Bearing housing of an exhaust-gas turbocharger

Abstract

A bearing housing (1) of an exhaust-gas turbocharger, having a compressor-side housing flange (2), a central housing section (3) which is integrally connected to the housing flange (2) and in which a first partial section (4) of an oil chamber (5) is arranged; and a turbine-side housing section (6) which has a turbine-side housing flange (7) and in which a second partial section (8) of the oil chamber (5) is formed. The central housing section (3) and the turbine-side housing section (6) are formed in one piece. A bearing housing (9) which forms a separate component is inserted into the central housing section (3) and into the turbine-side housing section (6), with these delimiting the oil chamber (5).

Claims

1. A bearing housing (1) of an exhaust-gas turbocharger, with a compressor-side housing flange (2), a turbine-side housing flange (7), and a central housing section (3) which is integrally connected to the compressor-side housing flange (2) and turbine-side housing flange (7), and in which an oil inlet bore (20) having a single inlet opening and a single outlet opening is arranged; wherein a bearing sleeve (9), having an outer circumferential surface, an inner cylindrical bore, and oil inflow ducts (11, 12), each oil inflow duct having a single inlet opening and a single outlet opening, as a separate component is inserted into the central housing section (3) and fixed against rotation an axially extending oil supply channel (4) in communication with the oil inlet bore (20) outlet opening and the oil inflow duct (11, 12) inflow openings, and an oil collection chamber (5), are defined between the bearing sleeve (9) outer circumferential surface and the central housing section (3), said oil supply channel (4) and said oil collection chamber (5) being separated at the outer circumferential surface of the bearing sleeve (9) by a barrier, and axially spaced journal bearings are inserted in the inner cylindrical bore of the bearing sleeve (9), wherein the oil inlet bore (20), oil supply channel (4) and oil inflow ducts (11, 12) are in communication with the journal bearings, and wherein the bearing housing extends axially between a compressor end and a turbine end, and wherein the bearing sleeve (9) extends axially in the direction of the turbine beyond the turbine end of the bearing housing (1).

2. The bearing housing (1) as claimed in claim 1, wherein the bearing sleeve (9) is substantially cylindrical and of constant diameter to the extent housed in the bearing housing (1).

3. A bearing housing (1) of an exhaust-gas turbocharger, with a compressor-side housing flange (2), a turbine-side housing flange (7), and a central housing section (3) which is integrally connected to the compressor-side housing flange (2) and turbine-side housing flange (7), and in which an oil inlet bore (20) having a single inlet opening and a single outlet opening is arranged; wherein a bearing sleeve (9), having an outer circumferential surface, an inner cylindrical bore, and oil inflow ducts (11, 12), each oil inflow duct having a single inlet opening and a single outlet opening, as a separate component is inserted into the central housing section (3) and fixed against rotation an axially extending oil supply channel (4) in communication with the oil inlet bore (20) outlet opening and the oil inflow duct (11, 12) inflow openings, and an oil collection chamber (5), are defined between the bearing sleeve (9) outer circumferential surface and the central housing section (3), said oil supply channel (4) and said oil collection chamber (5) being separated at the outer circumferential surface of the bearing sleeve (9) by a barrier, and axially spaced journal bearings are inserted in the inner cylindrical bore of the bearing sleeve (9), wherein the oil inlet bore (20), oil supply channel (4) and oil inflow ducts (11, 12) are in communication with the journal bearings, and a water chamber (10) is provided which is separate from the oil chamber (5) and which is delimited by the central housing section (3) and the bearing sleeve (9).

4. The bearing housing (1) as claimed in claim 3, wherein the water chamber (10) is of semi-circular design.

5. The bearing housing (1) as claimed in claim 3, wherein the water chamber (10) is provided with two water ports (13, 14).

6. The bearing housing (1) as claimed in claim 3, wherein the water chamber (10) has only one water port (13).

7. A bearing housing (1) of an exhaust-gas turbocharger, with a compressor-side housing flange (2), a turbine-side housing flange (7), and a central housing section (3) which is integrally connected to the compressor-side housing flange (2) and turbine-side housing flange (7), and in which an oil inlet bore (20) having a single inlet opening and a single outlet opening is arranged; wherein a bearing sleeve (9), having an outer circumferential surface, an inner cylindrical bore, and oil inflow ducts (11, 12), each oil inflow duct having a single inlet opening and a single outlet opening, as a separate component is inserted into the central housing section (3) and fixed against rotation an axially extending oil supply channel (4) in communication with the oil inlet bore (20) outlet opening and the oil inflow duct (11, 12) inflow openings, and an oil collection chamber (5), are defined between the bearing sleeve (9) outer circumferential surface and the central housing section (3), said oil supply channel (4) and said oil collection chamber (5) being separated at the outer circumferential surface of the bearing sleeve (9) by a barrier, and axially spaced journal bearings are inserted in the inner cylindrical bore of the bearing sleeve (9), wherein the oil inlet bore (20), oil supply channel (4) and oil inflow ducts (11, 12) are in communication with the journal bearings, and a heat decoupling chamber (25) is provided which, at its end pointing toward the shaft (16), is closed off by the bearing sleeve (9).

Description

(1) Further details, advantages and features of the invention will emerge from the following description of exemplary embodiments on the basis of the drawing, in which:

(2) FIG. 1 shows a schematically slightly simplified illustration of a turbocharger body group which is provided with a bearing housing according to the invention,

(3) FIG. 2 shows a sectional illustration of the bearing housing according to the invention before the insertion of a bearing sleeve,

(4) FIG. 3 shows a perspective illustration of the bearing housing according to the invention after the insertion of the bearing sleeve and the assembly of a rotor,

(5) FIG. 4 shows a perspective simplified illustration of a known bearing housing design,

(6) FIG. 5 shows a perspective illustration of a core for forming the bearing housing according to FIG. 4,

(7) FIG. 6 shows an illustration, corresponding to FIG. 4, of a bearing housing according to the invention,

(8) FIG. 7 shows an illustration, corresponding to FIG. 5, of a core which can be used when carrying out the method according to the invention,

(9) FIG. 8 shows an illustration, corresponding to FIG. 7, of an alternative inner core,

(10) FIG. 9 shows a schematically highly simplified diagrammatic illustration of a water chamber produced by means of the core of FIG. 8,

(11) FIG. 10 shows an illustration, corresponding to FIG. 1, of a part of an alternative embodiment of the bearing housing according to the invention, and

(12) FIG. 11 shows a perspective illustration of said part of the alternative embodiment of the bearing housing according to the invention.

(13) FIG. 1 illustrates an exhaust-gas turbocharger body group which has a bearing housing 1 according to the invention. The body group also includes a shaft 16 on which the compressor wheel 15 is mounted at one side and the turbine wheel 19 is mounted at the other side so as to form a rotor. The shaft 16 is mounted in the bearing housing 1 by means of a compressor-side bearing arrangement 17 and a turbine-side bearing arrangement 18 together with an axial bearing 22. If a compressor housing and a turbine housing, which are not illustrated in FIG. 1, are added to said body group, this yields an exhaust-gas turbocharger, such that the present invention can also be described as an exhaust-gas turbocharger with a bearing housing 1 to be described in detail below.

(14) FIG. 2 illustrates the bearing housing 1 according to the invention before the insertion of a bearing sleeve 9. The bearing housing 1 comprises a compressor-side housing flange 2, a central housing section 3 which is integrally connected to the housing flange 2 and in which a first partial section 4 (see FIG. 1) of an oil chamber 5 is arranged, and a turbine-side housing section 6 which has a turbine-side housing flange 7 and in which a second partial section 8 (see FIG. 1) of the oil chamber 5 is arranged. The oil inlet 20 and the oil outlet 21 can also be seen from said illustration.

(15) The central housing section 3 and the turbine-side housing section 6 are formed in one piece, and the bearing sleeve 9, which forms a separate component, is inserted in the central housing section 3 and turbine-side housing section 6. The advantage of said arrangement is that the bearing sleeve 9 and the two housing sections 3 and 6 together delimit the oil chamber 5.

(16) It can also be seen from FIGS. 1 to 3 that the oil chamber 5 is separate from a water chamber 10 which is delimited by the turbine-side housing section 6 and by the bearing sleeve 9. As is also shown in FIG. 1, the bearing sleeve 9 is provided with oil inlet ducts 11, 12.

(17) In an alternative embodiment, the bearing sleeve 9 may be divided into two sleeve parts which, in the assembled state, are inserted in alignment one behind the other in the central housing section 3 and the turbine-side housing section 6. FIG. 3 also shows the assembled rotor (compressor wheel 15, shaft 16 and turbine wheel 19) and water ports 13, 14 of the water chamber 10.

(18) FIG. 4 shows a perspective illustration of a known bearing housing design LG, viewed from the direction of the turbine wheel. In this case, the bearing housing LG has a circular-ring-shaped water chamber WR with four water ports WA.sub.1 to WA.sub.4 and has an oil chamber OR.

(19) FIG. 5 shows a perspective illustration of a core K for manufacturing the water chamber WR and the oil chamber ÖR. For this purpose, the core has a water core WAK and an oil core ÖK which is combined with said water core.

(20) FIG. 6 shows the bearing housing 1 according to the invention, viewed again from the direction of the turbine wheel (not illustrated in FIG. 6). Here, FIG. 6 shows the semi-circular design of the water chamber 10 with, in contrast to the known embodiment of FIG. 4, only two water ports 13 and 14 and the oil chamber 5 which is separate from the water chamber 10.

(21) FIG. 7 shows a combined oil/water core 23 suitable for said housing design. Said core 23 has a water core 10.sub.WK with two water port cores 13.sub.AK and 14.sub.AK. Said water core 10.sub.WK is combined with the oil core 5.sub.ÖK, as emerges in detail from FIG. 7.

(22) The method according to the invention which can be carried out with the core 23 has the following method steps:

(23) casting a single-piece bearing housing shell;

(24) separately manufacturing the bearing sleeve 9; and

(25) inserting the bearing sleeve 9 into the bearing housing shell.

(26) The advantage of the method according to the invention is that, during the casting process, a single-piece bearing housing shell with a water chamber 10 and an oil chamber 5 is produced. As can be seen from FIG. 7, the combined oil/water core 23 is used to produce the oil chamber 5 and the water chamber 10. What has proven to be advantageous in this embodiment is the division into a water core 10.sub.WK, with the two water port cores 13.sub.AK, 14.sub.AK, and the oil core 5.sub.ÖK.

(27) FIG. 8 illustrates an alternative core 23′ in which the water core 10.sub.WK has only one water port core 13.sub.AK.

(28) FIG. 9 shows a highly simplified diagrammatic illustration of the water port from FIG. 8, with the water inlet and outlet being combined to form one port by means of an adaptor port 24.

(29) FIGS. 10 and 11 show an alternative embodiment of the bearing housing 1 according to the invention. Said embodiment has a heat decoupling chamber 25 which is arranged in the turbine-side housing section 6 and whose lower opening which points toward the shaft is closed off in the assembled state by the bearing sleeve 9, as can be seen in detail from the illustrations of FIGS. 10 and 11.

(30) Here, FIG. 10 in particular shows that said heat decoupling chamber has a small axial extent in relation to its large radial extent. With said embodiment, it is possible for no water chamber to be provided.

(31) To supplement the above written disclosure, reference is explicitly made to the diagrammatic illustration of the invention in FIGS. 1 to 11.

LIST OF REFERENCE SYMBOLS

(32) 1 Bearing housing 2 Compressor-side housing flange 3 Central housing section 4 First partial section 5 Oil chamber 5.sub.ÖK Oil core 6 Turbine-side housing section 7 Turbine-side housing flange 8 Second partial section 9 Bearing sleeve 10 Water chamber 10.sub.WK Water core 11, 12 Oil inlet ducts 13, 14 Water ports 13.sub.AK Water port core 14.sub.AK Water port core 15 Compressor wheel 16 Shaft 17 Bearing arrangement 18 Turbine-side bearing arrangement 19 Turbine wheel 20 Oil inlet 21 Oil outlet 22 Axial bearing 23 Combined oil/water core 23′ Alternative core 24 Adapter port 25 Heat decoupling chamber K Core LG Bearing housing ÖK Oil core ÖR Oil chamber WAK Water core WR Water chamber WA.sub.1-WA.sub.4 Water ports