Variable turbine and/or compressor geometry for an exhaust gas turbocharger

An exhaust gas turbocharger, comprising:

• at least one of a variable turbine geometry and a variable compressor geometry, the at least one of the variable turbine geometry and the variable compressor geometry including:
• a housing including a first housing wall and a second housing wall, the first housing wall together with the second housing wall at least partially defining a housing interior;
• a blade bearing ring including at least one guide blade rotatably mounted thereon;
• a control lever for adjusting the at least one guide blade between a closing position and an opening position;
• and
• an actuating shaft connected rotationally fixed to the control lever and being rotatable along a rotation axis, wherein the actuating shaft is rotatably mounted on the housing via a passage opening disposed in the first housing wall and a recess disposed in the second housing wall, the second housing wall disposed opposite the first housing wall with respect to the rotation axis;
• the passage opening of the first housing wall delimited circumferentially to the rotation axis by a wall section of the first housing wall, wherein the actuating shaft supports itself within the passage opening directly on the first housing wall;
• the recess of the second housing wall provided with a passage opening including a first axial section having a first opening diameter facing the housing interior that extends into a second axial section of the passage opening of the recess in a direction away from the housing interior, the second axial section having a second opening diameter that is smaller than the first opening diameter, wherein the actuating shaft includes an axial end section received in the first axial section and is supported within the recess directly on the second housing wall of the housing;
• and
• a preload element disposed in the second axial section for preloading the actuating shaft against the first housing wall, wherein the preload element is arranged between a face end of the actuating shaft facing the second housing wall and a housing wall of at least one of a compressor housing and a turbine housing, the at least one of the compressor housing and the turbine housing mountable against a side of the second housing wall facing away from the housing interior.

At least one of a variable turbine geometry and a variable compressor geometry for an exhaust gas turbocharger, comprising:

• a housing including a first housing wall and a second housing wall disposed opposite the first housing wall that at least partially define a housing interior, the first housing wall including a passage opening extending therethrough and the second housing wall including a recess aligned with the passage opening;
• a blade bearing ring including at least one guide blade rotatably mounted thereon;
• a control lever for adjusting the at least one guide blade between a closing position and an opening position;
• an actuating shaft having a rotation axis rotatably mounted on the housing and connected to the control lever in a rotationally fixed manner, the actuating shaft arranged in the passage opening of the first housing wall and including an axial end section arranged in the recess, wherein the actuating shaft directly supports itself on the first housing wall in the passage opening and on the second housing wall in the recess;
• a preload element for preloading the actuating shaft;
• wherein the recess of the second housing wall includes a passage opening, the passage opening of the recess including a first axial section having a first opening diameter facing the housing interior and a second axial section disposed away from the housing interior in relation to the first axial section, the second axial section having a second opening diameter that is smaller than the first opening diameter;
• wherein the axial end section of the actuating shaft is disposed in the first axial section;
• and
• wherein the preload element is disposed in the second axial section for preloading the actuating shaft against the first housing wall, the preload element arranged between a face end of the actuating shaft facing the second housing wall and a housing wall of at least one of a compressor housing and a turbine housing that is mountable against a side of the second housing wall facing away from the housing interior.