Wastegate arrangement for an exhaust gas turbocharger

A wastegate arrangement for an exhaust gas turbocharger, comprising:

• a turbine housing including a cylindrical bore and a pressure surface at least partially surrounding the cylindrical bore and offset by an axial distance along an axis of the cylindrical bore from an outer end of the cylindrical bore;
• a shaft received in the cylindrical bore, the shaft including a first shaft end disposed within the turbine housing and a second shaft end extending outside of the turbine housing;
• a wastegate flap connected to the first shaft end within the turbine housing, the wastegate flap being configured to be moved between a closed position wherein the wastegate flap closes a wastegate passage of the turbine housing and an open position wherein the wastegate passage is open;
• an actuating lever attached to the second shaft end outside of the turbine housing, the actuating lever including a support surface facing the turbine housing;
• and
• a spring disposed at least partially around the shaft, the spring being received between the support surface of the actuating lever and the pressure surface of the turbine housing so that the spring exerts a spring pressure on the pressure surface to generate a spring preload between the turbine housing and the support surface of the actuating lever;
• wherein the spring includes first and second spring rings each having alternating elevations and depressions distributed along a circumference of the spring ring and facing an axial end of the spring;
• and
• wherein the spring includes first and second support rings ring disposed in planes extending parallel to the pressure surface and the support surface, the first spring ring being bent from the first support ring and the second spring ring being bent from the first spring ring and the second support ring so that the first and second support rings and the first and second spring rings are all integrally formed.

A wastegate arrangement for an exhaust gas turbocharger, comprising:

• a turbine housing including a cylindrical bore and a pressure surface at least partially surrounding the cylindrical bore and offset by an axial distance along an axis of the cylindrical bore from an outer end of the cylindrical bore;
• a shaft received in the cylindrical bore, the shaft including a first shaft end disposed within the turbine housing and a second shaft end extending outside of the turbine housing;
• a wastegate flap connected to the first shaft end within the turbine housing, the wastegate flap being configured to be moved between a closed position wherein the wastegate flap closes a wastegate passage of the turbine housing and an open position wherein the wastegate passage is open;
• an actuating lever attached to the second shaft end outside of the turbine housing, the actuating lever including a support surface facing the turbine housing;
• and
• a spring disposed at least partially around the shaft, the spring being received between the support surface of the actuating lever and the pressure surface of the turbine housing so that the spring exerts a spring pressure on the pressure surface to generate a spring preload between the turbine housing and the support surface of the actuating lever;
• wherein the spring is an annular spring having a slot in a circumferential direction to permit the spring to be pushed onto the shaft in a radial direction.