INSULATING SPACER FOR BALL BEARING CARTRIDGE

• US 20120023931A1
• Filed: 04/16/2010
• Published: 02/02/2012
• Est. Priority Date: 04/20/2009
• Status: Active Grant

• Current Assignee: BorgWarner Incorporated
• Original Assignee: BorgWarner Incorporated
• Inventors: House, Timothy, Diemer, Paul, Kelly, Allan, Cavagnaro, Augustine
• Granted Patent: US 8,814,538 B2
• Time in Patent Office: Days
• US Class Current: 60/598
• CPC Class Codes: F01D 25/16 Arrangement of bearings; Supporting or mounting bearings in casings bearings per se F16C
• 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: F02B 39/14 Lubrication of pumps; Safety measures therefor
• 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: F02C 7/06 Arrangements of bearings bearings F16C; Lubricating of turbo machines F01D25/18; of machines or engines in general F01M
• CPC Class Codes: F16C 19/184 in O-arrangement
• CPC Class Codes: F16C 19/525 related to temperature and heat, e.g. insulation
• CPC Class Codes: F16C 2360/24 Turbochargers in general F02C6/12

Abstract

A turbocharger using a high speed rolling element bearing system is improved in desired speed and life by providing an insulating spacer, with a thermal conductivity lower than that of the material in the inner race of the REB, between the turbine-end of the inner race of the bearing system and the compressor-end face of the piston ring boss to impede the flow of heat from the turbine wheel to the inner race of the rolling element bearing.

Claims

1. A turbocharger including

a rotating assembly comprising a shaft (50) and a turbine wheel (51) solidly affixed to one end of the shaft,

a bearing housing (3) supporting a rolling element bearing comprising an inner race (65) and an outer race (64) which are each provided with a raceway, and a series of rolling elements which are in contact with the raceways of each race,

wherein said shaft is supported for rotation by said rolling element bearing,

further comprising a thermal barrier element (90) carried on said shaft between said compressor wheel and said inner race.

2. The turbocharger as in claim 1, wherein said rotating assembly further comprises a piston ring boss (56) at the turbine end of the shaft, the piston ring boss (56) having a compressor-facing end (55), and wherein said thermal barrier element (90) is provided between said piston ring boss (56) compressor-facing end (55) and said inner race.

3. The turbocharger as in claim 1, wherein said thermal barrier element (90) is comprised of a material having a coefficient of thermal conductivity equal to or lower than that of either the bearing inner race or the bearing boss of the rotating assembly.

4. The turbocharger as in claim 1, wherein said thermal barrier element (90) is comprised of titanium, a titanium alloy, a superalloy, or a ceramic material.

5. The turbocharger as in claim 4, wherein said thermal barrier element (90) is comprised of a superalloy selected from the group consisting of Inconel, Incoloy, and Hastelloy.

6. The turbocharger as in claim 1, wherein said thermal barrier element (90) is comprised of a metal coated with a coating having a lower thermal conductivity than said metal.

7. The turbocharger as in claim 6, wherein said coating is a yttria-stabilized zirconia.

8. The turbocharger as in claim 1, wherein said inner race (65) is axially constrained by said thermal barrier element (90).

9. The turbocharger as in claim 1, wherein said thermal barrier element (90) includes a radial extension which serves as an oil flinger.

10. The turbocharger as in claim 1, wherein said thermal barrier element (90) has an inner race (65) contacting end face and said thermal barrier element (90) has an inner race (65) contacting end face, and wherein at least one of said end faces does not form a continuous ring with constant inner and outer diameter about it'"'"'s entire circumference.

11. The turbocharger as in claim 1, wherein said rolling element bearing is selected from the group consisting of ball bearings, roller bearings, needle bearings, tapered roller bearings, and spherical roller bearings.

12. A turbocharger including

a rotating assembly comprising a shaft (52) and a turbine wheel (51) solidly affixed to one end of the shaft, and a piston ring boss (56) at the turbine end of the shaft, the piston ring boss (56) having a compressor-facing end (55),

wherein at least one of said piston ring boss (56) compressor-facing end face (55) and said piston ring boss (56) facing inner race end face are coated with a low thermal conductance coating.