EP3292520A1

EP3292520A1 - Method for computer-supported selection of machine components

Info

Publication number: EP3292520A1
Application number: EP16721160.6A
Authority: EP
Inventors: Andreas Scholzen; Simon-Martin SCHMIDT
Original assignee: Walther Flender GmbH
Current assignee: Walther Flender GmbH
Priority date: 2015-05-07
Filing date: 2016-05-06
Publication date: 2018-03-14
Also published as: WO2016177882A1; CN107580714A; DE202016008396U1; US10705512B2; US20180143620A1; CN107580714B

Abstract

The invention relates to the computer-supported selection of the respective optimal machine component for an application. In the selection, empirical values are collected in order to create a continuously improving system. According to the invention, in order to achieve this: a) features of the machine component and influencing values determining these features are determined; b) possible applications for the machine component are determined; c) for the machine components, the influencing values to be taken into consideration in the application-related selection and designing of the machine component are determined, to which the machine component is subject during application; d) in practical application or via experimental investigations, statements relating to the influencing variables are collected, and information relating to the interactions of the influencing variables is determined from the collected statements; e) the information determined in working step d) is stored as machine-readable data in a database; f) the influencing variables arising during application are formulated for the selection of the machine component that is suitable for the provided application; g) the application and the associated influencing variables are stored as input variables in a selection algorithm running on a computer, which selects the machine component that is optimally suitable for the application, taking into consideration the input variables based on the information stored in the database; and h) the machine component selected in working step g) is supplied for the provided application.

Description

Method for computer-assisted selection of machine components

The invention relates to a method with which computer-assisted machine components can be determined which are particularly suitable for a particular particular application.

As a "machine component", individual machine elements or groups of specific aggregates are subsequently interacted with each other

Machine elements understood. The considered machine elements are each a smallest technical functional unit which is suitable for meeting the technical-functional requirements resulting from the particular technical application under consideration. The term "machine component" accordingly also includes the components, starting materials or process parameters used in the manufacture of machine components or their machine elements, since the properties and functions of the components and elements considered here always depend on the manner of their manufacture and the materials used therein Process be coined.

At present, machine components are usually designed according to the respective application according to standardized methods. This approach is simple, proven, and secure because it flat-rates individual differences in applications

"Safety factors" safeguards.

This selection and interpretation system is described, for example, in "Maschinenelemente 2, Prof. Schlecht", Addison-Wesley Verlag, Edition: 2 (1 November 2009), ISBN 13: 978-3827371461, or "Maschinenelemente, Roloff / Matek" Springer Vieweg; Edition: 21st, complete, revised. Edition 2013 (August 9, 2013), ISBN-13. 978-3658023263, explained in more detail.

A typical example of machine components that may be selected in the manner contemplated and recited herein are belts for belt drives. The selection of such belts usually takes place in accordance with VDI Guideline 2758

"Belt transmission" from June 1993. The conventional approach to the application-based selection of such

Machine elements from catalog-provided machine elements, in particular produced according to a specific manufacturer specification, can be summarized as follows (see also attached FIG.

(a) The choice made by the intended application and the selection of the

Machine element to be considered conditions. These conditions include, for example, the static and dynamic loads to which the machine element will be exposed during operation, as well as external ones

Conditions such as ambient atmosphere, temperatures, friction pairings,

Machine concept, etc., under which the machine element is to be used.

(b) The designer places himself on the basis of the machine concept

certain type of machine element.

(c) c.1 For the machine element type specified under (b), the power values to be provided by this type of machine element are calculated based on the conditions to be considered (a). c.2 The calculated power values are subject to safety margins to:

Inaccuracies of the performance value calculation (b) or in unforeseeable uncertainties occurring in practical use.

(d) Based on the performance values assigned with safety margins, the

catalog-provided machine elements selected for the intended use machine element.

The steps (c) and (d) are usually represented by tables or graphs, alternatively by a suitable software, on the basis of which to be taken into account conditions (a) and in accordance with the decision made in step (b) from the relevant machine element can be determined in each case to be provided.

Although this method of interpretation, which is expedient in practice but based on comparably rough estimates, has the following limitations and disadvantages:

- A predefinition is made to a specific type of machine element.

The view in the further design and selection of the appropriate machine element is accordingly limited to this one machine element type. alternative Machine elements which could possibly better solve the respective drive task within the framework of the given machine concept, are due to the

Preliminary determination in the further consideration no longer considered.

- The expected life of each machine element life can not be considered in the selection and design, since the selection is backed by such high safety factors that the theoretically achievable life of the machine element is far higher than the required or desired in practice life.

- The closer determination and design of the machine element is usually carried out as a function of less influencing variables. The consideration of several different, but mutually conditional or influencing selection criteria is not possible due to the associated computational effort in the rule.

- The specific design of the selected machine element is usually without regard to the influencing factors caused by the application. At best, such influencing factors are included roughly on a flat-rate basis.

- The design is always carried out with very high levels of certainty to cover unknown or individually not taken into account with sufficient certainty.

- The over-dimensioning that ensues as a result of the lump-sum provisioning and protection through security surcharges leads to an unnecessary increase in the cost of the respective

Machine element.

- The performance capabilities of the machine elements are not optimally used. By standardizing and safeguarding through security premiums, solutions that could be used with great success in practice are not feasible.

With regard to an application in which driving forces are to be transmitted to a component to be moved, this means that the designer initially sets himself, for example, on "belts" as traction means of his choice. As a result, he no longer considers alternative traction means or drives in his further considerations, which could possibly better solve the drive task.

The design of endless toothed belts then takes place on the basis of performance values given in catalogs, which the belt manufacturers generally, that is, not application-related, publish. The information of different manufacturers to those offered by them

Drive belts are not comparable with each other because it is not clear on what basis the information was determined. In particular, it is not known on which lifespan basis the values have been set. Detailed guidelines or standards on how comparable performance values can be determined do not currently exist. Instead, manufacturers of drive belts define their own calculation and design methods. As a result, the characteristics and selection criteria given by the different manufacturers are not or at best comparable with great effort and considerable uncertainty. This is how products with seemingly similar appear

Property profiles often not as interchangeable, because the specified properties have been determined in different ways.

A rough specification for the calculation of the requirements that drive belts have to meet is found in guideline VDI 2758. It states in section 3: "The belt drive must meet the given requirements and operating conditions (speeds, torques, space requirements, overloads, shaft misalignments) , Temperatures and other environmental conditions) to function safely for a reasonable amount of time and, on the other hand, to minimize the impact on the environment (noise, vibration, etc.). " How these requirements can be met with optimum utilization of the power potentials brought along by the respective drive belt remains open.

The present invention has set itself the goal of specifying a method that allows the systematic and targeted selection of the most suitable for a particular application machine component, which should be included in this selection empirical values, so as to a constantly improving system automatically create.

The invention has achieved this object by the method specified in claim 1.

Advantageous embodiments of the invention are specified in the dependent claims and are explained below as the general inventive concept in detail.

The procedure proposed by the invention is shown in FIG. 1 in the form of a diagram.

Accordingly, a method according to the invention for the computer-aided selection of a machine component provided for a specific use comprises at least the following working steps: a) Properties of the respectively considered machine component and influencing variables determining these properties are determined. b) Possible applications are determined for the particular machine component considered. c) For the respectively considered machine component, those at the

determined application-related selection and interpretation of the machine component to be considered influencing variables to which it is exposed in their respective use. d) They are used in practical or systematic experimental

Investigations of the machine components Information on the influencing variables recorded and from the recorded statements information about the interactions of the influencing variables determined. e) The information obtained in step d) on the interactions is fed into a database as machine-readable data. f) For the selection of suitable for the intended use

Machine components are formulated in terms of the intended use. g) The use and the associated influencing variables are fed as input variables into a selection algorithm running on a computer, which, taking into account the input variables on the basis of the information stored in the database, optimally fits the respective application

Machine component selects. h) The selected in step g) machine component is supplied to the intended use.

In the method according to the invention, properties and the influencing variables determining these properties are thus determined in the first working step for the particular machine component considered.

Then the applications in question are determined for the particular machine component under consideration and it is determined to which influencing variables the machine component is exposed during the respective use and which influencing variables are accordingly to be considered in the application-related selection and design of the machine component. In a following step, the interactions of the influencing variables are determined from statements that have been made on the influencing variables in practical use of the considered machine component, or from statements which are based on the influencing variables and obtained by systematic experimental investigations. If it turns out that as such, previously unidentified influencing factors exist, then these newly recognized influencing variables can be compared to the group of factors to be considered and

Be added interaction with other standing factors.

If the product- or application-specific interactions can be described formulaically with a rule, then this rule is formulated. Alternatively or in addition, the interactions may also take the form of fuzzy descriptions ("fuzzy logic", artificial neural networks, other methods of artificial intelligence) of the

Relationships are recorded.

The interactions identified in the previous steps

Information (e.g., predictors, rules, blurred descriptions of interactions) is fed into a database as machine-readable data. This database can comprise, in a manner known per se, one, two or more individual databases which each contain machine-readable data related to specific use cases.

Information that is determined on interacting requirements and influencing variables is optionally linked in the database in such a way that changes to one information have a direct impact on the other information (s) associated with it. The database thus generates a network of interrelated information linked to particular machine components related to a variety of different applications.

For the selection of the machine component suitable for the respective application, the influencing variables which are present in the relevant application are formulated. The application and the associated influencing variables are fed as input variables into a selection algorithm running on a computer. The selection algorithm then selects, taking account of the input variables, on the basis of the information stored in the database, which are optimally suitable for use in the respective application

Machine component off.

Essential for the invention is that in an automated process based on empirically determined or theoretically formulated and stored in a database information for the respective application optimally suitable machine element is determined accurately and that starting from the intended application. The used, in the Database stored information describe the between the respective

In the sense of a self-learning system, the quality and validity of the newly acquired information can be constantly improved in the sense of a self-learning system.

For the continuous improvement of the database created by the steps a) -f) for the selection step (step g)), the following additional steps can be completed: i) The machine component selected in step g) is filled with a

Identification means equipped, which allows an individual monitoring and detection of the machine component. j) The selected machine component is identified and monitored in its practical use on the basis of the identification means, wherein the monitoring provides information about a characteristic value representing one of the influencing variables considered. k) The statements recorded in step j) are fed as influencing variables into the process starting with step c).

For monitoring and identification of the respectively selected machine component, the identification means can not only carry information that uniquely identifies the respective machine component, but also information about the nature of the machine component

Machine component, for example, the assignment of the by the

To be able to easily assign monitoring received measured values of a particular combination of properties of the considered machine component.

The monitoring provides in the simplest case, a statement about a single characteristic value, such as over the period of time that elapses between the start of use and a wear required by replacement. In addition, however, the monitoring can also provide information about a set of two or more characteristics, such as the external influences (temperature, atmosphere) to which the

Machine component was exposed in use. The identification means may also be equipped in such a way that it provides information about the internal state and the loads of the machine element during operation. Of course, other known measuring methods can be used to the forces prevailing in the use of the machine element, its changes in length, temperature development and the like (see this example for a belt drive US 6,264,577 B1, DE 10 2010 002 551A1, JP 2009-007078 A, DE 44 44 263 C1, US 5,843,258 A, AU 2009203049 A1).

With the optional additional steps i) to k) one is optimized

self-learning, constantly improving and the practical reality always better reflecting self-learning selection system created. Of course, not every machine component selected according to the invention must pass through the supplementary work steps i) to k), but it may be sufficient if at least one machine component, optimally a representative number of

Machine components is monitored in the respective application.

For the allocation of the influencing variables to certain uses of the

Machine components can be defined as a so-called "application key", which in a standardized form coupled application and associated factors with each other. Such an application key can simplify the machine processing of the selection process.

The system according to the invention can be designed so that it is new

Applications for which there are no directly assigned information in the database, for example, based on the influencing variables assigned to this new application and the respective determined or formulated interactions from the information stored in the database, determines the closest application and based on this closest application Proposal for a machine element to be used makes. In this way, an optimally suitable machine element can be determined quickly in an iterative process, even for a new application, without the need for elaborate, time-consuming experiments.

The advantages of the procedure according to the invention thus exist in

- a detailed, application-specific consideration and dimensioning of the design according to any criteria,

optimum utilization of the product or material properties to the customer's wishes and optimum selection of the machine elements (e.g., belt or chain),

- in the specific interpretation of the specific application in relation to the particular application

Machine element and concomitantly in the avoidance of oversizing,

- in the associated optimization of the efficiency, the reduction of losses and the resulting protection of scarce resources, - in the transparency of the factors influencing each other,

- In the possibility of the respective machine element after Mafigabe a certain

Requirement to select, for example, its lifetime,

in the avoidance of uncontrolled failures, which in the state of the art can be caused by the selection of machine elements that suffice according to the previously considered selection criteria but in practice prove to be unsuitable or due to unrecognized interactions of influencing variables,

- in the continuous improvement of the forecasts more application-specific

Questions, and

- In the targeted, economic product development for specific problems, in which case the particular advantage of the procedure according to the invention is that not only individual components or groups can be considered as machine components in the selection, but that the result of the inventive

Procedure for determining the optimized for each application

Component also suggestions for the selection of certain components, materials or

May be process parameters with which a machine element or an assembly formed of several interacting machine elements ("aggregate") produced, each of which is optimally adapted to the requirements arising from the intended use.

Application-related factors can be

- Mechanical loads (speed, torque, preload forces, drive geometry, friction pairing, load changes, load cycles, speeds, accelerations, tensile or compressive stresses, other dynamic or static loads, in particular for the example "belt drive" the translation, the positioning accuracy, the balancing quality , the disc size, the number of meshing teeth, the spine deflection, the

Biegewechselfrequenz and the edge change can be important);

- environmental conditions (atmosphere in which the application takes place, ambient humidity and temperature, pollution, material pairing, pressure),

- Properties of the material that makes up the machine component (material behavior when heated, under load, under load changes, at friction, for the example "Belt drive" in particular the age of the belt as well as the characteristics of the

Production of materials used, such as corduroy, elastomers (e.g., rubber / PU, etc.), fabrics, coupling agents, and the manufacturing conditions and parameters chosen during manufacture, such as pressures, temperature, time, etc.),

- Geometric shape and quality of the machine component (these are in the example "belt drive", for example, tooth shape, gap play, shape of the discs, nature of the

Surfaces of the discs, the concentricity and the alignment of the discs,

Surface roughness, tooth shape, gap clearance, balancing quality).

In particular, the invention is concerned with the application-specific selection and design of means for transmitting kinetic energy to a component to be moved, these means being in particular belts or chains and the components directly interacting with these drive means. Which includes:

• Timing belt

• V-belt

• flat belt

• Belt drives in general, especially toothed belt drives

• slices

• Wedges

• Slices / disc profiles in total

• Transmission

• Engines

• General couplings, in particular slipping clutches

• Clamping sets / shaft-to-seam connections

• Freewheels

• Roller bearing

• Bearings

• chains

• gaskets

• Brakes

• gears

• Feathers

• Damper

• hoses

Is considered as a machine component, for example, a drive unit, which consists of the elements - "drive pulley", over which a driving force is introduced,

- "endless toothed belt" over which a load coupled with it is moved, and

"Deflection pulley", around which the toothed belt is deflected, is formed, the following factors and interactions result, for example:

Characteristic values for the loads which can play a role in the selection according to the invention and are recorded as such and stored as information in the database are, for example

- Power,

- Rotation speed,

- torque,

- preload force,

- drive geometry,

- pulley size (drive / deflection)

- number of mesh teeth,

- back deflection,

- load changes,

- load cycles,

- bending frequency,

- Flank change. The environmental conditions which can be taken into account as influencing variables in the selection according to the invention include, for example

- Chemical composition of the ambient atmosphere, such as the

Presence of ozone in the ambient atmosphere,

Temperature of the ambient atmosphere,

- humidity of the ambient atmosphere,

- Corrosivity of the ambient atmosphere - especially salinity -,

Particle pollution of the ambient atmosphere - in particular contamination as a result of metal or other abrasion -

- pressure - in particular vacuum or high overpressure -,

- temperature fluctuations.

Possible pre-damage or other mechanical imperfections of the respective machine element, in particular of the belt, may also be considered in the selection.

With the invention, it is possible to carry out a customer-oriented, simple determination of the respectively most suitable machine element, especially for individual industrial applications in small quantities.

In the following two typical embodiments of the invention will be described:

Belt drives are typically used in linear axis drives.

In the simplest case, there is a linear drive unit L1, L2, as shown in Figures 3a, 3b, of a drive pulley M, a deflection plate U, a movable carriage S and the belt R, with which the carriage S is coupled. The carriage S is moved by means of the belt R between its two end positions at the end of the axis in constant change back and forth.

In the prior art, the selection of the belt R from catalog goods usually uses the forces to be absorbed by the belt R. For both in the figures 3a, 3b outlined units L1, L2 would thus result in the same mass carriage and carriage acceleration, the same performance requirements for the respective belt R to be used. In practice, therefore, belts R are used in units L1.L2 which have identical performance characteristics. Nevertheless, they show significantly different

Lifetimes up. A common practice for the life of a belt is the so-called "mileage", ie the total distance that sweeps the belt throughout its service life. Accordingly, with the same number of load cycles, the mileage at the first linear unit L1 with its closely together drive and deflection pulleys M, U is less than in the linear unit L2, in which the drive and deflection pulleys MU are further away from each other.

In reality, such a drive will fail in one of the two end positions due to wear of the belt teeth. Only in the end positions, the belt teeth through

Acceleration and braking forces loaded. The teeth on the remainder of the travel are virtually unloaded and are overrun by the pulley, without any significant force transfer taking place here. With the same load, the service life of the teeth in the end positions is also the same, based on the number of achievable load changes. The much longer linear drive unit L2 shown in FIG. 3b, however, will achieve approximately twice the mileage in relation to the travel path with the same number of load cycles. Are the drive and deflection pulleys M, U in the linear unit L2 spaced twice as long as in the linear unit L1 and the speed at which the carriage S is moved, and the load formed by the carriage S is the same for both systems, so It can be assumed that the life of the belt R of the linear unit L2 measured in hours is significantly greater than the life of the belt R of the linear unit L1, because the mileage that has covered the belt R of the linear unit L2, twice the mileage of the belt R of the linear unit L

Another example is a so-called "omega drive (Ω drive)" Q shown in FIG.

The drive pulley M of the motor and pulleys U are mounted here on a movable carriage S. According to the current catalog value, the design of the required belt R is negligible when the friction is neglected, if the product consists of mass and

Acceleration is equal (force F = mass m x acceleration a). A very heavy slide S with low acceleration can thus lead to the same force in the belt R as a very light slide S, which experiences very large accelerations. A highly dynamic drive with high numbers of cycles is in practice but rather by Zugträgerermüdung or

Wear will fail, while a slow-moving drive that moves high masses will more likely fail due to tooth decay.

There are also environmental influences. For example, neoprene timing belts are approved for use up to 100 ° C. Neoprene softens as temperatures rise, the tooth deforms faster under load, and the belt bounces more easily. The catalog makes no difference here. Either the collateral at 20 ° C is so great that even at temperatures of 100 ° C still the values according to catalog are reached, or there is a risk at higher temperatures.

The method according to the invention provides for ascertaining the essential influencing variables on the basis of series of measurements for as many different load cases as possible in order to enable an exact belt dimensioning tailored to the respective application. The achievable mileage for drives according to Figure 3 is then determined on the basis of the achievable number of load changes over the belt length in a mileage.

An Ω drive according to FIG. 4 does not require any additional safety for operation at 100 ° C., if it is operated only in a workshop in which people work and no additional waste heat is generated. Under such conditions, the ambient temperatures reach at most 40 ° C.

For closed timing belt drives the conditions are similar. If the drive power is the same, then for example, the calculation of a drive for a fan that runs permanently in a direction of rotation, analogous to that of a drive for the

Feed axis of a machine tool, which accelerates permanently with high acceleration values from rest to rated speed and constantly changes the direction of rotation. Disk quality, gearing quality etc. are not taken into account in the calculation or, at best, via flat-rate load factors. With the method according to the invention, the overall drive can be incorporated into the belt sizing.

In the example of a fan drive, the fan always turns in one direction only. To reduce noise, the disc gap can be increased, which here has no effect on the life of the belt. The feed drive requires a small gap between belt and pulley, because high accuracy of the position are required. In addition, the constant changes of direction would always result in a sudden flank change between belt and disk toothing. Fewer gaps play results in higher friction, the risk of higher wear and lower life or, conversely, a wider belt is required to maintain the desired life to the next

Maintenance interval to achieve. So here is the achievable life in the interaction between the drive task, timing belt and pulley, under certain circumstances, even taking into account the environmental conditions dependent. standardized

Catalog specifications can not provide a solution tailored to the drive case here. Since hardly any failures are known in practice, this is proof that the drives are usually much too large to be covered by the built-in safety reserves all these unknown influencing factors. In the course of the method according to the invention, the known applications, in which, for example, the belt considered here by way of example are used, are detected. For this purpose, customer data, applications and products used, production conditions, operating conditions, etc. are recorded in detail in an application key. On suitable

Test stands will then be modeled for the application scenario typical for the respective application and, for example, life tests are carried out for this special application. The lessons learned from practical customer experience or from the test results become part of the pool of linked information stored in the database. If the customer makes the stipulation that a certain service life of the belt is desired in his application, then based on the information stored, a belt is selected which, taking into account the other conditions applicable to the intended application, is precisely dimensioned to ensure the specified service life achieved, but not beyond. That is, the customer does not receive a drive that can transmit its motor power indefinitely, but a drive that performs the drive task for the customer's, e.g. desired life or other criteria desired by the customer such.

Environmental influences, costs, etc. reliably fulfilled. Spare parts requirements (and thus the

Spare parts business) become calculable and can be adapted to the maintenance and service intervals accordingly.

A belt drive and a method that allow to determine the loads to which the essential components "pulley" and "belt" are subjected in a belt drive are the subject of German patent application 10 2015 107 177.0 entitled "Belt drive and method for monitoring Such a belt drive "filed by the Applicant of the present application on the same day as the present application at the German Patent and Trademark Office and the content of which is incorporated in the disclosure of the present application.

The success of the selection according to the invention becomes clear from the following example:

An application in which the diameter small drive and deflection pulleys are operated at high speed and in which a small center distance and a concomitant high bending frequency of the tension members are combined, results in conventional approach to the result that this requirement collective not with a standard belt can be fulfilled.

It should be determined a belt for an application in which a

Requirement collective revealed, for the according to conventional procedure no suitable, as a catalog product prefabricated belt - no special order - could be determined. Taking into account the further influencing variable "heating of the belt as a result of the heating, which results from the flexing work required in the belt circulation", however, a belt could be determined in the manner according to the invention, which at a reduced speed

Back thickness of a thinner and more flexible tension member and a softer

Compound of rubber exists. Here, in the selection made according to the invention, experience also plays an essential role in that the thinner tension member better tolerates the bending load and that as a result of the softer rubber compound, the lower one

Belt thickness and the flexible tension member lower flexing work to a lesser

Warming of the belt in use leads.

The selection, which takes place according to the invention with the inclusion of new factors and practical experience and possibly experimentally confirmed interactions, thus gave a timing belt that meets the demands placed on his life expectancy, although not found in conventional approach or due the safety premisses provided by the conventional procedure would have been sorted out of the circle of belts in question. Insights gained in the practical use of the appropriately selected belts are included in the inventively constructed database for refinement of the selection criteria, so that in the next search for a belt which is intended for an application subject to the same requirements, a still better fitting toothed belt is found purposefully.

To detect its function and the load applied to the timing belt selected in the above-described manner in practical use, individual ones of these belts can be systematically monitored on a test rig which depicts the real-world requirements and conditions. The same could be implemented with the machines equipped with the toothed belts selected according to the invention.

Both on the test bench and in the respective appropriately equipped machines then belts are used, in which an identification means has been attached in the course of their manufacture or packaging. This identification means may be an RFID chip which is inserted into the material of the belt. The RFID chip may carry information about the belt and be equipped to transmit this information to a sensor located at a suitable location on the test stand or machine and detecting the respective information. Likewise, at least one of the disks of the drive, which is assigned to the belt selected according to the invention, with be equipped with an identification means. Its information can also be detected by a sensor.

The acquired information is then transmitted to an evaluation unit. By adjusting the information supplied by the belt and the disc new information about the synchronous operation, the duration of use, the wear, the concentricity, etc. of the drive can be obtained, which are used to improve the validity of the information contained in the inventively constructed database.

Of course, other identification means than the RFID chips mentioned here for the identification of the belt and the disc can be used. It would be conceivable, for example, to design the identification means such that they actively detect, for example, the temperature development, deformation or dynamic forces to which the belt is exposed during use and supply it to the sensor. Such actively obtained data in turn contribute to the improvement of the result of a selection made according to the invention.

In the following examples are presented where in practice with the

The procedure according to the invention succeeds in determining optimally suitable machine components for the respective use.

Practical example 1:

Beverage bottling plants contain numerous rotary drives, which are often designed as belt drives.

In the bottling operation, it happens again and again that a bottled drink is spilled and the moving parts of the belt drives are wetted with the drink.

At the same time, beverage bottling plants are subject to strict hygiene regulations and must be cleaned regularly. For this purpose, comparably aggressive cleaning chemicals are used.

Due to the frequent cleaning processes and the arrangement of the drives, usually below the plants, the belt drives are difficult to access. This often causes the cleaning chemicals to adhere to them and dry.

Assuming that the drink to be filled has no significant effect on the service life of the respective drive belt, in the procedure according to the invention, the influencing variables which are essential for the use of a "beverage filling machine" are first to be transmitted forces and the chemical pollution has been taken into account by the cleaning chemicals in interaction with the material to be regarded as "property" within the meaning of the invention, of which the components "drive belt" and "pulley" of the belt drive.

In practical use of the drive belt designed in this way, it was found that in the filling of certain drinks despite the presupposed resistance to the

Cleaning chemicals came to a massive early damage to the drive belt, whereas the belt when filling other drinks easily provided

Lifespan reached.

A comparison of the respectively inventively recorded operating conditions under which the belt in question were used, found that as a further influencing factor for the

Use case "Beverage bottling plant" the type of beverage to be bottled and its

Interaction with the cleaning chemical or the material used in the belt drive machine components "drive belt" and "pulleys" must be considered.

By recognizing the information about this additional interaction in the

The selection process according to the invention has been included as a result of

Bottling lines, in which high-sugar drinks are bottled, belts made of a combination of materials have been proposed that are insensitive to that

spilled sugar beverage stains, water and cleaning chemicals forming, certain belt materials aggressively attacking liquid mixture are, whereas in beverage plants, in which drinks are filled with lower sugar levels, conventionally designed drive belts can be used.

Practical example 2:

Polyurethane timing belts ("PU belts") are generally very resistant to water and moisture. In dry air, temperatures up to +50 ° C, sometimes even +80 ° C are no problem for the PU belts. Similarly, it is not a problem when operating PU belts at high humidity and room temperature.

However, if a high humidity and a high temperature in combination, this will destroy the PU material of the belt.

An essential characteristic of the process according to the invention for selecting a suitable belt for the use of "drive of an aggregate" is therefore also the basic material of which the respective belt is made, as well as "influencing variables" which are in use in each case expected ambient temperature and humidity, and as "interaction", the effects on the material of the belt depending on the absolute value of the temperature and humidity.

Practical example 3:

When using "drive a machine tool" as a "property" are the material of the available drive belts and as influencing factors for the selection process in addition to the expected mechanical stresses, the temperature conditions and coming in the machine tool used lubricants and their interaction with the respective material considered, from which the belts consist.

Practical example 4:

For cleaning purposes, so-called deionized water is frequently used, from which all minerals have been extracted. Are timing belts, seals and others

Machine components are used in a correspondingly polluted environment, as "property" in the selection according to the invention, in turn, the materials of the machine components and considered as "interaction" their interaction with the demineralized water.

The information which is crucial for the selection according to the invention and is included in the database provided according to the invention as a rule for the interactions of the influencing variables involved is that, if the material of the machine components contains a plasticizer, there is a high tendency for the material to migrate as a result of the osmotic gradient Water wanders. For example, drive belts whose base material is an elastomer tend to be prematurely embrittled when used in an environment where deionized water is used.

Practical example 5:

It is known that moldings made of polyamide under certain

Environmental conditions tend to absorb water and that with the water absorption, a change in the dimensions of the molded part may go hand in hand.

If molded parts made of polyamide are to be used in drives in which close fits of the interacting machine elements are required, changing environmental conditions can consequently lead to problems.

This information about the "interaction" of the "property" material = polyamide with the "Influencing variables" temperature and ambient humidity is in the invention

provided database.

Based on the requirement that the respective machine component is made of polyamide and a maximum dimensional stability is to be ensured, the selection according to the invention results in the statement that the respective molded part is in a constant environment

Temperature and humidity to operate.

Practical example 6:

Another example of that as influencing factors for the selection of the respective

Drive means, the environmental conditions can be of crucial importance, are theater lights in which are used to focus the light beam adjustable aperture. The adjustment takes place via electric motors, with the aperture over

Timing belts are coupled.

By using in the selection according to the invention as essential information

Interaction between the high temperature, UV and ozone load prevailing in the vicinity of the luminaire on the one hand and the base material ("property") of the toothed belt on the other hand, the method according to the invention for the use of "theatrical luminaire" yields a drive belt, which, despite the adverse conditions, does not tend to embrittle, as occurs under these conditions in belts whose

Base material is a conventional elastomer.

Practical example 7:

In certain applications, a particularly quiet, noise-minimized run of a respective belt drive is desired.

"Noise emission" is thus the result of the interaction of certain properties and influencing factors, which are also to be considered when selecting the suitable machine component in relation to the respective application.

Through appropriate experiments, a qualification of certain fabrics ("property") for a reduced noise can be performed, with additional certain material pairings ("interaction of properties"), certain operating conditions ("influencing variables") and certain geometries ("properties") of the interacting machine elements be systematically investigated to describe the interactions between the different materials in terms of noise. The information obtained by these experiments is provided in the invention Database stored and coupled with the existing information there for the respective use case.

Practical example 8:

The choice of tension members (e.g., aramid, carbon fiber) may in some instances determine whether or not a belt is suitable for deflection over the belt spine, or to what radii of curvature that may be. With increasing service life, small cracks occur during the deflection over the belt back due to the alternating bending in the very hard polyurethane, which increase with increasing number of bending cycles.

Aramid tensile carriers are very sensitive to notch effect. While this influence now leads to fractures in the aramid tension member, the carbon tension member tolerates this influence because the notch sensitivity is lower.

The effect is the stronger, the smaller the bending radii and the higher the speed. This means that at low speed and correspondingly large deflection also the Aramidzugträger with back deflection can lead to sufficient life. With the

According to the invention, a characteristic value can be determined from these relationships, up to which the aramid tension member would also be usable in the case of back flexing. In addition, there are influences on the Zugträger by external influences, such as

For example, moisture (creep of the tensile carrier in moisture).

Another influence that enhances the effect is the peculiarity of aramid, to shorten under heat in the longitudinal direction of the fibers. When the belt becomes warm, it contracts or, if it is prevented from contracting by the pulleys, the belt tension increases. Again, this affects the effects of cracks on the

Notch sensitivity of the tension member. Accordingly, these features are also taken into account in the selection system according to the invention as influencing variables (power, speed or rotational speed, ambient humidity, back deflection and their diameter, temperature) and interactions which influence the design criterion "service life of the belt in the specific application"

Practical example 9:

For drive belts used in automobiles, the type of winding of the tension members affects the service life of special applications. This not only has the choice of

Zugträgermaterials, but already the individual structure of a single pull cord influence on the life of the drive belt. Thus, belts with a higher number of tensile member strands have very good dynamic

Bending properties on, while belts with a smaller number of

Zugträgersträngen in a dynamic engine application with the occurring there start-stop changes, temperature influences and numerous bending changes to premature

Failures lead. By pure static tensile or elongation tests, the differences are not detectable, but can be systematically recorded only by empirical detection of suitably equipped in accordance with the invention belt in the field trial.

The results of such systematic experiments are called properties or

Influencing variables are fed into the database system provided according to the invention and, together with the description of the interactions of these properties and influencing variables also stored in the database, form the criteria for the selection of the reference to the

Application of the most suitable component.

Practical example 10:

According to the manufacturer's specifications, certain timing belts are approved for use in certain temperature ranges. It remains, however, under what other

Conditions the belts may be used in these temperature ranges.

Practice shows that it makes a difference whether a belt is operated at a speed of 5000 rpm at ambient temperatures of 20 ° C in a well-ventilated environment, or whether the belt is exposed to an ambient temperature of 60 ° C in a small closed gearbox , The belt operated at the high temperature in a narrow space will not achieve a satisfactory life even if the manufacturer's specifications are met.

Only when environmental conditions are taken into account in the selection of the suitable belt according to the invention can a drive belt which reliably functions even at high temperatures and narrow spatial conditions be determined.

REFERENCE NUMBERS

L1, L2 linear drive units

M drive pulley

R belt

S sled

U deflection pulley

Q Omega drive (Fig. 4)

Claims

P A T E N T A N S P R E C H E

1. A method for computer-assisted selection of a machine component intended for a particular use, comprising the following steps: a) Properties of the particular machine component under consideration and influencing variables determining these properties are determined. b) Possible applications are determined for the particular machine component considered. c) For the respectively considered machine component, those at the

A method according to claim 1, characterized in that in the case that it turns out in step d) that unidentified influencing variables exist, these newly recognized influencing variables become the group of

considering and interacting with other influential factors.

Method according to one of the preceding claims, characterized

in that the database to which the previously determined information is fed in step e) comprises one, two or more individual databases, each of which contains machine-readable data related to specific use cases.

Method according to one of the preceding claims, dadurc

characterized in that in the database, in the step e) the previously determined information is fed, the information that is determined to interacting requirements and influencing factors, linked together so that changes to the one information directly affect their have linked other information (s).

Method according to one of the preceding claims, characterized

characterized in that the ongoing improvement of the

Steps a) - f) for the selection step (step g)) created additional data base, the following steps are completed: i) The selected in step g) machine component with a

Identification means equipped, which allows an individual monitoring and detection of the machine component. j) The selected machine component is identified and monitored in its practical use on the basis of the identification means, wherein the monitoring is a statement about one of the influencing variables considered

Characteristic value. k) The statements recorded in step j) are fed as influencing variables into the process starting with step c).

6. The method according to claim 5, characterized in that the

Identification means in addition to information that uniquely identifies the respective machine component, contains information about the nature of the machine component.

7. The method according to claim 5 or 6, characterized in that in the step j) the time period is detected, which elapses between the beginning of use and a wear required by replacement.

8. The method according to any one of claims 5 to 7, characterized in that the monitoring in step j) provides statements about a set of two or more characteristics.

9. The method according to any one of claims 5 to 8, characterized in that the identification means is equipped such that it provides information about the internal state and the loads of the machine element in operation.