DE102014212620B4 - Radial rolling bearing of an exhaust gas turbocharger - Google Patents

Abstract

Radial rolling bearing (1) of an exhaust gas turbocharger comprising at least one ball (4) as rolling elements (4) leading Wälzkörperkäfig and at least one bearing outer ring (2), with at least one bearing outer ring (2) radially penetrating spray oil bore (12, 13) and at least one circumferential an annular bearing surface (15, 16) for guiding a rolling body cage (7, 8) of the radial roller bearing (1), characterized in that an inner surface (14) ) arranged outlet of the spray oil bore (12, 13) partially within an axial extent of the guide surface (15, 16) and against the guide surface (15, 16) by a predetermined amount axially in the direction of a on the inner lateral surface (14) of the bearing outer ring ( 2) arranged track (20, 21) for guiding rolling elements (4) is offset.

Description

Field of the invention

The invention relates to a radial roller bearing of an exhaust gas turbocharger, comprising at least one ball rolling element as Wälzkörperkäfig bearing and at least one bearing outer ring with at least one radially outer annular bearing oil bore and at least one circumferentially arranged on an inner circumferential surface of the bearing outer ring, ring-shaped guide surface for guiding a Wälzkörperkäfigs of Radialwälzlagers.

State of the art

An exhaust-gas turbocharger of an internal combustion engine has a turbine wheel, a compressor wheel and a rotor shaft connecting the turbine wheel in a rotationally fixed manner to the compressor wheel. The rotor shaft is usually arranged rotatably in a housing of the turbocharger via at least one radial rolling bearing or radial plain bearing.

A radial roller bearing for an exhaust gas turbocharger can be designed to accommodate radial and axial loads as a double-row shoulder ball bearings or angular contact ball bearings. A shoulder ball bearing has a usual for deep groove ball bearings training of the bearing inner ring, while the bearing outer ring is provided with a shoulder. In the angular ball bearing, on the other hand, both the bearing outer ring and the bearing inner ring are provided with shoulders. A fully assembled radial rolling bearing can be placed on a rotor shaft of an exhaust gas turbocharger. Subsequently, the assembly formed from the radial rolling bearing and the rotor shaft can be inserted into a housing of an exhaust gas turbocharger.

A bearing outer ring of the type described above is known from DE 10 2010 054 904 A1 known. This discloses a double-row radial rolling bearing for an exhaust gas turbocharger, einin with a bearing housing of the exhaust gas turbocharger carrier rings, one of the support rings radially encompassed bearing outer ring and a rotatable about Wälzkörperreihen arranged in the bearing outer ring bearing inner ring. Such a construction of the double-row radial rolling bearing is also referred to as a bearing cartridge. The rolling elements of each row of rolling elements are each arranged spaced from one another by means of a rolling element cage and are guided relative to one another by means of the respective rolling element cage. On an inner circumferential surface of the bearing outer ring, two ring-shaped guide surfaces for guiding each one Wälzkörperkäfig axially spaced from each other and each arranged circumferentially. Each guide surface acts to guide the respective Wälzkörperkäfigs with a arranged on an outer circumferential surface of the respective Wälzkörperkäfigs, ring-shaped further guide surface together. The bearing outer ring further comprises two axially spaced apart arranged on an inner circumferential surface of the bearing outer raceways for guiding one rolling element of the radial rolling bearing and at least two the bearing outer ring radially penetrating spray oil holes, which extend obliquely to a transverse plane of the bearing outer ring and into a arranged between the guide surfaces central area of the bearing outer ring open. The spray oil holes are supplied with lubricating oil via supply bores and circumferential grooves formed in the bearing housing of the exhaust gas turbocharger and the carrier rings.

The DE 10 2007 034 023 A1 shows a radial rolling bearing with a Wälzkörperkäfig and a bearing outer ring and with a cage lubricant passage, which penetrates the bearing outer ring radially. Circumferentially on the inner circumferential surface of the bearing outer ring, a guide surface is formed, on which the Wälzkörperkäfig is guided.

The DE 10 2012 211 891 A1 shows a rolling bearing for a turbocharger with an outer ring, an inner ring and with rolling elements, which are guided in a cage. The cage has on its inner circumference a guide surface which is guided on a guide track on the outer circumference of the inner ring.

The JP 2014 - 074 496 A shows a roller bearing with a lubricant supply hole in the outer ring, which meets a guided on the outer ring cage. The opening is arranged partly in the region of the guide surface and partly in the area of the rolling-body pockets.

Disclosure of the invention

The object of the invention is to improve a lubrication of a Wälzkörperkäfigführung a radial rolling bearing of a turbocharger.

This object is solved by the independent claims. Advantageous embodiments are given in the dependent claims, which in themselves or in various combinations with each other can constitute an aspect of the invention.

The radial rolling bearing according to the invention of an exhaust gas turbocharger comprises at least one ball as Wälzkörper leading Wälzkörperkäfig and at least one bearing outer ring, at least one bearing outer ring radially penetrating spray oil hole and at least one circumferentially arranged on an inner circumferential surface of the bearing outer ring, ring-shaped guide surface for guiding a Wälzkörperkäfigs of the radial rolling bearing, wherein arranged on the inner circumferential surface of the bearing outer ring outlet of the spray oil hole is partially disposed within an axial extent of the guide surface and against the guide surface by a predetermined amount axially towards a arranged on the inner lateral surface of the bearing outer raceway to Leading rolling elements is offset.

By virtue of this arrangement according to the invention of the outlet of the spray oil bore arranged on the inner lateral surface of the bearing outer ring, at least part of a lubricating oil guided through the spray oil bore can emerge from the spray oil bore directly in the region of the guide surface. As a result, the area between the guide surface and a guide surface cooperating therewith for guiding the rolling element cage is supplied with lubricating oil on an outer circumferential surface of the rolling element cage, which is accompanied by improved lubrication of the rolling element cage guide of the radial roller bearing formed thereby. As a result, the wear of a suitably equipped radial roller bearing can be reduced and consequently its life can be extended.

In addition, by the improved lubrication of Wälzkörperkäfigführung the operating characteristics of a correspondingly equipped radial rolling bearing can be improved, in particular because the improved lubrication friction losses are reduced. Furthermore, according to the invention, a lubricating oil guided through the spray oil hole is introduced into a usually relatively narrow gap between the guide surfaces of a rolling element cage guide, whereby a lubricating oil supply is throttled into the radial rolling bearing, which is accompanied by a reduction of churning losses.

Lubrication of a Wälzkörperkäfigführung according to DE 10 2010 054 904 A1 In contrast, it is based on a supply of lubricating oil, which passes into the area of the guide surfaces of the rolling element cage guide substantially at random. If, for example due to locally insufficient lubrication, no separating lubricating oil film builds up between the guide surfaces, mixed friction or even solid-body contact between the guide surfaces usually occurs. This has an increased friction and in extreme cases a relatively high wear result.

In the bearing outer ring according to the invention, the spray oil hole can be arranged offset axially in the direction of an adjacent to the guide surface raceway for rolling elements of Wälzkörperreihe. As a result, for example, in a bearing outer ring for a double row radial roller bearing a space for an arranged between the bearing outer ring and a bearing housing of an exhaust gas turbocharger or between the bearing outer ring and a support ring of a bearing cartridge Quetschölfilm increased and thereby the Quetschölfilm be extended axially. As a result, an oil flow through this space can be reduced, which is accompanied by a reduction of the lubricating oil flow as a whole. Alternatively, the axial length of the bearing outer ring or of a radial rolling bearing equipped therewith can be shortened by the aforementioned axially staggered arrangement of the spray oil bore at the same length of a Quetschölfilms, which is associated with weight advantages. In contrast, lubrication restricts a Wälzkörperkäfigführung according to DE 10 2010 054 904 A1 a margin for the positioning and dimensioning of a Quetschölfilms and for a possible reduction of the axial length of the bearing outer ring and the Radialwälzlagers clearly, especially because on the one hand the respective spray oil jet to pass the Wälzkörperkäfig laterally or radially and on the other the Quetschölfilm must have a sufficient length in order to limit the oil flow through the space provided for the arrangement of Quetschölfilms.

The bearing outer ring may also have two circumferentially arranged on the inner circumferential surface of the bearing outer ring, annular guide surfaces for guiding each of a Wälzkörperkäfig a double-row radial rolling bearing. For lubrication of two possible Wälzkörperkäfigführungen the bearing outer ring for each Wälzkörperkäfigführung at least one radially outer ring bearing oil seal have the bearing outer ring whose arranged on the inner circumferential surface of the bearing outer ring outlets are each partially disposed within an axial extent of the respective guide surface.

The outlet is partially within the axial extent of the guide surface and is offset from the guide surface by a predetermined amount axially in the direction of a arranged on the inner circumferential surface of the bearing outer raceway for guiding rolling elements. As a result, part of the outlet is outside the guide surface, so that a part of the exiting lubricating oil can be sprayed directly in the direction of the row of rolling bodies guided on the track or their rolling elements. Thus, this rolling element can be optimally lubricated, which is associated with a reduced friction in the rolling element row and consequently with improved operating characteristics of a correspondingly equipped radial roller bearing. Alternatively, the exit of the spray oil bore may be partially within the axial extent of the guide surface and axially by a predetermined amount in a direction to that described opposite direction to be arranged to the guide surface.

According to a further advantageous embodiment, the spray oil hole runs obliquely or parallel to a transverse plane of the bearing outer ring. As a result, a distribution of the lubricating oil effected in each case with the spray oil bore can be varied in order to be able to optimally adapt the lubrication of the rolling body cage guide and the respective row of rolling elements to the respective conditions and loads.

Advantageously, the bearing outer ring comprises two or more the bearing outer ring each radially penetrating, circumferentially offset from each other on the bearing outer ring arranged spray oil holes, the outlets are each partially disposed within the guide surface. Preferably, the spray oil holes are uniformly circumferentially offset from one another arranged on the bearing outer ring. The more oil spray holes are present, the more lubricating oil can be delivered to be lubricated areas of a correspondingly equipped radial roller bearing.

A further advantageous embodiment provides that the bearing outer ring has at least one additional oil hole radially penetrating the bearing outer ring, which is arranged on a portion of the bearing outer ring, which adjoins axially to an axial end of the guide surface, lying remote to a next to the guide surface the inner circumferential surface of the bearing outer ring arranged raceway is arranged to guide rolling elements of the radial rolling bearing. This also allows the lubrication of areas to be lubricated a correspondingly equipped radial roller bearing can be optimized. The additional spray oil hole may be arranged obliquely to the transverse plane of the bearing outer ring, that with her a spray oil jet can be passed partially in the direction of a next to the additional spray oil hole arranged rolling element. Preferably, the additional spray oil hole is arranged such that with it a spray oil jet can be directed to a radially outer circumferential groove on an outer circumferential surface of a bearing inner ring of the radial roller bearing, wherein the circumferential groove can deflect at least a portion of the spray oil jet in the direction of the closest arranged to the additional spray oil hole Wälzkörperreihe. The bearing outer ring may also have two or more, in particular circumferentially offset from each other, arranged additional oil splashes.

According to a further advantageous embodiment, a arranged on an outer circumferential surface of the bearing outer ring inlet of the spray oil hole is formed as a radially outer circumferential groove. This makes the use of the bearing outer ring to some extent independent of an arrangement of oil supply holes of an arranged in a bearing housing of an exhaust gas turbocharger oil gallery. According to the invention, in a bearing outer ring for a double row radial roller bearing, the two hereby commonly present radial outer circumferential grooves axially further than conventionally spaced apart, which, as described above, advantageous to the arrangement of a Quetschölfilms between the bearing outer ring and the bearing housing of an exhaust gas turbocharger or affects between the bearing outer ring and a support ring of a bearing cartridge.

A further advantageous embodiment provides that the radially outer circumferential groove also forms an inlet of the additional spray oil bore on the outer circumferential surface of the bearing outer ring. As a result, the spray oil hole and the additional spray oil hole can be supplied together with lubricating oil via the circumferential groove.

The radial rolling bearing according to the invention, in particular for an exhaust gas turbocharger, preferably comprises at least one bearing outer ring, at least one coaxially within the bearing outer ring can be arranged bearing inner ring, at least one guided between the bearing outer ring and the bearing inner ring, formed of rolling elements Wälzkörperreihe and at least one coaxially within the bearing outer ring, the rolling elements relative rolling element cage leading to each other, wherein the bearing outer ring is formed according to one of the aforementioned embodiments or any combination thereof.

With the radial rolling bearing the advantages mentioned above with respect to the bearing outer ring are connected accordingly. The radial rolling bearing can be designed as a double-row shoulder ball bearing or angular contact ball bearings. The bearing inner ring can be constructed in one or two parts in the axial direction. The rolling elements of at least one row of rolling elements may be formed as balls, rollers, barrels, needles or tapered rollers. Instead of the inner ring, a rotor shaft can be arranged to be rotatable in the bearing outer ring directly above the rows of rolling elements, wherein a corresponding outer contour with raceways is to be formed on the outer side of the rotor shaft.

The invention is not limited to the specified combination of the features of the independent claims and the dependent claims. In addition, there are other possibilities, individual features, in particular when they arise from the claims, the following description of the embodiments or directly from the figures, to each other combine. In addition, reference to the figures by the use of reference numerals is not intended to limit the scope of the claims to the illustrated embodiment examples.

• 1 eine Schnittdarstellung eines nicht unter die Erfindung fallenden Ausführungsbeispiels für ein Radialwälzlager;
• 2 eine Schnittdarstellung eines weiteren nicht unter die Erfindung fallenden Ausführungsbeispiels für ein Radialwälzlager;
• 3 eine Schnittdarstellung eines weiteren Ausführungsbeispiels für ein erfindungsgemäßes Radialwälzlager;
• 4 eine Schnittdarstellung eines weiteren Ausführungsbeispiels für ein erfindungsgemäßes Radialwälzlager;
• 5 eine Schnittdarstellung eines weiteren nicht unter die Erfindung fallenden Ausführungsbeispiels für ein Radialwälzlager; und
• 6 eine Schnittdarstellung eines weiteren nicht unter die Erfindung fallenden Ausführungsbeispiels für ein Radialwälzlager.

Preferred embodiments of the invention are explained below with reference to the accompanying drawings. These show:

• 1 a sectional view of a not falling under the invention embodiment of a radial rolling bearing;
• 2 a sectional view of another not falling under the invention embodiment of a radial rolling bearing;
• 3 a sectional view of another embodiment of an inventive radial roller bearing;
• 4 a sectional view of another embodiment of an inventive radial roller bearing;
• 5 a sectional view of another not falling under the invention embodiment of a radial rolling bearing; and
• 6 a sectional view of another not falling under the invention embodiment of a radial rolling bearing.

Detailed description of the drawings

In the figures, functionally identical components are provided with the same reference numerals.

1 shows a sectional view of an embodiment not falling under the invention for a double-row radial rolling bearing 1 for an exhaust gas turbocharger, not shown. The radial rolling bearing 1 is designed as a shoulder ball bearing. The radial rolling bearing 1 includes a bearing outer ring 2 , a coaxial within the bearing outer ring 2 arranged, two-piece bearing inner ring 3 , two between the bearing outer ring 2 and the bearing inner ring 3 guided, made of spherical rolling elements 4 formed rows of rolling elements 5 and 6 and two coaxially within the bearing outer ring 2 arranged, the rolling elements 4 the respective rolling element row 5 respectively. 6 relative to each other Wälzkörperkäfige 7 and 8th , At the bearing outer ring 2 is an oil drain hole 9 arranged. The bearing inner ring 3 has two axially adjacent ring parts 10 and 11 on. At the inner lateral surface 14 of the bearing outer ring 2 are two careers 20 and 21 arranged, at each of which a row of rolling elements 5 respectively. 6 is guided. On an outer surface 22 of the bearing inner ring 3 are two radially outer circumferential grooves 23 and 24 arranged, whose mode of action is related below 6 is clarified.

The bearing outer ring 2 two includes the bearing outer ring 2 radially penetrating spray oil holes 12 and 13 and two circumferentially on an inner circumferential surface 14 of the bearing outer ring 2 arranged, annular guide surfaces 15 and 16 for guiding one rolling element cage each 7 respectively. 8th , One on the inside surface 14 of the bearing outer ring 2 arranged outlet of the respective spray oil hole 12 respectively. 13 is completely within an axial extent of the respective guide surface 15 respectively. 16 arranged. The spray oil holes 12 and 13 run in opposite directions and obliquely to a transverse plane A of the bearing outer ring 2 , An on an outer circumferential surface 17 of the bearing outer ring 2 arranged entry of the respective spray oil hole 12 respectively. 13 is as a radially outer circumferential groove 18 respectively. 19 educated.

2 shows a sectional view of another not falling under the invention embodiment of a radial rolling bearing 1 , This embodiment differs from that in FIG 1 shown radial roller bearings 1 only in that on the bearing outer ring 2 two or more the bearing outer ring 2 each radially penetrating, two spray oil holes with evenly circumferentially offset from each other on the bearing outer ring 2 arranged spray oil holes 12 respectively. 13 forming spray oil holes 12 and 13 are arranged, whose on the inner circumferential surface 14 of the bearing outer ring 2 arranged outlets each completely within the respective guide surface 15 respectively. 16 are arranged.

3 shows a sectional view of another embodiment of an inventive radial roller bearing 1 . This embodiment differs from that in FIG 1 shown radial roller bearings 1 only by the fact that on the inner circumferential surface 14 of the bearing outer ring 2 arranged outlets of the spray oil holes 12 and 13 each partially within the axial extent of the respective guide surface 15 respectively. 16 lie and opposite the respective guide surface 15 respectively. 16 axially by a predetermined amount in the direction of the respective closest to the respective guide surface 15 respectively. 16 on the inner circumferential surface 14 of the bearing outer ring 2 arranged career 20 respectively. 21 are offset. The spray oil hole 12 is therefore further away from the spray oil hole in the axial direction 13 arranged as it is at the bearing outer ring 2 in 1 the case is.

4 shows a sectional view of another embodiment of an inventive radial roller bearing 1 . This embodiment differs from that in FIG 3 shown radial roller bearings 1 only by the fact that the spray oil holes 12 and 13 at a larger angle of inclination obliquely to the transverse plane A of the bearing outer ring 2 are arranged and that the circumferential grooves 18 and 19 have a different course in cross section, in particular a greater depth.

5 shows a sectional view of another not falling under the invention embodiment of a radial rolling bearing 1 , This embodiment differs from that in FIG 1 shown radial roller bearings 1 only by the fact that the spray oil holes 12 and 13 parallel to the transverse plane A of the bearing outer ring 2 are arranged and that the circumferential grooves 18 and 19 are formed in cross section instead of triangular rectangular.

6 shows a sectional view of another not falling under the invention embodiment of a radial rolling bearing 1 , This embodiment differs from that in FIG 5 shown radial roller bearings 1 on the one hand by the fact that the bearing outer ring 2 two the bearing outer ring 2 Radial penetrating additional spray oil holes 25 and 26 each having a portion of the bearing outer ring 2 are arranged, which axially to an axial end of the respective nearest guide surface 15 respectively. 16 connects, lying away to a nearest to the respective guide surface 15 respectively. 16 on the inner circumferential surface 14 of the bearing outer ring 2 arranged career 20 respectively. 21 is arranged.

On the other hand, the radial roller bearing differs 1 from the in 5 shown radial roller bearings 1 by the shape of the cross section of the radially outer circumferential grooves 18 and 19 on the bearing outer ring 2 , Each radially outer circumferential groove 18 respectively. 19 also forms an entry of the respective additional spray oil hole 25 respectively. 26 on the outer circumferential surface 17 of the bearing outer ring 2 out.

The additional oil spills 25 and 26 run in opposite directions and obliquely to the transverse plane A of the bearing outer ring 2 , The additional oil spills 25 and 26 are each on a radially outer circumferential groove 23 respectively. 24 on the outer circumferential surface 22 of the bearing inner ring 3 directed, wherein the circumferential grooves 23 and 24 are formed such that a respective one of them by means of the respective additional spray oil hole 25 respectively. 26 directed spray oil jet at least partially in the direction of the respective next-lying rolling body row 5 respectively. 6 and the respective closest arranged Wälzkörperkäfigs 7 respectively. 8th is diverted.

LIST OF REFERENCE NUMBERS

1

radial bearings

2

Bearing outer ring

3

Bearing inner ring

4

rolling elements

5

rolling body row

6

rolling body row

7

Rolling Element

8th

Rolling Element

9

Oil drain hole

10

ring part

11

ring part

12

Oil-drilling

13

Oil-drilling

14

Inner surface area

15

guide surface

16

guide surface

17

Outer casing surface

18

circumferential groove

19

circumferential groove

20

career

21

career

22

Outer casing surface

23

circumferential groove

24

circumferential groove

25

additional spray oil drilling

26

additional spray oil drilling

Claims (6)

Radial rolling bearing (1) of an exhaust gas turbocharger comprising at least one ball (4) as rolling elements (4) leading Wälzkörperkäfig and at least one bearing outer ring (2), with at least one bearing outer ring (2) radially penetrating spray oil bore (12, 13) and at least one circumferential an annular bearing surface (15, 16) for guiding a rolling body cage (7, 8) of the radial roller bearing (1), characterized in that an inner surface (14) ) arranged outlet of the spray oil bore (12, 13) partially within an axial extent of the guide surface (15, 16) and with respect to the guide surface (15, 16) by a predetermined amount axially in the direction of a on the inner surface (14) of the Bearing outer ring (2) arranged raceway (20, 21) for guiding rolling elements (4) is offset. Radial rolling bearing (1) according to Claim 1 , characterized in that the spray oil bore (12, 13) obliquely or parallel to a transverse plane (A) of the bearing outer ring (2). Radial rolling bearing (1) according to one of Claims 1 or 2 , characterized by two or more the bearing outer ring (2) each radially penetrating, circumferentially offset from each other on the bearing outer ring (2) arranged spray oil holes (12, 13), the outlets are each partially or completely within the guide surface (15, 16). Radial rolling bearing (1) according to one of Claims 1 to 3 characterized by at least one additional spray oil bore (25, 26) radially penetrating the bearing outer ring (2) and disposed on a portion of the bearing outer race (2) axially adjoining an axial end of the guide surface (15, 16) which removes lying to a next to the guide surface (15, 16) on the inner circumferential surface (14) of the bearing outer ring (2) arranged raceway (20, 21) for guiding rolling elements (4) of the radial rolling bearing (1) is arranged. Radial rolling bearing (1) according to one of the preceding claims, characterized in that on an outer circumferential surface (17) of the bearing outer ring (2) arranged inlet of the spray oil bore (12, 13) as a radially outer circumferential groove (18, 19) is formed. Radial rolling bearing (1) according to Claim 5 , characterized in that the radially outer circumferential groove (18, 19) also forms an inlet of the additional spray oil bore (25, 26) on the outer circumferential surface (17) of the bearing outer ring (2).

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