DE102012216113A1 - Slide bearing for machine shaft, particularly camshaft or crankshaft of internal combustion engine of vehicle, comprises axial stop formed from coated circular ring insert piece, which is insertable into bearing bracket or bearing cap - Google Patents

Abstract

The slide bearing (1) comprises an axial stop (3), which is formed from a coated circular ring insert piece (4), where the coating is a diamond-like carbon coating. The slide bearing is a split slide bearing and the axial stop is a 180 degree circular ring insert piece, which is insertable into a bearing bracket (5) or a bearing cap (6). The axial stop is arranged in the bearing bracket on an opposite side of the axial stop in the bearing cap.

Description

The invention relates to a sliding bearing for a machine shaft having the features of the preamble of claim 1.

As is known, the charge cycle of a reciprocating internal combustion engine is controlled by a valve control or valve drive. The valve train is a mechanism that controls the charge cycle valves and thus the charge exchange by opening and closing the air inlet and the air outlet in the reciprocating internal combustion engine. For controlling the charge exchange valves normally a camshaft is provided, which is usually mounted in plain bearings. So that a precise axial alignment of the camshaft is ensured, a thrust bearing is additionally provided. Basically, the generic sliding bearing is a hydrodynamic bearing. The crankshaft of a reciprocating internal combustion engine usually has such a thrust bearing.

Throughout the world, new laws are forcing automakers to further meet the ever-increasing demands for minimized emissions of pollutants and noise by further developing vehicle technology, particularly engine technology such as reciprocating internal combustion engines. Rising fuel prices and increasing cost awareness among customers require improving the profitability of vehicles in order to remain competitive in the marketplace.

• – Steigerung der Lebensdauer;
• – Reduzierung der Schadstoff- und Geräuschemissionen;
• – Verbesserung des Kaltstartverhaltens;
• – Reduzierung des Kraftstoff- und Schmiermittelverbrauchs.

A key point is thus the optimization of internal combustion engines, such as the reciprocating internal combustion engine. By reducing the coefficient of friction of the internal friction of the internal combustion engine and increasing the temperature resistance while minimizing wear and corrosion of the tribologically stressed engine components, it is necessary to meet the following objectives:

• - increase the life span;
• - Reduction of pollutant and noise emissions;
• - improvement of cold start behavior;
• - Reduction of fuel and lubricant consumption.

To solve these problems, there are already numerous approaches DLC (Diamond Like Carbon) coated friction pairings in internal combustion engines to reduce friction, wear and corrosion.

This is realized, for example, by the DLC coating of entire camshaft or crankshaft bearings, or the DLC coating of a complete camshaft or bucket tappet.

The disadvantage here, however, is that the coating of large components is very expensive and expensive.

• – Mindestens ein feststehendes Lagerbauteil;
• – mindestens ein rotierendes Lagerbauteil, das relativ zum feststehenden Lagerbauteil um eine Rotationsachse drehbar gelagert ist;
• – mindestens ein Lagerspalt, der zwischen einander gegenüberliegenden Flächen der beiden Lagerbauteile ausgebildet ist und der einen mit einem Lagerfluid gefüllten Abschnitt mit mindestens einem offenen Ende aufweist, das durch ein Dichtungsmittel gegenüber der Umgebung abgedichtet ist, wobei die Lagerbauteile im Bereich des Lagerspalts einander zugewandte Lagerflächen aufweisen, die mindestens ein fluiddynamisches Lager ausbilden;
• – wobei mindestens ein Einsatzteil vorgesehen ist, das an einem Lagerbauteil angeordnet ist und eine Lagerfläche dieses Lagerbauteils ausbildet.

Another approach is exemplified by the German Offenlegungsschrift DE 10 2008 057 551 A1 , From this a fluid dynamic storage system, for example for a hard disk, is known, which has the following features:

• - At least one fixed bearing component;
• - At least one rotating bearing member which is rotatably mounted relative to the fixed bearing member about a rotation axis;
• - At least one bearing gap formed between opposing surfaces of the two bearing components and having a filled with a bearing fluid portion having at least one open end which is sealed by a sealing means to the environment, wherein the bearing components in the region of the bearing gap facing each other bearing surfaces have, which form at least one fluid dynamic bearing;
• - Wherein at least one insert part is provided, which is arranged on a bearing component and forms a bearing surface of this bearing component.

The in the DE 10 2008 057 551 A1 However, the solution shown is designed for small bearings with high speeds.

Object of the present invention is to show a plain bearing for a machine shaft, in particular a camshaft or a crankshaft of an internal combustion engine, with significantly reduced friction losses. In addition, a co-rotation of the insert should be avoided in a simple manner.

This object is solved by the features in the characterizing part of patent claim 1.

• – Kein Verdrehen des Axialanschlags möglich;
• – Reibungsreduzierung und somit Wirkungsgraderhöhung, somit Verbrauchsvorteile;
• – Verschleißvorteile und dadurch
• – Lebensdauererhöhung;
• – Geringe Materialkosten;
• – Geringe Herstellkosten, durch einfachen Fertigungsprozess (kleine Bauteile und Oberflächen);
• – Einfache Anwendung für die Massenfertigung;
• – Minimale Kosten für optimales Reibungspotential;
• – Minimales Gewicht;
• – Minimaler Bauraum;
• – Prozessvorteile im Serieneinsatz;
• – Nur die Flächen, die beschichtet werden sollen, werden auch beschichtet;
• – Platzsparender Beschichtungsprozess (Kleinstteile), dadurch hohe Stückzahlen pro Beschichtungsprozess;
• – Unabhängig von der mechanischen Nockenwellenradiallageranpassung beim Brennkraftmaschinenzusammenbau.

As a remedy of the above disadvantages, the axial bearing of the camshaft or crankshaft according to the invention is adopted by means of new components in the valve train and / or crank mechanism in the cylinder head or crankcase of the internal combustion engine. The components are friction-reducing, coated half bearing shells. For this purpose, axial recesses must be provided in the bearing block and / or bearing cap radially around the bearing bore, which act as a receptacle for the half bearing discs. The half bearing washers are used for example in a camshaft bearing in accordance with the force of the chain drive between the bearing block and camshaft. Unlike known track bearing blocks, the axial bearing is now taken over by an additional component, the half bearing disc. For example, a half bearing washer is used between the bearing block and the chain drive in the bearing block and on the side facing away from the chain drive a half bearing washer in the bearing cap. The invention thus provides half bearing washers. They are self-contained components which receive the axial force component of the camshaft bearing or crankshaft bearing. The embodiment according to the invention affords the following advantages:

• - No twisting of the axial stop possible;
• - Reduction of friction and thus increase in efficiency, thus consumption benefits;
• - Wear advantages and thereby
• - lifespan increase;
• - Low material costs;
• - Low production costs, through simple manufacturing process (small components and surfaces);
• - Easy application for mass production;
• - Minimal costs for optimal friction potential;
• - minimum weight;
• - Minimal space;
• - process advantages in series production;
• - Only the surfaces to be coated are also coated;
• - Space-saving coating process (micro parts), thus high quantities per coating process;
• - Regardless of the mechanical camshaft radial bearing adjustment in internal combustion engine assembly.

Advantageous developments of the invention are described in the subclaims.

With the embodiment according to claim 2, it is possible to arrange the axial stop according to the prevailing bearing load.

With the embodiment according to claim 3, an axial stop and a radial bearing are shown in an advantageous manner.

With the embodiment according to claim 4, the friction losses are minimized.

Preferably, a Diamond Like Carbon (DLC) coating is used.

In the following the invention with reference to two preferred embodiments in five figures is explained in more detail.

1 shows a section through a sliding bearing according to the invention.

2 shows a plan view of an inventive slide bearing without an axial stop.

3 shows a plan view of the sliding bearing according to the invention with an axial stop on the bearing block.

4 shows a plan view of the plain bearing according to the invention with an axial stop in the bearing cap.

5 shows a plan view of an inventive slide bearing with axial stop and radial bearing insert.

The following apply in the 1 to 5 the same reference numbers for the same components.

1 shows a section through an inventive, shared plain bearing 1 for a first embodiment. The plain bearing 1 is for a machine shaft 2 provided, in particular a camshaft or a crankshaft in a cylinder head, not shown, or a crankcase, not shown, of an internal combustion engine. Next, the sliding bearing 1 an axial stop 3 on, which is formed by a preferably coated 180 ° circular ring insert.

According to the invention, the sliding bearing 1 a split plain bearing and the axial stop 3 is a 180 ° -Kreisring insert, which in the present embodiment, on the one hand in a storage chair 5 and on the other hand in a bearing cap 6 can be inserted radially about an unnumbered bearing bore. For this purpose, the camp chair 5 and the bearing cap 6 one recess each 8th in which the axial stop 3 , the 180 ° circular ring insert, can be inserted. Here is the axial stop 3 with a distance a from a surface of bearing chair 5 and bearing cap 6 out. For an exact axial position of the machine shaft 2 with respect to the plain bearing 1 is a sleeve 4 intended. Due to the two-sided arrangement of the axial stops 3 An adaptation to the prevailing bearing loads is possible.

In a further embodiment, as in 5 As shown, the 180 ° circular ring insert is integral with a 180 ° radial bearing insert 7 educated. In a preferred embodiment, the axial stop is 3 coated with a Diamond Like Carbon (DLC) coating on only one functional surface (friction surface). As a result, friction and wear are significantly minimized with the above advantages.

2 shows a plan view of a three-dimensionally illustrated, inventive second embodiment of a split plain bearing 1 , A camp chair is back with 5 numbered, one Bearing cover with 6 , In the present embodiment, the bearing block 5 for inserting an axial stop 3 provided, but is not an axial stop 3 instead, only the recess is inserted 8th for the axial stop 3 recognizable, which extends axially in the depth and radially to an unnumbered bearing bore.

3 shows again the embodiment 2 , but with one in the recess 8th inserted axial stop 3 ,

4 shows again the embodiment of the 2 and 3 , however, presented from another perspective, so now an axial stop 3 , inserted in the bearing cap 6 , is recognizable.

5 shows again a view of a three-dimensionally illustrated split plain bearing 1 , with a camp chair 5 and a bearing cap 6 , In this further embodiment, the axial stop 3 in one piece with a radial bearing insert 7 executed.

LIST OF REFERENCE NUMBERS

1

bearings

2

machine shaft

3

axial stop

4

Circular ring insert

5

bearing block

6

bearing cap

7

Radial bearing insert

8th

recess

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102008057551 A1 [0008, 0009]

Claims (5)

Bearings ( 1 ) for a machine shaft ( 2 ), in particular a camshaft or a crankshaft of an internal combustion engine, with an axial stop ( 3 ), which is formed by a coated circular ring insert, characterized in that the plain bearing ( 1 ) a split plain bearing ( 1 ) and the axial stop ( 3 ) is a 180 ° circular insert, which in a bearing chair ( 5 ) and / or a bearing cap ( 6 ) can be inserted. Plain bearing according to claim 1, characterized in that an axial stop ( 3 ) in the camp chair ( 5 ) on an opposite side of an axial stop ( 3 ) in the bearing cap ( 6 ) can be arranged. Plain bearing according to claim 1 or 2, characterized in that the 180 ° circular ring insert is integral with a 180 ° radial bearing insert ( 7 ). Slide bearing according to claim 3, characterized in that the 180 ° circular ring insert and / or the 180 ° radial bearing insert are coated on a functional surface. Slide bearing according to claim 4, characterized in that the coating is a diamond-like-carbon (DLC) coating.

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