EP4077192B1 - Elevator system with multiple different support means - Google Patents

Description

The present invention relates to an elevator system.

A cabin of an elevator system and its counterweight are connected by suspension elements.

A support means can be elongated and bendable transversely to its longitudinal direction. For example, a support means can be a rope, a belt, a strap or similar. Each support means can have a large number of support strands. For example, a rope-like support means can be composed of several support strands in the form of strands, usually steel strands. A belt-like support means can have several support strands that are accommodated in a matrix material.

On the one hand, the support means can be designed to hold the weight of the cabin and the counterweight. On the other hand, the support means can be moved by traction with a traction sheave driven by a drive machine in order to be able to move the cabin and the counterweight along travel paths. The support means can therefore also be referred to as support-traction means.

The suspension elements can all be of the same type and have the same physical properties. Using the same suspension elements can optimize the costs of the elevator system, as materials can be easily procured and stored. Furthermore, the same suspension elements have essentially identical service lives, which means that any necessary maintenance or replacement of the suspension elements can be easily planned.

The EP 3 099 854 B1 describes a rope connection. Document US2014/353089 A1 discloses a device according to the preamble of claim 1.

Among other things, there may be a need for an improved elevator system.

Such a need can be met by an elevator system with at least one cabin according to the independent claim. Advantageous embodiments are defined in the dependent claims.

According to one aspect of the invention, an elevator installation according to claim 1 is proposed.

Possible features and advantages of embodiments of the invention may be considered to be based, among other things and without limiting the invention, on ideas and findings described below.

An elevator system can be a passenger transport system for transporting people. A rail system of the elevator system can be arranged in a vertical elevator shaft of a building. At least one cabin of the elevator system and at least one counterweight per cabin can be guided by the rail system so that they can move in the vertical direction. Support means of the elevator system can run essentially parallel to the rail system. The support means can be deflected by 180° at an upper end of the rail system. The support means are designed to transfer a weight of the cabin and the counterweight to the rail system or the building. The support means can also be deflected at the cabin and/or the counterweight.

A support means can be a rope or a belt or strap. A rope can be made up of several strands. A strand can consist of a large number of filaments and/or wires. The strands can be laid in a direction opposite to that of the rope. A belt can have several strands or cords embedded next to each other. The strands or cords can be embedded in a matrix material of the belt. The belt or strap can be designed as a smooth belt. The belt or strap can alternatively be designed as a belt with a profile on a surface, for example as a V-ribbed belt. The strands or cords can transfer the load acting on the suspension element along a longitudinal direction of the suspension element.

A physical property of a support element can reflect or influence various properties and/or functionalities of the support element. For example, such a physical property can influence a vibration behavior of the individual support element. The physical property can also influence a load-bearing capacity of the individual support element. The physical property can influence a fracture mechanism or a failure mechanism of the individual support element. The physical property can also represent or influence an elongation behavior, a bending behavior, a weight, a material composition, a surface structure or other properties of the support element. In a broad sense, a physical property of a support element can also reflect or influence its chemical reactivity or other chemical properties. The physical properties of the various support elements can differ significantly from one another, i.e., for example, by more than 10%, preferably more than 20%, more than 50% or even more than 100%.

The support elements are designed redundantly with regard to the maximum load-bearing capacity that can be carried in the elevator system. One of the support elements alone has a load-bearing capacity or load-bearing force that is sufficient to securely connect the car and the counterweight without the other support element and to hold the loads that occur during normal operation of the elevator system. If one of the support elements fails, damage to the other support element can be prevented by arranging the support elements mechanically independently of one another, for example. The support elements can be attached separately to the car, for example. The support elements can also each have a separate guide or deflection. The support elements can be attached separately to the counterweight.

One of the load-bearing elements has a greater safety reserve than the other load-bearing element. A safety reserve, as a minimum, which must be maintained by load-bearing elements in an elevator system can be specified by safety standards or regulations such as the European standard EN81. A safety reserve can be represented by a safety factor. The safety factor can express how much the load-bearing element is oversized in relation to an expected load. One of the load-bearing elements has a higher safety factor than the other load-bearing element. If one of the load-bearing elements breaks, there is a very high probability that the load-bearing element with the smaller safety reserve will be affected. Since the other load-bearing element is very unlikely to be affected, the cabin can be safely stopped and evacuated. The elevator system can therefore be safely taken out of service. Due to the given probability of failure, the load-bearing element with the smaller safety reserve in particular can be monitored for damage. The elevator system can be monitored in a targeted manner using the specified probability of damage.

The elevator system has two counterweights. One of the support means is connected to one counterweight. The other support means is connected to the other counterweight. By designing the counterweights twice, the support means can be arranged spatially separated from one another. One counterweight can be arranged on a first side of the cabin. The other counterweight can be arranged on the other side of the cabin. Each of the counterweights can be connected to at least one support means on the roof of the cabin. The support means thus run essentially in a vertical direction within an elevator shaft of the elevator system. The support means run within the elevator shaft essentially parallel to a rail system for guiding the cabin and the counterweight in the vertical direction. During operation, the counterweights thus move in the opposite direction to the cabin. Each of the counterweights can possibly be held by at least two support means, whereby the support means can have different physical properties.

The suspension elements can be part of different suspension element arrangements. One of the suspension element arrangements can have a larger number of suspension elements than the other suspension element arrangement. The suspension element arrangements can be composed of several essentially parallel suspension elements. In the case of suspension elements in the form of ropes, the suspension element arrangements can consist of several individual ropes. The different physical properties can be set by different numbers of individual ropes. In the case of suspension elements in the form of belts, the Suspension arrangements have different numbers of straps. If the suspension arrangements have the same safety factors, one suspension arrangement can have a smaller number of suspension elements, each with a larger individual load capacity, while the other suspension arrangement can have a larger number of suspension elements, each with a smaller individual load capacity.

One of the suspension elements can have larger dimensions than the other suspension element. Ropes can have different rope diameters. Belts can have different belt widths and/or belt thicknesses. Different dimensions can cause the suspension elements to have different maximum load-bearing capacities. Different dimensions can cause the suspension elements to have different failure mechanisms. Different failure mechanisms can make it very unlikely that both suspension elements will fail at the same time.

The support elements can have different vibration properties. The different vibration properties can be achieved by different internal structures. Due to the different internal structures, the support elements can have different resonance frequencies. Due to the different internal structures, the support elements can have different failure mechanisms.

For example, the suspension elements can have a different number of strands for the same load. The strands can have different stiffness. Furthermore, the strands can differ in terms of their material, thickness and/or other physical properties. As a result, the resonance frequency of one suspension element can be higher than the resonance frequency of the other suspension element.

Ropes can have different lay directions. Different lay directions can cause excitation in different excitation planes. This can cancel out vibrations. In particular, ropes can have different lay lengths. For example, a different lay length leads to different excitation frequencies at the same unwinding speed due to contact points between the rope and the roller, since the Contact points have different distances due to the different stroke lengths. The different excitation frequencies can lead to a smooth running of the cabin or a low noise level in the cabin through vibration dampening. The cabin can therefore be moved at high speeds.

Ropes can also have different cores. A rope with a fiber core or a core made of synthetic fibers can have a lower density than a rope with a conventional metal core or a metal core. This means that the resonance frequency of one rope can be higher than the resonance frequency of the other rope. The different resonance frequencies can prevent a build-up to a common resonant oscillation.

The load-bearing elements can consist of different materials or material combinations. Different materials or material combinations can lead to different chemical failure mechanisms.

For example, one material or combination of materials can be damaged by an unexpectedly occurring substance, while the other material or combination of materials is not attacked by the substance. The safety of the elevator system can be improved through different chemical failure mechanisms. Likewise, the different materials or different combinations of materials can lead to different vibration behavior of the suspension elements. The different materials or combinations of materials can influence the density and/or bending behavior of the suspension elements and thus lead to different resonance frequencies. For example, one suspension element can have strands or cords made of a metal material, while the other suspension element has strands or cords made of a different metal material or a fiber material, such as plastic, glass, Kevlar or carbon.

The support means can have differently shaped cross-sectional areas or be designed as different types of support means. One support means can for example, have at least one belt. The other suspension element can have at least one rope. Belts and ropes have fundamentally different failure mechanisms. This ensures that both suspension elements never fail at the same time.

The support elements can have essentially the same elongation properties. Despite different physical and/or chemical properties, the support elements can be coordinated with one another in such a way that they exhibit an essentially identical increase in length under the same load. In this way, a load on the support elements can be balanced out.

It is noted that some of the possible features and advantages of the invention are described herein with reference to different embodiments.

Embodiments of the invention are described below with reference to the accompanying drawings, wherein neither the drawing nor the description are to be interpreted as limiting the invention.

Fig.1 shows a representation of an elevator system according to an embodiment.

The figure is merely schematic and not to scale. Identical reference symbols denote identical or equivalent features.

Fig.1 shows a highly schematic representation of an elevator system 100 according to an embodiment. The elevator system 100 has a cabin 102 and a counterweight 104 for the cabin 102. The cabin 102 and the counterweight 104 are connected to one another via a first support means 106 and at least one second support means 108. The support means 106, 108 have different physical properties.

In a conventional elevator system, a cabin can be suspended from a large number of standard steel cables. Together, the steel cables can have a safety factor of 12, for example. Traditionally, steel cables with identical strength and performance are used to evenly distribute the load and braking forces. Since all the cables are the same, all the cables can be equally tensioned and together reach a breaking point.

The approach presented here deliberately and conceptually introduces an asymmetry into the system. For example, the safety factor on one side can be set significantly higher than on the other side to ensure that after an expected service life, the weaker side always reaches the breaking point before the stronger side.

The weaker side can be defined as a predetermined breaking point and monitored using simple methods. For example, a break in a rope on the weaker side can be detected by a slack rope contact. When the rope break is detected, a brake on the cabin can be activated and the elevator system can be stopped and deactivated.

Since the second side is designed to be much stronger than the weak side, it can be ruled out that a break in the weak side will also cause a break in the strong side. The elevator system can therefore be safely evacuated and taken out of service until repairs can be carried out.

If the strong side should also break after the weak side has broken while the elevator system is at a standstill, it is at least ensured that the car is empty.

The ropes can alternatively or additionally have different failure mechanisms that cannot occur simultaneously. One side can break, but the elevator system can be safely moved to a safe position using the other side.

Another reason for applying embodiments of the approach presented here is that by using steel cables as a load-bearing element, Excitation frequencies typically arise from the length of the rope lay. If these come into contact with systems in the elevator system that can vibrate in resonance, a common excitation occurs and leads to acoustic and/or vibration annoyances for the elevator users. This can be counteracted by using suspension elements, particularly ropes, with different physical properties. For example, ropes with different numbers of strands can be used to avoid a common excitation frequency. The rope elongation modules and diameters of both rope types can advantageously be selected to be identical.

The support means 106, 108 run essentially in a vertical direction within an elevator shaft of the elevator system 100. The support means 106, 108 run within the elevator shaft essentially parallel to a rail system for guiding the car 104 and the counterweight 104 in the vertical direction. At an upper end of the elevator shaft, the support means 106, 108 are deflected by 180° in order to connect the car 102 and the counterweight 104 to one another. The car 102 and the counterweight 104 are thus moved in opposite directions by the support means 106, 108.

The support means 106, 108 are redundant in terms of their load-bearing capacity. Each support means 106, 108 alone is designed to support a weight of the cabin 102 with passengers and a weight of the counterweight 104 with a safety reserve. If the first support means 106 is damaged, the second support means 108 can safely support and move the cabin 102 and the counterweight 104. The support means 106, 108 are guided via separate guide rollers. However, the support means 106, 108 can also be guided via common guide rollers in order to ensure a synchronous movement of the support means 106, 108.

According to the invention, the first support means 106 has a greater safety reserve than the second support means 108. For example, the first support means 106 has a safety factor of eight, while the second support means 108 has a safety factor of four. The safety factor expresses how many times the respective support means 106, 108 is oversized in relation to a permissible maximum load of the elevator system 100. Together, the support means 106, 108 have a safety factor of 12. Due to the different safety factors it is extremely unlikely that the first support means 106 will fail. The second support means 108, on the other hand, has a much higher probability of failure due to the significantly lower safety factor of four. If one of the support means 106, 108 should fail, it will very likely be the second support means 108. In the embodiment shown here, the second support means 108 in particular can be monitored.

According to the invention, the elevator system 100 has a second counterweight 110. The second counterweight 110 is connected here to the first support means 106.

In one embodiment, the first support means 106 is part of a first support means arrangement 112. The first support means arrangement 112 has six support means 106. The second support means 108 is part of a second support means arrangement 114. The second support means arrangement 114 has four support means 108. The support means 106 of the first support means arrangement 112 all run over common guide rollers. Likewise, the support means 108 of the second support means arrangement 114 run together over common guide rollers. The support means arrangements 112, 114 can have the same load-bearing capacity despite a different number of support means 106, 108.

In one embodiment, the first support element 106 has a larger cross-sectional area than the second support element 108. If the support elements 106, 108 are ropes, the support elements 106, 08 have different rope diameters. If the support elements 106, 108 are belts, the support elements 106, 108 have different belt widths. Due to the different dimensions, the support elements 106, 108 can have different safety factors as well as different vibration properties. For example, the first support element 106 with the larger cross-sectional area can have a lower natural frequency than the second support element 108 with the smaller cross-sectional area. Furthermore, the support elements 106, 108 can have different failure mechanisms due to the different cross-sectional area. For example, the second support element 108 can be more flexible than the first support element 106 with the larger cross-sectional area due to the smaller cross-sectional area. Due to the greater flexibility, the second support element 108 may be less susceptible to fatigue fractures.

In one embodiment, both support means 106, 108 are ropes. The first support means 106 has a first inner structure. The second support means 108 has a second inner structure. The inner structure can influence vibration properties of the support means 106, 108. For example, the first support means 106 has nine strands as the inner structure of the rope, while the second support means has eight strands as the inner structure. Both support means have the same rope diameter and elongation properties.

Alternatively or additionally, the first support means 106 can have a shorter lay length than the second support means 108. The lay length refers to a rope length in which a strand is wrapped completely around the rope or helically around the rope circumference. The different lay lengths result in contact points with the guide rollers that are at different distances from one another. The different distances between the contact points lead to different excitation frequencies of the support means 106, 108 at the same speed of movement. The resulting vibrations are transmitted through the support means 106, 108 to the cabin 102, where they are weakened by destructive interference due to the different excitation frequencies and can even cancel each other out.

In one embodiment, the support means 106, 108 comprise different materials or material combinations. For example, a core of the first support means 106 can consist of a synthetic fiber material and thus have a lower density than a core of the second support means 108 made of a metal material.

The first support means 106 can also have strands made of a lighter material than the strands of the second support means 108. Due to the different densities, the support means 106, 108 have different weights per meter and thus different vibration properties. The lighter first support means 106 can have a higher natural frequency than the heavier second support means 108.

In addition, the different materials can lead to different corrosion properties. Due to the different corrosion properties one of the support elements 106, 108 may be insensitive to a substance, while the other support element 106, 108 is attacked by the substance. The different corrosion properties can lead to different failure mechanisms.

Finally, it should be noted that terms such as "comprising", "including", etc. do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a plurality. Reference signs in the claims are not to be considered as limitations.

Claims (7)

1. Elevator system (100) comprising at least one car (102), wherein at least two support means (106, 108) having different physical properties are arranged between the car (102) and at least one counterweight (104) of the car (102), wherein the elevator system (100) is designed having two counterweights (104, 110), wherein one of the support means (106) is connected to one counterweight (110) and the other support means (108) is connected to the other counterweight (104), wherein the support means (106, 108) are designed to be redundant with regard to a maximum load-bearing capacity to be carried in the elevator system, characterized in that one of the support means (106) has a greater safety reserve than the other support means (108).
2. Elevator system (100) according to any of the preceding claims, wherein the support means (106, 108) are components of different support means arrangements (112, 114), wherein one of the support means arrangements (112) has a greater number of support means (106) than the other support means arrangement (114).
3. Elevator system (100) according to any of the preceding claims, wherein one of the support means (106) has larger dimensions than the other support means (108).
4. Elevator system (100) according to any of the preceding claims, wherein the support means (106, 108) have different vibration properties.
5. Elevator system (100) according to any of the preceding claims, wherein the support means (106, 108) consist of different materials or combinations of materials.
6. Elevator system (100) according to any of the preceding claims, wherein the support means (106, 108) have differently shaped cross-sectional areas.
7. Elevator system (100) according to any of the preceding claims, wherein the support means (106, 108) have the same expansion properties.

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