JP2002364376A - Exhaust-driven supercharger for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To integrate the space with the exhaust-driven supercharger at low cost by preparing a large space capable of ensuring sufficient separation of oil from a lubricating oil circuit and air reaching a bearing housing from a compressor and a turbine by way of a rotor shaft seal device of an exhaust- driven supercharger, in an exhaust-driven supercharger for an internal combustion engine comprising the compressor 2, the bearing housing 4 and the turbine 3, wherein a compressor impeller 5 and a turbine runner 6 are disposed on a common rotor shaft 7 and an air extraction system is annexed to separate oil from the lubricating oil circuit and air intruding in the bearing housing from the compressor and the turbine. SOLUTION: As the air extraction system, an annular space 10 of an enough volume to separate oil and air completely is arranged in the bearing housing 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust-driven supercharger for an internal combustion engine according to the preamble of claim 1.

[0002]

2. Description of the Related Art For example, European Patent Application Publication No. 079
No. 4319 describes a typical exhaust-driven supercharger of an internal combustion engine, comprising as basic components a compressor, a bearing housing and a turbine. The compressor impeller and turbine runner are located on a common rotor shaft, and the rotor shaft is hydraulically supported within a bearing housing or within a bearing body between the compressor impeller and turbine runner. The hydraulic bearing or bearing is connected to the engine lubricating oil circuit, but also to an external oil tank.

[0003] In the case of such an exhaust-driven supercharger in which the rotor shaft is supported by the hydraulic pressure between the compressor impeller and the turbine runner, the problem or necessity of always sealing the bearing chamber to the compressor side or the turbine side is required. Nature occurs. As is known, the sealing is performed by a non-contact packing such as a labyrinth packing or by a contact packing such as a piston ring. This kind of hermetic approach cannot avoid a certain amount of volume leakage flow.

[0004] In most cases, sealed air is supplied to the turbine side in order to prevent exhaust gas from entering the bearing housing.

[0005] In this way, air enters the bearing chamber or the oil chamber of the bearing housing, and this air mixes with the oil splashed by the bearings to form an oil mist. Usually, since the internal space of the bearing housing is small, the mist does not adhere to the inner wall of the bearing housing, and flows out of the exhaust driven turbocharger through a normal oil outlet of the bearing housing.

In order to prevent the amount of retained air from increasing the driving room pressure of the internal combustion engine to be supplied, an air venting process must be taken at the oil outlet outside the exhaust drive supercharger. This is because, as is well known, good separation between oil and air can only be performed with a large volume. Today, in the case of small venting chambers made possible by exhaust-driven superchargers, the exhaust air from the oil outlet generally still contains oil and pollutes the atmosphere.

For example, German Patent Application Publication No. 195234
The exhaust drive supercharger described in the specification of Japanese Patent No. 80 is connected to an engine lubricating oil circuit, and the engine lubricating oil circuit is provided with an external air vent system. The turbocharger is connected downstream of the engine lubricating oil circuit in the engine crankcase and has an oil drain pipe, which leads to the measuring device. As a result, the amount of exhaust gas that reaches the oil circuit from the compressor and the turbine through the rotor shaft sealing device of the exhaust drive supercharger is measured.

The measuring device includes a so-called sedation tank. Further, a bypass valve is provided between the oil discharge pipe of the exhaust-driven supercharger and the highest point of the oil discharge pipe of the calming tank.
Thus, the oil flowing out of the exhaust drive supercharger is directly guided to the oil tank.

[0009] These are all expensive means and require additional space.

[0010]

SUMMARY OF THE INVENTION The object of the invention is to provide an exhaust-driven supercharger of the type described at the outset through which oil from the lubricating oil circuit passes through the rotor shaft sealing device of the exhaust-driven supercharger. To provide a large enough space to sufficiently separate the air reaching the bearing housing from the compressor and turbine and thus into the oil circuit, and to inexpensively integrate this into the exhaust drive turbocharger. is there.

[0011]

This object is achieved according to the invention by means of the first aspect.

As the air vent system, an annular space having a volume sufficient to sufficiently separate oil and air is provided inside the bearing housing of the exhaust-driven supercharger, so that the bearing housing particularly accommodates the hydraulic bearing of the rotor shaft. An annular space for venting the lubricating oil, the annular space at least partially coaxially surrounding the oil chamber, the annular space being connected on the one hand by an overflow port to an external oil bath and via an oil outlet The bearing housing is connected to the drive chamber of the engine, while being connected to the oil chamber via an oil passage, and the bearing housing is related to the volume of the annular space integrated therein, filling the useful structural space between the compressor and the turbine. As a result, an air vent system integrated with the bearing housing is provided for the bearing of the rotor shaft. In this case, a space large enough to separate oil and air from oil mist generated in the bearing housing can be prepared. Accordingly, the oil mist can be used as an auxiliary bearing coolant at the same time.

That is, in the present invention, a useful structural space between the turbine and the compressor is formed as large as possible in the bearing housing, so that an annular space for bleeding air from the lubricating oil, that is, an air bleeding system is integrally formed in the bearing housing. Use best to incorporate.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows an advantageous embodiment of the exhaust-driven supercharger of an internal combustion engine according to the invention, which has a sufficient annular volume in the bearing housing to completely separate oil and air.

The exhaust-driven supercharger 1 includes a compressor 2, a turbine 3, and a bearing housing 4 disposed therebetween.

Although not shown here in principle, and thus not shown here, a spiral guide passage surrounding the radial impeller 5 of the compressor 2 is connected to the compressor side of the bearing housing 4 and is connected to the turbine side. , (Here axial flow) are connected to a guide passage surrounding the turbine runner 6.

The compressor impeller 5 and the turbine runner 6
It is on a common rotor shaft 7. The shaft 7 is supported in the bearing housing 4 by a hydraulic radial bearing or bush as is known.

The hydraulic bearing of the rotor shaft 7 is surrounded by a cylindrical bearing body 8. The cylindrical bearing body 8 is incorporated in a state where an oil chamber 9 is formed in the bearing housing 4.

Further, an air vent system in the form of an annular space 10 having a volume sufficient to separate oil and air is provided inside the bearing housing 4.

The annular space 10 is partially coaxially arranged around the oil chamber 9. The annular space 10, on the one hand, is connected to an external oil tank via an overflow port 11 and to a drive room of the engine via an oil outlet 12,
On the other hand, it is connected to the oil chamber 9 by an oil passage. The air that has entered the oil chamber 9 through the shaft sealing device of the rotor shaft and that has become oil mist by being mixed with the oil present therein reaches the annular space 10 via the above-described connection circuit, where the oil is returned again. Separated from Then, only the oil is discharged from the oil outlet 12 of the annular space 10. The oil mist 13 attached to the inner wall of the bearing housing 4 has a cooling function.

The bearing body 8, which is incorporated in the bearing housing 4 in a suitable manner, is, on the one hand, separated from the annular space 10 by the radial bore 20 and the outer circumferential groove 21 of the cylindrical bearing body 8.
An oil passage is formed, on the other hand, via another peripheral groove 22,
An oil passage from the bearing body 8 to the oil chamber 9 is formed,
In addition, the oil chamber 9 has a connection path 23 with the annular space 10 of the bearing housing 4.

Accordingly, the bearing housing 4 is formed so as to fill a useful space between the compressor 2 and the turbine 3 according to the volume of the integrated annular space 10.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an exhaust-driven supercharger according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust drive supercharger 2 Compressor 3 Turbine 4 Bearing housing 5 Compressor impeller 6 Turbine runner 7 Rotor shaft 8 Bearing body 9 Oil chamber 10 Annular space 11 Overflow port 12 Oil outlet 13 Oil mist 20 Radial holes 21, 22 Outer circumference Groove 23 Connection path

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Wolfgang Schmidt Germany 86153 Augsburg Tommstrasse 21 F-term (reference) 3G005 EA04 EA16 FA31 GB41 GB57 GB74 GB82

Claims (3)

[Claims] 1. A compressor, a bearing housing, and a turbine, wherein a compressor impeller and a turbine runner are mounted on a common rotor shaft, and the rotor shaft is hydraulically mounted in the bearing housing between the compressor impeller and the turbine runner. The bearings are supported by hydraulic bearings, the hydraulic bearings being connected to a lubricating oil circuit, which is provided with an air bleed system for separating oil from the circuit from air entering the bearing housing from the compressor and turbine. In an exhaust-driven supercharger for an internal combustion engine, an annular space (10) having a volume sufficient to completely separate oil and air is provided inside a bearing housing (4) as an air vent system. Supercharger. 2. The bearing housing (4) comprises a rotor shaft (7).
An annular space (10) having an oil chamber (9) for accommodating the hydraulic bearing of the present invention, wherein an annular space (10) for bleeding air from the lubricating oil coaxially at least partially surrounds the oil chamber (9),
On the one hand, it is connected to the oil tank via an overflow port (11) and to the drive room of the engine via an oil outlet (12), and on the other hand to the oil chamber (9) via an oil passage (20-23). The bearing housing (4) is connected to fill the useful structural space between the compressor (2) and the turbine (3) in relation to the volume of the annular space (10) integrated therein. The supercharger according to claim 1, characterized in that: 3. The hydraulic bearing of a rotor shaft (7) is surrounded by a cylindrical bearing body (8), the bearing body (8) being incorporated in an oil chamber (9) of a bearing housing (4), while Radial holes (20) and outer circumferential grooves (21) in the cylindrical bearing body (8) allow the bearing body (8) to be removed from the annular space (10).
An oil passage is formed from the bearing body (8) to the oil chamber (9) via another outer circumferential groove (22) on the other hand, and the oil chamber (9) is formed. 3. The turbocharger according to claim 1, further comprising a connection path for connecting the bearing housing with the annular space of the bearing housing. 4.