초록

In the generic exhaust-gas turbocharger, the turbine-side and compressor-side radial bearing bush are of identical design. A more compact bearing space, and improvements in acoustics and rotor dynamics, are achieved by providing different bearings on the turbine and compressor sides.

대표청구항 ▼

1. An exhaust-gas turbocharger (1) having a compressor (2) comprising a compressor housing;a turbine (3) comprising a turbine housing;a bearing housing (4) which is connected at one end to the compressor housing and at the other end to the turbine housing, andwhich has an oil supply, and which has a

1. An exhaust-gas turbocharger (1) having a compressor (2) comprising a compressor housing;a turbine (3) comprising a turbine housing;a bearing housing (4) which is connected at one end to the compressor housing and at the other end to the turbine housing, andwhich has an oil supply, and which has an oil collecting chamber (6) at a turbine-side end (5) andwhich has a bearing arrangement (7) for a rotor shaft (8), which bearing arrangement comprises: turbine-side and compressor-side receiving bores (9″, 10″),a compressor-side bearing bush (9) with a radially inner bearing surface forming a gap with the rotor shaft (8) and a radially outer circumferential surface facing the compressor-side receiving bore (9″), anda turbine-side bearing bush (10) which is spaced apart axially from the compressor-side bearing bush (9) and which has a radially inner bearing surface (11) forming a gap with the rotor shaft (8) and a radially outer circumferential surface (12) facing the turbine-side receiving bore (10″), wherein the inner axial bearing surface width of the compressor-side bearing bush (9) differs from the inner axial bearing surface width of the turbine-side bearing bush (10),the outer axial bearing surface width of the compressor-side bearing bush (9) differs from the outer axial bearing surface width of the turbine-side bearing bush (10) orthe inner axial bearing surface width of the compressor-side bearing bush (9) differs from the inner axial bearing surface width of the turbine-side bearing bush (10) and the outer axial bearing surface width of the compressor-side bearing bush (9) differs from the outer axial bearing surface width of the turbine-side bearing bush (10). 2. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the outer diameter of the rotor shaft (8) in the region of the compressor-side bearing bush (9′) and/or the outer diameter of the rotor shaft (8) in the region of the turbine-side bearing bush (10) is larger than the rotor shaft diameter between the bearing bushes (9, 10). 3. The exhaust-gas turbocharger (1) as claimed in claim 2, wherein the diameter enlargement is realized by the provision of a slight bevel or by the provision of a shaft shoulder. 4. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the compressor-side bearing bush (9) outer diameter is larger or smaller than the outer diameter of the turbine-side bearing bush (10). 5. The exhaust-gas turbocharger (1) as claimed in claim 4, wherein the inner diameter of the compressor-side bearing bush (9) is larger or smaller than the inner diameter of the turbine-side bearing bush (10). 6. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the inner bearing surfaces (11) and/or the outer bearing surfaces (17) of the bearing bushes (9, 10) are of different design. 7. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein receiving bores (9″, 10″) for the bearing bushes (9, 10) in the bearing housing (4) are of different design with regard to bore diameter and/or bore width. 8. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein inner surfaces of the receiving bores of the bearing housing (4) are of different design. 9. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the turbine-side bearing bush (10) extends into the region of the oil collecting chamber (6). 10. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the radially inner bearing surface (11) of the compressor-side bearing bush (9) or the turbine-side bearing bush (10) is split into two spaced-apart bearing surface regions (13, 14). 11. The exhaust-gas turbocharger (1) as claimed in claim 10, wherein the bearing surface regions (13, 14) are separated from one another by a radially outwardly recessed clearance (15). 12. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the turbine-side bearing bush (10) is of symmetrical design with a continuous outer circumferential surface (12). 13. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein an outer circumferential surface (12) of the turbine-side bearing bush (10) is split into two outer circumferential surface regions (17, 18) by a shoulder (16), one outer circumferential region (17) having a greater outer diameter, the other outer circumferential region (18) having a smaller outer diameter. 14. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the bearing bushes (9, 10) are held spaced apart axially along the rotor shaft (8) by a spacer arrangement (19). 15. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the bearing bushes (9, 10), spaced apart axially by means of a spacer arrangement (19), are combined to form one component. 16. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein inner surfaces of the receiving bores of the bearing housing (4) are of different design and are provided with a sickle-shaped groove (20) arranged on circumferential segments. 17. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the inner axial bearing surface width of the compressor-side bearing bush (9) differs from the inner axial bearing width of the turbine-side bearing bush (10). 18. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the outer axial bearing surface width of the compressor-side bearing bush (9) differs from the outer axial bearing surface width of the turbine-side bearing bush (10). 19. The exhaust-gas turbocharger (1) as claimed in claim 1, wherein the inner and outer axial bearing surfaces width of the compressor-side bearing bush (9) differ from the inner and outer axial bearing surfaces width of the turbine-side bearing bush (10).