Turbocharger and Method

Patent metadata

Field	Value
Publication number	US-2016281644-A1
Application number	US-201514641660-A
Country	US
Kind code	A1
Filing date	Mar 9, 2015
Priority date	Mar 9, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

A turbocharger includes a turbine, a compressor, and a bearing housing forming a bearing bore. A bearing arrangement is disposed between a shaft interconnecting the turbine and compressor wheels, and the bearing housing. The bearing arrangement includes first and second bearings formed between an outer bearing race element disposed within the bearing bore 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 includes a flared portion extending radially outwardly to provide torsional and bending rigidity to the shaft.

First claim

We claim:

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 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; wherein the inner bearing race element includes a flared portion extending radially outwardly with respect to the respective first and second inner races to provide torsional and bending rigidity to the shaft.

2 . The turbocharger of claim 1 , wherein the flared portion forms an increased inner diameter of the inner bearing race element.

3 . The turbocharger of claim 2 , wherein the shaft is connected to the inner race at end portions, the end portions having a first diameter, the shaft further forming a slender portion between the end portions, the slender portion having a second diameter that is less than the first diameter.

4 . The turbocharger of claim 3 , wherein the increased inner diameter of the inner bearing race element overlaps in an axial direction with the slender portion of the shaft.

5 . The turbocharger of claim 1 , wherein the inner bearing race element is formed by two components, a compressor-side cup and a turbine-side cup.

6 . The turbocharger of claim 5 , wherein one of the turbine-side and compressor-side cups forms a ledge and a wall that accepts therein a free, annular face of the other cup.

7 . The turbocharger of claim 1 , wherein the flared portion is flanked by two transition portions that reduce an inner diameter of the flared portion to match an outer diameter of the shaft.

8 . The turbocharger of claim 7 , wherein each of the two transition portions has a smooth or chamfered profile.

9 . The turbocharger of claim 1 , wherein the inner bearing race element engages the shaft at two sides adjacent each respective first and second inner races such that a closed cavity is formed between an inner surface of the flared portion and an outer surface of the shaft, the closed cavity being generally disposed against ingress of lubricating oil therein.

10 . The turbocharger of claim 1 , wherein the inner bearing race element, the outer bearing race element, and the respective first and second pluralities of the roller elements are insertable together as an assembly into the bearing bore of the bearing housing around the shaft from one end, and are retained therein by a bearing retainer that is connected to the bearing housing.

11 . A method for rotatably supporting a shaft within a bearing housing of a turbocharger, comprising:
forming a first roller bearing by engaging a first plurality of rolling elements in a first inner race formed in an inner race element and in a first outer race formed in an outer race element; forming a second roller bearing by engaging a second plurality or rolling elements in a second inner race formed in the inner race element and in a second outer race formed in the outer race element; engaging the outer race element between a bearing bore formed in the bearing housing and the shaft extending through the bearing bore; wherein the inner bearing race element engages the shaft at two end portions and includes a flared portion between the two end portions such that the flared portion extends radially outwardly with respect to the end portions to provide torsional and bending rigidity to the shaft.

12 . The method of claim 11 , wherein the flared portion is hollow and forms an increased inner diameter of the inner bearing race element.

13 . The method of claim 12 , wherein engaging the shaft at the two end portions includes connecting the shaft to the inner race at the two end portions, each of the two end portions having a first diameter, wherein the shaft forms a slender portion between the two end portions, and wherein the slender portion has a second diameter that is less than the first diameter.

14 . The method of claim 13 , wherein the increased inner diameter of the inner bearing race element overlaps in an axial direction with the slender portion of the shaft.

15 . The method of claim 11 , further comprising assembling the inner bearing race element using a compressor-side cup and a turbine-side cup, wherein one of the turbine-side and compressor-side cups forms a ledge and a wall that accepts therein a free, annular face of the other cup.

16 . The method of claim 11 , wherein the flared portion is flanked by two transition portions that reduce an inner diameter of the flared portion to match an outer diameter of the shaft.

17 . The method of claim 16 , wherein each of the two transition portions has a smooth or chamfered profile.

18 . The method of claim 11 , further comprising forming a closed cavity between an inner surface of the flared portion and an outer surface of the shaft, the closed cavity being generally disposed against ingress of lubricating oil therein.

19 . The method of claim 11 , wherein the inner bearing race element, the outer bearing race element, and the respective first and second pluralities of the roller elements are insertable together as an assembly into the bearing bore of the bearing housing around the shaft from one end, and are retained therein by a bearing retainer that is connected to the bearing housing.

20 . 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 rotat

Assignees

• Caterpillar Inc

Inventors

• Annati Richard E
• Williams Thomas J

Classifications

• F01D25/162

  Bearing supports · CPC title

• F04D29/056

  Bearings · CPC title

• F02M25/0706 Primary

  Mechanical Engineering · mapped topic

• F16C2360/24

  Turbochargers · CPC title

• F16C2240/70

  Diameters; Radii · CPC title