EP2356055B1 - Traction mechanism, tractive drive comprising said traction mechanism, and lift installation - Google Patents

Description

The invention relates to a traction means, in particular for an elevator installation, a traction mechanism drive with this traction means and at least one traction sheave and an elevator installation, comprising this traction mechanism drive.

Traction means and traction mechanisms for elevator systems are known in the art. Ropes or belts are frequently used, with flat belts, V-ribbed belts or toothed belts being used as belts.

In the case of ropes as traction means, each individual rope is uniquely assigned its own rope groove on the traction sheave or other disk which drives the traction means. Each rope dives at least in part of its diameter in the corresponding rope groove. Each individual rope is an independent tension element and can also be operated individually. For higher outputs, either several ropes can be used in parallel or the rope diameter can be increased. The single rope is not only traction means for transmitting the tensile forces, but is also directly involved in the transmission of traction forces. Ropes as traction means have the advantage that the force is transmitted directly from the traction sheave on the ropes.

In belts as traction means several adjacent ropes are always embedded as a tensile carrier in a common elastomeric belt body. The tension members are completely encased with the elastomer material of the belt body, enclosed and embedded in this. The plane of the tension members lies far above the contact surface, which forms the belt with the corresponding pulley, wherein the timing belt Belt toothing, for V-ribs the trowel plane and for flat belts directly the flat belt surface can be considered as a contact surface. Between the tension member and the corresponding pulley a thick rubber layer is arranged in comparison to the diameter of the tension member. Here the tension members are exclusively responsible for the transmission of tensile forces, while the elastomeric material transmits the traction forces. Thus, the belt is subjected as a traction means, in particular the elastomer region between tension members and contact surface, during operation, high shear and shear stresses, whereby the risk of fatigue of the elastomeric material consists.

The EP 1 396 458 A2 discloses, for example, an elevator device in which a flat belt made of elastomeric material reinforced with reinforcements is used as the traction means. The EP 1 555 234 B1 discloses an elevator system with a V-ribbed belt.

Belts offer over individual ropes the advantage that on the one hand the handling is easier, since during construction or maintenance of the belt drive not every single rope must be placed on each corresponding groove of the traction disc, but only the elastomeric body in which the tension members are embedded. In addition, small traction sheave diameter can be used because the embedded tension members usually have relatively small diameters. In addition, belts as traction means are virtually maintenance-free, since no lubrication is required. However, in addition to friction between the traction sheave and elastomer, the transferable force is u.a. also dependent on the shear strength of the elastomeric material. Due to the shear of the elastomeric material such a belt is fatigued.

For safety reasons, always at least two, usually three to five belts must be used in parallel in elevator systems. Since the belts contain a multitude of thin tension members (single ropes), the belt becomes relatively wide compared to a rope of equal strength. If now several belts are used in parallel, relatively wide traction discs and pulleys are required.

The US Pat. No. 6,739,433 discloses a traction means for an elevator system, which is designed as a profiled flat belt, so that the area available for friction between traction disk and belt is increased. The transferable force is thus higher than in a non-profiled flat belt, but here is the zone of power transmission between the traction sheave and traction means still clearly spaced from the tension members by a thick compared to the diameter of a tension carrier elastomer layer of the elastomer body, so that the elastomeric material of Flat belt is also heavily loaded on shear.

From the not yet published DE 10 2007 021 434.2 the Applicant has become known a traction means, which consists of a plurality of juxtaposed and spaced apart tension members in the form of steel cables, which are sheathed by elastomer and are interconnected by a common backing layer.

EP 1 746 061 A1 discloses a support means end connection for attaching a suspension means in an elevator installation. The suspension element is in the form of a V-ribbed belt and has an elastomer sheathing.

The invention has for its object to provide a traction means of the type described, which is easy to handle and which can efficiently transfer high tensile forces without the risk of premature material fatigue. With respect to the traction mechanism of traction means and traction sheave high tensile forces without the risk of premature material fatigue should be transferred and it should be compared to the known belt technology a less broad-based drive unit must be required.

This object is achieved in relation to the traction means in that the traction means has tensile carriers which are encased by elastomeric material to coated tension members, wherein the sheathed tensile carriers in the cross section of the traction means in a plane next to each other are arranged spaced from each other, so that between two sheathed tension members a free space is formed, wherein the sheathed tensile carriers are connected by a back layer with each other, wherein the free space on the side facing away from the back layer from beginning to at least beyond the center of the reinforcing member and wherein the ratio of the second diameter of the sheathed strength member to the first diameter of the reinforcement is between 1.05 and 2.25.

By this arrangement, the advantages of the belt technology with those of the rope technology are synergistically connected to those skilled in the art completely surprising. The traction device according to the invention, which can also be referred to as a "composite rope", is easy to handle and is almost maintenance-free.

The traction device according to the invention consists of several tension members, which are comparable to several individual ropes of the rope technology. The tensile carriers are sheathed with a very thin elastomer layer to the diameter of the tension member and connected to each other with a backing layer. The tension members are spaced apart on their lying on the traction disc wide side only by a very thin elastomer layer of the traction surface. This has the advantage that the thin sheathing material of the reinforcement is only slightly subjected to shear and material fatigue hardly takes place, the forces can still be transferred very well. Can be measured, the ratio of the second diameter of the coated strength member to the first diameter of the strength member, for example, in the plane which is spanned by the centers of the strength member.

The fact that there is a free space between the coated reinforcements, a weight saving and thus easy handling is achieved. In addition, the free space allows engagement of the tension members of the traction means in corresponding grooves of the traction sheave, with which the traction means can cooperate.

The object is achieved with respect to the traction mechanism in that it consists of a described in this application traction means and at least one traction sheave through which the traction means is driven, wherein each sheathed tensile carrier of the traction means engages in a respective corresponding groove of the traction sheave, said the elastomeric backing layer is disposed on the side of the tension members facing away from the side engaging the grooves of the traction sheave, and wherein at least one bare tensile member engages at least 5% of its diameter in the corresponding groove of the traction sheave.

Due to the directly engaging in the grooves of the traction sheave tension member is given a high power transmission. The zone of power transmission between traction sheave and traction means lies directly in the engagement zone. Due to their small thickness, the shear strength of the sheath is of very little importance. It is created an efficient working traction drive, with the high tensile forces can be transmitted without the risk of premature fatigue of the traction device. It is only a traction device according to the invention is required, not several ropes as in the rope technique or belt in the belt technology, so that a less broad-based drive unit can be used. It can be comparatively thin tensile carrier in the traction device according to the invention use, so that small traction disc diameter and narrow traction discs are structurally possible. For each traction means only one connecting element for connection to the example to be lifted elements is necessary.

It is advantageous if the thickness of the sheath of the tension member is in the range of 0.2 to 2 mm. In a preferred embodiment of the invention, the thickness of the sheath of the tension member is in the range of 0.5 to 1 mm. With these small thicknesses of the sheathing, this is subjected to a particularly low level of shear and the transmittable tensile force is correspondingly high. The life of the traction means and their handling are improved.

The sheath of the tension members and the back layer consist in one embodiment of the same material.

In a development of the invention, it is provided that the casing consists of a first elastomer, which differs from a second elastomer of the back layer. By using different elastomers, a particularly wide variety of material combinations can be used, so that the traction means can be adjusted individually to a large number of applications.

Advantageously, the elastomer or elastomers is preferably a polyurethane or polyurethane. Polyurethane has both good friction and good adhesion properties and is relatively insensitive to shear.

In a preferred development of the invention, the sheathing of the individual cables has an outer contour facing the traction sheave whose cross-section is a part-circular shape. The sheathing in all embodiments in cross-section in approximately circular reinforcement is carried out with uniform thickness around the reinforcement around. The shear stresses during operation of the traction mechanism are the lowest in this embodiment.

In other developments of the invention, the cross section of the outer contour is not part-circular, but for example trapezoidal, conical, elliptical, arcuate or square. The configuration of the cross sections of the casing in different geometries has the advantage that the composite rope is therefore adaptable to a large number of traction disk profiles.

In a further development of the invention, the ratio of the overall diameter of the sheathed tension members (d2) to the thickness (D) of the composite means is ≦ 1. As a result, the material load, in particular with back deflection of the traction means via a smooth disc, is reduced below the tension member. If d2 equaled D, then the layer thickness at the back of the traction device would be equal to the layer thickness on the traction side and the material load at the back deflection of the traction device over a smooth disc would be very high.

In a development of the invention, the back layer has a thickness c, where c < half the thickness (D) of the traction means. However, the thickness c may be variable, wherein the thickness c above the center of the tension member is thinner than between the tension members above the free space. C has at least the layer thickness of the sheath at its thinnest point. The maximum layer thickness of c should not exceed ½ D, as otherwise the bending flexibility will decrease considerably and larger bending diameters will be necessary.

In a further development of the invention, the individual ropes of the composite rope are spaced apart such that the distance between the centers of the individual ropes is less than or equal to five times the diameter d1 of the uncoated tension members and minimal d1 + 1.5 mm.

These geometrical relationships, which can be combined with one another, serve for the optimal design of the traction means, so that the advantages with respect to flat belts remain and the traction carriers engage in the grooves of the traction disk and can transmit the forces optimally.

In a further embodiment of the invention, the back layer has a profiled surface on its side facing away from the traction disk. This profiling is used to better guide the traction device, if this must be performed over the spine around pulleys.

In a further embodiment of the invention, each traction device on at least four tension members. The security against twisting of the traction means is improved, so that a safe entry into the engagement zone of the traction sheave is ensured.

In all embodiments, steel cables are preferably used as tension members. In a further development of the invention, the ropes of a traction means are arranged alternately between S and Z impact. The risk of load-dependent twists is thereby minimized. An Gradzahligkeit the number of ropes used in a traction device improves this effect. Steel combines high tensile strength and fatigue strength with good adhesion to elastomers.

In a further development of the invention, the diameter of the individual ropes is between 1.5 mm and 8 mm, preferably between 1.8 and 5.5 mm, particularly preferably between 2 and 4 mm. In this diameter range, a particularly good ratio of minimum diameter of the traction sheave and high load capacity is given.

In a development of the invention, the side of the traction mechanism facing away from the traction sheave has a cover coating. In one development of the invention, the cover coating is formed from a flat textile, for example a fabric. With such a coating, both the friction and the wear resistance of the traction device can be improved.

The ratio of the second diameter of the sheathed tension member to the first diameter of the tension member is preferably between 1.2 and 1.6.

It is also essential on the traction mechanism drive according to the invention that at least the apex of the sheathed tension carrier rests on the surface of the corresponding groove of the traction sheave.

Further features, advantages and details of the invention will now be explained in more detail with reference to the drawing, which is a schematic embodiment of a traction mechanism drive:

In the single figure, a cross section is shown by a traction mechanism, which is particularly suitable for use in an elevator system. The traction mechanism drive has a traction means 1 and a traction sheave 9, through which the traction means 1 can be driven.

The traction means 1 has six tension members 2, which are encased by elastomeric material 11 to sheathed tension members 3. The tension members 2 are ropes made of steel. The sheathed tensile carriers 3 are - viewed in cross-section of the traction means - arranged in a plane next to each other in such spaced relation to each other, so that between two immediately adjacent sheathed tension members 3, a free space 6 is formed. The sheathed tensile carrier 3 are connected by a back layer 4 back to each other. The space 6 begins on the side facing away from the backsheet 4 and extends over one Level 12, which is formed by the centers 5 of the tension members 2 out. The diameter (d2) of the sheathed tension member 3 is 3.5 mm and the diameter (d1) uncoated, bare tension member 2 is 2.5 mm. The ratio of the second diameter (d2) of the sheathed tension member 3 to the first diameter (d1) of the tension member 2 is 1.4. The sheathing of the tension member 2 with elastomeric material is comparatively thin at 0.5 mm: this has the advantage that the sheathing material is only slightly stressed in shear and the elastomer material is not significantly fatigued. In addition, the forces of the traction disc can be transferred very well.

The sheath 3 of the tension members 2 has an outer contour facing the traction sheave 9, the cross section of which corresponds to a part-circular shape and has a radius R1 of 1.75 mm. The traction sheave 9 facing broad side of the traction means consisting of part circular forms, wherein the forming the partial circular sheathed steel cables engage in corresponding grooves 10 in the traction sheave 9. The grooves 10 have a contour which corresponds to a circular circle shape with the radius R2 of 1.85 mm. It is particularly important that the tension members 2 engage the grooves 10 of the traction sheave 9 without and in spite of their elastomer sheathing, at least 5%.

The sheathing of the reinforcement and the back layer 4 are made of PU. The ratio of diameter (d2) of the sheathed tension member (2) to the total thickness (D) of the traction means (1) is D = 0.95. The back layer 4 has a thickness c, where c is at its thinnest point ≦ 1 mm. The tension members 2 of the traction means 1 are spaced apart from one another such that the distance t of the centers 5 of the tension members 2 is 4.5 mm.

LIST OF REFERENCE NUMBERS (Part of the description)

1

traction means

2

tension members

3

jacketed tension member

4

backing

5

Center of the cross section of the tension member

6

free space

7

Sheath of the tension member

8th

Thickness of the sheathing of the tension member

9

traction sheave

10

Groove of the traction disc

11

elastomeric material

12

level

d1

Diameter of the tension member

d2

Diameter of the sheathed tension member

D

Thickness of the traction device

c

Thickness of the backsheet

t

Distance between the centers of second directly adjacent tensile carriers

R1

Radius of the sheathed tension member

R2

Radius of the groove of the traction disc

Claims (17)

1. Pulling means (1), especially for a lift installation, having tension members (2) which are sheathed by elastomer material to form sheathed tension members (3), wherein, in the cross section of the pulling means, the sheathed tension members (3) are arranged next to each other in one plane at such a distance from each other that there is a space (6) between two sheathed tension members (3), wherein the sheathed tension members (3) are connected at the rear by a back layer (4), characterized in that, beginning on the side facing away from the back layer (4), the space (6) extends at least beyond the central point (5) of the tension member, wherein the ratio of the second diameter (d2) of the sheathed tension member (3) to the first diameter (d1) of the tension member (2) is between 1.05 and 2.25, preferably between 1.2 and 1.6, and wherein the sheath (3) of the tension members (2) has an outer contour facing the traction sheave (10), the cross section of which corresponds to the shape of a partial circle.
2. Pulling means according to Claim 1, characterized in that the thickness of the sheath (3) of the tension members (2) is in a range of from 0.2 to 2 mm, preferably between 0.5 and 1 mm.
3. Pulling means according to Claim 1 or 2, characterized in that the sheath (3) is formed from an elastomer which differs from the elastomer of the back layer (4).
4. Pulling means according to at least one of the preceding claims, characterized in that the elastomer is preferably a polyurethane.
5. Pulling means according to at least one of the preceding claims, characterized in that the ratio of the diameter (d2) of the sheathed tension member (3) to the overall thickness (D) of the pulling means (1) is D ≤ 1.
6. Pulling means according to at least one of the preceding claims, characterized in that the back layer (4) has a thickness (c), c being ≤ half the thickness D of the composite rope (1) at the thinnest point of c.
7. Pulling means according to at least one of the preceding claims, characterized in that the tension members (2) of the pulling means (1) are spaced apart in such a way that the spacing (t) between the centers (5) of the tension members (2) is less than or equal to five times the diameter (d1) of the tension members (2) and is at least d1 + 1.5 mm.
8. Pulling means according to at least one of the preceding claims, characterized in that the back layer (4) has a profiled surface.
9. Pulling means according to at least one of the preceding claims, characterized in that each pulling means (1) has at least four tension members (2).
10. Pulling means according to at least one of the preceding claims, characterized in that the tension members (2) are ropes, preferably made of steel.
11. Pulling means according to Claim 10, characterized in that the ropes (2) have an alternate S and Z lay.
12. Pulling means according to at least one of the preceding claims, characterized in that there is an even number of tension members (2) per pulling means (1).
13. Pulling means according to at least one of the preceding claims, characterized in that the diameter of a tension member (2) is between 1.5 mm and 8 mm.
14. Pulling means according to at least one of the preceding claims, characterized in that the surface of the back layer has a top coating.
15. Pulling means according to Claim 14, characterized in that the top coating is formed from a sheet-like textile, e.g. a woven fabric.
16. Pulling-means drive, especially for a lift installation, comprising a pulling means (1) according to one or more of the preceding claims and at least one traction sheave, by means of which the pulling means can be driven, wherein each sheathed tension member (3) engages in a corresponding groove (10) of the traction sheave (9), wherein the elastomer back layer (4) is arranged on the side of the tension members (2) which faces away from the side which engages in the grooves (10) of the traction sheave (9), and wherein at least one tension member engages by at least 5% of the diameter (d1) thereof in the corresponding groove (10) of the traction sheave (9).
17. Lift installation, characterized in that it has a pulling-means drive according to Claim 16.

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