Turbocharger with low carbon steel shaft

• US 9,903,225 B2
• Filed: 03/09/2015
• Issued: 02/27/2018
• Est. Priority Date: 03/09/2015
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Annati, Richard E., Knight, Steve, Isenberg, Walter S.
• Primary Examiner(s): MAINES, PATRICK DAVID
• Application Number:
  US14/641,983
• Publication Number:
  US 20160265386A1
• Time in Patent Office: 1,086 Days
• Field of Search: 606051
• CPC Class Codes: F01D 25/005 Selecting particular materials
• CPC Class Codes: F01D 25/16 Arrangement of bearings; Supporting or mounting bearings in casings bearings per se F16C
• CPC Class Codes: F01D 5/025 Fixing blade carrying members on shafts attachment of a member on a shaft in general F16D1/06; for non-positive displacement pumps F04D29/00
• CPC Class Codes: F02B 33/40 of non-positive-displacement type
• 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 39/04 Mechanical drives; Variable-gear-ratio drives non-mechanical pump drives having variable gear ratio F02B39/08
• CPC Class Codes: F02M 35/10157 Supercharged engines
• CPC Class Codes: F04D 25/04 the pump being fluid-driven pumps driven by exhaust gases F02B37/00, F02B39/00; turbochargers F02C6/12
• CPC Class Codes: F04D 29/059 Roller bearings
• CPC Class Codes: F04D 29/063 specially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/102 especially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/266 mounting compressor rotors on shafts
• CPC Class Codes: F04D 29/284 for compressors
• CPC Class Codes: F05D 2220/40 in turbochargers
• CPC Class Codes: F05D 2240/54 Radial bearings
• CPC Class Codes: F05D 2260/80 Diagnostics
• CPC Class Codes: F16C 19/184 in O-arrangement
• CPC Class Codes: F16C 2360/24 Turbochargers in general F02C6/12
• CPC Class Codes: F16C 33/581 integral with other parts, e.g. with housings or machine elements such as shafts or gear wheels
• CPC Class Codes: F16C 33/768 between relatively stationary parts, i.e. static seals
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

A turbocharger is provided that includes a turbine, a compressor and a bearing housing disposed and connected between the turbine and the compressor. A shaft rotatably disposed within the bearing housing and extending into the turbine and the compressor. A bearing arrangement is disposed between the shaft and the bearing housing. The bearing arrangement including first and second bearings, each of the first and second bearings formed by a respective first and second plurality of roller elements engaged between a respective first and second inner race and a respective first and second outer race. The shaft is made of a steel alloy with a carbon content of less than 0.40% by weight.

Claims

1. A turbocharger, comprising:

a turbine that includes a turbine wheel;

a compressor that includes a compressor wheel;

a bearing housing disposed and connected between the turbine and the compressor, the bearing housing forming a bearing bore therethrough;

a shaft rotatahiy disposed within the bearing housing and extending into the turbine and the compressor, wherein the turbine wheel is connected to one end of the shaft and wherein the compressor wheel is connected to an opposite end of the shaft such that the turbine wheel is rotatably disposed in the turbine and the compressor wheel is rotatably disposed in the compressor;

a bearing arrangement disposed between the shaft and the bearing housing, the bearing arrangement including first and second bearings, each of the first and second bearings formed by a respective first and second plurality of roller elements engaged between a respective first and second inner race and a respective first and second outer race;

an outer bearing race element disposed within the bearing bore and forming the respective first and second outer races; and

an inner bearing race element disposed within the outer bearing race element and between the outer bearing race element and the shaft, the inner bearing race element forming the respective first and second inner races such that the respective first inner race is axially aligned with the respective first outer race, and the respective second inner race is axially aligned with the respective second outer race, the first inner being formed in a first end section of the inner bearing race element and the second inner race being formed in a second end section of the inner bearing race element and wherein the inner bearing race element includes a flared portion extending radially outwardly with respect to the respective first and second end sections of the inner bearing race element to provide torsional and bending rigidity to the shaft, the flared portion having a first inner diameter and the first and second end sections of the inner bearing race element each having a second inner diameter with the first inner diameter being greater than the second inner diameter;

wherein the shaft is made of a steel alloy with a carbon content of less than 0.40% by weight.

2. The turbocharger of claim 1, wherein the carbon content of the steel alloy of the is 0.30% by weight.

3. The turbocharger of claim 1, wherein the carbon content of the steel alloy of the shaft is between 0.28% to 0.33% by weight.

4. The turbocharger of claim 1, wherein the shaft is connected to the inner bearing race element at first and second end portions of the shaft, the first and second end portions of the shaft having a third diameter, the shaft further forming a slender portion between the first and second end portions, the slender portion having a fourth diameter that is less than the third diameter.

5. The turbocharger of claim 4, wherein the flared portion of the inner bearing race element overlaps in an axial direction with the slender portion of the shaft.

6. The turbocharger of claim 1, wherein the inner bearing race element is formed by two components, an outboard cup and an inboard cup.

7. The turbocharger of claim 6, wherein one of the inboard and outboard cups forms a ledge and a wall that accepts therein a free, annular face of the other cup.

8. The turbocharger of claim 1, wherein the flared portion of the inner bearing race element is flanked by two transition portions each of which connects the flared portion to a respective one of the first and second end sections of the inner bearing race element.

9. A turbocharger, comprising:

a turbine that includes a turbine wheel;

a compressor that includes a compressor wheel;

a bearing housing disposed and connected between the turbine and the compressor, the bearing housing forming a bearing bore therethrough;

a shaft rotatably disposed within the bearing housing and extending into the turbine and the compressor, wherein the turbine wheel is connected to one end of the shaft and wherein the compressor wheel is connected to an opposite end of the shaft such that the turbine wheel is rotatably disposed in the turbine and the compressor wheel is rotatably disposed in the compressor;

a bearing arrangement disposed between the shaft and the bearing housing, the bearing arrangement including first and second bearings, each of the first and second bearings formed by a respective first and second plurality of roller elements engaged between a respective first and second inner race and a respective first and second outer race;

an outer bearing race element disposed within the bearing bore and forming the respective first and second outer races; and

an inner bearing race element disposed within the outer bearing race element and between the outer bearing race element and the shaft, the inner bearing race element forming the respective first and second inner races such that the respective first inner race is axially aligned with the respective first outer race, and the respective second inner race is axially aligned with the respective second outer race, the first inner race being formed in a first end section of the inner bearing race element and the second inner race being formed in a second end section of the inner bearing element and wherein the inner bearing race element includes a flared portion extending radially outwardly with respect to the respective first and second end sections of the inner bearing race element to provide torsional and bending rigidity to the shaft, the flared portion having a first inner diameter and the first and second end sections of the inner bearing race element each having a second inner diameter with the first inner diameter being greater than the second inner diameter;

a nozzle ring disposed around the turbine wheel and including a plurality of vanes with flow channels being defined between the vanes that are in fluid communication a gas inlet passage and with the turbine wheel; and

a shroud arranged in surrounding relation to at least a portion of the turbine wheel;

wherein the flow channels defined by the vanes are configured to direct gas tangentially and radially inward toward an inner diameter of the turbine wheel and the shroud is configured to define a flow path in communication with the gas inlet passage and the flow channels, the flow path extending in a direction substantially parallel to a rotational axis of the turbine wheel;

wherein the shaft is made of a steel alloy with a carbon content of between 0.28% to 0.33% by weight.

10. The turbocharger of claim 9, wherein the carbon content of the steel alloy of the shaft is 0.30% by weight.

11. The turbocharger of claim 9, wherein the shaft is connected to the inner bearing race element at first and second end portions of the shaft, the first and second end portions of the shaft having a third diameter, the shaft further forming a slender portion between the first and second end portions, the slender portion having a fourth diameter that is less than the third diameter.

12. The turbocharger of claim 11, wherein the flared portion of the inner bearing race element overlaps in an axial direction with the slender portion of the shaft.

13. The turbocharger of claim 9, wherein the inner bearing race element is formed by two components, an outboard cup and an inboard cup.

14. The turbocharger of claim 13, wherein one of the inboard and outboard cups forms a ledge and a wall that accepts therein a free, annular face of the other cup.

15. The turbocharger of claim 9, wherein the flared portion of the inner bearing race element is flanked by two transition portions each of which connects the flared portion to a respective one of the first and second end sections of the inner bearing race element.

16. An internal combustion engine having a plurality of combustion chambers formed in a cylinder block, an intake manifold disposed to provide air or a mixture of air with exhaust gas to combustion chambers, and an exhaust manifold disposed to receive exhaust gas from the combustion chambers, the engine further comprising:

a turbine that includes a turbine housing surrounding a turbine wheel, the turbine housing being fluidly connected to the exhaust manifold and disposed to receive exhaust gas therefrom to drive the turbine wheel;

a compressor that includes a compressor housing that surrounds a compressor wheel, the compressor housing being fluidly connected to the intake manifold and disposed to provide air thereto;

a bearing housing disposed and connected between the turbine and the compressor, the bearing housing forming a bearing bore therethrough that accommodates a shaft interconnecting the turbine wheel and the compressor wheel to transfer power therebetween;

wherein the shaft is rotatably mounted within the bearing housing and extends into the turbine and the compressor such that the turbine wheel is connected to one end of the shaft and the compressor wheel is connected to an opposite end of the shaft;

a bearing arrangement disposed between the shaft and the bearing housing, the bearing arrangement including first and second bearings, each of the first and second bearings formed by a respective first and second plurality of roller elements engaged between a respective first and second inner race and a respective first and second outer race;

an outer bearing race element disposed within the bearing bore and forming the respective first and second outer races; and

an inner bearing race element disposed within the outer bearing race element and between the outer bearing race element and the shaft, the inner bearing race element forming the respective first and second inner races such that the respective first inner race is axially aligned with the respective first outer race, and the respective second inner race is axially aligned with the respective second outer race, the first inner race being formed in a first end section of the inner bearing race element and the second inner race being formed in a second end section of the inner bearing race element and wherein the inner bearing race element includes a flared portion extending radially outwardly with respect to the respective first and second end sections of the inner bearing race element to provide torsional and bending rigidity to the shaft, the flared portion having a first inner diameter and the first an second end sections of the inner bearing race element each having a second inner diameter with the first inner diameter being greater than the second inner diameter;

wherein the shaft is made of a steel alloy with a carbon content of between 0.28% to 0.30% by weight.

17. The engine of claim 16, wherein the carbon content of the steel alloy of the shaft is 0.30% by weight.