DE102020114268A1 - Axial bearing for an axial turbocharger - Google Patents

Abstract

The invention relates to an axial bearing (1) for a shaft, in particular an axial turbocharger, with a thrust bearing (3) for the stationary fixing of the axial bearing (1) and a rotatable race (4) for receiving the shaft, which has a radial running surface (5) is received in the thrust bearing (3), the thrust bearing (3) and the race (4) each having an axial sliding surface (31, 41), with a freely rotatable bearing disk (6) between the two axial sliding surfaces (31, 41) is arranged, wherein the bearing washer (6) is rotatably arranged with a radial inner surface (7) on the radial running surface (5) of the raceway (4) and the radial inner surface (7) has at least one axial groove (9) for guiding a lubricant ( 11), and wherein the radial running surface (5) in the area of the bearing disk (6) has at least one further axial groove (10) for guiding the lubricant (11).

Description

The invention relates to an axial bearing for a shaft, in particular an axial turbocharger, with a thrust bearing for fixedly fixing the thrust bearing and a rotatable raceway for receiving the shaft, which is received in the thrust bearing with a radial running surface.

In axial turbochargers, the axial bearing for accommodating high axial thrusts usually consists of a stationary thrust bearing, a freely rotating bearing disk and a raceway that rotates at the rotor speed. The bearing disk is double-acting and has a sliding surface for both the non-rotating thrust bearing and the rotating race. The speed of the bearing disc is set due to the axial friction conditions of the sliding surfaces. The bearing disk rotates on a radial oil film of the race and is therefore radially supported. The disadvantage of this is that this radial bearing tends to be unstable. The oil supply to the bearing side or the sliding surface between the race and the bearing disk takes place through an axial profile in the rotating bearing disk. Due to a high speed difference between the raceway and the bearing washer and a radial speed component, the axial profiling of the bearing washer can become detached and there is a lack of lubrication on the radial running surface or the sliding surface between the race and the bearing washer.

It is therefore the object of the present invention to provide an axial bearing for a shaft, in particular an axial turbocharger, which improves the lubrication of the sliding surface between the race and the bearing washer.

This object is achieved by the combination of features according to claim 1.

According to the invention, an axial bearing for a shaft, in particular an axial turbocharger, with a thrust bearing for fixedly fixing the thrust bearing and a rotatable race for receiving the shaft, which is received with a radial running surface in the thrust bearing, is proposed. The thrust bearing and the raceway each have an axial sliding surface and a freely rotatable bearing disk is arranged between the two axial sliding surfaces. Furthermore, the bearing washer is rotatably arranged with a radial inner surface on the radial running surface of the raceway and the radial inner surface comprises at least one axial groove for guiding a lubricant. In addition, the radial running surface in the area of the bearing disk has at least one further axial groove for guiding the lubricant.

The advantage of this is that by reducing the profile depth in the rotating bearing disk, the instability caused by a radial speed component of the lubricating film is reduced. The axial grooves of the raceway take on a support film build-up of the lubricant of the rotating bearing disk and part of the axial oil supply for the axial sliding surface of the raceway. In this way, the lubrication of the sliding surface between the race and the bearing washer is improved.

In an advantageous embodiment variant of the invention it is provided that the at least one axial groove in the radial inner surface and the at least one further axial groove in the radial running surface have a circular cylindrical or elliptical cross section. Due to the circular cylindrical or elliptical cross section, a flow of the lubricant in the direction of the raceway and bearing washer or a supply of the corresponding sliding surface is optimized.

The axial bearing is preferably designed such that an area ratio of a cross-sectional area of the at least one further axial groove in the radial running surface to the at least one axial groove in the radial inner surface is 0.1 to 0.7. Since a lubricant consumption of the axial sliding surface between the race and the bearing disk corresponds to a shaft speed or a bearing disk speed of the respective application, in particular of the respective axial turbocharger, an adaptation of the area ratio of a cross-sectional area of the at least one further axial groove in the radial running surface to the at least one axial groove in the radial inner surface lubrication can be improved.

In one embodiment of the invention it is provided that the at least one axial groove in the radial inner surface of the bearing washer and the at least one further axial groove in the radial running surface are inclined at an angle of 0 ° to 45 ° with respect to an axis of rotation of the axial bearing to run away. The axial lubricant supply is influenced by an inclination or an inclined course and can be adapted and thus optimized to a shaft speed or a bearing disk speed of the respective application, in particular of the respective axial turbocharger.

Furthermore, an embodiment is favorable in which a longitudinal extension of the at least one further axial groove of the raceway in an axial direction of the axial bearing corresponds to an extension of the bearing disk in the axial direction. In this way, the at least one further groove of the raceway is arranged precisely in the area that is used for lubrication is particularly important because this is where the bearing washer is positioned.

In a further advantageous embodiment variant, it is provided according to the invention that the thrust bearing, the raceway and the bearing washer are made of an iron material.

In addition, a variant of the invention is favorable in which the bearing disk and the race are hardened, coated or untreated. It is advantageous that the bearing disk and the raceway can be adapted to the respective application of the axial bearing, in particular to the respective axial turbocharger, and an associated degree of purity of the lubricant.

The axial bearing according to the invention is designed in an advantageous variant that the thrust bearing integrally has a lubricant supply for the lubricant to lubricate the radial running surface of the race and the two axial sliding surfaces, preferably via a lubricant channel. The advantage of a lubricant supply integrated in the thrust bearing is that the thrust bearing is a stationary or fixed component when the thrust bearing is in the assembled state. As a result, the lubricant supply of the axial bearing can be integrated particularly easily into an already existing lubricant circuit.

In a preferred embodiment of the invention, an outlet opening of the lubricant supply is arranged on the face side towards the running surface of the raceway. As a result, the lubricant enters the axial bearing at a point at which it can be guided particularly favorably to the sliding surface between the thrust bearing and the bearing washer or the sliding surface between the race and the bearing washer or distributed between the two sliding surfaces.

In a further advantageous embodiment, it is provided according to the invention that a gap is formed between the radial inner surface and the radial running surface. Furthermore, a groove depth of at least the at least one axial groove in the radial inner surface and / or the at least one further axial groove in the radial running surface is larger in the radial direction than a gap width of the gap.

According to the invention, an axial turbocharger with at least one axial bearing with the features described above is also proposed, which comprises a shaft that is rotatably received in the at least one axial bearing. The advantage of this is that, by means of the grooves arranged in the raceway and in the rotating bearing disk, a lubricant supply to the axial bearing of the axial turbocharger is improved.

In an advantageous embodiment variant of the invention it is provided that the axial turbocharger has a housing and the respective thrust bearing is fastened to the housing for the fixed fixing of the respective axial bearing. As a result, the axial bearing is integrated and fixed in the axial turbocharger.

• 1 eine Schnittansicht eines Axiallagers für eine Welle eines Axialturboladers,
• 2 einen Querschnitt des Axiallagers für eine Welle eines Axialturboladers und
• 3 eine Schnittansicht eines Laufrings des Axiallagers für eine Welle eines Axialturboladers.

Other advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

• 1 a sectional view of an axial bearing for a shaft of an axial turbocharger,
• 2 a cross section of the axial bearing for a shaft of an axial turbocharger and
• 3 a sectional view of a race of the axial bearing for a shaft of an axial turbocharger.

In 1 Fig. 3 is a sectional view of a thrust bearing 1 shown for a shaft of an axial turbocharger. The thrust bearing 1 includes a drawer store 3 for the stationary fixation of the axial bearing 1 and to accommodate one on the thrust bearing 1 acting axial thrust. In addition, the thrust bearing 1 a rotatable race 4th to accommodate the shaft, which has a radial running surface 5 in the drawer 3 is recorded.

The drawer store 3 includes an integral lubricant supply 12th for a lubricant 11th for the lubrication of the radial running surface 5 of the raceway 4th and the two axial sliding surfaces 31 , 41 who have favourited the drawer 3 and the raceway 4th have, via a lubricant channel. The outlet opening of the lubricant supply 12th is on the face of the running surface of the raceway 4th arranged towards.

The axial bearing rotates when the axial turbocharger is in operation 1 about an axis of rotation RA and the lubricant 11th runs along the direction of the arrow.

Furthermore, there is between the two axial sliding surfaces 31 , 41 a freely rotatable bearing disc 6th positioned. The bearing washer 6th is with a radial inner surface 7th on the radial running surface 5 of the raceway 4th arranged rotatably and the radial inner surface 7th includes an axial groove 9 for guiding a lubricant 11th . It also has the radial tread 5 in the area of the bearing washer 6th another axial groove 10 for guiding the lubricant 11th on. A longitudinal extension corresponds to the further axial groove 10 in an axial direction of the thrust bearing 1 an extension of the bearing washer 6th in the axial direction.

The drawer store 3 , the raceway 4th and the bearing washer 6th of the thrust bearing 1 are made of a ferrous material. In addition, the bearing washer 6th and the raceway 4th coated.

2 shows a cross section of the in 1 shown axial bearing 1 for a shaft of an axial turbocharger. The axial groove 9 in the radial inner surface 7th and the further axial groove 10 in the radial running surface 5 have a part-circular cylindrical cross-section. Furthermore, an area ratio is a cross-sectional area of the further axial groove 10 in the radial running surface 5 to the axial groove 9 in the radial inner surface 7th about 0.3.

Furthermore is between the radial inner surface 7th and the radial running surface 5 A gap 13th educated. Here is a groove depth of the axial groove 9 in the radial inner surface 7th and the further axial groove 10 in the radial running surface 5 greater than a gap width of the gap in the radial direction 13th .

In 3 Fig. 3 is a sectional view of the raceway 4th of the thrust bearing 1 for a shaft of an axial turbocharger, in which it is shown that the further axial groove 10 in the radial running surface 5 at an angle of 40 ° with respect to the axis of rotation RA of the axial bearing 1 is inclined or runs obliquely to it.

List of reference symbols

1

Thrust bearings

3

Drawer storage

31

axial sliding surface

4th

Raceway

41

axial sliding surface

5

radial tread

6th

Bearing washer

7th

radial inner surface

9

axial groove

10

further axial groove

11

lubricant

12th

Lubricant supply

13th

gap

Claims (12)

Axial bearing (1) for a shaft, in particular an axial turbocharger, with a thrust bearing (3) for the stationary fixing of the axial bearing (1) and a rotatable race (4) for receiving the shaft, which has a radial running surface (5) in the thrust bearing ( 3) is included, wherein the thrust bearing (3) and the race (4) each have an axial sliding surface (31, 41), a freely rotatable bearing disk (6) being arranged between the two axial sliding surfaces (31, 41), wherein the bearing washer (6) is rotatably arranged with a radial inner surface (7) on the radial running surface (5) of the race (4) and the radial inner surface (7) comprises at least one axial groove (9) for guiding a lubricant (11) , and wherein the radial running surface (5) has at least one further axial groove (10) for guiding the lubricant (11) in the area of the bearing disk (6). Axial bearing (1) according to Claim 1 , characterized in that the at least one axial groove (9) in the radial inner surface (7) and the at least one further axial groove (10) in the radial running surface (5) have a partially cylindrical or partially elliptical cross section. Axial bearing (1) according to Claim 1 or 2 , characterized in that an area ratio of a cross-sectional area of the at least one further axial groove (10) in the radial running surface (5) to the at least one axial groove (9) in the radial inner surface (7) is 0.1 to 0.7. Axial bearing (1) according to one of the Claims 1 until 3 , characterized in that the at least one axial groove (9) in the radial inner surface (7) of the bearing washer (6) and the at least one further axial groove (10) in the radial running surface (5) at an angle of 0 ° to 45 ° are inclined with respect to an axis of rotation of the axial bearing (1) or run obliquely to it. Axial bearing (1) according to one of the preceding claims, characterized in that a longitudinal extension of the at least one further axial groove (10) in an axial direction of the axial bearing (1) corresponds to an extension of the bearing washer (6) in the axial direction. Axial bearing (1) according to one of the preceding claims, characterized in that the thrust bearing (3), the race (4) and the bearing washer (6) are made of an iron material. Axial bearing (1) according to one of the preceding claims, characterized in that the bearing washer (6) and the raceway (4) are hardened, coated or untreated. Axial bearing (1) according to one of the preceding claims, characterized in that the thrust bearing (3) has a lubricant supply (12) for the lubricant (11) for lubricating the radial Has running surface (5) of the raceway (4) and the two axial sliding surfaces (31, 41) integrally, preferably via a lubricant channel. Axial bearing (1) according to Claim 8 , characterized in that an outlet opening of the lubricant supply (12) is arranged on the end face towards the running surface of the raceway (4). Axial bearing (1) according to one of the preceding claims, characterized in that a gap (13) is formed between the radial inner surface (7) and the radial running surface (5), a groove depth of at least the at least one axial groove (9) in the radial inner surface (7) and / or the at least one further axial groove (10) in the radial running surface (5) is larger in the radial direction than a gap width of the gap (13). Axial turbocharger with at least one axial bearing (1) according to one of the preceding claims, characterized in that the axial turbocharger comprises a shaft which is rotatably received in the at least one axial bearing (1). Axial turbocharger according to Claim 11 , characterized in that the axial turbocharger has a housing, the respective thrust bearing (3) being fastened to the housing for the fixed fixing of the respective axial bearing (1).

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