Turbocharger with variable-nozzle cartridge, including resilient heat shield assembly to locate the cartridge axially

Patent metadata

Field	Value
Publication number	US-10927698-B2
Application number	US-201916245222-A
Country	US
Kind code	B2
Filing date	Jan 10, 2019
Priority date	Jan 10, 2019
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

A turbocharger includes a variable-nozzle cartridge having a nozzle ring that supports an array of variable vanes in the turbine nozzle. A heat shroud and spring assembly is disposed in a space bounded between the turbine wheel, the nozzle ring, and the center bearing housing of the turbocharger. The heat shroud and spring assembly includes discretely formed heat shroud and spring components configured as annular non-planar disk-shaped parts. The heat shroud and spring are in contact with each other at their radially inner and radially outer peripheral regions, but are spaced apart between those peripheral regions, thereby creating a sealed-off dead space between them. The dead space can significantly reduce the maximum temperature of the spring, relative to arrangements having a single shroud or having dual shrouds with no dead space between them.

First claim

What is claimed is:

1. A turbocharger having a variable-nozzle turbine, comprising:
a turbine assembly comprising a turbine housing and a turbine wheel mounted in the turbine housing and connected to a rotatable shaft for rotation therewith, the turbine housing defining a chamber for receiving exhaust gas and for supplying the exhaust gas to the turbine wheel, the turbine assembly defining a nozzle leading from the chamber radially inwardly to the turbine wheel;
a compressor assembly comprising a compressor housing and a compressor wheel mounted in the compressor housing and connected to the rotatable shaft for rotation therewith; a center housing connected between the compressor housing and the turbine housing, the center housing defining a radial reference surface that faces radially outwardly and an axial reference surface that faces axially toward the turbine wheel;
a variable-nozzle cartridge connected between the center housing and the turbine housing and comprising an assembly of an annular nozzle ring and an array of rotatable vanes circumferentially spaced about the nozzle ring and disposed in the nozzle for regulating exhaust gas flow to the turbine wheel, wherein the nozzle ring at a radially inner periphery thereof defines a radial reference surface that faces radially inwardly and opposes the radial reference surface of the center housing, and an axial reference surface that faces axially away from the turbine wheel;
an insert defining a nozzle portion that is axially spaced from the nozzle ring such that the vanes extend between the nozzle ring and the nozzle portion, a plurality of spacers being connected between the nozzle ring and the nozzle portion of the insert; and
a heat shroud and spring assembly disposed in a space bounded between the radially inner periphery of the nozzle ring, the turbine wheel, and the center housing, the heat shroud and spring assembly comprising a heat shroud and a spring formed as two discrete parts, the heat shroud comprising an annular non-flat disk-shaped part and the spring comprising an annular non-flat disk-shaped part, the heat shroud and the spring abutting each other at radially outer and radially inner peripheral regions thereof and being spaced apart over an intermediate region between said radially inner and radially outer peripheral regions so as to define a dead space between the heat shroud and the spring that is sealed off from exhaust gases surrounding the heat shroud and spring assembly.

2. The turbocharger of claim 1 , wherein the heat shroud at the radially outer peripheral region thereof is in contact with the axial reference surface of the nozzle ring, and the spring at the radially inner peripheral region thereof is in contact with the axial reference surface of the center housing, and wherein the heat shroud and spring assembly is axially compressed between the axial reference surface of the nozzle ring and the axial reference surface of the center housing so as to axially locate the nozzle ring relative to the center housing.

3. The turbocharger of claim 2 , further comprising a locator disposed between and in contact with the radial reference surface of the nozzle ring and the radial reference surface of the center housing so as to radially locate the nozzle ring relative to the center housing.

4. The turbocharger of claim 1 , wherein the heat shroud is constructed of a first material and the spring is constructed of a second material that differs from the first material.

5. The turbocharger of claim 1 , wherein the turbine housing defines an axial bore through which exhaust gas is discharged from the turbine wheel, and the insert further comprises a tubular portion received into the axial bore of the turbine housing, the nozzle portion extending radially out from one end of the tubular portion.

6. The turbocharger of claim 1 , wherein the radially outer peripheral region of the heat shroud extends radially inwardly to a first bend, at which the heat shroud angles radially inwardly and axially toward the turbine wheel to a second bend, at which the heat shroud bends to extend substantially radially inwardly to a third bend, at which the heat shroud angles radially inwardly and axially toward the center housing.

7. The turbocharger of claim 6 , wherein the spring is closer to being planar than the heat shroud, thereby creating the dead space between the spring and the heat shroud.

Assignees

• Garrett Transportation I Inc

Inventors

• Micanek Vit
• Protiva Miroslav
• Kovarova Lucie

Classifications

• F01D25/08

  Cooling (of machines or engines in general F01P); Heating; Heat-insulation (of blade-carrying members, of blades F01D5/00) · CPC title

• F04D29/08

  Sealings · CPC title

• F02C6/12

  Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure · CPC title

• F05D2260/231

  Preventing heat transfer · CPC title

• F05D2220/40

  in turbochargers · CPC title