Variable geometry turbocharger

Patent metadata

Field	Value
Publication number	US-11028767-B2
Application number	US-201616087907-A
Country	US
Kind code	B2
Filing date	Mar 28, 2016
Priority date	Mar 28, 2016
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A variable geometry turbocharger (100) includes a bearing housing (10) including a bearing-housing side support portion (40) configured to support a radially outer portion (38) of a nozzle mount (16) from a side opposite to a scroll flow passage (4) in an axial direction of a turbine rotor (2), and wherein at least one of the following condition (a) or (b) is satisfied: (a) the bearing-housing side support portion (40) includes at least one bearing-housing side recess portion (46) formed so as to be recessed in the axial direction so as not to be in contact with the radially outer portion (38); (b) the radially outer portion (38) of the nozzle mount (16) includes at least one nozzle-mount side recess portion (62) formed so as to be recessed in the axial direction so as not to be in contact with the bearing-housing side support portion (40).

First claim

The invention claimed is:

1. A variable geometry turbocharger, comprising:
a turbine rotor;
a turbine housing which accommodates the turbine rotor and which forms a scroll flow passage on a radially outer side of the turbine rotor;
a bearing housing accommodating a bearing which rotatably supports the turbine rotor, the bearing housing being coupled to the turbine housing; and
a variable nozzle mechanism for adjusting a flow of exhaust gas to the turbine rotor from the scroll flow passage,
wherein the variable nozzle mechanism includes:
a nozzle vane disposed in an exhaust gas flow passage for guiding the exhaust gas from the scroll flow passage to the turbine rotor;
a nozzle mount having an annular shape and supporting the nozzle vane rotatably, the nozzle mount forming a flow passage wall on a bearing-housing side of the exhaust gas flow passage; and
a nozzle plate having an annular shape and being disposed so as to face the nozzle mount, the nozzle plate forming a flow passage wall, of the exhaust gas flow passage,

a plurality of bolts disposed at intervals in a circumferential direction of the turbine rotor and configured to fasten the turbine housing and the bearing housing in the axial direction,
wherein the bearing housing includes a bearing-housing side support portion configured to support a radially outer portion of the nozzle mount from a side opposite to the scroll flow passage in an axial direction of the turbine rotor,
wherein the bearing-housing side support portion includes at least one bearing-housing side recess portion formed so as to be recessed toward a side opposite to the nozzle mount in the axial direction,
wherein the at least one bearing-housing side recess portion includes a plurality of bearing-housing side recess portions disposed at intervals in a circumferential direction of the turbine rotor, and
wherein the bearing-housing side recess portion is formed in an angular range which does not overlap with a center position of a bolt adjacent to the bearing-housing side recess portion, of the plurality of bolts, in the circumferential direction.

2. The variable geometry turbocharger according to claim 1 ,
wherein the bearing-housing side recess portion is formed to be 5 degrees or more apart from the center position of the bolt adjacent to the bearing-housing side recess portion, of the plurality of bolts, in the circumferential direction.

3. The variable geometry turbocharger according to claim 1 ,
wherein the turbine housing includes a turbine-housing side support portion configured to support the radially outer portion of the nozzle mount from a side opposite to the bearing-housing side support portion in the axial direction,
wherein the nozzle mount is nipped by the turbine-housing side support portion and the bearing-housing side support portion, and
wherein the turbine-housing side support portion is disposed so as to protrude toward an inner side of the bearing-housing side support portion in a radial direction of the turbine rotor, along a surface of the nozzle mount.

4. The variable geometry turbocharger according to claim 3 ,
wherein the turbine-housing side support portion includes a contact portion to be in contact with the radially outer portion of the nozzle mount, and a non-contact portion formed on an inner side of the contact portion in the radial direction, the non-contact portion facing the nozzle mount via a gap.

5. The variable geometry turbocharger according to claim 3 ,
wherein an expression 0≤(r1-r3)/(r2-r3)≤0.75 is satisfied, where r1 is a distance between a radially inner end of the turbine-housing side support portion and a rotational axis of the turbine rotor, r2 is a distance between a radially outer end of the nozzle mount and the rotational axis, and r3 is a distance between a radially outer end of the nozzle plate and the rotational axis.

6. The variable geometry turbocharger according to claim 5 ,
wherein an expression 0≤(r1-r3)/(r2-r3)≤0.30 is satisfied.

7. The variable geometry turbocharger according to claim 1 , further comprising:
a heat shield member disposed between the bearing-housing side support portion and the nozzle mount.

8. The variable geometry turbocharger according to claim 7 ,
wherein the heat shield member has a lower thermal conductivity than each of a thermal conductivity of the bearing housing and a thermal conductivity of the nozzle mount.

9. The variable geometry turbocharger according to claim 7 ,
wherein the heat shield member is formed of austenitic stainless steel or nickel-based alloy.

10. The variable geometry turbocharger according to claim 7 ,
wherein the heat shield member comprises a ring-shaped heat-shield plate disposed so that the bearing-housing side support portion and the nozzle mount do not make contact with each other over an entire angular range in a circumferential direction of the turbine rotor.

11. The variable geometry turbocharger according to claim 7 ,
wherein the heat shield member comprises a coating applied to the radially outer portion of the bearing-housing side support portion or the nozzle mount.

Assignees

• Mitsubishi Heavy Ind Engine & Turbocharger Ltd

Inventors

• Sakamoto Keigo
• Dammoto Yosuke
• Katou Eigo
• Akiyama Yoji
• Seike Nariaki
• Yoshida Toyotaka
• Chiba Takeru

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02B37/24 Primary

  by using pumps or turbines with adjustable guide vanes · CPC title

• F02B37/186

  Arrangements of actuators or linkage for bypass valves · CPC title

• F04D27/002

  by varying geometry within the pumps, e.g. by adjusting vanes · CPC title

• F01D17/165

  for radial flow, i.e. the vanes turning around axes which are essentially parallel to the rotor centre line (F01D17/167 takes precedence) · CPC title