METHOD AND DEVICE FOR MONITORING PROPERTIES OF A SUPPORTING-MEANS ARRANGEMENT IN AN ELEVATOR SYSTEM

Abstract

A method and a supporting-means monitoring device monitor properties of a supporting arrangement in an elevator system. The supporting arrangement has a plurality of supporting devices that support and can displace an elevator car. The method includes: measuring tensile forces acting on the supporting devices; and deriving change information indicating changes in the properties of the supporting arrangement by analyzing the progression over time of the measured tensile forces. By such an analysis, taking into consideration, for example, a temporal gradient, a frequency spectrum, and/or an amplitude of the progression over time of the measured tensile forces, there is derived e.g. information about wear on a surface profiling or a traction surface of a deflection roller or a traction sheave, information about wear on guide rails and/or information about wear of lateral guide structures on a roller for guiding one of the supporting devices.

Claims

1-14. (canceled)

15. A method for monitoring properties of a supporting-means arrangement in an elevator system, wherein the supporting-means arrangement has a plurality of supporting means by which an elevator car is supported and displaced, the method comprising the steps of: measuring tensile forces acting on the supporting means; deriving change information indicating changes in properties of the supporting-means arrangement by analyzing a progression over time of the measured tensile forces; and determining whether an inspection of the elevator system appears necessary based upon the change information.

16. The method according to claim 15 wherein the change information includes at least one of the following change information items derived from the analysis: information about wear on a surface profiling on at least one circumferential surface of a roller deflecting one of the supporting means and a contact surface of the one supporting means; information about wear on a traction surface on at least one circumferential surface of a traction sheave driving one of the supporting means and a contact surface of the one supporting means; information about wear on a guide component of the elevator car during a displacement of the elevator car along the guide component; and information about wear of lateral guide structures for guiding one of the supporting means while the one supporting means is deflected by a roller when the one supporting means is displaced.

17. The method according to claim 15 including measuring tensile forces acting on each of the individual supporting means and deriving the change information by analyzing the progression over time of the measured tensile forces on the individual supporting means.

18. The method according to claim 17 wherein when the change information is further derived by comparing the progressions over time of the measured tensile forces on the individual supporting means.

19. The method according to claim 15 including deriving the change information by analyzing at least one parameter selected from a group of parameters comprising: a gradient of the progression over time of the measured tensile forces; a frequency spectrum of the progression over time of the measured tensile forces; and an amplitude of the progression over time of the measured tensile forces.

20. The method according to claim 15 including transmitting measured values obtained by measuring the tensile forces to an external evaluation device located remote from the elevator system and operating the evaluation device to derive the change information.

21. The method according to claim 15 including generating a notification signal when the derived change information indicates changes in the properties of the supporting-means arrangement that appear to require an inspection of the supporting-means arrangement.

22. The method according to claim 21 wherein the notification signal contains information related to the derived change information about the changes in the properties of the supporting-means arrangement.

23. A supporting-means monitoring device for monitoring properties of a supporting-means arrangement in an elevator system, wherein the supporting-means arrangement has a plurality of supporting means by which an elevator car is supported and can be displaced, comprising: the supporting-means monitoring device being adapted to execute or control the method according to claim 15 when connected to the elevator system.

24. The supporting-means monitoring device according to claim 23 comprising: at least one sensor for measuring the tensile forces acting on respective ones of the supporting means; an evaluation device receiving the measured tensile forces and deriving the change information indicating the changes in the properties of the supporting-means arrangement by analyzing the progression over time of the measured tensile forces.

25. The supporting-means monitoring device according to claim 24 wherein the evaluation device is arranged external to and remote from the elevator system.

26. The supporting-means monitoring device according to claim 24 including a plurality of sensors for measuring the tensile forces, each of the sensors being integrated in a hitching device for fastening one of the supporting means to a fastening structure in the elevator system.

27. A computer program product comprising non-transitory computer readable instructions that when loaded into a computer instruct the computer to execute or control the method according to claim 15.

28. A non-transitory computer-readable medium having the computer program product according to claim 27 stored thereon.

Description

DESCRIPTION OF THE DRAWINGS

[0058] FIG. 1 shows an elevator system having a supporting-means monitoring device for carrying out a method according to an embodiment of the present invention.

[0059] The figure is merely schematic and is not to scale. The same reference signs indicate the same or equivalent features.

[0060] FIG. 2 is a block diagram of the evaluation device shown in FIG. 1 for implementing or controlling the method according to the present invention.

DETAILED DESCRIPTION

[0061] FIG. 1 shows an elevator system 1 in which an elevator car 5 and a counterweight 7 can be displaced vertically within an elevator shaft 3 using a supporting-means arrangement 9. The supporting-means arrangement 9 has a plurality of supporting means or devices 11 in the form of cables or belts. In the 2:1-type configuration shown, the supporting means 11 are attached with their ends to a ceiling of the elevator shaft 3 via hitching devices 21. Alternatively, in a 1:1-type configuration, the supporting means 11 could also be attached with their ends to the elevator car 5 or the counterweight 7 via a hitching device. The supporting means 11 can be driven via a traction sheave 15 driven by a drive machine 13 and, if necessary, can be deflected via deflection rollers 17, which can be attached to the elevator car 5 and/or to the counterweight 7, among other things. The traction sheave 15 and the deflection rollers 17 can be referred to generically as rollers 16 below. What they have in common is that they interact with one or more of the supporting means 11 of the supporting-means arrangement 9 and generally deflecting their course in the process. Operation of the drive machine 13 can be controlled by an elevator control 19.

[0062] The elevator system 1 shown contains a plurality of sensors 29 by means of which tensile forces acting on the supporting means 11 can be measured. Measurement results can be transmitted by wire or wirelessly to an evaluation device 25 by means of a data transmission device 23 and analyzed there with regard to the progression over time of the measured tensile forces in order to be able to derive desired change information from them. The evaluation device 25 can be part of the elevator system 1. Alternatively, the evaluation device can be provided external to and remote from the elevator system 1. Together with the evaluation device 25, the sensors 29 form a supporting-means monitoring device 27.

[0063] In FIG. 1, two areas having dashed lines are enlarged and depicted rotated 90° to show details of a supporting means 11 interacting with the traction sheave 15 on the one hand and details of a possible design of a hitching device 21 on the other hand.

[0064] In the example shown, the supporting means 11 is designed as a belt. The belt has V-shaped longitudinal grooves on a lower side, which form a surface profiling. The belt hugs a traction surface 47, which is formed by a circumferential surface of the traction sheave 15. The traction surface 47 is also designed with a surface profiling 45 which is essentially complementary to that surface profiling of the belt. The traction sheave 15 has bead-like lateral guide structures 49 at opposite axial edges. The lateral guide structures 49 are formed by regions of the traction sheave 15 having an enlarged radius and steep side flank, so that the supporting means 11 is guided laterally by the two lateral guide structures 49 and is prevented from sliding axially from the traction sheave 15.

[0065] The hitching device 21 serves to attach a plurality of the supporting means 11 contained in a supporting-means arrangement 9 to a fastening structure 39, such as, for example, a ceiling of the elevator shaft 3 in the case shown. For this purpose, the individual supporting means 11 are each accommodated in a loop-like manner in a clamping device 31, in which they are supported in a force-locking manner by a clamping action of a wedge 32. Each of the clamping devices 31 is connected via a rod 33, which extends through a respective opening in the fastening structure 39, to an associated spring 35, via which the tensile force caused by the supporting means 11 is ultimately transmitted to a pressure plate 37. A sensor 29 is provided between each of the pressure plates 37 and the fastening structure 39 by means of which sensor the force exerted by the pressure plate 37 can be measured and, thus, the tensile force exerted by the associated supporting means 11 can be determined.

[0066] As an alternative to the configuration shown in the figure, many other possibilities are conceivable in which the tensile forces acting on the supporting means 11 can be measured using suitably designed and positioned sensors 29. For example, it is conceivable to integrate a force measuring sensor directly into the clamping device 31 provided with the wedge 32, as a result of which, among other things, a number of components could be reduced.

[0067] Using the evaluation device 25, the tensile forces measured by the sensors 29 can be analyzed with regard to their progression over time. In this way, change information can be derived which can contain information about wear on the surface profiling 45 or on the traction surface 47, for example.

[0068] For example, if the surface profiling 45 wears, the supporting means 11 may no longer be correctly guided with respect to the traction sheave 15, but may temporarily move slightly in the axial direction of the traction sheave 15 and the surface profiling of the supporting means 11 is laterally offset with respect to the surface profiling 45 of the traction sheave 15 and runs upwards on it. This can lead to the supporting means 11 apparently being briefly driven by a traction sheave 15 having a larger radius and thus being conveyed at a higher circumferential speed, so that forces on the supporting means 11 temporarily increase. As soon as the supporting means 11 slides back into its correctly guided position with its surface profiling, these forces are reduced again. The increase and subsequent decrease in the tensile forces on the supporting means 11 can be characteristic of the lateral displacement of the supporting means 11 relative to the traction sheave 15 with respect to a gradient, a frequency spectrum and/or an amplitude of the progression over time of the tensile forces, so that by appropriate analysis of these variables the type and/or the extent of wear of the surface profiling 45 can be deduced.

[0069] In a similar manner, wear on the traction surface 47 can be deduced, provided that such wear leads to a reduced frictional force between the traction surface 47 of the traction sheave 15 and the contact surface of the supporting means 11 lying against it, and this reduced frictional force, for example, results in a brief, jerky slipping of the supporting means 11 relative to the traction surface 47. Here, too, analyzed gradients, frequency spectra and/or amplitudes can provide an indication of the type and/or extent of wear of the traction surface 47.

[0070] By suitably analyzing the measured tensile forces on the supporting means 11, cases can also be detected in which, for example, the elevator car 5 is guided using guide components 41 in the form of guide rails 43 and guide shoes (not shown) sliding along them during their vertical movement along the elevator shaft 3 and wear has occurred on the guide components 41. For example, the guide components 41 can show wear in such a way that forces which are exerted on the elevator car 5 are no longer caused uniformly, but rather, for example, jerky forces are induced on the elevator car 5. These are passed on to the supporting means 11 supporting the elevator car 5 and can thus be measured using the sensors 29. An analysis of gradients, frequency spectra and/or amplitudes of the measured tensile forces can also be used in this case to determine the type and/or extent of changes in the properties of the supporting-means arrangement 9 caused by the wear of the guide components 41.

[0071] Furthermore, embodiments of the method described here can also be used to deduce wear on guide structures 49 which, for example, laterally guide the supporting means 11 on the traction sheave 15 and prevent it from slipping off. Wear on these guide structures 49 can result in the supporting means 11 being able to displace itself briefly in the axial direction of the traction sheave 15 and thereby partially run onto the guide structures 49. The resulting apparently increased radius of the traction sheave 15 causes a brief force peak on the supporting means 11 before it slides back to its correct position on the traction surface. A gradient, a frequency spectrum and/or an amplitude of this force peak can be characteristic of the wear on the guide structure 49.

[0072] If it is detected that determined change information indicates a change in properties of the supporting-means arrangement 9 which is so significant that it appears necessary to inspect the elevator system, the evaluation device 25 can output a notification signal. This notification signal can be transmitted, for example, to an external monitoring center or a technician performing the inspection. If necessary, information can be integrated into the notification signal, which includes information about the type and/or the extent of a detected change in the properties of the supporting-means arrangement 9, so that the inspection can be prepared and carried out in a targeted manner.

[0073] The method proposed here and the supporting-means monitoring device 27 provided for its implementation can enable a simplified installation of the supporting-means arrangement 9, a reduced effort in the maintenance of the supporting-means arrangement 9 and/or an increased reliability when monitoring properties of the supporting-means arrangement 9. The method can be implemented or controlled by the evaluation device 25 shown in more detail in FIG. 2. The device 25 also could be a computer or a programmable controller. A computer program product 51, formulated in any desired computer-readable language, can be used to instruct the device 25 in a suitable manner. The device 25 can have the necessary hardware, especially a processor 53 for executing the computer program and processing data relating to the measured tensile forces, a memory 55 for storing the computer program and such data and/or interfaces 23 for entering or outputting such data.

[0074] Finally, it should be noted that terms such as “having,” “comprising,” etc. do not preclude other elements or steps and terms such as “a” or “an” do not preclude a plurality. Furthermore, it should be noted that features or steps that have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above.

[0075] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.