Turbocharger and method of manufacturing floating bush

• US 9,726,189 B2
• Filed: 02/13/2012
• Issued: 08/08/2017
• Est. Priority Date: 03/29/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Ebisu, Motoki, Hayashi, Noriyuki, Shiraishi, Takashi, Nishida, Hideaki, Kamata, Keitaro, Ogita, Hiroshi, Tomita, Isao, Suzuki, Hiroshi
• Primary Examiner(s): Kim, Craig
• Assistant Examiner(s): Brockman, Eldon
• Application Number:
  US13/993,275
• Publication Number:
  US 20140010647A1
• Time in Patent Office: 2,003 Days
• CPC Class Codes: F01D 1/24 characterised by counter-rotating rotors subjected to same working fluid stream without intermediate stator blades or the like
• CPC Class Codes: F01D 25/16 Arrangement of bearings; Supporting or mounting bearings in casings bearings per se F16C
• CPC Class Codes: F01D 25/162 Bearing supports
• CPC Class Codes: F01D 25/166 Sliding contact bearing gas bearings F01D25/22
• CPC Class Codes: F01D 25/186 for sliding contact bearing
• CPC Class Codes: F04D 29/056 Bearings
• CPC Class Codes: F05D 2220/40 in turbochargers
• CPC Class Codes: F05D 2250/14 elliptical
• CPC Class Codes: F05D 2250/70 Shape
• CPC Class Codes: F05D 2260/96 Preventing, counteracting or reducing vibration or noise
• CPC Class Codes: F16C 17/028 with fixed wedges to generate hydrodynamic pressure, e.g. multi-lobe bearings
• CPC Class Codes: F16C 17/18 with floating brasses or brushing, rotatable at a reduced speed F16C17/03, F16C17/06 take precedence
• CPC Class Codes: F16C 17/26 Systems consisting of a plurality of sliding-contact bearings
• CPC Class Codes: F16C 2220/40 by deformation without removing material
• CPC Class Codes: F16C 2220/60 by removing material, e.g. machining
• CPC Class Codes: F16C 2220/70 by grinding
• CPC Class Codes: F16C 2360/24 Turbochargers
• CPC Class Codes: F16C 33/1075 Wedges, e.g. ramps or lobes, for generating pressure
• CPC Class Codes: F16C 33/14 Special methods of manufacture; Running-in
• CPC Class Codes: F16C 43/02 Assembling sliding-contact bearings
• CPC Class Codes: Y10T 29/49668 : Sleeve or bushing making

Abstract

A turbocharger and a method of manufacturing a floating bush with which noise can be reduced, and the rotation speed can be increased. In a turbocharger in which a rotating shaft having a circular cross-section and connecting a turbine rotor and a compressor rotor is supported in a freely rotatable manner, at two axially separated positions via floating bushes, by an inner circumferential surface disposed so as to surround the rotating shaft in a bearing housing, an inner circumferential surface of each of the floating bushes has a non-circular shape in which the curvature of the cross-sectional shape varies in the circumferential direction.

Claims

1. A turbocharger in which a rotating shaft having a circular cross-section and connecting a turbine rotor and a compressor rotor is supported in a freely rotatable manner, at two axially separated positions via floating bushes, by a support portion disposed so as to surround the rotating shaft in a housing,

wherein an inner circumferential surface of each of the floating bushes has an elliptical shape in which a curvature of a cross-section varies in a circumferential direction, and

a pair of the floating bushes are connected together, and phases of the ellipses formed on the inner circumferential surfaces of the floating bushes are shifted from each other.

2. The turbocharger according to claim 1, wherein an inner circumferential surface of the support portion has a non-circular shape in which a curvature of a cross-section varies in a circumferential direction.

3. The turbocharger according to claim 1 wherein the phases of the ellipses formed on the inner circumferential surfaces of the floating bushes are shifted from each other by 90°

.

4. A method of manufacturing a floating bush that supports a rotating shaft having a circular cross-section and connecting a turbine rotor and a compressor rotor, the floating bush having an inner circumferential surface that has a non-circular cross-section, the method comprising:

deforming a cylindrical member into a flattened shape by applying pressing forces to a side surface thereof from two opposing directions with respect to an axis;

forming a hole having a circular shape centered on the axis so as to penetrate the deformed cylindrical member; and

removing the pressing forces.