DE102008045229B4 - thrust - Google Patents

Abstract

Axial bearing for a shaft of an exhaust gas turbocharger, - with a substantially circular cylindrical axial bearing disc (1) having two opposing surfaces (2,3), and is traversed by the shaft to be supported, - wherein on both surfaces (2,3) respectively are arranged radially outwardly closed Ölzuführkanäle (5), between which in the circumferential direction wedge surfaces (6) are provided, characterized in that in the circumferential direction in each case directly adjacent to an oil feed channel (5) on both surfaces (2,3) in each case radially inward closed Ölabführkanäle (7) are arranged, which do not communicate directly with the Ölzuführkanälen (5), - that at least the Ölzuführkanäle (5), the Ölabführkanäle (7) and the wedge surfaces (6) as negative contours in the respective surface (2,3) are introduced, - that the wedge surfaces (6) radially surrounding an oil collection channel (10) is provided, which with an oil reservoir and with the individual Ölabführkanälen (7) k is communicatively connected, - that the oil collection channel (10) is introduced as a negative contour in the respective surface (2,3), - that an outer boundary formed by a positive contour (9) is provided, which prevents the oil from directly from the oil supply channel (5) in the radial direction into the oil collection channel (10), - that the oil collection channel (10) is bounded radially outwardly by a positive contour (9 ').

Description

The present invention relates to a thrust bearing for a shaft of an exhaust gas turbocharger according to the preamble of claim 1. The invention also relates to an exhaust gas turbocharger equipped with such a thrust bearing.

In modern motor vehicle construction, more and more charge devices, so-called exhaust-gas turbochargers, are used to increase the output, which have a shaft carrying a turbine wheel and a compressor wheel. Due to the very high number of revolutions of the shaft, it must be supported both in the radial direction and in the axial direction. For this purpose, so-called hydrodynamic thrust bearings are usually used, whereby lubricant, that is, in particular oil, is displaced on a wedge surface between the thrust bearing and the bearing thrust washer by rapid rotation of a bearing thrust washer. The displacement builds up an oil pressure between the thrust bearing and the bearing thrust washer, which generates an external force counteracting the axial forces. A disadvantage of such thrust bearings is that an oil guide in the thrust bearing is relatively slow, so that the existing oil for lubrication of the thrust bearing remains relatively long in the thrust bearing and due to the high rotational speed of the shaft risk overheating.

From the DE 693 09 860 T2 is a generic thrust bearing of a turbocharger known.

Another thrust bearing for an exhaust gas turbocharger is from the EP 1 619 356 A1 This thrust bearing has a disc-shaped bearing body with a central passage opening for a shaft and with at least one bearing surface surrounding the passage opening for a collar arranged on the shaft. Furthermore, on the bearing body, a leading from a radially outer region of the bearing body to the passage opening oil supply channel is provided which is formed as a groove or bore.

From the DE 196 41 673 B4 is a thrust bearing of a shaft with a substantially circular cylindrical axial bearing disc is known, which has two opposing surfaces and is traversed by the shaft to be supported. The two surfaces of the thrust washer are each arranged radially outwardly closed Ölzuführkanäle, between which wedge surfaces are provided in the circumferential direction.

From the DE 37 06 571 A1 is a thrust washer with two opposing surfaces is known, which is traversed by a shaft to be stored. On the two opposite surfaces are closed radially outward Ölzuführkanäle arranged, between which circumferentially sliding surfaces are arranged.

From the DE 32 44 893 A1 is known an axial bearing disc having wedge surfaces and locking surfaces.

From the DE 203 17 497 U1 is a generic Axiallagerscheibe known.

From the WO 02/099296 A1 is known an axial bearing disc having two opposite surfaces and is traversed by a shaft to be supported.

From the GB 829,481 In turn, a thrust washer is known. On at least one of the surfaces are closed radially outwardly Ölzuführkanäle arranged, between which wedge surfaces are provided in the circumferential direction. In the circumferential direction, in each case adjacent to an oil supply channel are radially inwardly closed Ölabführkanäle which do not communicate directly with the oil supply channels.

From the CH 399 840 A is a method for the non-cutting production of lubrication grooves in plain bearings, especially in thrust washers known.

Finally, out of the JP 63-92817 A a thrust bearing disc 1 is known which has two opposing surfaces and is traversed by a shaft to be supported.

The present invention deals with the problem for an axial bearing of the generic type to provide an improved or at least another embodiment, which is characterized in particular by an improved bearing function.

This problem is solved according to the invention by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea to provide on a thrust bearing of a thrust bearing for a shaft of an exhaust gas turbocharger radial Ölzuführ- and Ölabführkanäle, wherein the Ölzuführkanäle are arranged between wedge surfaces and provide the wedge surfaces with oil, while the Ölabführkanäle adjacent to the Ölzuführkanälen and after are completed radially inside. During operation of the thrust bearing thus oil flows through the Ölzuführkanäle on the wedge surfaces and causes there by the construction of an oil pressure the actual storage, wherein in the further course of the oil via locking surfaces directly into the Ölabführkanäle be routed and thus can be dissipated quickly. Compared to conventional thrust bearings, the thrust bearing according to the invention requires a much lower oil throughput with the same shelf life. If an equal oil throughput prevailed compared to conventional thrust bearings, the bearing effect would be significantly improved. In addition, at least the oil supply channels, the Ölabführkanäle and the wedge surfaces are introduced as negative contours in opposing surfaces of the substantially circular cylindrical thrust washer, whereby a manufacturing technology simple and thus cost-effective production of Axiallagerscheibe invention is possible. Of particular advantage, however, is that undesired bypass flows, which require a high lubricant throughput, can be avoided by means of the axial bearing washer according to the invention.

In an advantageous development of the solution according to the invention, in the circumferential direction between a respective wedge surface and an adjacent radial Ölabführkanal a locking surface is provided which is formed with respect to the wedge surface as a positive contour. The transported from the oil supply via the wedge surface on the locking surface oil there can cause the lubrication until it is discharged due to centrifugal forces or driving forces in the adjacent Ölabführkanal. Such locking surfaces thereby cause a rapid flow of the oil or lubricant used for lubrication, whereby the lubricant / oil cooling is improved for the thrust bearing.

According to the invention, an oil collection channel radially surrounding the wedge surfaces is introduced as a negative contour into the opposing surfaces of the axial bearing disk. The introduction of the oil collection channel in the surface takes place simultaneously with the introduction of the Ölzuführkanals, the Ölabführkanals and the wedge surfaces, preferably by machining, stamping or by means of metal powder injection molding process (MIM). By such a manufacturing method, the thrust washer according to the invention can manufacture simple, geometrically extremely accurate and inexpensive to produce, in particular costly rework, eg. For the production of individual channel structures, can be omitted. According to the invention, the wedge surfaces are provided radially surrounding an oil collection channel, which is communicatively connected to an oil reservoir and to the individual Ölabführkanälen. The oil collection channel is introduced as a negative contour in the respective area. It is provided by a positive contour formed outer boundary, which prevents the oil from leaking directly from the oil supply passage in the radial direction in the oil collection channel, wherein the oil collection channel is bounded radially outwardly by a positive contour.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

• 1a und c jeweils eine Ansicht auf eine erfindungsgemäße Axiallagerscheibe,
• 1b eine Schnittdarstellung durch die erfindungsgemäße Axiallagerscheibe,
• 2 eine Ansicht auf die Axiallagerscheibe.

Show, in each case schematically,

• 1a and c in each case a view of an axial bearing washer according to the invention,
• 1b a sectional view through the thrust washer according to the invention,
• 2 a view of the thrust washer.

According to the 1 , Has an inventive and substantially circular cylindrical thrust washer 1 , two opposing surfaces 2 and 3 on. Central of the thrust washer 1 is a passage opening 4 provided by which usually a shaft, not shown, for example. A shaft of an exhaust gas turbocharger, is guided. On the two surfaces 2 and 3 are each closed radially outward Ölzuführkanäle 5 arranged between which wedge surfaces in the circumferential direction 6 are arranged. Altogether are in accordance with the 1 and 2 illustrated thrust washers 1 six oil supply channels each 5 as well as six intermediate wedge surfaces 6 arranged. The term "oil", of course, other lubricants are understood below, so that the mentioned oil channels are of course understood as a general lubricant channels.

In the circumferential direction in each case adjacent to a Ölzuführkanal 5 are on both surfaces 2 and 3 in each case radially inwardly closed Ölabführkanäle 7 arranged, which not communicating with the oil supply channels 5 are connected. An oil flow during operation of the thrust washer 1 takes place as follows: First, oil passes through an inlet channel 8th (see. 1b) in the passage opening 4 and causes there lubrication between the thrust washer 1 and a shaft, not shown. The rotational movement of the shaft is through the inlet channel 8th introduced oil into the oil supply channels 5 distributed and there due to a centrifugal force with respect to the fixed thrust washer 1 rotating bearing thrust washer carried in the radial direction to the outside. An outer boundary formed by a positive contour 9 prevents the oil, directly from the Ölzuführkanal 5 in the radial direction in an oil collection channel 10 withdraw. Rather, this is in the oil supply 5 Oil transported radially outwards through the rotating bearing contact disk onto the wedge surfaces 6 transported there and forms an oil pressure required for storage. Subsequently, the oil over between a wedge surface 6 and a neighboring radial Ölabführkanal 7 located locking surface 11 the oil discharge channel 7 fed. From the oil discharge channel 7 the oil enters the wedge surfaces 6 , the oil supply channels 5 and the locking surfaces 11 surrounding oil collection channel 10 , which according to the representations in the 1a to 1c is open at the bottom and there communicates with an oil reservoir.

The oil collection channel 10 is also radially outward by a positive contour 9 ' bounded, so that in the oil collection channel 10 collected oil must inevitably flow back down into the oil reservoir. Like that 1 and 2 it can be seen extending the wedge surfaces 6 not over the entire radius of the thrust washer 1 but only up to half or to a maximum of two-thirds of the radius' of the thrust washer 1 ,

Around the thrust washer 1 on the one hand to produce as accurately as possible and on the other hand as cost-effective as possible, this example. By machining Berabeitung, embossing or metal powder injection molding process (MIM) produced. The introduction of the channels 5 . 7 and 10 as well as the wedge surfaces 6 This can be done in a single embossing process, which is much easier and therefore less expensive compared to the previous milling of these channels. With the arrow 12 according to the 1a and 1c is the direction of rotation of the bearing contact disk called. Regarding the channels made as negative contours 5 . 7 and the wedge surfaces 6 , are the locking surface 11 and optionally the border 9 and 9 ' . 9 " formed as positive contours, are thus in the axial direction on the negative contours and thereby lead to an influence on the flow direction of the oil flow. In particular, the inner boundary 9 " is optional. Of particular advantage is that by the boundaries 9 , 9 'undesirable bypass flows, which require a high lubricant throughput, can be avoided.

With the thrust washer according to the invention 1 a reduced oil flow through the thrust bearing and thereby a reduction in the oil temperature can be achieved, which has a positive effect on the bearing properties. At the same time, the thrust washers of the invention can be 1 inexpensive and simple, for example. By means of the above embossing process, produce, resulting in another advantage.

Claims (5)

Axial bearing for a shaft of an exhaust gas turbocharger, - with a substantially circular cylindrical axial bearing disc (1) having two opposing surfaces (2,3), and is traversed by the shaft to be supported, - wherein on both surfaces (2,3) respectively are arranged radially outwardly closed Ölzuführkanäle (5), between which in the circumferential direction wedge surfaces (6) are provided, characterized in that in the circumferential direction in each case directly adjacent to an oil feed channel (5) on both surfaces (2,3) in each case radially inward closed Ölabführkanäle (7) are arranged, which do not communicate directly with the Ölzuführkanälen (5), - that at least the Ölzuführkanäle (5), the Ölabführkanäle (7) and the wedge surfaces (6) as negative contours in the respective surface (2,3) are introduced, - that the wedge surfaces (6) radially surrounding an oil collection channel (10) is provided, which with an oil reservoir and with the individual Ölabführkanälen (7) is communicatively connected, - that the oil collection channel (10) is introduced as a negative contour in the respective surface (2,3), - that an outer boundary formed by a positive contour (9), which prevents the oil from directly out of the oil feed channel (5) in the radial direction into the oil collection channel (10), - that the oil collection channel (10) is bounded radially outwardly by a positive contour (9 '). Thrust bearing after Claim 1 , characterized in that in the circumferential direction between a respective wedge surface (6) and an adjacent radial Ölabführkanal (7) a locking surface (11) is provided which is formed with respect to the wedge surface (6) as a positive contour. Thrust bearing after Claim 1 or 2 , characterized in that the axial bearing disc (1) by punching, embossing or MIM process (metal injection molding) is made. Thrust bearing after one of Claims 2 or 3 , characterized in that the axial bearing disc (1) six circumferentially uniformly distributed wedge surfaces (6), locking surfaces (11), oil feed channels (5) and Ölabführkanäle (7). Exhaust gas turbocharger with at least one thrust bearing (1) according to one of Claims 1 to 4 ,

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