IMPROVED OPERATING PROCEDURE FOR GEARBOXES

Description

[0001] The invention relates to an operating method for a transmission, with which a probable failure time for a transmission component can be predicted. The invention also relates to a computer program product with which the claimed operating method can be implemented. Likewise, the invention relates to a control unit for a transmission equipped with a corresponding computer program product. The invention also relates to a monitoring system having such a control unit. Furthermore, the invention relates to a transmission that can be coupled to such a monitoring system and to a transmission application equipped with a corresponding transmission.

[0002] US 2012 / 0029838 A1 discloses a gearbox for a wind turbine equipped with a plurality of acceleration sensors and speed sensors. These generate measurement data that represent the vibration state and speed of at least one shaft. The acceleration sensors and speed sensors are connected to a control unit, which is evaluated by a computer program. Based on this data, the computer program determines the existing damage status of the gearbox.

[0003] US Pat. No. 7,606,673 B2 discloses a method for analyzing bearing vibrations. A degradation factor is determined and combined with a mean time to failure (MTTF). From this, a reduced mean time to failure (RMTTF) is calculated. The degradation factor, in turn, is determined using discriminants from a frequency analysis. A failure probability for the bearing is then determined based on the RMTTF. Furthermore, the method in US Pat. No. 7,606,673 B2 determines the impending financial consequences of a bearing failure and the current repair costs, and displays these to the user.

[0004] Document DE 10 2007 017 614 A1 discloses an operating method for transmissions in which damage accumulation is determined for rotating components of the transmission. Furthermore, a load spectrum is determined. A component to be analyzed is divided into several sections, and individual load spectrums are determined accordingly.

[0005] EP 2 264 314 A2 discloses an operating method for a wind turbine in which operating states of the wind turbine are classified. The electrical power generated by the wind turbine depends on the wind strength, with increased wind strength also leading to increased stresses, particularly increased vibration loads. The vibration loads are divided into five categories. An expected service life is calculated for each stress in one of these five categories.

[0006] US 2004 / 260512 A1 discloses a method for damage assessment in which a damage mechanism is modeled. Different loads are considered at their respective intensity intervals, which are summed to produce a damage. For further precision, different temperature levels can be considered.

[0007] From US 7 149 657 B2 it is known to bundle data from a variety of sources that have an influence on the aging of a component and to use this to estimate a remaining service life.

[0008] From US 5 210 704 A it is known to test a helicopter gearbox until mechanical failure and to determine various possible damage mechanisms in the serviced helicopter gearbox with the help of the data obtained in this way and data measured during regular operation of an identical helicopter gearbox of a helicopter during maintenance on the ground.

[0009] When operating transmission applications, especially in wind turbines or industrial applications, there is a desire for increasingly precise predictions of impending failures of transmission components and the associated impact assessment. A disadvantage of existing methods for predicting component failure is that their prediction accuracy falls short of the ever-increasing requirements. There is a need for a method for predicting the impending failure of a transmission component in a transmission that can be implemented simply and cost-effectively.

[0010] The problem is solved by the features of the independent claims.

[0011] The operating method is used to operate a transmission that comprises a plurality of transmission components. A transmission component includes, for example, spur gears, bevel gears, planetary gears, planet carriers, ring gears, sun gears, their associated shafts or axles, seals, plain and rolling bearings, torque arms, screws, shaft-hub connections, keyways, short gears, or housing components. In the method according to the invention, an operating state of the transmission is brought about in a first step. An operating state is a state of the transmission in which, in particular, a mechanical state of the transmission can be described using sensor data. This can be a steady-state operating state, but also a transient process, such as an acceleration phase. During the operating state, a mechanical stress on a first transmission component is detected.The mechanical stress corresponds to the current operating condition. Such a mechanical stress on a first gear component can be, for example, a torsional stress on a sun shaft, a radial force acting on a plain bearing, or a rotational speed of a planetary gear. The mechanical stress can be determined directly, as in the case of the rotational speed of a planetary gear, or indirectly derived from directly recorded measurement data using a physical model. This can, for example, be a torsional stress on a sun shaft, which is determined via a strain gauge on its surface. In a second step, a damage contribution for a first damage mechanism is determined based on the determined mechanical stress.A rising and falling mechanical stress on the first transmission component can be recorded and evaluated, for example, as a service-life-consuming stress, i.e., as a damage contribution, within the context of so-called low-cycle fatigue (LCF for short) or so-called high-cycle fatigue. Alternatively or additionally, the first damage mechanism can also be wear, tooth breakage, or pitting on a gearing. According to the invention, the damage contribution is determined for at least the first damage mechanism. The first damage mechanism, i.e., the type of damage process, is adjustable; the setting can be made via an algorithm, a table, or user input.

[0012] In a third step, the damage contribution is added to a damage sum in a first damage accumulation model of the first damage mechanism. Such damage accumulation models exist for a variety of damage mechanisms, such as the linear damage accumulation according to Palmgren and Miner. The addition is to be understood as adding in the sense of the corresponding damage accumulation model, so that in the third step, the progress of the first damage mechanism is determined using the damage sum. A fourth step follows based on the existing damage sum. In the fourth step, a model remaining service life of the first transmission component is determined using the first damage accumulation model. The model remaining service life is based on an existing theoretical description of the first damage model.This takes into account a predicted damage amount at which failure of the first transmission component is theoretically expected. Based on the theoretical model of the first damage mechanism, which is used to determine the model remaining service life, a probability of occurrence for the first transmission component reaching the model remaining service life is also determined. The probability of occurrence describes, for example, the probability with which the first transmission component will reach the predicted model remaining service life.

[0013] According to the invention, the probability of occurrence for the model's remaining service life is determined based on data sets collected from comparison components. The comparison components are essentially identical in design to the first transmission component. To collect the data sets, the comparison components were or are subjected to stresses, and the damage behavior, in particular the failure of the corresponding comparison component, is recorded. Based on the majority of comparison components and the corresponding data sets, a maximum damage sum—i.e., the tolerable damage until failure—of the comparison components and the first transmission component can be determined through statistical evaluation.This, in turn, allows a statement to be made about the probability of the maximum damage amount that is actually tolerable for the first transmission component and thus about the probability of the model remaining service life being achievable by the first transmission component. The method according to the invention thus makes it possible to transfer experience gained from identical comparison components to the first transmission component used. The determined model remaining service life and / or the corresponding probability of occurrence can be displayed to a user for monitoring the operation of the transmission, for example, on a screen or display. During the operation of long-life transmission applications, such as wind turbines or industrial applications, this increases the accuracy of predicting the failure of transmission components.The longer the stressed operating process runs, the more precise its predictions become due to the growing experience with comparable components. Given that transmission applications generally become increasingly susceptible to repairs with increasing age, the method according to the invention makes maintenance of transmission applications more predictable and thus more economical. This extends the overall economically viable service life of transmissions.

[0014] In the claimed operating method, a fifth step can also be carried out in which a warning is issued if the model remaining service life falls below an adjustable first threshold and / or the probability of occurrence falls below an adjustable second threshold. Falling below the first threshold can thus warn of an anticipated short-term failure of the transmission component. Falling below the second threshold indicates that reaching an adjustable desired remaining service life is now sufficiently unlikely. By combining the first and second thresholds, a user can set a warning profile that allows advantageous operation of the transmission by avoiding unforeseen failures. This enables even more reliable and economical operation of the transmission overall.

[0015] Furthermore, the comparison components, based on whose data sets the probability of occurrence for the model's remaining service life is determined, can be used at least partially outside the transmission. The comparison components are thus used in third-party transmissions belonging to a different transmission application. A third-party transmission is understood to mean any transmission that is not the transmission itself described here. The transmission application in which the transmission operated with the claimed method is used is a different transmission application. For example, for rolling bearings, shafts, or housing components, data sets from corresponding transmission components used in vehicle transmissions can be used. Due to the high volumes in automotive technology, a large number of data sets can be easily provided, allowing a reliable assessment of the corresponding damage mechanism.Alternatively or additionally, data sets of comparison components can be obtained through measurements in a test field in which a corresponding reference machine is operated. The data sets of the comparison components are made available for retrieval in a memory for the claimed method, for example, via a data connection. The operating method is thus capable of utilizing an increased number of comparison components on the basis of which the probability of occurrence for the model's remaining service life is determined. The more comparison components are available, the faster the assessment basis for the probability of occurrence grows, which in turn allows a more precise determination of the probability of occurrence. In particular, rarely occurring damage events can be included in the determination of the probability of occurrence, which also increases the accuracy of determining the probability of occurrence.

[0016] In the claimed operating method, a mechanical stress on a second transmission component can also be determined in the second step based on the mechanical stress on the first transmission component in combination with a transfer function. The transfer function is designed in such a way that a physical relationship is established between the first and second transmission components. For example, a static deflection of the planetary gear axle can be determined based on a radial load on a rolling bearing on a planetary gear axle. Likewise, a transfer function can be obtained from a finite element model of at least one housing component.

[0017] Furthermore, a bearing reaction can be determined by cutting free a shaft subjected to a torsional moment. Such a physical relationship can preferably be mapped in a digital twin of at least one component of the transmission or of the entire transmission. Based on the mechanical stress on the second transmission component, at least the third and fourth steps are carried out, thus determining a model remaining service life and an associated probability of occurrence for the second transmission component. Corresponding determinations are made based on data sets from comparison components that are essentially identical to the second transmission component. The claimed method is thus suitable for using existing measurement data and further evaluating it. Equipping additional transmission components with sensors is therefore unnecessary.This increases the functionality of the required operating procedure in a simple and cost-effective manner.

[0018] Furthermore, in the second step, a damage contribution for a second damage mechanism can be determined based on the mechanical stress on the first transmission component during the claimed operating process. The third and fourth steps are also carried out based on the damage contribution; i.e., a damage sum, a model remaining service life, and a corresponding probability of occurrence for a second damage mechanism acting on the first transmission component are determined. By monitoring and evaluating multiple damage mechanisms, a more flexible prediction of failure of the first transmission component is possible. For example, in the case of pulsating stresses on the first transmission component at different frequencies, high-cycle fatigue and low-cycle fatigue can be monitored simultaneously. Furthermore, wear, tooth root fracture, or pitting on a gearing can be monitored as damage mechanisms.The resulting versatility of the claimed operating method further increases its prediction accuracy. Furthermore, in a subsequent step, the damage mechanism under which the first and / or second transmission component fails can be determined. This makes it possible to verify whether the first and / or second damage mechanism is correctly selected for the respective transmission component. Corresponding data can be provided as a dataset, allowing the existing empirical base for the corresponding transmission component to be automatically expanded. This further increases the accuracy of damage prediction.

[0019] In a further embodiment of the claimed operating method, the probability of occurrence for the model's remaining service life is determined using a distribution function of permissible damage sums for the reference components. The permissible damage sums are the aggregated damage contributions at which a failure of the corresponding reference component has occurred. Using the distribution function, it is possible to determine which permissible damage sum, i.e., maximum damage sum, can be expected for the first transmission component and with what probability. For example, this includes a Wöhler curve for a reference component, which is unique to the respective reference component and relates to a specific damage mechanism.The data sets of the comparison components used to determine the probability of occurrence of the model's remaining service life can include the respective Wöhler curves and / or permissible damage sums, i.e., maximum damage sums. According to the invention, the data sets also contain information about the type of the corresponding damage mechanism, in particular information about a dominant damage mechanism. A dominant damage mechanism is understood to be the damage mechanism that is likely to lead to the failure of the transmission component and is therefore dimensioning the transmission component. In addition, the specification of a dominant damage mechanism can be stored in the data set specifically for different applications. This allows the expected failure horizon of the transmission component to be described more precisely.

[0020] Furthermore, in the claimed operating method, the existing damage sum can be designed to be changeable during the course of the method. The damage sum can thus be corrected during operation, for example to account for damage events that are not represented by measurement data on the first or one of the other transmission components. Likewise, service life-extending measures can be taken into account by making a corresponding change. This could be, for example, changing the transmission oil or replacing a transmission component. The change in the damage sum can be made, for example, by an algorithm that can record maintenance processes. Alternatively or additionally, the damage sum can also be changed by user input. Consequently, the claimed operating method is suitable for more comprehensively mapping the current operation of the transmission and thus increasing its forecasting accuracy.

[0021] In the claimed operating method, in a further step, the expected repair effort can be determined based on the model remaining service life of the first transmission component and / or its probability of occurrence for the first transmission component and / or the transmission. The repair effort can be determined, for example, by accessing an experience database in which data on labor requirements, tool requirements, procurement time for a spare part, and / or spare part costs for replacing the first transmission component are stored. Alternatively or additionally, the expected consequential failure costs that can be expected in the event of a failure of the first transmission component are determined. This includes, in particular, downtimes of the transmission and / or the associated transmission application. This allows a user to plan a targeted maintenance process for the transmission or transmission component.

[0022] In a further embodiment of the claimed operating method, a stocking instruction can be issued for the first transmission component if the model's remaining service life falls below the adjustable first threshold and / or the probability of occurrence falls below an adjustable second threshold. The stocking instruction can be embodied as a message or command to materials management software, so that the stocking instruction initiates the procurement of a spare part for the first transmission component. Alternatively or additionally, in addition to the first and / or second threshold, further data can also be taken into account, such as a procurement period or available capacity of maintenance personnel. In particular, falling below the first and / or second threshold can be linked to the stocking instruction.This allows more precise monitoring of the operation of the corresponding transmission including its corresponding transmission components.

[0023] Furthermore, the claimed operating method can determine the model's remaining service life and / or its probability of occurrence based on an adjustable load level for continued operation. The load level characterizes the expected mechanical stresses on the first transmission component. The adjustable load level can be designed as an extrapolation of a load level existing during previous operation. Alternatively, the adjustable load level can also correspond to a planned operating mode of the transmission. Further alternatively, the adjustable load level can be designed as a section-by-section combination of a previously existing load level and a load level that corresponds to the planned operating mode. The load level for continued operation can be set using an algorithm, a table, and / or user input.In an industrial application, an algorithm for adjusting the load level for continued operation can, for example, be coupled with work scheduling software. In a wind turbine, such an algorithm can, for example, be designed as a forecast based on a weather database.

[0024] According to the invention, at least one model remaining service life and its probability of occurrence are stored in a data set containing information about the type of the corresponding damage mechanism. Furthermore, in the claimed operating method, at least one mechanical stress, at least one damage contribution, at least one damage amount, and / or at least one type of information about a first damage mechanism can be stored in the data set. The data set can be stored, for example, in a memory located outside the transmission or the transmission application. The data set stored in this way can be further modified by a user. Furthermore, the data set stored in this way is provided as a comparison data set for other essentially identical transmission components. The first transmission component monitored using the claimed operating method thus serves as a comparison component for other transmission components.Through the interaction of a large number of identical transmission components, an empirical database can be created that allows a precise forecast for the corresponding transmission components for a wide variety of applications. Furthermore, a so-called big data analysis can be carried out on a large number of correspondingly provided data sets of identical transmission components, which can be used to identify systematically occurring damage. This could, for example, be the premature failure of a specific bearing. Such a big data analysis makes it possible, in particular, to improve existing designs and thus to maintain an existing model range of transmissions in a targeted manner. Furthermore, data sets of comparable components can serve as input for a machine learning algorithm, and the machine learning algorithm can identify damage patterns that could, for example, lead to premature failure.This will allow further benefits to be derived from the data sets generated by the claimed method.

[0025] The underlying problem is also solved by the computer program product according to the invention. The computer program product can be stored in non-volatile form on a data storage medium, such as a hard disk, a USB memory, or an optical data storage medium, and can be executed with a corresponding computing unit. The computer program product according to the invention is designed to implement an operating method according to at least one of the embodiments outlined above for operating a transmission. For this purpose, the computer program product according to the invention comprises at least one first subprogram. The at least one first subprogram is designed to implement the claimed operating method either completely or partially. In a partial implementation of the operating method, the first subprogram is at least temporarily communicatively linked to a second subprogram.A communicative connection between the subprograms is understood to mean a coupling involving one-way or mutual data exchange, for example, an internet connection. This allows different functions of the underlying method to be implemented with the first or second subprogram. For example, a threshold value or a damage amount can be set via the second subprogram, while the comparison with these threshold values ​​or damage amounts is performed in the first subprogram. The solution according to the invention is thus modular and can therefore be implemented in a simple form.

[0026] The underlying problem is also solved by the control unit for a transmission according to the invention. The control unit has a memory and a computing unit designed to execute a computer program product. Furthermore, the control unit can be connected directly or indirectly to a plurality of sensors by which the first transmission component can be monitored. The control unit is also designed to receive and evaluate associated measurement data from the sensors. According to the invention, the control unit is equipped with a computer program product according to one of the embodiments presented above and is thus suitable for implementing the operating method according to the invention.

[0027] Furthermore, the claimed control unit for a transmission can be designed as an internal control unit or as a higher-level control unit. An internal control unit is attached to the transmission or to its associated transmission application. This can be mounted in or on a housing of the transmission, or on a machine frame to which the transmission is attached. A higher-level control unit, in turn, can be installed separately from the associated transmission at a different location. For example, the higher-level control unit can be designed as a programmable logic controller (PLC for short), as a host computer, as a web server, or as a computer cloud. Likewise, at least one internal and one higher-level control unit can be provided to implement the operating method according to the invention. The internal and higher-level control units are designed to have at least a temporary communicative connection with one another.

[0028] The underlying problem is also solved by the monitoring system according to the invention, which is designed to monitor at least a first transmission component. The monitoring system comprises a plurality of sensors, each of which is designed to record measurement data. The measurement data that can be determined by means of the sensors correspond to at least one mechanical stress to which the first transmission component is subjected during operation of the transmission. This can be, for example, a rotational speed and a radial stress of a rolling bearing. The monitoring system also comprises at least one control unit that is connected to the plurality of sensors and is designed to receive and evaluate their measurement data. The at least one control unit is designed as an internal control unit or as a higher-level control unit in the sense of one of the embodiments outlined above.Alternatively, the monitoring system can also comprise an internal and a higher-level control unit that are at least temporarily communicatively connected to each other. Optionally, the monitoring system can also be equipped with a pattern memory in which a plurality of reference states are stored, which can be used for further evaluation of a given operating state.

[0029] Furthermore, the object is achieved by the transmission according to the invention. The transmission comprises a plurality of transmission components and is designed as a planetary gear, spur gear, or bevel gear. The transmission comprises at least a first transmission component and is coupled to at least one sensor, wherein the sensor is assigned to a monitoring system. The monitoring system is designed according to one of the embodiments described above. The transmission according to the invention can thus be monitored using the operating method described above, and impending damage to the first transmission component can thus be reliably predicted.

[0030] The underlying problem is solved equally by the transmission application according to the invention, which comprises a drive unit and an output unit. A transmission is arranged between the drive unit and the output unit to transmit torque and is designed to change the speed from the drive unit to the output unit. The drive unit can be designed, for example, as a wind turbine rotor, as an electric motor, as an internal combustion engine, or as a hydraulic motor. The output unit can be designed as a generator or as a mechanical application, such as a tube mill, a cement mill, a vertical mill, as an extruder, as a conveyor belt, as a pump, as a compressor, as a lifting system, or as a scrap or waste press. Alternatively, the output unit can also be designed as the shaft of a vehicle drive.Accordingly, the transmission application can be configured as a wind turbine, an industrial application, a land vehicle, a watercraft, or an aircraft. An industrial application can be configured as a mill, vertical mill, sugar mill, cement mill, rock crusher, conveyor belt, pump, roller press, apron conveyor, tube mill, rotary kiln, rotating gear, agitator, lifting device, waste compactor, or scrap press. According to the invention, the transmission is configured according to one of the embodiments outlined above. By using the operating method according to the invention, more reliable operation of the transmission is achieved, thus increasing the reliability of the transmission applications.

[0031] The invention is described below using individual embodiments. The features of the individual embodiments can be combined with one another. The figures are to be read as complementary to one another, in that identical reference numerals in the figures also have the same technical meanings. They show in detail: FIG 1 shows a schematic structure of a first embodiment of the claimed transmission; FIG 2 shows a schematic sequence of a first embodiment of the claimed method; FIG 3 shows a diagram of a step of the claimed method; FIG 4 shows a schematic sequence of a second embodiment of the claimed method; FIG 5 shows a schematic sequence of a third embodiment of the claimed method; FIG 6 shows a schematic structure of a claimed monitoring system; FIG 7 shows a schematic structure of a claimed Ge drive application.

[0032] FIG 1 shows schematically a structure of a first embodiment of a claimed transmission 10, which has sensors 22 and a control unit 40 designed as an internal control unit 42, with which the claimed method 100 is implemented. The transmission 10 comprises a housing 11, in or on which a plurality of transmission components 12 are accommodated. The transmission components 12 are designed as gears 14, as shafts 16 and as bearings 18. The transmission 10 is, without limiting the generality of the invention, in FIG 1 designed as a spur gear. The gears 14 are mounted on the shafts 16, which in turn are rotatably received in bearings 18. The bearings 18 are fastened to the housing 11. Each of the gear components 12, i.e. each gear 14, each shaft 16 and each bearing 18, is provided with a sensor 22 which is suitable for directly or indirectly detecting a mechanical stress 25 of the corresponding gear component 12 during operation of the gear 10. For this purpose, the sensors 22 are designed as strain gauges (DMS for short), as force transducers, as temperature sensors, speed sensors, surface acoustic wave sensors (SAW sensors for short), as cameras, or a combination of these. Direct detection of a mechanical stress 25 is understood to mean, for example, detecting a strain on a surface of a shaft 16 using a DMS or an SAW sensor.Indirect detection of a mechanical stress 25 is understood, for example, as a temperature detection of a bearing 18, wherein a thermal expansion state of the bearing can be determined from the detected temperature using a corresponding model. The sensors 22 are designed to generate measurement data 27 accordingly, which is transmitted to a control unit 40. When the mechanical stress 25 of a transmission component 12 is indirectly detected, the mechanical stress 25 can be determined by at least one of the control units 40 from the received measurement data 27.

[0033] The internal control unit 42 is connected to a further control unit 40, which is designed as a higher-level control unit 44. The control units 40 are communicatively coupled to one another via a data connection 45. A computer program product 80 is stored in non-volatile form on both control units 40 and is also executed during operation of the transmission 10. The computer program products 80 are suitable for processing the received measurement data 27 and are designed to implement the method 100 according to the invention using the measurement data 27 on the transmission 10. The data connection 45 also allows parameters 73, which influence the sequence of the method 100, to be exchanged between the internal control unit 42 and the higher-level control unit 44.The parameters 73 used in the internal control unit 42 for the execution of the method 100 can thus be set in terms of type and value by the higher-level control unit 44 as a specification 77. Likewise, specifications 77 for the method 100 can be exchanged between the higher-level control unit 44 and the internal control unit 42, which are specified by an algorithm 79. Such an algorithm 79 can be executed on the internal control unit 42 and the higher-level control unit 44. The specifications 77 can also be generated by a user input 78, which is made at the higher-level control unit 44. The higher-level control unit 44 is also communicatively coupled to a database 60 via a data connection 45. Data records 64 of comparison components 62 are stored in the database 60 and can also be forwarded to the internal control unit 42 as parameters 73.The data records 64 of the comparison components 62 are used as comparison values ​​for carrying out the method 100 according to the invention. These are comparison components 62 that are essentially identical in construction to the corresponding transmission component 12 to be monitored by the method 100. Furthermore, the higher-level control unit 44 is communicatively connected to a materials management system 68 via a data connection 45. The higher-level control unit 44 is designed to output a stocking instruction 66 to the materials management system 68 in order, for example, to reserve or procure a corresponding spare part in the event of an impending failure of a transmission component 12. Likewise, the higher-level control unit 44 is suitable for outputting a warning 65 to a user if the method 100 determines that a failure of a transmission component 12 is imminent.

[0034] In FIG 1 the transmission 10 is shown in an operating state 20 in which a first method step 110 is carried out. Drive power 21 is supplied, which, taking mechanical losses into account, is output again as output power 23 from the transmission 10. The drive power 21 creates the mechanical stresses 25 in the transmission components 12, which are detected by the sensors 22. The operating state 20, from which the method 100 starts in the first method step 110, is to be understood as an operating state in which the sensors 22 generate usable measurement data 27 within the meaning of the method 100. The operating state 20 can be a stationary operating state or a transient process, for example an acceleration.

[0035] In FIG 2 is schematically shown a further sequence of an embodiment of the claimed method 100, which is carried out on a transmission component 12 as in FIG 1 is carried out. The transmission component 12 is a shaft 18 which is coupled to a sensor 22. The transmission component 12, i.e. the shaft 18, is subjected to a torsional load 26 during an operating state 20 present in a first method step 110. The torsional load 26 causes a mechanical stress 25 on the shaft 18, which is recorded in the form of measurement data 27 and sent to a processing unit 49 of the control unit 40. By means of the processing unit 49, which can be assigned individually or modularly to the internal and / or higher-level control unit 42, 44, a damage contribution 35 is determined in a second method step 120. The damage contribution 35 corresponds to damage to the monitored transmission component 12, i.e. the shaft 18, which is caused by the recorded mechanical stress 25.The damage contribution 35 is determined within the framework of a respective damage accumulation model 30, which can be set for the transmission component 12.

[0036] The damage accumulation model 30 for the corresponding transmission component 12 is in FIG 2 represented by the left-hand diagram. It comprises a horizontal load cycle change axis 31 and a vertical intensity axis 32 for acting load cycles. The damage accumulation model 30 also includes model boundary lines 33, each of which is assigned to a first or second damage mechanism 38, 39. The model boundary lines 33 specify the damage sum 43 at which the damage accumulation model 30 assumes failure of the transmission component 12 for the corresponding damage mechanism 38, 39. This can be, for example, LCF and HCF, wear, tooth root fracture, or pitting on a gearing. The damage contribution 35 determined in the second method step 120, which occurs in operating condition 20, is added to an already existing damage sum 43 in a damage group 34 in the existing damage accumulation model 30 in a third method step 130. The damage amount 43 is, as in FIG 1 shown, an aggregation of damages in individual damage groups 34 of varying intensity. Furthermore, in a fourth method step 140, the remaining model service life 36 of the transmission component 12 is determined for an adjustable load level 29. This determination of the remaining model service life 36 is shown in FIG 2 also illustrated by the arrows 48, the length of which extends from a block of the corresponding damage group 34 corresponding to the load level 29 to the model boundary line 33 of the first or second damage mechanism 38, 39. From this, corresponding model total lifetimes 41 of the transmission component 12 result from the corresponding model remaining lifetimes 36 for the first and second damage mechanism 38, 39.

[0037] Based on the model remaining lifetimes 36 for the first and second damage mechanisms 38, 39, and thus the model total lifetimes 41 of the transmission component 12, the probabilities 57 of occurrence are determined that the transmission component 12 actually reaches the corresponding model total lifetime 41. This is shown in FIG 2 shown in the right-hand distribution diagram 50, which comprises a horizontal service life axis 53 and a vertical frequency axis 52. The diagram also has a curve of a distribution function 51, which represents the frequency with which a certain damage sum 43 is reached during operation for comparison components 62 identical in construction to the transmission component 12. In the distribution diagram 50, in the fourth method step 140, a vertical line 47 specifies which model total service life 41 is required of the transmission component 12 for a first or second damage mechanism 38, 39 and a previously determined model remaining service life 36. This results in a survival range 55 and a failure range 54 for the damage mechanisms 38, 39 in the distribution diagram 50.The respective area under the distribution function 51 in the corresponding survival region 55 corresponds to a probability of occurrence 57 with which the transmission component 12 exceeds a required model remaining service life 36 for the respective damage mechanism 38, 39. Consequently, it can be determined with what probability the transmission component 12 will also achieve the required model remaining service life 36. The distribution function 51 is specified by a plurality of data sets 64 of comparison components 62, which are stored in a database 60. The data sets 64 are continuously updated using a plurality of comparison components 62, so that the experiences of users of identical comparison components 62 can be used for the transmission component 12.Such an updated distribution function 51 allows, among other things, unexpectedly long service lives, i.e., unexpectedly high damage amounts 43 up to failure, of transmission components 12 during operation to be exploited. Conversely, surprisingly short service lives, i.e., low damage amounts 43 up to failure, can be taken into account. By continuously updating the distribution function 51 using comparison components 62, a dynamic monitoring system 90 is implemented that becomes more reliable and precise in predicting failure of transmission components 12 with increasing operating time.

[0038] FIG 3 shows schematically a further aspect of the fifth method step 150 of the claimed method 100. In particular, the FIG 3 The evaluation diagram 70 shown shows a warning or reaction behavior of the method 100. The evaluation diagram 70 comprises a horizontal time axis 71 and a vertical value axis 72, on which a model remaining lifetime 36 and a probability of occurrence 57 are plotted. Both values ​​are in FIG 4 for the first damage mechanism 38 and relate to a transmission component 12, which can be designed as a gear 14, a shaft 16, or a bearing 18. The transmission component 12 is further subjected to a predeterminable load level 29 along the time axis 71. The model remaining service life 36 and the probability of occurrence 57 decrease along the time axis 71. An adjustable first threshold value 75 is defined for both the model remaining service life 36. If the model remaining service life 36 falls below the first threshold value 75, a warning 65 and / or a stockpiling instruction 66 is triggered. This warns a user of an impending failure of the transmission component 12 or prompts the provision of a replacement part. In an analogous manner, an adjustable second threshold value 76 is specified for the probability of occurrence 57.If the probability of occurrence 57 falls below the second threshold value 76, a warning 65 and / or a stocking instruction 66 is also issued for the transmission component 12. The first and second threshold values ​​75, 76 belong to the parameters 73, which are defined as shown in . FIG 1 shown, influence the course of the method 100 and can be specified by a user input 78 or an algorithm 79.

[0039] In FIG 4 The sequence of a second embodiment of the claimed method 100 is shown schematically. The method 100 is based on a first method step 110 in which the transmission 10 is provided with the plurality of transmission components 12, wherein at least a first transmission component 12 is to be monitored. The transmission 10 is in an operating state 20 in which a mechanical stress 25 on the first transmission component 12 is determined using a sensor 22. This is followed by a second method step 120 in which, based on the mechanical stress 25, a corresponding damage contribution 35 is determined within the framework of an adjustable damage accumulation model 30 and an adjustable first damage mechanism 38.In a subsequent third method step 130, the damage contribution 35 is added to a damage sum 43 in the damage accumulation model 30 for the first damage mechanism 38. In a subsequent fourth method step 140, a model remaining service life 36 is determined for the first damage mechanism 38 within the framework of the damage accumulation model 30. Likewise, in the fourth method step 140, a probability of occurrence 57 for the corresponding model remaining service life 36 is determined. The determination of the model remaining service life 36 and its probability of occurrence 57 is based on an adjustable load level 29, which corresponds to an expected or desired future operation of the transmission component 12, and thus of the transmission 10. The probability of occurrence 57 is determined on the basis of data sets 64 of comparison components 62, which provide a distribution function 51 of lifetimes.Parallel to the fourth method step 140, a sixth method step 160 takes place, in which, based on the model remaining service life 36 and the probability of occurrence 57, a cost forecast 67 for a maintenance process for the first transmission component 12 is performed. The result of the cost forecast 67 can be displayed to a user. The fourth method step 140 is followed by a first branch 145, at which the model remaining service life 36 and / or the probability of occurrence 57 from the fourth method step 140 are compared with adjustable parameters 73. The adjustable parameters 73 also include a first and a second threshold value 75, 76 for the model remaining lifetime 36 and the probability of occurrence 57, respectively. If the threshold values ​​75, 76 are exceeded, it is recognized that there is no operating state requiring a reaction, and the method 100 returns to the first method step 110 via a feedback loop 170.If the model remaining service life 36 or the probability of occurrence 57 falls below the first and / or second threshold value 75, 76, a fifth method step 150 occurs. A warning 65 is issued therein and / or a stockpiling instruction 66 is issued for the first transmission component 12. The method 100 then reaches a final state 200. The method 100 according to . FIG 4 runs entirely or functionally divided in one or more computer program products 80, which are stored in a non-volatile and executable manner on a control unit 40. The control unit 40 comprises an internal control unit 42 and / or a higher-level control unit 44.

[0040] FIG 5 shows a schematic sequence of a third embodiment of the claimed method 100. The method 100 is based on a first method step 110 in which a mechanical stress 25 of a first transmission component 12.1 in an operating state 20 is determined by means of a sensor 22. Using a transfer function 83, a mechanical stress 25 of a second transmission component 12.2 in the same operating state 20 is determined from this. The first and second transmission components 12.1 and 12.2 belong to the same transmission 10. A transfer function 83 is to be understood as a physical relationship between the first and second transmission components 12.1, 12.2, which describes a mechanical stress 25 of the first transmission component 12.1 essentially as a function of the mechanical stress 25 of the second transmission component 12.2.Such a transfer function 83 can be implemented as a value table, as an algorithm 79, or as a simulation. Based on the mechanical stress 25 on the second transmission component 12.2, the second, third, fourth, fifth, and sixth method steps 120, 130, 140, 150, and 160 are carried out analogously to . FIG 4 .

[0041] The first method step 110 is followed by a second method step 120, in which, based on the mechanical stress 25, a corresponding damage contribution 35 is determined within the framework of an adjustable damage accumulation model 30 and an adjustable first damage mechanism 38. In a subsequent third method step 130, the damage contribution 35 is added to a damage sum 43 in the damage accumulation model 30 for the first damage mechanism 38. In a subsequent fourth method step 140, a model remaining service life 36 is determined for the first damage mechanism 38 within the framework of the damage accumulation model 30. Likewise, in the fourth method step 140, a probability of occurrence 57 for the corresponding model remaining service life 36 is determined.The determination of the model remaining service life 36 and its probability of occurrence 57 is based on an adjustable load level 29, which corresponds to an expected or desired future operation of the second transmission component 12.2, and thus of the transmission 10. The probability of occurrence 57 is determined using data sets 64 of comparison components 62, which provide a distribution function 51 of service lives. Parallel to the fourth method step 140, a sixth method step 160 takes place in which, based on the model remaining service life 36 and the probability of occurrence 57, a cost forecast 67 for a maintenance process for the second transmission component 12.2 is performed. The result of the cost forecast 67 can be displayed to a user.The fourth method step 140 is followed by a first branch 145, at which the model remaining service life 36 and / or the probability of occurrence 57 from the fourth method step 140 are compared with adjustable parameters 73. The adjustable parameters 73 also include a first and a second threshold value 75, 76 for the model remaining service life 36 and the probability of occurrence 57, respectively. If the threshold values ​​75, 76 are exceeded, it is recognized that no operating state exists that requires a reaction, and the method 100 returns to the first method step 110 via a feedback loop 170. If the model remaining service life 36 or the probability of occurrence 57 falls below the first and / or second threshold value 75, 76, a fifth method step 150 is carried out. In this step, a warning 65 is issued and / or a stockpiling instruction 66 is issued for the second transmission component 12.2.The method 100 then reaches a final state 200. The method 100 according to . FIG 5 runs entirely or functionally divided in one or more computer program products 80, which are stored in a non-volatile and executable manner on a control unit 40. The control unit 40 comprises an internal control unit 42 and / or a higher-level control unit 44.

[0042] The structure of a first embodiment of the claimed monitoring system 90 is shown in FIG 6 shown. The monitoring system 90 comprises a plurality of sensors 22 which are designed to directly or indirectly detect a mechanical stress 25 on a transmission component 12 of a transmission 10. For this purpose, measurement data 27 is transmitted from the sensors 22 to a control unit 40, which includes an internal control unit 42. A computer program product 80 is stored in a memory of the internal control unit 42 in a non-volatile form in an executable manner. The internal control unit 42 is designed to receive the measurement data 27 from the sensors 22 and to process it with the computer program product 80. The computer program product 80 has a first subprogram 82 which is stored in a non-volatile, executable manner on the first control unit 42.

[0043] The claimed method 100 is partially implemented in at least one embodiment by the first subprogram 82. The first subprogram 82 is communicatively coupled to a higher-level control unit 44 via a data connection 45. Furthermore, a second subprogram 84 is stored non-volatilely and executably on the higher-level control unit 44, which belongs to the same computer program product 80 as the first subprogram 82. The communicative data connection 45 between the internal and higher-level control units 42, 44 enables communication between the first and second subprograms 82, 84. The second subprogram 84 partially implements the claimed method 100. Through the communicative data connection 45, the first and second subprograms 82, 84 interact to completely implement the claimed method 100. For this purpose, the first and second subprograms 82, 84 exchange parameters 73, values ​​from specifications 77 and / or values ​​from algorithms 79.

[0044] FIG 7 shows a schematic structure of a claimed transmission application 95, which comprises a drive unit 96, an output unit 97, and a transmission 10. The transmission 10 is mounted between the drive unit 96 and the output unit 97. Through the transmission 10, a drive power 21 from the drive unit 96, modified in terms of speed and torque, is transmitted as output power 23 to the output unit 97. The transmission application 95 can be designed as an industrial application, as a wind turbine, as a land vehicle, as a watercraft, or as an aircraft.

Claims

1. Operating method (100) for a transmission (10) for a transmission application which is configured as a wind power plant or an industrial application and has a plurality of transmission components (12, 12.1, 12.2) comprising the steps: a) establishing an operating state (20) of the transmission (10) and detecting a corresponding mechanical load (25) of a first transmission component (12, 12.1); b) determining a degradation contribution (35) at the first transmission component (12, 12.1) on the basis of the determined mechanical load (25) for a first degradation mechanism (38); c) adding the degradation contribution (35) to a damage sum (43) in a first damage accumulation model (30) of the first degradation mechanism (38); d) determining a model remaining service life (36) of the first transmission component (12, 12.1) on the basis of the first damage accumulation model (30), and determining an occurrence probability (57) for the model remaining service life (36); wherein the occurrence probability (57) is determined for the model remaining service life (36) on the basis of data sets (64) of comparison components (62) which are of structurally identical configuration with respect to the first transmission component (12, 12.1), wherein, in step b), a degradation contribution (35) is also determined for a second degradation mechanism (39), and steps c) and d) are also carried out on the basis of this degradation contribution for a second degradation mechanism (39), which comprises determining a damage sum (43) for the second degradation mechanism (39), characterized in that at least one model service life (36) and its occurrence probability (57) are stored in a data set (64) which has an information item about the type of the corresponding degradation mechanism, wherein the data set (64) for structurally identical further transmission components (62) serves as a comparative data set (64) and the comparative components (62) are used in different transmissions, wherein the different transmission is a transmission which is different from the transmission (10) in a different transmission application.

2. Operating method (100) according to Claim 1, characterized in that at least one detected mechanical load (25) is stored in the data set (64).

3. Operating method (100) according to Claim 1 or 2, characterized in that at least one degradation contribution (25) and / or at least one damage sum (43) are / is stored in the data set (64).

4. Operating method (100) according to Claims 1 to 3, characterized in that, in a further step e), a warning (65) is output if the model remaining service life (36) undershoots an adjustable first threshold value (75) and / or the occurrence probability (57) undershoots an adjustable second threshold value (76).

5. Operating method (100) according to one of Claims 1 to 4, characterized in that, in step b), a mechanical load (25) of the second transmission component (12.2) is determined on the basis of the mechanical load (25) of the first transmission component (12, 12.1) using a transfer function (83), and at least steps c) and d) are also carried out for the second transmission component (12.2).

6. Operating method (100) according to one of Claims 1 to 5, characterized in that the first or second degradation mechanism (38, 39) is configured as high-cycle fatigue, low-cycle fatigue, wear, tooth root fracture or pitting on a toothing system.

7. Operating method (100) according to one of Claims 1 to 6, characterized in that the occurrence probability (57) for the model remaining service life (36) is determined on the basis of a distribution function (51) of permissible damage sums (43) of the comparative components (62).

8. Operating method (100) according to one of Claims 1 to 7, characterized in that the damage sum (43) is adjustable by means of an algorithm (79) and / or a user input (78).

9. Operating method (100) according to one of Claims 1 to 8, characterized in that a scope of repair (67) to be expected is determined for the first transmission component (12, 121) and / or the transmission (10) by means of the model remaining service life (36) and / or its occurrence probability (57).

10. Operating method (100) according to Claim 9, characterized in that a stocking order (66) is output to a material management system (68) at least for the first transmission component (12, 12.1).

11. Operating method (100) according to one of Claims 1 to 10, characterized in that the model remaining service life (36) and / or its occurrence probability (57) are / is determined on the basis of an adjustable load level (29) for further operation of the first transmission component (12, 12.1).

12. Computer program product (80), comprising at least one subprogram (82) which is configured to carry out an operating method (100) for a transmission (10) completely or at least partially with a data link (45) to a second subprogram (84), characterized in that the operating method (100) is configured according to one of Claims 1 to 11.

13. Control unit (40) for a transmission (10), which control unit has a memory and a computing unit for running a computer program product (80), characterized in that the computer program product (90) is configured according to Claim 12, and in that the control unit (40) is arranged as an internal control unit (42) in the transmission (10), or is installed separately from the transmission (10) as a higher-level control unit (44).

14. Monitoring system (90) for a transmission (10), which monitoring system can be coupled to at least a first transmission component (12, 12.1) to be monitored, comprising: a plurality of sensors (22) for detecting measurement data (27) which correspond to a mechanical load (25) of the first transmission component (12, 12.1); and at least one control unit (40) which is connected to the plurality of sensors (22) and is configured as an internal control unit (42) and / or a higher-level control unit (44), characterized in that the control unit (44) is configured according to Claim 13.

15. Transmission (10), comprising a plurality of transmission components (12, 12.1, 12.2), wherein at least one first transmission component (12, 12.1) is coupled to at least one sensor (22), wherein the sensor (22) is assigned to a monitoring system (90), characterized in that the monitoring system (90) is configured according to Claim 14.

16. Transmission application (95), comprising a transmission (10) which is arranged between a drive unit (96) and an output unit (97) in order to change the rotational speed, wherein the transmission application (95) is configured as a wind power plant or an industrial application, characterized in that the transmission (10) is configured according to Claim 15.