RU2750220C1 - Turbocharger for charging an internal combustion engine - Google Patents

Abstract

FIELD: mechanical engineering.SUBSTANCE: invention relates to the field of mechanical engineering, in particular to turbochargers for pressurizing consumed air or a combustible mixture with cylinders of internal combustion engines. A turbocharger for pressurizing an internal combustion engine contains a middle housing with oil distribution channels connected to the adapter, in which a rotor shaft is installed on two radial bearings, which are floating rotating bushings, and a thrust bearing, on the consoles of which a turbine wheel and a compressor wheel are mounted, each placed in its own the case. The cover is the rear cover of the compressor casing and the front cover of the middle casing. In addition, it is equipped with a bypass valve with an adapter integrated into the cover, while a strainer is installed in the adapter fixed in the middle housing at the oil inlet to the bearing assembly.EFFECT: elimination of oil carryover through the compressor stage seal.1 cl, 3 dwg

Description

The present invention relates to the field of mechanical engineering, in particular to turbochargers for pressurizing consumed air or a combustible mixture with cylinders of internal combustion engines.

Known turbocharger for pressurization of an internal combustion engine, containing a bearing housing, in which a rotor shaft is installed on radial and thrust bearings, on the consoles of which a turbine wheel and a compressor wheel are fixed, each placed in its own housing, a diffuser installed in the compressor housing, made in the bearing housing oil supply channels and a channel for oil drainage, oil dispensing elements, bearing housing on the turbine side has the shape of a truncated cone with a slope angle of 22 °, and its wall, which forms a channel for oil drainage, is made at an angle of 22 ° <α <90 °, while the center distance between the radial bearings is 56.5 mm (RU 150623 U1, IPC F02B 37/00 (2006.01), F04D 29/05 (2006.01), publ. 20.02.2015).

Also known is an adjustable turbocharger for pressurizing an internal combustion engine, containing a bearing housing, in which a rotor shaft is installed on radial and thrust bearings, on the consoles of which a turbine wheel and a compressor wheel are fixed, each placed in its own housing, a diffuser, a mechanism for regulating the boost pressure, when In this case, the compressor casing is made integral with the diffuser to form an anti-surge cavity, and in the turbine casing there is additionally a bypass channel communicating with the exhaust channel (RU 129996 U1, IPC F02B 37/12 (2006.01), F02B 37/16 (2006.01), F02B 37 / 18 (2006.01), F02D 23/00 (2006.01), F04D 25/04 (2006.01), publ. 07/10/2013).

The closest in terms of the set of essential features and the achieved technical result is a turbocharger for pressurizing an internal combustion engine, containing a bearing housing, in which a rotor shaft is installed on radial and thrust plain bearings, on the consoles of which a turbine wheel and a compressor wheel are fixed, each placed in its own housing, a diffuser, oil supply channels and a channel for oil drainage, oil dispensing elements made in the bearing housing, oil dispensing elements are made in the area of intersection with the oil supply channels on the bearing working surfaces of the bearing housing in the form of a depression in the form of a paraboloid of rotation (RU 134595 U1, IPC F02B 37 / 00 (2006.01), F16C 33/10 (2006.01), publ. 20.11.2013).

The significant disadvantages of these analogs include:

- the lack of constructive measures to exclude oil carryover through the contact seal of the compressor stage into the engine intake tract due to the occurrence of a vacuum in the cavity between the outer rim of the compressor wheel, the compressor housing cover and the sealing ring during operation of the engine with a turbocharger under unsteady conditions, including idle operating modes, when there is no oil flow from the engine, and the lack of oil most often causes breakdowns of turbochargers operating at high speeds;

- ingress of foreign mechanical impurities into the bearing assemblies of turbochargers, which, due to high rotor speeds, causes failure of the turbocharger even with small sizes of foreign objects.

The task was to improve the reliability of the turbocharger.

To solve this problem, a turbocharger for pressurizing an internal combustion engine, containing a middle housing with oil distribution channels connected to the adapter, in which a rotor shaft is installed on two radial bearings, which are floating rotating bushings, and a thrust bearing, on the consoles of which the turbine wheel and the compressor wheel are fixed housed each in its own housing, the cover, which is the rear cover of the compressor housing and the front cover of the middle housing, is additionally equipped with a bypass valve with an adapter integrated into the cover, while a strainer is installed in the adapter fixed in the middle housing at the oil inlet to the bearing assembly.

The set of distinctive features, which is that the turbocharger is additionally equipped with a bypass valve with an adapter integrated into the cover, as well as the installation of a strainer in the turbocharger adapter at the oil inlet to the bearing unit of the strainer, makes it possible to increase the reliability of the turbocharger operation by eliminating oil carryover through compaction of the compressor stage, which occurs due to the rarefaction of air in the cavity between the outer rim of the compressor wheel, the compressor housing cover and the sealing unit at idle, in transient conditions and at low engine speeds, and also prevents the ingress of foreign mechanical impurities into the bearing units of the turbocharger ...

Analysis of known technical solutions for scientific, technical and patent documentation showed that the set of essential features of the proposed solution was not previously known.

The essence of the invention is illustrated by drawings:

fig. 1 - turbocharger for pressurizing the internal combustion engine;

fig. 2 - the same, section A-A in Fig. one;

fig. 3 - the same, view B in Fig. one.

A turbocharger for pressurizing an internal combustion engine comprises a compressor casing 1 and a turbine casing 2, which are fixed to the middle casing 3 by means of bolts and strips. On the middle casing 3 with the help of bolts, the cover 4 is also fixed, made of an aluminum alloy and being both the cover of the casing 3 and the cover of the compressor casing 1.

In the middle casing 3, a rotor shaft 7 is installed in a combined bearing unit, which consists of a thrust bearing 5 and two radial bearings 6, which are floating rotating bushings. On the consoles of the shaft 7 are fixed a turbine wheel 8 located in the turbine housing 2 and a compressor wheel 9 located in the compressor housing 1. An adapter 10 is installed on the body 3, which connects the engine lubrication system with the oil distribution channels 11 of the turbocharger.

To reduce heat transfer between the turbine casing 2 and the middle casing 3, a screen 12 of heat-resistant steel is installed. In the casing 3 there is an oil discharge screen 13, which together with the sealing rings 14 and 15 serves to prevent oil leakage from the cavity of the casing 3 into the flow paths of the compressor and turbine.

In order to optimize the carryover of oil into the engine intake tract through the ring 14 of the compressor stage sealing unit, which occurs due to the vacuum in the cavity (a) (Fig. 1), between the outer rim of the compressor wheel 9, the compressor housing cover 4 and the compressor stage sealing unit at idle, in transient conditions and at low engine speeds, a bypass valve 16 is installed directly on the cover 4 of the compressor housing. The bypass valve is installed by means of an adapter 17 integrated into the cover 4 (Fig. 2). Air intake into the cavity (a) in the above modes is carried out from the engine air cleaner through the square 18 (Fig. 2).

In order to exclude the ingress of foreign mechanical impurities into the bearing assemblies of the turbocharger, an oil strainer 19 is additionally installed between the adapter 10 and the middle housing 3 of the turbocharger (Fig. 3), which eliminates further damage and jamming of the floating bushings of the radial bearings 6, the rotor shaft 7 and the thrust bearing 5 (Fig. 1).

As part of an internal combustion engine, the claimed turbocharger operates as follows.

Under the action of the engine exhaust gases, the turbine wheel 8 through the rotor shaft 7 rotates the compressor wheel 9, while the kinetic energy of the compressor wheel rotation is converted into the work of compressing the air supplied to the engine cylinders.

The bypass valve 16, which is an automatic check valve, when the pressure in the cavity (a) becomes less than 1 bar, it always starts to open and let the "cold" air pass only into the compressor stage, actively cooling the turbocharger parts. This eliminates the carryover of oil from the cavity (a) into the intake tract of the engine. When the air pressure of the compressor wheel reaches 1 bar or more, the bypass valve 16 closes, while there is no need for air to flow through the bypass valve, and the turbocharger continues to work in normal mode. This solution can dramatically improve the reliability of the turbocharger.

Oil on radial bearings 6, thrust bearing 5, as well as in the seal assemblies of the compressor stage and turbine stage, from the lubrication system enters through an additional strainer 19 (Fig. 1, Fig. 3), then through the holes 11 of the middle casing 3 of the turbocharger and holes of floating bushings of radial bearings 6 (Fig. 1).

The engine oil, having worked out in the bearing units and in the sealing units of the compressor and turbine stages, then performs the functions of cooling the middle housing and other parts of the turbocharger and is drained into the crankcase of the internal combustion engine for further cooling in the heat exchanger and purification in the oil filter of the internal combustion engine.

In certain operating modes of the turbocharger, oil seeping through the compressor stage seal 14 is retained by the oil screen 15 and returns to the engine oil sump.

The claimed features of the technical solution can dramatically improve the reliability, technical and economic performance of the turbocharger.

The turbocharger device for pressurizing air into an internal combustion engine meets the requirement of industrial applicability and is possible for implementation on standard technological equipment.

Claims (1)

A turbocharger for pressurizing an internal combustion engine, containing a middle housing with oil distribution channels connected to the adapter, in which a rotor shaft is installed on two radial bearings, which are floating rotating bushings, and a thrust bearing, on the consoles of which a turbine wheel and a compressor wheel are mounted, each located in its housing, the cover, which is the rear cover of the compressor housing and the front cover of the middle housing, characterized in that it is additionally equipped with a bypass valve with an adapter integrated into the cover, while a strainer is installed in the adapter fixed in the middle housing at the oil inlet to the bearing assembly.

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