METHOD AND SYSTEM FOR THE INDIRECT DETECTION OF WEAR IN A SLIDING POWER CONDITIONING CHAIN

Abstract

The invention relates to a method and a system (10) for indirectly detecting wear of an energy chain (12). The system (10) comprises a preferably stationary sensor assembly (28) and an analysis device (30) which is connected to the sensor assembly (28) so as to transmit signals. The sensor assembly (28) is arranged and designed such that on the basis of at least one feature of the chain links (26), said feature repeatedly occurring or being detectable periodically, in particular in a manner corresponding to the chain pitch of the energy chain (12), when the energy chain is moved relative to the sensor assembly, the sensor assembly generates corresponding output signals which are evaluated by the analysis device (30).

Description

[0001] Method and system for indirect detection of wear of a sliding energy chain

[0002] The invention generally relates to a system and a method for monitoring or condition monitoring of a movable or dynamic cable guide, in particular an energy guide chain, for guiding at least one line, such as a cable, hose or the like, between a stationary fixed point and a driver that is movable relative to it, typically on a movable part of a system or machine.

[0003] The invention particularly relates to a system and a method for the indirect detection of wear during operation of the energy chain, so that predictive maintenance is enabled.

[0004] During the process, the energy chain typically consists of a stationary lower strand, a movable upper strand, and a moving deflection bend between them. The invention particularly relates to energy chains with a sliding upper strand for long travel distances.

[0005] For wear detection, solutions are known in which special sensor modules are installed in the cable guide device or energy guide chain, such as in

[0006] WO 2017 / 129805 Al or WO 2019 / 201482 Al have been proposed. However, these solutions require structural modifications to the energy chain and available installation space in the internal housing for the cables. Another approach to wear monitoring was proposed in WO 2021 / 043668 Al, but this also requires structural modifications to the energy chain, and this approach is only suitable for sliding energy chains with sliding shoes. Furthermore, EP 1 521 015 A2 presents an approach to wear monitoring in which a wear element with a predetermined breaking point is used to determine whether the chain is at a critical level of wear. The predetermined breaking point is the indicator used to indicate a critical wear condition of the chain.

[0007] In DE 20 2016 000 501 Ul an approach as in

[0008] WO 2017 / 129805 A1 presented a wear element designed as a transponder. DE 20 2016 107 317 U1 and WO 2018 / 115528 A1 presented an approach in which the path of the chain is monitored, but this approach is not readily suitable for wear detection.

[0009] What is desired is a structurally simple solution for detecting wear during operation of different energy chains, one that is as versatile as possible and can be implemented with an existing energy chain without structural measures, modifications, or alterations. In particular, wear monitoring should be possible for the typical joints between chain links without requiring any modification of the energy chain.

[0010] This object is achieved by a system according to claim 1 and a method according to claim 11. Preferred embodiments and further developing features are specified in subclaims 2 to 10 and 11 to 20, respectively. Further features emerge in particular from these dependent patent claims.

[0011] The invention is based on a system for indirect wear detection on a cable guide chain. The cable guide chain typically serves to guide at least one line, such as a cable, hose, or the like, between a stationary fixed point and a relatively movable carrier, wherein the cable guide chain is movable to form a stationary lower run, a movable upper run, and a deflection bend between them. The cable guide chain is designed and arranged with a sliding upper run, particularly for long travel distances. A sliding upper run is also understood here to mean an upper run rolling on the lower run.

[0012] It is proposed that the sensor arrangement comprise at least two sensors, each arranged and configured such that the sensors generate corresponding output signals depending on at least one feature that periodically occurs or can be detected during the movement of the energy chain relative to the sensor arrangement, in particular corresponding to the chain pitch of the energy chain. The signals are then evaluated by the evaluation device. The evaluation device is configured to detect and evaluate the temporal behavior of the output signals of the individual sensors. The system preferably comprises a preferably stationary sensor arrangement and an evaluation device that is connected to the sensor arrangement for signal transmission.

[0013] According to the invention, the sensor arrangement is arranged and configured to generate corresponding output signals, which the evaluation device evaluates, depending on at least one feature that occurs periodically during the movement, in particular during the movement, of the energy guide chain relative to the sensor arrangement, in particular in accordance with the chain pitch of the energy guide chain. In particular, the invention allows the temporal behavior of the energy guide chain to be detected and advantageously evaluated using at least two sensors, e.g., to determine increasing wear, which can be indirectly detected by changes in the temporal behavior.

[0014] The feature can in particular be a design feature of the energy chain, in particular of the individual chain link. It is preferably an inherent

[0015] A design feature of the energy chain that occurs repeatedly along the chain's length. This design feature can occur multiple times along the entire length of the chain, e.g., on every chain link or every other chain link, and e.g., over almost the entire length between the end attachments.

[0016] The system is preferably arranged and configured for indirect wear detection on at least one chain link of the energy chain, preferably for detecting wear on a connection between at least two chain links of the energy chain. The energy chain preferably has a plurality of chain links, such as several tens or well over a hundred, which are preferably all structurally identical (with so-called offset plates or forked plates) or alternately structurally identical (e.g., with alternating inner and outer plates), possibly with the exception of end connection links.

[0017] The invention offers many advantages. In particular, the wear condition of individual chain links can be advantageously detected. This allows for targeted replacement of only parts of the energy chain during maintenance, or, for example, for more heavily stressed chain links to be replaced with less stressed chain links during maintenance. This can, for example, increase the overall service life and sustainability of the energy chain.

[0018] Preferably, the system for indirect wear detection on the energy chain is arranged between a stationary fixed point of the energy chain and a carrier of the energy chain that is movable relative thereto.

[0019] Typically, at least one end of the energy guiding chain is movable, in particular displaceable, along a longitudinal axis of the energy guiding chain, in particular relative to at least one other end of the energy guiding chain. Preferably, the stationary

[0020] Fixed point of the energy chain at one end of the

[0021] Energy guiding chain. Preferably, the driver of the energy guiding chain is arranged at another end of the energy guiding chain. Typically, the driver forms one end of the energy guiding chain. Conceptually, the energy guiding chain can be divided into at least three different regions during the process. Preferably, one of the at least three regions is a stationary lower run, which extends from one end, in particular the end at which the stationary fixed point is arranged, of the energy guiding chain to the deflection bend and which is formed in particular by a part of the energy guiding chain extending parallel to the longitudinal axis of the energy guiding chain. Preferably, the region of the energy guiding chain which forms the stationary lower run is stationary only with respect to the end at which the stationary fixed point is arranged.

[0022] The system for indirect wear detection is preferably arranged at the fixed point in the imaginary extension of the stationary lower run, such that the movable upper run moves past, in particular above, the sensor arrangement of the system and / or moves through the detection range of the sensor arrangement.

[0023] Preferably, one of the at least three regions is a movable upper run, which extends from one end, in particular the end at which the driver is arranged, of the energy guiding chain to the deflection bend and which is formed in particular by a part of the energy guiding chain extending parallel to the longitudinal axis of the energy guiding chain. Preferably, one of the at least three regions is a deflection bend arranged between the other regions of the energy guiding chain, preferably the stationary lower run and the movable upper run, which in particular forms a bend (so-called deflection bend) of the energy guiding chain that extends over an angular dimension of approximately 180°. The upper run is preferably mounted so as to slide on the lower run.Alternatively or additionally, the upper run can be mounted on the lower run in a rolling manner, in particular by means of at least one roller element - whereby a rolling upper run is understood here under the collective term sliding upper run.

[0024] The system preferably comprises a sensor arrangement arranged stationary, particularly relative to the energy chain. The system preferably comprises an evaluation device designed and arranged separately from the sensor arrangement. The evaluation device is preferably connected to the sensor arrangement for signal transmission, particularly for data transmission, preferably at least from the sensor arrangement to the evaluation device. During operation, the sensor arrangement preferably transmits a continuous signal to the evaluation device, for example, in real time or as a periodic signal with a suitable transmission frequency of at least 20 Hz, preferably at least 50 Hz.

[0025] Preferably, the sensor arrangement is arranged and configured to generate corresponding output signals depending on at least one feature of the energy guide chain, which output signals are evaluated by the evaluation device. Preferably, the sensor arrangement is configured to generate corresponding output signals depending on at least one feature of the energy guide chain and to send them to the evaluation device. Preferably, the feature of the energy guide chain occurs periodically during the displacement, in particular movement, of the energy guide chain relative to the sensor arrangement, in particular repeatedly, in accordance with the chain pitch of the energy guide chain. Preferably, the at least one feature of the energy guide chain is a feature which is selected such that it occurs on each chain link of the energy guide chain, in particular at the same point on the chain link.

[0026] Preferably, the feature of the energy guide chain can be repeatedly detected periodically, in particular according to the pitch of the energy guide chain, during the movement, in particular during the movement, of the energy guide chain relative to the sensor arrangement. For example, the at least one feature of the energy guide chain can be selected as a respective element of the chain links located inside the deflection curve. For example, the at least one feature of the energy guide chain can be formed as a label on the chain links.

[0027] Particularly preferably, the at least one feature of the energy chain is a crosspiece or a component of the crosspiece, which is inherently provided on each or every nth chain link. The crosspiece is inherently optically and / or electromagnetically detectable without the need for modification.

[0028] Additionally or alternatively, the at least one feature of the energy guide chain can be provided as a feature that can be added with little effort. For example, a code, such as a barcode and / or QR code, can be formed on the chain links. For example, the at least one feature of the energy guide chain can be formed as an optical element on the chain links, in particular for generating an optical signal, preferably an electromagnetic signal, for example in the visible optical spectrum, preferably in the infrared spectrum, particularly preferably outside the invisible spectrum.

[0029] Other designs are also conceivable. For example, the sensor arrangement can be configured to detect at least optical, preferably electromagnetic, signals. For example, the at least one feature of the energy guide chain can be designed as an acoustic element of a chain link, in particular for generating an acoustic signal, for example in the audible signal frequency spectrum, preferably in the inaudible signal frequency spectrum, e.g. in the ultrasound range, alternatively in the infrasound range. In particular, the sensor arrangement can be configured to detect at least acoustic signals, in particular sound waves or structure-borne sound. In this case, driving noise inherently generated during processes can also be monitored without special or additional acoustic elements being provided.

[0030] The sensor arrangement is preferably designed to monitor the energy guide chain, in particular the at least one feature of the energy guide chain, preferably of each link of the energy guide chain, during the movement of the energy guide chain. The sensor arrangement preferably has at least one, preferably at least two, sensors designed to detect at least one feature of the energy guide chain during the movement of the energy guide chain.

[0031] Particularly preferably, the evaluation device is designed to determine a distance between two chain links of the energy guide chain from the output signals which the evaluation device receives from the sensor arrangement.

[0032] Preferably, the evaluation device is designed to determine an instantaneous speed of the chain links, for example individual chain links or two chain links each, of the energy guide chain from the output signals which the evaluation device receives from the sensor arrangement.

[0033] Preferably, the evaluation device is designed to standardize the determined distances between two chain links by means of determined instantaneous speeds, in particular of the chain links under consideration.

[0034] Particularly preferably, the evaluation device is designed to determine a wear condition of the energy guide chain, in particular of the chain links of the energy guide chain, from determined, in particular standardized, distances between the chain links of the energy guide chain.

[0035] In a further development, the evaluation device is designed to determine a change in the instantaneous speed of the chain links of the energy guide chain from the output signals that the evaluation device receives from the sensor arrangement. In this case, the evaluation device can be designed to determine a wear condition of the energy guide chain, in particular of the chain links of the energy guide chain, from the determined changes in the instantaneous speed of the chain links of the energy guide chain. For example, during a change of direction of the energy guide chain, the speed is recorded more slowly between chain links connected with play due to wear than between chain links connected in the new condition with play caused only by manufacturing tolerances.

[0036] For example, the wear condition of the connection between two chain links can be determined from the acceleration of individual chain links.

[0037] In particular, a frequency, preferably a frequency change, of the signals from the sensor arrangement can be used to achieve a particularly advantageously relatively accurate determination of the speeds and accelerations of the chain links. In particular, frequency effects, such as a Doppler effect, can be used to achieve a particularly advantageously particularly accurate determination of the speeds and accelerations of the chain links. In particular, the evaluation device can be designed to determine, and preferably average, the wear condition of the energy guide chain, in particular of the chain links of the energy guide chain, from the particularly standardized distances between the chain links of the energy guide chain and from determined changes in the instantaneous speed of the chain links of the energy guide chain.

[0038] A "longitudinal axis" of an object is to be understood in particular as an axis which runs parallel to a longest edge of a smallest, imaginary, geometric cuboid which just completely encloses the object, and preferably runs through a geometric center of the object, in particular of the cuboid.

[0039] The evaluation device comprises in particular at least one processor and / or at least one processor unit, at least one memory unit, and an operating, control and / or calculation program stored in the memory unit.

[0040] Preferably, the at least two sensors, in particular of the sensor arrangement, are each arranged such that the sensors detect at least one feature that occurs periodically, in particular corresponding to the chain pitch of the energy guide chain, when the energy guide chain is moved relative to the sensor arrangement. Preferably, the at least two sensors, in particular of the sensor arrangement, are each configured to generate corresponding output signals depending on the at least one feature. Preferably, the evaluation device is designed to evaluate the output signals. Particularly preferably, the evaluation device is configured to detect and evaluate the temporal behavior of the output signals of the individual sensors.

[0041] The inventive design of the system for indirect wear detection on a cable guide chain enables advantageous, precise monitoring of the wear condition of the cable guide chain. In particular, advantageous, cost-effective early detection of an impending break in the cable guide chain can be achieved.

[0042] Furthermore, it is proposed that the at least two sensors be spaced apart from one another in the direction of travel and arranged and configured such that each of the sensors detects the presence of passing transverse webs of the energy guide chain and outputs a corresponding output signal. Preferably, the sensor arrangement comprises a plurality of sensors spaced apart from one another in the direction of travel and is arranged such that each of the sensors detects the presence of passing features of the energy guide chain, in particular transverse webs as the at least one feature of the energy guide chain, and outputs a corresponding output signal.The sensor arrangement preferably comprises a plurality of, preferably at least two, in particular at least three, sensors, which are preferably arranged at a distance from one another in the direction of travel of the energy guide chain, preferably which are arranged at least partially and / or at least completely offset from one another in the direction of travel of the energy guide chain. Each of the sensors preferably detects the presence of the at least one feature under consideration, for example passing crosspieces, of the energy guide chain. Each of the sensors preferably outputs an output signal corresponding to the detected presence or absence of the same at least one feature, for example the passing crosspiece, of the energy guide chain. Advantageously, long-term uninterrupted detection of the at least one feature of the energy guide chain can be achieved.

[0043] It is further proposed that the sensors be designed as electromagnetic, in particular capacitive, proximity sensors. Preferably, the sensors of the sensor arrangement are functionally identical and / or structurally identical.

[0044] The sensors of the sensor arrangement can alternatively and / or additionally be designed as inductive proximity sensors, acoustic sensors, light barriers, in particular infrared light barriers, or the like. This allows for advantageously fast, particularly high-resolution, monitoring of the energy chain.

[0045] Furthermore, it is proposed that at least two sensors of the sensor arrangement are arranged at a distance corresponding to the nominal (as new) chain pitch and / or are arranged and configured to detect a feature that is dependent on the chain pitch. Preferably, at least two sensors are provided and / or two sensors are arranged at a distance corresponding to the nominal, in particular with respect to a as new, chain pitch. Preferably, the sensor arrangement has at least two sensors which are offset from one another along the direction of travel, in particular along the longitudinal axis of the energy guide chain, at a distance corresponding to the nominal, in particular with respect to a as new, chain pitch. Preferably, the system for indirect wear detection on the energy guide chain comprises the energy guide chain.Preferably, the geometric centers of at least two sensors are offset from one another along the travel direction, in particular along the longitudinal axis of the energy chain, at a distance corresponding to the nominal chain pitch, in particular with respect to a new chain pitch. Two chain links can be detected simultaneously in order to advantageously monitor the distance between the two chain links.

[0046] Furthermore, in a preferred development, it is proposed that the sensor arrangement be arranged stationary next to the fixed point in the direction of travel of the energy guide chain. The sensor arrangement is preferably connected in a stationary manner to a support unit, in particular a rail unit, for the energy guide chain. The sensor arrangement is preferably arranged stationary next to the fixed point for monitoring the upper run of the energy guide chain in the direction of travel of the energy guide chain. Typically, the stationary fixed point of the energy guide chain is arranged on the lower run of the energy guide chain. The sensor arrangement is preferably arranged offset from the stationary fixed point in the direction of travel of the energy guide chain, in particular along the longitudinal axis of the energy guide chain.The rail unit preferably has at least two rails aligned parallel to the longitudinal axis of the energy guide chain, on which the energy guide chain is mounted and to which the sensor arrangement is mechanically connected or with respect to which the sensor arrangement is fixed. Preferably, the stationary fixed point of the energy guide chain is connected to the rail unit offset from the sensor arrangement along the longitudinal axis of the rail unit. This allows advantageous monitoring of the upper strand during the movement of the energy guide chain.

[0047] It is further proposed that the evaluation device detects the instantaneous speed of individual chain links from the temporal behavior of the output signals and / or wherein the evaluation device comprises three sensors, wherein two sensors of the sensor arrangement are arranged at a distance corresponding to the nominal chain pitch and a third sensor is provided for detecting the direction of travel. Preferably, the evaluation device detects and / or determines the temporal behavior of the output signals of the sensor arrangement, in particular of individual sensors, and / or detects, preferably determines, the instantaneous speed of individual chain links from the output signals. Preferably, the evaluation device determines a wear condition of a connection between the two chain links from the distances, in particular in combination with the instantaneous speeds, of two adjacent chain links.Preferably, a third sensor, in particular of the sensor arrangement, is designed to detect a direction of travel, which in particular corresponds to the current direction of travel, of the energy guide chain. Preferably, a third sensor, in particular of the sensor arrangement, is designed to detect a direction of travel, in particular the current direction of travel of the energy guide chain, if necessary directly, and to transmit it to the evaluation device. Alternatively or additionally, the evaluation device can be designed to determine the direction of travel, which in particular corresponds to the current direction of travel, of the energy guide chain from the output signals of the third sensor, if necessary in cooperation with the output signals of one of the other two sensors. Alternatively or additionally, the current direction of travel or direction of movement, e.g.forward into the extended position or back into the retracted position, of the moving strand of the energy chain can also be determined by or using one or both of the first-mentioned sensors.

[0048] It is advantageous to monitor the wear of a cable guide chain independently of speed, particularly on the chain links that are known to be most vulnerable, e.g., in the first third of the chain length on the driver side. A preferred design feature is an inherent characteristic of the chain that occurs repeatedly at least in this first third.

[0049] It is further proposed that the evaluation device

[0050] The evaluation device evaluates output signals from the sensor arrangement for deviations from a pre-stored behavior or reference values ​​of a new energy chain. Preferably, the evaluation device comprises at least one memory module on which data with reference values ​​or standard values ​​corresponding to a new energy chain are stored, preferably pre-stored. This allows for an advantageously rapid detection of malfunctions in the energy chain.

[0051] Furthermore, it is proposed that the evaluation device determines the distance between successive chain links by measuring time intervals between the detection of the periodic characteristic and a respectively detected instantaneous speed, and preferably compares this distance with a predetermined, nominal chain pitch for the purpose of wear detection. Preferably, the evaluation device determines the standardized distance between successive chain links by measuring time intervals between the detection of the periodic characteristic and a respectively detected instantaneous speed. Preferably, the evaluation device compares each determined, and in particular standardized, distance with a predetermined, nominal chain pitch for wear detection on the corresponding chain links. This allows for advantageously precise detection of wear in an energy chain.

[0052] It is further proposed that the evaluation device issues a maintenance recommendation depending on the evaluation, in particular as a function of a currently detected distance between periodic features. The maintenance recommendation can be issued, for example, to a higher-level computer. The evaluation device preferably has an output module which is, for example, connected to a higher-level system in terms of data technology and / or can be designed as an optical, acoustic and / or haptic output module. The output module can be designed, for example, in addition to the acoustic output. The output module is preferably designed at least partly as a display and / or partly as a loudspeaker. The maintenance recommendation can, for example, be issued as an acoustic alarm tone. In addition or alternatively, the maintenance recommendation can be designed as a visual alarm signal. It can therefore, in particular in addition to a data-based message orA message can also be sent to a higher-level system, preferably with a visual and / or acoustic maintenance recommendation.

[0053] Furthermore, it is proposed that the sensor arrangement and the evaluation device detect a plurality of consecutive chain links for section-by-section wear detection. Preferably, the sensor arrangement is designed to continuously or permanently monitor the energy chain during a process or during operation of the energy chain, in particular to continuously detect at least one feature of the chain links. This advantageously allows for continuous monitoring of the chain links.

[0054] In addition, a method or process is proposed for indirect wear detection on the energy chain.

[0055] The method is based on a method for indirect wear detection on an energy guide chain, for guiding at least one line, such as a cable, hose or the like, between a stationary fixed point and a driver that is movable relative thereto, wherein the energy guide chain is movable to form a stationary lower run, a movable upper run and a deflection bend therebetween, and the energy guide chain is designed and arranged in particular with a sliding upper run, wherein a preferably stationary sensor arrangement is provided and an evaluation device is provided which is connected to the sensor arrangement in terms of signal technology.

[0056] It is proposed that the sensor arrangement comprises at least two sensors, each of which is arranged and set up in such a way that the sensors are able to detect the movement of the energy guide chain in dependence on at least one feature which is periodically measured during the movement of the energy guide chain relative to the sensor arrangement, in particular in accordance with the chain pitch of the

[0057] Energy chain, occurs repeatedly, corresponding

[0058] generate output signals,

[0059] - that in at least one method step, the sensor arrangement generates corresponding output signals depending on at least one such feature which periodically occurs or can be detected during the movement of the energy chain relative to the sensor arrangement, in particular in accordance with the chain pitch of the energy chain, which output signals are evaluated by the evaluation device, and

[0060] - that the evaluation device records and evaluates the temporal behavior of the output signals of the individual sensors.

[0061] Preferably, in at least one method step, the sensor arrangement generates corresponding output signals depending on the at least one feature which occurs periodically, in particular corresponding to the chain pitch of the energy guide chain, during the movement, in particular the planned movement, of the energy guide chain relative to the sensor arrangement and which is in particular detectable, and which are evaluated by the evaluation device. Preferably, in at least one method step, the sensor arrangement monitors the energy guide chain moving past the sensor arrangement. Preferably, in at least one method step, the sensor arrangement generates an output signal each time the at least one feature on a chain link is detected. Preferably, in at least one method step, at least each output signal is sent to the evaluation device.Preferably, in at least one method step, a continuous output signal is sent to the evaluation device, which assumes a defined value depending on the presence of the at least one feature and otherwise assumes a base value.

[0062] Furthermore, it is proposed that the sensors be arranged at a distance from one another in the direction of travel, and that in at least one method step, each sensor of the sensor arrangement detects the presence of passing crosspieces, in particular as the at least one feature, of the energy chain and outputs a corresponding output signal. This advantageously allows for long-term, uninterrupted detection of the at least one feature of the energy chain.

[0063] Furthermore, it is proposed that capacitive proximity sensors be used as the sensors of the sensor arrangement in at least one method step. This allows for advantageously fast, particularly high-resolution, monitoring of the energy chain.

[0064] It is further proposed that the at least two sensors of the sensor arrangement detect a feature that is dependent on the chain pitch. A third sensor can preferably be provided, the output signal of which is used, e.g., directly or indirectly, to detect the direction of travel.

[0065] Preferably, at least two sensors of the sensor array are used in at least one method step, and / or two sensors of the sensor array are used that are arranged at a distance corresponding to the nominal (as-new) chain pitch. Two chain links can be detected simultaneously in order to advantageously monitor the distance between the two chain links.

[0066] Furthermore, it is proposed that the sensor arrangement be used in at least one method step, which is arranged stationary next to the fixed point in the direction of travel of the energy chain. This allows advantageous monitoring of the upper strand during the movement of the energy chain.

[0067] Furthermore, it is proposed that in at least one method step the evaluation device detects the instantaneous speed of individual chain links from the temporal behavior of the output signals of individual sensors. Preferably, in at least one method step the evaluation device detects the temporal behavior of the output signals of the sensor arrangement, in particular of individual sensors, and / or the evaluation device detects the instantaneous speed of individual chain links from the output signals. Preferably, in at least one method step the evaluation device determines the instantaneous speed of individual chain links from the temporal behavior of the output signals, in particular of individual sensors, of the sensor arrangement.Preferably, in at least one method step, the evaluation device determines the distances, in particular speed-normalized, between individual chain links from the output signals, and in particular from the temporal behavior of the output signals, in particular from individual sensors, of the sensor arrangement. This advantageously enables rapid, in particular high-resolution, monitoring of the energy chain.

[0068] It is further proposed that, in at least one method step, the evaluation device evaluates the output signals of the sensor arrangement, in particular of individual sensors, for deviations from a pre-stored behavior of a new energy guide chain. Preferably, in at least one method step, the evaluation device compares at least one, preferably speed-normalized, distance between individual chain links with pre-stored distances of a new energy guide chain. Advantageously, speed-independent monitoring of the wear of an energy guide chain can be achieved, in particular on the chain links which, according to experience, are most at risk.

[0069] Furthermore, it is proposed that, in at least one method step, the evaluation device determines the distance between successive chain links by measuring time intervals between the detection of the periodic characteristic and, based on a respective detected instantaneous speed, preferably comparing the distance with a predetermined, nominal chain pitch for the purpose of wear detection. This advantageously allows for rapid detection of malfunctions in the energy chain.

[0070] It is further proposed that, in at least one method step, the evaluation device issues a maintenance recommendation based on the evaluation, in particular as a function of a currently detected distance between periodic features. A maintenance recommendation can advantageously be issued optically and / or acoustically.

[0071] Furthermore, it is proposed that, in at least one method step, a sensor arrangement and evaluation device detect a plurality of consecutive chain links for section-by-section wear detection. This advantageously allows continuous monitoring of the chain links. Further details and advantages of the individual aspects of the invention can be found, without limiting the generality of the above, in the following explanation of preferred embodiments with reference to the accompanying drawings. Features with corresponding or identical structure or function have corresponding reference numerals and may not be described repeatedly. Herein:

[0072] FIG.l: a side view of an energy guiding chain with sliding upper run;

[0073] FIG.2: a perspective view of a preferred embodiment of a system with a sensor arrangement with several sensors which detect the presence of passing crossbars of the energy guide chain.

[0074] FIG.3: schematically shows a sensor arrangement for several sensors with a hole pattern for different chain types;

[0075] FIG.4A-4D: show the temporal behavior of the individual sensors as the energy chain passes by; and

[0076] FIG. 5: shows a schematic of a method according to the invention. FIGS. 1-4 show an implementation of the basic principle for determining wear, e.g., due to increasing pin-bore clearance in the joint connection of the chain links by calculating the difference in the distance between the opening webs or cross webs between the pulling and pushing movements of the energy chain. The opening web distance corresponds to the time between the detection of two opening webs at the measured instantaneous speed.

[0077] FIG. 1 shows an energy guiding chain 12 (hereinafter referred to as EFK). One end 13 of the EFK 12 is movable along a longitudinal axis 14 of the EFK 12, in particular reciprocating, in particular relative to at least one other end 17 of the EFK 12. A stationary fixed point 16 of the EFK 12 is arranged at one end 17 of the EFK 12. A driver 18 of the EFK 12 is arranged at the other end 13 of the EFK 12. The driver 18 forms one end 13 of the EFK.

[0078] 12. The EFK 12 is arranged in such a way that when the driver 18 of the EFK 12 moves, the EFK 12 forms at least three different areas 20, 22, 24, which in the example shown correspond to the lower run, the deflection bend and the upper run.

[0079] One of the three areas 20, 22, 24 is a stationary lower run

[0080] 21, which extends from the end 17, at which the stationary fixed point 16 is arranged, of the EFK 12 to a deflection bend 23 and which is formed by a part of the EFK 12 extending parallel to the longitudinal axis 14 of the EFK 12. The region 20 of the EFK 12, which forms the stationary lower strand 21, is stationary only with respect to the end 17, at which the stationary fixed point 16 is arranged. One of the three regions 20,

[0081] 22, 24 is a movable upper run 25, which extends from the end

[0082] 13, on which the driver 18 is arranged, the EFK 12 extends to the deflection bend 23 and which is formed by a part of the 12 extending parallel to the longitudinal axis 14 of the EFK 12. The upper run 25 is slidably mounted on the lower run 21. One of the three regions 20, 22, 24 is a deflection bend 23 arranged between the stationary lower run 21 and the movable upper run 25, which forms a 180° bend of the EFK 12. However, the invention is also readily applicable to an EFK 12 with a movable lower run 21 and a stationary upper run 25.

[0083] For guiding one or more lines, such as cables, hoses or the like, the EFK 12 has a largely known structure. The EFK 12 comprises a plurality of chain links 26 which are articulated to one another transversely to the longitudinal axis 14. By way of example, only three chain links 26 are provided with a reference number. The EFK 12 has a movable end 13 on which the driver 18 is arranged. The EFK 12 has a fixed chain end 25 which is firmly flanged to a mostly spatially fixed base 11 of an external support structure. In an active state, the driver 18 moves back and forth, for example, along the longitudinal axis 14, in particular to the left and right in FIG. 1, relative to the stationary fixed point 16. The driver 18 is, for example, a movable connection point in a machine which is to be supplied with energy, data and / or media. Base 11 usually forms the fixed connection point.The carrier 18 could alternatively be vertically movable or movable along two axes. The EFK 12 forms a deflection curve 23, which moves along with the carrier movement. The deflection curve 23 is defined, for example, by a deflection pulley or, more commonly, by angle-limiting stops on the chain links 26.

[0084] FIG.2 shows a schematic diagram of a system, generally designated 10, for indirect wear detection on the EFK 12. The system 10 comprises the following main components: an EFK 12, an evaluation device 30, and a sensor arrangement 28 arranged on the EFK 12. The arrangement of the three sensors 18, 18', 18'' of the sensor arrangement 28 in FIG.2 is purely exemplary. The arrangement of the three sensors 18, 18', 18'' of the sensor arrangement 28 is described in more detail in FIG.3. The sensor arrangement 28 is connected to the evaluation device 30 for signal transmission.

[0085] FIG.2 shows, in particular, the system for indirect wear detection on the EFK 12. The EFK 12 is designed to guide at least one line 19, such as a cable, hose, or the like. The EFK 12 is designed to guide at least one line 19 between the stationary fixed point 16 and a driver 18 movable relative thereto. The EFK 12 is movable, forming a stationary lower run 21, a movable upper run 25, and a deflection bend 23 therebetween. The EFK 12 is designed and arranged on an upper run 25 sliding on the lower run.

[0086] The system 10 has a stationary sensor arrangement 28 and an evaluation device 30 which is connected to the sensor arrangement for signal transmission. The sensor arrangement is arranged and configured to generate corresponding output signals, which the evaluation device evaluates, depending on at least one feature which occurs periodically, in particular corresponding to the chain pitch of the EFK 12, during the displacement, in particular movement, of the EFK 12 relative to the sensor arrangement. The system 10 is designed for the indirect detection of wear on the chain links 26 of the EFK 12. The EFK 12 has, for example, more than twenty chain links 26, all of which are of identical construction. The system 10 is designed for the indirect detection of wear on the EFK 12 between the stationary fixed point 16 of the EFK 12 and a driver 18 of the EFK 12 which is movable relative thereto.

[0087] The system 10 comprises the sensor arrangement 28 arranged stationary opposite the EFK 12. The system 10 comprises the evaluation device 30. The evaluation device 30 is connected to the sensor arrangement 28 for signal transmission from the sensor arrangement 28 to the evaluation device 30.

[0088] The sensor arrangement 28 transmits, for example, a continuous signal to the evaluation device 30, for example in real time or as a periodic signal with a transmission frequency of at least 20 Hz. The sensor arrangement 28 is arranged and configured to generate corresponding output signals 34 depending on at least one feature 32 of the EFK 12, which output signals 34 are evaluated by the evaluation device 30 (cf. Figs. 4A to 4D). The sensor arrangement 28 is configured to generate corresponding output signals 34 depending on at least one feature of the EFK 12 and to send them to the evaluation device 30. The feature 32 of the EFK 12 occurs periodically during the displacement, in particular movement, of the EFK 12 relative to the sensor arrangement 28, in particular in a repetitive manner corresponding to the chain pitch of the EFK 12. The feature 32 of the EFK 12 is a feature 32 which occurs on each chain link 26 of the EFK 12, in particular at the same location on each of the chain links 26.The feature 32 of the EFK 12 can be repeatedly detected periodically, in particular in accordance with the chain pitch of the EFK 12, during the movement, in particular during the movement, of the EFK 12 relative to the sensor arrangement 28. For example, the feature 32 of the EFK 12 is designed as a respective sub-element of the chain links 26. The feature 32 of the EFK 12 is designed here, for example, as a transverse web 36 on the chain links 26. The sensor arrangement 28 is designed to monitor the EFK 12, in particular the feature 32 of the EFK 12, preferably each chain link 26 of the EFK 12, during the movement of the EFK 12. The sensor arrangement 28 has three sensors 38, 39, 40, which are designed to detect the feature 32 of the EFK 12 during the movement of the EFK 12. Sensors 38, 39, and 40 are designed as capacitive proximity sensors. The sensors 38, 39, and 40 of sensor array 28 are all functionally identical and structurally identical.

[0089] The evaluation device 30 is designed to determine a distance 42 between two chain links 26 of the EFK 12 from the output signals 34 that the evaluation device 30 receives from the sensor arrangement 28 (see Fig. 4A-4D). The evaluation device 30 is designed to determine an instantaneous speed, for example of individual chain links 26 of the EFK 12, from the output signals 34 that the evaluation device 30 receives from the sensor arrangement 28. The evaluation device 30 is designed to normalize the determined distances 42 between each two chain links 26 using determined instantaneous speeds of the chain links 26. The evaluation device 30 is designed to determine a wear state of the EFK 12, in particular of the chain links of the EFK 12, from determined, in particular standardized, distances 42 of the chain links 26 of the EFK 12.The evaluation device 30 can additionally be configured to determine a change in the instantaneous speed of the chain links 26 of the EFK 12 from the output signals 34 that the evaluation device 30 receives from the sensor arrangement 28. D The evaluation device 30 can additionally be configured to determine a wear condition of the EFK 12, in particular of the chain links of the EFK 12, from the determined changes in the instantaneous speed of the chain links 26 of the EFK 12.

[0090] The sensor arrangement 28 comprises a plurality of sensors 38, 39, 40 spaced apart from one another in the direction of travel 15 of the EFK 12, in particular along the longitudinal axis 14 of the EFK 12, and is arranged such that each of the sensors 38, 39, 40 detects the presence of passing transverse webs 36, in particular as the at least one feature 32 of the EFK 12, of the EFK 12 and outputs a corresponding output signal 34.

[0091] The sensor arrangement 28 comprises three sensors 38, 39, 40, which are arranged spaced apart from one another in the direction of travel 15 of the EFK 12, in particular along the longitudinal axis 14 of the EFK 12. In particular, two of the sensors are arranged partially offset from one another in the direction of travel 15 of the EFK 12, and one of the sensors is arranged completely offset from the others in the direction of travel 15 of the EFK 12. The direction of travel 15 of the EFK 12 is aligned parallel to the longitudinal axis 14 of the EFK 12.

[0092] Each of the sensors 38, 38, 40 detects the presence of the feature 32, for example passing crossbars 36, of the EFK 12. Each of the sensors 38, 38, 40 outputs an output signal 34 corresponding to the detected presence or absence of the feature 32, for example the passing crossbar 36, of the EFK 12 (cf. Fig. 4A-4D).

[0093] At least two sensors 38, 39, 40 are provided and / or two sensors 38, 39, 40 are arranged at a distance corresponding to the nominal chain pitch, in particular with respect to a new chain pitch (cf. Fig. 3, 4A-4D). The sensor arrangement 28 has at least two sensors 38, 40, which are offset from one another along the travel direction 15, in particular along the longitudinal axis 14 of the EFK 12, at a distance 44 corresponding to the nominal chain pitch, in particular with respect to a new chain pitch. For one sensor 40 of the three sensors 38, 39, 40, different connection interfaces are provided on the sensor arrangement, depending on which type of energy chain the sensor arrangement 28 is intended to monitor. The three sensors 38, 39, 40 are arranged offset from one another in such a way that when the EFK moves over the sensor arrangement 28, one sensor always generates an output signal which differs from the base signal.Here, the base signal is exemplified as "0" and the output signal as "1." Here, the signal, in particular the output signal, of sensors 38, 39, 40 is exemplified as binary.

[0094] The system 10 has, for example, the EFK 12 for indirect wear detection on the EFK 12. Geometric centers of two sensors 38, 40 are arranged offset from one another along the travel direction 15, in particular along the longitudinal axis 14 of the EFK 12, at a distance 44 corresponding to the nominal chain pitch, in particular with respect to a new chain pitch (cf. Fig. 4A- 4D).

[0095] The sensor arrangement 28 is arranged stationary next to the fixed point 16 in the direction of travel 15 of the EFK 12. The sensor arrangement 28 is stationary connected to the support structure, in particular to a rail unit 46 (see Fig. 2). The sensor arrangement 28 is arranged stationary next to the fixed point 16 for monitoring the upper run 25 of the EFK 12 in the direction of travel 15 of the EFK 12. The stationary fixed point 16 of the EFK 12 is arranged on the lower run 21 of the EFK 12. The sensor arrangement 28 is arranged offset from the stationary fixed point 16 in the direction of travel 15 of the EFK 12, in particular along the longitudinal axis 14 of the EFK 12. The rail unit 46 has two rails aligned parallel to the longitudinal axis 14 of the EFK 12, on which the EFK 12 is mounted and to which the sensor arrangement 28 is connected. The stationary fixed point 16 of the EFK 12 is connected to the rail unit 46 along a longitudinal axis 47 of the rail unit, offset from the sensor arrangement 28.

[0096] The evaluation device 30 is designed to detect, in particular to determine, the temporal behavior of the output signals 34 of the sensor arrangement 28, in particular of individual sensors 38, 39, 40, and / or to detect, in particular to determine, the instantaneous speed of individual chain links 26 from the output signals 34.

[0097] The evaluation device 30 is designed to determine the wear status of a connection between the two chain links 26 from the distances 42, particularly in combination with the instantaneous speeds, of two adjacent chain links 26. The evaluation device 30 is designed to evaluate the output signals 34 of the sensor arrangement 28 for deviations from a pre-stored behavior of a new EFK 12. The evaluation device 30 has a memory module on which data with reference values ​​corresponding to a new EFK 12 are stored, particularly pre-stored.The evaluation device 30 is designed to determine the distance 42 between successive chain links 26 by measuring time intervals between the detection of the periodic feature 32 and a respectively detected instantaneous speed, and preferably to compare it with a predetermined, nominal chain pitch for the purpose of wear detection. The evaluation device 30 is designed to determine the standardized distance 42 between successive chain links 26 by measuring time intervals between the detection of the periodic feature 32 and a respectively detected instantaneous speed. The evaluation device 30 is designed to compare each determined, and in particular standardized, distance 42 with a predetermined, nominal chain pitch for wear detection on the corresponding chain links 26.

[0098] The evaluation device 30 is designed to output a maintenance recommendation based on the evaluation, in particular as a function of a currently detected distance 42 between periodic features 32. The evaluation device 30 has an output module 48, which is designed as an optical and acoustic output module 48. The output module 48 is designed partly as a display and partly as a loudspeaker. The maintenance recommendation is designed partly as an acoustic alarm tone. The maintenance recommendation is designed partly as a visual alarm signal.

[0099] The sensor arrangement 28 and the evaluation device 30 are designed to detect a plurality of consecutive chain links 26 for section-by-section wear detection. The sensor arrangement 28 is designed to continuously monitor the EFK 12 during a movement of the EFK 12, in particular to detect at least one feature 32 of the chain links 26.

[0100] FIG.5 shows a schematic illustration of an exemplary sequence of the method 50 for indirect wear detection on an EFK 12.

[0101] The method 50 has as its essential step a single continuous method step 52. For the sake of simplicity of explanation, method steps that are repeated simultaneously and repetitively or permanently in the continuous method step 52 are explained below as two individual sub-steps in an example sequence.

[0102] In one method step, in particular a detection step 54, the sensor arrangement 28 monitors the EFK 12 moving past the sensor arrangement 28. In one method step, in particular the detection step 54, the sensor arrangement 28 generates an output signal 34 each time the feature 32 on a chain link 26 is detected. In one method step, in particular a detection step 54, each generated output signal is sent to the evaluation device 30. In one method step, in particular a detection step 54, a continuous output signal 34 is sent to the evaluation device 30, which assumes a defined value, for example "1," depending on the presence of the feature 32 and otherwise assumes a base value, for example "0." In one method step, in particular a detection step 54, capacitive proximity sensors are used as the sensors 38, 39, 40 of the sensor arrangement 28.In one method step, in particular a detection step 54, each sensor 38, 39, 40 of the sensor arrangement 28 detects the presence of passing transverse webs 36, in particular as feature 32, of the EFK 12 and outputs a corresponding output signal 34. In one method step, in particular a detection step 54, at least two sensors 38, 39, 40 of the sensor arrangement 28 are used and / or two sensors 38, 39, 40 of the sensor arrangement 28 are used, which are arranged at a distance 44 corresponding to the nominal (as new) chain pitch. In one.

[0103] In the method step, in particular a detection step 54, the sensor arrangement 28 is used, which is arranged stationary next to the fixed point 16 in the direction of travel 15 of the EFK 12.

[0104] In one method step, in particular an evaluation step 56, the evaluation device 30 records the temporal behavior of the output signals 34 of the sensor arrangement 28, in particular of individual sensors 38, 39, 40, and / or the evaluation device 30 determines the instantaneous speed of individual chain links 26 from the output signals 34. In one method step, in particular the evaluation step 56, the evaluation device 30 determines the instantaneous speed of individual chain links 26 from the temporal behavior of the output signals 34, in particular of individual sensors 38, 39, 40, of the sensor arrangement 28.In one method step, in particular an evaluation step 56, the evaluation device 30 determines the distances 42, in particular speed-normalized, between individual chain links 26 from the output signals 34, and in particular from the temporal behavior of the output signals 34, in particular of individual sensors 38, 39, 40, of the sensor arrangement 28. In one method step, in particular an evaluation step 56, the evaluation device 30 evaluates the output signals 34 of the sensor arrangement 28 for deviations from a pre-stored behavior of a new EFK 12. In one method step, in particular an evaluation step 56, the evaluation device 30 compares at least one, preferably speed-normalized, distance 42 between individual chain links 26 with pre-stored distances 44 of a new EFK 12.In one method step, in particular an evaluation step 56, the evaluation device 30 determines the distance 42 between successive chain links 26 by measuring time intervals between the detection of the periodic characteristic 32 and based on a respectively detected instantaneous speed, and in particular compares it with a predetermined, nominal chain pitch for the purpose of wear detection. In one method step, in particular an evaluation step 56, the evaluation device 30 issues a maintenance recommendation based on the evaluation, in particular as a function of a currently detected distance 42 between periodic characteristics 42.

[0105] In a method step, in particular an evaluation step 56, a plurality of successive chain links 26 are detected by the sensor arrangement 28 and evaluation device 30 for section-by-section wear detection.

[0106] In a method step, in particular the continuous repetition step 52, the sensor arrangement 28 generates corresponding output signals depending on the at least one feature that occurs periodically during the movement, in particular the planned movement, of the EFK 12 relative to the sensor arrangement 28, in particular according to the chain pitch of the EFK 12, and is in particular detectable, which are evaluated by the evaluation device 30. List of reference symbols

[0107] 10 systems

[0108] 11 Basis s

[0109] 12 Energy chain (EFK)

[0110] 13 End

[0111] 14 Longitudinal axis

[0112] 15 Travel direction

[0113] 16 fixed point

[0114] 17 End

[0115] 18 carriers

[0116] 20 area

[0117] 21 Lower strand

[0118] 22 Area

[0119] 23 deflection bends

[0120] 24 area

[0121] 25 upper run

[0122] 26 chain links

[0123] 28 Sensor arrangement

[0124] 30 Evaluation device

[0125] 32 feature

[0126] 34 Output signal

[0127] 36 Crossbar

[0128] 38 Sensor

[0129] 39 Sensor

[0130] 40 sensors

[0131] 42 distance

[0132] 44 distance

[0133] 46 rail unit

[0134] 48 Output module

[0135] 50 procedures

[0136] 52 duration

[0137] 54 Capture step

[0138] 56 Evaluation step

Claims

Method and system for the indirect detection of wear in a sliding energy chain Patent claims 1. System (10) for indirect wear detection on an energy chain (12) , for guiding at least one line (19) , such as a cable, hose or the like ., between a stationary fixed point (16) and a relative movable carrier (18) , wherein the energy chain (12) is movable, forming a stationary lower run (21) , a movable upper run (25) and a deflection arc (23) in between , and the energy chain (12) is in particular designed and arranged with a sliding upper run (25), the system (10) comprising a preferably stationary sensor arrangement (28) and an evaluation unit (30) which is connected to the sensor arrangement (28) via a signal connection, characterized in that the sensor arrangement (28) comprises at least two sensors (38, 39, 40) which are each arranged and configured such that the sensors (38, 39, 40) periodically, in particular according to the chain pitch of the energy chain (12), repeatably depending on at least one feature which, when the energy chain (12) is moved relative to the sensor arrangement (28), occurs oris detectable, to generate corresponding output signals (34) which the evaluation unit (30) evaluates and that the evaluation unit (30) is set up to determine the temporal behavior of the output signals (34) of the individual. Sensors (38, 39, 40) to detect and evaluate. System (10) according to claim 1, wherein the sensors (38, 39, 40) are spaced apart from each other in the direction of travel (15) and are arranged and configured such that each of the sensors (38, 39, 40) detects the presence of passing crossbars (36) of the energy chain (12) and outputs a corresponding output signal (34). System (10) according to claim 2, wherein the sensors (38, 39, 40) are designed as capacitive proximity sensors. System (10) according to claim 2 or 3, wherein at least two sensors (38, 39, 40) of the sensor arrangement (28) are arranged at a distance corresponding to the nominal (new) chain pitch and / or are arranged and configured to detect a feature that depends on the chain pitch. System (10) according to claim 2, 3 or 4, wherein the sensor arrangement (28) is arranged stationary next to the fixed point in the direction of travel (15) of the energy chain (12).System (10) according to any one of claims 1 to 5, wherein the evaluation device (30) detects the instantaneous velocity of individual chain links (26) from the temporal behavior of the output signals (34); and / or wherein the evaluation device (30) comprises three sensors (38, 39, 40), wherein two sensors of the sensor arrangement (28) are arranged at a distance corresponding to the nominal chain pitch and a third sensor is provided for direction of travel detection. System (10) according to any one of claims 1 to 6, in particular according to claim 6, wherein the evaluation device (30) evaluates the output signals (34) of the sensor arrangement (28) for deviations from a pre-stored behavior of a new energy chain (12). System (10) according to any one of claims 1 to 7, wherein the evaluation unit (30) determines the distance (42) between successive chain links (26) by measuring time intervals between the detection of the periodic feature (32) and based on a respective instantaneous velocity, and preferably compares it with a predetermined, nominal chain pitch for wear detection. System (10) according to claim 8, wherein the evaluation unit (30) outputs a maintenance recommendation depending on the evaluation, in particular as a function of a currently detected distance between periodic features (32). System (10) according to any one of claims 1 to 9, wherein the sensor arrangement (28) and evaluation unit (30) detect a plurality of successive chain links (26) for section-wise wear detection. Method (50) for indirect wear detection on an energy chain (12) for guiding at least one cable (19), such as, for example,a cable, hose or the like., between a stationary fixed point (16) and a relative movable carrier (18) , wherein the energy chain (12) is movable, forming a stationary lower run (21) , a movable upper run (25) and a deflection arc (23) in between , and the energy chain (12) is in particular designed and arranged with a sliding upper run (25), wherein a preferably stationary sensor arrangement (28) is provided and an evaluation device (30) is provided, which is connected to the sensor arrangement (28) via a signal, characterized in that the sensor arrangement (28) comprises at least two sensors (38, 39, 40), each of which is arranged and configured such that the sensors (38, 39, 40) are periodically, in particular according to the chain pitch of the energy chain (12) , depending on at least one feature which, when the energy chain (12) is moved relative to the sensor arrangement (28), recurring, generate corresponding output signals (34), - that in at least one process step, the sensor arrangement (28) generates corresponding output signals (34) depending on at least one such feature (32) which occurs periodically or can be detected during the process of the energy chain (32) relative to the sensor arrangement (28), in particular according to the chain pitch of the energy chain (12), which are evaluated by the evaluation device (30) and - that the evaluation device (30) detects and evaluates the temporal behavior of the output signals (34) of the individual sensors (38, 39, 40). Method (50) according to claim 11, wherein the sensors (38, 39, 40) are arranged spaced apart from each other in the direction of travel (15) and, in at least one method step, the presence of passing crossbars (36), in particular as the at least one feature (32) of the energy chain (12), is detected by each sensor (38, 39, 40) of the sensor arrangement (28) and a corresponding output signal (34) is output. Method (50) according to claim 12, wherein, in at least one method step, capacitive proximity sensors are used as the sensors (38, 39, 40) of the sensor arrangement (28).Method (50) according to claim 12 or 13, wherein the at least two sensors (38, 39, 40) of the sensor arrangement (28) detect a feature that depends on the chain pitch and preferably a third sensor is provided whose output signal is used for direction of travel detection. Method (50) according to claim 12, 13 or 14, wherein the sensor arrangement (28) is arranged stationary next to the fixed point (16) in the direction of travel (15) of the energy chain (12). Method (50) according to any one of claims 11 to 15, wherein in. In at least one process step, the evaluation device (30) determines the instantaneous velocity of individual chain links (26) from the temporal behavior of the output signals (34) of individual sensors (38, 39, 40). Method (50) according to one of claims 11 to 16, in particular according to claim 13, wherein in at least one process step the evaluation device (30) evaluates the output signals (34) of the sensor arrangement (28), in particular of individual sensors (38, 39, 40), for deviations from a pre-stored behavior of a new energy chain (12).Method (50) according to any one of claims 11 to 17, wherein in at least one method step the evaluation device (30) determines the distance (42) between successive chain links (26) by measuring time intervals between the detection of the periodic feature (32) and based on a respective instantaneous velocity, and preferably compares it with a predetermined, nominal chain pitch for the purpose of wear detection. Method (50) according to claim 18, wherein in at least one method step the evaluation device (30) issues a maintenance recommendation depending on the evaluation, in particular as a function of a currently detected distance (42) between periodic features.Method (50) according to one of claims 11 to 19, wherein in at least one method step a plurality of successive chain links (26) are detected by sensor arrangement (28) and evaluation device (30) for section-wise wear detection.