Exhaust gas guide for an exhaust gas turbocharger and method for operating an exhaust gas turbocharger
An exhaust gas guide section for an exhaust gas turbocharger includes an actuator ( 1 ) with a wastegate ( 9 ) for opening and closing a bypass channel ( 31 ) of the exhaust gas guide section ( 1 ), wherein the bypass channel ( 31 ) is provided in the exhaust gas guide section ( 1 ) that can be flowed through to bypass a turbine wheel of the exhaust gas guide section ( 1 ) which is rotatably arranged in the exhaust gas guide section ( 1 ) in a wheel chamber of the exhaust gas guide section ( 1 ), and wherein the bypass channel ( 31 ) has a second flow cross section ( 33 ).
1. An exhaust gas guide section ( 1 ) for an exhaust gas turbocharger, comprising:
a first spiral channel ( 4 ) and a second spiral channel ( 5 ) formed in the exhaust gas guide section ( 1 ),
the first spiral channel ( 4 ) and the second spiral channel ( 5 ) being separated from
a bypass duct ( 31 ) by
a first wall ( 19 ) and separated from one another by
a second wall ( 29 );
a through-flow opening ( 10 ) formed in the second wall ( 29 ) between the first spiral channel ( 4 ) and the second spiral channel ( 5 ); and
a wastegate ( 9 ) for opening and closing the bypass duct ( 31 ) of the exhaust gas guide section ( 1 ), the wastegate having
a body ( 15 ) firmly connected to
a base plate ( 13 ) for opening and closing
an inlet opening ( 32 ) of the bypass duct ( 31 ) in the first wall ( 19 ),
wherein the wastegate ( 9 ) has a groove ( 28 ) formed along an outer circumference of the body ( 15 ), and
wherein a projection ( 30 ) is formed in the second wall ( 29 ), the projection ( 30 ) being aligned with the body ( 15 ) of the wastegate ( 9 ) to engage the groove ( 28 ) when the wastegate ( 9 ) is completely closed, thereby providing a reliable seal between the first spiral channel ( 4 ) and the second spiral channel ( 5 ),
wherein, in an intermediate position of the wastegate ( 9 ), the through-flow opening ( 10 ) is completely closed and the inlet opening ( 32 ) of the bypass duct ( 31 ) is partially open, and wherein the groove has a width (BR) and extends along a transverse axis ( 26 ) across a top surface ( 23 ) of the wastegate ( 9 ).
2. The exhaust gas guide section according to claim 1 , wherein the body ( 15 ) has a pot-shaped outer contour ( 12 ).
3. The exhaust gas guide section according to claim 1 ,
wherein the body ( 15 ) of the wastegate ( 9 ) comprises a first portion ( 20 ) and a second portion ( 21 ) along its longitudinal axis ( 22 ),
wherein a first angle of inclination (α 1 ) of a first outer surface 24 of the first portion ( 20 ) is greater than a second angle of inclination (α 2 ) of a second outer surface ( 25 ) of the second portion ( 21 ), and
wherein the second portion ( 21 ) is arranged opposite the second wall ( 29 ).
4. The exhaust gas guide section according to claim 3 ,
wherein the wastegate ( 9 ) comprises an annular surface ( 18 ), which bears against the first wall ( 19 ) of the exhaust gas guide section ( 1 ).
5. The exhaust gas guide section according to claim 4 ,
wherein the wastegate ( 9 ) is mounted at a lever arm ( 38 ) which may be swivelled about an axis of rotation ( 34 ), the axis of rotation being arranged in a common plane with the annular surface ( 18 ).
6. The exhaust gas guide section according to claim 1 , wherein both the base plate ( 13 ) and the body ( 15 ) have oval cross-sectional shapes.
7. The exhaust gas guide section according to claim 1 , wherein the top surface ( 23 ) of the groove ( 28 ) which faces the projection ( 30 ) is flat.