Method for determining the wear of a bearing

Abstract

Method for determining the wear of a bearing shell (100) designed as part of a base (1200) or bearing of a rotating component (1100), namely a crankshaft (1300) or camshaft, or a piston and connecting rod pin bearing of an engine (1000), an internal combustion engine, wherein the method comprises the steps: - Introducing an annular intermediate layer (120) between a base body (130) of the bearing shell (100) and a wear-prone sliding layer (140), wherein a first intermediate layer (120) and a second intermediate layer (120) are provided, wherein the intermediate layers (120) are distinguishable from the base body (130) and the sliding layer (140), -Arranging a number of first structural elements (110) having a first geometry (G) in a first ordered pattern (150) and of second structural elements (110) having a second geometry (G) in a second ordered pattern (150) in the circumferential direction (U) in the first and second intermediate layer (120), wherein the first and second ordered patterns (150) with the arranged number of first and second structural elements (110) are configured such that the first and second acoustic feature (170) are detectable in a predetermined acoustic frequency band (180) or acoustic amplitude band (190), and - Installation of a structure-borne sound detector (1400) or similar measuring device, wherein, in the event of wear of the wear-prone sliding layer (140) up to the first and second structural element (110), the first and second structural element (110) rub against the rotating component (1100) of the motor (1000) and, due to the friction of the rotating component (1100) against the first and second structural element (110), structure-borne sound (160) is generated at the base body (130), wherein one of the structural elements (110) is made of a different material, namely a ceramic material, than the material from which the intermediate layer (120) and the sliding layer (140) are made, and - Monitoring the bearing during operation, wherein, with sufficient wear of the abrasive sliding layer (140), the number of first and second structural elements (110) generates an ordered first and second acoustic feature (170) associated with the first and second pattern (150) of first and second structural elements (110), and - Detecting the ordered first and second acoustic feature (170) assigned to the first and second pattern (150) of first and second structural elements (110) in a specified acoustic frequency band (180) or acoustic amplitude band (190) using the structure-borne sound detector (1400) or similar measuring instrument and a filter (F), and - Detection of critical wear of the bearing shell (100), since the generated first and second acoustic characteristic (170) is variable due to progressive wear, indication to stop the operation of the bearing and switch off a motor (1000) as soon as the critical wear of the bearing is detected.

Description

[0001] The invention relates to a method for determining wear of a bearing shell or similarly wear-prone bearing element of a bearing of a rotating component, namely a bearing shell of a base bearing of a rotating component of an engine, namely a crankshaft or a camshaft, or a piston and connecting rod bearing for an internal combustion engine. The bearing shell or similarly wear-prone bearing element for supporting the rotating component of the engine comprises: a base body of the bearing shell, in particular made of steel, and a wear-prone sliding layer facing the rotating component, which is designed so that the rotating component slides against it in a bearing manner, and an intermediate layer on a side of the wear-prone sliding layer facing away from the rotating component and distinguishable from the latter.

[0002] The principle is illustrated using an engine bearing shell as a key wear-prone bearing element of a bearing for a rotating component of an internal combustion engine. An internal combustion engine is fundamentally based on the conversion of a reciprocating movement caused by expansion into a rotary drive movement. The expansion is usually caused by combustion. In this way, the chemical energy of a fuel can be converted into mechanical energy. Due to constantly increasing demands on engine power, efficiency, and compact design, the engine's boundary conditions are also increasing. Among other things, the increasing mean effective pressures acting in the engine cylinders result in increased loads on engine components such as pistons, connecting rods, piston pins, and crankshaft, and in particular on the bearings used to support protruding engine components.

[0003] In particular, the crankshaft's main bearings, the camshaft bearings, and the piston and connecting rod bearings for the rotationally movable connection of the connecting rod and piston, are subject to high accelerations and forces. Effective, wear-resistant bearings at the points where relative movement occurs between the crankshaft and the engine base, between the camshaft and the engine base, and also between the piston pin and the connecting rod, are therefore of great importance. Mounting devices for these components are well known.

[0004] Generally, bearings for rotating engine components, particularly the crankshaft bearings and camshaft bearings, are designed as plain bearings. This type of bearing can also be used, for example, to provide a rotationally movable connection between a connecting rod and a piston. In a plain bearing, the two parts moving relative to one another are in direct contact. This can lead to solid / mixed friction, particularly when the bearing or engine is started. During operation, a hydrodynamic lubricating film forms. The parts moving relative to one another, particularly the bearing shell or similar wear-prone bearing element and the rotating component, slide against one another against the resistance caused by sliding friction.This can be kept low by selecting a low-friction material pairing, by lubrication, or by creating a lubricating film that separates the two contact surfaces. When the two parts touch, i.e., in the case of solid friction, which is the case with most plain bearings, wear occurs in the contact surfaces, which limits the service life.

[0005] DE 100 45 370 A1 describes a reciprocating piston engine with a plain-bearing crank mechanism and with an operating parameter of the plain bearings of the crank mechanism monitored by at least one sensor connected to an evaluation device. At least one sensor is arranged near the plain bearing to be monitored on a part of the crank mechanism that moves relative to the machine housing during operation, and the connection between the sensor and the evaluation device is routed at least partially via the crankshaft.

[0006] DE 11 2014 005 236 T5 describes a method for monitoring the presence of fretting corrosion and / or smearing with false brinelling potential in a non-rotating bearing, namely in a rolling bearing, comprising the steps of: obtaining acoustic emission data originating from the non-rotating bearing under a changing load; and comparing the acoustic emission data with a threshold value indicative of fretting corrosion and / or smearing.

[0007] In plain bearings with solid friction, low-friction material pairings are generally used. Sometimes one of the two components, such as the sliding layer, has a so-called "self-lubricating property," such as a material alloyed with lead or tin, a plastic such as PTFE, or the like. The second component, such as the crankshaft, is usually made of steel.

[0008] DE 36 21 577 A1 describes a plain bearing with a bearing layer made of bearing material mounted on a support shell. The bearing layer has groove-like recesses arranged at axial distances from one another, which are preferably filled with a plain bearing material of a different hardness than the bearing material of the bearing layer. The groove-like recesses in the bearing layer are provided only on a circumferential area of ​​the plain bearing, which corresponds to the area of ​​highest compressive load during operation and is less than half the circumference of the plain bearing.

[0009] DE 10 2016 110 858 A1 describes a plain bearing with a bearing base body made of a metallic material, with an intermediate layer made of a metallic material applied to the bearing base body, and with a plain bearing layer made of a non-metallic material applied to the intermediate layer.

[0010] Since most types of plain bearings are subject to wear and thus have a limited service life, it would be desirable to be able to reliably predict the (remaining) service life of a bearing, preferably during ongoing operation. In the event of so-called "seizure" of the bearing, i.e., complete, unnoticed consumption of the sliding layer, there is a risk of catastrophic damage to the engine or similar internal combustion engine in question. Against this background, AU 577 689 B2 discloses a method for detecting wear in a plain bearing. For this purpose, an intermediate layer is provided between a base body of the bearing shell and the sliding layer, against which the rotating component slides. This intermediate layer is also made of a different material than the base body or the sliding layer, in particular made of silver or gold.As soon as the sliding layer of the plain bearing is worn locally or completely, the abrasion of the intermediate layer begins. According to this process, abraded particles of the intermediate layer accumulate in the bearing's lubricating oil. These particles can then be detected, for example, using mass spectrometry, and thus the condition of the bearing can be determined.

[0011] This concept still requires improvement with regard to the design of the intermediate layer used - a simple, circumferential intermediate layer in the sliding bearing or a random distribution of individual measuring points consisting of silver or gold elements locally introduced into the sliding layer and the analysis method mentioned therein only allow limited and indirect reliable conclusions to be drawn about the actual degree of wear, the wear rate or even about circumferentially varying wear of the bearing.

[0012] German Patent Application DE 19 38 010 A describes a plain bearing with an inhomogeneous running layer made of at least two, preferably alloyed, materials of different hardness suitable as a bearing surface. The harder bearing material has deformation-free machining recesses on its side facing the bearing running surface, which are filled with the softer bearing material.

[0013] It would therefore be desirable to use an appropriately designed intermediate layer to directly and reliably determine the actual degree of wear, the wear rate, or even circumferentially varying wear of the bearing. In particular, it should not only be possible to determine circumferentially uneven wear of the plain bearing, but also, in an improved and reliable manner, the wear rate. Likewise, it would be advantageous to identify which bearing is worn when multiple bearings are used on a shaft.

[0014] This is where the present invention comes in, the object of which is to provide an improved method for determining wear of a bearing shell of a bearing of a rotating component of an engine, in particular in such a way that direct, reliable conclusions are obtained about the actual degree of wear, the wear rate or also about wear of the bearing that varies in the circumferential direction, preferably by means of a simpler and in particular local measuring method on the one hand about uneven wear of the plain bearing in the circumferential direction and on the other hand, in an improved manner about an existing wear rate.

[0015] The object relating to the method is achieved by the invention with the method according to claim 1 for determining wear of a bearing shell of a bearing of a rotating component of an engine.

[0016] In the method, the wear of a bearing is advantageously determined, in particular by introducing a structure-borne sound detector for detecting acoustic features which are generated by means of a pattern of structural elements in the intermediate layer due to friction on the moving component. Advantageously, this makes it possible to obtain information about the wear of the bearing and its development over time. In addition, uneven wear in the circumferential direction of the bearing can be detected. The invention is based on a bearing shell of a bearing of a rotating component such as an axle, preferably the axle of an engine, particularly preferably a base bearing of a rotating component of an engine, in particular a crankshaft or a camshaft, preferably for an internal combustion engine.

[0017] The intermediate layer of the bearing shell has a pattern with a number of structural elements, in particular an ordered or disordered pattern with a, in particular regularly or irregularly arranged, number of structural elements, wherein a structural element of the pattern is designed to rub against the rotating component of the engine as the wear-prone sliding layer wears up to the structural element, and to generate structure-borne sound on the base body due to the friction of the rotating component on the structural element, such that the number of structural elements generates an ordered acoustic feature associated with the pattern, which is detectable.

[0018] The invention is based on the idea that, to determine the wear of a plain bearing, it is advantageous to detect structure-borne noise on the base body of a bearing and use this to draw conclusions about the condition of the bearing, rather than conducting complex material concentration analyses in the lubricating oil of the bearing in question. Furthermore, a lubricating oil analysis only allows wear to be assessed for entire bearing groups, since a separate oil circuit is generally not provided for each bearing. In contrast, structure-borne noise can, in principle, be measured on any bearing of the engine in use, and thus, conclusions can be drawn about the individual condition of each bearing, provided the detected acoustic characteristic differs sufficiently from the background noise of the engine.

[0019] To this end, the invention has recognized that it is particularly advantageous to provide a pattern, in particular an ordered pattern, with a regularly arranged number of structural elements in the intermediate layer of the bearing shell. Upon sufficient wear of the wear-prone sliding layer, a number of structural elements begin to rub against the rotating component of the engine, thus generating an ordered acoustic feature on the base body of the bearing that is associated with the number of structural elements in the intermediate layer pattern and is detectable against the background noise of the engine.Thus, the invention has advantageously recognized that a pattern, in particular an ordered pattern, with a regularly arranged number of structural elements is suitable for enabling reliable conclusions to be drawn directly via the generated acoustic feature, not only on the general wear of the entire bearing, but also on questions concerning the temporal progression of the wear process as well as on questions concerning the homogeneous wear of an individual bearing of the engine in the circumferential direction.

[0020] The invention further recognizes that bearing wear analysis can be performed particularly cost-effectively and, in particular, in situ, during ongoing engine operation, by detecting structure-borne sound. In contrast, lubricating oil analysis using mass spectroscopy requires additional service intervals and is associated with significantly higher costs, particularly due to the additional equipment required.

[0021] This also leads to a bearing shell of a bearing of a rotating component of an engine and a system for determining the wear of the bearing, comprising a rotating component of an engine, a structure-borne sound detector and a bearing with a bearing shell.

[0022] The system advantageously provides for measuring the acoustic pattern generated by the pattern of the number of structural elements on the rotating component using a structure-borne sound detector. A structure-borne sound detector can be installed on one or more of the relevant engine bearings without significant design effort and thus cost-effectively, allowing reliable detection and monitoring of wear processes in the relevant bearing.

[0023] Furthermore, the system provides for the detectable acoustic feature associated with the pattern to be filtered out using a filter. This offers the advantage that the acoustic feature generated by the pattern, especially an ordered pattern, with its regularly arranged number of structural elements, can be easily separated from the background noise of the engine and subsequently detected, again using comparatively simple electronic circuits.

[0024] Within the scope of the invention, it is provided that the number of structural elements, depending on the wear of the sliding layer subject to wear, generates an ordered acoustic feature associated with the pattern, which is detectable. Specifically, this means in particular that the expected acoustic feature is provided to change depending on the wear of the sliding layer subject to wear due to the absence or incipient and then progressive friction of the structural elements on the rotating component of the engine. It is thus possible to observe the temporal development of bearing wear during operation in order to replace it in a timely manner, but not prematurely.

[0025] Advantageous further developments of the invention can be found in the dependent claims and specify in detail advantageous possibilities for realizing the concept explained above within the scope of the task and with regard to further advantages.

[0026] In particular, it is further provided that the intermediate layer is directly adjacent to the worn sliding layer or is embedded in it as part of the sliding layer. In concrete terms, this means that the intermediate layer can either be manufactured separately from the sliding layer and then fitted into the latter, or that the intermediate layer can be manufactured together with the sliding layer and integrated into it. Suitable manufacturing processes are generally used here. Furthermore, it is further provided that the intermediate layer is arranged between the base body and the sliding layer. In concrete terms, this means that it is also possible within the scope of the invention to manufacture the intermediate layer separately from the base body of the bearing shell and the sliding layer and to join the components together only in a subsequent manufacturing step.

[0027] Advantageously, the intermediate layer is directly adjacent to the base body or is embedded in the base body as part of the base body. Specifically, this means that, within the scope of the invention, it is also possible to either manufacture the intermediate layer separately from the base body of the bearing shell and then press it into the latter in an additional step, or to manufacture the intermediate layer together with the base body of the bearing shell and integrate it into it.

[0028] The three manufacturing variants described above offer the advantage of particularly flexible and therefore cost-effective production of the bearing shell according to the invention. This design freedom of the bearing shell is particularly advantageous when the bearing shell according to the invention is used in different areas of the engine. In this context, for example, the design of the plain bearing with a further developing bearing shell as either an inner or outer plain bearing is worth mentioning.

[0029] Within the scope of the invention, a first intermediate layer and a second intermediate layer are provided, wherein a first acoustic feature is generated by means of a first number of structural elements of a first pattern in the first intermediate layer, and a second acoustic feature is generated by means of a second number of structural elements of a second pattern in the second intermediate layer. This results in the advantage that a first intermediate layer could be embedded in the sliding layer, whereas a second intermediate layer could be arranged between the base body of the bearing and the sliding layer. It would thus be advantageously possible, on the one hand, to differentiate between wear of the sliding layer and wear of the intermediate layer and, on the other hand, to observe their temporal progression in order to, for example, influence the operating behavior of the engine if necessary.Furthermore, the temporal wear patterns in particular would provide opportunities to optimize future material pairings or similar in the plain bearing.

[0030] In a further development, it is also provided that the number of structural elements is a subset of the total number of structural elements. In concrete terms, this means that in the event of uneven wear of the sliding layer in the circumferential direction, only a number of structural elements can be exposed that is fewer than the total number of structural elements in the intermediate layer. This makes it possible to detect uneven wear of the bearing in the circumferential direction as well.

[0031] Within the scope of the invention, it is provided that the acoustic feature is detectable in a predetermined acoustic frequency band or an acoustic amplitude band. This offers the advantage that, through a corresponding design of the pattern with the regularly arranged number of structural elements and, if necessary, after calibration or a similar calibration process of the structure-borne sound detector, an acoustic feature characteristic of this process can be detected during the wear process of the bearing. This feature can then be separated from the background noise of the engine, for example, using simple electronic filters or the like, in a predetermined acoustic frequency band or an acoustic amplitude band and subsequently reliably detected.

[0032] Within the scope of the invention, it is further provided that with increasing wear of the sliding layer subject to wear, depending on the wear of the sliding layer subject to wear, an increasing number of structural elements are designed to generate structure-borne sound on the base body of the bearing, in particular in such a way that, depending on the wear, an ordered acoustic feature associated with the pattern is generated to an increasing extent.

[0033] In concrete terms, this results in the advantage that not only can an uneven wear process of the bearing be detected in the circumferential direction of the bearing, but that it is also possible to monitor the temporal progression of the wear process during ongoing engine operation and thus to be able to trigger a replacement of a specific bearing or similar service measures as soon as this actually becomes necessary.

[0034] Advantageously, the measure is an amplitude or frequency of the acoustic feature, or a frequency width or position of a predefined acoustic frequency band, an increasingly recognizable frequency sequence of detection frequencies, or the like. According to the invention, this results in the advantage that increasing wear of the relevant bearing can be determined based on increasing intensity or a changing characteristic of the detectable acoustic feature, which is caused by an increasing number of structural elements rubbing against the moving component of the engine. Furthermore, the diversity of the possible further development measures results in a multitude of electronic detection variants and thus the possibility of selecting the most suitable variant for the current operating conditions of the engine.

[0035] In particular, it is provided that the radial extent of the intermediate layer is greater than the radial extent of the number of structural elements, with the intermediate layer being annular and the number of structural elements being arranged in the circumferential direction. Specifically, this means that, particularly if the intermediate layer is intended as an emergency sliding layer for the rotating component of the engine, the structural elements do not have to provide immediate indication of bearing wear.

[0036] Furthermore, it is further provided that the radial extent of the intermediate layer is identical to the radial extent of the number of structural elements, whereby the intermediate layer is also circular and the number of structural elements is arranged in the circumferential direction. This means that the intermediate layer still functions as an emergency sliding layer, but is primarily intended as an indicator of the onset of bearing wear.

[0037] Furthermore, according to the invention, the radial extent of the intermediate layer is smaller than the radial extent of the number of structural elements, whereby the intermediate layer here is also circular and the number of structural elements is arranged in the circumferential direction. Specifically, this means that the structural elements can also extend into the adjacent sliding layer or the base body. This results in the advantage that by extending the structural elements into the sliding layer, wear of the latter can be detected at an early stage, and by extending into the base body, the transmission of structure-borne noise would be improved, thus improving separation from the background noise of the engine. A combination of both advantages is also conceivable.

[0038] The three manufacturing variants mentioned above offer the advantage that the bearing shell can be flexibly adapted to the specific application of the bearing. It is immediately apparent that different bearings at different locations in the engine place different demands on the design of the intermediate layer. For example, it is conceivable that for the base bearing of the engine's crankshaft, early detection of the onset of wear with a clear differentiation of the generated acoustic characteristic from the background engine noise is desirable, since damage to this bearing in particular would have catastrophic consequences for the engine.

[0039] It is advantageous if the intermediate layer is circular and the number of structural elements is arranged in the circumferential direction. It is advantageous if the number of structural elements is of the same geometry, in particular of a point-shaped and / or rounded and / or conical, e.g., oval or circular geometry, or of an angular, in particular square, rectangular, or pyramid-shaped geometry.

[0040] Thus, within the scope of a preferred development, the geometry of the number of structural elements has a constant extension in the circumferential and / or radial directions, in particular being square or rectangular, with the intermediate layer being annular and the number of structural elements being arranged in the circumferential direction. Specifically, this means that, in a further development, the structural elements are designed as square or rectangular bodies and inserted into the intermediate layer. This has the advantage that the structural elements are simple and cost-effective to manufacture, and, moreover, no complicated alignment of the structural elements relative to the other components is necessary.

[0041] In a further development, the geometry of the number of structural elements has a variable extension in the circumferential and / or radial directions, in particular being conical or pyramid-shaped, with the intermediate layer being annular and the number of structural elements arranged in the circumferential direction. This results in the advantage that, for example, with conical or pyramid-shaped structural elements, the acoustic characteristic generated by the latter changes with increasing wear in the radial direction of the structural elements. This allows conclusions to be drawn about the condition of the intermediate layer in a particularly advantageous manner.

[0042] Preferably, a structural element of the number of structural elements has a geometry and the geometry has a circumferential extension directed in the circumferential direction and / or a radius extension directed in the radial direction, wherein the circumferential extension and / or radius extension is the same for all structural elements of the number of structural elements.

[0043] Within the scope of the invention, it is provided that a first structural element has a first geometry and a second structural element has a second geometry, which are different. In particular, a first structural element can have a first geometry and a second structural element can have a second geometry in the circumferential direction. In this case, it is particularly advantageously possible, for example, to relate the onset of the wear process of the intermediate layer to the maximum service life of the latter. In a further development, this is possible by combining, for example, square and pyramid-shaped or round and conical structural elements, since the acoustic characteristic generated thereby changes with progressive wear.

[0044] In particular, a first structural element can be spaced apart from a second adjacent structural element, and the spaced apart from a further first structural element in the circumferential direction can vary from a further second adjacent structural element. Furthermore, a further development provides that the spaced apart from a first structural element relative to a second structural element can be variable in the circumferential direction. This results in the further development advantage that, given a known, circumferentially variable wear characteristic of an engine bearing, the structural elements can be arranged such that one-sided wear of the bearing in question can be detected early and thus in a timely manner.

[0045] A further advantage is that by varying the design of the structural elements of each individual bearing, different acoustic characteristics can be created for each bearing. Thus, according to the invention, it is possible to distinguish between different bearings and their wear status with a minimal number of structure-borne sound detectors. This results in direct advantages in terms of engine complexity and thus time and costs for operation and maintenance.

[0046] According to the invention, one of the structural elements is made of a different material than the material from which the intermediate layer and / or the sliding layer is made. Thus, a first structural element can also be made of a different material than a second structural element.

[0047] Within the scope of a preferred development, it is also provided that a number of structural elements are made of a different material than the material from which the intermediate layer and / or the sliding layer are made. In concrete terms, this means that the material from which the structural elements are made has different physical properties, for example a different degree of hardness, density, porosity, modulus of elasticity or the like, than the other materials used. This thus results in the advantage that the acoustic feature, which is intended to indicate the wear of the bearing in question, can also be produced in a different way, for example through particularly favorable material pairings. According to the invention, in this context, the structural element(s) is / are made of a ceramic material.

[0048] Furthermore, according to a further development, a first structural element is made of a different material than the material from which a second structural element is made. The advantage of this development arises from the fact that it again becomes possible to make statements about the onset of wear of the intermediate layer and its temporal development in an alternative way. This aspect of the invention thus enables a particularly flexible design of the bearing shell, adapted to the respective application.

[0049] A system is advantageously designed for determining the wear of a bearing, comprising a rotating component of an engine, a structure-borne sound detector, and a bearing with a bearing shell according to the concept of the invention. The system preferably has the detectable acoustic feature associated with the pattern, which can be filtered out from an acoustic environment by means of a filter.

[0050] Embodiments of the invention will now be described below with reference to the drawing. These are not necessarily intended to represent the embodiments to scale; rather, where useful for explanation, the drawing is schematic and / or slightly distorted. With regard to additions to the teachings immediately apparent from the drawing, reference is made to the relevant prior art. It should be noted that numerous modifications and changes to the form and detail of an embodiment can be made without deviating from the general idea of ​​the invention. The features of the invention disclosed in the description, in the drawing and in the claims can be essential for the further development of the invention, both individually and in any combination.Furthermore, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of ​​the invention is not limited to the exact form or detail of the preferred embodiments shown and described below, or limited to an object that would be more limited than the object claimed in the claims. For specified dimensioning ranges, values ​​within the stated limits are also intended to be disclosed as limit values ​​and to be used and claimed as desired. For the sake of simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar functions.

[0051] Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawings, which show: Fig. 1 schematically shows a preferred embodiment of an engine with a crankshaft as an example of a rotating component with a base bearing, and - as a detail - a bearing shell of the base bearing according to the concept of the invention, wherein the detectable acoustic feature is additionally shown as well as some characteristics of this acoustic feature due to a pattern, preferably an ordered pattern, with a, in particular regularly arranged, number of structural elements in an intermediate layer between the sliding layer and the base body of the bearing shell; Fig. 2 schematically shows a preferred embodiment of a system comprising an engine with a crankshaft as an example of a rotating component of the engine, a structure-borne sound detector, and a base bearing with a bearing shell for the crankshaft according to the concept of the invention; Fig. 3 schematically shows a preferred embodiment of a bearing shell, wherein the base body of the bearing shell is followed by the intermediate layer and thereafter by the sliding layer in radial extension, which extends in the circumferential direction; Fig. 4 schematically shows an enlarged view of an embodiment of the invention, in particular showing a number of structural elements; Fig. 5A - Fig. 5E is a schematic representation of preferred arrangements of a base body, an intermediate layer, a number of structural elements and a sliding layer; Fig. 6 schematic variants of patterns, here ordered patterns, with a regularly arranged number of structural elements for one embodiment.

[0052] Fig. Figure 1 shows a highly simplified schematic representation of an engine 1000 with, for example, four cylinders Z1-Z4, a crankshaft 1300, and a base bearing 1200 for supporting this shaft. Furthermore, using the base bearing as an example, a bearing shell 100 according to the concept of the invention is shown in a half-section and enlarged.

[0053] The bearing shell 100 further schematically shows a base body 130 of the bearing shell, wherein the base body is generally made of steel, and further a wear-prone sliding layer 140 of the bearing facing the rotating component 1100. This sliding layer 140 is designed so that the rotating component 1100 slides against it when the motor 1000 is in operation. Fig. 1, an intermediate layer 120 is shown on a side of the wear-prone sliding layer 140 facing away from the rotating component 1100. This intermediate layer is clearly distinguishable from the sliding layer. That is, the intermediate layer differs from the sliding layer in its physical properties, such as hardness, surface roughness, ductility, porosity, and so on.

[0054] Fig. 1 shows, in particular, that the intermediate layer 120 has an ordered pattern 150 with a, particularly regularly arranged, number of structural elements 110. According to the invention, it is these structural elements 110 of the pattern 150 that are designed to rub against the rotating component 1100 of the motor 1000 upon sufficient wear of the wear-prone sliding layer 140 up to the structural element 110. Due to the resulting friction of the rotating component 1100 against the structural element 110, structure-borne sound 160 is subsequently generated on the base body 130 of the bearing in question.

[0055] What is essential to the invention here is that the number of structural elements 110 generates an ordered acoustic feature 170 associated with the respective pattern 150. This generated acoustic feature is then clearly distinguishable from the background noise of the engine 1000 and thus relatively easy to detect.

[0056] The detectable acoustic feature 170 is at least schematically also in Fig. 1, together with a schematic representation of the relevant physical variables used according to the concept of the invention to reliably detect bearing wear. The aforementioned variables are, in particular, an amplitude 195 or frequency 185 of the acoustic feature 170, wherein it is further provided that these, in turn, can be made detectable by advantageously designing the bearing shell 100 in a predetermined acoustic frequency band 180 or an acoustic amplitude band 190. In addition, these variables depend significantly on the speed of the motor 1000 and on the actual wear state of the bearing. Alternatively, a frequency width or position of a predetermined acoustic frequency band 180, an increasingly recognizable frequency sequence of detection frequencies, or the like can also be used to detect the acoustic feature 170 according to the concept of the invention.

[0057] Fig. Figure 2 shows a system 200 for determining the wear of a bearing, wherein the system comprises a rotating component 1100 of a motor 1000, a structure-borne sound detector 1400, and a bearing, for example a base bearing 1200, with a bearing shell 100 according to the concept of the invention. Fig. The structure-borne sound detector 1400 shown in Figure 2 is intended for detecting the acoustic characteristic generated by friction between a number of structural elements on a rotating component 1100 of an engine 1000, for example, a crankshaft 1300. The acoustic characteristic detected in the aforementioned manner can then be evaluated in a control unit (S) during ongoing engine operation. Based on the continuously determined evaluation signal, a reliable conclusion can thus be drawn about the wear condition of the bearing in question.

[0058] Fig. Figure 3 schematically shows the structure of the bearing shell 100 according to a preferred embodiment. In the embodiment shown here, the intermediate layer 120 is located between an outer base body 130 of the bearing and an inner, wear-prone sliding layer 140.

[0059] But it can also - as in Fig. 5 schematically shown—it can be provided that the intermediate layer is directly adjacent to the wear-prone sliding layer 140 or is embedded in it as part of the sliding layer 140, or directly adjacent to the base body 130 or is embedded in it as part of the base body 130, whereby the intermediate layer 120 nevertheless remains clearly distinguishable with regard to the physically different properties, as stated above. The bearing shell is particularly suitable for both internal and external bearings.

[0060] Furthermore, Fig. 3 shows a coordinate system which defines, on the one hand, a radial extension (R), i.e., a radial coordinate, and, on the other hand, a circumferential direction (U), i.e., a coordinate in the circumferential direction of the bearing shell 100. The coordinates used in this context in Fig. The arrow directions shown in 3 can also be reversed if necessary.

[0061] Fig. Fig. 4 also schematically shows the structure of the bearing shell 100 according to the preferred embodiment, wherein in this illustration the ordered pattern 150 with a, in particular regularly arranged, number of structural elements 110 is also shown. Fig. 4 shows that, with sufficient wear of the wear-prone sliding layer 140, a number of structural elements are exposed. These then generate a characteristic acoustic feature 170 through friction on the rotating component 1100 of the motor 1000. Depending on the number of rubbing structural elements, the motor speed, the composition of the materials used, and so on, the bearing shell 100 allows conclusions to be drawn about the wear state of the bearing. Uneven wear in the circumferential direction can be detected in this way, and an estimation of the temporal progression of the wear process during ongoing engine operation is also possible. A replacement of the affected bearing can thus be initiated in a targeted manner.

[0062] Fig. 5A - Fig. 5E each show a schematic representation of preferred arrangements of a base body 130, an intermediate layer 120 with a number of structural elements 110 and a sliding layer 140 in a bearing shell 100.

[0063] Fig. 5A shows a first variant of a preferred arrangement 300, in which the intermediate layer 120 is embedded in the sliding layer 140 as part of the latter.

[0064] Fig. 5B shows a second variant of a preferred arrangement 310, in which the intermediate layer 120 is arranged directly adjacent to the wear-prone sliding layer 140.

[0065] Fig. 5C shows a third variant of a preferred arrangement 320, in which the intermediate layer 120 is embedded in the base body 130 as part of the latter.

[0066] Fig. 5D shows a fourth variant of a preferred arrangement 330, in which the intermediate layer 120 is arranged directly adjacent to the base body 130.

[0067] Fig. 5E shows a fifth variant of a preferred arrangement 340, in which the intermediate layer 120 is arranged between the base body 130 and the sliding layer 140.

[0068] In the Fig. 5A to Fig. 5E shows a number of structural elements 110, which are embedded in the intermediate layer 120 as part of the sliding layer 140 in accordance with the arrangement of the intermediate layer 120 ( Fig. 5A), as directly adjacent to the worn sliding layer 140 ( Fig. 5B), as part of the base body 130 ( Fig. 5C), as directly adjacent to the base body 130 ( Fig. 5D), or between the base body 130 and the sliding layer 140 are arranged completely in the intermediate layer 120.

[0069] Fig. 6 shows a non-exhaustive selection of possible geometries (G) for the shaping of the structural elements 110 of the pattern 150 of the intermediate layer 120. The Fig.The geometries (G) shown in Figure 5 can be subdivided into rounded or angular, in particular rectangular or square geometries, or into ramp-shaped, conical, or pyramid-shaped geometries. According to the invention, it is possible to vary the geometries used in the circumferential direction (U) of the intermediate layer 120, i.e., a square structural element, for example, can be followed, again for example, by a conical or pyramid-shaped structural element. It is also provided that the spacing between adjacent structural elements 110 in the circumferential direction (U) can be variable. This means that the spacing between, for example, structural elements one and two does not have to be identical to the spacing between structural elements two and three. Any embodiments are permissible here, provided they are deemed technically expedient.

[0070] Furthermore, according to the concept of the invention, it is possible to provide and space a plurality of geometrically suitable structural elements 110 in the radial direction (R). This advantageously also results in the possibility of reliably monitoring the wear process of the intermediate layer 120 in order to be able to initiate a targeted replacement of the worn bearing. A similarly advantageous effect can alternatively be achieved with conical or pyramid-shaped structural elements. By individually designing the geometry (G) of the intermediate layer 120 of each relevant bearing, it is also possible to generate an acoustic feature 170 characteristic of an individual bearing, which can then be detected by a minimum number of structure-borne sound detectors 1400.For example, it would be conceivable to design a first base bearing 1200 of a crankshaft 1300 with a combination of square and pyramid-shaped or round and conical structural elements, and to provide a second base bearing 1200 of a crankshaft 1300 with a combination of rectangular and ramp-shaped structural elements. Both base bearings would thus generate a distinguishable acoustic feature 170, which could be detected and distinguished via a common structure-borne sound detector 1400 on the crankshaft 1300. Thus, it would be possible to accurately predict which bearing needs to be replaced. List of reference symbols 100 bearing shell 110 Structural element 120 intermediate layer 130 basic bodies 140 sliding layer 150 ordered pattern 160 structure-borne sound 170 acoustic features 180 acoustic frequency band 185 Frequency 190 acoustic amplitude band 195 amplitude 200 systems 300 intermediate layer embedded in sliding layer 310 Intermediate layer adjacent to sliding layer 320 intermediate layer embedded in base body 330 Intermediate layer adjacent to base body 340 Intermediate layer between base body and sliding layer 1000 engine 1100 Rotating component 1200 basic 1300 crankshaft 1400 structure-borne sound detector F Filter G Geometry R Radial expansion U circumferential direction S control unit Z1-Z4 Cylinders 1-4

Claims

[1] Method for determining the wear of a bearing shell (100) formed as part of a base (1200) or bearing of a rotating component (1100), namely a crankshaft (1300) or camshaft, or a piston and connecting rod bearing of an engine (1000), an internal combustion engine, the method comprising the steps of: - introducing an annular intermediate layer (120) between a base body (130) of the bearing shell (100) and a wear-prone sliding layer (140), wherein a first intermediate layer (120) and a second intermediate layer (120) are provided, wherein the intermediate layers (120) of the base body (130) and the sliding layer (140) are distinguishable, -Arranging a number of first structural elements (110) having a first geometry (G) in a first ordered pattern (150) and second structural elements (110) having a second geometry (G) in a second ordered pattern (150) in the circumferential direction (U) in the first and second intermediate layers (120), respectively, wherein the first and second ordered patterns (150) with the arranged number of first and second structural elements (110) are formed such that the first and second acoustic features (170) are detectable in a predetermined acoustic frequency band (180) or an acoustic amplitude band (190), and - Installation of a structure-borne sound detector (1400) or similar measuring means, wherein upon wear of the wear-prone sliding layer (140) up to the first and second structural element (110), the first and second structural element (110) rub against the rotating component (1100) of the motor (1000) and, due to the friction of the rotating component (1100) against the first and second structural element (110), a structure-borne sound (160) is generated on the base body (130), wherein one structural element (110) of the number of structural elements (110) is made of a different material, namely a ceramic material, than the material from which the intermediate layer (120) and the material from which the sliding layer (140) are made, and - monitoring the bearing during operation, wherein, upon sufficient wear of the wear-prone sliding layer (140), the number of first and second structural elements (110) generates an ordered first and second acoustic feature (170) associated with the first and second pattern (150) of first and second structural elements (110), and - detecting the ordered first and second acoustic features (170) associated with the first and second pattern (150) of first and second structural elements (110) in a predetermined acoustic frequency band (180) or an acoustic amplitude band (190) by means of the structure-borne sound detector (1400) or similar measuring means and a filter (F), and - Detecting critical wear of the bearing shell (100) since the generated first and second acoustic feature (170) is variable due to progressive wear, displaying to stop the operation of the bearing and switching off a motor (1000) as soon as the critical wear of the bearing is detected. [2] Method according to claim 1, characterized by that the intermediate layer (120) is directly adjacent to the wear-prone sliding layer (140) (arrangement 310) or is embedded in the sliding layer (140) as part of the latter (arrangement 300). [3] Method according to claim 1 or 2, characterized by that the intermediate layer (120) is arranged between the base body (130) and the sliding layer (140) (arrangement 340). [4] Method according to one of claims 1 to 3, characterized by that the intermediate layer (120) is directly adjacent to the base body (130) (arrangement 330) or is embedded in the base body (130) as part of the latter (arrangement 320). [5] Method according to one of claims 1 to 4, characterized by that the number of structural elements (110) is a subset of a total number of structural elements (110). [6] Method according to one of claims 1 to 5, characterized by that the intermediate layer (120) is designed in such a way that with increasing wear of the wear-prone sliding layer (140), depending on the wear of the wear-prone sliding layer (140), an increasing number of structural elements (110) generate structure-borne sound (160) on the base body (130), in particular in such a way that, depending on the wear, an acoustic feature (170) associated with the pattern (150) is generated to an increasing extent. [7] Method according to claim 6, characterized by that the increasing level - an amplitude (195) or frequency (185) of the acoustic feature (170), and / or - a frequency width or position of a given acoustic frequency band (180), and / or - an increasingly recognizable frequency sequence of detection frequencies or the like. [8] Method according to one of claims 1 to 7, characterized by that the intermediate layer (120) is circular and the number of structural elements (110) is arranged in the circumferential direction (U). [9] Method according to one of claims 1 to 8, characterized by that a radial extent (R) of the intermediate layer (120) is greater than the radial extent (R) of a structural element of the number of structural elements (110) or is identical to the radial extent (R) of a structural element of the number of structural elements (110). [10] Method according to one of claims 1 to 9, characterized by that the radial extent (R) of the intermediate layer (120) is less than the radial extent (R) of a structural element of the number of structural elements (110) or is identical to the radial extent (R) of a structural element of the number of structural elements (110). [11] Method according to one of claims 1 to 10, characterized by that the number of structural elements (110) is of the same geometry, in particular of point-shaped and / or rounded, e.g. oval or circular geometry, or of angular, in particular square or rectangular or pyramid-shaped geometry. [12] Method according to one of claims 1 to 11, characterized by that a structural element of the number of structural elements (110) has a geometry and the geometry has a circumferential extent directed in the circumferential direction (U) and / or a radius extent directed in the radial direction (R), wherein the circumferential extent and / or radius extent is the same for all structural elements of the number of structural elements (110). [13] Method according to one of claims 1 to 12, characterized bythat a first structural element (110) has a distance from a second adjacent structural element (110), and the distance changes in the case of a further first structural element (110) in the circumferential direction (U) from a further second adjacent structural element (110). [14] Method according to one of claims 1 to 13, characterized by that a first structural element (110) is made of a different material than a second structural element (110).

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