DE112015003625T5 - Internal combustion engine and internal combustion engine bearing, process and method of making the same - Google Patents

Abstract

This invention relates to a bearing (5) for internal combustion engines provided with a base material (10) containing iron, to which a first layer (1) and a polymer matrix surface layer (2) are applied, the first layer (1) being a bronze alloy comprising, in its composition, from 1% to 5% by volume of poured bismuth, the surface layer (2) being subject to wear and optionally the first layer (1) serving as a boundary layer between the lubricating fluid and the base material (10) , as well as a process and method of application.

Description

This invention relates to a bearing for internal combustion engines provided with a support layer based on steel which may have a low or medium carbon content, followed by a layer comprising a bismuth-containing bronze alloy and a surface layer of polymer matrix which is directly attached to the surface Bronze layer is applied to increase the durability of the bearing during operation under high pressures and in poor lubrication conditions.

General state of the art

Many developments have been made with the intention of improving load capacity and reducing, among other features, the coefficient of friction of engine components, such as bearings. On the other hand, because of the increased operating pressures of internal combustion engines, it is difficult for such attempts to be successful, as they cause premature wear in the bearing.

In addition to increased operating pressures, low viscosity lubricating oils are used to reduce friction. This results in a particularly delicate problem for bearings in an internal combustion engine, as this impairs the formation of the oil film at both low and high speeds. At high speeds, more heat is generated in the bearing and the bearing oil film becomes thinner, resulting in greater contact between the metal components. At low speeds, the formation of the oil film may be insufficient to separate the surfaces. In both cases, the life of the bearing is reduced.

Multi-layered bearings were developed with the aim of overcoming the problems mentioned. A layer construction generally comprises a solid base material, for example steel coated with a soft metal alloy, and at least one surface layer which remains in contact with the lubricating oil film.

It is important to note that not only the surface layer is important. The function of the layers is brought about by the interaction between them, each having a specific role for the performance of the bearing as well as a function with respect to the adjacent layer. Furthermore, bearings are usually provided with more than one layer to extend the life.

Usually, the first layer provides less performance in compensating for minor misalignments between the surfaces of the bearing and the surface of the crankshaft, as well as in the ability to compensate for particulates present in the oil film which result in scratches or wear on the surfaces.

In view of this problem, solutions have been proposed whose development involves multiple layers, each of which has a defined function to improve performance.

One of these solutions has the form of using two-metal or three-metal bearings. A two-metal bearing generally comprises an alloying intermediate layer and a friction-resistant layer. Three-metal bearings generally comprise a layer of bronze, followed by a diffusion barrier layer and a friction-resistant layer. In both cases, a base layer of steel is present. The main feature of these bearings is the advantage that they can withstand a high load. However, its drawback is that the surface layer of metal may have little lubrication and consequently little sensitivity to large fluctuations or discontinuities in the oil film, leading to possible deterioration of the bearing and endangering long-term performance, impairing or even interfering with the engine's function Failure leads.

The British patent GB2465852 describes a bearing comprising a first layer and a polymer surface layer. The described polymer surface layer contains friction reducing additives comprising a matrix containing: 5% to 15% by volume metal powder, preferably selected from a group comprising aluminum, copper, silver, tungsten and stainless steel, 1 Vol .-% to 15 Vol .-% of a fluoropolymer, preferably PTFE or FEP, the remainder being a polyamideimide resin with an average thickness of 9 to 12 microns. In a first embodiment, the described first layer comprises a bronze alloy containing tin and nickel, and in a second embodiment it comprises an aluminum alloy containing tin, copper, nickel and silicon in a thickness of 300 microns.

It should be noted that the main feature of the described bearing is the polymer surface layer, which undergoes minimal wear and provides higher load capacity. However, the bearing disclosed in this British patent may have reduced operability if there is excessive wear of the polymer layer. The first layer has a simpler composition and is therefore a layer with reduced operability when in contact with the shaft, being suitable for possible emergency contact situations is effective, but not as a main wear layer. If the polymer surface layer is damaged, the first layer is not adequately lubricated for the life of the bearing, reducing the adaptability to deformations and misalignments and thus reducing bearing load capacity. By combining this disadvantage with the increase in demand for higher load combustion engines, this bearing will undoubtedly have limited applicability once the first layer is exposed.

Therefore, it is necessary to have a bearing capable of ensuring excellent operability for a load between 85 MPa and 120 MPa at a competitive price, that is, the market where motors are operated with loads lower than 150 MPa and to offer a bearing having an improved life, so that when the layer responsible for the friction interface is worn, the layer immediately below it maintains the minimum friction characteristics required for performance under operating loads, that they are sufficient to ensure the stable functioning of the engine.

Objects of the invention

Therefore, it is an object of this invention to provide a bearing which is able to reconcile the various properties which are responsible for the durability of the bearing, while also achieving a higher load capacity.

It is also an object of the invention to provide a bearing comprising at least a first layer comprising a bismuth-containing bronze alloy so that this layer can serve as a non-surface surface layer with greater robustness when there is excessive wear on the polymer surface layer.

It is also an object of the invention to provide a bearing comprising at least one polymer surface layer formed among other elements of a soft metal alloy.

Finally, it is an object of the invention to provide a bearing comprising at least a first layer comprising a bronze casting alloy to improve conformability, thereby compensating for the deformations and misalignments which may occur during the useful life of the bearing become.

Brief description of the invention

This invention relates to a bearing for internal combustion engines provided with a base material containing iron, to which a first layer and a surface layer are applied, the surface layer serving as a boundary layer between the lubricating fluid and the first layer, the first layer comprising a bronze alloy comprising from 1 vol.% to 5 vol.% bismuth, the surface layer comprising a polyimideamide matrix provided with a soft metal, a fluoropolymer and a silane-based material, the surface layer being subject to wear and optionally the first layer as Boundary layer between the lubricating fluid and the base material is used.

• Phase i) plastisches Formen eines eisenhaltigen Basismaterials mit einer Dicke zwischen 1000 und 5000 Mikron;
• Phase ii) Gießen einer ersten Schicht auf das Basismaterial, wobei die erste Schicht eine Bronzelegierung umfasst, die 1 Vol.-% bis 5 Vol.-% Bismut enthält und eine Dicke zwischen 100 und 500 Mikron aufweist; und
• Phase iii) Aufspritzen einer Oberflächenschicht, die eine Polyimidamid-Polymermatrix, die mit einem Weichmetall, einem Fluorpolymer und einem Material auf Silanbasis versehen ist, umfasst, wobei die Oberflächenschicht eine Dicke zwischen 5 und 20 Mikron aufweist.

The objects of this invention also include a process for manufacturing a bearing comprising the following phases:

• Phase i) plastic forming of a base material containing iron with a thickness between 1000 and 5000 microns;
• Phase ii) casting a first layer onto the base material, the first layer comprising a bronze alloy containing 1% to 5% by volume bismuth and having a thickness of between 100 and 500 microns; and
• Phase iii) spraying a surface layer comprising a polyimideamide polymer matrix provided with a soft metal, a fluoropolymer and a silane-based material, the surface layer having a thickness between 5 and 20 microns.

This invention also relates to an internal combustion engine comprising at least one bearing as defined above.

Brief description of the drawings

This invention will be described below in more detail based on an embodiment shown in the drawings. The drawings show:

1 A bearing showing the layers according to this invention;

2 A representation of the layers of the bearing according to this invention;

3 A photograph of the layers of the bearing according to this invention.

Detailed description of the drawings

1 to 3 show a view of a warehouse 5 according to this invention in one transverse cross-section. Preferably, but not necessarily, the bearing comprises 5 According to this invention, an iron-containing base material 10 on which a first layer 1 is applied from a bismuth-containing bronze alloy. The first shift 1 takes a surface layer 2 which comprises a polyimideamide polymer matrix containing a soft metal, a fluoropolymer and a silane-based material.

With reference to the special features of the warehouse 5 According to this invention, it is stated that the base material 10 comprises an iron-containing alloy, preferably a low or medium carbon steel, in a thickness of between 1 mm and 5 mm.

In terms of the first layer 1 the composition thereof is preferably 3% to 8% tin, 1% to 5% bismuth, 0.5% to 3% nickel, with the remainder being copper, in a thickness of 100 to 500 microns.

In particular, the polymer surface layer comprises 2 a polyimideamide matrix provided with a soft metal, a fluoropolymer, and a silane-based material.

Preferably, the surface layer 2 a soft metal concentration of 1 to 14% by volume, in particular 11 to 14%, the ideal concentration being 12.5%. The soft metal may be selected from alloys of aluminum, copper, copper alloys, silver, tungsten and stainless steel.

Thus, the surface layer has 2 preferably, but not necessarily, a concentration between 2 and 8% by volume of fluoropolymer. This fluoropolymer may be selected from polytetrafluoroethylene and fluorinated ethylene propylene; Preferably, the fluoropolymer is in the surface layer 2 Polytetrafluoroethylene (PTFE) in an amount of 5.7%. It is noted that the use of this fluoropolymer reduces the friction coefficient of the bearing and improves its lubricating properties.

The polymer matrix, which is the surface layer 2 includes, also contains a silane material. These materials promote the stability of the matrix and the adhesion of the material to the first layer 1 when this is sprayed on. The surface layer 2 preferably has a concentration of 3 to 6 vol .-% of a silane material or a mixture of silane materials, in particular of 4.8%, on.

The polymer matrix in the surface layer 2 also comprises an amount of less than 0.1% of other elements, the remainder being polyimidamide, which is usually present in an amount of 77%.

Finally, the thickness of the surface layer is 2 between 5 and 20 microns, preferably a thickness of 11 microns.

The combination between the first layer 1 and the surface layer 2 of the camp 5 achieves load capacities of more than 85 MPa, alternatively withstands loads of 110 MPa, and alternatively carries loads up to a maximum of 130 MPa.

The warehouse 5 is preferably used with loads of 85 MPa to 110 MPa.

In cases where in the warehouse 5 a local disturbance, resulting from the high load and high speed, can be influenced by the polymer surface layer 2 reach out. In this regard, the construction design of the bearing works 5 according to this invention such that the layer 1 is able to dampen some of the influences that arise in the performance of its function.

The first shift 1 has bismuth in its composition, and the main function thereof is to provide solid lubrication to the bearing 5 provide when the polymer surface layer 2 Excessive wear experiences and the first shift 1 , which is made of bronze alloy, is exposed.

In addition, the presence of bismuth in the composition of the bronze casting alloy results in the first layer 1 in that during this process, the hardness required for functioning is achieved and therefore there is a higher conformability to deformations and misalignments that occur over the life of the bearing 5 may occur.

In addition to the conformability guaranteed the fact that the bearing 5 undergoes a casting process, a higher compatibility with the crankshaft of the internal combustion engine, due to its lower hardness. Thus, this invention is not only concerned with providing a first layer 1 , which can serve as an optional surface layer, but also a layer showing the behavior of the bearing 5 in operation due to the better conformability of the first layer 1 improved.

Thus, it should be noted that one of the great advantages of this invention is the application of the first layer 1 by casting, which simultaneously enhances the ability of this first layer 1 increased to exhibit improved performance when shared with the surface layer 2 acts, and, if the latter is no longer present, a lubrication function for the bearing 5 ensures what the double effect of increasing its life ensures.

Thus, it allows for the first layer 1 applied casting process, both to use bismuth in the chemical composition of the bronze alloy as well as the first layer 1 to give better shape matching properties with respect to the hardness achieved during the process.

Accordingly, the bearing points 5 According to this invention, two functional layers, as both act to the properties of the bearing 5 to improve.

These two functional layers 1 and 2 ensure a warehouse 5 which has a high load capacity.

While a preferred embodiment has been described, it should be understood that the scope of this invention includes other possible variations, which are limited only by the terms of the appended claims, and possible equivalents.

Claims (12)

Bearings for internal combustion engines, containing an iron base material ( 10 ) to which a first layer ( 1 ) and a surface layer ( 2 ) are applied, wherein the surface layer ( 2 ) as a boundary layer between a lubricating fluid and the first layer ( 1 ), the bearing ( 5 ) characterized in that the first layer ( 1 ) comprises a bronze alloy containing in its composition 1 vol.% to 5 vol.% bismuth, the surface layer ( 2 ) comprises a polyimidamide matrix provided with a soft metal, a fluoropolymer and a silane-based material, the surface layer ( 2 ) Is subject to wear and the first layer ( 1 ) optionally as a boundary layer between the lubricating fluid and the base material ( 10 ) serves. Bearing according to claim 1, characterized in that it is used in engines in which the bearings ( 5 ) are subjected to loads of less than 150 MPa, the bearing ( 5 ) Withstands a load over 85 MPa. Bearing according to claim 1, characterized in that the first layer ( 1 ) is produced by means of a casting process. Bearing according to claim 1, characterized in that the surface layer ( 2 ) is applied by spraying. Bearing according to claim 1, characterized in that the surface layer ( 2 ) from 1% to 15% by volume of soft metal, preferably from 11% to 14% by weight soft metal, especially 12.5% by volume soft metal. Bearing according to claim 1, characterized in that the soft metal in the surface layer ( 2 ) Is aluminum. Bearing according to claim 1, characterized in that the surface layer ( 2 ) from 2% by volume to 8% by volume of fluoropolymer, wherein the fluoropolymer is of the polytetrafluoroethylene (PTFE) type. Bearing according to claim 1, characterized in that the surface layer ( 2 ) from 3% to 6% by volume of silane-based material. Bearing according to claim 1, characterized in that the surface layer ( 2 ) has a thickness of 5 to 20 microns, preferably a thickness of 11 microns. Bearing according to claim 1, characterized in that the first layer ( 1 ) has a thickness of 100 to 500 microns. Process for manufacturing a warehouse ( 5 characterized in that it comprises the following phases: phase i) plastic forming of a base material containing iron ( 10 ) with a thickness between 1000 and 5000 microns; Phase ii) casting a first layer ( 1 ) on the base material ( 10 ), the first layer ( 1 ) comprises a bronze alloy containing 1% to 5% bismuth by volume and having a thickness between 100 and 500 microns; and phase iii) spraying a surface layer ( 2 ) comprising a polyimideamide polymer matrix provided with a soft metal, a fluoropolymer and a silane-based material, the surface layer ( 2 ) has a thickness between 5 and 20 microns. Internal combustion engine, characterized in that it has at least one bearing ( 5 ) according to claim 1.

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