Turbine arrangement

Abstract

A turbine has a turbine wheel 4, a nozzle ring 34 and an annular spring-retainer 38 with central aperture 40. The turbine wheel is located within a turbine chamber 30 defined by a turbine housing 5 and mounted to a shaft which is supported to rotate about a turbine axis by a bearing. The bearing is located in a bearing housing 3 having an axially extending spigot 32 and attached to the turbine housing. The nozzle ring is received by the turbine housing and includes one or more flow directing vanes 36 in a flow path (F) between an inlet volute 9, defined by part of the turbine housing, and the turbine wheel. The spring-retainer is compressed between the nozzle ring and the bearing housing, the spring-retainer aperture receiving the spigot. An uncompressed axial extent (E) of the spring-retainer is greater than an axial spacing (S) between a back face of the turbine wheel and the spigot. During assembly the spring-retainer is mounted uncompressed onto the upward extending spigot; the bearing housing is then inverted so the spring-retainer contacts the back face of the turbine wheel, urging the nozzle ring away from the bearing housing, against the turbine housing.