(12) United States Patent (10) Patent No.: US 6,418,722 B1. Arnold (45) Date of Patent: Jul. 16, 2002

Transcription

1 USOO B1 (12) United State Patent (10) Patent o.: Arnold (45) Date of Patent: Jul. 16, 2002 (54) TURBOCHARGER BEARIG SYSTEM 4.322,949 A * 4/1982 Byrne et al /606 4,420,160 A 12/1983 Laham /40 (75) Inventor: Steven Don Arnold, Rancho Palo 4,664,605 A 5/1987 Aano et al /407 Verde, CA (US) 4,969,805. A 11/1990 Romeo /360 (73) Aignee: Honeywell International, Inc., * cited by examiner Morritown, J (US) * ) otice: Subject to any y diclaimer, the term of thi patent i extended or adjuted under 35 U.S.C. 4(b) by 0 day. Primary Examiner Hoang guyen (74) Attorney, Agent, or Firm-Ephram Starr; Felix Ficher (57) ABSTRACT (21) Appl. o.: 09/838,721 An enhanced bearing Sytem for turbocharger incorporate (22) Filed: Apr. 19, 2001 a thrut collar centrally mounted on the rotating haft (51) Int. Cl."... FO2B 33/44 interconnecting the turbine and compreor and a thrut (52)... 60/605.1; 417/407 bearing centrally located within the center houing to con (58) Field of Search train the thrut collar. Central placement of the thrut collar "60/ /407 allow journal bearing and journal Seal to be placed immediately adjacent the turbine and compreor wheel (56) Reference Cited attachment point O the haft enhancing the haft motion characteritic and Sealing capability. U.S. PATET DOCUMETS 4,7,834. A 6/1979 Burdette /13 4 Claim, 1 Drawing Sheet 24 Y / / / / Al 28 KT 18 2O 7 al S S. 3 O

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3 1 TURBOCHARGER BEARIG SYSTEM FIELD OF THE IVETIO Thi invention relate generally to the field of turbocharg ers and, more particularly, to a turbocharger bearing Sytem compriing a turbocharger haft thrut collar poitioned within a turbocharger center houing to provide a Smaller overall turbocharger package, and an overall better Stabi lized turbocharger haft operation. BACKGROUD OF THE IVETIO Turbocharger for gaoline and dieel internal combution engine are device known in the art that are ued for pressurizing or booting the intake air Stream, routed to a combution chamber of the engine, by uing the heat and Volumetric flow of exhaut ga exiting the engine. Specifically, the exhaut ga exiting the engine i routed into a turbine houing of a turbocharger in a manner that caue an exhaut ga-driven turbine to Spin within the houing. The exhaut ga-driven turbine i mounted onto one end of a haft that i common to a radial air compreor mounted onto an oppoite end of the haft. Thu, rotary action of the turbine alo caue the air compreor to Spin within a compreor houing of the turbocharger that i Separate from the exhaut houing. The Spinning action of the air com pressor caue intake air to enter the compreor houing and be preurized or booted a deired amount before it i mixed with fuel and combuted within the engine combu tion chamber. The common haft extending between the turbine and compreor i dipoed through a turbocharger center hou ing that include a bearing aembly for: (1) facilitating haft rotating action; (2) controlling axially directed haft thrut effect and radially directed haft vibration; (3) providing neceary lubrication to the rotating haft to minimize friction effect and related wear; and (4) providing a Seal between the lubricated aembly and the turbine and com pressor houing. The common haft a ued in turbocharger application i known to have haft-rotating Speed on the order of 120,000 to 0,000 rpm or higher. Under uch operating condition it i imperative that the bearing aem bly provide Shaft axial and radial Stabilization to maximize haft balance, thereby maximizing turbocharger houing ealability and compreor/turbine wheel tability. Variou prior art turbocharger houing bearing aemblie include a firt annular Seal at a houing turbine-side axial end, a Second journal bearing adjacent the firt annular Seal, a Secondjournal bearing, a generally dead Space between the firt and Second journal bearing, a thrut collar at a houing compreor-side axial end, and a Second annular Seal di poed adjacent the thrut collar. Configured in thi manner, a conventional turbocharger houing i axially lengthy, the journal bearing are Spaced relatively cloe together, and a relatively long moment arm or cantilever exit between the Second journal bearing and the compreor wheel. It i, therefore, deired that a turbocharger bearing Sytem be contructed that provide a more compact turbocharger package and better Shaft Stabilization and balance when compared to conventional bearing aemblie. It i further deired that the bearing Sytem be contructed to improve thee propertie without adverely impacting the lubricating and thrut load handling capabilitie of the bearing Sytem. SUMMARY OF THE IVETIO Turbocharger bearing Sytem, contructed according to principle of thi invention incorporate (1) a pair of journal 1O bearing dipoed adjacent repective compreor and tur bine end of the center houing; (2) a pair of journal Seal poitioned at adjacent repective compreor and turbine end of the center houing next to repective journal bear ing; and (3) a thrut collar dipoed within the center houing and interpoed between the journal bearing, wherein the thrut collar i poitioned at an approximate axial center of the houing and cooperate with a central houing flange to control axial haft movement. Configured in thi manner, bearing Sytem of thi invention improve haft Stability and balance, reduce turbocharger package ize, and improve center houing Sealability. BRIEF DESCRIPTIO OF THE DRAWIGS The invention will be better undertood with reference to the following drawing and detailed decription in which: FIG. 1 i an elevation Section view of a turbochager center houing and rotating aembly incorporating the preent invention. DETAILED DESCRIPTIO OF THE IVETIO A bearing ytem 10 of thi invention i illutrated FIG. 1. Generally, the bearing Sytem i dipoed within a turbo charger having an extended compreor houing backplate 12 and a center houing 13 having a central opening 14 extending axially therethrough from a turbine end 16 to a compreor end 18. The extended backplate attache to the center houing at an approximate midpoint of the turbo charger and the rotating group which include a turbine 20 i attached to one end of a haft 22 that project from end 16 of the houing. A compreor wheel 24 i attached to the oppoite end of the haft 22 that project from end 18 of the houing. Moving from left to right across the figure, the bearing Sytem of thi invention incorporate a firt annular Seal 26 that i dipoed within the houing opening 14 at end 18. The firt annular Seal ha a central Shaft opening 28 that i ized to accommodate placement of the Shaft 22 therein, and include a groove 30 dipoed circumferentially around an outide diameter Surface that i ized and haped to accom modate placement of a Seal ring 32 therein. The Seal ring 32 provide a leak-tight Seal between the firt annular Seal 26 and the central opening 14. The firt annular Seal extend axially a ditance within the houing and make abutting contact with a thrut collar 34. The thrut collar 34 comprie a central haft opening 36 to accommodate placement of the Shaft 22 therein, and include a firt diameter Section 38 that extend a ditance axially away from the firt annular Seal. AS better decribed below, the firt diameter ection 38 i ized having an outide diameter that fit within a firt journal bearing 40. The thrut collar 34 include firt and econd extended diameter Section 42 and 44 that are Spaced apart from one another, and that each extend radially outwardly a ditance away from the firt diameter ection 38. The extended diameter Section 42 and 44 are Separated by a reduced diameter Section 46 that, in a preferred embodiment, ha a diameter that i approximately that of the firt diameter Section 38. Each extended diameter ection include fron tide and backide axially-facing urface 48 and 50. The thrut collar 34 i retrained axially within the houing 12 by placement of the extended diameter Section 42 and 44 on either ide of a thrut bearing 52 that i Supported in the houing and extend radially inwardly toward the thrut collar. Specifically, the thrut bearing 52

4 3 i hore-shoe haped in the embodiment hown and ha an inide diameter 54 that i le than that of each extended diameter Section outide diameter, but that i lightly greater than that of the thrut collar reduced diameter ection 46 to trap the thrut collar axially within the houing. To provide fluid for the hydrodynamic bearing, the thrut bearing 52 can include an oil paage dipoed radially therethrough to facilitate lubricating the bearing and collar. In alternative embodiment, the thrut collar extended diameter Section and reduced diameter Section are divided into two or three eparate element to accommodate a 360 degree thrut bearing. A firt journal bearing 40 i dipoed axially within the houing central opening 14 between the firt annular Seal 26 and the thrut collar 34. The bearing 40 i annular, having an inide diameter 56 that i ized to accommodate placement of the thrut collar firt diameter ection 38 therein. The thrut collar firt diameter ection 56, thu extend axially completely through the firt journal bearing 40 Such that a thrut collar axial end 58 make abutting contact againt an adjacent firt annular eal axial urface 60. The firt journal bearing 40 include at leat one oil paage dipoed radially therethrough for facilitating oil paage to and from the journal bearing. Moving axially pat the thrut collar 34, the haft 22 include an enlarged diameter Section 63 that extend axially from the thrut collar extended diameter ection 44 backide axial Surface 50 to a econd annular eal 62. The enlarged diameter Section 63 make abutting contact againt the thrut collar and ha an outide diameter 64 that i ized to fit within a Second annular journal bearing 66 that i dipoed within the houing central opening 14. Specifically, the haft enlarged diameter Section i ized to fit within an inide diameter 68 of the econd annular journal bearing 66. The Second annular journal bearing 66 include one or more oil paage dipoed radially therethrough to facilitate the pa Sage of oil to and from the floating journal bearing. A Second annular journal Seal 62 i dipoed within the houing central opening 14, and comprie a groove 70 dipoed circumferentially there around, and a Seal ring 72 dipoed therein to provide a leak-tight Seal with the hou Ing. A key feature of turbocharger bearing Sytem of thi invention i the deign of the thrut collar that permit it placement within the middle of the turbocharger center houing, rather than at the houing compreor Side. Place ment of the thrut collar within the center of the houing i deirable becaue i reduce the overall axial length of the houing, when compared to a conventional houing built to accommodate a compreor-ide located thrut collar. Additionally, placement of the thrut collar in the center of the houing permit the journal bearing to be Spaced apart along the haft a greater ditance that wa previouly po Sible. The wider journal bearing Spacing within the houing i deired becaue it act to provide better Shaft Stabilization and balance, thereby improving journal bearing and journal Seal life. Further, relocating placement of the thrut collar from the houing compreor end, and the end of the bearing Sytem, reduce the amount of cantilever or overhang of the compreor wheel. Reducing thi overhang further improve haft balance, haft Sealing, and rotor Stability. The configu ration preerve the ability to aemble the turbocharger rotating group including the compreor wheel, Shaft, annu lar Seal, journal bearing, thrut collar and turbine wheel a a ingle unit with lockup provided through a threaded end nut 74 on the compreor wheel noe or a threaded hub on a compreor wheel without a through bore Having now decribed the invention in detail a required by the patent Statute, thoe killed in the art will recognize modification and Subtitution to the Specific embodiment dicloed herein. Such modification are within the Scope and intent of the preent invention a decribed in the following claim: What i claimed i: 1. A thrut collar for ue within a turbocharger having an elongated compreor backplate and a center houing com priing: an elongated firt diameter Section having a central tur bine Shaft opening dipoed axially therethrough from a firt axial end; a firt extended diameter Section extending radially out Wardly a ditance from the firt diameter Section, the firt extended diameter Section having axially-facing front and backide Surface, a Second extended diameter Section extending radially outwardly a ditance from the firt diameter Section and dipoed axially adjacent the firt extended diameter Section, the Second extended diameter Section having axially-facing front and backide Surface, the Second extended diameter Section backide Surface defining a bearing Second axial end; and a Second diameter Section interpoed between the firt and Second extended diameter Section, wherein, the firt diameter Section i received within a journal bearing and the firt and Second extended diameter Section engage a thrut bearing centrally mounted intermediate the elongated backplate and the center houing. 2. A turbocharger bearing Sytem dipoed within a tur bocharger having an elongated compreor backplate and a center houing compriing: firt and Second annular journal Seal dipoed within a turbocharger center houing central opening at oppoite houing axial end, firt and Second annular journal bearing dipoed within the houing axially inwardly of repective firt and Second annular journal Seal, a thrut collar dipoed near an axial center point of the houing and interpoed between the firt and Second annular journal bearing, the thrut collar including: a firt extended diameter Section that extend radially away from the firt diameter Section; a Second extended diameter Section dipoed axially adjacent the firt extended diameter Section, and that extend radially from the firt diameter Section; a Second diameter Section interpoed between the firt and Second extended diameter Section and that ha a diameter Similar to that of the firt diameter Sec tion; and a thrut bearing centrally mounted intermediate the elon gated backplate and the center houing and received between the firt and Second extended diameter Sec tion. 3. A turbocharger for an internal combution engine having a turbine houing, a compreor houing having an elongated compreor backplate attached thereto, a center houing interpoed between the turbine and compreor houing and an improved bearing compriing: a haft extending through the center houing and attached to a turbine wheel at one end extending into the turbine

5 S houing, and Said haft received into a compreor wheel bore at an oppoite Shaft end extending into the compreor houing; a bearing Sytem dipoed within the elongated backplate and center houing having firt and Second annular journal Seal dipoed within a central opening in the extended backplate and center houing at oppoite axial end of the haft; firt and Second annular journal bearing dipoed within the center houing axially inwardly of repective firt and Second annular journal Seal, a thrut collar dipoed near an axial center point of the houing and interpoed between the firt and Second annular journal bearing, the thrut collar including: a firt extended diameter Section that extend radially away from the firt diameter Section; a Second extended diameter Section dipoed axially adjacent the firt extended diameter Section, and that extend radially from the firt diameter Section; a Second diameter Section interpoed between the firt and Second extended diameter Section and that ha a diameter Similar to that of the firt diameter Sec tion; a thrut bearing centrally mounted intermediate the elon gated back plate and the center houing engaged inter mediate the thrut collar firt and Second extended diameter ection to axially fix the thrut collar within the houing, and mean for Securing the compreor wheel to the Shaft for lockup of the compreor wheel, firt and Second jour nal Seal, firt and Second journal bearing and thrut collar A turbocharger bearing Sytem dipoed within a tur bocharger having an elongated compreor backplate and a center houing compriing: firt and Second annular journal Seal dipoed within the turbocharger, wherein the firt annular journal Seal i dipoed within a central opening in the elongated compreor backplate adjacent a compreor wheel, and wherein the Second annular journal Seal i dipoed within a central opening in the center houing, firt and Second annular journal bearing dipoed within repective elongated compreor backplate and center houing central opening axially inwardly of repective firt and Second annular journal Seal, a thrut collar dipoed intermediate the elongated com pressor backplate and the center houing, and inter poed between the firt and Second annular journal bearing, the thrut collar including: a firt extended diameter Section that extend radially away from the firt diameter Section; a Second extended diameter Section dipoed axially adjacent the firt extended diameter Section, and that extend radially from the firt diameter Section; a Second diameter Section interpoed between the firt and Second extended diameter Section and that ha a diameter Similar to that of the firt diameter Sec tion; and a thrut bearing centrally mounted intermediate the elon gated compreor backplate and the center houing and received between the firt and Second extended diam eter Section.