Method for operating an elevator system in the event of creep deformation of a roller

Abstract

The present invention relates to a method (20) for operating an elevator system (1.1, 1.2) with at least one elevator shaft (2), at least one guide rail (4) arranged in the elevator shaft (2), and at least one car (5) movable along the guide rail (4) with at least one roller (10), wherein the roller (10) rolls along the guide rail (4) to guide the car (5), the method (20) comprising the steps: defining (21) a critical dwell time, wherein a critical creep deformation of the at least one roller (10) is assumed when the car (5) is stationary for the critical dwell time, detecting (22) a dwell time of the car (5), and moving (23) the car (5) along the guide rail (4) to relieve the roller (10) when the critical dwell time is reached by the detected dwell time. The present invention further relates to an elevator system (1.1, 1.2) to carry out such a procedure (20).

Description

Technical area

[0001] The present invention relates to a method for operating an elevator installation having at least one elevator shaft, at least one guide rail arranged in the elevator shaft and at least one elevator car movable along the guide rail and having at least one roller, wherein the roller rolls along the guide rail to guide the elevator car.

[0002] Furthermore, the present invention relates to an elevator installation for carrying out such a method, the elevator installation comprising: at least one elevator shaft, at least one guide rail arranged in the elevator shaft, at least one elevator car movable along the guide rail and at least one control device for controlling the elevator car, wherein the elevator car has at least one roller and the roller rolls on the guide rail to guide the elevator car. Background of the invention

[0003] Elevator systems for the vertical transport of people and / or goods are an integral part of modern residential and commercial buildings. A typical elevator system comprises one or more elevator shafts, each of which houses one or more elevator cars that are moved between landing positions by means of drives such as suspension drives or linear drives.

[0004] In such elevator systems, it is known that a car is guided by rollers on a guide rail, with the rollers rolling along the guide rail as the car moves. The rollers also regularly transmit forces between the car and the guide rail, which compress the rollers. If the car is stationary for an extended period, for example overnight, the forces can cause a creep effect that leads to creep deformation of the roller, which in turn causes the roller to roll unevenly the next time the car moves. Such uneven rolling may be perceived as unpleasant by elevator passengers and, in the worst case, as potential damage to the elevator system.

[0005] DE 10 2014 017 357 A1 discloses a compensation device for elevator cars with decentralized holding force. This device applies a force to the guide rail when the elevator car is stationary, resulting in a compensating torque that largely compensates for uneven loading on multiple guide rollers. This significantly reduces plastic deformation of the guide rollers during standstill, despite the use of soft roller material.

[0006] From US 11,325,809 B2, an elevator system with sensor monitoring on the guide rollers of a car is also known, whereby wear is to be detected by means of the sensor monitoring. Description of the invention

[0007] Based on this situation, it is an object of the present invention to prevent uneven rolling of the roller during operation of the elevator system.

[0008] The object of the invention is achieved by the features of the independent main claims. Advantageous embodiments are specified in the subclaims. Where technically feasible, the teachings of the subclaims can be combined arbitrarily with the teachings of the main and subclaims.

[0009] In particular, the object is accordingly achieved by a method for operating an elevator installation with at least one elevator shaft, at least one guide rail arranged in the elevator shaft and at least one elevator car which can be moved along the guide rail and has at least one running roller, wherein the running roller rolls on the guide rail to guide the elevator car, the method comprising the steps of: defining a critical standstill time, wherein a critical creep deformation of the at least one running roller is assumed when the elevator car is at a standstill for the critical standstill time, detecting a standstill time of the elevator car and moving the elevator car along the guide rail to relieve the load on the running roller when the critical standstill time is reached by the detected standstill time.

[0010] It is preferred that the sequence of process steps can be varied, unless technically required in an explicit order. However, the aforementioned sequence of process steps is particularly preferred.

[0011] Advantageous aspects of the claimed invention are explained below, and preferred modified embodiments of the invention are further described below. Explanations, particularly regarding advantages and definitions of features, are essentially descriptive and preferred, but not limiting, examples. If an explanation is limiting, this will be expressly stated.

[0012] According to the present understanding, an elevator system is designed, for example, with at least one vertical and / or horizontal elevator shaft and at least one car that can be moved in the elevator shaft, but can also have several, in particular several parallel, elevator shafts with further cars.

[0013] For example, an elevator car is held and driven in a vertical elevator shaft by means of a suspension element, with a drive device transmitting a drive torque to the suspension element. The suspension element is further preferably connected to a counterweight associated with the car. A drive device is arranged, in particular, in a machine room above the elevator shaft(s) or in an upper section of an elevator shaft, the so-called shaft head. A suspension element is designed, in particular, as a rope, belt, strap, chain, or the like and carries tensile loads in the direction of its longitudinal extension.

[0014] In a lift car supported by a suspension element, a force transmitted by at least one roller is generated, for example, by a decentralized suspension of the lift car and / or by a variable weight of the suspension element acting on the roller, which varies depending on the extension of the suspension element between the lift car and the drive mechanism, i.e., depending on the lift car position. Such a force can also arise from an uneven distribution of people and / or transported goods in the lift car.

[0015] Alternatively, a car is held and driven by a linear drive. A linear drive in an elevator system, for example, is formed from a primary part extending along the elevator shaft and a secondary part located on the car. The primary part is made up of coils arranged one behind the other in a line, each of which is assigned a converter. Current is supplied to the coil to generate a magnetic field when the car is in the area of ​​the respective coil. The magnetic field is generated in such a way that the car is attracted or repelled by the magnetic field depending on its intended travel path. The secondary part is formed by a permanent magnet or electromagnet that interacts with the magnetic fields of the coil.

[0016] In a car held by a linear drive, a force transmitted through at least one roller is generated, for example, by the linear drive suspending the car only on one side of the car, where the guide rail in the elevator shaft is also located, for example, using a so-called backpack frame. The car's suspension is then subject to a moment load.

[0017] An elevator shaft is a continuous shaft that extends over multiple floors and / or along multiple areas of a building and has a cross-section designed for the passage of the elevator car. An elevator shaft of the elevator system can extend vertically and / or horizontally. In one embodiment, the elevator system has at least one partial section of the elevator shaft in which the shaft extends vertically and at least one partial section in which the elevator shaft extends horizontally, wherein the elevator car can move from the vertically extending section to the horizontally extending section.

[0018] A guide rail is designed, for example, as an I-profile, L-profile, or T-profile, with at least one surface of a profile leg being designed as a guide surface on which the at least one roller rolls. In particular, two opposing surfaces of a profile leg can also be designed as guide surfaces, with several opposing rollers rolling on the respective guide surfaces.

[0019] A roller is, in particular, made of a plastic, in particular a rubber material, at least in a part forming a running surface. However, it is also within the scope of the present disclosure for the roller to be made alternatively of other materials, such as metal or ceramic materials. The selection of the roller depends, for example, on the properties of the elevator system, in particular its nominal speed and / or its elevator shaft extension, or the expected force to be transmitted between the roller and guide rail. The creep behavior of a particular roller is then determined based on the roller material and other properties of the roller, such as its diameter, as well as the force acting on the roller.

[0020] Creep (also known as retardation) refers to the time- and temperature-dependent viscoelastic or plastic deformation of materials under constant load. A key parameter for creep is the creep modulus or creep coefficient. Creep must always be considered in design tasks, for example, in mechanical engineering or construction, and can influence the behavior of the respective objects to a considerable extent. Creep effects affect, for example, all metallic materials, polymers such as plastics or rubber, as well as ceramics, concrete, and wood.

[0021] In plastics consisting of large (or, in the case of thermoplastics and elastomers, also entangled) molecular chains, creep occurs, for example, through sliding or uncoiling of the molecular chains under external load, resulting in elongation. The magnitude of the creep effect or elongation depends, for example, on the manufacturing process, the base polymer, the fillers used, and / or the filler content of the plastic. Various creep effects are known in metallic materials, such as diffusion creep, dislocation creep, dislocation slip, or grain boundary creep / slip.

[0022] A critical service life can be defined empirically, mathematically, and / or through simulation. Critical creep deformation is assumed, for example, if the deformation during the next car movement affects the ride behavior, particularly the unsteady rolling of the roller, to a perceptible and / or disturbing extent. The critical service life can be defined once or, depending on various influences, repeatedly and / or regularly.

[0023] The recording of a downtime duration is most easily done by a central control device of the elevator system, but can also be done using one or more sensors and / or by means of a control device specially set up for this purpose.

[0024] The solution to the problem with the method described above now includes the teaching that creep deformation is usually reversible and resolves itself by relieving the deformation point, in particular by flexing the roller during travel of the elevator car. It is therefore intended to avoid a standstill beyond the critical standstill time by initiating movement of the elevator car when the critical standstill time is reached, so that creep deformation is resolved by relieving the load at the latest when the critical creep deformation is reached. The elevator car is therefore moved without a car call if it remains stationary for too long. The critical standstill time is preferably selected such that creep deformation, which would have a noticeable influence on the travel behavior of the elevator car or the operating behavior of the elevator system, does not occur.This method advantageously prevents the rollers from rolling unevenly during actual operation of the elevator system, i.e., when used by passengers, and thus a negative perception of the elevator system's operating behavior by a passenger due to creep deformation of the roller. In particular, it prevents a passenger from assuming that the elevator system is damaged due to such behavior and triggering a costly inspection of the elevator system.

[0025] The movement of the elevator car to relieve the load on the roller occurs at a rate that depends on the properties of the roller and the elevator system, as well as on the defined critical service life. In principle, the effort required to resolve creep deformation is inversely proportional to the creep behavior of the roller. Therefore, if creep is low, so that it takes a long time for critical creep deformation to occur, a relatively large effort is required to resolve the creep deformation.

[0026] In the simplest case, the elevator car is moved just far enough so that the creep-deformed area of ​​the roller is no longer in contact with the guide rail, and the creep deformation there can subsequently resolve over time due to the elastic properties of the roller. However, a process to relieve the load on the roller is preferably carried out over a longer distance, i.e., at least corresponding to several revolutions of the roller, in order to cause the roller to relieving the creep deformation.

[0027] As an alternative to the features described above, or in a preferred embodiment of the above, it is provided that when the critical standstill time is reached, the elevator car is moved to a new standstill position that differs from the previous standstill position due to the detected standstill time. Regardless of whether the creep deformation has already been resolved upon reaching the new standstill position, a new load is then applied to the roller at a different angular position, so that the previously deformed area of ​​the roller remains unloaded in the new standstill position and the creep deformation and / or remaining microstructural influences associated with the creep deformation can completely recover and / or resolve. In particular, the new standstill position is spaced from the previous standstill position by a distance that is not divisible by the circumference of the at least one roller.This ensures, beyond the already high probability, that the previously deformed area will not be subjected to further deformation.

[0028] As an alternative to the features described above, or in a preferred embodiment of the above, it is provided that, upon reaching the critical stop time, the elevator car is moved several times along the guide rail in a change of direction. This ensures sufficient flexion of the roller to resolve the creep deformation.

[0029] As an alternative to the features described above, or in a preferred embodiment of the above, it is provided that, upon reaching the critical standstill time, the elevator car is moved at a speed below the nominal speed of the elevator system during the detected standstill time. This is based on the principle that slow flexing to relieve the load on the roller, i.e., to resolve the creep deformation, has a greater effect than fast flexing. In particular, the duration for which the force acting between the roller and the guide rail acts on a respective angular position during one revolution of the roller is advantageously increased in order to achieve an effect that counteracts creep deformation.

[0030] As an alternative to the features described above, or in a preferred embodiment of the above, it is provided that the critical service life is determined as a function of properties, in particular material properties, of the at least one roller. In particular, the critical service life is determined as a function of the creep coefficient of the material of a region of the roller forming the running surface of the roller and / or the size of the roller. By selecting the critical service life based on the properties of the roller, a critical service life can advantageously be precisely selected, which reliably prevents critical creep deformations, while also avoiding unnecessarily frequent movement of the elevator car.

[0031] As an alternative to the features described above, or in a preferred embodiment of the above, the critical service life is determined depending on the load-bearing capacity of at least one roller. The load-bearing capacity is understood, for example, to be the expected or actual average or maximum force transmitted between the car and the guide rail via the roller. This varies in particular depending on the type and arrangement of the car's suspension. For example, in a single-sidedly suspended car, significantly greater forces are transmitted by the roller than in a centrally suspended car.By selecting the critical service life based on the load capacity of at least the roller, a critical service life can be advantageously selected with precision, with which critical creep deformations are reliably avoided, while unnecessarily frequent movement of the car is also avoided.

[0032] In a preferred embodiment of the immediately above-described embodiment, the elevator system comprises a car with at least two rollers, wherein the critical service life is determined depending on the load capacity of the most heavily loaded roller. In particular, the car comprises more than two rollers in order to be guided on the guide rail in a rotationally fixed manner in all spatial directions except the direction of travel and / or about all rotation axes.

[0033] As an alternative to the features described above, or in a preferred embodiment of the above, the critical idle time is determined based on usage data of the elevator system. For example, typical usage times of the elevator system can be derived from usage data, with the critical idle time then being selected such that it is shorter than a typical non-use period, for example during the night in an office building. Alternatively, and still purely by way of example, the critical idle time is determined for each daily cycle, starting from the last use in an evening, such that the movement of the elevator car to relieve the load on the roller occurs shortly before the first use the following morning. By taking usage data into account, the method can advantageously be tailored to the individual circumstances of a specific elevator system.In particular, it may also be provided that the definition of the critical downtime after the installation of an elevator system is based on initial usage data, for example through machine learning processes.

[0034] The object is further achieved by an elevator system, comprising: at least one elevator shaft, at least one guide rail arranged in the elevator shaft, at least one elevator car movable along the guide rail, and at least one control device for controlling the elevator car, wherein the elevator car has at least one roller, and the roller rolls along the guide rail to guide the elevator car, and wherein the control device is configured to carry out a previously described method. The advantages described above with regard to the method can be achieved correspondingly with the elevator system. In particular, uneven rolling of the roller during operation is avoided in the elevator system.

[0035] In a preferred embodiment of the immediately above-described embodiment, the elevator system further comprises a drive device and at least one support means, wherein the elevator car is suspended from the support means and the support means is driven by the drive device to move the elevator car. In an elevator system with a support means suspension of the elevator car, a force arises between the elevator car and the guide rail, which leads to an indentation of the at least one roller and thus to creep deformation when the elevator car is stationary, for example due to a decentralized suspension, due to a variable weight distribution in the elevator car, due to different weight forces depending on the unwinding length of the support means (resulting from the position of the elevator car) or due to tolerances. The advantages described above with regard to the method can therefore be achieved orSuch creep deformation is compensated for by the process described above.

[0036] Alternatively, the elevator system has a linear drive, wherein a primary part of the linear drive is arranged along the elevator shaft and a secondary part of the linear drive is arranged on the elevator car, and wherein the elevator car is held and driven by means of the linear drive. In an elevator system with a linear drive of the elevator car, a force arises between the elevator car and the guide rail, which leads to an indentation of at least one roller and thus to creep deformation when the elevator car is stationary, in particular due to a one-sided suspension on the side of the elevator car on which the linear drive is also arranged. The elevator car is then guided on the guide rail under a moment load dependent on its load, which acts on a (respective) roller as a force in the direction of contact of the roller.

[0037] The advantages described above with regard to the method can be achieved with regard to such creep deformation or such creep deformation is compensated for by the method described above.

[0038] As an alternative to features immediately above or in a preferred embodiment of the immediately above, the elevator system further comprises a car frame, wherein the elevator car is received on the car frame and wherein the at least one roller is arranged on the car frame. In an elevator system with support means suspension, the elevator car is preferably suspended via a central frame between two lateral guide rails, with at least one roller being arranged on the elevator car for each guide rail. In an elevator system with a linear drive, the elevator car is preferably suspended via a backpack frame, with at least two pairs of rollers being arranged on the elevator car, and with one roller of each pair of rollers being in front of the guide rail and one roller of each pair of rollers being in front of the guide rail and one roller of each pair of rollers being behind the guide rail. The two pairs of rollers can then absorb any moment load on the guide rail.Regardless of the suspension, preferably so many rollers are arranged on the car, in particular the car is guided on the guide rail in such a way that it can only move in the direction of the guide rail. Short description of the drawings

[0039] The invention will be explained in more detail below with reference to preferred embodiments and the accompanying drawings. The term "figure" is abbreviated to "Fig."

[0040] The drawings show Fig. 1 a highly simplified schematic view of an elevator system according to a preferred embodiment; Fig. 2 a highly simplified schematic view of an elevator installation according to a further preferred embodiment; and Fig. 3 a process diagram of a method according to a preferred embodiment. Detailed description of the drawings

[0041] The described embodiments are merely examples that can be modified and / or supplemented in a variety of ways within the scope of protection defined by the claims. Each feature described for a specific embodiment can be used independently or in combination with other features in any other embodiment. Each feature described for an embodiment of a specific claim category can also be used correspondingly in an embodiment of a different claim category.

[0042] Fig. 1 shows an elevator installation 1.1 in a first embodiment, with an elevator shaft 2 extending in the vertical direction V and guide rails 4 arranged on both sides in the elevator shaft 2 by means of brackets 3. A car 5 is arranged between the guide rails 4, the elevator car 5 being suspended from a support means 6 which is anchored at both ends in a shaft head 2.1 of the elevator shaft 2, is guided via a drive device 7 (shown in a greatly simplified manner), and is connected to a counterweight 8 guided behind the elevator car 5. A plurality of rollers 10 are arranged on the elevator car 5, with which the elevator car 5 is guided along the guide rails 4. In particular, further rollers (not shown) are arranged on the elevator car 5 for guiding the elevator car 5 in the direction of the plane of the drawing, such that the elevator car 5 can only be moved in the vertical direction V.

[0043] In the elevator installation 1.1, a force is generated which acts in a contact direction A of the rollers 10, for example due to a deviation of the center of force of the support means 6 on the elevator car 5 from the center of gravity of the (loaded) elevator car 5. The elevator installation 1.1 has a control device 11 which is only shown in a very simplified manner, wherein the control device 11 is configured with respect to the aforementioned force to carry out the function described with reference to Fig. 3 procedure 20 described below is set up.

[0044] Fig. 2 shows a lift installation 1.2 in a further embodiment, wherein in Fig. 1, already existing elements are designated with the same reference numerals and will not be described again. In the elevator system 1.2, only one guide rail 4 is arranged on a rear wall 2.2 of the elevator shaft 2, opposite the shaft doors 13. The (for example two) elevator cars 5 are each held in a car frame 14 designed as a backpack frame, each of which is formed by a support part 14.1 and a carriage 14.2. A linear drive (not shown in detail) is formed between the carriage 14.2 and the elevator shaft 2. Furthermore, four rollers 10 are arranged on the carriage 14.2, each of which forms pairs of rollers 16 with one roller 10 resting on the guide rail 4 from the front and one roller 10 resting on the rear. The pairs of rollers 16 of a respective carriage 14.2 can support moment loads on the guide rail 4 and are subjected to different forces. In particular, the carriage 14.2 further rollers, not shown, are arranged to guide the car 5 in the direction of the plane of the drawing, so that the car 5 can only be moved in the vertical direction V.

[0045] In the elevator system 1.2, a force is generated which acts in a contact direction A of the rollers 10, by the weight of the elevator car 5, which is introduced into the guide rail 4 via the elevator car frame 14 acting as a lever arm. The elevator system 1.2 has a control device 11 which is only shown in a very simplified manner, wherein the control device 11 is configured with respect to the aforementioned force to carry out the function described with reference to Fig. 3 procedure 20 described below is set up.

[0046] Fig. 3 shows a schematic representation of a method 20 for operating an elevator installation 1.1, 1.2, wherein in a first step 21 a critical standstill time is defined, wherein when the elevator car 5 is at a standstill over the critical standstill time a critical creep deformation of the at least one roller 10 is assumed. The creep deformation occurs in the elevator installations 1.1, 1.2 when the elevator cars 5 are at a standstill, for example, due to the forces described above acting on the rollers 10 in their contact direction A. In a second step 22 a standstill time of the elevator car 5 is recorded, for example by means of the control device 11 and / or by means of Fig. 1 and Fig.2 sensors not shown in detail. In a third step 23, upon reaching the critical standstill time, the elevator car 5 is moved along the guide rail 4 to relieve the load on the roller 10. This allows any creep deformations of the roller 10 to reset and / or be flexed out. In a fourth step 24, the elevator car 5 is stopped and parked in a new position different from the previous position. The angular position of the roller 10 subjected to force in the previous position is preferably relieved. List of reference symbols 1.1 Elevator system 1.2 Elevator system 2 elevator shaft 2.1 Shaft head of the elevator shaft 2.2 Rear wall of the elevator shaft 3 Console 4 guide rail 5 car 6 load-bearing means 7 Drive device 8 Counterweight 10 roller 11 Control device 13 Shaft door 14 car frames 14.1 Supporting part of the car frame 14.2 Car frame carriage 16 pairs of rollers 20 Procedures for operating an elevator system 21 First step - Defining a critical downtime 22 Second step - Recording a downtime 23 Third step - Moving the car to relieve the roller 24 fourth step - stopping and parking the car in the new position A landing direction V vertical direction QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2014 017 357 A1

[0005] US 11,325,809 B2

[0006]

Claims

[1] Method (20) for operating a lift installation (1.1, 1.2) with at least one lift shaft (2), at least one guide rail (4) arranged in the lift shaft (2) and at least one car (5) movable along the guide rail (4) with at least one roller (10), wherein the roller (10) rolls on the guide rail (4) to guide the car (5), the method (20) comprising the steps: Defining (21) a critical service life, wherein when the car (5) is at a standstill over the critical service life, a critical creep deformation of the at least one roller (10) is assumed; Detecting (22) a standstill duration of the car (5); and Movement (23) of the car (5) along the guide rail (4) to relieve the load on the roller (10) when the critical standstill time is reached by the detected standstill time. [2] Method (20) according to claim 1, wherein the car (5) is moved (24) into a new position deviating from the previous position when the critical standstill time is reached by the detected standstill time. [3] Method (20) according to claim 1 or 2, wherein the car (5) is moved several times along the guide rail (4) in a change of direction when the critical standstill time is reached by the detected standstill time. [4] Method (20) according to one of the preceding claims, wherein the car (5) is moved at a speed below a nominal speed of the elevator installation (1.1, 1.2) when the critical standstill time is reached by the detected standstill time. [5] Method (20) according to one of the preceding claims, wherein the critical service life is determined as a function of properties, in particular material properties, of the at least one roller (10). [6] Method (20) according to one of the preceding claims, wherein the critical service life is determined as a function of a load of the at least one roller (10). [7] Method (20) according to claim 6 for operating an elevator installation (1.1, 1.2) with a car (5) with at least two rollers (10), wherein the critical service life is determined as a function of a load of the most highly loaded roller (10). [8] Method (20) according to one of the preceding claims, wherein the critical service life is determined as a function of usage data of the elevator installation (1.1, 1.2). [9] Lift installation (1.1, 1.2), comprising: at least one elevator shaft (2); at least one guide rail (4) arranged in the elevator shaft (2); at least one car (5) movable along the guide rail (4); and at least one control device for controlling the elevator car (5); wherein the car (5) has at least one roller (10) and the roller (10) rolls on the guide rail (4) to guide the car (5); and wherein the control device is configured to carry out a method (20) according to one of the preceding claims. [10] Elevator installation (1.1, 1.2) according to claim 9, further comprising a drive device and at least one support means, wherein the elevator car (5) is suspended from the support means and the support means is driven by means of the drive device for moving the elevator car (5). [11] Elevator installation (1.1, 1.2) according to claim 9, further comprising a linear drive, wherein a primary part of the linear drive is arranged along the elevator shaft (2) and a secondary part of the linear drive is arranged on the elevator car (5), and wherein the elevator car (5) is held and driven by means of the linear drive. [12] Elevator installation (1.1, 1.2) according to one of claims 9 to 11, further comprising a car frame (14), wherein the car (5) is received on the car frame (14) and wherein the at least one roller (10) is arranged on the car frame (14).

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