HK1081512B - Elevator - Google Patents

Description

Elevator with a movable elevator car

Technical Field

The present invention relates to an elevator.

Background

One of the goals of elevator development work has historically been to achieve an economical and efficient use of building space. In recent years, this development work has presented, among other things, various solutions for implementing elevators without machine room. Good examples of elevator without machine room are disclosed in e.g. technical specifications EP 0631967 and EP 0631968. The elevators described in these specifications are fairly effective in respect of space utilization as they make it possible to eliminate the space required in the building by the machine room without enlarging the elevator shaft. In the elevators disclosed in these specifications, the machine is compact at least in one direction, while in the other direction it can be much larger than a normal elevator machine.

In these otherwise good examples, however, the space required for the hoisting machine constitutes a limitation for the elevator lay-out. The passage of the hoisting ropes takes up significant space. The space required for the elevator car itself on its path of movement and likewise the space required for the counterweight can hardly be reduced, at least at a reasonable cost and without impairing elevator performance and quality. In traction sheave elevators without machine room, especially in the case of solutions with machine above, it is difficult to install the hoisting machine in the elevator shaft because the machine is heavy and large. Especially the size and weight of the machines designed for larger loads, higher speeds and/or larger hoisting heights are so problematic in respect of installation that the scope of application of the concept of elevator without machine room has even been limited in practice, or at least the introduction of the concept has been abandoned in the case of larger elevators.

Specification WO 99/43589 discloses an elevator suspended on a flat belt, achieving a smaller belt bending diameter on the traction and diverting pulleys. This solution, however, involves problems in that the lay-out solution, the installation of the components in the elevator shaft and the orientation of the structural pulleys are limited. Secondly, the orientation of the polyurethane-coated belts with the supporting steel components, for example in the case of an inclined elevator car, is also problematic. An elevator made in this way must be fairly heavy, at least as far as the machine and/or the components supporting it are concerned, in order to avoid undesired vibrations. In addition, the bulkiness of the remaining elevator components required to keep the diverting and traction sheaves oriented relative to each other also increases the weight and cost of the elevator. Moreover, the task of installing and adjusting such a system is difficult and requires a high degree of precision.

Specification WO 01/68973 discloses an elevator provided with coated hoisting ropes, in which the ropes are twisted from a number of coated strands and finally even externally coated with plastic or similar material. The outer diameter of the rope is specified to be 12mm, which is a very large diameter compared to the invention. A relatively thick rope of this type, which combines steel wire ropes with a thick and soft outer layer, has the problem that the bottom of the steel core turning rope groove sinks in as the rope passes around the drive or diverting sheave, forcing the thick and soft outer sheath to give way aside. The only direction of yielding is upwards along both sides of the groove, and the sheath of the rope thus tends to be squeezed out of the groove. This can result in rapid wear of the rope.

Another expedient for achieving a small bending diameter of the rope is to use rope constructions in which the load-bearing part is made of artificial fibres. An elevator rope of this type, based on a man-made fibre structure, is disclosed in european patent application No. EP 1022376. Although a solution like this does make it possible to obtain ropes that are lighter than steel wire ropes, rayon ropes do not form any substantial advantage, at least in elevators intended for the most common hoisting heights, especially because rayon ropes are considerably more expensive than steel wire ropes. Furthermore, the thermal resistance of artificial fibre ropes, such as in the case of a fire, must not be as good as the corresponding resistance of steel wire ropes.

Disclosure of Invention

The object of the present invention is to overcome the above-mentioned drawbacks and/or to reduce the size and weight of the elevator or at least its machinery by providing the possibility to use traction and diverting sheaves of smaller diameter. The current aim is to achieve a more efficient use of space in buildings.

In order to achieve the above-mentioned object, according to the invention an elevator is provided with coated hoisting ropes, in which elevator a hoisting machine engages a set of hoisting ropes by means of a traction sheave, said set of hoisting ropes comprising coated hoisting ropes of substantially circular cross-section having a load-bearing part twisted from very strong steel wires of circular and/or non-circular cross-section, and in which elevator said set of hoisting ropes supports a counterweight and an elevator car moving on their respective rails, characterized in that each hoisting rope supports a counterweight and an elevator carThe cross-sectional area of the steel wire is more than 0.015mm²And less than 0.2mm²And the strength of the steel wire is more than 2000N/mm²And the core of each hoisting rope, consisting of steel wires, is coated with a relatively thin sheath softer than the core, constituting the surface of the hoisting rope.

Preferably, the sheath of the hoisting rope is made of rather hard rubber, polyurethane or some other non-metallic material having a hardness exceeding shore a 80.

Preferably, the hoisting rope is thin, wherein the core, which constitutes the load-bearing part and consists of steel wires, has a diameter of between 2 and 10mm, and wherein the ratio of the diameter of the steel wire core to the thickness of the sheath is larger than 4.

Preferably, the hoisting rope core consisting of steel wires has a diameter of 4-6mm and the sheath has a thickness of 0.4-0.6 mm.

Preferably the rope grooves of the traction sheave have a semicircular cross-sectional shape.

Preferably the outer diameter of the traction sheave driven by the elevator drive machine is at most 250 mm.

Preferably at least part of the space between the strands and/or wires in the hoisting rope is filled with rubber, urethane or some other medium of a substantially non-fluid nature.

Preferably, the elevator is a machine room-less elevator.

Preferably, the sheath of the hoisting rope is made of some other non-metallic material having a hardness between shore a 80-95.

Preferably, the ratio of the diameter of the steel cord core to the thickness of the sheath is between 6 and 12.

Preferably, the ratio of the diameter of the wire rope core to the thickness of the outer sheath is 8.

Preferably, the sheath (17) has a thickness of 0.5 mm.

The invention makes it possible to obtain, among other things, one or more of the following advantages:

the strong steel used makes it possible to use thin ropes;

the steel core moves less towards the bottom of the rope groove due to the thin and hard surface material, so that the shape of the rope is kept better;

the thin layer of surface material makes it possible to obtain a rope without great differences in the thickness of the layer of filling material, which may make the rope inhomogeneous;

the surface material layer makes it possible to obtain good friction between the rope and the rope groove;

due to the thin elevator ropes, the traction and diverting pulleys are both small and light compared to those in a normal elevator;

a smaller traction sheave makes it possible to use a smaller operating brake in the elevator;

a smaller traction sheave involves a lower torque requirement and therefore the motor and its operating brake can be smaller;

with smaller traction sheaves, for a given elevator car speed to be achieved, higher rotational speeds are required, which means that the same motor power output can be achieved by a smaller motor;

the use of a smaller traction sheave makes it possible to use a smaller elevator drive machine, which means that the acquisition/manufacturing costs of the drive machine are reduced.

The good gripping capacity between the traction sheave and the ropes and the use of parts of small weight make it possible to reduce the weight of the elevator car considerably, and correspondingly also to use a counterweight that is lighter than in prior-art solutions;

the smaller machine size and the thin and substantially round ropes make it possible to arrange the elevator machine relatively freely in the shaft. Thus, the elevator solution can be implemented in a wide variety of ways, both in the case of elevators with machine above and in the case of elevators with machine below;

the weight of the elevator car and counterweight can be borne wholly or at least partially by the elevator guide rails;

in the elevator applying the invention, the central suspension of the elevator car and counterweight can be easily implemented, thus reducing the lateral supporting forces applied to the guide rails;

by applying the invention, the effective utilization of the cross section area of the vertical shaft is realized;

the invention shortens the time required for installing the elevator and reduces the total installation costs;

the light and thin ropes are easy to handle and handle to significantly simplify and speed up the installation process;

the thin and strong steel wire rope of the invention has a diameter of the order of only 3-5mm, such as in the case of an elevator designed for a nominal load below 1000kg and a speed below 2 m/s;

with rope diameters of about 6 to 8mm, a fairly large elevator for higher speeds can be achieved by means of the invention;

the invention can be used in gearless and geared elevator motor solutions;

although the invention is designed primarily for use in elevators without machine room, it can also be used in elevators with machine room.

The main field of application of the invention is elevators designed for transporting people or freight. Another main area of application of the invention is in passenger elevators whose speed range is usually about 1.0m/s or higher, but may also be e.g. only about 0.5 m/s. In the case of a freight elevator, too, the speed is preferably at least about 0.5m/s, although lower speeds may be used in heavy load situations. In the elevator of the invention elevator hoisting ropes twisted from essentially round and strong wires and coated with e.g. polyurethane are used. The circular steel wire is adopted, and the steel wire,the rope can be twisted in many ways using wires of different or equal thickness. In the rope usable in the invention the average wire thickness is below 0.4 mm. Good-suitability ropes made of strong wires are ropes having an average wire thickness below 0.3mm or even below 0.2 mm. For example, strong 4mm ropes of thin wires can be twisted relatively economically from the wires so that the average wire thickness in the finished rope is between 0.15 and 0.25mm, in which case the thinnest wires may even have a thickness of only about 0.1 mm. Thin rope wires can easily be made very strong. The invention employs a composite material having a strength in excess of about 2000N/mm²The rope wires of (1). The proper range of the strength of the steel wire of the rope is 2300-². In principle, it is possible to use a material having a strength of up to about 3000N/mm²Or even higher rope wires.

Drawings

In the following, the invention will be described in detail by means of an embodiment example with reference to the attached drawings, in which

Fig. 1 is a diagonal plan view of a typical elevator solution of the invention in which coated steel wire ropes are employed;

FIG. 2 is a cross-section of a prior art coated wire rope;

fig. 3 is a cross-section of a coated steel wire rope for use in a conforming elevator according to the invention; and

fig. 4 is a longitudinal section of a part of a rope sheave used in the elevator of the invention.

Detailed Description

Fig. 1 presents a typical elevator solution, in which the hoisting ropes 9 used are coated steel wire ropes. The elevator is preferably an elevator without machine room, in which the hoisting machine 3 is connected to hoisting ropes via a traction sheave 5, which is a coated hoisting rope 9 of substantially circular cross-section, arranged side by side and supporting the counterweight 2 and the elevator car 1 moving along their respective paths, i.e. along guide rails 8 and 7. The hoisting ropes 9 arranged side by side are fastened to a fixed starting point 10, from where they run downwards to a diverting pulley 6 essentially below the elevator car, mounted in conjunction with the elevator car 1. From diverting pulley 6 the hoisting ropes go to a similar second diverting pulley at the other lower edge of the elevator car and, having passed around this second diverting pulley, the ropes go upwards to the traction sheave 5 of the elevator drive machine 3 mounted in the upper part of the elevator shaft. Having passed around the traction sheave via the upper edge of the traction sheave 5, the hoisting ropes go again downwards to diverting pulleys 6 connected to the counterweight 2, passing around them along the lower edge of these pulleys and going upwards again to their fixed end point 11. The functions of the elevator are controlled by a control system 4.

Fig. 2 is a prior-art elevator rope 13 coated with polyurethane 15 or equivalent material. The thickness of the polyurethane layer 15 and the cross-sectional deformation of the cord are somewhat exaggerated for clarity. Due to the thickness of the polyurethane layer 15 or equivalent material and its softer mass, the forces acting on the elevator rope tend to press the steel core 14 of the rope towards the bottom of the rope groove of the rope sheave 12. This pressure in turn tends to displace the filling material, as a result of which the filling material moves upwards in the direction of the bottom surface of the rope groove indicated by the arrows and tends to bulge out of the rope groove. This large deformation can produce a strong strain on the rope and is therefore an undesirable situation.

Fig. 3 correspondingly is the hoisting rope 9 of the elevator according to the invention. The core of the rope consists essentially of a number of thin and strong steel wires 16 twisted together in a suitable manner. The figure is not drawn to scale. The covering of the hoisting rope consists of a substantially thin outer sheath 17, which is softer than the core and is made of rubber, polyurethane or some other suitable non-metallic material with sufficiently hard properties and a high friction coefficient. The sheath has a hardness at least exceeding Shore A80(Shore A80), preferably between Shore A88 and 95. The thickness of the sheath has been optimized with respect to durability, but it is still significantly small relative to the diameter of the load carrying core formed by the steel wires 16. A suitable diameter of the steel cord is 2-10mm and the ratio of the cord diameter to the sheath 17 thickness is significantly greater than 4, preferably between 6-12 and suitably for example about 8. A suitable thickness of the steel cord core is between 4-6mm, and in this case the sheath has a thickness substantially between about 0.4-0.6mm, preferably e.g. 0.5 mm. The sheath should preferably have a thickness at least such that, for example, a grit is not immediately worn away when it is clamped between the hoisting rope 9 and the surface of the rope groove 18. In practice, a suitable range of variation of the sheath thickness may be, for example, 0.3-1mm, depending on the thickness of the cord used.

The mutual structure of the sheath 17 and the core is so constructed that the friction between the sheath 17 and the core is greater than the friction between the sheath 17 and the rope grooves 18 of the traction sheave 5. Thus, any undesired slipping that may eventually occur will occur at the intended place, i.e. between the traction sheave and the rope surface instead of inside the hoisting rope between the core and the sheath, or otherwise damage the hoisting rope 9.

Fig. 4 is a cross-sectional view of a portion of the sheave 5 to which the present invention is applied. Each rope groove 18 has a semicircular sectional shape. Since the hoisting ropes 9 used are considerably thinner and stronger than normally, the traction sheave and the other rope pulleys can be designed to have a size considerably smaller than when normally sized ropes are used. This also allows the use of smaller size and lower torque elevator drive motors, which can result in lower motor acquisition costs. For example in the elevator of the invention for nominal loads below 1000kg the traction sheave diameter is preferably 120-200mm, but may even be smaller than this. The diameter of the traction sheave depends on the thickness of the hoisting ropes used. Usually a diameter ratio D/D of 40 is used, where D is the diameter of the traction sheave and D is the thickness of the hoisting ropes. This ratio can be reduced somewhat at the expense of the resistance of the rope to wear. In addition, without compromising the service life, the D/D ratio can be reduced if the number of ropes is increased at the same time, in which case the strain on each rope will be smaller. Such a D/D ratio of less than 40 may be, for example, about 30, or less, such as a D/D ratio of 25. However, reducing the D/D ratio to a value significantly below 30 tends to affect the service life of the rope, essentially reducing it, although this can be compensated by using a special construction of the rope. Achieving a D/D ratio below 20 is difficult in practice, but can be achieved by using a rope specially designed for this purpose, although such a rope is likely to be expensive.

Due to the small traction sheave, in elevators according to the invention for nominal loads of e.g. less than 1000kg, a machine weight as low as about half the weight of the current drive machine can be easily achieved, which means that the elevator machine has a weight as low as 100 and below 150 kg. In the present invention, the machine is considered to comprise at least a traction sheave, a motor, machine housing components and brakes.

It will be easy to obtain an elevator in which the machine without supporting members has a net weight below 1/7, or even 1/10, or even lower than the nominal load. Basically, the ratio of the machine weight to the nominal load is given for a normal elevator in which the counterweight has a weight substantially equal to the weight of the empty car plus half the nominal load. As an example of the weight of the machine in the case of an elevator of a nominal weight when a fairly common 2: 1 suspension ratio is used for a nominal load of 630kg, the combined weight of the machine and its supporting elements may be only 75 when a traction sheave diameter of 160mm and hoisting ropes having a diameter of 4mm are used, in other words the total weight of the machine and its supporting elements is about 1/8 of the nominal load of the elevator. More generally, the thin and strong steel wire rope of the invention has a diameter of 2.5-5mm in elevators for nominal loads below 1000kg, and preferably about 5-8mm in elevators for nominal loads above 1000kg, when a 2: 1 suspension ratio is used. In principle it is possible to use ropes thinner than this, but in this case a larger number of ropes will be needed, unless e.g. the suspension ratio is increased.

The smoothness of the rope can also be improved by using a polyurethane or similar coating. The use of thin wires allows the rope itself to be made thinner, since the thin wire material can be made stronger than thicker wires. E.g. a 4mm thick elevator hoisting rope of fairly good construction can be made using about 0.2mm steel wires. Depending on the thickness of the hoisting ropes used and/or for some other reason the thickness of the steel wires in the steel wire rope may preferably be in the range between 0.15mm and 0.5mm, in which range steel wires with good strength properties are readily available, wherein even a single steel wire has a sufficient wear resistance and a sufficiently low vulnerability.

Above, ropes made of round steel wires have been described. Using the same principle, the rope can be twisted wholly or partly from wires with a non-round profile. In this case, the cross-sectional area of the steel wire is preferably substantially the same as that of a round steel wire, i.e. at 0.015mm²-0.2mm²Within the range of (a). With steel wires within this thickness range, it will be easy to make wires having a thickness of about 2000N/mm²The above steel wire strength and 0.015mm²-0.2mm²And steel wire ropes comprising a steel material cross-sectional area which is large in relation to the rope cross-sectional area, as is obtained for example by using the Warrington construction. For the practice of the invention, it is particularly suitable to have a thickness of 2300N/mm²-2700N/mm²Rope of wire strength within the scope of this invention, because such a rope has a great load-bearing capacity with respect to rope thickness, while the high hardness of the strong wires does not present any substantial difficulties in the use of the rope in elevators.

The coating material chosen for use in steel wire ropes is a material which has good friction characteristics and good wear resistance and which, as mentioned, is very hard. The coating of the steel wire rope can also be carried out such that the coating material penetrates partially into the rope or penetrates through the entire rope thickness.

It is obvious to the person skilled in the art that the invention is not limited to the examples described above, but that it may be varied within the scope of the invention. According to the examples described above, the skilled person can vary the embodiment of the invention, for example by using a suitable coating in the rope grooves.

It is also obvious to the person skilled in the art that the ropes can be twisted in many different ways. Likewise, the average of the wire thicknesses is understood to mean a statistical, geometric or arithmetic mean. To determine the statistical mean, for example, a standard deviation or a gaussian distribution can be used. It is also obvious that the wire thickness in the rope may vary, for example, even by a factor of 3 or more.

It is further obvious to the person skilled in the art that the rope can be designed structurally in many different ways. The sheath may have, for example, a double layer structure comprising an outer layer of slightly softer polyurethane or equivalent having good frictional properties; and an inner layer of harder polyurethane or equivalent.

It is also obvious to the skilled person that the lay-out of the elevator solution used can be varied in many ways other than described above. The elevator drive machine 3 can thus be placed lower than before in the elevator shaft, e.g. so that the hoisting ropes 9 pass around it along the underside of the traction sheave 5. In which case the diverting pulleys can be fixed in place correspondingly in the upper part of the elevator.

Claims (12)

1. Elevator, provided with coated hoisting ropes (9), in which elevator a hoisting machine engages a set of hoisting ropes by means of a traction sheave, said set of hoisting ropes (9) comprising coated hoisting ropes (9) of substantially circular cross-section with load-bearing parts twisted from very strong steel wires (16) of circular and/or non-circular cross-section, and in which elevator said set of hoisting ropes supports a counterweight and an elevator car moving on their respective rails, characterized in that the cross-sectional area of the steel wires (16) of each hoisting rope is larger than 0.015mm²And less than 0.2mm²And a steel wire(16) Strength of greater than 2000N/mm²And the core of each hoisting rope (9) consisting of steel wires (16) is coated with a relatively thin sheath (17) softer than the core, constituting the surface of the hoisting rope.

2. Elevator according to claim 1, characterized in that the sheath (17) of the hoisting rope (9) is made of fairly hard rubber, polyurethane or some other non-metallic material having a hardness exceeding shore a 80.

3. Elevator according to claim 1 or 2, characterized in that the hoisting ropes (9) are thin, in which the core, which constitutes the load-bearing part and consists of steel wires (16), has a diameter between 2 and 10mm, and in which the ratio of the diameter of the steel wire core to the thickness of the sheath (17) is greater than 4.

4. Elevator according to claim 1 or 2, characterized in that the core of the hoisting rope (9) consisting of steel wires (16) has a diameter of 4-6mm and the sheath (17) has a thickness of 0.4-0.6 mm.

5. Elevator according to claim 1 or 2, characterized in that the rope grooves (18) of the traction sheave (5) have a semicircular cross-sectional shape.

6. Elevator according to claim 1 or 2, characterized in that the outer diameter of the traction sheave (5) driven by the elevator drive machine is less than or equal to 250 mm.

7. Elevator according to claim 1 or 2, characterized in that at least part of the spaces between the strands and/or wires (16) in the hoisting ropes is filled with rubber, urethane or some other medium of a substantially non-fluid nature.

8. Elevator according to claim 1, characterized in that the elevator is a machine room-less elevator.

9. Elevator according to claim 2, characterized in that the sheath (17) of the hoisting rope (9) is made of some other non-metallic material having a hardness between shore a 80-95.

10. Elevator according to claim 3, characterized in that the ratio of the diameter of the wire rope core to the thickness of the sheath (17) is between 6 and 12.

11. Elevator according to claim 3, characterized in that the ratio of the diameter of the wire rope core to the thickness of the sheath (17) is 8.

12. Elevator according to claim 4, characterized in that the sheath (17) has a thickness of 0.5 mm.