Variable-throat exhaust turbocharger and method for manufacturing constituent members of variable throat mechanism

• US 7,406,826 B2
• Filed: 08/25/2006
• Issued: 08/05/2008
• Est. Priority Date: 08/25/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Hayashi, Noriyuki, Ibaraki, Seiichi, Jinnai, Yasuaki
• Primary Examiner(s): Denion; Thomas
• Assistant Examiner(s): DAVIS, MARY ALICE
• Application Number:
  US11/509,636
• Publication Number:
  US 20070068155A1
• Time in Patent Office: 711 Days
• Field of Search: 606/02, 415160-166, 298/892
• US Class Current: 60/602
• CPC Class Codes: F01D 17/165 for radial flow, i.e. the vanes turning around axes which are essentially parallel to the rotor centre line F01D17/167 takes precedence
• CPC Class Codes: F05D 2220/40 in turbochargers
• CPC Class Codes: F05D 2230/211 by precision casting, e.g. microfusing or investment casting
• CPC Class Codes: F05D 2230/313 by physical vapour deposition
• CPC Class Codes: F05D 2230/314 by chemical vapour deposition
• CPC Class Codes: F05D 2230/90 Coating; Surface treatment manufacture with deposition of material F05D2230/30
• CPC Class Codes: Y10T 29/4932 Turbomachine making

Abstract

A variable-throat exhaust turbocharger has a variable throat mechanism that reduces wear of contact surfaces of connection pin parts formed integral with lever plates or a drive ring and the grooves into which the connection pin parts are engaged. A mechanism also prevents slipping out of the drive ring from a nozzle mount toward the lever plate to prevent a probable occurrence of failure in action of the variable throat mechanism caused by the slipping out of the drive ring. The connection pin parts connecting between the lever plates and drive ring of the variable throat mechanism are formed integral with either the lever plates or the drive ring by extrusion or by precision casting. At least the connection pin parts or grooves into each of which each of the connection pin parts, is engaged, are treated with surface hardening including diffusion coating.

Claims

1. A variable-throat exhaust turbocharger equipped with a variable throat mechanism comprising a plurality of nozzle vanes supported rotatably by a nozzle mount fixed to a turbine casing, an annular drive ring connected to and rotated by an actuator, and lever plates identical in number with the number of the nozzle vanes, each of the lever plates being connected at one end to the drive ring via a connection pin and a groove into which the connection pin is engaged and at the other end to the nozzle vanes, whereby the lever plates are swung by rotating the drive ring and the nozzle vanes are rotated by the swing of the lever plates to vary the blade angle of the nozzle vanes,

wherein said drive ring is disposed between said lever plates and nozzle mount side by side with the lever plates and nozzle mount in an axial direction thereof, and a plurality of partial circumferential grooves are provided at the outer side part of the nozzle mount, thereby receiving the drive ring in the partial circumferential grooves and preventing the drive ring from moving in the axial direction.

2. A variable-throat exhaust turbocharger equipped with a variable throat mechanism according to claim 1,

wherein a plurality of engaging portions are provided, the engaging portions being composed of convex portions and concave portions provided either to the drive ring or nozzle mount respectively, so that the drive ring is fitted to the nozzle mount by matching the convex portions and concave portions and shifting axially the drive ring relative to the nozzle mount, whereby the drive ring is allowed to be engaged into said partial circumferential grooves by shifting the drive ring in a rotation direction after the drive ring is fitted to the nozzle mount.

3. A variable-throat exhaust turbocharger equipped with a variable throat mechanism comprising:

a nozzle mount fixed to a turbine casing;

a plurality of nozzle vanes rotatably supported by said nozzle mount;

an annular drive ring connected to and rotated by an actuator; and

lever plates identical in number with said nozzle vanes, each of said lever plates being connected at one end of said lever plates to said drive ring via a connection pin and a groove into which the connection pin is engaged and at the other end of said lever plates to respective ones of said nozzle vanes so that said lever plates are swung by rotating said drive ring and said nozzle vanes rotated by the swinging of said plurality of lever plates so as to vary a blade angle of said nozzle vanes;

wherein said drive ring is disposed between said lever plates and said nozzle mount, so as to be side by side with said lever plates and said nozzle mount in an axial direction thereof; and

wherein rivets are fixed to said nozzle mount at an outer side face of said nozzle mount so that an outer side face of said drive ring is in contact with seating faces of said rivets and said rivets prevent said drive ring from moving in the axial direction.

4. The variable-throat exhaust turbocharger equipped with a variable throat mechanism according to claim 3, wherein recesses extend across said outer side face of said drive ring and said outer side face of said nozzle mount, said recesses receiving heads of respective said rivets.

5. A method for manufacturing a variable-throat exhaust turbocharger equipped with a variable throat mechanism comprising a plurality of nozzle vanes rotatably supported by a nozzle mount fixed to a turbine casing, an annular drive ring connected to and rotated by an actuator, and lever plates identical in number with the nozzle vanes, the lever plates being connected at one end to the drive ring via a plurality of connection pins and a plurality of grooves into which the connection pins are engaged and at the other end to the nozzle vanes, whereby the lever plates are swung by rotating the drive ring and the nozzle vanes are rotated by the swinging of the lever plates to vary a blade angle of the nozzle vanes, said method comprising:

disposing the drive ring between the lever plates and the nozzle mount so as to be side by side with the lever plates and the nozzle mount in the axial direction thereof, the nozzle mount having a plurality of partial circumferential grooves at an outer side part thereof, by

fitting the drive ring to the nozzle mount using engaging portions composed of convex portions on one of the drive ring and the nozzle mount and concave portions on the other of the drive ring and the nozzle mount by matching the concave portions and the convex portions and axially shifting the drive ring relative to the nozzle mount, then

rotating the drive ring in a direction of rotation by a certain angle so as to engage the drive ring in the partial circumferential grooves to prevent axial slippage of the drive ring, and

attaching the lever plates to the drive ring and connecting the lever plates with nozzle shafts of the nozzle vanes, the nozzle shafts penetrating the nozzle mount, with the nozzle mount sandwiched between the lever plates and the nozzle vanes.