TURBOCHARGER HOUSING

Abstract

A turbocharger housing is split lengthwise and has two housing halves, which in the assembled state sectionally form a bearing housing, a turbine housing, and a compressor housing. The turbocharger housing contains at least one fluid chamber, which is arranged in the bearing housing and/or in the turbine housing and/or in the compressor housing of at least one of the two housing halves. The fluid chamber contains a plurality of raised webs, which are disposed to influence the fluid flow.

Description

The present invention relates to a turbocharger housing, wherein the turbocharger housing comprises a compressor housing and a turbine housing, together with a bearing housing.

Turbochargers generally serve to improve the efficiency of an internal combustion engine and thereby to boost its power output. For this purpose the turbocharger comprises a turbine with a turbine rotor and a compressor with a compressor wheel, the two rotors being arranged on a common rotor shaft. Here the turbine rotor is driven via an exhaust gas mass flow of a connected internal combustion engine and in turn drives the compressor wheel. Here the compressor compresses the aspirated air and delivers this to the internal combustion engine. The rotor shaft is supported here in a bearing housing of the turbocharger. The turbine rotor of the turbine is furthermore arranged in a turbine housing and the compressor wheel of the compressor is arranged in a compressor housing. The bearing housing, the turbine housing and the compressor housing together form the turbocharger housing. The turbine rotor, the compressor wheel and the rotor shaft together form the rotor runner.

In operation on the internal combustion engine or a connected engine, such a turbocharger has to fulfill diverse requirements. One of these requirements is to absorb the high temperatures occurring, which can be generated in the turbocharger housing due to the hot exhaust gas mass flow.

The usual design of the turbocharger here provides for individual housings, each of a material matched to the temperature prevailing there.

Here the compressor housing is usually made of aluminum, whilst the bearing housing is made of grey cast iron and may additionally be of water-cooled construction. The turbine housing is in turn generally made from materials having a high nickel content, owing to the high temperatures that prevail in this area. Because of the various materials matched to the individual housings, these housings are formed as separate parts, which have to be connected together and at the same time sealed off from one another. Such a turbocharger is therefore costly to manufacture and assemble.

A turbocharger housing which avoids the aforementioned disadvantages is disclosed, for example, in German patent application 10 2009 053 106.8. In this case the turbocharger housing is designed at least partially or completely divided into at least two parts in a longitudinal direction, that is to say in the longitudinal direction of the rotor shaft, the portion of the turbocharger housing divided in a longitudinal direction in each case comprising a part of the compressor housing, a part of the bearing housing and/or a part of the turbine housing. Here the turbocharger housing may be manufactured from aluminum, for example, or an aluminum alloy or another metal or metal alloy, or another suitable material.

The division in a longitudinal direction, in the present example referred to as a horizontal or substantially horizontal division, firstly affords direct advantages. For example an automated pre-assembly of the rotor runner, including the two rotors, such as the compressor wheel and the turbine rotor, and the rotor shaft, is possible. This also clearly facilitates subsequent fitting in the turbocharger.

In addition, provision is made for an additional temperature control, for example cooling and/or heating, of at least a part of the turbocharger housing, for example the turbine housing, the bearing housing and/or the compressor housing. For this purpose a fluid or temperature control jacket having a fluid core is provided. As shown in FIG. 1, for example, this fluid jacket spans the bearing housing portion and the turbine housing portion of the turbocharger housing. A cooling medium flows through the fluid or temperature control jacket having a fluid core, also referred to as a fluid chamber. This additionally affords cooling of the turbine housing and the bearing housing.

The turbocharger housing here has the advantage that the rotor runner, that is to say the rotors on the rotor shaft and the bearing arrangement of the rotor shaft, can be pre-assembled and then inserted complete into the housing halves. In addition, the rotor runner can be subjected to operational balancing beforehand, without previously having to fit it in the turbocharger housing.

The fluid chambers incorporated into a turbocharger housing are often very flat, however, in order to save weight and overall space. The flow behavior of the cooling medium thereby certainly often suffers, resulting in irregular flows through the fluid chamber and hence uneven cooling. In extreme cases it can happen that a part of the turbocharger housing to be cooled is poorly cooled, if at all, during operation of the turbocharger.

The object of the present invention is to provide an improved turbocharger housing, which does not have the aforementioned disadvantages.

This object is achieved in a turbocharger housing of generic type having the characterizing features of claim 1.

In this turbocharger housing at least one portion, formed from a turbine housing, a bearing housing and/or a compressor housing, is divided in a longitudinal direction into two housing halves, which in the assembled state in portions form a bearing housing, a turbine housing and a compressor housing. Here at least one fluid chamber, which in operation is charged with a cooling medium, is arranged in the bearing housing and/or in the turbine housing and/or in the compressor housing of at least one of the two housing halves. The fluid chamber here is characterized in that it comprises a plurality of raised webs, which act as restrictions for the cooling medium, so that the cooling medium forms flows, which run in various directions. This serves to prevent isolated areas of the turbocharger being insufficiently cooled or even not cooled at all.

Advantageous embodiments and developments of the invention are characterized in the dependent claims and the subsequent description of the figures.

The invention is explained in more detail below with reference to the drawing, in which:

FIG. 1 shows a sectional view of a housing half of a turbocharger housing, augmented by the raised webs provided according to the invention;

FIG. 2 shows a top view of a housing half (detail FIG. 2A), in lateral section (detail FIG. 2B) and in cross section (detail FIG. 2C);

FIG. 3 shows an outer part of a turbine housing as part of a turbocharger housing;

FIG. 4 shows a side view of the outer part according to FIG. 3;

FIG. 5 shows a gasket for assembly of the two housing halves of the turbocharger housing according to the invention.

Unless otherwise stated, the same or functionally equivalent elements and devices have been provided with the same reference numerals in all figures. The representation of the turbocharger shown in the following figures is moreover purely schematic, not to scale and highly simplified.

FIG. 1 is a sectional view through a housing half 10 of a turbocharger housing 12 according to a first embodiment of the invention, the housing half 10 here being shown from the gasket side. In FIG. 1 a recess 50 or groove for receiving a sealing device is shown as an example.

In this example the turbocharger housing 12 here comprises a bearing housing 14, a turbine housing 16 and a compressor housing 18, all three housings being united to form one housing 12. In the case shown, a part of the invention resides in the initial notion of uniting all three housings, 14, 16, 18, for example, and producing these as one part, for example from an integral casting. For assembling the rotor runner and for machining the inner working faces, a division is furthermore defined, through which the interior of the housing 12 can be opened up. According to the invention this division is made in a longitudinal direction, that is to say in the direction of the axis of the rotor shaft, the plane of division lying in one or more planes in which the rotor shaft 26 lies, or which are arranged substantially parallel to the rotor shaft 26. Here the rotational position of the plane of division about the axis of the rotor shaft may be selected, as required, at an angle of between 0° and 360°. In principle the entire turbocharger housing 12, comprising the compressor housing 18, the turbine housing 16 and the bearing housing 14, may be of longitudinally divided design. It is also possible, however, to design just one portion of the turbocharger housing 12 with a longitudinal division, the portion comprising a rotor housing 16, 18 and/or the bearing housing 14.

As shown in FIG. 1, the turbine housing 16, the bearing housing 14 and the compressor housing 18 may be formed from two housing halves 10 each in one piece. In this case in FIG. 1 the turbocharger housing 12 is divided into two housing halves 10 in a continuous plane, in which the axis of the rotor shaft 26 lies. Here a first housing half 10, comprising the turbine housing 16, the bearing housing 14 and the compressor housing 18, for example, forms the so-called upper part, and a second housing half, comprising the turbine housing 16, the bearing housing 14 and the compressor housing 18, forms the so-called lower part. FIG. 1 here shows a housing half 10 from the gasket side. Here this housing half 10 is fastened, for example bolted, to the other housing half (not shown). For this purpose, in the embodiment shown in FIG. 1, multiple bores 20, in this case six bores, for example, are provided for bolting the two housing halves together. In principle, however, any other form of fastening the housing halves may also be provided.

The division in a longitudinal direction firstly affords direct advantages. For example, an automated pre-assembly of the rotor runner, including the two rotors, such as the compressor wheel 22 and the turbine rotor 24, and the shaft 26, is possible. This also clearly facilitates subsequent fitting in the turbocharger. In addition, if provision is made for an additional temperature control, for example cooling and/or heating, of at least a part of the turbocharger housing 12, for example the turbine housing 16, the bearing housing 14 and/or the compressor housing 12, a fluid or temperature control jacket 28 having a fluid core may be provided. In the example in FIG. 1 this fluid jacket 28, for example, spans the bearing housing portion 14 and the turbine housing portion 16 of the turbocharger housing 12 without any back taper, since in this example the turbine housing 16 and the bearing housing 14 are to be additionally cooled, for example. This means, for example, that a sand core for producing the fluid jacket 28 does not have to be assembled and bonded together from several pieces.

A further advantage is that at least one half or the overall turbocharger housing 12 can be integrated into the engine block and/or the cylinder head of a connected engine. In this case, for example, the lower part of the turbocharger housing 12 can be integrated into the engine block and the upper part into the cylinder head, or vice versa.

In FIG. 1 the shaft 26, on which the turbine rotor 24 and the compressor wheel 22 are provided, is supported in the bearing housing portion 14 of the turbocharger housing 12. The turbine rotor 24 here is arranged in the turbine housing portion 16 and the compressor wheel 22 in the compressor housing portion 18. The shaft 26 furthermore comprises a radial bearing arrangement 30 and optionally also an axial bearing arrangement 32.

In the turbocharger according to the invention, which through the division forms two bore halves, for example, the bearing arrangement 30 is fitted, axially braced, for example by way of sprung collar portions 34.

In FIG. 1 the shaft 26 is supported via the radial bearing arrangement 30 and the axial bearing arrangement 32. The radial bearing arrangement 30 here comprises a through-sleeve 36, which at each of its two ends forms a slide bearing portion 38 for supporting the shaft 26 in a radial direction. Here the sleeve 36 is pushed on to the shaft 36, the shaft 26 forming a step with a stop for the sleeve 36. At the other end of the sleeve 36 an axial bearing arrangement 32 is provided, the axial bearing arrangement 32 comprising at least one axial bearing in the form of an axial bearing disk 40. In addition an oil baffle plate 42 is arranged on the axial bearing disk 40 here. Furthermore a layer 44 composed of at least one or more coatings of heat-resistant or temperature-resistant, elastic material, such as a polymer, an elastomer and/or a hard rubber, for example, is additionally arranged on the outside of the sleeve 36.

A sleeve element 46 is also provided on the outside of the layer 44 of the elastic, temperature-resistant material. The sleeve element 46 here is made, for example, of metal, for example steel. Alternatively the elastic, temperature-resistant material may also be dispensed with and instead the sleeve element 46 may be provided directly on the outside of the sleeve 36 (not shown), or the sleeve 36 may optionally be designed so that it functions not only as a radial bearing arrangement 30 but also as a sleeve element 46 (not shown).

In the example shown in FIG. 1 the sleeve element 46 comprises a collar portion 34 at each of its two ends. Here at least one or both of the collar portions 34 of the sleeve element 46 is of sprung design, allowing it to be clamped between two stops or mounts 48 of the turbocharger housing 12. On or both collar portions 34 may equally well be unsprung, that is to say of rigid design and inserted between the two mounts 48, or alternatively they may also be screw-fastened to the mounts 48 on one or both sides. Alternatively at least one of the sprung collar portions 34 may likewise be additionally fastened to the respective mount 48, for example by bolting. Here one or both collar portions 34 may be integrally connected to the sleeve element 46 or fastened thereto as a separate part (not shown). The bearing arrangement 30, in this case the radial bearing arrangement 30, comprising the sleeve 36 and the elastic layer 44, is axially fixed or braced in the turbocharger housing 12, that is to say the two housing halves 10 of the turbocharger housing 12 via the two collar portions 34 of the sleeve element 46.

Here at least one collar portion 34 may also additionally be led out of the oil chamber, as in FIG. 1 on the turbine side, and may assume further functions as a heat shield. One or both collar portions 34, however, may also remain inside the oil chamber, such as the collar portion 34 of the sleeve element 46 on the compressor side. In addition such a bearing arrangement 30 has the advantage that it can be preassembled in its entirety and can therefore be operationally balanced without the enclosing housing, for example.

The radial bearing arrangement 30 and the axial bearing arrangement 32 in FIG. 1 are merely one example of a bearing of the shaft 26 in a radial and an axial direction. In principle the shaft 26 in the turbocharger housing 12 according to the invention may comprise any other radial bearing arrangement and/or axial bearing arrangement. Thus the sleeve 36, for example, may also be replaced by two radial slide bearings (not shown), the two slide bearings, for example, alternatively in addition comprising a spacer sleeve, or the sleeve element 46 on its inner side comprising a mount for one or each of the two slide bearings (not shown). Besides slide bearings, non-contact bearings such as magnetic bearings and rolling bearings, for example, may also be provided for radial and/or axial support. The invention is not confined to the examples of bearing arrangements shown and described.

In the fluid chamber 28 represented in FIG. 1, two raised webs 6, provided according to the invention, are drawn in, which have a longitudinal extent in the axial direction of the rotor shaft. The raised webs 6 drawn in FIG. 1 have a height H, which extends from one edge of the fluid chamber 28 to the edge of the fluid chamber 28 situated opposite this edge and which therefore corresponds to the height of the fluid chamber 28 at this point.

FIG. 2 in its first detail drawing 2A shows a top view of one of the housing parts 10 and 11 with a fluid chamber 28 and a plurality of raised webs 6 arranged therein. When the fluid chamber 28 is being charged with a cooling medium (in the operation of a ready fitted turbocharger having the turbocharger housing according to the invention), the raised webs 6 act as restrictions for the cooling medium; accordingly turbulences and flows running in various directions form in the cooling medium. This is precisely what is intended according to the invention, since it serves to prevent isolated areas of the turbocharger being insufficiently cooled or even not cooled at all. Such deficiencies would in fact result in premature damage to the turbocharger, or they would at least adversely affect its service life in the long term.

The detail FIG. 2B shows the housing half in detail FIG. 2A in a lateral section along the section line A-A in detail FIG. 2A. Here too, the raised webs 6 can again be seen. The detail FIG. 2C shows the housing half represented in the detail FIG. 2A in cross section along the section line B-B in FIG. 2A. It is also shown here that the raised webs 6 need not necessarily have the height H previously described, which extends from one edge of the fluid chamber 28 to the edge situated opposite this edge, but that the raised webs 6 may also be of a lesser height. This is clearly indicated by the reference symbol H′ in the detail FIG. 2C. The detail FIG. 2A also shows two connection points A, via which in operation the cooling medium can be delivered to and led off from the turbocharger again.

FIG. 3 representing an outer part of the turbine housing 16 of a turbocharger with the two housing parts 10 and 11 (at least partially represented) shows a possible positioning of the raised webs 6 and the resulting flow behavior of the cooling medium illustrated by arrows. Also shown is one of the connections A already mentioned.

FIG. 4 in a side view shows the outer part represented in FIG. 3 together with some of the raised webs 6 and the connections A.

FIG. 5 shows a gasket 4 of the type that may be used in assembling the two housing halves 10 and 11 of an inventive turbocharger housing of a turbocharger. Besides various other openings of no interest here, the gasket 4 has a number of cutouts 4a, for example in the form of bores or punched holes, in the area in which it separates the fluid chambers 28 of the two housing halves 10 and 11 from one another. As the cooling medium is thereby allowed to pass from one housing part 10 or 11 into the other housing part 11 or 10, turbulences of the cooling medium occur at the cutouts 4a, which then also, as already described with regard to the raised webs 6, promote a uniform cooling of the components to be cooled.

Claims

1-6. (canceled)

7. A turbocharger housing, comprising:

at least one portion being divided in a longitudinal direction into two housing halves, said two housing halves in an assembled state in portions form a bearing housing, a turbine housing and a compressor housing; and

at least one fluid chamber for receiving a cooling medium and disposed in at least one of said bearing housing, said turbine housing or said compressor housing of at least one of said two housing halves, said fluid chamber having a plurality of raised webs, for forming flows of the cooling medium running in various directions.

8. The turbocharger housing according to claim 7, wherein at least one of said raised webs has a height being equal to a height of said fluid chamber at a point where said one raised web is situated.

9. The turbocharger housing according to claim 7, wherein at least one of said raised webs has a height being less than a height of said fluid chamber at a point where said one raised web is situated.

10. The turbocharger housing according to claim 7, further comprising connections, via said connections the cooling medium can be delivered to and led off from said fluid chamber.

11. The turbocharger housing according to claim 7, further comprising a gasket disposed between said two housing halves, said gasket in an area where said fluid chamber extends over both of said two housing halves has at least one cutout formed therein, via which the cooling medium is able to flow from a first of said two housing halves into a second of said two housing halves.

12. The turbocharger housing according to claim 11, wherein said cutout is one of a plurality of cutouts formed in said gasket.

13. The turbocharger housing according to claim 12, wherein said cutouts have are selected from the group consisting of bore holes and punched holes.