alone.

On the other hand, at the time of idle operation of the diesel engine or at low speed / low load operation, the pressure of the exhaust gas acting on the turbine 12 is low, so that the turbine 12 also becomes low speed and the compressor 13 does not compress the intake air. On the contrary, the suction force from the combustion chamber side of the diesel engine causes a negative pressure state in the swirl chamber 18. This allows
The back side of the compressor 13 is also in a negative pressure state, and since high-pressure sealing air is not sent from the compressor side to the turbine side in the labyrinth seal part described above, the labyrinth seal part cannot obtain a sufficient sealing action. , The thrust bearings 8a, 8b and the journal bearings 9, 10
The lubricating oil supplied to the oil flows along the surface of the rotating shaft 11 and leaks to the compressor side.

However, in this embodiment, the fin 28
The lubricating oil transmitted to the surface of the rotating shaft by the
It is shaken out by the centrifugal force due to the rotation of the above, and is collected through an oil passage (not shown) on the drain side without passing through the above-mentioned labyrinth seal portion, and leakage to the compressor side is avoided in advance.

Further, in this embodiment, since the fins 28 are integrally formed on the outer peripheral portion of the sleeve 16, if the fins 28 are damaged or the like, the entire sleeve 16 can be easily replaced.

The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention, for example, forming the fins 28 separately from the sleeve 16. Absent.

[0021]

As described above in detail, according to the oil seal device for a supercharger according to the invention of claim 1, the turbine is rotated by the gas flow of the exhaust gas, and the turbine is rotated on the same rotary shaft as the turbine. In a supercharger that compresses and supplies intake air by rotating a provided compressor, so that the lubricating oil supplied to the bearing of the rotating shaft does not leak outside the supercharger.
A labyrinth fin is provided on the casing side facing the rotary shaft, and the lubricating oil transmitted to the rotary shaft surface inside the labyrinth fin is transmitted to the rotary shaft side by the centrifugal force generated by the rotation of the rotary shaft. Since the fins that can be swung away are provided, the sealing performance is further improved, and it is possible to reliably prevent the lubricating oil from leaking to the outside of the turbocharger in a wide operating region of the engine.

According to the oil seal device of the supercharger of the second aspect of the present invention, the fins are provided on the outer peripheral portion of the sleeve fitted on the rotary shaft adjacent to the compressor impeller. Since the labyrinth seal is formed between the labyrinth fin and the labyrinth fin, the sealability in the high load operation state of the engine is further improved by increasing the seal width, and
If the fins are damaged, the sleeves can be easily replaced.

[Brief description of drawings]

FIG. 1 is a sectional view of a supercharger according to an embodiment of the present invention.

FIG. 2 is likewise an enlarged cross-sectional view of a main part.

FIG. 3 is a sectional view of a main part of a conventional supercharger.

[Explanation of symbols]

1 supercharger 2 bearing stand 3 Turbine side casing 4 Exhaust gas introduction pipe 5 Compressor side casing 6 Intake air introduction pipe 7 volts 8a, 8b thrust bearing 9,10 Journal bearing 11 rotation axis 12 turbine 13 Compressor 14 Thrust color 15 Exhaust gas exhaust path 16 sleeves 17 Intake air introduction path 18 Swirl chamber 19 Intake air supply passage 20,22 bearing support 21,23,24,27 bolts 25a, 25b, 25c Lubricating oil passage 26 Labyrinth Sphinx 28 fins

Claims (2)

[Claims] 1. A turbocharger for compressing and feeding intake air by rotating a turbine by a gas flow of exhaust gas and rotating a compressor provided on the same rotary shaft as the turbine, wherein In order to prevent the lubricating oil supplied to the bearing of the shaft from leaking to the outside of the supercharger, a labyrinth fin is provided on the casing side facing the rotary shaft, and the rotary shaft is located on the rotary shaft side inside the labyrinth fin. An oil seal device for a supercharger, which is provided with fins that allow the lubricating oil transmitted on the surface to be swung outward by a centrifugal force generated by rotation of the same rotary shaft. 2. The oil seal device for a supercharger according to claim 1, wherein the fins are provided on an outer peripheral portion of a sleeve fitted on the rotating shaft adjacent to the compressor impeller, and the fins are provided. An oil seal device for a supercharger, characterized in that a labyrinth seal is formed between the two.