Turbocharger, and a method for manufacturing a turbocharger
A turbocharger having a swing vane nozzle assembly—VGT—is provided. The turbocharger includes a turbine housing and a bearing housing. The swing vane nozzle assembly includes a front nozzle ring, a rear nozzle ring, and a plurality of pivotable gas flow control vanes arranged between the front nozzle ring and the rear nozzle ring. The rear nozzle ring is radially guided by the turbine housing, a radially outer portion of the front nozzle ring is clamped between the bearing housing and the turbine housing thus forming an axial guidance of the front nozzle ring, and an inner periphery of the front nozzle ring is arranged at a distance from the bearing housing.
1. A turbocharger having a swing vane nozzle assembly, the turbocharger comprising
a turbine housing and a bearing housing, and wherein the swing vane nozzle assembly is configured to control an exhaust gas flow to a turbine arranged inside the turbine housing, the swing vane nozzle assembly comprising
a front nozzle ring, a rear nozzle ring, and a plurality of pivotable gas flow control vanes arranged between the front nozzle ring and the rear nozzle ring, wherein
wherein the front nozzle ring radially encircles the turbine;
the rear nozzle ring is radially guided by the turbine housing,
a radially outer portion of the front nozzle ring is clamped between the bearing housing and the turbine housing thus forming an axial guidance of the front nozzle ring;
a radial gap arranged between an inner periphery of the front nozzle ring and a closest portion of the bearing housing, and
wherein an interface between the bearing housing and the turbine housing forms a recess in which the radially outer portion of the front nozzle ring is received, and the turbine housing has a cylindrical portion arranged radially outside the turbine, and outer periphery of the cylindrical portion forming a supporting surface for the rear nozzle ring.
2. The turbocharger according to claim 1 , further comprising a heat shield arranged between the bearing housing and the inner periphery of the front nozzle ring.
3. The turbocharger according to claim 2 , wherein the heat shield has an annular shape having a radially inner portion and a radially outer portion, the outer portion being axially displaced relative the inner portion.
4. The turbocharger according to claim 3 , wherein the outer portion of the heat shield is axially displaced in a direction towards a turbine arranged inside the turbine housing.
5. The turbocharger according to claim 3 , wherein the outer portion of the heat shield seals against the front nozzle ring.
6. The turbocharger according to claim 1 , wherein the width of the recess is slightly larger than the width of radially outer portion of the front nozzle ring such that the axial guidance is formed by a light clearance fit.
7. The turbocharger according to claim 1 , further comprising a spring arranged between the bearing housing and the radially outer portion of the front nozzle ring.
8. The turbocharger according to claim 7 , wherein the spring is a plate spring.
9. The turbocharger according to claim 1 , further comprising a seal arranged between the turbine housing and the inner periphery of the rear nozzle ring.
10. The turbocharger according to claim 9 , wherein the seal is an O-ring.
11. An exhaust aftertreatment system for an internal combustion engine comprising at least one turbocharger according to claim 1 .
12. A vehicle comprising an exhaust aftertreatment system according to claim 11 .
13. A method for manufacturing a turbocharger with a swing vane nozzle assembly having a front nozzle ring, a rear nozzle ring, and a plurality of pivotable gas flow control vanes arranged between the front nozzle ring and the rear nozzle ring, comprising:
arranging the rear nozzle ring onto a cylindrical portion of a turbine housing such that the rear nozzle ring is radially guided by the turbine housing, the cylindrical portion being arranged radially outside the turbine,
arranging a radially outer portion of the front nozzle ring between a bearing housing and the turbine housing thus forming an axial guidance of the front nozzle ring, an interface between the bearing housing and the turbine housing forming a recess in which a radially outer portion of the front nozzle ring is received, and
arranging a radial gap between an inner periphery of the front nozzle ring and a closest portion of the bearing housing,
wherein the outer periphery of the cylindrical portion forms a supporting surface for the rear nozzle ring.
14. The method according to claim 13 , further comprising providing a heat shield between the bearing housing and the inner periphery of the front nozzle ring.
15. The method according to claim 14 , wherein providing the heat shield is performed such that the outer portion of the heat shield seals against the front nozzle ring.
16. The method according to claim 14 , wherein arranging the rear nozzle ring onto a cylindrical portion of a turbine housing and arranging a radially outer portion of the front nozzle ring between a bearing housing and the turbine housing are performed by positioning the swing vane nozzle assembly in the bearing housing, and thereafter arranging the turbine housing in the correct position relative the bearing housing, and wherein arranging the heat shield is performed before the step of positioning the swing vane nozzle assembly in the bearing housing.
17. The method according to claim 13 , further comprising arranging a spring between the bearing housing and the radially outer portion of the front nozzle ring.
18. The method according to claim 13 , further comprising arranging a seal between the turbine housing and the inner periphery of the rear nozzle ring.
19. The method according to claim 13 , wherein arranging the rear nozzle ring onto a cylindrical portion of a turbine housing and arranging a radially outer portion of the front nozzle ring between a bearing housing and the turbine housing are performed by positioning the swing vane nozzle assembly in the bearing housing, and thereafter arranging the turbine housing in the correct position relative the bearing housing.