The present invention relates to an elevator as defined in the preamble of claim 1.
One of the objectives in elevator development work is to achieve efficient and economical utilization of building space. In recent years, this development work has produced various elevator solutions without machine room, among other things. Good examples of elevators without machine room are disclosed in specifications EP 0 631 967 (A1) and EP 0 631 968. The elevators described in these specifications are fairly efficient in respect of space utilization as they have made it possible to eliminate the space required by the elevator machine room in the building without a need to enlarge the elevator shaft. In the elevators disclosed in these specifications, the machine is compact at least in one direction, but in other directions it may have much larger dimensions than a conventional elevator machine.
In these basically good elevator solutions, the space required by the hoisting machine limits the freedom of choice in elevator lay-out solutions. Space is needed for the arrangements required for the passage of the hoisting ropes. It is difficult to reduce the space required by the elevator car itself on its track and likewise the space required by the counterweight, at least at a reasonable cost and without impairing elevator performance and operational quality. In a traction sheave elevator without machine room, mounting the hoisting machine in the elevator shaft is often difficult, especially in a solution with machine above, because the hoisting machine is a sizeable body of considerable weight. Especially in the case of larger loads, speeds and/or hoisting heights, the size and weight of the machine are a problem regarding installation, even so much so that the required machine size and weight have in practice limited the sphere of application of the concept of elevator without machine room or at least retarded the introduction of said concept in larger elevators. In modernization of elevators, the space available in the elevator shaft often limits the area of application of the concept of elevator without machine room. In many cases, especially when hydraulic elevators are to be modernized or replaced, it is not practical to apply the concept of roped elevator without machine room due to insufficient space in the shaft, especially in a case where the hydraulic elevator solution to be modernized/replaced has no counterweight. A disadvantage with elevators provided with a counterweight is the cost of the counterweight and the space it requires in the shaft. Drum elevators, which are nowadays rarely used, have the drawbacks of heavy and complex hoisting machines with a high power/torque requirement. Prior-art elevator solutions without counterweight are exotic, and no adequate solutions are known. Before, it has not been technically or economically reasonable to make elevators without a counterweight. One solution of this type is disclosed in specification WO9806655. A recent elevator solution without counterweight presents a viable solution. In prior-art elevator solutions without counterweight, the tensioning of the hoisting rope is implemented using a weight or spring, and this is not an attractive approach to implementing the tensioning of the hoisting rope. Another problem with elevator solutions without counterweight, when long ropes are used e.g. due to a large hoisting height or a large rope length required by high suspension ratios, is the compensation of the elongation of the ropes and the fact that, due to rope elongation, the friction between the traction sheave and the hoisting ropes is insufficient for the operation of the elevator. In a hydraulic elevator, especially a hydraulic elevator with lifting force applied from below, the shaft efficiency, in other words the ratio of the cross-sectional shaft area occupied by the elevator car to the total cross-sectional area of the elevator shaft, is fairly high. This has traditionally been a significant factor contributing towards the choice of a hydraulic elevator as the elevator solution for a building. On the other hand, hydraulic elevators have many drawbacks associated with their lifting mechanism and oil consumption. Hydraulic elevators consume plenty of energy, possible oil leakages from the elevator equipment is an environmental risk, the required periodic oil changes constitute a large cost item, even an elevator installation in good repair produces unpleasant smell as small amounts of oil escape into the elevator shaft or machine room and from there further into other parts of the building and into the environment and so on. Because of the shaft efficiency of the hydraulic elevator, its modernization by replacement with another type of elevator that would obviate the drawbacks of a hydraulic elevator while necessarily involving the use of a smaller elevator car is not an attractive solution to the owner of the elevator. Also, the small machine spaces of hydraulic elevators, which may be located at a large distance from the elevator shaft, make it difficult to change the elevator type.
There are a very large number of traction sheave elevators installed and in use. Such traction sheave elevators were built in their time in accordance with the users' needs as conceived at the time and the intended uses of the buildings in question. Afterwards, both users' needs and the uses of the buildings have changed in many cases, and an old traction sheave elevator may have proved to be insufficient in respect of car size or otherwise. For example, older and relatively small elevators are not necessarily suited for the transportation of prams or wheelchairs. On the other hand, in older buildings which have been converted from residential use for office or other uses, a smaller elevator installed in its time is no longer sufficient in respect of capacity. As is known, enlarging such a traction sheave elevator is practically impossible because the elevator car and the counterweight already take up the cross-sectional area of the elevator shaft and there is no reasonable way of enlarging the car.
The object of the invention in general is to achieve at least one of the following objectives. On the one hand, it is an aim the invention to develop the elevator without machine room further so as to allow more effective space utilization in the building and elevator shaft than before. This means that the elevator must be so constructed that it can be installed in a fairly narrow elevator shaft if necessary. One objective is to achieve an elevator in which the hoisting rope has a good grip/contact on the traction sheave. Yet another objective is to achieve an elevator solution without counterweight without compromising the properties of the elevator. A further objective is to eliminate the adverse effects of rope elongations. Another object of the invention is to enable the bottom and top spaces of the elevator shaft to be more effectively utilized by elevators without counterweight.
The object of the invention should be achieved without compromising the possibility of varying the basic elevator layout.
The elevator of the invention is characterized by what is disclosed in the characterization part of claim 1. Other embodiments of the invention are characterized by what is disclosed in the other claims. Inventive embodiments are also discussed in the description section of the present application. The inventive content of the application can also be defined differently than in the claims below. The inventive content may also consist of several separate inventions, especially if the invention is considered in the light of expressions or implicit sub-tasks or from the point of view of advantages or categories of advantages achieved. Therefore, some of the attributes contained in the claims below may be superfluous from the point of view of separate inventive concepts.
By applying the invention, one or more of the following advantages, among others, can be achieved:
The primary area of application of the invention is elevators designed for the transportation of people and/or freight. A typical area of application of the invention is in elevators whose speed range is about 1.0 m/s or below but may also be higher. For example, an elevator having a traveling speed of 0.6 m/s is easy to implement according to the invention.
In the elevator of the invention, normal elevator hoisting ropes, such as generally used steel wire ropes, are applicable. In the elevator, it is possible to use ropes made of artificial materials and ropes in which the load-bearing part is made of artificial fiber, such as e.g. so-called “aramid ropes”, which have recently been proposed for use in elevators. Applicable solutions also include steel-reinforced flat ropes, especially because they allow a small deflection radius. Particularly well applicable in the elevator of the invention are elevator hoisting ropes twisted e.g. from round and strong wires. From round wires, the rope can be twisted in many ways using wires of different or equal thickness. In ropes well applicable in the invention, the wire thickness is below 0.4 mm on an average. Well applicable ropes made from strong wires are those in which the average wire thickness is below 0.3 mm or even below 0.2 mm. For instance, thin-wired and strong 4 mm ropes can be twisted relatively economically from wires such that the mean wire thickness in the finished rope is in the range of 0.15 . . . 0.25 mm, while the thinnest wires may have a thickness as small as only about 0.1 mm. Thin rope wires can easily be made very strong. In the invention, rope wires having a strength greater than about 2000 N/mm2 can be used. A suitable range of rope wire strength is 2300-2700 N/mm2. In principle, it is possible to use rope wires having a strength of up to about 3000 N/mm2 or even more.
By increasing the contact angle by means of a rope sheave serving as a diverting pulley, the grip-between the traction sheave and the hoisting ropes can be increased. A contact angle exceeding 180° between the traction sheave and the hoisting rope is achieved by utilizing a diverting pulley or diverting pulleys. In this way, the weight as well as the size on the elevator car can be reduced, thereby increasing the space saving potential of the elevator.
The elevator of the invention is traction sheave elevator without counterweight, in which elevator the elevator car is guided by elevator guide rails and suspended by means of diverting pulleys on hoisting ropes in such manner that the elevator has rope portions of the hoisting ropes going upwards and downwards from the elevator car. The elevator comprises a number of diverting pulleys in the upper and lower parts of the elevator shaft. The elevator has a drive machine placed in the elevator shaft and provided with a traction sheave. The elevator comprises a compensating device acting on the hoisting ropes for equalizing and/or compensating the rope tension and/or rope elongation. Diverting pulleys are mounted on the elevator car near two side walls. In the elevator of the invention, the rope portions from the diverting pulleys in the lower part of the elevator shaft and the rope portions from the diverting pulleys in the upper part of the elevator shaft to the diverting pulleys mounted on the elevator car extend in a substantially vertical direction. In the elevator, the rope portions connecting the rope portions from one side of the elevator car to its other side are rope portions between the diverting pulleys mounted near different side walls on the elevator car.
In the following, the invention will be described in detail by the aid of a few embodiment examples with reference to the attached drawings, wherein
In
A preferred embodiment of the elevator of the invention is an elevator without machine room and with machine above, in which the drive machine has a coated traction sheave, and which elevator has thin hoisting ropes of a substantially round cross-section. In the elevator, the contact angle between the hoisting ropes and the traction sheave is greater than 1800. The elevator comprises a unit which comprises—fitted in place via a supporting element—a drive machine, a traction sheave and a diverting pulley fitted at a correct angle relative to the traction sheave. The unit is secured to the elevator guide rails. The elevator is implemented without counterweight with a suspension ratio of 6:1. Compensation of rope forces and elongations is implemented using a compensating device according to the invention. The diverting pulleys in the elevator shaft are fitted in place via supporting elements on the elevator guide rails, while the diverting pulleys on the elevator car are all mounted in place on a beam comprised in the elevator car, said beam also forming a structure supporting the elevator car.
It is obvious to the person skilled in the art that different embodiments of the invention are not limited to the examples described above, but that they may be varied within the scope of the claims presented below. For instance, the number of times the hoisting ropes are passed between the upper part of the elevator shaft and the elevator car and between the elevator car and the diverting pulleys below it is not a very decisive question as regards the basic advantages of the invention, although it is possible to achieve some additional advantages by using multiple rope passages. In general, especially applications without counter-weight are so implemented that the ropes go to the elevator car from above as many times as from below, so that the suspension ratios of diverting pulleys going upwards and diverting pulleys going downwards are the same. It is obvious to the skilled person that an embodiment of the invention can also be implemented with odd suspension ratios above and below the elevator car, in which case the compensating device is mounted on the elevator car or its structures. In accordance with the examples described above, the skilled person can vary the embodiment of the invention, while the traction sheaves and rope pulleys, instead of being coated metal pulleys, may also be uncoated metal pulleys or uncoated pulleys made of some other material suited to the purpose.
It is further obvious to the person skilled in the art that the traction sheaves and rope pulleys of metallic or some other appropriate material that are used in the invention, functioning as diverting pulleys and coated with a non-metallic material at least in the area of their grooves, may have a coating made of e.g. rubber, polyurethane or some other material suited to the purpose. It is also obvious to the skilled person that moving the compensating sheave system with respect to the elevator car to the side on the elevator car means that “the side on the elevator car” refers to a movement within the car height, said distance of movement being preferably the entire height of the elevator car.
It is also obvious to the person skilled in the art that the elevator car and the machine unit may be laid out in the cross-section of the elevator shaft in a manner differing from the lay-out described in the examples. Such a different lay-out might be e.g. one in which the machine is located behind the car as seen from the shaft door and the ropes are passed under the car diagonally relative to the bottom of the car. Passing the ropes under the car in a diagonal or otherwise oblique direction relative to the form of the bottom provides an advantage when the suspension of the car on the ropes is to be made symmetrical relative to the center of mass of the elevator in other types of suspension lay-out as well.
It is likewise obvious to the skilled person that an elevator applying the invention may be equipped differently from the examples described above. It is further obvious to the skilled person that the elevator of the invention can be implemented using almost any type of flexible hoisting means as hoisting ropes, e.g. flexible rope of one or more strands, flat belt, cogged belt, trapezoidal belt or some other type of belt applicable to the purpose.
It is also obvious to the person skilled in the art that the elevator of the invention can be implemented using different roping arrangements between the traction sheave and the diverting pulley/diverting pulleys to increase the contact angle than those described as examples. For example, it is possible to dispose the diverting pulley/diverting pulleys, the traction sheave and the hoisting ropes in other ways than in the roping arrangements described in the examples, such as e.g. by using DW, XW or CSW roping. It is also obvious to the skilled person that, in the elevator of the invention, the elevator may also be provided with a counterweight, in which case the counterweight has e.g. a weight below that of the car and is suspended by a separate roping arrangement.
Number | Date | Country | Kind |
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20030153 | Jan 2003 | FI | national |
20021959 | Nov 2002 | FI | national |
Number | Date | Country | |
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Parent | PCT/FI03/00818 | Nov 2003 | US |
Child | 11106618 | Apr 2005 | US |
Parent | PCT/FI03/00714 | Oct 2003 | US |
Child | 11106618 | Apr 2005 | US |