Turbocharger with sliding blades having combined dynamic surfaces and heat screen and uncoupled axial actuating device

• US 6,694,733 B1
• Filed: 11/05/2002
• Issued: 02/24/2004
• Est. Priority Date: 01/14/2000
• Status: Expired due to Term

• Current Assignee: Garrett Transportation I Inc. (Garrett Motion, Inc.)
• Original Assignee: Honeywell Garrett SA (Honeywell International Inc.)
• Inventors: Perrin, Jean-Luc Hubert, Lombard, Alain Rene, Bernardini, Luciano Labindo, Viola, Eric Joseph
• Primary Examiner(s): Richter, Sheldon J.
• Application Number:
  US10/181,224
• Time in Patent Office: 476 Days
• Field of Search: 606/02, 415/157, 415/158, 417/407
• US Class Current: 60/602
• CPC Class Codes: F01D 17/167 of vanes moving in translation
• CPC Class Codes: F02B 37/24 by using pumps or turbines with adjustable guide vanes
• CPC Class Codes: F02C 6/12 Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure
• CPC Class Codes: F05D 2220/40 in turbochargers

Abstract

A turbocharger having a variable geometry turbine intake incorporating a mobile cylindrical piston (70) for varying the area of the induction nozzle in the turbine (18). Blades (90) mounted on the piston for controlling the flow in the nozzle penetrate through a slotted heat shield (92) having a central opening wherein the rear disc of the turbine wheel is embedded to provide a smooth aerodynamic flow in the turbine vanes. A shield (100) engaged between the heat screen and a central housing of the turbocharger prevents the gas from the rear disc cavity from recycling into the cavity housing the blades further enhancing the aerodynamic flow. An axial actuating device (77) is secured for operating the piston via a shaft coupled by a cross (72) to the piston and coupled to an actuating hub (118) in the actuating device by quick connect unthreaded connection (122).

Claims

1. A turbocharger (10) comprising:

a casing having a turbine housing (12) receiving exhaust gas from an exhaust head of an internal combustion engine at an intake and having an exhaust outlet, a compressor housing (16) having an air intake and a first volute, and a central housing (14) between the turbine housing (12) and the compressor housing (16);

a turbine wheel (18) mounted in the turbine housing (12) and extracting the energy from the exhaust gas, the said turbine wheel (18) connected to a shaft (20) extending from the turbine housing (12) through a shaft bore (52) in the central housing (14) and the said turbine wheel (18) having a rear disc and multiple vanes;

a bearing (50) mounted in the shaft bore (52) of the central housing (14), the said bearing supporting the shaft (20) for rotational movement;

a vane wheel (22) connected to the said shaft (20) facing the turbine wheel (18) and enclosed in the compressor housing (16);

a substantially cylindrical piston (70), concentric to the turbine wheel (18) and able to be displaced parallel to an axis of rotation of the turbine wheel (18);

a plurality of blades (90) extending substantially parallel to the axis of rotation from a first end of the piston in the proximity of the rear disc;

a heat screen (92) engaged at its external circumference between the turbine housing (12) and the central housing (14) and extending radially inwards towards the axis of rotation, the rear disc of the turbine wheel housed in the heat screen (92) for the smooth flow of the exhaust gas in the vanes, the said heat screen (92) also having a plurality of slots (96) receiving the blades (90); and

means (77) for displacing the piston (70) from a first position in which the first end is in the proximity of the heat screen to a second position in which the first end is remote from the heat screen,

further characterised by;

an aerodynamic shield (100) located between the rear disc of the turbine wheel (18) and the central housing (14) and having an external circumferential portion engaging an internal circumferential portion of the heat screen (100), the said aerodynamic shield having an internal circumferential portion engaging the central housing (14) in the proximity of the shaft bore.

2. Turbocharger as defined in claim 1, wherein the heat screen (92) has a central orifice in which the rear disc is embedded and wherein the plurality of slots in the heat screen (92) each have a closed rear edge in the proximity of the central orifice.

3. Turbocharger as defined in claim 1, wherein the heat screen (92) has a central orifice in which the rear disc is embedded and wherein the plurality of slots of the heat screen (92) each have a profile extending beyond an external surface of the associated blade substantially as far as the diameter of the central orifice, the said profile extending along an internal surface of the associated blade ending at the central orifice leaving an orifice at the rear edge connecting to the central orifice.

4. Turbocharger as defined in claim 1, wherein the means for displacing the piston comprise;

a cross-piece (72) having a plurality of branches attached to the piston, the said branches converging towards an actuating shaft concentric to the axis of rotation;

an actuating device (77) having an actuating hub (118); and

a quick-connect connection means (122) to connect the actuating shaft and the actuating hub.

5. Turbocharger as defined in claim 4, wherein the actuating device is a pneumatic actuating device having a diaphragm connected to the actuating hub (118).

6. Turbocharger as defined in claim 4, wherein the quick-connect connection means has a cylinder made of sheet metal having a longitudinal slot (140) and at least one pair of elastic tongues (144) spaced apart in an opposite longitudinal orientation along the cylinder and extending into it, one of the pair of tongues being adapted to engage a circumferential slot (146) in the actuating shaft and the second of the pair of tongues being adapted to engage a circumferential slot (148) in the actuating hub (118).

7. Turbocharger as defined in claim 6, wherein the actuating hub (118) includes a counter bore (126) adapted to receive, in a close-fitting manner, an alignment connection (124) extending from the actuating shaft.