Method of reducing turbine wheel high cycle fatigue in sector-divided dual volute turbochargers

• US 10,465,522 B1
• Filed: 10/23/2018
• Issued: 11/05/2019
• Est. Priority Date: 10/23/2018
• Status: Active Grant

• Current Assignee: BorgWarner Incorporated
• Original Assignee: BorgWarner Incorporated
• Inventors: Colley, Matthew Carson, Colont, Craig Andrew, DePaoli, Dominic William, Hastings, Sean
• Primary Examiner(s): Seabe, Justin D
• Assistant Examiner(s): Brown, Adam W
• Application Number:
  US16/168,684
• Time in Patent Office: 378 Days
• CPC Class Codes: F01D 5/048 Form or construction
• CPC Class Codes: F01D 5/16 for counteracting blade vibration
• CPC Class Codes: F01D 9/026 Scrolls for radial machines or engines
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02B 39/00 Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00
• 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
• CPC Class Codes: F05D 2260/83 Testing, e.g. methods, components or tools therefor
• CPC Class Codes: F05D 2260/94 Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF]
• CPC Class Codes: F05D 2300/501 Elasticity
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

High cycle fatigue (HCF) in a turbine wheel of a sector-divided dual volute turbocharger, particularly a turbocharger where the tongue-to-blade gap is as small as from 1-3% of the wheel diameter, is reduced using a turbine wheel with (blade stiffness/backwall stiffness×100) between 41 and 44.

Claims

1. A turbine of an exhaust-gas turbocharger, comprising:

a sector-divided dual volute turbine housing (4) comprising first and second spiral-shaped exhaust-gas channels (5, 6) narrowing circumferentially inwardly, delimited radially to the outside by an inner surface of the turbine housing (4) and separated from each other by first and second tongues (16, 17), each tongue associated with one exhaust-gas channel,

a turbine wheel (2) mounted to be rotatable about an axis of rotation within the turbine housing (4) and comprising a hub having a wheel backwall (21) which is of closed configuration as viewed from an axial direction and which has a circular circumference, a hub which extends from the wheel backwall and which tapers along the axial direction, and a multiplicity of turbine blades (20) which extend from the wheel backwall (21) and from the hub and which extend radially outward,

wherein each of said multiplicity of turbine blades (20) has a stiffness, wherein the backwall (21) has a stiffness, and wherein a stiffness ratio (blade stiffness/backwall stiffness×

100) is from 41 to 44.

2. The turbine of claim 1, wherein the stiffness ratio is from 41.2 to 43.5.

3. The turbine of claim 1, wherein the stiffness ratio is from 41.5 and 43.3.

4. The turbine of claim 1, wherein a gap is provided between the tongues (16, 17) and passing turbine blades (20), wherein the gap is from 1-7% of the wheel diameter.

5. The turbine of claim 1, wherein a gap is provided between the first and second tongues (16, 17) and passing turbine blades (20), wherein the gap is from 1-3% of the wheel diameter.

6. The turbine of claim 1, wherein a gap is provided between the tongues (16, 17) and passing turbine blades (20), wherein the gap is from 1-2% of the wheel diameter.

7. An exhaust gas turbocharging system (1) comprising

a first exhaust manifold (9) and a second exhaust manifold (10),

a pressure-charged combustion engine (8) having at least one cylinder head comprising at least two cylinders (C₁, C₂), in which each cylinder has at least one outlet port for discharging the exhaust gases from the cylinder, wherein at least two cylinders are configured in such a way that they form first and second cylinder groups, each cylinder group comprising at least one cylinder, the first group supplying exhaust to said first exhaust manifold (9) and the second cylinder group supplying exhaust gas to said second exhaust manifold (10),

a sector-divided dual volute turbine housing (4) comprising first and second spiral-shaped exhaust-gas channels (5, 6) narrowing circumferentially inwardly, delimited radially to the outside by an inner surface of the turbine housing (4) and separated from each other by first and second tongues (16, 17), each tongue associated with one exhaust-gas channel (5, 6), the first spiral-shaped exhaust-gas channel (5) receiving exhaust flow from the first exhaust manifold (9) and the second spiral-shaped exhaust-gas channel (5) receiving exhaust flow from the second exhaust manifold (10),

a turbine wheel (2) mounted to be rotatable within the turbine housing (4) comprising a hub having a wheel backwall (21) which is of closed configuration as viewed from an axial direction and which has a circular circumference, a hub which extends from the wheel backwall and which tapers along the axial direction, and a multiplicity of turbine blades (20) which extend from the wheel backwall and from the hub and which extend radially outward,

wherein each blade has a stiffness, wherein the backwall has a stiffness, and wherein stiffness ratio (blade stiffness/backwall stiffness×

100) is from 41 to 44.

8. The exhaust gas turbocharging system of claim 7, wherein the stiffness ratio is from 41.2 to 43.5.

9. The exhaust gas turbocharging system of claim 7, wherein the stiffness ratio is from 41.5 and 43.3.

10. The exhaust gas turbocharging system of claim 7, wherein a gap is provided between the tongues (16, 17) and passing turbine blades (20), wherein the gap is from 1-7% of the wheel diameter.

11. The exhaust gas turbocharging system of claim 7, wherein a gap is provided between the tongues (16, 17) and passing turbine blades (20), wherein the gap is from 1-3% of the wheel diameter.

12. The exhaust gas turbocharging system of claim 7, wherein a gap is provided between the tongues (16, 17) and passing turbine blades (20), wherein the gap is from 1-2% of the wheel diameter.