Method and device for monitoring properties of a supporting-means arrangement in an elevator system
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.
1 . 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 during operating conditions of the elevator system;
deriving change information indicating changes in properties of the supporting-means arrangement by analyzing a progression over time of the measured tensile forces by analyzing at least one parameter selected from a group of parameters consisting of 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; and
determining whether an inspection of the elevator system appears necessary based upon the change information.
2 . The method according to claim 1 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.
3 . The method according to claim 1 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.
4 . The method according to claim 3 wherein when the change information is further derived by comparing the progressions over time of the measured tensile forces on the individual supporting means.
5 . The method according to claim 1 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.
6 . The method according to claim 1 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.
7 . The method according to claim 6 wherein the notification signal contains information related to the derived change information about the changes in the properties of the supporting-means arrangement.
8 . 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 1 when connected to the elevator system.
9 . The supporting-means monitoring device according to claim 8 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.
10 . The supporting-means monitoring device according to claim 9 wherein the evaluation device is arranged external to and remote from the elevator system.
11 . The supporting-means monitoring device according to claim 9 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.
12 . 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 1 .
13 . A non-transitory computer-readable medium having the computer program product according to claim 12 stored thereon.