Method for detecting wear of a cable roller of a cable device

Abstract

In order to reliably detect the wear of the cable roller (4) of the cableway arrangement (1), the distance (A) between the cable sensor (10) and the conveying cable (3) is measured when the cableway arrangement (1) is stationary and the wear of at least one cable roller (4) is inferred from the distance (A) measured when the cableway arrangement (1) is stationary.

Description

[0001] This application is a divisional application of the application with the application date of May 18, 2020, the application number of 202080039300.4 (the international application number is PCT / EP2020 / 063812), and the title of "Method for Detecting Wear of Cable Rollers of a Cableway Device".

[0002] The present invention relates to a method for detecting wear of a cable roller of a cableway device, the cableway device having a conveying cable guided via at least one cable roller and having at least one cable sensor arranged at a known position from the cable roller, and using the at least one cable sensor to detect the distance between the conveying cable and the cable sensor.

[0003] In the case of a cableway device, the conveying cable of the cableway is guided via cable rollers on the path and in the stations. The conveying cable is guided on the cable roller on a rolling surface, usually on a rubber ring with a cable guiding groove. The cable roller, in particular the rubber ring of the cable roller, can be worn during the operation of the cableway (for example, due to the carriages passing back and forth on the conveying cable or due to the asymmetric load of the carriages, also during normal operation due to the pressure of the conveying cable on the rolling surface of the cable roller). However, the conveying cable can also be offset on the cable roller (lateral deviation of the conveying cable from the cable guiding groove of the cable roller), which in the worst case can cause the conveying cable to jump out of the cable roller. Therefore, it is known that in the case of a cableway device, cable position monitoring is provided during operation in the area of the roller set on the cableway support or in the station in order to identify an inadmissible offset of the conveying cable on the cable roller, i.e., a lateral deviation. The cable position monitoring is carried out by means of non-contact sensors (for example, inductive proximity sensors (for example, as in DE 197 52 362 A1), Hall sensors (for example, as in US 5,581,180 A) or eddy current sensors (for example, as in WO 2019 / 038397 A1)). In the case of an inadmissible lateral deviation of the conveying cable, the cableway device is stopped or the conveying speed is reduced. During the operation of the cableway device, of course, both of these are undesirable.

[0004] During operation, the rolling surface of the cable roller (e.g., on a rubber ring) is usually monitored so that worn-out cable rollers can be replaced in a timely manner when necessary, thereby preventing restricted operation or operation interruption. This can be carried out by maintenance personnel at certain inspection intervals through visual inspection or automatically. For example, it is known from DE 197 52362 A1 to detect not only the cable position but also the wear on the rolling surface of the cable roller during operation by means of a non-contact sensor. In addition, it is described in US 5,581,180 A and WO 2019 / 038397 A1 that the wear of the cable roller can also be determined by means of a cable position sensor. For wear detection, the distance between a fixedly installed cable position sensor and the conveyor cable is determined during the operation of the cableway.

[0005] However, the operating conditions of the cableway device are very harsh. During operation, the ambient temperature can fluctuate by more than 10 °C within a day, which can cause thermal expansion (in the sense of getting smaller or larger) of the cable roller. Here, the distance between the conveyor rope and the cable position sensor can change significantly, which has a negative impact on the reliability of the distance measurement. Due to the friction between the conveyor rope and the cable roller or the rolling surface of the cable roller, the cable roller can heat up relative to the environment and especially relative to the sensor during operation, which can also cause a change in the detected distance between the conveyor cable and the cable position sensor. Here, the detected distance can change by several millimeters during operation. The conveyor cable itself is subject to vibrations during operation (e.g., due to the cable roller rolling over the cable clamp of the carriage or due to external influences on the cableway device such as wind), whereby the detected distance between the cable position sensor and the conveyor cable can also change continuously during operation. All of these make it unreliable and difficult to detect the wear of the cable roller by distance measurement using a non-contact sensor during operation.

[0006] Therefore, the object of the present invention is to improve the wear detection of the cable roller of the cableway device, in particular to make it more reliable, and thus to improve the operation of the cableway device, mainly maintenance.

[0007] This task is solved by measuring the distance when the cableway device is stationary and inferring the wear of at least one cable roller from the distance measured at rest. By detecting the wear of the cable roller when the cableway device is stationary, the influence on distance measurement caused by operation can be reduced or even eliminated in a simple manner. It is particularly recognized that it is not necessary to detect the distance during operation, because the wear caused by the distance changes only slowly anyway. Therefore, it is advantageous to detect the distance at rest, because more accurate results are also obtained thereby. In a particularly advantageous embodiment, this also makes it possible to use an existing cable position sensor as a cable sensor for distance detection. Thereby, no additional hardware cost is required. This also makes it possible to replace the cable roller of the cableway device in a timely manner when the wear exceeds a pre-given allowable limit value.

[0008] In order to improve the accuracy of wear detection, it can be stipulated that the temperature of the cable roller is detected and the thermal expansion of the cable roller at the detected temperature is taken into account when detecting the distance. Thereby, the possible temperature-related thermal expansion of the cable roller can be taken into account or compensated. Here, the detection of the distance and thus the detection of the wear can also be related to a specific reference temperature.

[0009] In an advantageous design, the distance is measured over multiple days, preferably every day or every x-th day (where x > 1) or at a pre-given time interval, especially always at the same time point throughout the day. This also makes it possible to detect the time curve of the wear. More knowledge about the cableway device can be obtained from the time curve. For example, in the case where the cable roller wears too fast over a certain period of time, another problem of the cableway device can be inferred.

[0010] Hereinafter, the present invention will be explained Figures 1 to 5 in more detail, Figures 1 to 5 exemplarily, schematically and non-limitingly showing advantageous designs of the present invention. Shown in the drawings are:

[0011] Figure 1 A part of the cableway device is shown,

[0012] Figure 2 A part of the roller set of the cableway device is shown,

[0013] Figure 3 A part of the cable roller of the cableway device is shown,

[0014] Figure 4 The measurement field of a non-contact cable sensor is shown,

[0015] Figure 5 The time curve of the detected wear of the cable pulley is shown.

[0016] In Figure 1FIG. 0 shows a part of a well-known cableway installation 1 having two cableway supports 2. At least one transport cable 3 is guided around or back and forth between two cableway stations (not shown) via cable rollers 4. The cable rollers 4 are rotatably supported, for example, on a roller assembly 5 arranged on the cableway support 2. The roller assembly 5 typically includes a plurality of cable rollers 4 arranged successively in the moving direction of the transport cable 3. The cable roller 4 or a group of cable rollers 4 is also typically arranged on a rocker arm 6 rotatably supported on the roller assembly 5. A plurality of carriages 7 (e.g., gondolas or chairlifts) are clamped to the transport cable 3 in a known manner (e.g., using cable clips releasable in the cableway station, but also using fixed clips). The carriages 7 move in this way on the transport cable 3 between the cableway stations. The plurality of cable rollers 4 via which the transport cable 3 is guided can also be arranged in the cableway station.

[0017] Figure 2 FIG. 4 shows a part of a roller assembly 5 having two cable rollers 4. At least one non-contact cable sensor 10 is arranged on the cableway installation 1 (e.g., arranged on the roller assembly 5). The non-contact cable sensor 10 is preferably arranged at a known, defined position relative to the cable roller 4, in particular at a defined distance A from the transport cable 3. When the non-contact cable sensor 10 is arranged on the rocker arm 6 as in Figure 2 FIG. 6, the non-contact cable sensor 10 is preferably arranged at a defined position on the rocker arm 6 relative to the cable roller 4. If the cable roller 4 is rotatably supported in a fixed manner on the roller assembly 5 (i.e., not on the rocker arm 6), the non-contact cable sensor 10 is preferably arranged at a defined position relative to the cable roller 4 of the roller assembly 5. However, a plurality of non-contact cable sensors 10 can also be provided on the roller assembly 5, for example, in the outer end region of the roller assembly 5 as seen in the transport direction X of the transport cable 3. However, it should be noted that the cable roller 4 and the non-contact cable sensor 10 can also be rotatably supported on another fixed part of the cableway installation 1, for example, in the cableway station or in the entry or exit area of the cableway station or on another component of the cableway support 2. The plurality of cable sensors 10 are typically distributedly arranged on the cableway installation 1.

[0018] The non-contact cable sensor 10 can be an inductive or capacitive sensor, for example, an inductive or capacitive proximity sensor, a Hall sensor or an eddy current sensor. Preferably, the non-contact cable sensor 10 also serves as a cable position sensor for detecting a lateral deviation of the transport cable 3 in the lateral direction Y (transverse to the transport direction X) on the cable roller 4. In this case, preferably, the non-contact cable sensor 10 also aligns the cable roller 4 at a defined lateral position. However, it is also conceivable to provide a separate cable position sensor 13 (or a plurality of cable position sensors 13), as shown in Figure 2 FIG. 11.

[0019] The contactless cable sensor 10 is connected to an analysis unit 11 (hardware and / or software) for analyzing the sensor values detected by the contactless cable sensor, as will be described in detail below. It can be stipulated here that each contactless cable sensor 10 is connected to its own analysis unit 11, or a plurality of contactless cable sensors 10 (for example, one (or two) cable sensors 10 in the conveying direction X of the cableway support 2) are each connected to the analysis unit 11. At least one analysis unit 11 is connected to the cableway controller 12 (hardware and software), which can be done wirelessly or wired. The cableway controller 12 is usually arranged in the cableway station. The analysis unit 11 can also be integrated into the cableway controller 12. If a separate cable position sensor 13 is used, the analysis unit 11 can also be connected to the cable position sensor 13 at the same time to detect the cable position of the conveying cable 3 in the lateral direction Y. However, a separate analysis unit for the cable position sensor 13 can also be provided. The analysis unit 11 can also be integrated into the cable sensor 10 or the cable position sensor 13.

[0020] Figure 3 The cable roller 4 is shown in detail. The cable roller 4 generally mainly consists of a central roller body ( Figure 3 not visible in the figure), which is rotatably supported by means of a rolling bearing or other bearing on a central bushing ( Figure 3 not visible in the figure). The cable roller 4 on the cableway device 1 can be arranged on the bushing. Of course, the bushing can also be omitted, and the cable roller can be directly rotatably supported on the bearing at the cableway device 1. The rubber washer 20 can be arranged on the roller body between two laterally arranged flange washers 21. The rubber washer 20 forms the rolling surface 22 of the cable roller 4, and a rope groove 23 in the form of a depression for guiding the conveying cable 3 can be provided therein. The rubber washer 20 is usually arranged to be replaceable. Of course, the roller body itself can also form the rolling surface 22 of the cable roller 4 and / or the flange washer 21. During the operation of the cableway device 1, it is possible that the conveying cable 3 deflects laterally from the rope groove 23 in the lateral direction Y, as Figure 3 shown by the dashed line in the figure. Such a deflection S in the lateral direction Y can be detected by the cable position sensor 13 during the operation of the cableway device 1.

[0021] From Figure 3It can also be seen that as the rolling surface 22 of the cable roller 4 continues to wear, the conveyor cable 3 penetrates deeper and deeper into the rolling surface 22 of the cable roller 4, and thus the conveyor cable 3 travels in the direction of the axis of rotation 14 of the cable roller 4. For safety reasons, only a certain degree of wear of the cable roller 4 is allowed. With increasing wear, the depression V of the rope groove 23 increases. In the case of excessive wear, the cable roller 4 or the rubber washer 20, or generally the part of the cable roller 4 that forms the rolling surface 22, must be replaced.

[0022] The non-contact cable sensor 10 is arranged at a known position relative to the cable roller 4 in order to obtain the distance A between the conveyor cable 3 and the cable sensor 10 (in the direction Z perpendicular to the conveying direction X and the transverse direction Y). Preferably, the cable sensor 10 is arranged at a defined position relative to the unworn cable roller 4 in order to have a defined reference position. However, the reference position can also be determined differently. If the wear increases and thus the depression V increases, the distance A decreases. Thus, when the distance A is measured using the non-contact cable sensor 10, the wear of the rolling surface 22 of the cable roller 4 in the form of an increasing depression V can be detected.

[0023] Generally, the sensor value W detected by the cable sensor 10 is converted into the distance A (or equivalently into the depression V) in the analysis unit 11. Generally, the distance A is the shortest distance between the cable sensor 10 and the conveyor cable (usually in the direction Z).

[0024] In order to reduce or preferably completely eliminate the influence of the operation of the cableway device 1 on the distance measurement, according to the present invention, only the distance A measured when the cableway device 1 is at rest is used for wear detection. Thus, the distance A is measured in the case of the stationary conveyor cable 3. In the case of the stationary conveyor cable 3, it can be assumed that the conveyor cable 3 is located in the rope groove 23 of the cable roller 4 and the conveyor cable 3 does not vibrate or only vibrates slightly.

[0025] Furthermore, by measuring the distance A when the cableway device 1 is at rest, the temperature influence on the measurement of the distance A can be reduced, ideally even eliminated. When at rest, no friction is generated between the conveyor cable 3 and the cable roller 4, and thus the cable roller 4 does not undergo additional thermal expansion due to frictional heat, which makes the measurement of the distance A more accurate. Thus, the cable roller 4 and the cable sensor 10 have substantially the same temperature (substantially the ambient temperature), as long as the cable sensor 10 is not subject to excessive self-heating caused by the built-in electronic device or does not receive different solar radiation (e.g., due to shading), and thus there is no measurement interference due to the temperature difference between the cable roller 4 and the cable sensor 10.

[0026] It is also possible to measure the temperature present when measuring the distance A (for example, by means of a temperature sensor in the cable sensor 10 or near the cable roller 4), and the measured distance A is corrected to a predetermined reference temperature (for example, 21 °C). Thereby, it is possible to compensate, for example, for possible thermal expansion caused by solar radiation. For this purpose, the measured temperature can be used to determine the thermal expansion of the cable roller 4 (for example, by means of a stored table, a mathematical model or a formula), and the temperature-dependent expansion of the cable roller 4 (which changes the distance A) is taken into account when determining the distance A.

[0027] Preferably, the distance A is always measured at the same point in time throughout the day, for example, before the cableway installation 1 starts operating in the morning, preferably before sunrise or shortly after sunrise, or after the cableway installation 1 stops operating in the evening, preferably after sunset or shortly before sunset. If the measurement is carried out after the stop of operation, the measurement preferably waits for a certain fixed time (for example, one hour) so that the cable roller 4 can cool down to the ambient temperature. However, since solar radiation can also cause thermal expansion of the cable roller 4, it is preferably measured at night (such as between sunset and sunrise). It is also possible to determine any point in time between the stop of operation and the start of operation for the measurement of the distance A, for example, always measure at midnight. Since wear only slowly manifests itself as an increase in the indentation V and the measurement resolution of the cable sensor 10 is also limited, it is sufficient to measure the distance A and the associated indentation V not every day but at larger time intervals (for example, weekly or every x-th day throughout the day (where x > 1)).

[0028] However, the measurement of the distance A when the cableway installation 1 is at rest also enables the use of a conventional non-contact cable position sensor 13 as the cable sensor 10 in a particularly advantageous manner, and this non-contact cable position sensor 13 is already installed in today's cableway installations 1. In particular, a non-contact cable position sensor 13 that is particularly simply constructed can be used as the cable sensor 10. Due to the measurement principle, this non-contact cable position sensor 13 cannot identify whether the conveyor cable 3 is moving to the left or to the right (i.e., in the lateral direction) or is moving towards the axis of rotation 14 of the cable roller 4 in the direction Z due to wear.

[0029] An example of such a non-contact cable position sensor 13 is an inductive proximity sensor. The inductive proximity sensor measures the distance to the measurement object without contact by means of an induced voltage. For example, the sensor coil of the sensor fed with alternating current forms an electromagnetic field around the sensor coil. If a conductive measurement object (here the conveying cable 3) enters this electromagnetic field, eddy currents are induced in the measurement object, and the electromagnetic field of these eddy currents cancels the electromagnetic field generated by the sensor coil, thereby changing the impedance of the sensor coil. This change has a defined relationship with the distance of the measurement object, and is analyzed accordingly (e.g., electronically or after digital conversion by the corresponding software). Of course, other measurement principles can also be used.

[0030] In Figure 4 an exemplary family of measurement characteristic curves of the non-contact cable sensor 10 (e.g., an inductive proximity sensor) is shown, which shows the curve of a constant sensor value W with respect to the position of the measurement object (in the transverse direction Y and the direction Z) relative to the cable sensor 10. Here, the position of the measurement object is given starting from the zero position Y = 0 (e.g., the position of the rope groove 23) to the left (negative Y) and to the right (positive Y) and as the distance between the cable sensor 10 and the measurement object (conveying cable 3) in the direction Z. It can be seen from the family of measurement characteristic curves that each detected sensor value W can be understood as a deviation to the left, to the right, or in the direction Z, so that the specific position of the measurement object with respect to the cable sensor 10 cannot be inferred from the sensor value W. However, with such a cable sensor 10, a distinction can be made between the transverse direction Y and the direction Z, because the lateral deflection of the conveying cable 3 in the transverse direction Y increases the distance of the conveying cable 3 to the cable sensor 10, while wear reduces the distance of the conveying cable to the cable sensor 10. Therefore, starting from a known reference position, the deflection in the transverse direction Y and the wear in the direction Z can be identified by an increase or decrease in the detected sensor value. For example, when the conveying cable 3 deflects in the transverse direction Y, the sensor value decreases, and when the conveying cable 3 wears in the direction Z (i.e., when the conveying cable 3 approaches the cable sensor 10), the sensor value increases. Thus, the detected sensor value W of the cable sensor 10 can be uniquely assigned to the lateral deviation of the conveying cable 3 in the transverse direction Y or the change in the distance A in the direction Z.

[0031] When using other measurement principles, the same or similar relationships can also be obtained. However, in principle, sensors can also be used that can distinguish between lateral deviations and distance changes due to the measurement principle or the analysis of the sensor value W. Since such sensors are more costly and thus more expensive, these sensors are generally not used in the cableway installation 1, especially since in the cableway installation 1, a plurality of cable sensors 10 are usually required (usually at least two such cable sensors 10 on each cableway support in each direction of the conveyor cable 3, which already requires 80 sensors in the case of 20 cableway supports).

[0032] For the cable sensor 10, when measuring at rest, it can be assumed that the conveyor cable 3 is located in the cable groove 23 of the cable roller 4. Thus, the sensor value W measured at rest can be assigned to the distance A between the cable sensor 10 and the conveyor cable 3 in any case, completely independently of the type of cable sensor 10.

[0033] Since the cable sensor 10 is usually arranged in the conveying direction X away from the cable roller 4, in the case of the known arrangement and geometry of the cable roller 4 and the cable sensor 10, the detected sensor value W can be converted to the distance A (or equivalently the depression V) or the wear value associated therewith to improve the accuracy.

[0034] Of course, only the wear of the cable roller 4 arranged close enough to the known position of the cable sensor 10 can be reliably detected using the cable sensor 10. The farther the cable roller 4 is arranged from the cable sensor 10, the less precise the detection of the wear will be. Due to the known arrangement and geometry of the cable roller 4 in the area of the cableway installation 1 (for example, on the roller set 5 or the rocker arm 6), the sensor value W detected by the cable sensor 10 in the area of the arrangement of the cable roller 4 can be completely converted to the wear of the plurality of cable rollers 4 in this arrangement.

[0035] To improve the accuracy, the sensor values W of various cable sensors 10 can also be analyzed to determine the wear of the cable roller 4 (for example, the value of the depression V). For example, the sensor values W of various cable sensors 10 can be used to determine the wear of the cable roller 4 and then averaged. Here, weights can also be considered during averaging, which evaluate the distance between the cable sensor 10 and the cable roller 4.

[0036] For example, in Figure 5 the time curves K1, K2 of the increase in the depression V for two cable rollers 4 with respect to the time periods T1 to Tn (for example, a time period covering 3 months) are shown. Starting from the depression V at the time point T1, the depression V continuously increases until the end of the time period at Tn.

[0037] It can be seen that, although the measurement is carried out when the cableway device 1 is stationary, the detected depression V may still be subject to fluctuations, which can be attributed to external influences or to measurement inaccuracies. To compensate for these fluctuations, the wear trend can also be approximated by a regression line (represented by a dashed line in Figure 5 ) or another regression, so that the wear value can be determined at each time point, especially between measurements.

[0038] The limit value V for the permitted wear can be pre-specified, for example, in the form of the maximum permitted depression V G (in the form of a percentage or an absolute value). If the wear of the cable roller 4 reaches the limit value V G , a report can be output by the analysis unit 11 or the cableway controller 12 to indicate the necessary replacement of the cable roller 4 or the roller rubber 20 of the cable roller 4. The report can also be sent to a remote location (for example, to a maintenance center that coordinates its maintenance) via a suitable communication line.

Claims

1. A method for detecting wear of at least one cable roller (4) of a cableway device (1), the cableway device (1) having a conveying cable (3) guided in a cable groove (23) along a conveying direction (X) via the at least one cable roller (4), the cable groove (23) being provided in a rolling surface (22) of the at least one cable roller (4) in the form of a recess (V), characterized in that, The cable sensor (10) is arranged at a defined distance (A) from the conveying cable (3) at a known position from the unworn cable sheave (4) so as to have a reference position of the conveying cable (3) in the rope groove (23) from the cable sensor (10), wherein with increasing wear of the cable sheave (4), the depression (V) of the rope groove (23) increases in the direction (Z) of the axis of rotation (14) of the cable sheave (4) and thereby changes the distance (A), wherein the actual distance (A) between the conveying cable (3) and the cable sensor (10) is detected by means of the cable sensor (10), wherein the detected sensor value (W) of the cable sensor (10) is converted into the actual distance (A) by means of the known position of the cable sensor (10) from the unworn cable sheave (4) and the reference position of the conveying cable (3) from the cable sensor (10), wherein starting from the known reference position, an increase or decrease in the sensor value (W) detected by means of the cable sensor (10) is used to detect a deflection (S) of the conveying cable (3) in a transverse direction (Y) transverse to the conveying direction (X) and an increasing wear of the cable sheave (4) in the direction (Z) of the axis of rotation (14) of the cable sheave (4), wherein the actual distance (A) is detected in the case of a stationary conveying cable (3) when the cableway installation (1) is stationary and wherein the actual value of the depression (V) of the rope groove (23) is inferred from the distance (A) measured at rest as the wear of the at least one cable sheave (4).

2. The method according to claim 1, characterized in that, Detect the temperature of the cable sheave (4) and take into account the thermal expansion of the cable sheave (4) at the detected temperature when detecting the distance (A).

3. The method according to claim 1, characterized in that Use the cable sensor (10) to detect the wear of at least one further cable sheave (4).

4. The method according to claim 1, wherein Use a further cable sensor (10) to detect the wear of the at least one cable sheave (4) and average the wear detected by different cable sensors (10) to obtain the wear of the at least one cable sheave (4).

5. The method according to claim 1, characterized in that Measure the distance (A) over multiple days or daily or every x-th day, where x > 1, or at a pre-given time interval.

6. The method according to claim 5, wherein Always measure the distance (A) at the same time of day.

7. The method according to claim 5, wherein Detect the time profile of the wear.

8. Use of a method according to any one of claims 1 to 7 for operating a cableway installation (1), wherein the cable sheave (4) of the cableway installation (1) is replaced when the wear exceeds a pre-given permitted limit value (VG).

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