Transmission system and exhaust gas turbocharger

A transmission system for an adjusting device of a waste gate of an exhaust gas turbocharger, comprising:

• a three-part linkage mechanism, which has a driver arm that is operatively connected to a drive via a transmission, an output arm and a coupler, which operatively connects the driver arm and the output arm;
• wherein the transmission has a driving gear, assigned to the drive, and a driven gear, which is assigned to the driver arm and interacts with the driving gear;
• wherein the driving gear has a rolling curve radius, which changes over the circumference, and the driven gear has a rolling curve radius that runs complementary to the former;
• wherein the rolling curve radii are selected in an angle of rotation range about the extended position of the three-part linkage mechanism to form at least in a first region a first transmission ratio and outside the angle of rotation range to form at least in a second region a second transmission ratio that is larger than the first transmission ratio;
• wherein the driver arm and the driven gear are one piece, and
• wherein a third transmission ratio is provided outside the angle of rotation range in a third region such that the second region is situated between the first region and the third region, the third transmission ratio being smaller than the second transmission ratio.

An exhaust gas turbocharger, comprising:

• a waste gate;
• an adjusting device for adjusting the waste gate, the adjusting device having a transmission system, with a three-part linkage mechanism having a driver arm that is operatively connected to a drive by a transmission, an output arm and a coupler, which operatively connects the driver arm and the output arm, the transmission having a driving gear, assigned to the drive, and a driven gear, which is assigned to the driver arm and interacts with the driving gear;
• wherein the driving gear has a rolling curve radius, which changes over the circumference;
• wherein the driven gear has a rolling curve radius that runs complementary to the former;
• wherein the rolling curve radii are selected in an angle of rotation range about the extended position of the three-part linkage mechanism to form at least in a first region a first transmission ratio and outside the angle of rotation range to form at least in a second region one second transmission ratio that is larger than the first transmission ratio;
• wherein the driver arm is connected in a rotationally rigid manner to the driven gear and is mounted with the driven gear in a common bearing, and
• wherein a third transmission ratio is provided outside the angle of rotation range in a third region such that the second region is situated between the first region and the third region, the third transmission ratio being smaller than the second transmission ratio.