DE102013114626A1 - Trap bearing for turbocharger - Google Patents

Abstract

Fanglager for exhaust gas turbocharger, which is located between the bearing points on the rotatably mounted shaft which connects the compressor wheel with the turbine wheel. Optionally, the safety bearings can also be located outside the bearings on the shaft. As a further possibility, the safety bearings can be located outside the wheels on the turbine shaft extension and on the compressor shaft extension. The catch bearing can be located at any axial or radial position of the shaft.

Description

TECHNICAL AREA

The invention relates to the field of exhaust gas turbochargers of supercharged internal combustion engines.
It relates to a bearing of the shaft of an exhaust gas turbocharger and an exhaust gas turbocharger with such a shaft bearing.

STATE OF THE ART

Exhaust gas turbochargers are used to increase the performance of internal combustion engines. In this case, the exhaust gas turbine of the exhaust gas turbocharger is charged with the exhaust gases of the internal combustion engine and their kinetic energy used for sucking and compressing air for the internal combustion engine. The impellers of the turbine and the compressor are connected to each other via a shaft mounted in a bearing housing shaft.

Exhaust gas turbochargers include a compressor wheel and a turbine wheel, which are connected via a rotatably mounted in a bearing housing shaft. Generally there are two radial bearings and one thrust bearing. The dominant design is that the bearings are located in a bearing housing between the compressor wheel and the turbine wheel.

In case of imbalance in the turbine or compressor wheel, the shaft bends through. The deflection can become inadmissible with extreme imbalance. This leads to plastic deformation or breakage of the shaft.

It is known that catch bearings are used in magnetic bearings. Active magnetic bearings require a constant power supply and have to secure in case of power outages or failures of the control a mechanical fishing camp, usually consisting of a loose ball or plain bearings. Thus, a backup bearing is an inherent part of a magnetic bearing and ensures the function of the bearing of the rotor in case of failure of an auxiliary system (power supply).

PRESENTATION OF THE INVENTION

The object of the invention is to provide a shaft bearing for an exhaust gas turbocharger, which limits the deflection of the shaft to a subcritical mass at high unbalance and thus prevents critical deformation and breakage of the shaft.

The object is achieved with a catch bearing on the rotatably mounted shaft of an exhaust gas turbocharger.

According to one embodiment of the invention, the backup bearings are located between the radial bearing points on the rotatably mounted shaft which connects the compressor wheel with the turbine wheel.

The invention relates to used in turbochargers sliding and rolling bearings. The safety bearing prevents or reduces the deflection of the shaft in the event of high unbalance forces, as occurs in the blade bursting of radial turbines. The shaft is guided during and after the blade loss until the rotor has degraded by friction in the bearings the remaining rotational energy and comes to a standstill. This prevents that the shaft breaks due to the deflection and axially exits.

Optionally, the catch bearing can also be located outside of the bearings or wheels in any axial or radial position of the shaft.

Further advantages emerge from the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail with reference to drawings. Hereby shows:

1 Shaft bearing of a turbocharger according to the prior art, and

2 an inventive catch bearing for exhaust gas turbocharger.

WAY FOR CARRYING OUT THE INVENTION

1 shows a shaft bearing of a turbocharger according to the prior art. The two wheels, the compressor wheel 10 and the turbine wheel 20 , are via a rotatably mounted shaft 30 connected to each other, being at the shaft bearings 40 . 45 , generally two radial bearing points and a thrust bearing point, are located. The bearings 40 . 45 can be found in a bearing housing between compressor wheel 10 and turbine wheel 20 are located.

In case of imbalance in the turbine or compressor wheel, the shaft bends through, with the deformation of the shaft is exaggerated for clarity in the figure. The deflection can become impermissibly large with extreme unbalance, which can lead to plastic deformation or to the break of the wave.

2 shows a shaft bearing for exhaust gas turbocharger with a novel catch storage. The safety bearing is located according to an embodiment between the bearings 50 on the rotatably mounted shaft 30 , which connects the compressor wheel with the turbine wheel.

A catch bearing between the radial bearing points limits the deflection to a subcritical mass in the event of high imbalance. Critical deformations and a break of the wave are thereby prevented.

Optionally, according to further embodiments of the invention, the fishing camps can 52 . 53 also outside the bearings 40 . 45 on the shaft 30 optional, on the compressor side between the compressor-side bearing point 40 and the adjacent compressor wheel 10 and / or turbine side between the turbine-side bearing 45 and the adjacent turbine wheel 20 ,

Optionally, according to further embodiments of the invention, the fishing camps can 54 . 51 outside the wheels on a turbine-side shaft extension 31 and / or on a compressor-side shaft extension 32 are located. The two wave extensions 31 . 32 are in the 2 in the alternative indicated.

The one or more catch bearings can thus be according to the invention in each case at any axial or radial position of the shaft.

The inventive fishing camps can be applied analogously in other storage structures.

LIST OF REFERENCE NUMBERS

10

compressor

20

turbine

30

wave

31

Shaft extension, turbine side

32

Shaft extension, compressor side

40, 45

bearings

50

Fishing camp, between campsites

51, 54

Safety bearing, outside the wheels

52, 53

Safety bearings, outside the bearings

Claims (7)

Shaft bearing of a pair of wheels, a compressor wheel ( 10 ) and a turbine wheel ( 20 ), comprehensive exhaust gas turbocharger, with arranged between the wheels bearings ( 40 . 45 ), characterized in that at least one fishing camp ( 50 . 51 . 52 . 53 . 54 ) on the shaft ( 30 ) is located. Shaft bearing of an exhaust gas turbocharger according to claim 1, wherein at least one safety bearing ( 50 ) between the depositories ( 40 . 45 ) on the shaft ( 30 ) is located. Shaft bearing of an exhaust gas turbocharger according to claim 1, wherein at least one safety bearing ( 52 . 53 ) between one of the depositories ( 40 . 45 ) and the adjacent impeller on the shaft ( 30 ) is located. Shaft bearing of an exhaust gas turbocharger according to claim 3, wherein both turbine side between a turbine-side bearing ( 45 ) and the turbine wheel ( 20 ) as well as on the compressor side between a compressor-side bearing ( 40 ) and the compressor wheel ( 10 ) at least one safety bearing ( 52 . 53 ) is located. Shaft bearing of an exhaust gas turbocharger according to claim 1, wherein at least one safety bearing ( 51 . 54 ) outside an impeller on a turbine-side or compressor-side shaft extension ( 31 . 32 ) is located. Shaft bearing of an exhaust gas turbocharger according to claim 5, wherein both outside the turbine wheel ( 20 ) on the turbine side as well as outside the compressor wheel ( 10 ) at the compressor-side shaft extension ( 31 . 32 ) at least one safety bearing ( 51 . 54 ) is located Exhaust gas turbocharger comprising a shaft ( 30 ) and a compressor wheel arranged on the shaft ( 10 ) and arranged on the shaft turbine wheel ( 20 ), comprising a shaft bearing according to one of claims 1 to 6.

Images