An exhaust-gas turbocharger (1) having a wastegate arrangement (5) in which the structural adaptability to different installation situations and the sealing action of the wastegate arrangement (5) are improved. The rotor (4) extends along a charger axis (L). The wastegate arrangement (5) has a control capsule (6), a regulating rod (7) which can be moved by the control capsule (6), a lever (8) which is connected to the regulating rod (7) by means of a guide piece (9), and a spindle shaft (10) which is connected at one end to the lever (8) and at the other end to a spindle (11) which bears a flap plate (12) for opening and closing a bypass opening (13). Here, the spindle shaft (10) is arranged substantially parallel to the charger axis (L).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an exhaust-gas turbocharger in which the structural adaptability to different installation situations and the sealing action of the wastegate arrangement are improved.

2. Description of the Related Art

Known exhaust-gas turbochargers with a so-called wastegate arrangement have a flap plate which can be actuated by means of a control capsule and a lever mechanism and which regulates the throughput of a bypass opening which leads directly from the inlet region of the spiral of the turbine housing to the outlet out of the turbine. Since the spiral is heated up very intensely by the hot exhaust gases, in particular in the inlet region, sealing problems arise in the known designs on account of the thermal loadings, which sealing problems are exacerbated in that the flap plate, in the open state, is impinged on directly by the main flow of the exhaust gas discharged by the turbine wheel.

Furthermore, the spindle shaft of known exhaust-gas turbochargers with a wastegate arrangement runs perpendicular to the charger axis, such that the regulating rod together with the control capsule is aligned substantially axially with respect to the charger axis, which leads in part to space problems and therefore to problems during the installation of the exhaust-gas turbocharger.

It is therefore an object of the present invention to create an exhaust-gas turbocharger of the type specified in the preamble of claim1which can be better adapted to different installation situations and which enables an improvement in the sealing action of the wastegate arrangement.

BRIEF SUMMARY OF THE INVENTION

The object is achieved by arrangement of the spindle shaft parallel to the charger axis.

In particular, the arrangement of the spindle shaft parallel to the charger axis makes it possible for the regulating rod to be arranged substantially at right angles with respect to the charger axis and to thereby position the control capsule radially, which yields installation space advantages for certain installation conditions.

Furthermore, it is made possible for the bypass opening to be arranged at one end of a bypass duct whose other end is flow-connected to the spiral of the turbine housing. This results in cooling of the exhaust-gas flow impinging on the flap plate, which increases the sealing action since thermal decoupling of the flap plate is made possible at least to a certain extent by means of the bypass duct, which acts as a cooling path.

Furthermore, the provision of a line or bypass duct of the type provides greater freedom for positioning the flap, which in a particularly preferred embodiment permits an arrangement outside the exhaust-gas main flow passing from the turbine wheel, which yields a further improvement of the sealing action of the flap plate.

Furthermore, it is made possible for the turbine housing to be formed as a sheet-metal housing, which above all yields production advantages and therefore cost advantages.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1illustrates an exhaust-gas turbocharger1which comprises a compressor2and a turbine3which are connected to one another in the usual way by means of a shaft4. As shown inFIG. 1, the shaft4extends along the charger axis L and, at its ends, bears a turbine wheel19and a compressor wheel20in the usual way. The exhaust-gas turbocharger1is provided with a known wastegate arrangement WG with a control capsule SD. In the exhaust-gas turbocharger1according to the invention with its basic components as explained above, the known wastegate arrangement WG is replaced by a wastegate arrangement5according to the invention, which will be described in detail below.

A description of all other components, which of course likewise encompasses the said exhaust-gas turbocharger1, may however be omitted for the explanation of the principles of the present invention.

The exhaust-gas turbocharger1according to the invention is therefore explained in detail below on the basis of a description of a juxtaposition ofFIGS. 2-4.

The wastegate arrangement5comprises a control capsule6, a regulating rod7which can be moved by the control capsule6, a lever8which is connected to the regulating rod7by means of a guide piece9, and a spindle shaft10.

The spindle shaft10is connected at one end to the lever8and at the other end to a spindle11which bears a flap plate12for opening and closing a bypass opening13.

As can be seen in particular fromFIG. 3, the spindle shaft10is arranged substantially parallel, and preferably exactly parallel, to the charger axis L.

Furthermore, the regulating rod7is arranged substantially at right angles to the charger axis L, as can be seen fromFIG. 3.

As is also illustrated in detail inFIG. 2, the bypass opening13is arranged at one end of a bypass duct14whose other end is flow-connected to the spiral15of the turbine housing16.

As illustrated inFIG. 4, the bypass duct14opens with its bypass opening13into an elongate housing-side flange17outside a region of an outlet opening18of the main exhaust-gas flow of the turbine housing16.

In addition to the above written disclosure of the invention, reference is hereby additionally explicitly made to the diagrammatic illustration thereof inFIGS. 1 to 4.

LIST OF REFERENCE SYMBOLS