CH715786A2 - Turbocharger. - Google Patents

Abstract

Turbocharger, with a turbine (2) for expanding a first medium, the turbine (2) having a turbine housing and a turbine rotor (5), with a compressor for compressing a second medium using in the turbine (2) when the first medium obtained energy, wherein the compressor has a compressor housing and a compressor rotor coupled to the turbine rotor (5) via a shaft (8), with a bearing housing (9) arranged between the turbine housing and the compressor housing, in which the shaft (8) extends a bearing (18) facing the turbine (2) is mounted, with a cover plate (22) which is located on a side of a bearing ring facing the turbine (2) or a bearing bush (19) of the bearing (18) facing the turbine (2) ) connects to the bearing ring or the bearing bush (19). In the end disk (22), on an axial surface (23) facing the bearing ring or the bearing bushing (19) of the bearing (18) facing the turbine (2), there is a turbulence chamber (24) open in the direction of the bearing ring or the bearing bushing (19). introduced, the oil, which exits from a lubricating gap (20) of the bearing (18), catches and drains.

Description

The invention relates to a turbocharger.

The basic structure of a turbocharger is known to the person skilled in the art addressed here. A turbocharger has a turbine in which a first medium is expanded. Furthermore, a turbocharger has a compressor in which a second medium is compressed using the energy obtained in the turbine when the first medium is expanded. The turbine of the turbocharger has a turbine housing and a turbine rotor. The compressor of the turbocharger has a compressor housing and a compressor rotor. A bearing housing is positioned between the turbine housing of the turbine and the compressor housing of the compressor, the bearing housing being connected on the one hand to the turbine housing and on the other hand to the compressor housing. A shaft via which the turbine rotor is coupled to the compressor rotor is mounted in the bearing housing.

From DE 10 2010 038 527 A1 a turbocharger with a compressor, a turbine and a bearing housing is known. A shaft via which the turbine rotor is coupled to the compressor rotor is mounted in the bearing housing, specifically via a plurality of slide bearings. A plain bearing, which is used to support the shaft in the bearing housing, faces the turbine. Another plain bearing, which is used to support the shaft in the bearing housing, faces the compressor. The bearing facing the turbine is followed by a cover plate which, when the plain bearing has a floating bearing ring or a floating bearing bush, limits the axial displacement of the bearing ring or the bearing bush in the direction of the turbine, and which, when the Bearing bush or the bearing ring is fixed, is used to hold the bearing bush or the bearing ring.

An essential requirement with regard to the operational safety of a turbocharger is the oil tightness of the bearing of the shaft, in particular towards the turbine wheel of the turbine. On the hot turbine side in particular, there is a risk that oil escaping from the bearing housing could ignite. For this reason, shaft seals for mounting the shaft in the bearing housing are essential components for the operational safety of turbochargers.

[0005] There is therefore a need for a turbocharger in which, with simple means, an oil-tightness for the bearing of the shaft in the bearing housing can be provided in particular adjacent to the turbine, safely and reliably. Proceeding from this, the present invention is based on the object of creating a new type of turbocharger.

[0006] This object is achieved by a turbocharger according to claim 1. According to the invention, a turbulence chamber, which is open in the direction of the bearing ring or the bearing bush and which catches and diverts oil that emerges from a lubrication gap in the bearing, is introduced into the end disk on an axial surface facing the bearing facing the turbine. According to the invention, it is proposed that the cover plate, which adjoins the bearing ring or the bearing bush of the bearing of the shaft facing the turbine, has a turbulence chamber that is open in the direction of the bearing ring or the bearing bush. Oil that emerges from the lubrication gap of the bearing can enter the turbulence chamber that is open in the direction of the bearing ring or the bearing bush, where it is collected and calmed. The turbulence chamber diverts the oil that has been collected and calmed off, in the direction of an oil drain in the area of the bearing housing. In this way, oil-tightness can be ensured for the bearing of the shaft in the bearing housing, in particular adjacent to the turbine. The operational reliability of the turbocharger can thus be increased with simple means.

According to a further development of the invention, in the direction of the bearing ring or the bearing bushing, the turbulence space of the end disk is limited on a side facing away from the bearing ring or the bearing bushing by a closed axial wall and on a radially outer side by a closed radial wall. The turbulence chamber of the cover disk, which is open in the direction of the bearing ring or the bearing bush, is delimited on a radially inner side facing the shaft by a web which, starting from the axial wall, opens the turbulence chamber on the side facing away from the bearing ring or the bearing bush is limited, extends in the axial direction to the axial surface facing the bearing ring or the bearing bush and ends at a distance in front of this axial surface. Such a contouring of the turbulence space of the cover disk, which is open in the direction of the bearing ring or the bearing bush, is particularly preferred in order to reliably catch and calm oil emerging from the lubricating gap of the bearing.

The open turbulence space is preferably contoured such that an extension of a bevel of the bearing ring or the bearing bush facing the turbulence space intersects the closed axial wall. These details also serve to safely collect and calm the oil that escapes from the lubrication gap of the bearing.

The web, which delimits the turbulence space radially on the inside, defines a sealing gap to the shaft, the axial length of which is preferably between 0.1 times and 0.7 times the axial thickness of the cover plate and / or its radial width, preferably between is twice and 20 times the radial bearing play between the bearing ring or the bearing bush and the shaft. These details of the closing disk, namely of the web delimiting the swirl space in sections radially on the inside, are advantageous in order to reliably catch the oil which leaves the lubrication gap.

Preferred developments of the invention emerge from the subclaims and the following description. Embodiments of the invention are explained in more detail with reference to the drawing, without being restricted thereto. It shows: <tb> Fig. 1 <SEP> a cross section through a turbocharger, <tb> Fig. 2 <SEP> a detail of a turbocharger according to the invention, <tb> Fig. 3 <SEP> a detail of FIG. 2, and <tb> Fig. 4 <SEP> a further detail of a turbocharger according to the invention.

Fig. 1 shows the basic structure of a turbocharger 1. A turbocharger 1 has a turbine 2 for the expansion of a first medium, in particular for the expansion of exhaust gas from an internal combustion engine. Furthermore, a turbocharger 1 has a compressor 3 for compressing a second medium, in particular charge air, specifically using the energy obtained in the turbine 2 when the first medium is expanded.

The turbine 2 has a turbine housing 4 and a turbine rotor 5. The compressor 3 has a compressor housing 6 and a compressor rotor 7. The compressor rotor 7 is coupled to the turbine rotor 5 via a shaft 8 which is supported in a bearing housing 9 is, wherein the bearing housing 9 is positioned between the turbine housing 4 and the compressor housing 5 and is connected to both the turbine housing 4 and the compressor housing 5.

The turbine housing 4 of the turbine 2 comprises an inflow housing 11 and an outflow housing 12. The first medium to be expanded in the region of the turbine 2 can be fed to the turbine rotor 5 via the inflow housing 11. In the area of the turbine rotor 5, relaxed first medium flows away from the turbine 2 via the outflow housing 12.

In addition to the inflow housing 11 and the outflow housing 12, the turbine housing 4 comprises an insert piece 13, the insert piece 13 extending in particular in the region of the inflow housing 11, namely adjacent to the turbine rotor 5, radially outwardly adjacent to rotor blades 14 of the turbine rotor 5.

The turbine housing 4 further comprises a nozzle ring 15. The nozzle ring 15 is also referred to as a turbine nozzle.

1 shows a sealing cover 16 in the connection area of the inflow housing 11 and the bearing housing 9. The sealing cover 16 is also referred to as a bearing housing cover or a heat shield.

The inflow housing 11 of the turbine 2 is connected to the bearing housing 9 via a fastening device 17, which is preferably designed as a clamping claw. A radially outer section of the sealing cover 15 is clamped in this connection area between the bearing housing 9 and the inflow housing 11 of the turbine. The nozzle ring is preferably also clamped with a section in this connection area.

As already stated, the turbine rotor 5 and the compressor rotor 7 are coupled via the shaft 8, which is mounted in the bearing housing 9. Bearings serve to support the shaft 8 in the bearing housing 9, namely a bearing facing the turbine 2 and a bearing facing the compressor 3 in order to support the shaft 8 along its axial extent via these bearings in at least two axial positions. 2 shows a section of a turbocharger in the area of a bearing 18 which serves to support the shaft 8 in the bearing housing 9 on a side of the shaft 8 or the bearing housing 9 facing the turbine 2 or the turbine wheel 5 of the turbine 2.

This bearing 18 facing the turbine or turbine wheel 5 is a radial sliding bearing which comprises a bearing ring or a bearing bush 19. A lubrication gap 20 is formed between the bearing ring or the bearing bush 19 and the shaft 8 and can be supplied with oil via a bore 21 in the bearing housing 9.

A cover plate 22 adjoins the bearing ring or the bearing bush 19 of the bearing 18 on the side facing the turbine 2 or the turbine wheel 5. When the bearing ring 19 or the bearing bushing of the bearing 18 is floatingly received in the bearing housing 9, the closing disk 22 limits the axial mobility of the bearing ring or the bearing bushing 19. In the case of a fixed bearing ring or a fixed bearing bushing 19, the closing disk 22 holds the bearing ring or the bearing bush 19 fixed in the axial direction.

From the lubrication gap 20 between the bearing ring 19 or the bearing bushing and the shaft 8 oil can escape during operation, also in the direction of the turbine wheel 5. To the oil tightness for the storage of the shaft 8 in the bearing housing 9 in particular adjacent to the To ensure turbine 2, according to the invention, a turbulence space 24 open in the direction of the bearing ring or the bearing bush 19 is formed in the cover plate 22, which is designed in one piece or in one piece, on an axial surface 23 facing the bearing ring or the bearing bush 19. In this turbulence chamber 24, oil which emerges from the lubrication gap 20 in the area of a bevel 25 of the bearing ring facing the turbulence chamber 24 or of the bearing bush 19 can be collected and calmed down in the turbulence chamber 24.

The turbulence chamber 24 runs around in the circumferential direction and has an oil drain opening 26 at a circumferential position, via which the oil collected and calmed in the turbulence chamber 24 can be diverted in the direction of an oil drain of the bearing housing 9. This oil drain opening 26 has an opening angle β in the circumferential direction between 5 ° and 90 °.

As already stated, the turbulence space 24 is open in the direction of the bearing ring 1 or the bearing bush 19 of the bearing 18. This turbulence space 24, which is open in the direction of the bearing ring or the bearing bush 19, is delimited on a side facing away from the bearing ring or the bearing bush 19 by a closed axial wall 27 and radially on the outside by a closed radial wall 28. Starting from the axial wall 27, which delimits the turbulence space 24 on the side facing away from the bearing ring or the bearing bushing 19 of the bearing 18, a web 29 extends in the direction of the bearing ring or the bearing bushing 19 and adjoins the turbulence chamber 24 radially on the inside on the shaft 8 limited in sections and which ends at a distance in front of the axial surface 23 of the cover disk 22 facing the bearing ring or the bearing bush 19. The web 29 accordingly has an axial length that is less than the axial thickness or width of the closing disk 22.

The web 29, which defines a sealing gap 30 towards the shaft 8, has an axial length which is between 0.1 times and 0.7 times the axial thickness or axial width of the cover plate 22.

The radial width of the sealing gap 30 between the web 29 of the cover plate 22 and the shaft 8 is between twice and 20 times the radial bearing play between the bearing ring 19 of the bearing 18 and the shaft 8. In order to optimally absorb the oil escaping from the lubrication gap 20 of the bearing 18 in the area of the swirl space 24, which is open in the direction of the bearing ring or the bearing bush 19, the swirl space 24 is particularly contoured in such a way that an extension of that bevel 25 of the bearing ring or the bearing bush 19, which diverges in the direction of the swirl space 24, intersects the closed axial wall 27 which delimits the swirl space 24 on the side facing away from the bearing ring or the bearing bush 19.

In Fig. 3, this extension of the bevel 25 is shown in dashed lines. The extension of the bevel 25 intersects the closed axial wall 27, in particular in the transition area to the closed radial wall 28, which delimits the turbulence space 24 radially on the outside.

With the invention it is proposed that in the cover 22, which is arranged between the turbine wheel 5 and the bearing 18, which supports the shaft 8 on the side facing the turbine 2 in the bearing housing 9, a towards the bearing ring or the bearing bush 19 of the bearing 18 open swirl space 24 is introduced. Oil that emerges from the lubrication gap 20 between the bearing ring or the bearing bush 19 of the bearing 18 and the shaft 8 reaches the area of the swirl space 24, is caught and calmed there and via the swirl space 24 running in the circumferential direction towards the oil drain opening 26 the cover plate 22 out. In this way, the collected oil can be drained off in a defined manner.

The turbulence space 24 is delimited radially on the inside by the web 29, radially on the outside by the radial wall 28 and on the side facing away from the bearing ring or the bearing bush 19 by the axial wall 27. An extension of the bevel 25 of the bearing ring or the bearing bushing preferably intersects 19 this axial wall 27. Adjacent to the bearing ring or the bearing bush 19, the turbulence space 24 is open.

In the area of that bearing which supports the shaft 8 on the side facing the compressor 3, a cover plate, as described above, can also be arranged.

List of reference symbols

1 Turbocharger 2 Turbine 3 Compressor 4 Turbine housing 5 Turbine rotor 6 Compressor housing 7 Compressor rotor 8 Shaft 9 Bearing housing 10 Muffler 11 Inflow housing 12 Outflow housing 13 Insert 14 Blade 15 Nozzle ring 16 Sealing cover 17 Fastening device 18 Bearing 19 Bearing ring / bearing bush 20 Lubricating gap 21 Bore 22 Cover plate 23 Axial surface 24 swirl space 25 chamfer 26 oil drain opening 27 axial wall 28 radial wall 29 web 30 radial gap

Claims (10)

1. Turbocharger (1), with a turbine (2) for expanding a first medium, the turbine (2) having a turbine housing (4) and a turbine rotor (5), with a compressor (3) for compressing a second medium using energy obtained in the turbine (2) when the first medium is expanded, the compressor (3) having a compressor housing (6) and one with the turbine rotor (5) via a shaft (8) has coupled compressor rotor (7), with a bearing housing (9) arranged between the turbine housing (4) and the compressor housing (6), in which the shaft (8) is mounted via a bearing (18) facing the turbine (2), with a cover plate (22) which adjoins the bearing ring or the bearing bush (19) on a side of a bearing ring facing the turbine (2) or a bearing bushing (19) of the bearing (18) facing the turbine (2) ,that a turbulence chamber (24) open in the direction of the bearing ring or the bearing bushing (19) is introduced into the end disk (22) on an axial surface (23) facing the bearing ring or the bearing bushing (19) of the bearing (18) facing the turbine (2) is, the oil that emerges from a lubrication gap (20) of the bearing (18), catches and drains. 2. Turbocharger according to claim 1, characterized in that the cover plate (22) is formed in one piece. 3. Turbocharger according to claim 1 or 2, characterized in that the swirl space (24) runs around in the circumferential direction and has an oil drain opening (26) at a circumferential position. 4. Turbocharger according to claim 3, characterized in that the oil drain opening (26) has an opening angle in the circumferential direction between 5 ° and 90 °. 5. Turbocharger according to one of claims 1 to 4, characterized in that the turbulence space (24) of the cover plate (22) open in the direction of the bearing ring or the bearing bush (19) is provided on a side facing away from the bearing ring or the bearing bush (19) by a closed axial wall (27) and is limited on a radially outer side by a closed radial wall (28). 6. Turbocharger according to claim 5, characterized in that the open swirl space (24) is contoured in such a way that an extension of a bevel (25) of the bearing ring or the bearing bush (19) facing the swirl space (24) intersects the closed axial wall (27). 7. Turbocharger according to claim 6, characterized in that the extension of the bevel (25) of the bearing ring (19) or the bearing bush (19) facing the swirl chamber (24) intersects the closed axial wall (27) in the transition area to the closed radial wall (28). 8. Turbocharger according to one of claims 1 to 7, characterized in that the turbulence space (24) of the end disk (22) open in the direction of the bearing ring or the bearing bush (19) is provided on a radially inner side facing the shaft (8) Web (29) is limited. 9. Turbocharger according to claim 8 and 9, characterized in that the web (29) starting from the axial wall (27) which delimits the open turbulence space (27) on the side facing away from the bearing ring or the bearing bush (19), in the direction extends onto the axial surface (23) facing the bearing ring or the bearing bushing (19) and ends at a distance in front of this axial surface (23). 10. Turbocharger according to claim 8 or 9, characterized in that the web (29) defines a sealing gap (30) to the shaft (8), the axial length of which is between 0.1 times and 0.7 times the axial thickness of the Closing disk (22) and / or its radial width is between 2 and 20 times the radial bearing play between the bearing ring (19) or the bearing bush and the shaft (8).