DE102016209149A1 - Bearing unit for an exhaust gas turbocharger or an exhaust gas turbine and storage with such a storage unit - Google Patents

Abstract

The invention relates to a bearing unit for an exhaust gas turbocharger or an exhaust gas turbine - with at least one bearing inner ring; - With at least two bearing outer rings; - Having at least two rows of rolling elements comprising a first row of rolling elements in the region of a first axial end of the bearing unit between a first of the two bearing outer rings and the at least one bearing inner ring and a second row of rolling elements in the region of a first axial end opposite the second axial end of the bearing unit between a second of the both bearing outer rings and the at least one bearing inner ring; - With an intermediate piece which is at least partially positioned in the axial direction between the two bearing outer rings. The bearing unit according to the invention is characterized in that each bearing outer ring is supported elastically with respect to the intermediate piece in the axial direction, each with at least one spring element.

Description

The present invention relates to a bearing unit for an exhaust gas turbocharger or an exhaust gas turbine and a bearing of an exhaust gas turbocharger or an exhaust gas turbine.

The bearing of the turbine shaft in an exhaust gas turbocharger or an exhaust gas turbine, which is arranged in the exhaust stream, in particular a motor vehicle, is a neuralgic component, because due to the high speeds of the turbine shaft often more than 100,000 revolutions per minute and due to the high temperature stress caused by the high exhaust gas temperatures, the bearing unit is exposed to a considerable vibration load and thermal stress. Particularly unfavorable are the significant speed spread and the temperature variations in the bearing unit, which often require passing through resonance speeds and the compensation of widely varying thermal losses.

In view of the better efficiency, rolling bearings are preferred in generic bearing units, which, however, are combined in particular with a vibration damping in the form of Quetschöldämpfern. If, accordingly, an oil film or oil ring is provided radially outside of the bearing outer ring of such bearings, the bearing outer ring has no defined rotational position within the housing of the exhaust gas turbocharger or the exhaust gas turbine more, but can rotate more or less in the circumferential direction relative to the housing and with respect to the turbine shaft. The co-rotation of the bearing outer ring can cause wear on the outer surfaces of the bearing outer ring, which adversely affects the bearing function. Furthermore, the rolling behavior of the rolling elements on the track of the bearing outer ring is undefined and the oil supply to the storage can be disturbed. This can also have a negative effect, especially in the long-term operation of the storage unit.

Also in the axial direction undefined positions of the individual components of the bearing unit to each other, in particular the bearing outer rings to each other, due to their axial mobility in the axial direction can adversely affect the life of the bearing unit and there may be undesirable running noise and vibration in the bearing unit.

In order to avoid the disadvantages mentioned, it has already been proposed to elastically support the bearing outer rings of a corresponding bearing unit by means of a compression spring against each other and also to lock by means of a rotation in the housing of an exhaust gas turbocharger. According to the publication DE 10 2010 054 996 A1 For this purpose, it is proposed to mount the bearing unit within a carrier ring, which can then be inserted into a corresponding bore of a turbocharger housing. The bearing outer rings within the carrier ring are elastically supported against each other via a compression spring which bears inside the carrier ring and secured against rotation by means of pins, pins or bolts within the carrier ring. To prevent rotation come here also pins or bolts into consideration, which are inserted radially into the housing and thus secure the support ring against rotation. Thus, the outer race of both Wälzkörperreihen, which are provided at the axial ends of the bearing unit within the carrier ring, rotatably and axially secured relative to the support ring.

The carrier ring is mounted in the housing via a vibration-damping oil film and encloses the bearing outer rings completely and directly. Thus, the oil damping acts on the bearing ring on the bearing ring.

In embodiment of the carrier ring with a firmly connected socket a transport-secured bearing cartridge is achieved. Alternatively, for this purpose, the bearing inner ring be made in one piece and even serve as a transport lock.

Particularly disadvantageous in the aforementioned embodiment is the large number of different individual parts that have to be manufactured separately from one another and assembled during assembly. This makes the manufacture and assembly of the storage unit expensive. In particular, the nesting of radially inward compression spring, this partially encompassing outer bearing rings and this in turn umgreifendem carrier ring increase the necessary space and complexity in the assembly.

A disadvantage of the aforementioned embodiment is further that on the one hand, the production of the bearing outer rings receiving carrier ring, in particular in the form of an over the entire axial length of the bearing unit reaching bushing, consuming and expensive. Since the bearing outer rings must be used in the radial direction exactly in the carrier rings in order to achieve the necessary centering, the inside of the carrier ring and the outside of the bearing outer rings must be accurately machined. Also, the axial stop for the outer rings must be made exactly because it limits the axial play of the rotor in the housing. Further, the oil film damping takes place between the carrier ring and the housing, which complicates the installation of the bearing unit in the housing. In addition, the maximum possible bearing diameter is reduced by the support ring, which is why at constant Bore diameter in the housing only less viable bearings can be used.

EP 2 520 809 A2 discloses another bearing assembly for a turbocharger in which a spacer is positioned between the two bearing outer rings having an oil bore for conveying oil to the axial end faces of the spacer. As a result, a vibration-damping oil ring can be generated on the front side between the bearing outer rings and the spacer. Optionally, in turn, an axial compression spring, which supports the two bearing outer rings elastically against each other in the axial direction, in turn provided. The rolling bearings themselves are supplied with oil via radial bores in the bearing outer rings.

The spacer can be locked in the housing of the turbocharger, so that the oil supply is guaranteed. Since the bearing outer rings must rotate relative to the spacer to ensure the axial oil damping, however, occur in the oil supply to the bearings undefined states.

The present invention has for its object to provide a bearing unit for an exhaust gas turbocharger or a Abgasnutzturbine and a corresponding storage, which is improved over the prior art in that on the one hand vibrations and noises are reduced by axial displacements of the bearing outer rings and the bearing tolerances exactly adjustable are, preferably from the bearing manufacturer, such that the bearing unit can be used as a preassembled unit in the housing of an exhaust gas turbocharger or an exhaust gas turbine, but the production costs are reduced and the assembly is facilitated.

The object according to the invention is achieved by a bearing unit having the features of claim 1, by a bearing unit having the features of claim 3 and by a bearing unit having the features of claim 12. In the dependent claims particularly advantageous embodiments and a storage with a corresponding storage unit are specified.

A bearing unit according to the invention for an exhaust gas turbocharger or an exhaust gas turbine has at least one bearing inner ring. Advantageously, two separate bearing inner rings are provided which are supported in particular in the axial direction directly or via a spacer to each other. The two separate bearing rings can thus have the shape of a two-part hollow shaft. The at least one bearing inner ring can in particular be pressed or shrunk onto a turbine shaft with its inner surface, correspondingly with a torsion-proof interference fit.

Further, at least two bearing outer rings are provided and at least two rows of rolling elements, for example in the form of ball bearing rows, comprising a first row of rolling elements in the region of a first axial end of the bearing unit between a first of the two bearing outer rings and the at least one bearing inner ring and a second row of rolling elements in the region of the first axial End opposite the second axial end of the bearing unit between a second of the two bearing outer rings and the at least one bearing inner ring. If two bearing inner rings are provided, in particular one respective rolling element row is provided between a bearing inner ring and a bearing outer ring at the first axial end and between a bearing inner ring and a bearing outer ring at the second axial end.

According to one embodiment, the bearing unit according to the invention has an intermediate piece which is positioned at least partially in the axial direction between the two bearing outer rings. At least in part means that the intermediate piece according to one embodiment, the bearing outer rings can completely enclose on the outer periphery, but is positioned according to a further embodiment in the axial direction completely between the two outer bearing rings or particularly low, overlaps only a portion of each outer bearing ring in the axial direction, radially inside or radially outside.

According to the invention, each of the two bearing outer rings is then elastically supported with at least one spring element in relation to the intermediate piece in the axial direction. Thus, a central spring element, with which the two bearing outer rings are supported directly against each other, omitted, which facilitates the manufacture and assembly of the storage unit and optimizes the necessary space.

Particularly low in each case at least one rotation between the intermediate piece and each of the two bearing outer rings is provided so that the bearing outer rings can not rotate freely to avoid the aforementioned turning. In order to further reduce the number of parts further, the at least one spring element, with which a bearing outer ring is elastically supported relative to the intermediate piece in the axial direction, at the same time form the rotation between the intermediate piece and the respective bearing outer ring.

The storage unit according to the invention according to a further embodiment has at least two rows of rolling elements, namely at least one first row of rolling elements in the region of a first axial end of the bearing unit and at least one second row of rolling elements in the region of a second axial end of the bearing unit. The second axial end is opposite to the first axial end.

Furthermore, at least one first bearing outer ring is provided, which encloses the first row of rolling elements, and at least one second bearing outer ring, which encloses the second row of rolling elements.

Further, an intermediate piece is provided, which is positioned in the axial direction at least partially between the first and the second bearing outer ring. This includes both an embodiment in which the intermediate piece is positioned completely between the first and the second bearing outer ring, as well as such an embodiment in which the intermediate piece partially overlaps with the first and / or the second outer bearing ring in the axial direction.

According to the invention, a stationary component is provided which encloses the intermediate piece and the bearing outer rings. Such a stationary component, for example, be the housing of the exhaust gas turbocharger or the exhaust gas turbine, so that the intermediate piece and the bearing outer rings are enclosed radially outside directly from the housing. However, the stationary component can also be a separate, for example, fixed in a housing of the exhaust gas turbocharger or the exhaust gas turbine turbine component, from which the intermediate piece and the bearing outer rings are then immediately enclosed on its radial outer side. Stationary therefore means that the component does not rotate.

According to the intermediate piece is fixed in the stationary component, whereas the bearing outer rings are mounted in each case via an oil ring at least in the radial direction movable in the stationary component. The fixation of the intermediate piece in the stationary component has the effect that the intermediate piece can not move relative to the stationary component, in particular neither in the axial direction, nor in the radial direction or in the circumferential direction. By the provided oil ring radially outward between the bearing outer rings and the stationary component, however, an at least low mobility between the bearing outer rings and the stationary component is achieved in the radial direction, the oil rings are designed in particular as Quetschölfilm or Quetschöldämpfer to dampen the bearings.

Due to the direct mounting of the intermediate piece and the at least two outer bearing rings in a common stationary component, wherein the intermediate piece does not extend completely beyond the bearing outer rings in the axial direction, so that the oil ring damping can be provided directly between the outer bearing rings and the stationary component, in combination with Fixation of the intermediate piece in the stationary component, a bearing unit is provided which is axially fixed in the middle and in which set all axial play in this operation, starting from this axial center, which is advantageous in terms of minimal game addition. At the same time avoided by avoiding the initially described the bearing outer rings enclosing carrier ring, which in turn is mounted with an oil ring in the housing, the illustrated problem of the exact adjustment of the bearing outer rings to the contour of the carrier ring. Rather, the arrangement of the oil rings between the outer surface of the bearing outer rings and the inner surface of the stationary component, in particular of the housing, tolerances in the production of these surfaces.

According to this embodiment of the invention, at least one anti-rotation between the intermediate piece and each of the two bearing outer rings is provided so that the two bearing outer rings can not rotate in an undefined position.

It is also favorable in this embodiment, when the bearing outer rings by means of at least one spring element in the axial direction elastically against the intermediate piece or elastically supported against each other to avoid in the axial direction undefined positions of the bearing outer rings.

Advantageously, the respective spring element between a bearing outer ring and the intermediate piece at the same time forms the anti-rotation.

Particularly advantageous in all of the aforementioned embodiments of the invention, the spring element as a spiral spring or as a corrugated spring with at least one radially inwardly or radially outwardly directed projection. Such a corrugated spring advantageously has discretely arranged discretely distributed over the circumference bearing surfaces, of which a first number or plurality rests on the intermediate piece and a second number or plurality of the respective bearing outer ring. The radially inwardly or radially outwardly directed projection can penetrate the intermediate piece in the radial direction and at least intervene in the respective outer bearing ring in the radial direction or even pass through it. Alternatively, the radially inwardly or radially outwardly directed projection penetrate the respective bearing outer ring in the radial direction and at least intervene in the intermediate piece in the radial direction or reach through this, so as to produce the rotation.

In one embodiment, with a corrugated spring, this may be executed interrupted over its circumference, with two circumferential ends which overlap one another or which are arranged at a distance from one another. In the latter case, the corrugated spring thus does not extend over 360 ° of the circumference, but only over a smaller angular range.

According to an advantageous embodiment of the invention, each of the two bearing outer rings in the axial direction inwardly projecting collar with respect to the axially outwardly adjoining region of the bearing outer rings reduced outer diameter, and the intermediate piece encloses in the axial direction only the respective collar of the bearing outer rings in the circumferential direction, wherein advantageous the respective at least one rotation in the respective collar and the intermediate piece is provided.

In one embodiment of the invention, the intermediate piece or each subsequent in the axial direction bearing outer ring on an open-edged circumferential groove, in which the spring element is positioned. The spring element can thus be supported in the axial direction on one side against an edge-open groove limiting end face of the intermediate piece or the bearing outer ring and on the other side corresponding to an end face of the other component, in training the open-edged circumferential groove in the intermediate piece of the bearing outer ring or training the open-edged circumferential groove in the bearing outer ring of the intermediate piece.

Particularly advantageously, the spring element is positioned radially within the outer diameter of the intermediate piece in the circumferential groove.

According to one embodiment of the invention, the bearing unit has at least one spring element, which is provided in the axial direction between the two bearing outer rings and the two bearing outer rings axially under elastic pressurization supported against each other. The support can be direct or indirect. In a direct support only the at least one spring element between the two bearing outer rings is positioned to the mutual support. In an indirect support further components between the two bearing outer rings and the at least one spring element in the power flow of the mutual support are arranged, for example, as previously described with reference to the possible inventive design. Thus, the two rows of rolling elements advantageously receive a preload in the axial direction via the bearing outer rings and, in particular, are supported against a radially outwardly projecting shoulder of the bearing inner rings due to the pretension in each operating state. Thus, the bearing outer rings and the bearing inner rings are in each operating condition of the bearing unit on the rolling elements in the axial direction and in particular in the radial direction to each other and indefinite storage conditions are avoided.

In the aforementioned design according to the invention, an intermediate piece is provided in the axial direction between the two bearing outer rings and in each case an anti-rotation between the intermediate piece and each of the two bearing outer rings. In this way, in particular when the intermediate piece is held against rotation in a housing of the exhaust gas turbocharger or the exhaust gas turbine, is held for example via a press fit in a corresponding bore of the housing, a rotation of the two bearing outer rings relative to each other and relative to the housing avoided. This also contributes to a defined rolling behavior in the bearing and to reduced vibrations and reduced wear.

According to this embodiment of the invention, each of the two bearing outer rings now has an axially inwardly projecting collar, which has a reduced outer diameter in relation to the region of the bearing outer rings which adjoins each other axially outwards. The two collars of the two bearing outer rings are therefore directed towards each other and positioned between the regions of the two bearing outer rings with a comparatively larger, in particular constant, outer diameter.

According to this embodiment, the intermediate piece surrounds the two outer bearing rings in the circumferential direction only over the axial section of the respective collar, therefore not in the region of the comparatively larger outer diameter at the respective axial end of the bearing unit. Thus, the intermediate piece overlaps the respective collar of the bearing outer ring, but advantageously not the region of the rolling element rows.

In general, the two collars are arranged in the axial direction at a distance from each other, wherein this distance from the intermediate piece, which is in particular made in one piece, is bridged. In the distance, the spring element may be provided, which is advantageously designed as a corrugated spring, which rests with individual discrete distributed over the circumference arranged contact surfaces frontally on the bearing outer rings and thus axially against the bearing outer rings to push them apart in the axial direction of the bearing unit.

It is particularly favorable if one or both of the at least two anti-rotation devices as snap ring interrupted over the circumference with at least one intermediate piece in the radial direction penetrating projection is / are performed, wherein the projection engages in the respective bearing outer ring in the radial direction or penetrates. With such a snap ring, also called snap ring, a particularly simple rotation and disassembly safe bearing unit can be created, in which the games to be adjusted between the individual components are achieved in a preassembled state, so that the bearing unit as a preassembled module in a corresponding exhaust gas turbocharger or exhaust gas turbine for mounting the turbine shaft can be installed in a housing. The fact that the pre-assembly can be done at the bearing manufacturer, and thus not the supplied exhaust gas turbocharger manufacturer or turbine manufacturer must perform the alignment of the individual bearing components relative to each other, an optimal assembly can be achieved in the assembly errors can be largely avoided and simultaneously low bearing clearance and bearing clearance tolerances feasible are. This leads to a longer life and better performance of the storage unit and thus the entire exhaust gas turbocharger or the exhaust gas turbine.

The intermediate piece advantageously has at least one, in particular two circumferential grooves, so that a snap ring can be mounted as a rotation lock in a circumferential groove. In this case, the snap ring can be positioned radially within the outer diameter of the intermediate piece in the circumferential groove, that is he does not stand on the outer diameter of the intermediate piece, which facilitates the assembly of the intermediate piece in the housing and at the same time a further assurance of the snap ring, which is particularly elastic, causes. Except for the at least one, advantageously two circumferential grooves, the intermediate piece may have an at least substantially constant outer diameter.

It is advantageous if the intermediate piece has two axially outer end faces, each facing an axially inwardly directed shoulder of the bearing outer rings with an axial clearance. In this case, the intermediate piece extends only from one outer end side to the other outer end side, to which then connect the two bearing outer rings in the axial direction.

The anti-rotation can be advantageously prepared as a cost-effective stamped part and simply clipped onto the intermediate piece and in the two bearing outer rings.

It is favorable if the intermediate piece extends in the axial direction only between the rows of rolling elements, therefore does not extend beyond the rows of rolling elements. According to a preferred embodiment, the intermediate piece on two axially outer end faces, each facing an axially inwardly directed shoulder of the bearing outer rings with an axial play. These end faces may, for example, be positioned at the axially outer end of the circumferential groove when forming an edge-open circumferential groove in the intermediate piece.

The outer diameter of the intermediate piece advantageously corresponds substantially to the outer diameter of the bearing outer rings. According to one embodiment, however, the outer diameter of the intermediate piece is slightly larger than the outer diameter of the bearing outer rings, so that the intermediate piece can be mounted in a press fit in the housing, whereas between the bearing outer rings and the housing remains a game, in particular for forming an oil film or oil gap, in particular for the production of a Quetschöldämpers.

In particular, the maximum outer diameter of the intermediate piece is less than 10%, advantageously less than 5%, in particular less than 1% greater than the maximum outer diameter of the two bearing outer rings.

The two bearing outer rings have according to an embodiment identical outer diameter and in particular identical inner diameter.

The intermediate piece is advantageously positioned with a radial play on the projecting collars of the bearing outer rings.

The intermediate piece can be made of a different, in particular more favorable material than the bearing outer rings.

The anti-rotation devices advantageously have a play in the axial direction and / or circumferential direction in relation to the intermediate piece and / or the bearing outer rings.

The rolling elements in the rows of rolling elements are held in cages according to an embodiment of the invention. The cages can be guided on the outside, that is, in radial contact with the bearing outer ring. Other designs are possible.

Depending on the installation conditions, it is favorable if oil bores are provided in the bearing outer rings for lubricating oil supply of the rolling element rows, but not in the intermediate piece. Advantageously, the oil holes are arranged in the axial direction between the raceways of Wälzkörperreihen and the intermediate piece.

In a further embodiment, the oil supply can take place via the bores, which are penetrated by the spring element projections. They are in particular radially in the intermediate piece and the collar of the bearing outer rings and are aligned in alignment with each other after assembly of the spring elements on the respective spring element projection, so that the oil can be directed into the bearing interior.

The two rows of rolling elements, together with the bearing outer rings and the at least one bearing inner ring, in particular the two bearing inner rings form a rolling bearing with a so-called O-arrangement. In such an O-arrangement in a bearing, the employment is such that the power flow lines through the bearings have a center of pressure axially outside the rows of rolling elements, at least outside the axial center thereof.

Due to the design according to the invention, the bearing outer rings can be comparatively solid with a large outer diameter, so that the bearing capacity of the bearing unit is improved. In addition, the radial mobility is reduced, which has a favorable effect on the life.

In an inventive storage of an exhaust gas turbocharger or an exhaust gas turbine, the two bearing outer rings and the intermediate piece can be enclosed directly by the housing, that is without the interposition of other components. According to one embodiment, only an oil film or oil ring is provided between the bearing outer rings and the housing to achieve oil damping. The intermediate piece is advantageously introduced in an adjacent fit or even press fit into the housing.

To the bearing according to the invention of the turbocharger a turbine wheel or a compressor wheel and an electric generator can also be mounted by means of the turbine shaft.

Advantageously, an axial locking between the bearing unit and the housing only in the region of the intermediate piece, in particular by the said pressing of the intermediate piece in the housing produced.

In particular, if a clearance remains between the bearing outer rings and the housing, a costly accurate reworking of the outer surface of the bearing outer rings and the bearing housing bore can be omitted at least in the area of the bearing outer rings. According to one embodiment of the invention, only the radially outer surface of the intermediate piece must be ground or finely turned after production, and in particular the end faces facing the bearing outer rings.

In the aforementioned embodiment, according to which each of the two bearing outer rings has an axially inwardly projecting collar, the two collars of the two bearing outer rings are directed towards each other and positioned between the areas of the two bearing outer rings with comparatively larger, in particular constant, outer diameter. In this embodiment, the intermediate piece does not surround the two outer bearing rings in the region of the comparatively larger outer diameter at the respective axial end of the bearing unit and overlaps the respective collar of the outer bearing ring, but advantageously not the region of the rolling element rows.

The two collars can be arranged in the axial direction at a distance from each other, wherein the distance can be a multiple of the axial length of the collar. However, this is not mandatory.

The internally protruding frets of comparatively reduced diameter on the bearing outer rings can have a constant diameter.

According to one embodiment of the invention, the intermediate piece has a constant inner diameter.

The axially outwardly projecting collars of the bearing outer rings can be made closed over the circumference. However, according to an alternative embodiment, they are interrupted over the circumference.

Particularly in the design with the spring element as a spiral spring or as a corrugated spring with at least one radially inwardly or radially outwardly directed projection, a particularly simple rotation and disassembly safe bearing unit can be created, in which the games to be set between the individual components achieved in a preassembled state be so that the bearing unit can be installed as a preassembled module in a corresponding exhaust gas turbocharger or a Abgasnutzturbine for supporting the turbine shaft in a housing. The fact that the pre-assembly can be done at the bearing manufacturer and thus not the supplied exhaust gas turbocharger manufacturer or turbine manufacturer must perform the alignment of the individual position components relative to each other, optimal assembly can be achieved in the assembly errors can be largely avoided while low bearing clearance and bearing clearance tolerances are feasible , This leads to a prolonged life and better performance of the storage unit and thus the entire exhaust gas turbocharger or the exhaust gas turbine.

The embodiment of the spring element as a corrugated spring causes an improved damping of vibrations. It is negligible in a compression compared to a cylindrical compression spring less linear spring constant due to the small stroke occurring during operation.

If the intermediate piece is locked axially in the housing of the exhaust gas turbocharger or the exhaust gas utilization turbine and the two outer bearing rings are movable in the axial direction at least limited relative to the housing, an optimized temperature behavior during operation can be achieved.

An exhaust gas turbocharger according to the invention or an exhaust gas turbine according to an advantageous embodiment of the invention has a housing and a turbine shaft mounted in the housing. The turbine shaft is mounted in the housing by means of a bearing unit according to the invention. In this case, the stationary component of the bearing unit may be fixed in the housing, advantageously in the axial direction, radial direction and in the circumferential direction. Particularly preferably, however, the stationary component is formed by the housing itself, so that the intermediate piece is fixed directly in the housing and the two bearing outer rings facing the housing only with the interposition of the respective oil ring.

The bearing outer rings form outer Wälzkörperlaufbahnen for the rows of rolling elements. Internal rolling element raceways for the rows of rolling elements can be formed either by the turbine shaft itself, which is also referred to as the integral shaft, or by separate bearing inner rings, which receive the turbine shaft.

The intermediate piece is advantageously pressed in this embodiment in the housing of the exhaust gas turbocharger or the exhaust gas turbine.

Again, the intermediate piece can be made of another, in particular cheaper material than the bearing outer rings.

A turbine wheel and a compressor wheel and / or an electric generator can be mounted on the turbine shaft. When designing a turbocompound system, a turbine wheel may also be mounted in combination with a pinion on the turbine shaft.

According to one embodiment of the invention, only the radially outer surface of the intermediate piece must be ground or finely turned after production, and in particular the end faces of the intermediate piece facing the bearing outer rings. A post-processing of the outer surface of the bearing outer rings and in particular the bearing housing bore, at least in the region of the bearing outer rings can be omitted.

The invention will be described below by way of example with reference to an embodiment and the figures.

Show it:

1 a three-dimensional exploded view of a storage unit according to the invention;

2 a frontal plan view of a storage unit according to the invention;

3 an axial section corresponding to the section line AA in the 2 ;

3a a detailed view of one opposite the 3 changed anti-twist device;

4 a three-dimensional exploded view of another storage unit according to the invention;

5 a frontal plan view of the further storage unit according to the invention;

6 an axial section corresponding to the section line AA in the 5 ,

In the 1 a storage unit according to the invention is shown, with two bearing inner rings 1 . 2 and two bearing outer rings 3 . 4 , with corresponding rows of rolling elements 5 . 6 two rolling bearings, here ball bearings, train.

The rolling elements of the rows of rolling elements 5 . 6 be in the embodiment shown in cages 21 between the bearing inner rings 1 . 2 and the bearing outer rings 3 . 4 are positioned.

The bearing outer rings 3 . 4 have an axially projecting collar 10 with reduced outside diameter. When assembled, the frets grip 10 the bearing outer rings 3 . 4 , where the frets 10 in particular in one piece with the respective bearing outer ring 3 . 4 are executed, in an axial direction between the two bearing outer rings 3 . 4 positioned intermediate piece 8th one. The intermediate piece 8th encloses or overlaps only those axial portion of the two bearing outer rings 3 . 4 who by the respective covenant 10 is formed, but not the subsequent areas in which the rows of rolling elements 5 . 6 are and a comparatively larger diameter exhibit. Rather, the areas with comparatively larger diameter of the two bearing outer rings 3 . 4 and the intermediate piece 8th essentially the same, in particular in each case cylindrical outer diameter.

The bearing outer rings 3 . 4 and the intermediate piece 8th have at the mutually facing axial ends a bore, which in the illustrated embodiment, on the one hand as an oil hole 16 serves, via which the rolling bearings are supplied with lubricating oil. These oil wells 16 are axially between the raceways of Wälzkörperreihen 5 . 6 arranged.

At the same time these holes serve to accommodate anti-rotation 9 , as a spring element interrupted over the circumference 7 are executed, wherein each spring element 7 is designed here as a corrugated spring, which on the one hand on a shoulder 15 each of a bearing outer ring 3 . 4 and on the other hand on a shoulder 26 of the intermediate piece 8th supported, see also the 3 , The shoulder 26 limits an open-edged circumferential groove 13 at each axial end of the intermediate piece 8th , wherein each circumferential groove 13 to the front side 14 of the intermediate piece 8th enough and this front page 14 with more or less axial play 22 the shoulder 15 of the respective bearing outer ring 3 . 4 faces. Depending on the operating state, the axial play 22 also be completely bypassed.

Due to the design shown, the two bearing outer rings 3 . 4 in the axial direction elastically over the spring elements 7 and the intermediate piece 8th supported against each other.

The assembly of the spring elements 7 is simple, they can be spread elastically easily in the circumferential grooves 13 are introduced from radially outside, so that they in the circumferential grooves 13 and here the oil wells 16 snap. The spring elements 7 can therefore also as snap rings 11 be designated.

Because at the same time radial projections 12 the spring elements 7 the intermediate piece 8th penetrate in the radial direction and in each case one of the two bearing outer rings 3 . 4 engage or attack the wall thickness, a rotation of the bearing outer rings 3 . 4 opposite the intermediate piece 8th prevented. That is in the 3 , of the 3a as well as in the 6 to see.

Because of the holes in the intermediate piece 8th or in the bearing outer rings 3 . 4 are made larger in the axial direction than the radial projections 12 , remains a sufficient free cross section, so that the holes, as stated, as an oil well 16 can be used. In particular, if the projections 12 have a geometrically different cross-section than the holes, for example, designed as a flat wire, a remaining free cross-section is certainly achieved in the most circular holes.

The radial projections 12 do not have to be at a circumferential end of the spring elements 7 be provided, but could also be provided at a different position, for example in the region of the center of the circumference.

The design of the storage unit from the 1 is also in the 2 and 3 shown in a frontal plan view and an axial section. Corresponding components are identified by corresponding reference numerals. Especially from the 2 It can be seen that the bearing outer rings, visible here on the bearing outer ring 3 , can be made with a relatively large thickness in the radial direction, which contributes to the rigidity of the bearing.

From the 3 it can be seen that the two bearing inner rings 1 . 2 abut each other at the front. The bearing rings 1 . 2 can thus in the form of a two-part hollow shaft 24 . 25 be educated. The hollow shaft 24 . 25 , consisting of the bearing inner rings 1 . 2 can, for example, a turbine shaft schematically indicated only by dashed lines here 17 shrunk down. However, this is not mandatory. Such a turbine shaft 17 can be connected to a Abgasturbinenrad and a compressor wheel, or with an exhaust turbine and a pinion, the latter in the case of use in a turbocompound system. Also it is possible the turbine shaft 17 to connect with an electric generator or its rotor. Preferably, the bearing inner rings 1 . 2 integral in the respective hollow shaft 24 . 25 integrated.

The intermediate piece 8th can in a housing 18 an exhaust gas turbocharger or an exhaust gas turbine to be pressed, whereas the bearing outer rings 3 . 4 advantageously a radial play against an inner surface of the housing 18 have, so for example, an oil film or oil ring 20 between the case 18 and the bearing outer rings 3 . 4 can be provided for vibration damping.

The bearing unit is in particular in a bore 19 of the housing 18 assembled.

In the embodiment shown, the intermediate piece 8th Furthermore, a bore for forming an oil drain 23 on.

Although in the illustrated embodiment, the spring element 7 in a circumferential groove 13 at each axial end of the intermediate piece 8th is arranged, could be a corresponding spring element 7 also in a corresponding circumferential groove 13 of the respective bearing outer ring 3 . 4 be positioned and with his lead 12 first the bearing outer ring 3 . 4 succeed. This is schematically in the detail a of 3 shown. It is also possible in principle that the spring element 7 in a radially inwardly directed circumferential groove 13 is provided and a corresponding radially outwardly directed projection 12 having, which the respective bearing outer ring 3 . 4 and the intermediate piece 8th penetrates or at least partially penetrates into this / these.

In the 4 a further bearing unit according to the invention is shown, with two bearing inner rings 1 . 2 and two bearing outer rings 3 . 4 , with corresponding rows of rolling elements 5 . 6 two rolling bearings, here ball bearings, train.

The rolling elements of the rows of rolling elements 5 . 6 be in the embodiment shown in cages 21 between the bearing inner rings 1 . 2 and the bearing outer rings 3 . 4 are positioned.

The bearing outer rings 3 . 4 are in the axial direction via a spring element 7 , here in the form of a wave spring, elastically supported against each other. The bearing outer rings each have at least one, in particular exactly one, oil bore 16 on, over which the rolling bearings are supplied with lubricating oil. This oil hole 16 is axially between the raceways of Wälzkörperreihen 5 . 6 and the intermediate piece 8th arranged.

The bearing outer rings 3 . 4 have an axially projecting collar 10 with reduced outside diameter. When assembled, the frets grip 10 the bearing outer rings 3 . 4 , where the frets 10 in particular in one piece with the respective bearing outer ring 3 . 4 are executed, in an axial direction between the two bearing outer rings 3 . 4 positioned intermediate piece 8th one. The intermediate piece 8th encloses or overlaps only those axial portion of the two bearing outer rings 3 . 4 who by the respective covenant 10 is formed, but not the subsequent areas in which the rows of rolling elements 5 . 6 are located and have a comparatively larger diameter. Rather, the areas with comparatively larger diameter of the two bearing outer rings 3 . 4 and the intermediate piece 8th essentially the same, in particular in each case cylindrical outer diameter.

In the intermediate piece 8th are two circumferential grooves 13 introduced, more precisely on the outer circumference. Each of the circumferential grooves 13 takes a rotation lock 9 on, with which the two bearing outer rings 3 . 4 against rotation on the intermediate piece 8th to be assembled.

The two anti-rotation devices 9 are here as over the circumference broken snap ring 11 executed. Every snap ring 11 has at least one, here exactly one, projection 12 on, the intermediate piece 8th penetrates in the radial direction and in each case one of the two bearing outer rings 3 . 4 engages or its wall thickness passes through.

The design of the storage unit from the 4 is also in the 5 and 6 shown in a frontal plan view and an axial section. Corresponding components are identified by corresponding reference numerals. Especially from the 5 It can be seen that the bearing outer rings, visible here on the bearing outer ring 3 , can be made with a relatively large thickness in the radial direction, which contributes to the rigidity of the bearing.

From the 6 it can be seen that the two bearing inner rings 1 . 2 abut each other at the front. The bearing rings 1 . 2 can thus in the form of a two-part hollow shaft 24 . 25 be educated. The hollow shaft 24 . 25 , consisting of the bearing inner rings 1 . 2 can, for example, a turbine shaft schematically indicated only by dashed lines here 17 shrunk down. However, this is not mandatory. Such a turbine shaft 17 can be connected to a Abgasturbinenrad and a compressor wheel, or with an exhaust turbine and a pinion, the latter in the case of use in a turbocompound system. Also it is possible the turbine shaft 17 to connect with an electric generator or its rotor. Preferably, the bearing inner rings 1 . 2 integral in the respective hollow shaft 24 . 25 integrated.

The intermediate piece 8th can in a housing 18 an exhaust gas turbocharger or an exhaust gas turbine to be pressed, whereas the bearing outer rings 3 . 4 advantageously a radial play against an inner surface of the housing 18 have, so for example, an oil film or oil ring 20 between the case 18 and the bearing outer rings 3 . 4 can be provided for vibration damping.

The bearing unit is in particular in a bore 19 of the housing 18 assembled.

From the 6 is also apparent that the intermediate piece 8th two end faces 14 each having an axially inwardly directed shoulder 15 with a more or less big axial play 22 faces. Depending on the operating state, the axial play 22 also be completely bypassed.

In the embodiment shown, the intermediate piece 8th Furthermore, a bore for forming an oil drain 23 on.

LIST OF REFERENCE NUMBERS

1

 Bearing inner ring

2

 Bearing inner ring

3

 Bearing outer ring

4

 Bearing outer ring

5

 rows of rolling elements

6

 rows of rolling elements

7

 spring element

8th

 connecting piece

9

 twist

10

 frets

11

 snap ring

12

 head Start

13

 circumferential grooves

14

 front sides

15

 shoulder

16

 oil well

17

 turbine shaft

18

 casing

19

 drilling

20

 oil ring

21

 cages

22

 end play

23

 oil drain

24

 hollow shaft

25

 hollow shaft

26

 shoulder

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010054996 A1 [0005]
• EP 2520809 A2 [0010]

Claims (31)

Bearing unit for an exhaust gas turbocharger or an exhaust gas turbine 1.1 with at least one bearing inner ring ( 1 . 2 ); 1.2 with at least two bearing outer rings ( 3 . 4 ); 1.3 with at least two rows of rolling elements ( 5 . 6 ), comprising a first row of rolling elements ( 5 ) in the region of a first axial end of the bearing unit between a first of the two bearing outer rings ( 3 ) and the at least one bearing inner ring ( 1 . 2 ) and a second row of rolling elements ( 6 ) in the region of a second axial end of the bearing unit opposite the first axial end, between a second of the two bearing outer rings ( 4 ) and the at least one bearing inner ring ( 1 . 2 ); 1.4 with an intermediate piece ( 8th ), which at least partially in the axial direction between the two bearing outer rings ( 3 . 4 ) is positioned; characterized in that 1.5 each bearing outer ring ( 3 . 4 ) each having at least one spring element ( 7 ) elastically with respect to the intermediate piece ( 8th ) is supported in the axial direction. Bearing unit according to claim 1, characterized in that in each case at least one anti-rotation ( 9 ) between the intermediate piece ( 8th ) and each of the two bearing outer rings ( 3 . 4 ) is provided. Bearing unit for an exhaust gas turbocharger or an exhaust gas turbine 3.1 with at least two rows of rolling elements ( 5 . 6 ), comprising a first row of rolling elements ( 5 ) in the region of a first axial end of the bearing unit and a second row of rolling elements ( 6 ) in the region of a second axial end of the bearing unit opposite the first axial end; 3.2 with at least one first bearing outer ring ( 3 ), the first row of rolling elements ( 5 ), and at least one second bearing outer ring ( 4 ), the second row of rolling elements ( 6 ) encloses; 3.3 with an intermediate piece ( 8th ), which in the axial direction at least partially between the first and the second bearing outer ring ( 3 . 4 ) is positioned; 3.4 with one the intermediate piece ( 8th ) and the bearing outer rings ( 3 . 4 ) enclosing stationary component; where 3.5 is the intermediate piece ( 8th ) is fixed in the stationary component, whereas the bearing outer rings ( 3 . 4 ) each via an oil ring ( 20 ) are mounted movably in the stationary component at least in the radial direction; characterized in that each 3.6 at least one rotation ( 9 ) between the intermediate piece ( 8th ) and each of the two bearing outer rings ( 3 . 4 ) is provided. Bearing unit according to claim 3, characterized in that the stationary component is a housing ( 18 ) is for the exhaust gas turbocharger or the exhaust gas turbine. Bearing unit according to one of claims 3 or 4, characterized in that the bearing outer rings ( 3 . 4 ) by means of at least one spring element ( 7 ) in the axial direction elastically with respect to the intermediate piece ( 8th ) or are supported against each other. Bearing unit according to claim 1 and claim 2 or according to claim 5, characterized in that the respective at least one spring element ( 7 ) at the same time the rotation ( 9 ) between the intermediate piece ( 8th ) and the respective bearing outer ring ( 3 . 4 ) trains. Bearing unit according to claim 6, characterized in that the spring element ( 7 ) as a spiral spring or as a wave spring with at least one radially inwardly or radially outwardly directed projection ( 12 ) is executed, which the intermediate piece ( 8th ) penetrates in the radial direction and into the respective bearing outer ring ( 3 . 4 ) at least engages in the radial direction or which the respective bearing outer ring ( 3 . 4 ) penetrates in the radial direction and into the intermediate piece ( 8th ) at least engages in the radial direction. Bearing unit according to claim 7, characterized in that the corrugated spring is interrupted over its circumference, with two circumferential ends which overlap one another or which are arranged at a distance from one another. Bearing unit according to one of claims 1 to 8, characterized in that each of the two bearing outer rings ( 3 . 4 ) an axially inwardly projecting collar ( 10 ) with respect to the axially outwardly adjoining region of the bearing outer rings ( 3 . 4 ) has reduced outer diameter and the intermediate piece ( 8th ) in the axial direction only the respective bundle ( 10 ) of the bearing outer rings ( 3 . 4 ) encloses in the circumferential direction, wherein in each case at least one anti-rotation ( 9 ) between the respective federation ( 10 ) and the intermediate piece ( 8th ) is provided. Bearing unit according to one of claims 7 to 9, characterized in that the intermediate piece ( 8th ) or in each case in the axial direction subsequent bearing outer ring ( 3 . 4 ) an open-edged circumferential groove ( 13 ), in which the spring element ( 7 ) is positioned. Bearing unit according to claim 10, characterized in that the spring element ( 7 ) radially within the outer diameter of the intermediate piece ( 8th ) in the circumferential groove ( 13 ) is positioned. Bearing unit for an exhaust gas turbocharger or an exhaust gas turbine 12.1 with at least one bearing inner ring ( 1 . 2 ); 12.2 with at least two bearing outer rings ( 3 . 4 ); 12.3 with at least two rows of rolling elements ( 5 . 6 ), comprising a first row of rolling elements ( 5 ) in the region of a first axial end of the bearing unit between a first of the two bearing outer rings ( 3 ) and the at least one bearing inner ring ( 1 . 2 ) and a second row of rolling elements ( 6 ) in the region of a second axial end of the bearing unit opposite the first axial end, between a second of the two bearing outer rings ( 4 ) and the at least one bearing inner ring ( 1 . 2 ); 12.4 with at least one spring element ( 7 ) in the axial direction between the two bearing outer rings ( 3 . 4 ), which the two bearing outer rings ( 3 . 4 ) under pressure directly or indirectly axially supported against each other; 12.5 with an intermediate piece ( 8th ) in the axial direction between the two bearing outer rings ( 3 . 4 ); 12.6 with at least one anti-twist device ( 9 ) between the intermediate piece ( 8th ) and each of the two bearing outer rings ( 3 . 4 ); characterized in that 12.7 each of the two bearing outer rings ( 3 . 4 ) an axially inwardly projecting collar ( 10 ) with respect to the axially outwardly adjoining region of the bearing outer rings ( 3 . 4 ) has reduced outer diameter and the intermediate piece ( 8th ) in the axial direction only the respective bundle ( 10 ) of the bearing outer rings ( 3 . 4 ) encloses in the circumferential direction, wherein in each case at least one anti-rotation ( 9 ) between the respective federation ( 10 ) and the intermediate piece ( 8th ) is provided. Bearing unit according to claim 12, characterized in that one or both of the at least two anti-rotation devices ( 9 ) as a snap ring interrupted over the circumference ( 11 ) with at least one the intermediate piece ( 8th ) radially penetrating projection (FIG. 12 ) is / are executed, which in the respective bearing outer ring ( 3 . 4 ) engages in the radial direction or passes through this. Bearing unit according to claim 13, characterized in that the intermediate piece ( 8th ) at least one circumferential groove ( 13 ), in which the snap ring ( 11 ) is positioned. Bearing unit according to claim 14, characterized in that the snap ring ( 11 ) radially within the outer diameter of the intermediate piece ( 8th ) in the circumferential groove ( 13 ) is positioned. Bearing unit according to one of claims 12 to 15, characterized in that the spring element ( 7 ) is designed as a corrugated spring which is arranged with individual discrete distributed over the circumference arranged contact surfaces on the respective collar ( 10 ) of the bearing outer rings ( 3 . 4 ) abuts axially. Bearing unit according to one of claims 1 to 16, characterized in that the intermediate piece ( 8th ) in the axial direction only between the rows of rolling elements ( 5 . 6 ). Bearing unit according to one of claims 1 to 17, characterized in that the intermediate piece ( 8th ) two axially outer end faces ( 14 ) each having an axially inwardly directed shoulder ( 15 ) of the bearing outer rings ( 3 . 4 ) with an axial play ( 22 ). Bearing unit according to one of claims 1 to 18, characterized in that the outer diameter of the intermediate piece ( 8th ) substantially the outer diameter of the bearing outer rings ( 3 . 4 ) corresponds. Bearing unit according to one of claims 1 to 19, characterized in that the bearing outer rings ( 3 . 4 ) Oil wells ( 16 ) for lubricating oil supply of the rows of rolling elements ( 5 . 6 ) and the intermediate piece ( 8th ) is free of such oil wells. Bearing unit according to claim 20, characterized in that the oil bores ( 16 ) in the axial direction between raceways of Wälzkörperreihen ( 5 . 6 ) and the intermediate piece ( 8th ) are arranged. Bearing unit according to one of claims 1 to 21, characterized in that two axially adjacent bearing inner rings ( 1 . 2 ) are provided. Bearing unit according to one of claims 1 to 22, characterized in that the two rows of rolling elements ( 5 . 6 ) together with the bearing outer rings ( 3 . 4 ) and the at least one bearing inner ring ( 1 . 2 ) form a rolling bearing with O-arrangement. Storage of an exhaust gas turbocharger or an exhaust gas turbine 24.1 with a bearing unit according to one of claims 1 to 23; 24.2 with a in the at least one bearing inner ring ( 1 . 2 ) mounted turbine shaft ( 17 ); 24.3 with one of the two bearing outer rings ( 3 . 4 ) and the intermediate piece ( 8th ) enclosing housing ( 18 ). Bearing according to claim 24, characterized in that the bearing inner rings ( 1 . 2 ) in the form of a two-part hollow shaft ( 24 . 25 ) are formed and the hollow shaft ( 24 . 25 ) the turbine shaft ( 17 ). Bearing according to claim 24 or 25, characterized in that the two bearing outer rings ( 3 . 4 ) free of a sleeve enclosing this in a bore ( 19 ) in the housing ( 18 ) are included. Bearing according to one of claims 24 to 26, characterized in that the intermediate piece ( 8th ) in the housing ( 18 ), especially in the bore ( 19 ) in the housing ( 18 ), is pressed. Bearing according to one of claims 24 to 27, characterized in that the bearing outer rings ( 3 . 4 ) via an oil film or oil ring ( 20 ) directly in the housing ( 18 ) are mounted. Bearing according to one of claims 24 to 28, characterized in that only in the region of the intermediate piece ( 8th ) an axial locking between the bearing unit and the housing ( 18 ) is made. Exhaust gas turbocharger with a bearing according to one of claims 24 to 29, characterized in that on the turbine shaft ( 17 ) An exhaust gas turbine and a compressor and / or the rotor of an electric generator are mounted. Exhaust gas turbocharger or exhaust gas turbine 31.1 with a housing ( 18 ); 31.2 with a turbine shaft ( 17 ); characterized in that 31.3 the turbine shaft ( 17 ) by means of a bearing unit according to one of claims 3 to 11 in the housing ( 18 ), wherein the stationary component in the housing ( 18 ) is fixed or is formed by this and the turbine shaft ( 17 ) in at least one provided in the bearing unit bearing inner ring ( 1 . 2 ), which together with the bearing outer rings ( 3 . 4 ) the rows of rolling elements ( 5 . 6 ) including rolling element raceways, or the turbine shaft (FIG. 17 ) with the bearing outer rings ( 3 . 4 ) the rows of rolling elements ( 5 . 6 ) incorporating rolling element raceways.

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