Turbocharger

Abstract

A turbocharger, with a turbine for expanding a first medium that includes a turbine rotor and a turbine housing, a compressor for compressing a second medium that includes a compressor rotor coupled to the turbine rotor via a shaft and a compressor housing, a bearing housing in which the shaft is mounted, a bearing housing cap delimiting the bearing housing facing the turbine, and a turbine cover delimiting the turbine on a side facing the bearing housing and has a section projecting into a recess of the bearing housing cap. On a section of the bearing housing cap delimiting the recess of the bearing housing cap on the outside, which on the outside follows the section of the turbine cover projecting into the recess of the bearing housing cap, an oil trapping lip is formed on a side of the bearing housing cap facing the turbine rotor.

Claims

1. A turbocharger, comprising: a shaft; a turbine configured to expand a first medium, and having: a turbine rotor; and a turbine housing; a compressor configured to compress a second medium utilizing energy extracted in the turbine during expansion of the first medium, and having: a compressor rotor coupled to the turbine rotor via the shaft; and a compressor housing; a bearing housing, in which the shaft is mounted; a bearing housing cap delimiting the bearing housing on a side facing the turbine; a turbine cover delimiting the turbine on a side facing the bearing housing, which follows the bearing housing cap and which has a section that projects into a recess of the bearing housing cap; and an oil trapping lip is formed on a section of the bearing housing cap delimiting the recess of the bearing housing cap, and the oil trapping lip is formed in a position in an axial direction adjacent to the section of the turbine cover projecting into the recess of the bearing housing cap, wherein the axial direction is defined by the shaft, and wherein the oil trapping is formed on a side of the bearing housing cap facing the turbine rotor.

2. The turbocharger according to claim 1, wherein the oil trapping lip is formed by a protrusion and a groove.

3. The turbocharger according to claim 2, wherein the protrusion of the oil trapping lip has a smaller clearance from the turbine rotor than the groove of the oil trapping lip.

4. The turbocharger according to claim 2, wherein the protrusion of the oil trapping lip extends, from a radially inside facing surface of the oil trapping lip at an oblique position relative to a radial direction in a direction of the turbine rotor.

5. The turbocharger according to claim 2, wherein the groove of the oil trapping lip is open to a radially inside direction and faces the section of the turbine cover.

6. The turbocharger according to claim 1, wherein on the section of the turbine cover projecting into the recess of the bearing housing cap an oil trapping slope is formed on the side facing the turbine rotor.

7. The turbocharger according to claim 6, wherein the oil trapping lip is disposed directly above the oil trapping slope in a radial direction with a clearance between the oil trapping lip and the oil trapping slope in the radial direction.

8. The turbocharger according to claim 7, wherein the oil trapping lip of the bearing housing cap directs oil onto the oil trapping slope of the turbine cover, and the oil trapping slope of the turbine cover directs the oil into a turbine flow duct.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred further developments of the invention are obtained from the subclaims and the following description. Exemplary embodiments of the invention are explained in more detail by way of the drawing without being restricted to this. It shows:

(2) FIG. 1 is a cross section through a turbocharger;

(3) FIG. 2 is a detail of a turbocharger according to the prior art;

(4) FIG. 3 is a further detail of a turbocharger according to the prior art;

(5) FIG. 4 is a detail of a turbocharger; and

(6) FIG. 5 is a further detail of a turbocharger.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(7) The invention present here relates to a turbocharger. The fundamental construction of a turbocharger according to the prior art and the problems of such turbochargers known from the prior art were already described with reference to FIGS. 1, 2 and 3. In the following, only details of a turbocharger according to the invention are discussed, namely making reference to FIGS. 4 and 5.

(8) FIGS. 4 and 5 show details of a turbocharger according to one aspect of the invention, namely sections which with respect to their positioning, correspond to the details of FIGS. 2 and 3. Accordingly, FIG. 4 shows in particular a bearing housing cap 16 and a turbine cover 17, wherein the bearing housing cap 16 axially delimits the bearing housing 9 and the turbine cover 17 axially delimits the turbine 2. A radially outer, upper section 17a of the turbine cover 17 projects into a recess 16a of the bearing housing cap 16, wherein this recess 16a is delimited radially outside by a section 16b of the bearing housing cap 16, which forms the sealing gap 18 with the bearing housing 9. In the turbocharger according to the invention it is provided that on the section 16b of the bearing housing cap 16 delimiting the recess 16a of the bearing housing cap 16 on the outside, which follows the section 17b of the turbine cover 17 projecting into the recess 16a on the outside, an oil trapping lip 22 is formed, namely on the side of the bearing cap 16 facing the turbine rotor 5 or the moving blades 14 of the turbine rotor 5.

(9) According to FIG. 4, this oil trapping lip 22 is formed by a protrusion 23 and a groove 24, wherein the protrusion 23 has a smaller clearance 5 from the moving blades 14 of the turbine rotor 5 than the groove 24.

(10) The protrusion 23 of the oil trapping lip 22 extends, starting out from the section 16 of the bearing housing cap 16, to radially inside, obliquely positioned relative to the radial direction in the direction of the turbine rotor 5. The groove 24 of the oil trapping lip 22 is open to radially inside and faces the section 17a of the turbine cover 17, which projects into the recess 16a of the bearing housing cap 16.

(11) Oil, which flows through the sealing gap 18 between the bearing housing 9 and the bearing housing cap 16 according to the arrow 20 in the direction of the turbine rotor 5, reaches the oil trapping lip 22 and is trapped on the same, namely both in the region of the protrusion 23 and also in the region of the groove 24. Because of this it can be avoided that the oil enters a cap between the bearing housing cap 16 and the turbine cover 17.

(12) In a further development of the invention it is provided that on the section 17a of the turbine cover 17 projecting into the recess 16a of the bearing housing cap 16 an oil trapping slope 25 is formed on the side of the turbine rotor 5 or the moving blades 14 facing the same, wherein the oil trapping lip 24 directs oil, which is trapped on the oil trapping lip, onto the oil trapping slope 25. Then, the oil trapping slope 25 guides the oil according to the arrows 26 along the side of the turbine cover 17 facing the turbine rotor 5 and conducts the same into a turbine flow duct 27 of the turbine or of the inflow housing 11 of the turbine housing 4 of the turbine 2. Here, the oil is combusted so that there is no risk that the same escapes into the surroundings.

(13) According to FIG. 4, the oil trapping lip 22 protrudes over the oil trapping slope 25 radially outside at least in sections, namely with clearance in the radial direction. The oil trapping slope 25 is bevelled in such a manner that seen in the axial direction an outer tip of the section 17a of the turbine cover 17 covers neither the protrusion 22 nor the groove 24 of the oil trapping lip 22.

(14) Oil trapped on the oil trapping lip 22 can reach the oil trapping slope 25 without obstruction and can be guided by the oil trapping slope 25 according to the arrows 26 in the direction of the turbine flow duct 27.

(15) Seen in the axial direction, the radially outer tip of the section 17a of the turbine cover 17 has a larger clearance from the turbine rotor 5 or the moving blades 14 of the same than the sealing lip 22, namely than the protrusion 23 and the groove 24 of the oil trapping lip 22.

(16) With the invention, oil, which escapes from the bearing housing 9 via the sealing gap 18 between sealing cover 16 and bearing housing 9, can be safely discharged into the turbine flow duct 27 of the inflow housing 11 of the turbine housing 4 and combusted there. The risk that such oil enters the surroundings via a gap between bearing housing cap 16 and turbine cover 17 is minimised.

(17) Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.