WO2007031160A1

WO2007031160A1 - Bearing arrangement

Info

Publication number: WO2007031160A1
Application number: PCT/EP2006/007948
Authority: WO
Inventors: Sergio Stefano Guerreiro
Original assignee: Thyssenkrupp Automotive Ag
Priority date: 2005-09-09
Filing date: 2006-08-11
Publication date: 2007-03-22
Also published as: DE102005043217A1

Abstract

The invention relates to a bearing pair having a first (1) and a second bearing body (2), wherein the first bearing body (1) is formed as a bearing seat of a crankshaft or as a piston pin which is to be mounted in a small connecting-rod eye of a connecting rod, and the second bearing body (2) is formed as a connecting-rod eye or bearing block of an engine housing, which connecting-rod eye or bearing block forms a plain bearing together with the first bearing body (1), wherein one of the bearing bodies (1, 2) has a surface coating with dry-lubricating properties, which surface coating comprises a base layer (20) made from a metal, a metal carbide or a metal alloy, and an outer covering layer (30) which has dry-lubricating properties, and wherein that surface of the other bearing body (2, 1) which faces towards the covering layer (30) has pore-like depressions (5) in which material of the covering layer (30) which has been released by abrasion can accumulate.

Description

storage

description

The invention relates to a bearing of a connecting rod on a crankshaft in the form of a connecting rod-stroke bearing or a piston pin in a connecting rod in the form of a piston pin receiving the piston bearing. Furthermore, the invention relates to a bearing of a crankshaft in a bearing shell of an engine block in the form of a crankshaft main bearing.

For the storage of crankshafts in the main crankshaft bearings and connecting rods on the crankshaft, it is known from the prior art (DE 197 00 339 C2) to use so-called main or connecting rod bearing elements in the form of bearing shells, which are used as separate components between the Crankshaft and the main bearing shell or between the crankshaft and the connecting rod are inserted. It is known from DE 197 00 339 C2 that it is advantageous to arrange so-called lubricating oil pockets distributed in the form of depressions on the actual storage area. These oil pockets are formed as recesses not connected to each other, wherein the recesses may have different shapes.

The teaching of DE 197 00 339 C2 is directed to the fact that care must be taken when introducing the lubricating oil pockets in the bearing surface on a specific, tailored to the operating viscosity of the lubricating oil sizing of the oil pockets. Only if the dimensions specified in DE 197 00 339 C2 are adhered to, it is ensured that the lubricating oil pockets completely fill with lubricant, so that in conjunction with the except for the sliding surface In operation, a hydrodynamic pressure can build up on all sides connected, tight pocket compared to the smooth surface over the sliding partner and thus surprisingly a contribution to the carrying component can be delivered by the lubricating oil bag.

According to DE 197 00 339 C2 it is provided that the lubricating oil pockets are embossed in the bearing material.

A disadvantage of the known from DE 197 00 339 C2 bearings that for this storage a separate bearing element in the form of a bearing shell is necessary. Such an additional component brings increased costs and requires the provision of additional space.

From DE 101 32 632 C1 arranged on the small connecting rod eye of a connecting rod connecting rod bearing combination with a multilayer bearing is known. In one embodiment of the invention, the bearing has at least one carrier layer and a sliding layer which is formed by a plain bearing coating applied to the carrier layer. In this document, no further details are included to the material forming the sliding bearing coating or to the method by which the sliding bearing coating can be applied to the carrier layer.

The aim of the DE 101 32 632 C1 underlying invention is to achieve a precise fine tuning of the oscillating masses of the connecting rod-piston system. This is achieved by reworking the conrod-bearing combination in the manner in the region of the small connecting-rod eye, that material is removed from a mass that corresponds to the deviation of the oscillating mass of the connecting rod-piston combination from a predetermined oscillating mass. As far as according to the above-mentioned embodiment of the invention for this purpose, the small connecting rod has a multi-layer bearing-forming plain bearing layer, so this serves in addition to their storage properties to To provide the material available, which is needed for a targeted material removal in the region of the small connecting rod for fine tuning of the oscillating masses.

Specifically described in DE 101 32 632 C1, that the sliding layer forms the inner contour of the bearing and thus the piston pin facing surface of the bearing on which the lubricant film is formed. By removing material from the sliding layer of the bearing for the purpose of fine tuning the oscillating masses, the strength of the bearing, which essentially derives from the carrier layer, is reduced only slightly. From DE 101 32 632 C1, it is also known that a resulting material removal recess in the overlay can be used as a reservoir for the liquid lubricant used.

DE 196 12 109 C1 describes a bearing component which can be used as a slide bearing component with a tribologically stressable surface. This bearing component consists of a metal-matrix-composite material whose matrix is formed by an aluminum alloy reinforced with SiC particles. The tribologically stressable surface is the surface of an anodization layer. This anodic oxide includes pits and pores, which can be filled with liquid or pasty sen lubricants such as oil or grease or solid lubricants such as PTFE, graphite, MOS ₂ or equivalent. This should give the bearing component excellent sliding and emergency running properties. The depressions and pores thus serve as lubricant depots.

From JP 2004076756 A bearing pairings between the crank pin of a crankshaft and a bearing shell and between the large connecting rod of a connecting rod and a bearing shell and between the small connecting rod of a connecting rod and a bushing for receiving the piston pin are known. In these bearing pairings, the bearing shell or the bushing can, in an exemplary embodiment, be welded to both its inner and outer surfaces. provided with a three-layer surface coating, wherein the outer layer is a W-DLC layer, the middle layer is a chromium layer and the inner layer is a nickel layer. Such a construction of the sliding bearing pairing is complicated and requires the use of bearing shells and bushes as additional components, which are additionally required in addition to the crankshaft and the connecting rod.

The invention has for its object to provide a pair of bearings according to the preamble of claim 1, which is simple and in which an additional bearing element in the form of a separate bearing shell in the case of the connecting rod-stroke bearing or the crankshaft main bearing and in the form of a socket in the case of Storage of the piston pin in the small connecting rod eye of a connecting rod can be dispensed with.

The invention is further based on the object, a method for introducing pores / depressions, which serve to receive a dry lubricant, indicate in the mutually facing, a bearing combination according to the invention forming O berflächen.

With regard to the bearing pairing, the object is achieved by a bearing pairing with the features of claim 1. Advantageous further developments are specified in the subclaims.

With regard to the method, the object underlying the invention is achieved by a method according to claim 14.

The invention is based on the finding that it is possible to dispense with a separate bearing shell in the case of bearing pair "crank pin / large connecting rod eye" or "crankshaft main bearing / bearing block of the motor housing" if one of the bearing bodies provided with a surface coating possessing dry lubrication properties with the surface coating tion comprises a base layer made of a metal alloy and an outer, dry lubricating properties possessing cover layer, and in that the cover layer facing surface of the other bearing body has pore-like depressions, in the abrasion-released material of the cover layer is storable.

The pore-like depressions are introduced directly into the surface of the bearing body facing the cover layer. The depressions or pores are used to absorb abrasion-released Dechschichtwerkstoff with dry lubrication properties. An adequate supply of the bearing combination with dry lubricant is thus ensured.

In principle, the bearing can be designed in such a way that it is a dry plain bearing in which lubrication takes place exclusively through the dry lubricant. On an additional liquid lubricant such as oil can then be waived. However, in addition to the dry lubricant of the topcoat, a liquid lubricant may also be used. If an additional liquid lubricant is used, the depressions / pores cause a hydrodynamic pressure to form between the mutually facing surfaces of the bearing bodies, as long as these surfaces move relative to one another at a sufficient relative speed. As a result, the lubrication can be further improved. However, even if the relative velocity of the surfaces moving towards one another is not sufficiently high for the formation of a hydrodynamic pressure, the recesses / pores in each case bring about an improved lubrication and lubricant supply of the bearing surfaces.

According to the invention, the bearing pair forming component surfaces are arranged directly adjacent to each other, ie without a separate bearing shell or bearing bush is provided between the component surfaces. With the invention can therefore be an additional separate bearing element in the form of a Bearing shell or bushing are completely eliminated, resulting in a cost savings.

In the invention, abrasion of the cover layer material occurs in every case and deposition of this cover layer material released by abrasion in the recesses / pores in the surface of the other bearing body, which faces the cover layer. As a result, even in the case of a dry lubrication without liquid lubricant, an adequate supply of lubricant to the bearing is ensured by the cover layer material acting as a dry lubricant. If, in addition to the thin-film material, a liquid lubricant is used (for example, oil), a sufficiently large relative movement between the bearing surfaces results in the formation of hydrodynamic lubrication between the bearing surfaces immediately adjacent to one another. If the relative speed of the bearing surfaces to one another is not sufficiently high for the formation of a hydrodynamic pressure, better lubrication of the bearing through the pores / depressions is achieved in each case.

In certain cases, it may prove useful to provide the pores / recesses not only in the component surface of the pair of bearings assigned to the cover layer, but also to provide the surface of the cover layer itself with recesses / pores. In this way, a more uniform distribution of the cover layer material and / or the liquid lubricant over the entire bearing surface can be achieved.

According to a preferred embodiment of the invention, the recesses / pores are provided in the surface of the bearing surface of the second bearing body and the surface coating is provided only on the bearing seat of the first bearing body. According to another embodiment of the invention, the conditions are exactly the opposite. As already stated above, it is in According to a further embodiment of the invention, it is also possible to provide the bearing surfaces of both bearing bodies of a bearing pair with depressions / pores.

According to the invention, the depressions / pores can advantageously be introduced by means of a blasting process. Particularly suitable for this purpose is a laser-beam method or an abrasive blasting method in which small solid particles impinge on the surfaces to be treated at high speed, so that plastic deformation and / or abrasive wear of the treated surfaces occurs due to the impact of the solid particles. In principle, however, other methods for introducing the pores / depressions in the surfaces are conceivable. By way of example, the following processes should be mentioned at this point: electroerosion, chemical etching, expansion tools (i.e., tools which, by means of expansive force, locally depress the surface to be treated to produce impressions and depressions / pores).

If the bearing is designed as a rod-type lifting bearing, then the first bearing body is designed as a crankpin of the crankshaft, on which the large connecting rod eye of the connecting rod is directly mounted. Is the storage according to the invention designed as a piston bearing, i. that is, as a bearing for a piston of an internal combustion engine on a connecting rod, the first bearing body is formed as a piston pin, which in the small connecting rod eye of the connecting rod directly, i. without interposing a bearing bush is stored. The piston pin is in this case connected to the piston, so that the piston is mounted on the piston pin in the small connecting rod eye of the connecting rod.

In order to increase the service life of a built-in crankshaft in an engine block, the invention provides that in the annular side surfaces of the connecting rod forming connecting rod portions and / or in the installed state of the connecting rod these annular side surfaces facing surface areas of the crankshaft are provided with depressions / pores. These serve in this case to receive a liquid lubricant, such as oil. In the operating state of the The internal combustion engine form the annular side surfaces of the conrod-forming connecting rod and the annular side surfaces facing surface areas of the crankshaft namely a friction pair, so that a low-wear hydrodynamic lubrication or at least improved lubrication of these facing surfaces reduces wear and thus extends the life.

Even if no liquid lubricant is used, it may be useful to form the annular side surfaces of the conrod-forming connecting rod sections and / or in the installed state of the connecting rod these annular side surfaces facing surface areas of the crankshaft with depressions / pores. In this case, it must then be ensured that at least the surface areas of the other bearing partner assigned to the depressions / pores are coated with a surface coating with dry lubrication properties. In this case, the annular side surfaces of the conrod portions forming the connecting rod and the surface areas of the crankshaft facing these annular side surfaces form a dry friction pairing (dry tribological system).

If the bearing combination according to the invention relates to the main bearing of a crankshaft, in which the bearing journals and the other main bearing portions of the crankshaft are mounted in bearing blocks of the engine block, the surface coating according to the invention is preferably provided on the bearing journal and the main bearing portions of the crankshaft, while the recesses / pores for receiving of the cover layer material released by abrasion is formed in the bearing journals / main bearing sections associated bearing surfaces of the bearing blocks of the motor housing. It is understood that a pair of bearings according to the invention can advantageously be provided at all three points at the same time, namely both on the main bearings and on the connecting rod crank bearings and on the piston bearings.

The invention also relates to a crankshaft with bearing journals and main bearing sections for the crankshaft main bearings and with crank pins for the connecting rod crank bearings, wherein at least one bearing journal and / or main bearing section and / or at least one crank journal has a surface coating with dry lubrication properties comprising a base layer comprising a metal alloy and an outer, dry lubrication possessing cover layer. A crankshaft prepared in this way is therefore likewise included in the concept of the invention because the crankshaft prepared in this way already has all the features of the coated bearing body which are necessary for forming a bearing pair according to the invention.

For the same reason, the invention is also directed to a connecting rod with a large and a small connecting rod eye, wherein the surfaces of the inner walls of the large and / or small connecting rod eye pore-like depressions for receiving abrasively released cover layer material with dry lubrication properties of the top layer of the surface coating have the Hubzapfens or the piston pin other bearing partner. Also, a connecting rod prepared in this way already contains the necessary features that are required to form a pair of bearings according to the invention between the connecting rods and the other bearing body (crank pin or piston pin).

For the application of a surface coating according to the invention, different coating methods can be used. Suitable is, for example, the PVD process (Physical Vapor Deposition) or the CVD process (Chemical Vapor Deposition). Variants of these methods, such as the PACVD method (Plasma Assisted CVD) are suitable coating methods for the Apply the surface coating. By means of the abovementioned coating methods, thin layers with a thickness in the micrometer range can be applied to the carrier surfaces.

As an alternative to the aforementioned methods, the thin film may also be applied by thermal spraying methods, such as the HVOF method (High Velocity Oxigen Fuel) or the APS method (Athmospheric Plasma Spray). Also applied with the aid of these methods thermal spray coatings meet the tribological stresses of storage and make it possible to dispense with additional bearing elements. The thin films deposited by the aforementioned thermal spray processes have a different microstructure than the thin films deposited by PVD or CVD processes. The deposited by PVD and CVD coating processes layers usually have a very dense microstructure and high hardness.

Already after a short break-in phase of storage, part of the cover layer material is transferred to the other storage partner by friction and abrasion in the invention. Since the other storage partner has pore-like depressions in its surface, the cover layer material is stored in these pores / wells, so that the pores / wells always maintain a certain amount of dry lubricant for the lubrication of the storage.

If the surface coating is formed by a DLC layer, a transfer of a carbon content of the cover layer into the pores / recesses of the texture of the other storage partner takes place. On the surface-coated bearing body remains a certain amount of carbon. A so-called "interlayer layer" is formed, which has carbon embedded in the tungsten carbide layer (WC layer), chromium nitride layer (CrN layer) or a metal alloy, in particular a chromium-based alloy, in the base layer a significant reduction of Friction and an improved tribological system with excellent sliding properties and low wear.

The base layer may, as mentioned above, be formed as a WC layer, CrN layer or as a metal alloy. The metal alloys used are preferably chromium-based alloys of the type (Cr _x : M _y ) N. For these alloys, the atomic proportion of chromium is more than 50%. As the alloying element, any metal element M may be used, wherein the concentration of the metal element M is made to satisfy the relation y [%] = 100% -x [%]. Aluminuim (AI) can be used particularly advantageously as the metal element M. Both in the case of CrN and in the case of a chromium-based alloy of the type (Cr _x : M _y ) N as the base layer, the nitrogen (N) is present as nitrogen dissolved in the metal lattice / embedded nitrogen.

The transfer of the cover layer material from the surface layer of the surface coating into the pores / recesses in the surface of the storage partner results in a reduction of the friction between the relatively moving bearing surfaces and an improved lubrication due to the incorporation of dry lubricant elements. If the dry lubricating elements are e.g. an alloy, the dry lubrication effect of these elements can be optimally utilized with the invention. The lower friction coefficient between the mutually moved bearing surfaces leads to less wear of these surfaces.

With regard to the method according to the invention for introducing the pores / recesses, it should be noted that the method according to the invention differs very clearly from the impressions of lubricating oil pockets known from the prior art (DE 197 00 339 C2). Also, the inventive method completely different from the known from DE 101 32 632 C1 method for the targeted removal of material of a certain mass a plain bearing coating for the purpose of fine-tuning the oscillating masses.

According to the invention, by means of a treatment method, which is preferably designed as a blasting method and in particular as an abrasive blasting method working with solid particles, firstly peaks and depressions are formed on the treated surface. Subsequently, the treated surface of a material-removing machining is subjected such that the tips are partially removed and the recesses partially retained. In this way, a continuous smooth and supporting surface is formed, which forms the actual storage area. In this smooth and supporting surface, the remaining wells, which are not connected to each other, arranged distributed and form the pore-like depressions for receiving exposed by abrasion cover layer material of the outer layer and possibly additionally used liquid lubricant. The inventive method is less expensive and less expensive than the known from the prior art Einprägeverfahren according to DE 197 00 339 C2 in terms of processing costs and tool costs.

In the following the invention will be explained in more detail with reference to a drawing. 1 is a schematic representation of the arrangement of crankshaft, connecting rod and

Piston of an internal combustion engine in side view, Fig. 2 a connecting rod with prepared according to the invention inner walls of

Connecting rod eyes in axial half section,

3 shows a connecting rod with prepared in accordance with the invention annular side surfaces of the connecting rod forming connecting rod sections in side view, Fig. 4 shows a crankshaft with prepared in accordance with the invention crank pin, journals and main bearing sections, 5 is an enlarged view of a provided according to the invention with pores / wells bearing body to illustrate the surface details,

Fig. 6 is a prepared for storage according to the invention bearing shell of a crankshaft main bearing in the radial half section.

7 is a sectional view of the detail X of Fig. 4th

In Fig. 1, an arrangement of the crankshaft K, connecting rod P and piston KO is shown schematically in side view. It can be seen that the connecting rod P is mounted on a crank pin H of the crankshaft K. At the end of the connecting rod P opposite the crank pin H, a piston pin B is mounted in the invisible piston rod eye concealed by the piston KO, which is connected to the piston KO. The invention relates to several bearing pairings of the arrangement shown in Fig. 1, namely on the one bearing on the large connecting rod of the connecting rod P on the crank pin H of the crankshaft K ₁ on the other to the bearing of the piston pin B in the small connecting rod eye of the connecting rod P and Also to the bearing not shown in Fig. 1 of the bearing pin 8 and the main bearing portions HP, 15 of the crankshaft K in corresponding bearing blocks, not shown, of the engine block.

In Fig. 2, a connecting rod is shown in axial half section, in which the large connecting rod 4 a and the small connecting rod 4 b are provided according to the invention with pore-like recesses 7.

In the installed state, the large connecting rod eye 4a of the connecting rod P is mounted on a crankpin H of the crankshaft K, wherein the crankpin H has a surface coating applied by a coating method. By the relative movement of the crank pin H and inner wall 5a of the large connecting rod 4a, the material of the cover layer of this surface coating rubs off during operation, so that it is released. The released cover layer material then settles in the cavities of the individual pouches. Ren / recesses 7, so that it always holds a certain amount of top layer material, which has dry lubrication properties. In this way it is ensured that the storage is always supplied with a sufficient amount of dry lubricant.

In addition to the cover layer material acting as a dry lubricant, it is also possible to provide a conventional lubricating oil supply for the bearing. The lubricating oil conventionally carried in the area of storage is also received and stored by the pores 7 formed on the inner wall 5a of the large connecting rod 4a. When installed and during operation of the crankshaft, a hydrodynamic pressure and / or improved lubrication forms between the crankpin H and the inner wall 5a of the connecting rod 4a or between the main bearing sections HP and the associated bearing shells 9 of the engine block Lubricating and low-wear bearing of the connecting rod P on the crank pin H of the crankshaft K ensures. It is understood that a corresponding hydrodynamic pressure only occurs when there is a sufficient relative speed of the mutually moving bearing surfaces.

In the connecting rod P shown in FIG. 2, the pores / depressions 7 according to the invention are also introduced into the surface of the inner wall 5b in the small connecting rod eye 4b. In the small connecting rod eye 4b, a piston pin B (not shown in FIG. 2) is mounted directly in the installed state. The surface of the piston pin B is provided with the surface coating according to the invention. The deposition of cover layer material of this surface coating in the pores / recesses 7 of the inner wall 5b of the small connecting rod 4b takes place in the same manner as described above. Again, the dry lubricating properties of the coating material are exploited. The bearing of the piston pin B in the small connecting rod 4b can also be lubricated in addition to the surface coating with dry lubrication properties by a liquid lubricant, which is supplied in a conventional manner to this bearing. In the operating state is formed - if there is a sufficient speed of the relative movement of the mutually moving bearing surfaces - between the inner wall 5b of the small connecting rod 4b and the outer surface of the piston pin B also a hydrodynamic pressure, for a safe and low-wear bearing of the piston pin B in the small connecting rod 4b ensures.

In Fig. 3 a prepared for a bearing combination according to the invention connecting rod is shown in side view. It can be seen that on the annular side surfaces 4c, 4e of the connecting rod eyes 4a, 4b forming Pleuelabschnitte pore-like recesses 7 are incorporated for receiving exposed by abrasion cover layer material of the surface coating and / or a liquid lubricant. In the same way, the pores / depressions 7 are also introduced at the rear, invisible annular side surfaces 4d and 4f of the connecting rod eyes 4a, 4b forming connecting rod sections. In the installed state of the connecting rod these annular side surfaces 4c, 4d, 4e, 4f assigned to certain surface areas of the crankshaft and form a friction pairing with these. These associated surface areas of the crankshaft are preferably likewise coated with a surface coating according to the invention, so that the cover layer material released by abrasion can deposit in these pores / depressions 7. In this way, a dry lubrication is achieved by the thin-film material at the annular side surfaces 4c, 4d, 4e, 4f, 4e, 4f of the connecting rod eyes 4a, 4b and thus ensures a safe and low-wear lubrication of this friction pairing.

As already described above for the bearing points already described, an improvement of the lubrication by the use of an additional liquid lubricant, such as oil, can also be achieved here. In this case as well, a hydrodynamic pressure can be formed in the presence of a sufficient relative speed of the mutually moving bearing surfaces, which ensures reliable lubrication of the friction pairing. The wear can be further reduced in this area and the service life can be further increased. In any case, the lubrication of the friction pair is improved, ie even if no hydrodynamic pressure is formed.

4, a crankshaft is shown in side view. The crankshaft K has bearing journals 8 with a surface 8a. Furthermore, the crankshaft K main bearing sections 15. The bearing pins 8 and the main bearing portions 15 of the crankshaft K are mounted in the installed state in bearing blocks 9 (FIG. 6), not shown, of the engine block and form the main bearings of the crankshaft. The crankshaft K shown in FIG. 4 is prepared for the inventive bearing in such a way that the surface 8a of the bearing pin 8 and the surfaces 15a of the main bearing portions 15 are coated with a surface coating according to the invention. These surface coatings are schematically indicated in FIG. 4 by a hatching of the corresponding surface regions.

In the installed state of the crankshaft K, the surfaces 8a of the bearing pin 8 and main bearing sections 15 are not shown in Fig. 4 inner walls 9a of bearing blocks 9 assigned (see Fig. 6), said bearing blocks 9 are fixedly connected to the engine block and the above already described pores / recesses 7 for receiving released by abrasion of the cover layer material of the coating.

In Fig. 4 serving as a bearing body 1 for the large connecting rod eyes of a connecting rod P Hubzapfen H are also shown, wherein the surfaces of the crank pin H are provided with the surface coating according to the invention (hatched area). In Fig. 4, only two crank pins are representative of all crank pins provided with the reference numeral H of the crankshaft K and the surface coatings are only indicated in relation to these crank pins.

According to the invention, the surface areas of the crankshaft K, which in the installed state are associated with the annular side surfaces 4c, 4d, 4e, 4f of the connecting rod sections 4a, 4b, can also be provided with the surface coating according to the invention (not visible in FIG. 4 because of the side view) to ensure between the annular side surfaces 4c, 4d, 4e, 4f and the associated surface areas of the crankshaft K an improved, safe and low-wear lubrication of this friction pair.

With reference to Fig. 5 will be explained in more detail how the pores / recesses 7 are introduced, for example, in the inner surface of the large connecting rod of a connecting rod P according to the invention. For this, the inner surface is treated with a suitable treatment method, e.g. a blasting process, in particular a working with solid particles abrasive blasting process. In this case, for example, solid particles are irradiated onto the inner surface of the connecting rod eye with a large impact velocity, so that a plastic deformation of the material and / or an abrasive wear takes place with the formation of tips 12 and depressions 13. This is schematically illustrated in the upper illustration of FIG. 5, wherein the original surface at the time before the blast treatment is represented by the solid horizontal bar and the reference numeral 2.

Subsequent to this surface treatment producing the tips 12 and depressions 13, the treated surface is subjected to a material-removing treatment, such as, for example, turning, milling or grinding or a combination of these processing methods. The tips 12 are partially removed and the recesses 13 are partially retained, so that a continuous smooth and supporting surface 14 is formed (see the lower illustration in Fig. 5). This smoothing and supporting surface 14 serves as a gerfläche that forms a bearing combination according to the invention with the coated surface of the crank pin H of a crankshaft. The remaining after the material processing in the remaining surface recesses 13 form the pores / recesses 7, which serve to receive the liberated by abrasion dry lubricant / outer layer material of the surface coating.

Fig. 6 shows a half-shell-shaped bearing block 9 of an engine block, not shown, with an inner wall 9a in the radial half section. On the circumferential inner wall 9a, the non-interconnected pores / recesses 7 are arranged distributed. With such a bearing block 9, which is fixedly connected to the engine block of an internal combustion engine and in particular integrally formed therewith, the bearing pin 8 and the other main bearing portions 15 of the crankshaft K are stored, so that bearing combination according to the invention is formed in the form of a crankshaft main bearing. As described above, the bearing journals 8 and / or the main bearing sections 15 of the crankshaft K are coated with a surface coating according to the invention with dry lubricating properties.

7 shows a sectional view of the detail marked "X" in FIG. 4. This figure merely serves to clarify the layer structure of the surface coating according to the invention, which is designed here as a DLC layer (diamond-like carbon layer). The base material G of the crankshaft, or more precisely of the crankshaft crankpin H, is applied with the surface coating consisting of the base layer 20 and the outer cover layer 30 arranged thereon The base layer 20 consists of a metal-based alloy, preferably of a chromium-based alloy The carbon of this cover layer 30 has very good dry lubrication properties The material of this cover layer 30 is released according to the invention by abrasion and embedded in the pores / depressions of the bearing surface facing this cover layer. LIST OF REFERENCE NUMBERS

1 bearing body

2 bearing bodies; surface

4 connecting rods; connecting rod

4a (big) connecting rod eye

4b (small) connecting rod eye

4c side surface

4d side surface

4e side surface

4f side surface

5a inner wall

5b inner wall

7 pores / wells

8 trunnion

8a surface

9 bearing block

9a inner wall

10 crank pins

12 tips

13 wells

14 smooth and airfoil

15 main bearing section

15a surface

20 base layer

30 topcoat

KO piston

K crankshaft

P connecting rod

H crankpin

B piston pin

Z bearing journal

HP main storage section

Claims

claims

1. Bearing pair with a first (1) and a second bearing body (2), wherein the first bearing body (1) as a bearing seat of a crankshaft or as in a small connecting rod of a connecting rod to be stored piston pin and the second bearing body (2) as a connecting rod or A bearing block of a motor housing is formed, which forms a sliding bearing with the first bearing body (1), wherein the one of the bearing bodies (1, 2) has a surface coating with dry lubrication properties, the base layer (20) of a metal, a metal carbide or a metal alloy and an outer, dry lubricant possessing cover layer (30), and wherein the cover layer (30) facing surface of the other bearing body (2, 1) has pore-like depressions (5), in the abrasively released material of the cover layer (30) can be stored.

2. bearing combination according to claim 1, wherein the surface coating by a DLC layer comprising at least two layers (diamond-like carbon layer) is formed, which is a base layer (20) of a Wo- ramcarbidschicht (WC layer) or a chromium nitride layer (CrN layer) or a chromium-based alloy and a cover layer (30) made of carbon.

3. bearing combination according to claim 1 or 2, wherein the base layer (20) is a chromium-based alloy of the type (Cr _x : M _y ) N with a Cr atomic proportion of more than 50%, where M is an arbitrary metal element whose atomic proportion the relationship y [%] = 100% - x [%] is sufficient.

4. bearing combination according to claim 3, wherein the metal element M is aluminum (AI).

5. bearing combination according to the preceding claims, wherein the surface coating by PVD (Physical Vapor Deposition) method, CVD (Chemical Vapor Deposition) method or variants of these methods such. the PACVD method (Plasma Assissted CVD) or by thermal spraying methods such as the HVOF method (High Velocity Oxygen Fuel) or the APS method (Athmospheric Plasma Spray) is applied.

6. bearing combination according to the preceding claims, wherein the pore-like depressions (5) are introduced into the bearing surface of the second bearing body (2) by blasting method using laser radiation or by mechanical abrasive blasting method.

7. bearing combination according to claim 6, wherein the pore-like depressions (5) are introduced by means of working with solid particles abrasive blasting process.

8. bearing combination according to the preceding claims, wherein the recesses (5) in relation to the thickness of the cover layer (30) are dimensioned so that after the running-in operation of the bearing pairings the recesses (5) are at least partially filled with the cover layer material and at the same time a sufficient Dry lubrication ensuring amount of top layer material on the surface of the first bearing body (1) remains.

9. bearing combination according to the preceding claims, wherein the first bearing body (1) by a crank pin (10) of the crankshaft is formed, on which the connecting rod (4) with its large connecting rod (4a) is mounted directly.

10. bearing combination according to the preceding claims, wherein the first bearing body (1) by a piston pin (11) is formed, which is in the small connecting rod (4b) of the connecting rod (4) directly mounted and connected to the piston.

11. bearing combination according to the preceding claims, wherein in the annular side surfaces (4c, 4d, 4e, 4f) of the connecting rod (4a, 4b) forming the connecting rod and / or in the installed state of the connecting rod these annular side surfaces (4c, 4d, 4e , 4f) facing surface areas of the crankshaft also pore-like depressions (5) are introduced for receiving a liquid lubricant.

12. crankshaft with bearing pin (8) and main bearing portions (15) for the crankshaft main bearings and with crank pins (10) for the connecting rod crank bearings, wherein at least one bearing pin (8) and / or main bearing portion (15) and / or at least one crank pin (10) has a dry lubricating surface coating comprising a base layer (20) of a metal alloy and an outer cover (30) having dry lubrication properties.

13. connecting rod having a large (4a) and a small connecting rod eye (4b), wherein the surfaces of the inner walls (5a, 5b) of the large and / or small connecting rod (4a, 4b) pore-like depressions (5) for receiving released by abrasion Cover layer material with dry lubricating properties from the cover layer (30) of the surface coating of the crank pin (10) or the piston pin (B) have other bearing partner.

14. A method for introducing pore-like depressions (5) for receiving exposed by abrasion cover layer material with dry lubricating properties of a cover layer (30) in the one bearing pair after Claims 1 to 10 forming surfaces (2, 5a, 5b, 8a, 8b, 9a, 15a) in which at least one of the surfaces (2, 5a, 5b, 8a, 8b, 9a, 15a) is treated by a treatment method in that tips (12) and depressions (13) form on the treated surface, the material being treated being subsequently subjected to material-removing processing such that the tips (12) are partly removed and the depressions (13) are partly retained so that a continuous smooth and supporting surface (14) is formed, which acts as a bearing surface and the remaining recesses (13) form the pore-like recesses (5) for receiving abrasively released cover layer material of the cover layer (30).

15. The method of claim 14, wherein the method of treatment is a blasting process.

16. The method of claim 13, wherein the blasting process is a solid particle abrasive blasting process in which the surface (2, 5a, 5b, 8a, 8b, 9a, 15a) is bombarded with solid particles so that the tips (12) and Form recesses (13) by plastic deformation and / or abrasive wear of the material of the treated component.

17. The method according to any one of claims 14 to 16, wherein the material-removing machining is a machining process such as turning and / or milling and / or grinding