US20150044047A1 - Turbocharger having a connector for connecting an impeller to a shaft - Google Patents
Turbocharger having a connector for connecting an impeller to a shaft Download PDFInfo
- Publication number
- US20150044047A1 US20150044047A1 US14/370,894 US201214370894A US2015044047A1 US 20150044047 A1 US20150044047 A1 US 20150044047A1 US 201214370894 A US201214370894 A US 201214370894A US 2015044047 A1 US2015044047 A1 US 2015044047A1
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- United States
- Prior art keywords
- impeller
- connector
- shaft
- coefficient
- thermal expansion
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- Abandoned
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Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/02—Blade-carrying members, e.g. rotors
- F01D5/025—Fixing blade carrying members on shafts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/58—Cooling; Heating; Diminishing heat transfer
- F04D29/582—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps
- F04D29/5853—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps heat insulation or conduction
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D25/00—Pumping installations or systems
- F04D25/02—Units comprising pumps and their driving means
- F04D25/024—Units comprising pumps and their driving means the driving means being assisted by a power recovery turbine
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/02—Selection of particular materials
- F04D29/023—Selection of particular materials especially adapted for elastic fluid pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/26—Rotors specially for elastic fluids
- F04D29/266—Rotors specially for elastic fluids mounting compressor rotors on shafts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/26—Rotors specially for elastic fluids
- F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
- F04D29/284—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps for compressors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/60—Mounting; Assembling; Disassembling
- F04D29/601—Mounting; Assembling; Disassembling specially adapted for elastic fluid pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D1/00—Couplings for rigidly connecting two coaxial shafts or other movable machine elements
- F16D1/06—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end
- F16D1/08—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key
- F16D1/0829—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key with radial loading of both hub and shaft by an intermediate ring or sleeve
- F16D1/0835—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key with radial loading of both hub and shaft by an intermediate ring or sleeve due to the elasticity of the ring or sleeve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2220/00—Application
- F05D2220/40—Application in turbochargers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/10—Metals, alloys or intermetallic compounds
- F05D2300/17—Alloys
- F05D2300/171—Steel alloys
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/10—Metals, alloys or intermetallic compounds
- F05D2300/17—Alloys
- F05D2300/173—Aluminium alloys, e.g. AlCuMgPb
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/50—Intrinsic material properties or characteristics
- F05D2300/502—Thermal properties
- F05D2300/5021—Expansivity
- F05D2300/50212—Expansivity dissimilar
Definitions
- the present invention relates to a connector for connecting an impeller to a shaft, and in particular, but not exclusively, for connecting an impeller of a turbocharger to a turbocharger shaft.
- Turbocharger impellers are typically made of aluminium alloys to provide low rotational inertia with reasonable strength at a commercially-acceptable cost. Attachment of the impeller to the steel turbocharger shaft is achieved in various ways. For example, because of the relative weakness of aluminium and the small diameter of the shaft, one option is to provide the impeller with a steel insert containing a screw-threaded socket which can be threaded on to the shaft. This arrangement can take a higher torque than a connection in which the shaft is directly threaded into the aluminium body (the torque is proportional to the power transmitted across the joint, and so the impeller can be used at a higher pressure ratio than one in which there is a direct threaded connection).
- such an insert is fitted into the impeller by shrink fitting; the aluminium body of the impeller is heated to expand the bore which is to receive the steel insert, while the insert is cooled, for example using liquid nitrogen, before being inserted into the bore.
- the resultant interference connection is restricted by the temperature to which the aluminium can be heated before its material properties are affected, and by the temperature to which the steel can be cooled.
- the turbocharger then starts to heat up, and because of the different thermal coefficients of expansion of the aluminium alloy and the steel, the aluminium grows axially more than the steel, causing the two metals to slide over each other, except at the location where the impeller still grips the insert firmly.
- the centrifugal stresses are removed, but the thermal stresses remain for some minutes as the turbocharger cools. In this process, the point of grip of the impeller on the insert changes from one end to the other, and as the turbocharger cools, the insert “walks” along the impeller.
- EP1394387 proposes an outer steel constraining ring which reinforces the frictional contact between aluminium impeller and the insert. Since the ring does not expand as much as the impeller body as the turbocharger heats up, the point of grip between the impeller and the insert remains within the axial extent of the ring during the whole operating cycle of the turbocharger, thereby preventing the tendency of the impeller to “walk” along the insert. As a consequence, the operating life of the turbocharger can be considerably extended in comparison with the conventional turbocharger without the constraining ring.
- the assembly of such a joint is relatively complex. First the insert and impeller bore are manufactured to tight tolerances. Then typically the insert is cooled and the impeller heated, and the insert is placed within the impeller bore at a hub extension of the impeller. As the insert warms up and the impeller cools, a shrink fit joint is formed, but because of the non-axisymmetrical shape of the impeller, some distortion occurs within the impeller. Generally, the outer surface of the impeller hub extension must therefore be reground to be axisymmetric so that it will be suitable for the outer joint with the constraining ring. A further ring may then be shrunk onto a flange portion of the insert to prevent the constraining ring from coming off the impeller.
- the present invention provides a connector for connecting an impeller to a shaft, in particular for connecting an impeller of a turbocharger to a turbocharger shaft, the impeller having a shaft-side hub extension with a central recess, and the impeller being formed of a respective material having a greater coefficient of thermal expansion than the material of the shaft, wherein:
- the connector By forming the connector from a material having such a coefficient of thermal expansion, the differential thermal forces which encourage the impeller to “walk” can be reduced, thereby reducing any tendency of the impeller to “walk” while maintaining the torque capacity of the joint.
- regrinding of the hub extension can also be avoided after fitting of the connector, as it is usually unnecessary to fit a constraining ring of the type described in EP1394387 to the hub extension.
- a second aspect of the invention provides an impeller having a shaft-side hub extension with a central recess and fitted with a connector according to the first aspect, the connector being frictionally connected at an outwardly facing surface with a radially inner surface of the hub extension.
- a third aspect of the invention provides the impeller fitted with a connector of the second aspect, which impeller is connected to a shaft having a corresponding threaded section, the thread of the threaded portion of the connector screwing onto the corresponding threaded portion of the shaft.
- a fourth aspect of the invention provides a turbocharger having the connected impeller and shaft of the third aspect.
- the central recess may be a blind hole (i.e. with an end surface).
- the impeller may not have a through-hole extending from one side to another of the impeller.
- the outwardly facing surface of the connector may be approximately cylindrically shaped.
- the radially inner surface of the shaft-side hub extension of the impeller which frictionally connects with the outwardly facing surface may be correspondingly approximately cylindrical.
- the frictional connection between the connector and the hub extension can be achieved by e.g. press fitting or shrink fitting.
- shrink fitting can be used to produce a tighter interference with the impeller, while maintaining the temperatures to which the connector is cooled and the impeller is heated during fitting.
- the connector (which provides the outwardly facing surface and the threaded portion) can be formed as a unitary body.
- the threads can be positive-locking, e.g. tapered.
- the connector can have an abutment surface (e.g. provided by a flange portion) which engages a corresponding abutment surface (e.g. provided by a shoulder) of the shaft when the thread portions are screwed together, thereby tightening the threads to provide the rotationally fixed connection.
- the threads carried by the threaded portion of the connector may be protected by a helicoil formation fitted to the connector.
- the helicoil formation can thereby prevent damage to the threads of the connector.
- the threaded portion of the connector can be within the central recess. In this way, an axially compact arrangement can be achieved.
- the frictional connection between the outwardly facing surface of the connector and the radially inner surface of the hub extension transmits, in use, substantially all of the torque between the shaft and the impeller.
- the connector may be formed of a material having a greater strength than the material of the impeller.
- the connector may be formed of a material having a lower coefficient of thermal expansion than the material of the impeller.
- the shaft can be formed of steel (e.g. a high strength steel), which typically has a coefficient of thermal expansion of about 11 ⁇ 10 ⁇ 6 /K
- the impeller can be formed of aluminium alloy, which typically has a coefficient of thermal expansion of about 22.7 ⁇ 10 ⁇ 6 /K.
- the connector is formed of a material that is resistant to galling with the shaft.
- the connector can be formed, for example, of magnesium alloy, bronze, brass or stainless steel.
- a value for the coefficient of thermal expansion of the connector that is equal to or close to that of the impeller is preferred for reducing the differential thermal forces which encourage the impeller to “walk”. Therefore, preferably the value of ( ⁇ c ⁇ s )/( ⁇ i ⁇ s ) is greater than 0.2, and more preferably greater than 0.3 or 0.4, where, ⁇ c is the coefficient of thermal expansion of the connector, ⁇ i is the coefficient of thermal expansion of the impeller, and ⁇ s is the coefficient of thermal expansion of the shaft.
- ⁇ c is the coefficient of thermal expansion of the connector
- ⁇ i is the coefficient of thermal expansion of the impeller
- ⁇ s is the coefficient of thermal expansion of the shaft.
- the value of ( ⁇ c ⁇ s )/( ⁇ i ⁇ s ) is less than 0.9, and more preferably less than 0.8 or 0.7.
- this does not exclude that the value of ( ⁇ c ⁇ s )/( ⁇ i ⁇ s ) can be equal to or greater than 1.
- higher values of ( ⁇ c ⁇ s )/( ⁇ i ⁇ s ) can be adopted without risk of shaft breakage.
- one option is to form the impeller of a material having a relatively low coefficient of thermal expansion, such as silicon carbide reinforced aluminium alloy which, depending on the volume of silicon carbide, typically has a coefficient of thermal expansion in the range of from 14 to 17 ⁇ 10 ⁇ 6 /K.
- a relatively high coefficient of thermal expansion for the connector not only can reduce any tendency of the impeller to “walk”, but also can assist with the production of a shrink fitted frictional connection between the connector and the hub extension.
- the connector and/or the impeller may have one or more centring portions having respective engagement surfaces which engage with one or more corresponding centring portions of the shaft, the threaded portion of the connector and the centring portions of the connector and/or the impeller being distributed along the impeller axis.
- the thread surface of the connector and the engagement surfaces of the connector and/or the impeller can face radially inwardly, and the respective diameters on the shaft of the thread and the engagement surfaces can then decrease towards the impeller.
- the impeller has a casing, and the connector and/or the hub extension can then form a seal with a section of the casing.
- the seal can include a sealing ring, which may be carried by the casing section and which may be received by a corresponding circumferential recess formed on an outer surface of the connector and/or the hub extension.
- the sealing ring may have one or more annular grooves on its radially inner face, and the recess may have corresponding circumferential ribs which are received in the grooves.
- the seal may include a labyrinth seal, with formations on facing surfaces of the casing section and the connector and/or the hub extension forming the labyrinth.
- the connector may be formed with or may carry a circumferential oil thrower formation at its radially outer surface.
- FIG. 1 is a sectional elevation through a turbocharger impeller joined to a shaft by a connector in accordance with an embodiment of the invention
- FIG. 2 is a close-up schematic view of a seal between a section of a casing of the impeller of FIG. 1 and a hub extension of the impeller;
- FIG. 3 is a close-up schematic view of a seal between a section of a casing of an impeller and a sleeve portion of a further embodiment of the connector;
- FIG. 4 shows schematically a sectional elevation of a further embodiment of the connector.
- an aluminium alloy impeller 1 is fitted on to a steel turbocharger shaft 2 by means of a connector 3 .
- the alloy of which the impeller is made (known in the U.S.A. by the designation “2618A”) has a relatively high strength for use up to a temperature of about 200° C., having a composition of aluminium with about 2.5 wt. % copper and smaller amounts of magnesium, iron and nickel.
- the alloy of the impeller 1 has a coefficient of thermal expansion of about 22.7 ⁇ 10 ⁇ 6 /K, and the steel of the shaft 2 has a coefficient of thermal expansion of about 11 ⁇ 10 ⁇ 6 /K.
- the material of the connector 3 preferably has a coefficient of thermal expansion such that the value of ( ⁇ c ⁇ s )/( ⁇ i ⁇ s ) is greater than 0.2, and more preferably greater than 0.3 or 0.4.
- the connector 3 may be made of magnesium alloy (coefficient of thermal expansion of about 26 ⁇ 10 ⁇ 6 /K), bronze (coefficient of thermal expansion typically of about 18 ⁇ 10 ⁇ 6 /K, although as high as 20-21 ⁇ 10 ⁇ 6 /K for manganese-bronze), brass (coefficient of thermal expansion of about 18.7 ⁇ 10 ⁇ 6 /K) or stainless steel (coefficient of thermal expansion of in the range of 16-17.3 ⁇ 10 ⁇ 6 /K).
- magnesium alloy coefficient of thermal expansion of about 26 ⁇ 10 ⁇ 6 /K
- bronze coefficient of thermal expansion typically of about 18 ⁇ 10 ⁇ 6 /K, although as high as 20-21 ⁇ 10 ⁇ 6 /K for manganese-bronze
- brass coefficient of thermal expansion of about 18.7 ⁇ 10 ⁇ 6 /K
- stainless steel coefficient of thermal expansion of in the range of 16-17.3 ⁇ 10 ⁇ 6 /K.
- Such alloys can also be resistant to galling with the steel of the shaft 2 .
- the connector 3 is of cup-like shape and has an outer surface 14 for connecting to the impeller 1 , a threaded portion 12 with a threaded bore 11 forming the base of the cup, and a flange portion 8 around the mouth of the cup.
- the shaft 2 is formed at its end with a first shoulder 4 surrounding a cylindrical centring portion 5 , and a screw-threaded portion 7 of further reduced diameter extending from the end of the centring portion.
- the connector 3 is inserted into a blind central recess formed in the hub extension H, with the outer surface 14 of the connector 3 frictionally connected to the radially inner surface of the hub extension H.
- the flange portion 8 of the connector 3 engages against a shaft-side end face 9 of the hub extension H to determine the relative axial positions of the connector 3 and the hub extension H.
- the flange portion 8 is engaged on its other side by the shoulder 4 on the shaft 2 .
- the centring portion 5 of the shaft is received in a corresponding centring portion 10 of the connector in a close, but not tight, fit.
- the threaded bore 11 engages on the screw-threaded portion 7 of the shaft.
- the threaded portion 12 has a small clearance from the end of the recess.
- the connector 3 is fitted on to the hub extension H by cooling the connector 3 to cause it to shrink and by heating the impeller to cause the hub extension H to expand, and then inserting the connector 3 into the central recess of the hub extension H until the flange portion 8 contacts the end face 9 of the hub extension H.
- the connector 3 and hub extension H frictionally grip across the outer surface 14 of the connector 3 and the radially inner surface of the hub extension H.
- the outer surface 14 extends over and thereby frictionally contacts most of the axial length of the hub extension H.
- the outer diameter of the flange portion 8 is provided with an oil capture/thrower ring R, which in this embodiment of the invention is machined into the flange portion 8 .
- a section 15 of the impeller casing and the outer surface of the hub extension H are in close proximity to help provide a rotating oil and pressure seal between the impeller 1 and the casing.
- the hub extension H has a recess 13 on its outer surface which is bounded at one end by the flange portion 8 of the first component of the connector and which receives a sealing ring 16 carried by the casing section 15 .
- the casing section 15 has a small abutment surface 20 on the shaft side (right hand in FIG. 1 ) of the seal ring 16 and against which the sealing ring 16 rests.
- the sealing ring 16 has annular grooves 18 on its radially inner face, and the recess has corresponding circumferential ribs 17 which are received in the grooves, as described in EP A 1130220.
- the sealing ring can be a plain ring (i.e. without grooves) received in a plain recess (i.e. without ribs).
- the sealing ring 16 co-operates with the casing section 15 and serves to retain lubricating oil to the shaft side of the assembly and compressed air to the impeller side of the assembly (left hand in FIG. 1 ).
- the compressed air is contained between the body of the impeller 1 , the hub extension H with its sealing ring 16 , and the impeller casing, within which the impeller assembly is mounted for rotation on overhung bearings (not shown).
- the screw-threaded portion 7 of the shaft 2 is screwed onto the threaded portion 12 of the connector 3 , the respective centring portions 5 , 10 ensuring the shaft aligns with the axis of the impeller.
- the threads are screwed until opposing surfaces of the flange portion 8 and shoulder 4 come into abutment, which causes the threads to tighten and provides a rotationally fixed connection between the impeller 1 and the shaft 2 .
- the connector 3 by forming the connector 3 from a material having an intermediate coefficient of thermal expansion, the differential thermal forces acting across the frictional connection between the connector 3 and the impeller 1 can be reduced relative to a connector formed from the a material having the same coefficient of thermal expansion as that of the shaft. In this way, the tendency for the impeller to “walk” can also be reduced, which allows the impeller to be driven by a higher torque and therefore increases the maximum pressure ratio of the impeller.
- an axially compact arrangement is achieved.
- the frictional connection between the connector 3 and the impeller transmits, in use, substantially all of the torque between the shaft 2 and the impeller 1 . Further, as there is no need to fit a constraining ring of the type described in EP1394387 to the hub extension H, regrinding operations can be avoided during fitting of the connector 3 .
- the impeller 1 If there is any tendency for the impeller 1 to “walk”, advantageously this can be monitored by measuring the size of the gap that would open up between the flange portion 8 and the end face 9 . For this reason, it is preferred that the flange portion 8 and the end face 9 determine the relative axial positions of the connector 3 and the hub extension H.
- Alternative pairs of facing features that could be configured to abut each and thereby determine the relative axial positions (such as the threaded portion 12 and the end of the recess) are less amenable to inspection.
- FIG. 3 is a close-up schematic view of a seal between a section of a casing of an impeller and the flange portion 8 of a further embodiment of the connector 3 .
- the hub extension H and flange portion 8 on one side and the casing section 15 on the other side have engaging surfaces 19 carrying respective sets of machined grooves which interlock to form a labyrinth seal.
- FIG. 4 shows schematically a sectional elevation of a further embodiment of the connector.
- This embodiment is similar to the embodiment of FIG. 1 except that the shaft 2 has two centring portions 5 a, 5 b, and the connector has two corresponding centring portions 10 a, 10 b.
- the threaded portions 7 , 12 of the shaft 2 and the connector are located axially between the engaging pairs of centring portions such that, on each of the shaft and the connector, the respective diameters of the threaded portions and the centring portions decrease towards the impeller.
- the threads are tapered, so that merely screwing the threaded portions 7 , 12 together results in a rotationally fixed connection between the impeller 1 and the shaft 2 .
- the impeller may have a centring portion at the base of the recess that engages with the centring portion 5 b of the shaft.
- the threads carried by the threaded portion 12 of the connector 3 may be protected by a helicoil formation to prevent damage to the threads of the connector 3 from the stronger material of the shaft 1 .
Abstract
A connector for connecting an impeller to a shaft is provided. The impeller has a shaft-side hub extension with a central recess. The impeller is formed of a material having a greater coefficient of thermal expansion than the material of the shaft. The connector is inserted into the recess to frictionally connect an outwardly facing surface of the connector with a radially inner surface of the hub extension. The connector has a threaded portion carrying a thread which screws onto a corresponding threaded portion of the shaft, such that the connector provides a rotationally fixed connection between the impeller and the shaft. The connector is formed of a material having a coefficient of thermal expansion which is greater than the coefficient of thermal expansion of the material of the shaft.
Description
- Not applicable.
- Not applicable.
- Not applicable.
- 1. Field of the Invention
- The present invention relates to a connector for connecting an impeller to a shaft, and in particular, but not exclusively, for connecting an impeller of a turbocharger to a turbocharger shaft.
- 2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
- Turbocharger impellers are typically made of aluminium alloys to provide low rotational inertia with reasonable strength at a commercially-acceptable cost. Attachment of the impeller to the steel turbocharger shaft is achieved in various ways. For example, because of the relative weakness of aluminium and the small diameter of the shaft, one option is to provide the impeller with a steel insert containing a screw-threaded socket which can be threaded on to the shaft. This arrangement can take a higher torque than a connection in which the shaft is directly threaded into the aluminium body (the torque is proportional to the power transmitted across the joint, and so the impeller can be used at a higher pressure ratio than one in which there is a direct threaded connection).
- Typically, such an insert is fitted into the impeller by shrink fitting; the aluminium body of the impeller is heated to expand the bore which is to receive the steel insert, while the insert is cooled, for example using liquid nitrogen, before being inserted into the bore. The resultant interference connection is restricted by the temperature to which the aluminium can be heated before its material properties are affected, and by the temperature to which the steel can be cooled.
- While the arrangement described can perform satisfactorily, a problem can arise during cycling of the turbocharger from rest to full load. As the turbocharger starts to spin, the joint is affected by centrifugal forces, whereby the aluminium grows outwards away from the steel insert. This reduces the interference force between the insert and the impeller, and due to design constraints it has been found that this reduction tends to be greater at one end of the insert than at the other. Consequently, the insert is gripped more firmly at one of its ends than at the other. The turbocharger then starts to heat up, and because of the different thermal coefficients of expansion of the aluminium alloy and the steel, the aluminium grows axially more than the steel, causing the two metals to slide over each other, except at the location where the impeller still grips the insert firmly. On shutdown, the centrifugal stresses are removed, but the thermal stresses remain for some minutes as the turbocharger cools. In this process, the point of grip of the impeller on the insert changes from one end to the other, and as the turbocharger cools, the insert “walks” along the impeller.
- In certain very cyclic conditions (for example fast ferry applications in high ambient temperatures), it has been observed that the insert can move so far along the impeller that turbocharger failure can occur. Although the effect can be mitigated to some degree by increasing the original interference between the components, for the reasons mentioned above this solution is limited, and it is therefore desirable to achieve a design which ensures that the point of grip remains at the same location during the operating cycles, rather than shifting from one end of the insert to the other.
- Accordingly, EP1394387 proposes an outer steel constraining ring which reinforces the frictional contact between aluminium impeller and the insert. Since the ring does not expand as much as the impeller body as the turbocharger heats up, the point of grip between the impeller and the insert remains within the axial extent of the ring during the whole operating cycle of the turbocharger, thereby preventing the tendency of the impeller to “walk” along the insert. As a consequence, the operating life of the turbocharger can be considerably extended in comparison with the conventional turbocharger without the constraining ring.
- However, the assembly of such a joint is relatively complex. First the insert and impeller bore are manufactured to tight tolerances. Then typically the insert is cooled and the impeller heated, and the insert is placed within the impeller bore at a hub extension of the impeller. As the insert warms up and the impeller cools, a shrink fit joint is formed, but because of the non-axisymmetrical shape of the impeller, some distortion occurs within the impeller. Generally, the outer surface of the impeller hub extension must therefore be reground to be axisymmetric so that it will be suitable for the outer joint with the constraining ring. A further ring may then be shrunk onto a flange portion of the insert to prevent the constraining ring from coming off the impeller.
- It would be desirable to provide a connection between an impeller and a shaft which is simpler to install, but one that can transmit high torques and can prevent or reduce any tendency of the impeller to “walk”.
- Accordingly, in a first aspect the present invention provides a connector for connecting an impeller to a shaft, in particular for connecting an impeller of a turbocharger to a turbocharger shaft, the impeller having a shaft-side hub extension with a central recess, and the impeller being formed of a respective material having a greater coefficient of thermal expansion than the material of the shaft, wherein:
-
- the connector is inserted into the recess to frictionally connect an outwardly facing surface of the connector with a radially inner surface of the hub extension;
- the connector has a threaded portion carrying a thread which screws onto a corresponding threaded portion of the shaft, such that the connector provides a rotationally fixed connection between the impeller and the shaft; and
- the connector is formed of a material having a coefficient of thermal expansion which is greater than the coefficient of thermal expansion of the material of the shaft.
- By forming the connector from a material having such a coefficient of thermal expansion, the differential thermal forces which encourage the impeller to “walk” can be reduced, thereby reducing any tendency of the impeller to “walk” while maintaining the torque capacity of the joint. In addition, regrinding of the hub extension can also be avoided after fitting of the connector, as it is usually unnecessary to fit a constraining ring of the type described in EP1394387 to the hub extension.
- A second aspect of the invention provides an impeller having a shaft-side hub extension with a central recess and fitted with a connector according to the first aspect, the connector being frictionally connected at an outwardly facing surface with a radially inner surface of the hub extension.
- A third aspect of the invention provides the impeller fitted with a connector of the second aspect, which impeller is connected to a shaft having a corresponding threaded section, the thread of the threaded portion of the connector screwing onto the corresponding threaded portion of the shaft.
- A fourth aspect of the invention provides a turbocharger having the connected impeller and shaft of the third aspect.
- Optional features of the invention will now be set out. These are applicable singly or in any combination with any aspect of the invention.
- The central recess may be a blind hole (i.e. with an end surface). Thus, the impeller may not have a through-hole extending from one side to another of the impeller.
- The outwardly facing surface of the connector may be approximately cylindrically shaped. The radially inner surface of the shaft-side hub extension of the impeller which frictionally connects with the outwardly facing surface may be correspondingly approximately cylindrical.
- The frictional connection between the connector and the hub extension can be achieved by e.g. press fitting or shrink fitting. In particular, as the connector material has a higher coefficient of thermal expansion than that of a conventional connector, shrink fitting can be used to produce a tighter interference with the impeller, while maintaining the temperatures to which the connector is cooled and the impeller is heated during fitting.
- The connector (which provides the outwardly facing surface and the threaded portion) can be formed as a unitary body.
- To provide the rotationally fixed connection, the threads can be positive-locking, e.g. tapered. However, another option is for the connector to have an abutment surface (e.g. provided by a flange portion) which engages a corresponding abutment surface (e.g. provided by a shoulder) of the shaft when the thread portions are screwed together, thereby tightening the threads to provide the rotationally fixed connection.
- The threads carried by the threaded portion of the connector may be protected by a helicoil formation fitted to the connector. As the material of the connector may be less strong than the material of the shaft, the helicoil formation can thereby prevent damage to the threads of the connector.
- The threaded portion of the connector can be within the central recess. In this way, an axially compact arrangement can be achieved.
- Preferably, the frictional connection between the outwardly facing surface of the connector and the radially inner surface of the hub extension transmits, in use, substantially all of the torque between the shaft and the impeller.
- The connector may be formed of a material having a greater strength than the material of the impeller. The connector may be formed of a material having a lower coefficient of thermal expansion than the material of the impeller. For example, the shaft can be formed of steel (e.g. a high strength steel), which typically has a coefficient of thermal expansion of about 11×10−6/K , and the impeller can be formed of aluminium alloy, which typically has a coefficient of thermal expansion of about 22.7×10−6/K. Preferably the connector is formed of a material that is resistant to galling with the shaft. The connector can be formed, for example, of magnesium alloy, bronze, brass or stainless steel. Generally, a value for the coefficient of thermal expansion of the connector that is equal to or close to that of the impeller is preferred for reducing the differential thermal forces which encourage the impeller to “walk”. Therefore, preferably the value of (αc−αs)/(αi−αs) is greater than 0.2, and more preferably greater than 0.3 or 0.4, where, αc is the coefficient of thermal expansion of the connector, αi is the coefficient of thermal expansion of the impeller, and αs is the coefficient of thermal expansion of the shaft. However, a risk of a coefficient of thermal expansion of the connector which is much greater than that of the shaft is that the resultant stretching of the shaft at high temperatures could lead to shaft breakage. Therefore, at least for typical materials for the impeller and shaft (such as respectively aluminium alloy and steel), preferably the value of (αc−αs)/(αi−αs) is less than 0.9, and more preferably less than 0.8 or 0.7. However, this does not exclude that the value of (αc−αs)/(αi−αs) can be equal to or greater than 1. In particular, if the value of (αi−αs) is reduced, then higher values of (αc−αs)/(αi−αs) can be adopted without risk of shaft breakage. Thus one option is to form the impeller of a material having a relatively low coefficient of thermal expansion, such as silicon carbide reinforced aluminium alloy which, depending on the volume of silicon carbide, typically has a coefficient of thermal expansion in the range of from 14 to 17×10−6/K. In such cases, a relatively high coefficient of thermal expansion for the connector not only can reduce any tendency of the impeller to “walk”, but also can assist with the production of a shrink fitted frictional connection between the connector and the hub extension.
- The connector and/or the impeller may have one or more centring portions having respective engagement surfaces which engage with one or more corresponding centring portions of the shaft, the threaded portion of the connector and the centring portions of the connector and/or the impeller being distributed along the impeller axis. The thread surface of the connector and the engagement surfaces of the connector and/or the impeller can face radially inwardly, and the respective diameters on the shaft of the thread and the engagement surfaces can then decrease towards the impeller.
- Generally the impeller has a casing, and the connector and/or the hub extension can then form a seal with a section of the casing. For example, the seal can include a sealing ring, which may be carried by the casing section and which may be received by a corresponding circumferential recess formed on an outer surface of the connector and/or the hub extension. The sealing ring may have one or more annular grooves on its radially inner face, and the recess may have corresponding circumferential ribs which are received in the grooves. Another option is for the seal to include a labyrinth seal, with formations on facing surfaces of the casing section and the connector and/or the hub extension forming the labyrinth.
- The connector may be formed with or may carry a circumferential oil thrower formation at its radially outer surface.
- Further optional features of the invention are set out below.
- Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:
-
FIG. 1 is a sectional elevation through a turbocharger impeller joined to a shaft by a connector in accordance with an embodiment of the invention; -
FIG. 2 is a close-up schematic view of a seal between a section of a casing of the impeller ofFIG. 1 and a hub extension of the impeller; -
FIG. 3 is a close-up schematic view of a seal between a section of a casing of an impeller and a sleeve portion of a further embodiment of the connector; and -
FIG. 4 shows schematically a sectional elevation of a further embodiment of the connector. - Referring first to
FIG. 1 , analuminium alloy impeller 1 is fitted on to asteel turbocharger shaft 2 by means of aconnector 3. The alloy of which the impeller is made (known in the U.S.A. by the designation “2618A”) has a relatively high strength for use up to a temperature of about 200° C., having a composition of aluminium with about 2.5 wt. % copper and smaller amounts of magnesium, iron and nickel. - The alloy of the
impeller 1 has a coefficient of thermal expansion of about 22.7×10−6/K, and the steel of theshaft 2 has a coefficient of thermal expansion of about 11×10−6/K. The material of theconnector 3 preferably has a coefficient of thermal expansion such that the value of (αc−αs)/(αi−αs) is greater than 0.2, and more preferably greater than 0.3 or 0.4. For example, theconnector 3 may be made of magnesium alloy (coefficient of thermal expansion of about 26×10−6/K), bronze (coefficient of thermal expansion typically of about 18×10−6/K, although as high as 20-21×10−6/K for manganese-bronze), brass (coefficient of thermal expansion of about 18.7×10−6/K) or stainless steel (coefficient of thermal expansion of in the range of 16-17.3×10−6/K). Such alloys can also be resistant to galling with the steel of theshaft 2. - The
connector 3 is of cup-like shape and has anouter surface 14 for connecting to theimpeller 1, a threadedportion 12 with a threadedbore 11 forming the base of the cup, and aflange portion 8 around the mouth of the cup. - The
shaft 2 is formed at its end with a first shoulder 4 surrounding a cylindrical centring portion 5, and a screw-threadedportion 7 of further reduced diameter extending from the end of the centring portion. Theconnector 3 is inserted into a blind central recess formed in the hub extension H, with theouter surface 14 of theconnector 3 frictionally connected to the radially inner surface of the hub extension H. Theflange portion 8 of theconnector 3 engages against a shaft-side end face 9 of the hub extension H to determine the relative axial positions of theconnector 3 and the hub extension H. Theflange portion 8 is engaged on its other side by the shoulder 4 on theshaft 2. The centring portion 5 of the shaft is received in acorresponding centring portion 10 of the connector in a close, but not tight, fit. The threaded bore 11 engages on the screw-threadedportion 7 of the shaft. The threadedportion 12 has a small clearance from the end of the recess. - The
connector 3 is fitted on to the hub extension H by cooling theconnector 3 to cause it to shrink and by heating the impeller to cause the hub extension H to expand, and then inserting theconnector 3 into the central recess of the hub extension H until theflange portion 8 contacts the end face 9 of the hub extension H. On returning from their thermal excursions, theconnector 3 and hub extension H frictionally grip across theouter surface 14 of theconnector 3 and the radially inner surface of the hub extension H. Theouter surface 14 extends over and thereby frictionally contacts most of the axial length of the hub extension H. - The outer diameter of the
flange portion 8 is provided with an oil capture/thrower ring R, which in this embodiment of the invention is machined into theflange portion 8. Another option, however, is to form the ring R as a separate component. - As shown better in
FIG. 2 , asection 15 of the impeller casing and the outer surface of the hub extension H are in close proximity to help provide a rotating oil and pressure seal between theimpeller 1 and the casing. To improve the seal, the hub extension H has arecess 13 on its outer surface which is bounded at one end by theflange portion 8 of the first component of the connector and which receives a sealingring 16 carried by thecasing section 15. To reduce wear between the sealingring 16 and the hub extension H, thecasing section 15 has asmall abutment surface 20 on the shaft side (right hand inFIG. 1 ) of theseal ring 16 and against which the sealingring 16 rests. To provide enhanced sealing, the sealingring 16 hasannular grooves 18 on its radially inner face, and the recess has correspondingcircumferential ribs 17 which are received in the grooves, as described in EP A 1130220. Alternatively, however, the sealing ring can be a plain ring (i.e. without grooves) received in a plain recess (i.e. without ribs). The sealingring 16 co-operates with thecasing section 15 and serves to retain lubricating oil to the shaft side of the assembly and compressed air to the impeller side of the assembly (left hand inFIG. 1 ). The compressed air is contained between the body of theimpeller 1, the hub extension H with itssealing ring 16, and the impeller casing, within which the impeller assembly is mounted for rotation on overhung bearings (not shown). - After the
connector 3 is fitted on to the hub extension H, the screw-threadedportion 7 of theshaft 2 is screwed onto the threadedportion 12 of theconnector 3, therespective centring portions 5, 10 ensuring the shaft aligns with the axis of the impeller. The threads are screwed until opposing surfaces of theflange portion 8 and shoulder 4 come into abutment, which causes the threads to tighten and provides a rotationally fixed connection between theimpeller 1 and theshaft 2. - Advantageously, by forming the
connector 3 from a material having an intermediate coefficient of thermal expansion, the differential thermal forces acting across the frictional connection between theconnector 3 and theimpeller 1 can be reduced relative to a connector formed from the a material having the same coefficient of thermal expansion as that of the shaft. In this way, the tendency for the impeller to “walk” can also be reduced, which allows the impeller to be driven by a higher torque and therefore increases the maximum pressure ratio of the impeller. In addition, by containing the threaded connection between theconnector 3 and theshaft 2 in the central recess of the hub extension H, an axially compact arrangement is achieved. The frictional connection between theconnector 3 and the impeller transmits, in use, substantially all of the torque between theshaft 2 and theimpeller 1. Further, as there is no need to fit a constraining ring of the type described in EP1394387 to the hub extension H, regrinding operations can be avoided during fitting of theconnector 3. - If there is any tendency for the
impeller 1 to “walk”, advantageously this can be monitored by measuring the size of the gap that would open up between theflange portion 8 and the end face 9. For this reason, it is preferred that theflange portion 8 and the end face 9 determine the relative axial positions of theconnector 3 and the hub extension H. Alternative pairs of facing features that could be configured to abut each and thereby determine the relative axial positions (such as the threadedportion 12 and the end of the recess) are less amenable to inspection. -
FIG. 3 is a close-up schematic view of a seal between a section of a casing of an impeller and theflange portion 8 of a further embodiment of theconnector 3. In this case, instead of a seal formed by a sealing ring, the hub extension H andflange portion 8 on one side and thecasing section 15 on the other side have engagingsurfaces 19 carrying respective sets of machined grooves which interlock to form a labyrinth seal. -
FIG. 4 shows schematically a sectional elevation of a further embodiment of the connector. This embodiment is similar to the embodiment ofFIG. 1 except that theshaft 2 has twocentring portions corresponding centring portions portions shaft 2 and the connector are located axially between the engaging pairs of centring portions such that, on each of the shaft and the connector, the respective diameters of the threaded portions and the centring portions decrease towards the impeller. A further difference relative to the embodiment ofFIG. 1 is that the threads are tapered, so that merely screwing the threadedportions impeller 1 and theshaft 2. - While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. For example, in embodiments such as that of
FIG. 4 in which the shaft has acentring portion 5 b which is at the base of the recess, instead of the connector having a centringportion 10 b, the impeller may have a centring portion at the base of the recess that engages with thecentring portion 5 b of the shaft. In another example, the threads carried by the threadedportion 12 of theconnector 3 may be protected by a helicoil formation to prevent damage to the threads of theconnector 3 from the stronger material of theshaft 1. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention. - All references referred to above are hereby incorporated by reference.
Claims (13)
1. A connected impeller and shaft, the impeller having a shaft-side hub extension with a central blind hole recess, the impeller being fitted with a connector which connects the impeller to the shaft, and the impeller being formed of a material having a greater coefficient of thermal expansion than the material of the shaft, wherein: the connector is inserted into the recess to frictionally connect an outwardly facing surface of the connector with a radially inner surface of the hub extension, the frictional connection between the outwardly facing surface of the connector and the radially inner surface of the hub extension transmitting, in use, substantially all of the torque between the shaft and the impeller; and
the connector has a threaded portion carrying a thread which screws onto a corresponding threaded portion of the shaft, such that the connector provides a rotationally fixed connection between the impeller and the shaft;
charaterised in that:
the connector is formed of a material having a coefficient of thermal expansion which is greater than the coefficient of thermal expansion of the material of the shaft, the value of (αc−αs)/(αi−αs) being greater than 0.2 and less than 0.9, where αc is the coefficient of thermal expansion of the connection, αi is the coefficient of thermal expansion of the impeller, αs is the coefficient of thermal expansion of the shaft .
2. (canceled)
3. (canceled)
4. (Canceled)
5. A connected impeller and shaft according to claim 1 , wherein the connector is formed of a material having a greater strength than the material of the impeller.
6. (canceled)
7. A connected impeller and shaft according to claim 1 , wherein the threaded portion of the connector is within the central recess.
8. A connected impeller and shaft according to claim 1 , wherein the connector and/or the impeller has one or more centring portions having respective engagement surfaces which engage with one or more corresponding centring portions of the shaft, the threaded portion of the connector and the centring portions of the connector and/or the impeller being distributed along the impeller axis.
9. A connected impeller and shaft according to claim 1 , wherein the impeller has a casing and the connector and/or the hub extension forms a seal with a section of the casing.
10. A connected impeller and shaft according to claim 1 , wherein the connector is formed with or carries a circumferential oil thrower formation at its radially outer surface.
11. (canceled)
12. (canceled)
13. A turbocharger having the connected impeller and shaft of claim 1 .
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1200403.2 | 2012-01-10 | ||
GBGB1200403.2A GB201200403D0 (en) | 2012-01-10 | 2012-01-10 | Connector |
PCT/GB2012/053082 WO2013104880A1 (en) | 2012-01-10 | 2012-12-11 | Turbocharger having a connector for connecting an impeller to a shaft |
Publications (1)
Publication Number | Publication Date |
---|---|
US20150044047A1 true US20150044047A1 (en) | 2015-02-12 |
Family
ID=45788758
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/370,894 Abandoned US20150044047A1 (en) | 2012-01-10 | 2012-12-10 | Turbocharger having a connector for connecting an impeller to a shaft |
Country Status (8)
Country | Link |
---|---|
US (1) | US20150044047A1 (en) |
EP (1) | EP2802743A1 (en) |
JP (1) | JP6002781B2 (en) |
KR (1) | KR20140113944A (en) |
CN (1) | CN104040116B (en) |
GB (1) | GB201200403D0 (en) |
IN (1) | IN2014KN01595A (en) |
WO (1) | WO2013104880A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105863740A (en) * | 2016-03-24 | 2016-08-17 | 中国北方发动机研究所(天津) | High-reliability turbocharger turbine rotary shaft interlocking type connecting structure |
US20230147254A1 (en) * | 2021-11-11 | 2023-05-11 | Progress Rail Locomotive Inc. | Impeller attach mechanism |
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GB201220300D0 (en) | 2012-11-12 | 2012-12-26 | Cummins Ltd | Turbomachine bearing assembly preloading arrangement |
DE102016100819A1 (en) * | 2015-02-20 | 2016-08-25 | Abb Turbo Systems Ag | coupling device |
KR101872808B1 (en) | 2017-04-28 | 2018-06-29 | 두산중공업 주식회사 | Gas Turbine Rotor Having Control Structure Of Axial Clearance, And Gas Turbine Having The Same |
DE112018003072T5 (en) * | 2017-06-16 | 2020-02-27 | Ihi Corporation | Impeller made of FK for vehicle turbochargers |
CN110094361A (en) * | 2019-04-02 | 2019-08-06 | 中国北方发动机研究所(天津) | A kind of dynamoelectric compressor impeller |
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US20020001522A1 (en) * | 2000-06-28 | 2002-01-03 | Shankar Mukherjee | Compressor wheel with prestressed hub and interference fit insert |
US6948913B2 (en) * | 2002-08-24 | 2005-09-27 | Demag Delaval Industrial Turbomachinery Limited | Turbochargers |
US7374402B2 (en) * | 2002-05-06 | 2008-05-20 | Abb Turbo Systems Ag | Fastening arrangement for an impeller on a shaft |
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JP3129587B2 (en) * | 1993-08-23 | 2001-01-31 | 石川島播磨重工業株式会社 | Centrifugal low-temperature compressor impeller mounting structure |
EP0903465B1 (en) * | 1997-09-19 | 2003-09-03 | ABB Turbo Systems AG | Compressor wheel-shaft connection for high speed turbomachinery |
JP3453302B2 (en) * | 1998-05-07 | 2003-10-06 | 三菱重工業株式会社 | Method of joining TiAl alloy member to structural steel and joining parts |
GB2359863B (en) | 2000-03-04 | 2003-03-26 | Alstom | Turbocharger |
DE102008056058A1 (en) * | 2008-08-04 | 2010-02-11 | Mtu Friedrichshafen Gmbh | Exhaust gas turbo charger, has rotor and compressor rotor coaxially connected via shaft, thread adapter screwed on shaft from side of compressor, and centric recess provided with internal thread fitted at external thread at thread adapter |
GB201122236D0 (en) * | 2011-12-23 | 2012-02-01 | Napier Turbochargers Ltd | Connector |
-
2012
- 2012-01-10 GB GBGB1200403.2A patent/GB201200403D0/en not_active Ceased
- 2012-12-10 US US14/370,894 patent/US20150044047A1/en not_active Abandoned
- 2012-12-11 WO PCT/GB2012/053082 patent/WO2013104880A1/en active Application Filing
- 2012-12-11 IN IN1595KON2014 patent/IN2014KN01595A/en unknown
- 2012-12-11 EP EP12812694.3A patent/EP2802743A1/en not_active Withdrawn
- 2012-12-11 CN CN201280065308.3A patent/CN104040116B/en active Active
- 2012-12-11 KR KR1020147019409A patent/KR20140113944A/en not_active Application Discontinuation
- 2012-12-11 JP JP2014550755A patent/JP6002781B2/en active Active
Patent Citations (3)
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US20020001522A1 (en) * | 2000-06-28 | 2002-01-03 | Shankar Mukherjee | Compressor wheel with prestressed hub and interference fit insert |
US7374402B2 (en) * | 2002-05-06 | 2008-05-20 | Abb Turbo Systems Ag | Fastening arrangement for an impeller on a shaft |
US6948913B2 (en) * | 2002-08-24 | 2005-09-27 | Demag Delaval Industrial Turbomachinery Limited | Turbochargers |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105863740A (en) * | 2016-03-24 | 2016-08-17 | 中国北方发动机研究所(天津) | High-reliability turbocharger turbine rotary shaft interlocking type connecting structure |
US20230147254A1 (en) * | 2021-11-11 | 2023-05-11 | Progress Rail Locomotive Inc. | Impeller attach mechanism |
US11739763B2 (en) * | 2021-11-11 | 2023-08-29 | Progress Rail Locomotive Inc. | Impeller attach mechanism |
Also Published As
Publication number | Publication date |
---|---|
JP6002781B2 (en) | 2016-10-05 |
KR20140113944A (en) | 2014-09-25 |
EP2802743A1 (en) | 2014-11-19 |
WO2013104880A1 (en) | 2013-07-18 |
IN2014KN01595A (en) | 2015-10-23 |
CN104040116B (en) | 2016-06-08 |
GB201200403D0 (en) | 2012-02-22 |
CN104040116A (en) | 2014-09-10 |
JP2015503703A (en) | 2015-02-02 |
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