JPS61142328A - Lubrication mechanism in exhaust turbine supercharger - Google Patents

Abstract

PURPOSE:To separate seal air from lubrication oil to reduce the discharge of oil mist from a lubrication oil discharge passage, by providing seal air relief passages between an exhaust chamber in a bearing casing and a labyrinth section. CONSTITUTION:Seal air relief passages 25, 26, 27 are provided between oil labyrinths 20, 30 and a bearing casing 70. With this arrangement, seal air spaces 5, 55 flows into a passage 75 provided outside of the bearing casing 70 through the gaps between the oil labyrinths 20, 30 and a rotor shaft 90 and a turbine 10 and the relief passages 25, 26 provided at arbitrary positions. Further, seal air in the passage 75 is discharged to the outside of the bearing casing 70 through a pipe line 80 attached to the bearing casing 70. Accordingly, the amount of seal air flowing into the bearing casing 70 is reduced, and seal air may be separated from lubrication oil within the bearing casing 70.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a lubrication mechanism for an exhaust turbine supercharger.

[Conventional technology]

An overview and drawbacks of the conventional example will be described with reference to FIG. In the exhaust turbine supercharger, since the rotor shaft 90 rotates at high speed, lubricating oil is supplied to the bearings 40 and 45. Therefore, the inside of the bearing casing 70 is filled with lubricating oil. Therefore, lubricating oil leaks into the space 5 on the back of the impeller 10 and the space 55 between the rotor shaft 90 and the bearing casing 70.
An oil labyrinth 20.30 is provided to prevent oil leakage. Furthermore, in order to prevent oil leakage, a space 55 on the turbine side is provided.
Since a portion of the compressed air discharged from the impeller 10 is guided as seal air through the passages 50 and 60, the pressure in the space 55 is higher than that inside the bearing casing 70, further preventing oil leakage. K further prevents oil leakage into the space 5 on the back side of the blower side impeller 10.
The impeller 1 enters the space 5 from the gap 15 between the bearing casing 70 and the bearing casing 70.
Since a part of the compressed air discharged from the bearing casing 70 flows in, the pressure in the space 5 becomes higher than the inside of the bearing casing 70 and acts as sealing air, thereby preventing oil leakage. However, the seal air in the spaces 5 and 55 flows into the bearing casing 70 from the gap between the rotor shaft 90 and the oil labyrinth 30 and the gap between the impeller 10 and the oil labyrinth 20 due to the pressure difference. The lubricating oil is discharged from the lubricating oil outlet passage 85 together. As a result, a large amount of lubricant mist was generated.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust turbine supercharger in which seal air and lubricating oil (Lad) are separated in order to eliminate the drawbacks of the conventional device and reduce lubricating oil (L4d) mist.

[Means for solving problems]

In order to reduce the flow of seal air into the bearing casing 70, seal air relief passages 25, 65, 75 are provided in the oil labyrinths 20, 30 and the bearing casing 70 to separate the seal air and lubricating oil (Lρ). The feature is that the amount of oil discharged from the lubricating oil discharge passage 85 is reduced.

〔Example〕

An embodiment of the present invention will be described above with reference to FIG.

Here, the same or equivalent components as those of the conventional device will be described using the same reference numerals.

Since the turbocharger's a-evening shaft 90 is rotating at high speed, its bearings 40 and 45 are supplied with lubricating oil. Therefore, the inside of the bearing casing 70 is filled with lubricating oil. Therefore, oil labyrinths 20 and 30 are provided to prevent lubricating oil from leaking into the back space 5 of the impeller 10 and the space 55 between the rotor shaft and the bearing casing 70. Furthermore, in order to prevent oil leakage, high-pressure air from the blower 10 is flowed into the turbine-side space 55, and a portion of the high-pressure air discharged from the impeller flows into the space 5 on the back of the blower-side impeller 10. The pressure becomes higher from the inside of the bearing casing 70 and acts as seal air to prevent oil leakage. However, seal air from spaces 5 and 550 instead flows into the bearing casing gate 0 due to the pressure difference and is discharged from the lubricating oil discharge passage 85 together with the discharged oil from the bearings 40 and 45. As a result, a large amount of lubricant mist was generated.

In the present invention, seal air escape passages 25, 65 and 75 are provided in the oil labyrinths 20 and 30 and the bearing casing 70 in order to reduce the seal air flowing into the bearing casing 70.

The route of seal air in the present invention will be explained.

The seal air in spaces 5 and 55 flows through the oil labyrinth 20.
, 30, the rotor shaft 90, and the impeller 1o, and the relief passage 25 provided at an arbitrary position in the oil labyrinth 20.30.
．． 65 and into a passage 75 provided on the outside of the bearing casing 70.

The seal air in the passage 75 passes through a pipe 80 attached to the bearing casing 70 and is discharged to the outside of the bearing casing 70 . Therefore, the amount of seal air flowing into the bearing casing 70 is reduced, and the lubricating oil and seal air inside the bearing casing 70 can be separated.

〔Effect of the invention〕

As described above, the lubrication mechanism of the exhaust turbine supercharger according to the present invention provides a seal air relief passage in the oil labyrinth and the bearing casing to separate the seal air and lubricating oil, so that oil mist from the lubricating oil discharge passage is prevented. emissions can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a main structural diagram of an embodiment according to the present invention, and FIG. 2 is a main structural diagram of a conventional device. 20.30...oil labyrinth, 25,65.75...
・Seal air relief passage, 70...Bearing casing.

Claims (1)

[Claims] Exhaust chamber of bearing casing (70) and oil labyrinth (20)
) and (30), there is a seal air relief passage (25) between the
, (65) and (75).