Classifications

• • 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
  • 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

Definitions

• the invention relates to a rotor of a charging device, in particular of an exhaust gas turbocharger having the features of the preamble of claim 1 and a method having the features of the preamble of claim 9.
• Turbochargers comprise a turbine wheel driven by the exhaust gas stream of the internal combustion engine, which in turn drives a compressor wheel connected to the intake tract of the internal combustion engine.
• the compressor increases the pressure, whereby more oxygen enters the intake system and a larger amount of fuel can be injected, resulting in an increase in power of the internal combustion engine.
• a shaft connects the turbine wheel to the compressor wheel, which together form a rotor.
• turbochargers can reach speeds of over 250,000 rpm.
• the compressor wheel and / or the turbine wheel are stretched radially and axially shortened due to the centrifugal forces, which can set a changed imbalance.
• the whistling noise causing unbalance can continue to lead to a complete failure of the turbocharger and cause damage to the engine.
• EP 1 502 008 B1 discloses a rotor of an exhaust gas turbocharger whose shaft mounted in bearings of a housing connects the wheels, a turbine wheel and a compressor wheel.
• the impeller is frictionally mounted on the shaft with a hub extension with a central recess and with a screwed from the side onto the shaft bushing.
• the one sealing and Holding sleeve is externally provided with a compression sleeve, which is connected by pressing or shrinking with the hub process.
• the object of the invention is to propose a construction which ensures cost-effective manufacture of the rotor, including a process-reliable and at the same time fatigue joining process of all components of the rotor.
• the hub of the impeller form an axially projecting hub extension with an inner receiving profile, in which an end-side shaft portion of a guide pin of a tool positively engages, which is associated in particular with a clamping device.
• the turbine and compressor wheel of the rotor is preferably made of Inconel or a comparable high temperature resistant material in a precision casting process.
• a rework is carried out in several stages before the wheels are integrally connected to the shaft of the rotor to form a unit. This is followed by a finishing of the rotor, in which at least individual components of the rotor, in particular with a mechanical, such as cutting and turning process, refined, in order to achieve optimum running quality of the rotor.
• the clamping device Due to the positive engagement of the guide pin in the receiving profile of the hub extension and the frictional holding of the shaft and the impeller by the clamping device during the cohesive bonding and finishing these components are optimally centered and fixed. Furthermore, a cost-effective production or assembly of all components of the rotor can be realized. Advantageously, all components of the rotor centered and fixed simultaneously with the clamping device and associated guide pin. In addition, the length of the hub extension can advantageously be shortened by the inventive combination of the clamping device, which surrounds the hub extension on the outside, and the guide pin, which engages positively in the hub process.
• the invention achieves an improved positioning, in particular centering or coaxiality, as well as a right-angled orientation of the wheels relative to the shaft, before they are connected in a material-locking manner and subsequently finished.
• tighter manufacturing and positional tolerances can advantageously also be maintained, which have a favorable effect on the operation of the exhaust-gas turbocharger, in which speeds of up to 250,000 rpm are established.
• the clamping device according to the invention in conjunction with the guide pin causes a secure positive and non-positive connection of all components of the rotor for the realization of a task-oriented, process-reliable joining process.
• the measure according to the invention withstands a high introduction of force or introduction of torque and thus favors the cohesive connection of the shaft to the wheels and a mechanical finishing of the rotor.
• the invention provides, in particular for runners with a RaAx turbine wheel (radially and axially irradiated turbine wheel) an effective solution to the previous clamping problem.
• a trained as a polygonal profile receiving profile is introduced, in which engages the guide pin, wherein the outer contour of the pin corresponds to the receiving profile of the hub extension.
• a receiving profile is advantageously a hexagonal profile, where alternatively also a multi-tooth profile can be used.
• the hub extension on the outside forms a cylindrical or profiled, in particular designed as a hexagon centering approach, which engages the clamping device.
• a radial play of ⁇ 0.15 mm is provided between the guide pin and the inner receiving profile of the hub extension, with a preferred radial clearance of 0.1 mm.
• the invention includes a clamping device which comprises a plurality of circumferentially distributed, adjustable in the radial direction, cooperating with the hub extension jaws.
• a cohesive connection of these components is provided after previously the shaft was inserted or pressed into the receptacle of the hub.
• a friction welding is preferably suitable, in which sets a desired, the joining association improving volume shrinkage between the hub and the shaft during cooling after welding.
• friction welding for example, an electron beam welding, soldering or gluing is recommended in order to connect the shaft and the wheels in a permanently bonded manner.
• a further advantageous structural embodiment of the inventive concept provides to design the hub extension with a length S of ⁇ 3 mm, wherein preferably a length S of 2 mm is provided. Furthermore, the hub extension has a wall thickness Z of ⁇ 3 mm, wherein a preferred dimension Z is 2 mm.
• the hub extension is thus significantly shorter compared to previous solutions, which advantageously reduces the use of materials of the costly, temperature-stable material of the wheels.
• a further saving of material is achieved in that the receptacle, which is preferably designed as a bore, extends over the length of the hub extension into the impeller. In addition to a cost advantage, these measures cause a significant weight reduction of> 3 grams for each impeller. Due to the weight-optimized wheels turns in the operating state of the exhaust gas turbocharger a improved rotor dynamics, which improves the response and thus the efficiency of the exhaust gas turbocharger.
• the invention provides the ability to characterize the impeller with a mark indicating the material from which the impeller is made. To avoid an imbalance, the material marking is done centrally on the hub. Preferably, a letter is provided for identification within the receiving profile of the hub process.
• a method for permanent assembly and for finishing a rotor which comprises a shaft with a turbine wheel and a compressor wheel of a charging device, in particular an exhaust gas turbocharger, the method being characterized by the following steps. First, an axial positive mounting of the shaft takes place in a receptacle of the hub of the respective impeller.
• a guide pin is inserted into a running as a polygonal profile receiving profile of an axially projecting hub extension of the hub of the impeller.
• the impeller is aligned with at least one of the hub extension of an impeller enclosing clamping device in conjunction with preferably three mutually spaced clamping jaws.
• the hub extension is frictionally held via three further clamping jaws of the clamping device, which are alternately arranged between the first clamping jaws, wherein the hub extension is deformed up to a permanently elastic range.
• the clamping device causes a fixation, which withstands both a force and / or torque introduction during a cohesive connection of the shaft with the wheels and a mechanical finishing of the rotor.
• Figure 1 is an impeller in a side view.
• FIG. 2 shows the impeller according to FIG. 1 in front view
• FIG. and FIG. 3 shows a schematic structure of a rotor consisting of a shaft, to which an impeller is assigned at each end.
• FIGs 1 and 2 show in simplified representations designed as an impeller impeller 1 '.
• the impeller 1 ' is part of a rotor 2 shown in Figure 3, which comprises two axially spaced impellers 1', 1 "which are connected by a shaft 3.
• a hub 4 of the rotor 2 includes on one side an axially projecting hub extension 5 with a blind hole-like
• the hub extension 5 on the outside forms a centering lug 7, which likewise advantageously forms a polygonal profile
• the receiving profile 6 introduced into the hub extension 5 extends over a length S 2 which exceeds a length S 1 of the hub extension and continues is introduced into the impeller V via an end-face plane surface 10.
• both the receiving profile 6 and the centering projection 7 are formed as hexagonal profiles
• the hub extension 5 has a length Si of ⁇ 3 mm and a wall thickness Z of ⁇ 2 mm shown in Figure 2, the receiving profile 6 of the hub extension 5 includes a marking 8, the d indicates the material from which the impeller V is made.
• FIG. 3 shows the rotor 2, which is part of an exhaust-gas turbocharger not shown in greater detail in FIG.
• One of the wheels 1 ', 1 " is designed as a turbine wheel and the other wheel as a compressor wheel 3.
• the shaft 3 connecting both wheels 1', 1" is rotatably mounted in a housing of the exhaust gas turbocharger.
• the shaft 3 is in took 13 of the hubs 4 of the rotor 1 ', 1' used.
• Symmetrically circumferentially distributed, in particular hydraulically adjustable clamping jaws 12 of the clamping device 1 1 are based non-positively on the spigot 7 of the hub extension 5 from the impeller V from. Furthermore, a guide pin 9 is inserted with a profiled outer profile in a corresponding receiving profile 6 of the hub extension 5.
• the clamping of the hub extension 5 is preferably carried out in two steps. First, a centering with, for example, three clamping jaws 12 is provided before a fixation takes place with three other clamping jaws 12, wherein at the same time the hub extension 5 can be deformed into an elastic range. By means of a cohesive connection then the shaft 3 and the hub 5 of the impeller V are permanently connected by a friction welding. Finally, a mechanical finishing of the rotor 2 can take place before the clamping device 1 1 and the guide pin 9 are removed.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Supercharger (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=48576392

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Cited By (3)

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Citations (12)

Family Cites Families (2)

• 2012
  • 2012-07-24 DE DE102012212990.1A patent/DE102012212990A1/de not_active Ceased
• 2013
  • 2013-05-29 WO PCT/EP2013/061035 patent/WO2014016016A1/fr not_active Ceased

Patent Citations (12)

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