Adjustable nozzle mechanism for variable capacity turbine and its production method

• US 6,736,595 B2
• Filed: 02/25/2002
• Issued: 05/18/2004
• Est. Priority Date: 02/27/2001
• Status: Expired due to Term

• Current Assignee: Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Sakamoto, Taro, Jinnai, Yasuaki
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): MCALEENAN, JAMES M
• Application Number:
  US10/080,661
• Publication Number:
  US 20020119039A1
• Time in Patent Office: 813 Days
• Field of Search: 415/164, 415/163, 415/165, 415/166, 415/158, 415/157, 415/150, 415/148, 415/219.R, 606/02, 298/892.2, 298/892.1
• US Class Current: 415/164
• 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: Y10T 29/49323 Assembling fluid flow directing devices, e.g., stators, diaphragms, nozzles

Abstract

A variable capacity turbine has adjustment work simplified so as to decrease man-hours, assembly and adjustment costs. The structure is simplified to decrease part category numbers and the number of parts itself, decreasing part costs and enabling nozzle vane setup to a high degree of accuracy without being influenced by the degree of dimensional accuracy of the component parts. A plurality of joint members (lever plates) are used which are the same in number as the nozzle shafts to connect a plurality of nozzle vanes and the nozzle driving member. Each nozzle shaft is fitted and fixed to one end of a respective lever plate after setting the predetermined positional relationship between the wing angle of the nozzle vanes and the predetermined fitting direction of the fixed section of the lever plate. Another end of each lever plate is engaged with the nozzle driving member.

Claims

1. An assembling method to assemble an adjustable nozzle mechanism used in a variable capacity turbine, wherein the variable capacity turbine comprises:

a plurality of nozzle of vanes arranged along a turbine circumference and provided on nozzle shafts supported on a turbine casing so that the nozzle vanes can rotate and vary their vane angle;

a nozzle driving member for driving the nozzle vanes, the nozzle driving member being rotatable around an axis of the turbine by an actuator; and

a turbine rotor that is free to rotate at a position radially inside of the nozzle vanes so that actuating gas flowing from a scroll in the turbine casing and through the nozzle vanes can rotatably drive the turbine rotor;

said method comprising;

fitting and fixing each of the nozzle shafts to one end of respective lever plates after a predetermined positional relationship between the wing angle of the nozzle vanes and a predetermined fitting direction of a fixing section of the lever plates has been set, wherein a coupling hole at the one end of the lever plates and a coupling shaft at an end of the respective nozzle shafts have a geometric relationship prior to said fitting and fixing such that the wing angle and a rotating angle of a link plate of the nozzle driving member are in the predetermined positional relationship after said fitting and fixing; and

engaging an other end of each of the lever plates with the link plate of the nozzle driving member.

2. The method of claim 1, wherein said fitting and fixing comprises:

forming the coupling hole in each of the lever plates by creating a non-circular hole having a stopper surface by making two opposite surfaces of the hole parallel, by forming the hole with an oblong shape or by forming the hole with a curved surface on one side wall;

forming a notched coupling shaft having a fitting surface on an end of each of the nozzle shafts, the fitting surfaces having a shape corresponding to the coupling hole of the lever plates for functioning as a stopper;

fitting the coupling shafts into the coupling holes without causing plastic deformation of the coupling shafts or coupling holes and engaging the stopper surface of the coupling holes with the matching fitting surfaces of the notched coupling shafts so that the lever plates and the nozzle shafts cannot rotate relative to each other because of the stopper surfaces and fitting surfaces functioning as stoppers; and

processing the nozzle shafts and the lever plates using a chamfered portion of the lever plates having a larger diameter than the notched coupling shafts so as to prevent the nozzle shafts from coming out of the coupling holes and de-coupling from the lever plates.

3. The method of claim 2, wherein said processing comprises punching an end portion of the notched coupling shafts after said engaging the stopper surface of the coupling holes with the matching fitting surfaces of the notched coupling shafts such that the end portion of the notched coupling shafts engages with the chamfered portion of the lever plates and prevents the nozzle shafts from coming out of the coupling holes and de-coupling from the lever plates.

4. The method of claim 1, wherein said engaging comprises fitting slots of the lever plates with respective fitting pins of the driving member, the fitting pins being equal in number to the lever plates, the fitting pins protruding from the nozzle driving member and spaced in a circumferential direction thereof, and the slots being open in a nearly radial direction at the other end of the lever plates to engage with the fitting pins.

5. An adjustable nozzle mechanism used in a variable capacity turbine, wherein the variable capacity turbine comprises:

a plurality of nozzle of vanes arranged along a turbine circumference and provided on nozzle shafts supported on a turbine casing so that the nozzle vanes can rotate and vary their vane angle;

a nozzle driving member for driving the nozzle vanes, the nozzle driving member being rotatable around an axis of the turbine by an actuator having a link plate; and

a turbine rotor that is free to rotate at a position radially inside of the nozzle vanes so that actuating gas flowing from a scroll in the turbine casing and through the nozzle vanes can rotatably drive the turbine rotor;

said adjustable nozzle mechanism comprising;

a plurality of lever plates provided between the nozzle vanes and the link plate, wherein one end of each of said lever plates has been fitted and fixed to a respective one of the nozzle shafts after a predetermined positional relationship between the wing angle of the nozzle vanes and a predetermined fitting direction of a fixing section of said lever plates has been set;

a coupling hole at the one end of said lever plates and a coupling shaft at an end of the respective nozzle shafts having a geometric relationship that sets the wing angle and a rotating angle of the link plate of the nozzle driving member in the predetermined positional relationship; and

a slot in each of said lever plates being radially outwardly open at the other end of the lever plates and engaging with respective fitting pins on the link plate;

wherein the fitting pins are equal in number to the lever plates, protrude from the nozzle driving member and are spaced in a circumferential direction thereof.

6. The mechanism of claim 5, wherein the coupling hole and the coupling shaft are non-circular.