HK1081509B - Counterweight-less elevator - Google Patents

Description

Elevator without counterweight

Technical Field

The invention relates to an elevator without counterweight.

Background

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 resulted in, among other things, a wide variety of elevator solutions without machine room. Good examples of elevators without machine room are presented in technical specification elevators EP0631967(a1) and elevators EP 0631968. The elevators described in these specifications are fairly efficient in respect of space utilization as they make it possible to eliminate the space required for the elevator machine room in the building without the need to enlarge the elevator shaft. In the elevators presented in these specifications the machine is compact at least in one direction, but in other directions it is possible to have much larger dimensions than a normal elevator machine.

In these basically good elevator solutions, the freedom of choice of elevator lay-out solutions is given to the space constraints required by the hoisting machine. Space is required when the various arrangements required for rope passage. 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 compromising elevator function and operational quality. In a traction sheave elevator without machine room it is difficult to mount the hoisting machine in the elevator shaft, especially in solutions with machine above, because the hoisting machine is a rather large block of great 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 size and weight have in practice limited the scope of application of the concept of elevator without machine room, or at least retarded the introduction of said concept in larger elevators. In the modernization of elevators the space available in the elevator shaft often limits the scope of application of the concept of elevator without machine room. In many cases, especially when the hydraulic elevator is modernized or replaced, the concept of using a rope elevator without machine room is not very practical due to insufficient space in the shaft, especially in the case of hydraulic elevator solutions to be modernized/replaced without counterweight. A disadvantage of elevators provided with a counterweight is the cost of the counterweight and the space it requires in the shaft. Roller elevators, which are rarely used today, have the drawback of requiring heavy and large complex hoisting machines with high energy consumption.

Disclosure of Invention

The object of the invention is to achieve at least one of the following objectives. On the one hand it is an object of the invention to develop the elevator without machine room further so that the space in the building and elevator shaft is utilized more efficiently than before. This means that the elevator should be allowed to be installed in a fairly narrow elevator shaft if necessary. On the other hand, the object of the invention is to reduce the size and/or weight of the elevator or at least its machine. One objective is to achieve an elevator in which an elevator hoisting rope with a thinner hoisting rope traction and/or a smaller traction sheave has a good grip/contact to the traction sheave. A further object of the invention is to achieve an elevator solution without counterweight without compromising on the characteristics of the elevator.

The object of the invention should be achieved without compromising the possibility of changing the basic layout of the elevator.

According to the invention an elevator without counterweight is provided, in which elevator the hoisting machine engages a set of hoisting ropes by means of a traction sheave, the elevator car being at least partly supported by said hoisting ropes serving as a means of moving the elevator car, characterized in that the elevator car is suspended on the hoisting ropes by means of at least one diverting pulley from whose rim the hoisting ropes go upwards from both sides, and at least one diverting pulley from whose rim the hoisting ropes go downwards from both sides, and in that the traction sheave engages the rope portion between these diverting pulleys, said hoisting ropes being provided at their ends with rope tensioning devices for adjusting the rope tension.

Preferably one end of the hoisting ropes is secured substantially immovably relative to the elevator car so as to be movable together with the elevator car.

Preferably at least one end of the hoisting ropes is secured substantially immovably in relation to the elevator shaft.

Preferably the elevator comprises diverting pulleys from which at least two hoisting ropes go upwards and diverting pulleys from which at least two hoisting ropes go downwards.

Preferably both the number of diverting pulleys from which the hoisting ropes go upwards and the number of diverting pulleys from which the hoisting ropes go downwards are 3, 4 or 5.

Preferably both ends of the hoisting ropes are secured substantially immovably in relation to the elevator shaft.

Preferably both ends of the hoisting ropes are secured substantially immovably in relation to the elevator car so as to be movable together with the elevator car.

Preferably the continuous contact angle between the traction sheave and the hoisting ropes is at least 180.

Preferably the continuous contact angle between the traction sheave and the ropes is greater than 180.

Preferably the roping used between the traction sheave and a rope sheave acting as a diverting pulley is ESW roping.

Preferably the roping used between the traction sheave and a rope sheave acting as a diverting pulley is DW roping.

Preferably the roping used between the traction sheave and a rope sheave acting as a diverting pulley is XW roping.

Preferably, the hoisting ropes used are high strength hoisting ropes.

Preferably the strength of the steel wires of the hoisting ropes is greater than 2300N/mm²And less than 2700N/mm²。

Preferably the cross-sectional area of the steel wire of the hoisting rope is larger than 0.015mm²And less than 0.2mm²And the strength of the steel wires of the hoisting ropes is greater than 2000N/mm²。

Preferably the diameter of the hoisting ropes is less than 8 mm.

Preferably, the hoisting machine is particularly light in relation to the load.

Preferably, the traction sheave is coated with polyurethane, rubber or other friction material suitable for the purpose.

Preferably the traction sheave is made of cast iron at least in the area of the rope grooves.

Preferably the elevator is an elevator without machine room.

Preferably both ends of the hoisting ropes are secured substantially immovably in relation to the elevator shaft by means of springs.

Preferably both ends of the hoisting ropes are fastened substantially immovably in relation to the elevator car by means of springs.

Preferably the diameter of the hoisting ropes is between 3-5 mm.

Preferably, the rope groove is undercut.

Some inventive embodiments are also discussed in the descriptive section of the present application. The inventive content of the application can also be defined in different ways. The inventive content may also consist of several separate inventions, especially if the invention is examined in the light of expressions or implicit sub-tasks or from the point of view of advantages or categories of advantages achieved.

One or more of the following advantages, among others, may be obtained with the present invention.

Using a smaller traction sheave, a very light elevator and/or elevator machine is obtained;

the smaller coated traction sheave used makes it possible for the machine weight to be easily reduced to even about half the weight of the machine currently normally used in elevators without machine room. E.g. in the case of elevators designed for a nominal load below 1000kg, this means that the machine weighs 100-150kg or even less. By appropriate motor solutions and choice of materials, it is even possible to obtain machines with a weight lower than 100kg or even as small as about 50 kg;

good traction sheave grip, which is achieved in particular by double wrap roping, while the lightweight components allow the weight of the elevator car to be reduced significantly;

the compact machine size and the thin and substantially round ropes allow the elevator machine to be placed relatively freely in the shaft. The elevator solution of the invention can thus be implemented in a fairly wide variety of ways both in the case of elevators with machine above and in the case of elevators with machine below;

the elevator machine can advantageously be placed between the elevator car and a shaft wall;

all or at least part of the weight of the elevator car can be taken up by the elevator guide rails;

in the elevator to which the present invention is applied, the central suspension arrangement of the elevator car can be easily achieved, thereby reducing the lateral supporting force applied to the guide rail;

the application of the invention makes it possible to make effective use of the cross-sectional area of the shaft;

the invention reduces the installation time and the total installation cost of the elevator;

the manufacture and installation of the elevator are economical because many of its components are both smaller and lighter than those previously used;

the governor rope and the hoist rope are usually different in their properties, and they can be easily identified from each other during installation if the governor rope is thicker than the hoist rope; on the other hand, the speed control ropes and the hoisting ropes can also have the same structure, which will reduce confusion about these materials in the elevator delivery logistics and installation;

light and thin ropes are easy to handle, making it possible to considerably speed up the installation;

for example, in elevators for nominal loads below 1000kg, the thin and strong steel ropes of the invention have a diameter of the order of only 3-5mm, although thinner and thicker ropes may also be used;

with rope diameters of about 6mm or 8mm, a fairly large and fast elevator according to the invention can be achieved;

the traction sheave and the rope pulleys are small and light compared to those used in conventional elevators;

a smaller traction sheave makes it possible to use smaller operating brakes;

a smaller traction sheave reduces torque requirements, allowing a smaller motor with a smaller operating brake to be used;

since the traction sheave is small, a higher rotational speed is required to achieve a given elevator car speed, which means that the same motor output can be achieved by a smaller motor.

Either coated or uncoated ropes may be used;

the traction sheave and the rope pulleys may be implemented in such a way that after the coating on the pulley has been worn away, the rope will bite firmly on the pulley and thus a sufficient grip between the rope and the pulley is maintained in this emergency;

the use of a smaller traction sheave makes it possible to use a smaller elevator drive motor, which means that the drive motor adoption/manufacturing costs are reduced;

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

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

better grip and better contact between the rope and the traction sheave in the invention are achieved by increasing the contact angle between them;

the size and weight of the elevator car can be reduced due to the improved gripping force;

the space saving potential of the elevator of the invention increases substantially as the space required for the counterweight is at least partly avoided;

in the elevator of the invention, lighter and smaller machines and/or motors can be used;

due to the lighter and smaller elevator system, energy savings are achieved while cost savings are achieved;

the placement of the machine in the shaft can be chosen relatively freely, since the space required for the counterweight and the guide rails of the counterweight can be used for other purposes;

by installing at least the elevator hoisting machine, the traction sheave and the rope sheave acting together to the diverting pulley in a complete unit fitted as part of the elevator of the invention, significant savings in installation time and costs will be achieved;

in the elevator solution of the invention it is possible to arrange all the ropes in the shaft on one side of the elevator car, e.g. in the case of a rucksack-type solution the ropes can be arranged to run behind the elevator car in the space between the elevator car and the rear wall of the elevator shaft;

the invention makes it easy to implement the scenery elevator solution;

since the elevator solution of the invention does not necessarily comprise a counterweight, an elevator solution can be implemented in which the elevator car has elevator doors on several walls. In this case, the elevator car guide rails are arranged at the corners of the elevator car;

the elevator solution of the invention can be implemented in several different machine solutions;

the suspension means of the elevator car can be implemented with almost any suitable suspension ratio.

The main field of application of the invention is elevators designed only for transporting people and/or freight. A representative field of application of the invention is elevators with a speed range of about 1.0m/s or less but which may also be higher. For example, an elevator with a travel speed of 0.6m/s is easy to implement according to the invention.

In both passenger and freight elevators, many of the advantages achieved by the invention have been profoundly shown even in elevators for only 2-4 persons, and have been clearly shown in elevators for 6-8 persons (500-630 kg).

In the elevator of the invention, normal elevator hoisting ropes, such as the commonly used steel ropes, are applicable. In the elevator it is possible to use ropes made of artificial material and ropes in which the load-bearing part is made of artificial fibre, such as e.g. the so-called "aramid ropes", which have recently been proposed for use in elevators. Solutions that can be applied also include wire-reinforced flat ropes, especially because they allow a smaller bending radius. Particularly applicable in the elevator of the invention are elevator hoisting ropes twisted e.g. from round and strong wires. With round steel wires it is possible to twist the rope in many ways using wires of different or equal thickness. In the rope applicable to the present invention, the wire thickness is 0.4mm or less on average. Suitable ropes made of strong wires are those in which the average wire thickness is largeThose with a fineness of 0.3mm or less or even 0.2mm or less. For example, thin and strong 4mm ropes can be twisted relatively economically from steel wires so that the average wire thickness in the finished rope is in the range of 0.15-0.25mm, while the finest wires can have a thickness as small as only about 0.1 mm. The thin rope wires can be made very strong. In the invention, the strength is more than 2000N/mm²The rope wires of (1). A suitable range of the rope steel wire is 2300-². In principle, it is possible to use a material having a strength of up to about 3000N/mm²Or higher rope wires.

The elevator of the invention is preferably an elevator without machine room, in which elevator the hoisting machine engages the hoisting ropes by means of a traction sheave, and the elevator car is at least partly supported by said hoisting ropes, which serve as a conveying means for moving the elevator car. The elevator car is connected to the hoisting ropes via a diverting pulley of which at least one hoisting rope goes upwards from its rim from both sides and a diverting pulley of which at least one hoisting rope goes downwards from its rim from both sides, and in which elevator the traction sheave engages the rope portion between these diverting pulleys.

By increasing the contact angle by means of the rope sheave functioning as a diverting pulley, the grip between the traction sheave and the ropes can be increased. In this way the elevator car can be made lighter and its size can be reduced, thus increasing the space saving potential of the elevator. A contact angle of more than 180 between the traction sheave and the hoisting ropes is achieved by using one or more diverting pulleys.

Drawings

In the following, the invention will be described by means of examples of embodiments thereof with reference to the accompanying drawings, in which

Fig. 1 presents a diagrammatic view of a traction sheave elevator according to the invention;

fig. 2 presents a diagrammatic view of a second traction sheave elevator according to the invention;

fig. 3 presents a diagrammatic view of a third traction sheave elevator according to the invention;

fig. 4 presents a diagrammatic view of a traction sheave elevator according to the invention;

fig. 5 presents a diagrammatic view of a traction sheave elevator according to the invention;

fig. 6 presents a traction sheave to which the invention is applied;

FIG. 7 illustrates a lay-up solution consistent with the present invention;

fig. 8a shows a wire rope for use in the present invention;

fig. 8b shows a second steel cord for use in the present invention;

fig. 8c shows a third steel cord for use in the present invention;

fig. 9 presents some traction sheave roping arrangements according to the invention;

FIG. 10 illustrates an embodiment of the present invention;

FIG. 11 illustrates an embodiment of the present invention; and

figure 12 shows a diagram of the placement of a sheave according to the invention.

Detailed Description

Fig. 1 presents a diagrammatic view of the structure of an elevator. The elevator is preferably an elevator without machine room and the drive machine 10 is mounted in the elevator shaft. The elevator presented in the figure is a traction sheave elevator without counterweight and with machine above. The travel of the elevator hoisting ropes 3 is as follows: one end of the ropes is immovably fixed to an anchorage 16 in the upper part of the shaft, from which the ropes 3 go further to a diverting pulley 15 placed in the upper part of the shaft and from which diverting pulley 15 it goes further to a diverting pulley 13 placed above the elevator car, from which diverting pulley 13 it goes further upwards to the traction sheave 11 of the drive machine 10, passing around the traction sheave along its rope grooves. From the traction sheave 11 the ropes 3 go further downwards via the elevator car 1 moving along the guide rails 2 of the elevator to a diverting pulley 4 placed in the lower part of the shaft, from which diverting pulley 4 they go further to a diverting pulley below the elevator car, whereby the ropes 3 go further to a diverting pulley 6 in the lower part of the elevator shaft and then further to a diverting pulley 7 below the elevator car, whereby the ropes 3 go further to an anchorage 9 in the lower part of the elevator shaft, to which anchorage the other ends of the ropes 3 are immovably fastened. At the lower anchorage of the hoisting ropes 3 there is also a rope tensioning device 8, by means of which the rope tension can be adjusted. The tensioning device 8 may be e.g. a spring or a weight hanging freely at the end of the rope or some other suitable tensioning device solution. The drive machine 10 can in a preferred case be fixed e.g. to a car guide rail, while the diverting pulley 15 in the upper part of the shaft is mounted on a beam in the upper part of the shaft, which is fastened to the car guide rail 2. Diverting pulleys 5, 7, 13, 14 on the elevator car are mounted on the beam above and below the car. The diverting pulleys of the lower part of the shaft are preferably mounted on the shaft floor. In fig. 1 the traction sheave engages the rope portions between diverting pulleys 13 and 5, which is a preferred solution according to the invention.

The drive machine 10 placed in the elevator shaft is preferably of a flat construction, in other words the machine has a small thickness dimension compared to its width and/or height, or at least the machine is slim enough to be accommodated between the elevator car and a wall of the elevator shaft. The machine can also be placed in different ways, e.g. by arranging the slim machine partly or completely between an imaginary extension of the elevator car and a shaft wall. In the elevator of the invention, it is possible to use almost any type and design of drive machine 10 that can be fitted in the space provided for it. For example, geared or gearless machines may be employed. The machine may have a small and/or flat size. In the suspension solution according to the invention the rope speed is often high compared to the elevator speed, so that even a simple machine type can be used as a basic solution for the machine. The elevator shaft is advantageously provided with equipment required for the supply of power to the motor driving the traction sheave 11 and equipment required for elevator control, both of which can be placed in a common instrument panel 12 or mounted separately from each other or integrated partly or completely with the drive machine 10. A preferred solution is a gearless machine comprising a permanent magnet motor, the drive machine being fixable to a wall, ceiling, a guide rail or some other structure of the elevator shaft, such as a beam or frame. Another possibility is to mount the machine on the bottom of the elevator shaft in the case of an elevator with machine below. Fig. 1 presents a preferred suspension solution, in which the suspension ratio of the diverting pulleys above the elevator car and the diverting pulleys below the elevator car is in both cases the same 4: 1 suspension. Other suspension schemes may also be used to practice the invention. The elevator shown in the figure has automatic retractable doors, but other types of automatic doors or turning doors can be used within the framework of the invention. The elevator of the invention can also be implemented as a solution comprising a machine room or the machine can be mounted to move together with the elevator. In the invention the diverting pulleys connected to the elevator car can preferably be mounted on the same beam, which supports both the diverting pulleys above the elevator car and the diverting pulleys below the elevator car. This beam is fitted on the top of the elevator car, on the side of the elevator car or below the elevator car, on the elevator car frame or in some other suitable position in the elevator car structure. The diverting pulleys may also be fitted separately in place on the elevator car and in the shaft.

Fig. 2 presents another traction sheave elevator according to the invention. In which elevator the ropes go upwards from the machine. This type of elevator is generally a traction sheave elevator with machine below. The elevator car 201 is suspended on the hoisting ropes 203 of the elevator. The elevator drive machine unit 210 is mounted in the elevator shaft, preferably in the lower part of the shaft. The elevator car 201 moves in the elevator shaft along the elevator guide rails 202 guiding it.

In fig. 2, the hoisting ropes run as follows: one end of the ropes is fixed to an anchorage 216 in the upper part of the shaft, from which the ropes go downwards to diverting pulley 213, from which the ropes go further upwards to a first diverting pulley 215 mounted in the upper part of the shaft and from diverting pulley 215 to a diverting pulley 214 on the elevator car 201, from which it returns to diverting pulley 219 in the upper part of the shaft. From diverting pulley 219 the hoisting ropes go further to the traction sheave 211 driven by the drive machine 210. From the traction sheave the ropes go again upwards to a diverting pulley 204 mounted below the elevator car and, having passed around the latter, the hoisting ropes go via a diverting pulley 220 mounted in the lower part of the elevator shaft to a second diverting pulley 205 below the elevator car, from where the ropes go further to an anchorage 209 in the lower part of the elevator shaft, to which the other end of the hoisting ropes is fixed. A rope tensioning device 208 is also provided at the lower rope anchorage. The elevator shown in fig. 2 is a traction sheave elevator with machine below, in which the suspension ratio above and below the elevator car is 4: 1. In addition, less shaft space is needed above or below the elevator car, because the rope sheaves used as diverting pulleys have a smaller diameter than in earlier solutions, depending on how the rope sheaves are mounted on the elevator car and/or the frame of the elevator car.

Fig. 3 presents a diagrammatic illustration of the structure of an elevator according to the invention. The elevator is preferably an elevator without machine room and the drive machine 310 is installed in the elevator shaft. The elevator presented in fig. 3 is a traction sheave elevator with machine above, in which the suspension ratio above and below the elevator car is 6: 1. The passage of the elevator hoisting ropes 303 is as follows: one end of the ropes 303 is immovably fixed to an anchorage 316 in the upper part of the shaft, whereby the ropes run downwards to a diverting pulley 315 mounted at the side of the elevator car, whereby the ropes run further to the upper part of the elevator shaft, passing around diverting pulley 320, whereby the ropes 303 run further downwards to a diverting pulley 314, whereby the ropes return downwards to diverting pulley 313. Via the rope grooves of diverting pulley 313 the hoisting ropes go further upwards to the traction sheave 311 of the drive machine 310, passing around the traction sheave along the rope grooves of the sheave. From the traction sheave 311 the ropes 303 run further downwards to a diverting pulley 322, passing around the pulley along the rope grooves of the diverting pulley and then back upwards to the traction sheave 311, on which the ropes run in the rope grooves of the traction sheave. From the traction sheave 311 the ropes 303 go further downwards via the rope grooves of diverting pulley 322 to diverting pulley 307 placed in the lower part of the shaft, from where they go further to the elevator car 301 moving along the car guide rails 302 of the elevator and to a diverting pulley 306 mounted at the lower edge of the elevator car. The ropes are passed between diverting pulleys 318,319 in the lower part of the elevator shaft and diverting pulleys 306,305,304 in the lower part of the elevator car as many times as necessary to achieve the same suspension ratio for the part above the elevator car and the part below the elevator car. Thereafter the rope goes down to an anchoring means 308, such as a weight, which acts as a rope tensioning means hanging freely at the other end of the rope. In the situation shown in the figure, the hoisting machine and the diverting pulleys are preferably all placed on the same side of the elevator car. This solution is particularly advantageous in the case of a rucksack-type elevator solution, in which case the aforementioned components are arranged behind the elevator car in the space between the rear wall of the elevator car and the rear wall of the shaft. In a rucksack solution like this, the elevator guide rails 302 may preferably be arranged on the foremost part of the elevator car, e.g. at both sides of the elevator car/elevator car frame. The roping arrangement between the traction sheave 311 and the diverting pulley 322 is called double wrap roping, in which the hoisting ropes are passed around the traction sheave two and/or more times. In this way, the contact angle can be increased by two and/or more stages. For instance in the embodiment presented in fig. 3 a contact angle of 180 +180, i.e. 360, is achieved between the traction sheave 311 and the hoisting ropes 303. The double wrap roping presented in the figure can also be arranged in another way, e.g. by placing the diverting pulley on one side of the traction sheave, in which case a contact angle of 180 +90 or 270 is obtained as the hoisting ropes are passed twice around the traction sheave, or by placing the traction sheave in some other suitable position. A preferred solution is to arrange the traction sheave 311 and the diverting pulley 322 in such a way that the diverting pulley 322 will also function as a guide for the hoisting ropes 303 and as a damping wheel. Another advantageous solution is to make a complete unit comprising both the elevator drive machine with the traction sheave and one or more diverting pulleys with bearings, which are at a correct operating angle relative to the traction sheave to increase the contact angle. The operating angle is determined by the roping used between the traction sheave and the diverting pulley/diverting pulleys, which defines the arrangement of the mutual position and angle between the traction sheave and the diverting pulley/diverting pulleys in relation to each other in the unit. This unit can be mounted in place as a single unit in the same way as the drive machine. The drive machine may be fixed to a wall of the elevator shaft, to the ceiling, to a guide rail or guide rails and to some other structure, such as a beam or frame. In double wrap roping the diverting pulley can also function as a damping wheel when the diverting pulley has substantially the same dimensions as the traction sheave. In which case the ropes going from the traction sheave to the counterweight and elevator car pass via the rope grooves of the diverting pulley and the rope deviation caused by the diverting pulley is small. It can be said that the ropes coming from the traction sheave only touch the diverting pulley in the tangential direction. This tangential contact serves as a solution for damping the vibrations of the outgoing ropes, but it can also be used in other roping solutions.

Fig. 4 presents a diagrammatic illustration of the structure of a fourth elevator according to the invention. The elevator is preferably an elevator without machine room and the drive machine 410 is placed in the elevator shaft. The elevator presented in fig. 4 is a traction sheave elevator with machine above and with a suspension ratio of 7: 1 above and below the elevator car, which is a very good embodiment of the invention in respect of the suspension ratio. The passage of the ropes is mainly similar to that in fig. 3, but in this figure the starting point of the hoisting rope 403 is on the elevator car 401, to which the rope is essentially immovably secured. In this arrangement an odd suspension ratio is obtained for the part above the elevator car. Another difference with fig. 3 is that the number of diverting pulleys mounted in the upper part of the elevator shaft is one more than in fig. 3. The passage of the ropes to the hoisting machine 410 follows the same principles as in fig. 3. From the hoisting machine 410 the hoisting ropes run between diverting pulleys 407,418, 419,423 in the lower part of the elevator shaft and diverting pulleys 406,405, 404 mounted below the elevator car on the same principle as in fig. 3. In the lower part of the elevator car the same suspension ratio, i.e. an odd suspension ratio of 7: 1, is obtained by fixing the ropes to an anchorage 425 on the elevator car 401. Also placed at this fixing point is a rope tensioning device. In fig. 4 there is also a difference from fig. 3 in the roping between the traction sheave 411 and the diverting pulley 422. The roping arrangement presented in fig. 4 can also be referred to as X-wrap (XW) roping. Previously known concepts are Double Wrap (DW) roping, Single Wrap (SW) roping and Extended Single Wrap (ESW) roping. In X-wrap roping the hoisting ropes are caused to wrap around the traction sheave 411 with a large contact angle. For instance in the situation presented in fig. 4 a contact angle well over 180, i.e. about 270, is obtained between the traction sheave 411 and the hoisting ropes. The X-wrap roping presented in the figure can also be arranged in another way, for example by arranging two diverting pulleys at suitable places near the drive machine. In fig. 4 the diverting pulley 422 has been fitted in place at an angle relative to the traction sheave 807 such that the ropes will cross-wrap in a manner known per se so that the ropes are not damaged. In this figure the passage of the ropes from diverting pulley 413 is so arranged that the ropes go via the rope grooves of diverting pulley 422 to the traction sheave 411 of the drive machine 410, passing around the traction sheave along the traction sheave rope grooves. From the traction sheave 411 the ropes 403 go further downwards, cross-ing over the ropes going upwards and go further downwards via the rope grooves of the diverting pulley to diverting pulley 407.

Fig. 5 presents a diagrammatic view of the structure of an elevator according to the invention. The elevator is preferably an elevator without machine room and the drive machine 510 is placed in the elevator shaft. The elevator shown in the figure is a traction sheave elevator with machine above, with a 9: 1 suspension ratio above and below the elevator car. The travel of the elevator hoisting ropes 503 is as follows: one end of the ropes is fixed substantially immovably in relation to the elevator car at fixing point 530 so as to be movable with the elevator car, from where the ropes go upwards to diverting pulley 525 in the upper part of the shaft, from which the rope runs further between diverting pulleys 525,513, 524,514,520, 515,521, 526 in the manner described above, and from these diverting pulleys the ropes 503 go further to the traction sheave 511 of the drive machine 510, passing around the traction sheave along the rope grooves of the traction sheave. From the traction sheave 511 the ropes 503 run further downwards crosswise to the ropes going upwards to diverting pulley 522, passing around the diverting pulley 522 along the rope grooves of the diverting pulley 522. From diverting pulley 522 the ropes 503 go further downwards to a diverting pulley 528 in the lower part of the elevator shaft. The ropes then run further upwards from diverting pulley 528 in the manner described in connection with the previous figures between diverting pulleys 504, 505, 506, 507 in the lower part of the elevator car and diverting pulleys 528, 527, 526, 519, 518 in the lower part of the elevator shaft. In fig. 5, an odd suspension ratio is also obtained below the elevator car by fixing the hoisting ropes essentially immovably in relation to the elevator car at the fixing point 531, where a mounting means is also provided. The roping arrangement used between the traction sheave 511 and the diverting pulley 522 is called expanded single wrap roping. In extended single wrap roping the hoisting ropes are passed around the traction sheave with a large contact angle by using a diverting pulley. For instance in the situation shown in fig. 5 the contact angle between the traction sheave 511 and the hoisting ropes 503 is well over 180, i.e. about 270. The expanded single wrap roping presented in fig. 5 can also be arranged in another way, such as by arranging the traction sheave and the diverting pulley in a different way in relation to each other, such as opposite to each other than in fig. 5. Diverting pulley 522 is fitted in place at an angle to the traction sheave 511 so that the ropes pass crosswise in a manner known per se so that the ropes are not damaged.

Fig. 6 is a partial sectional view of a sheave 600 to which the present invention is applied. The rope grooves 601 are under the coating 602 on the rim 606 of the rope sheave. A space 603 is provided in the sheave hub for a bearing to mount the sheave. The rope sheave is also provided with holes 605 for bolts so that the rope sheave can be fastened with its side to an anchorage on the hoisting machine 10, e.g. to a rotating flange, to constitute the traction sheave 11, so that no separate bearing from the hoisting machine is needed. The coating material used on the traction sheave and the rope sheaves may consist of rubber, polyurethane or some corresponding elastic material that increases friction. The material of the traction sheave and/or the rope sheaves may also be chosen so that it constitutes, together with the hoisting ropes used, a material pair so that the hoisting ropes bite into the pulley after the coating on the pulley has been worn away. This ensures a sufficient grip between the sheave 600 and the hoisting ropes 3 in an emergency situation where the coating 602 has been worn off from the sheave 600. This feature allows the elevator to maintain its functionality and operational reliability in the described situation. The traction sheave and/or sheaves may also be made in such a way that only the rim 606 of the sheave 600 is made of a material that forms a grip-enhancing material pair with the hoisting ropes 3. The use of strong hoisting ropes that are considerably thinner than normal allows the traction sheave and the rope sheaves to be designed to a considerably smaller size and dimension than normal-sized ropes. This also makes it possible to use a smaller-sized motor having a smaller torque as the drive motor of the elevator, which results in a reduction in the manufacturing cost of the motor. For example in the elevator of the invention for a nominal load below 1000kg the traction sheave diameter is preferably 120-200mm, but it may even be smaller than this. The traction sheave diameter depends on the thickness of the hoisting ropes used. In the elevator of the invention, the use of a small traction sheave, e.g. for nominal loads below 1000kg, makes it possible to achieve machine weights even as low as about half the weight of the machine currently used, which means that elevator machines with weights of 100-150kg or less are produced. In the present invention, a machine is understood to comprise at least a traction sheave, a motor, a machine housing structure and a brake. The traction sheave diameter depends on the thickness of the hoisting ropes used. A diameter ratio D/D of 40 or higher is usually used, where D is the traction sheave diameter and D is the hoisting rope thickness. This ratio can be reduced somewhat at the expense of the wear resistance of the rope. In addition, the D/D ratio can be reduced without compromising the service life of the ropes if the number of ropes is increased at the same time, in which case the stress per rope will be smaller. Such a D/D ratio of less than 40 may be, for example, a D/D ratio of about 30 or even lower, such as 25. However, often reducing the D/D ratio significantly below 30 will substantially reduce the service life of the rope, although this can be compensated for by using a rope of a specific construction. Achieving a D/D ratio of below 20 is in practice very difficult, but may be achieved by using a rope specially designed for this purpose, although such a rope would most likely be expensive.

The weight of the elevator machine and its support elements used to hold the machine in place in the elevator shaft is at most about 1/5 of the nominal load. If the machine is supported exclusively or almost exclusively by one or more elevator guide rails, the total weight of the machine and its supporting elements may be less than about 1/6 or even less than 1/8 of the nominal load. The nominal load of an elevator refers to the load determined for an elevator of a given size. The support elements of the elevator machine may comprise e.g. beams, brackets or hangers for supporting or suspending the machine on a wall structure or ceiling of the elevator shaft or on the guide rails of the elevator, or fixtures for securing the machine to the sides of the elevator guide rails. An elevator will be readily achieved in which the machine dead weight without supporting members is below 1/7 for the nominal load or even about 1/10 or less for the nominal load. In the case of an elevator of a given nominal weight for a nominal load of 630kg, as an example of the weight of the machine, when the traction sheave diameter is 160mm and ropes having a diameter of 4mm are used, the combined weight of the machine and its supporting elements may be only 75kg, in other words the total weight of the machine and its supporting elements is about 1/8 of the nominal load of the elevator. As another example, with the same 160mm traction sheave diameter and the same 4mm hoisting rope diameter, the total weight of the machine and its supporting elements is about 150kg in the case of an elevator with a nominal load of about 1000kg, so that the machine and its supporting elements in this case have a total weight equal to the nominal load of about 1/6. As a third example, in an elevator designed for a nominal load of 1600kg and employing a traction sheave diameter of 240mm and a hoisting rope diameter of 6mm, the total weight of the machine and its supporting members will be about 300kg, in other words the total weight of the machine and its supporting members equals about 1/7 of the nominal load. By varying the hoisting rope suspension arrangement, a lower total weight of the machine and its supporting elements can be achieved. For example, when a suspension ratio of 4: 1, a traction sheave diameter of 160mm and a hoisting rope diameter of 4mm are used in an elevator with a design nominal load of 500kg, a total weight of the hoisting machine and its supporting elements of about 50kg will be achieved. In this case, the total weight of the machine and its supporting elements is as little as about 1/10 of the nominal load. When the size of the traction sheave is reduced considerably and a higher suspension ratio is used, the required torque output of the motor drops to a fraction compared to the starting situation. If, for example, a 4: 1 suspension ratio is used instead of 2: 1, and if a 160mm traction sheave is used instead of a traction sheave with a diameter of 400mm, the torque demand drops to one fifth without increasing losses. Thus, the machine size is also substantially reduced.

Fig. 7 is a solution in which the rope groove 701 is in the coating 702, which is thinner at both sides of the rope groove than at the bottom. In such a solution the coating is arranged in a base groove 720 provided in the rope sheave 700 so that the deformations produced in the coating by the pressure exerted by the rope on the coating will be small and mainly limited to the rope surface texture sinking into the coating. Such a solution often means in practice that the rope sheave coating comprises rope groove-specific sub-coatings separated from each other, but in view of manufacturing or other aspects it may be appropriate to design the rope groove coating such that it extends continuously over several rope grooves.

By making the coating thinner at the sides of the groove than at its bottom, the stress exerted by the rope on the bottom of the rope groove when sinking into the groove is eliminated or at least reduced. A lower maximum surface pressure on the rope and the coating is also obtained, since the pressure cannot be relieved laterally and is guided by the combined effect of the shape of the base groove 702 and the thickness variation of the coating 702 to support the rope in the rope groove 701. Making such a troughOne way of coating 702 is to fill the round-bottomed base groove 720 with coating material and then make a semicircular rope groove 701 in this coating material in the base groove. The shape of the grooves is well maintained and the load-bearing surface layer below the ropes provides a good resistance to the lateral propagation of the compressive stresses generated by the ropes. The lateral expansion or rather adjustment of the coating caused by the pressure is reinforced by the thickness and elasticity of the coating and weakened by the hardness and eventual strengthening of the coating. The coating thickness on the bottom of the rope groove can be made larger, even up to half the rope thickness, in which case a hard and inelastic coating is required. On the other hand, if a coating thickness corresponding to only about one tenth of the rope thickness is used, the coating material can be considerably softer. An elevator for 8 persons can be implemented with a coating thickness at the bottom of the groove equal to about one fifth of the rope thickness, if the rope and rope load are chosen appropriately. The coating thickness should be equal to at least 2-3 times the depth of the surface structure of the rope formed by the surface wires of the rope. Such a very thin coating, having a thickness even smaller than the thickness of the steel wires on the surface of the hoisting ropes, will not necessarily withstand the strains imposed on it. In practice the coating must have a thickness greater than this minimum thickness, because the coating will also have to accommodate rope surface variations that are rougher than the surface structure. Such a rougher area is formed, for example, where the difference in level between the strands of the rope is greater than the difference in level between the wires. In practice, a suitable maximum coating thickness is about 1-3 times the surface wire thickness. In the case of ropes normally used in elevators, which are designed for contacting the metal rope grooves and have a thickness of 8-10mm, this thickness specification results in a coating of at least about 1mm thickness. Since the traction sheave causes more rope wear than the other sheaves of the elevator, the coating on it will reduce the rope wear and thus also the need to provide the rope with thicker surface wires, which can be made smoother. Rope smoothness can naturally be improved by coating the rope with a material suitable for the purpose, such as polyurethane or equivalent. The use of thin wires allows the rope itself to be made thinner, since the thin wiresThe wire may be made of a stronger material than the thick steel wire. For example, with 0.2mm wire, a 4mm thick elevator hoisting rope of a fairly good construction can be produced. Depending on the thickness of the hoisting rope used and/or other factors, the steel wires in the steel rope may preferably have a thickness between 0.15mm and 0.5mm, in which range there are immediately available steel wires with good strength properties, wherein even a single steel wire has a sufficient wear resistance and a sufficiently low vulnerability. Above, ropes made of round steel wire have been discussed. Using the same principle, the rope can be twisted completely or partly from non-round profiled wires. 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 (1). With steel wires within this thickness range, steel wire strengths in excess of about 2000N/mm will be readily produced²And the cross section of the steel wire is 0.015mm²-0.2mm²And a large cross-sectional area of steel material relative to the cross-sectional area of the rope, as obtained by using the Warrington construction. For the purpose of the invention, it is particularly suitable that the steel wire has a strength of 2300N/mm²-2700N/mm²Ropes within the scope of this invention are considered because such ropes have a great load-bearing capacity with respect to rope thickness, while the high hardness of the strong wires does not cause substantial difficulties in the use of such ropes in elevators. A traction sheave coating well suited for such a rope has been found to be clearly below 1mm thick. However, the coating should be thick enough to ensure that it will not be easily scraped off or pierced by e.g. occasional sand grains or similar particles that may be trapped between the rope grooves and the hoisting ropes. Thus, the desired minimum coating thickness, even when using a filament hoisting rope, is about 0.5-1 mm. For hoisting ropes with small-surface wires and an otherwise relatively smooth surface, a coating having a thickness in the form of a + Bcosa is very suitable. However, such a coating can also be used for ropes whose surface strands touch the rope grooves at a distance from each other, because if the coating material is sufficiently hard, each strand touching the rope grooves is to some extent supported separately and the supporting force is the same and/or as desired. In the formula A + BcosaA and B are constants, so that a + B is the coating thickness at the bottom of the rope groove 701 and the angle a is the angular distance from the bottom of the rope groove measured from the centre of curvature of the rope groove cross-section. The constant a is greater than or equal to zero and the constant B is always greater than zero. The tapering of the thickness of the coating towards the two sides can also be determined in other ways than by using the formula a + Bcosa so that the elasticity decreases towards the two sides of the rope groove. The elasticity at the central part of the rope groove can also be increased by making an undercut rope groove and/or by adding a different material part of a certain elasticity to the coating on the bottom of the rope groove, whereby the elasticity has been increased in addition to the increase of the material thickness by using a material that is softer than the rest of the coating.

Fig. 8a, 8b and 8c are cross-sections of steel cords used in the invention. The rope in these figures comprises thin steel wires 803, a coating 802 on the steel wires and/or partly between the steel wires, while in fig. 8a there is also a coating 801 covering the steel wires. The rope shown in fig. 8b is an uncoated steel rope with a rubber-like filler added to its inner structure, while fig. 8a shows a steel rope provided with a coating in addition to the filler added to its inner structure. The rope shown in fig. 8c has a non-metallic core 804, which may be a solid or fibrous member made of plastic, natural fibers or other materials suitable for the purpose. The fibrous member is good if the rope is to be lubricated, in which case the lubricant will collect in the fabric core. The cord thus acts as a lubricant reservoir. The essentially round-section steel cord used in the elevator of the invention may be coated, uncoated and/or provided with a rubber-like filler, such as polyurethane or some other suitable filler, which is added to the inner structure of the rope and serves as a lubricant lubricating the rope and also balancing the pressure between the wires and the strands. The use of a filler makes it possible to obtain a rope which does not require lubrication, so that the surface can be dry. The coating used in the steel cord may be made of the same or nearly the same material as the filler or a material having properties such as friction and wear resistance that are better suited for use as a coating and for this purpose than the filler. The coating of the steel cord may also be performed such that the coating material partly penetrates the cord or passes through the entire thickness of the cord, giving the cord the same properties as the above-mentioned filler. The use of thin and strong steel cords according to the invention is possible because the steel wires used are steel wires having a certain strength, allowing the rope to be made considerably thinner than previously used steel cords. The ropes shown in fig. 8a and 8b are steel ropes having a diameter of about 4 mm. For example, the thin and strong steel wire rope of the invention preferably has a diameter of about 2.5-5mm for elevators with a nominal load below 1000kg and about 5-8mm for elevators with a nominal load above 1000 kg. In principle, it is possible to use ropes thinner than this, but in this case a large number of ropes will be needed. In addition, by increasing the suspension ratio, ropes thinner than those described above can be used for the respective loads, and at the same time a smaller and lighter elevator machine can be achieved.

In the elevator of the invention it is also possible to use ropes having a diameter exceeding 8mm, if desired. Also ropes with a diameter below 3mm may be used.

Fig. 9a, 9b, 9c, 9d, 9e, 9f and 9g show some variants of the roping arrangements according to the invention that can be used between the traction sheave 907 and diverting pulley 915 to increase the contact angle between the ropes 903 and the traction sheave 907, in which arrangements the ropes 903 go downwards from the drive machine 906 to the elevator car and diverting pulleys. These roping arrangements make it possible to increase the contact angle between the hoisting ropes 903 and the traction sheave 907. In the invention the contact angle alpha refers to the arc length of contact between the traction sheave and the hoisting ropes. The magnitude of the contact angle a may be expressed, for example, in degrees, as is done in the present invention, but may also be expressed in other terms, such as in radians or equivalent units. The contact angle alpha is plotted in detail in fig. 9 a. In the other figures, the contact angle α is not explicitly indicated, but it can also be seen from the other figures without a particular individual description.

The roping arrangements shown in figures 9a, 9b and 9c represent some variations of the aforementioned X wrap roping. In the arrangement presented in fig. 9a, the ropes 903 are passed around diverting pulley 915 along the rope grooves, over it to the traction sheave 907, along which the ropes are passed around and then run back again to diverting pulley 915, passing crosswise with respect to the rope portions coming from the diverting pulley, and the passage of the ropes is continued further. The cross-passing of the ropes 903 between diverting pulley 915 and the traction sheave 907 can be implemented e.g. by placing the diverting pulley at such an angle relative to the traction sheave that the ropes will cross each other in a manner known per se so that the ropes 903 are not damaged. In fig. 9a, the hatched area indicates the contact angle α between the ropes 903 and the traction sheave 907. The magnitude of the contact angle alpha is about 310 deg. in this figure. The diameter of the diverting pulley can be dimensioned as a means of determining the suspension distance to be formed between the diverting pulley 915 and the traction sheave 907. The magnitude of the contact angle can be changed by changing the distance between the diverting pulley 915 and the traction sheave 907. The size of the angle alpha can also be varied by varying the diameter of the diverting pulley and/or by varying the diameter of the traction sheave and also by varying the ratio between the diameters of the diverting pulley and the traction sheave. Fig. 9b and 9c are examples of implementing a corresponding XW roping arrangement using two diverting pulleys.

The roping arrangements shown in figures 9d and 9e are two different variants of the double wrap roping described above. In the roping arrangement of fig. 9d the ropes run via the rope grooves of diverting pulley 915 to the traction sheave 907 of the drive machine 906, passing around it along the rope grooves of the traction sheave. From the traction sheave 907, the ropes 903 go further downwards back to diverting pulley 915, passing around it along the rope grooves of the diverting pulley and then back to the traction sheave 907, in which the ropes pass around the traction sheave in the rope grooves. From the traction sheave 907 the ropes 903 go further downwards via the rope grooves of the diverting pulley. In the roping arrangement presented in the figure the hoisting ropes are passed around the traction sheave twice and/or more times. By means of this, the contact angle can be increased by two and/or more stages. For instance in the situation shown in fig. 9d a contact angle of 180 +180 is achieved between the traction sheave 907 and the ropes 903. In double wrap roping the diverting pulley 915 also functions as a damping wheel when the diverting pulley 915 has substantially the same size as the traction sheave 907. In this case the ropes going from the traction sheave 907 to the diverting pulley and the elevator car pass via the rope grooves of diverting pulley 915, and the rope deflection caused by the diverting pulley is very small. Or it can be said that the ropes coming from the traction sheave only touch the diverting pulley in the tangential direction. Such tangential contact serves as a solution damping the vibrations of the outgoing ropes, but it can also be used in other roping arrangements. In this case the diverting pulley 915 also functions as a rope guide. The ratio of the diameters of the diverting pulley and the traction sheave can be varied by varying the diameter of the diverting pulley and/or the traction sheave. This can be used as a means of determining the contact angle and adapting it to a desired size. By using DW roping a forward bending (forward bending) of the ropes 903 is achieved, which means that in DW roping the ropes 903 are bent in the same direction on the diverting pulley 915 and on the traction sheave 907. DW roping can also be implemented in other ways, such as e.g. in fig. 9e, where a diverting pulley 915 is placed on one side of the drive machine 906 and the traction sheave 907. In this roping arrangement the ropes 903 run in a manner corresponding to fig. 9d, but in this case a contact angle of 180 ° +90 °, i.e. 270 °, is obtained. In DW roping, if the diverting pulley 915 is placed on the side of the traction sheave, higher demands are placed on the mounting of the bearings and diverting pulley because it is affected by greater stresses and load forces than in the embodiment shown in fig. 9 d.

Figure 9f is an embodiment of the invention applying an extended single wrap roping as described above. In the roping arrangement presented in fig. 9f, the ropes 903 run to the traction sheave 907 of the drive machine 906, passing around it along the rope grooves of the traction sheave. From the traction sheave 907, the ropes 903 go further downwards, cross-wise with respect to the ropes going upwards and go further to a diverting pulley 915, passing around it along the rope grooves of the diverting pulley 915. From diverting pulley 915, the ropes 903 continue to go ahead. In expanded single wrap roping the hoisting ropes are passed around the traction sheave with a larger contact angle by using a diverting pulley than in ordinary single wrap roping. For instance in the situation shown in fig. 9f, a contact angle of about 270 between the ropes 903 and the traction sheave 907 is achieved. The diverting pulley 915 is fitted in place at an angle such that the ropes run crosswise in a manner known per se, so that the ropes are not damaged. An elevator implemented according to the invention can be implemented with a very light elevator car due to the contact angle achieved with the extended single wrap roping. One possibility to increase the contact angle is presented in fig. 9g, where the hoisting ropes do not run crosswise relative to each other after passing around the traction sheave and/or diverting pulley. By using such a roping arrangement it is also possible to increase the contact angle between the hoisting ropes 903 and the traction sheave 907 of the drive machine 906 to a magnitude significantly exceeding 180 deg..

Fig. 9a, b, c, d, e, f and g are different variants of roping arrangements between the traction sheave and the diverting pulley/diverting pulleys, in which the ropes go downwards from the drive machine to the counterweight and to the elevator car. In the case of an elevator embodiment according to the invention with machine below, the roping arrangements can be implemented in a corresponding manner by reversing them so that the ropes go upwards from the elevator drive machine to the diverting pulleys and the elevator car.

Fig. 10 presents a further embodiment of the invention, in which the elevator drive machine 1006 together with a diverting pulley 1015 is fitted on the same mounting base 1021 in a ready-made unit 1020, which can be so fitted as to form part of an elevator according to the invention. The unit 1020 comprises an elevator drive machine 1006, a traction sheave 1007 and a diverting pulley 1015 pre-fitted on a mounting base 1021, the traction sheave and the diverting pulley being pre-fitted at a correct operating angle relative to each other according to the roping arrangement used between the traction sheave 1007 and the diverting pulley 1015. The unit 1020 may comprise more than one diverting pulley 1015 or it may comprise only the drive machine 1006 fitted on the mounting base 1021. The arrangement can be installed in an elevator according to the invention like a drive machine, the installation arrangement having been described in more detail in connection with the previous figures. This device can be used, if necessary, in connection with any of the roping arrangements described above, such as for example the embodiments using ESW, DW, SW or XW roping. By equipping the above-described arrangement as part of an elevator according to the invention, considerable savings can be made in installation costs and time required for installation.

Fig. 11 presents an embodiment of the invention in which the diverting pulley 1113 of the elevator is fitted in a ready-made unit 1114, which can be placed in the upper part and/or in the lower part of the shaft and/or in the elevator car, and in which unit several diverting pulleys can be fitted. By means of which faster roping can be achieved and the diverting pulleys can be arranged compactly to form a single structure where required. The device can be provided with an unlimited number of diverting pulleys, which can be fitted in the device at a desired angle.

Fig. 12 shows how the rope sheave 1204, which is used to suspend the elevator car and its components and is mounted on a horizontal beam 1230 comprised in the structure supporting the elevator car 1201, is arranged in relation to the beam 1230. The sheave 1204 shown in this figure may have a height equal to or less than the height of the beam 1230 included in the structure. The beam 1230 supporting the elevator car 1201 can be placed either below or above the elevator car. The sheave 1204 can be placed completely or at least partially inside the beam 1230, as shown in the figure. The passage of the elevator hoisting ropes 1203 in this figure is as follows: the hoisting ropes 1203 run to a coated sheave 1204 mounted on a beam 1230 comprised in the structure supporting the elevator car 1201, from where the hoisting ropes are protected by the beam and run along the rope grooves of the sheave. The elevator car 1201 rests on a beam 1230 comprised in the structure, on shock absorbers 1229 placed between them. The beam 1230 at the same time functions as a rope protector for the hoisting rope 1203. Beam 1230 may be a C-, U-, I-, Z-shaped beam or a hollow beam or equivalent. The beam 1230 can support several rope sheaves fitted on it and serving as diverting pulleys in different embodiments of the invention.

A preferred embodiment of the elevator of the invention is an elevator without machine room with machine above, the drive machine of which comprises a coated traction sheave and employs thin hoisting ropes of substantially round cross-section. The contact angle between the hoisting ropes of the elevator and the traction sheave is greater than 180. The elevator comprises an arrangement comprising a mounting base on which the drive machine, the traction sheave and the diverting pulley are pre-mounted, said diverting pulley being fitted at a correct angle relative to the traction sheave. The device is secured to the elevator guide rails. The elevator is implemented without counterweight with a suspension ratio of 9: 1 so that the elevator ropes run in the space between one of the walls of the elevator car and a wall of the elevator shaft.

Another preferred embodiment of the elevator of the invention is an elevator with a suspension ratio of 10: 1 above and below the elevator car without counterweight. This embodiment is implemented using hoisting ropes of usually optionally 8mm diameter and a traction sheave made of cast iron at least in the area of the rope grooves. The traction sheave has undercut rope grooves and the contact angle to the traction sheave has been adjusted to 180 or more by means of a diverting pulley. When using normal 8mm ropes the traction sheave diameter is preferably 340 mm. The diverting pulleys used are larger sheaves having a diameter of 320, 330, 340mm or even more in the case of a normal 8mm hoisting rope.

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 invention. The number of times the hoisting ropes are passed between, for example, the upper part of the elevator shaft and the elevator car and between the diverting pulleys in the lower part and the elevator car is not a very decisive question as regards the basic advantages of the invention, although some additional advantages are achieved by using a number of rope passages. The use of elevators is generally accomplished so that the ropes are passed to the elevator car as many times from above as from below, and the suspension ratios of the diverting pulleys going upwards and the suspension ratios of the diverting pulleys going downwards are thus the same. It is also obvious that the ropes do not necessarily have to pass under the elevator car. In accordance with the examples described above, the skilled person can vary the embodiment of the invention, and the traction sheaves and sheaves, instead of being coated metal sheaves, may also be uncoated metal sheaves or uncoated sheaves made of some other metal suitable for the purpose.

It is further obvious to the person skilled in the art that the metallic traction sheaves and rope sheaves used in the invention, which are coated with a non-metallic material at least in the area of their grooves, may be implemented using a coating material consisting of e.g. rubber, polyurethane or some other material suited to the purpose.

It is also obvious to the person skilled in the art that the elevator car and the machine unit can be arranged in the cross-section of the elevator shaft in a different arrangement than described in the examples. Such a different arrangement may e.g. be one in which the machine is located behind the elevator car as seen from the shaft door and the ropes are passed under the elevator car in a diagonal direction with respect to the bottom of the elevator car. When the suspension of the elevator car on the ropes is made symmetrical with respect to the center of gravity of the elevator, the ropes form advantages in the diagonal or otherwise oblique direction with respect to the bottom shape below the elevator car by also among other types of suspension arrangements.

It is further obvious to the person skilled in the art that the equipment needed for supplying power to the motor and the equipment needed for elevator control can be placed elsewhere than in connection with the machine arrangement, e.g. in a separate instrument panel. It is also possible to fit the components of the equipment needed for control into separate devices which can then be placed in different places in the elevator shaft and/or in other parts of the building. It is also obvious to the person skilled in the art that an elevator applying the invention can be equipped differently from the examples described above. It is further obvious to the skilled person that the suspension solutions according to the invention can also be implemented using almost any type of flexible hoisting means, such as flexible rope of one or more strands, flat belt, toothed belt, trapezoidal belt or some other type of belt suited to the purpose, as ropes.

It is also obvious to the skilled person that instead of using ropes with a filler as shown in fig. 5a and 5b, the invention can be implemented using ropes without filler, which are either lubricated or not. Furthermore, it is also obvious to the person skilled in the art that the ropes can be twisted in many different ways.

It is also obvious to the skilled person that the average value of the wire thickness is understood to mean a statistical, geometric or arithmetic mean. To determine the statistical mean, standard deviation and gaussian distributions may be utilized. It is further obvious that the wire thickness in the rope may vary, for example, even by a factor of 3 or more.

It is also obvious to the person skilled in the art that the elevator of the invention can be implemented using different roping arrangements than those described as examples to increase the contact angle between the traction sheave and the diverting pulley/diverting pulleys. For instance the diverting pulley/diverting pulleys, the traction sheave and the hoisting ropes can be arranged in other ways than in the roping arrangements described in the examples. It is also obvious to the skilled person that in the elevator of the invention the elevator can also be provided with a counterweight, in which elevator, for example, the counterweight preferably has a weight below that of the elevator car and is suspended by means of separate roping.

Claims (24)

1. Elevator without counterweight, in which elevator the hoisting machine (10) engages a set of hoisting ropes (3) by means of a traction sheave (11), the elevator car (1) being at least partly supported by said hoisting ropes as a means of moving the elevator car (1), characterized in that the elevator car is suspended on the hoisting ropes (3) by means of at least one diverting pulley (13, 14) from whose rim the hoisting ropes go upwards from both sides, and at least one diverting pulley (7, 5) from whose rim the hoisting ropes go downwards from both sides, and in that the traction sheave (11) engages the rope portion between these diverting pulleys (13, 5), at the ends of which hoisting ropes a rope tensioning device is arranged for adjusting the rope tension.

2. Elevator according to claim 1, characterized in that one end of the hoisting rope is fastened essentially immovably in relation to the elevator car so as to be movable together with the elevator car.

3. Elevator according to claim 1, characterized in that at least one end of the hoisting ropes is secured substantially immovably in relation to the elevator shaft.

4. Elevator according to any one of the preceding claims, characterized in that it comprises at least two diverting pulleys from which the hoisting ropes go upwards and at least two diverting pulleys from which the hoisting ropes go downwards.

5. Elevator according to claim 4, characterized in that the number of diverting pulleys from which the hoisting ropes go upwards and the number of diverting pulleys from which the hoisting ropes go downwards are both 3, 4 or 5.

6. An elevator according to any one of claims 1-3, characterized in that both ends of the hoisting ropes are secured substantially immovably in relation to the elevator shaft.

7. An elevator according to any one of claims 1-3, characterized in that both ends of the hoisting rope are fastened essentially immovably in relation to the elevator car so as to be movable with the elevator car.

An elevator according to any one of claims 1-3, characterized in that the continuous contact angle between the traction sheave and the hoisting ropes is at least 180 °.

9. Elevator according to any one of claims 1-3, characterized in that the continuous contact angle between the traction sheave and the ropes is greater than 180 °.

10. Elevator according to any one of claims 1-3, characterized in that the roping used between the traction sheave and a rope sheave serving as a diverting pulley is ESW roping.

11. Elevator according to any one of claims 1-3, characterized in that the roping used between the traction sheave and a rope sheave serving as a diverting pulley is DW roping.

12. Elevator according to any one of claims 1-3, characterized in that the roping used between the traction sheave and a rope sheave serving as a diverting pulley is XW roping.

13. Elevator according to any one of claims 1-3, characterized in that the hoisting ropes used have a strength of more than 2000N/mm²Hoisting ropes of rope wires.

14. Elevator according to any one of claims 1-3, characterized in that the strength of the steel wires of the hoisting ropes is greater than 2300N/mm²And less than 2700N/mm²。

15. Elevator according to any one of claims 1-3, characterized in that the cross-sectional area of the steel wires of the hoisting ropes is larger than 0.015mm²And less than 0.2mm²And the strength of the steel wires of the hoisting ropes is greater than 2000N/mm²。

16. Elevator according to any one of claims 1-3, characterized in that the diameter of the hoisting ropes is less than 8 mm.

17. Elevator according to any one of claims 1-3, characterized in that the weight of the hoisting machine is substantially less than the load.

18. Elevator according to any one of claims 1-3, characterized in that the traction sheave is coated with polyurethane or rubber.

19. Elevator according to any one of claims 1-3, characterized in that the traction sheave is made of cast iron at least in the area of the rope grooves.

20. Elevator according to claim 1, characterized in that the elevator is an elevator without machine room.

21. Elevator according to claim 6, characterized in that both ends of the hoisting ropes are secured substantially immovably in relation to the elevator shaft by means of springs.

22. Elevator according to claim 7, characterized in that both ends of the hoisting rope are fastened substantially immovably in relation to the elevator car by means of springs.

23. Elevator according to claim 16, characterized in that the diameter of the hoisting ropes is between 3-5 mm.

24. Elevator according to claim 19, characterized in that the rope grooves are undercut.