KR100697742B1 - Tension Member For An Elevator - Google Patents

Abstract

The hybrid material tensioning member 22 for an elevator or other interpersonal transport system 12 uses an individual or combination of organic fibers 30 and steel material 28 as load carrying components. Several embodiments are disclosed.

Elevator, interpersonal transportation system, hybrid material tension member, load carrying parts, organic fiber, steel material

Description

Tension Member For An Elevator}

The present invention relates to elevator systems, and more particularly to tension members for such elevator systems.

Conventional towing elevator systems include a passenger compartment, counterweight, two or more ropes interconnecting the passenger compartment and the counterweight, a towing pulley for moving the rope, and a device for rotating the towing pulley. The rope is formed of laid or twisted steel wire, and the pulley is formed of cast iron. The device may or may not have gears. If the device is equipped with a gear, it is possible to use a high speed motor, while the device is compact and inexpensive, while requiring additional maintenance and space.

While conventional round steel ropes and cast iron pulleys are very reliable and economical, their use is limited. One of the limitations is the traction between the rope and the pulley. This traction may be increased by increasing the wrap angle of the rope or cutting the lower part of the pulley groove. However, as a result of increased wear (lap angle) or increased rope pressure (lower cutting), both techniques reduce the rope's durability. Another way to increase traction is to use a liner made of synthetic material in the pulley groove. The liner increases the coefficient of friction between the rope and the pulley while minimizing the wear of the rope and the pulley.

Other limitations when using round steel ropes are the fatigue properties of flexible and round steel wire ropes. Elevator safety protocols currently require that each steel rope have a minimum diameter d (d _min = 8 mm according to CEN and d _min = 9.5 mm (3/8 ") according to ANSI) and the diameter of the pulley In this case, the D / d ratio of the traction elevator is required to be 40 or more (D / d ≧ 40). As a result, the diameter D of the pulley is at least 320 mm (380 mm according to ANSI). The larger is, the greater is the torque required of the device to drive the elevator system.

F/Dd)에 반비례한다. 또한, 도르래 홈의 하부를 절삭하는 것과 같은 그러한 견인력 증대 기술을 포함하여, 도르래 홈의 형상도 로프가 받는 최대 로프 압력을 증가시킨다.Another drawback of conventional round ropes is that the higher the rope pressure, the shorter the life of the rope. P _rope is generated as the rope moves over the pulley, which is directly proportional to the rope's tension (F) and pulley diameter D and rope diameter d (P _rope).

Inversely proportional to F / Dd). In addition, the shape of the pulley grooves also increases the maximum rope pressure the rope receives, including such traction enhancement techniques as cutting the bottom of the pulley grooves.

Despite the technology, scientists and engineers strive to develop more efficient and durable methods and devices for driving elevator systems under the applicant's assignee's direction.

According to the present invention, an elevator tension member has an aspect ratio of greater than 1, which is defined as the ratio of the width w to the thickness t of the tension member (aspect ratio = w / t).

The main feature of the present invention is that the tension member is flat. As the aspect ratio increases, the interface of the tension member, consequently defined by its width, is optimized to disperse the rope pressure. Therefore, the maximum pressure in the tension member is minimized. In addition, when compared with the round rope having an aspect ratio of 1, increasing the aspect ratio may reduce the thickness while maintaining a constant cross-sectional area of the tension member.

Also in accordance with the present invention, the tension member comprises a plurality of individual load carrying cords, strands and / or wires encased in a common coating layer. This coating layer separates each cord, strand and / or wire and defines an interface that mates with the pulley.

If the tensioning member is configured in this way, the rope pressure can be more evenly distributed throughout the tensioning member. As a result, the maximum rope pressure is significantly reduced as compared with conventional rope elevators with equivalent load carrying capacity. In addition, the effective rope diameter 'd' (measured in the bending direction) for equivalent load bearing capacity is also reduced. Therefore, the pulley diameter 'D' may be made smaller without reducing the D / d ratio. In addition, by minimizing the diameter D of the pulley, it is possible to use a cheaper and smaller high-speed motor as a drive device that requires no gear box.

The cords, strands and / or wires in the tension members of the invention are preferably various combinations of steel and organic fibers. These two materials may be kept separate and may include separate steel cords and organic fiber cords in a common coating. The two materials may be combined into a single cord and the plurality of cords are dispersed in a common coating. The material may be layered in an orderly arrangement in a common coating, and the organic fibers may optionally be dispersed in the coating with the steel cord dispersed in the common coating.

Each combination provides a flexible flat hybrid tension member with strength and benefits not found in a flat tension member of steel cord or a flat tension member of organic fibers. In view of the advantages of each material, the steel has nondestructive testing ability, high heat resistance, low stretch, and the organic fibers are low weight, high strength and corrosion resistance. By using both steel and organic fibers effectively to produce a tension member that shares the load therebetween, the tension member will have significantly improved properties. The present invention provides several embodiments of load sharing between two materials, which necessitate consideration of the load carrying capacity of each material. The resistance to prolonged bending fatigue conditions of each material, the extensibility of each material and the tracking stability of the belt achieve this synergistic benefit.

The foregoing and other objects, features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments, as shown in the accompanying drawings.

Referring now to the drawings, like elements are denoted by like reference numerals in the several views.                 

1 is a perspective view of an elevator system with a pull drive in which the tensioning member functions internally;

2 is a schematic cross-sectional view of a first embodiment of the flexible flat hybrid tension member of the present invention.

3 is a schematic cross-sectional view of a second embodiment of the flexible flat hybrid tension member of the present invention.

4 is a schematic cross-sectional view of a third embodiment of the flexible flat hybrid tension member of the present invention.

5 is a schematic cross-sectional view of a fourth embodiment of the flexible flat hybrid tension member of the present invention.

6 is a graph showing the elastic modulus of the tension member of the present invention.

7 is a graph showing the strength of the tension member of the present invention.

A traction elevator system 12 is shown in FIG. The elevator system 12 includes a passenger compartment 14, a counterweight 16, a traction drive 18 and a machine 20. The traction drive 18 includes a tension member 22 and a traction pulley 24 interconnecting the passenger compartment 14 and the counterweight 16. The tension member 22 is engaged with the pulley such that rotation of the pulley 24 moves the tension member 22 to move the passenger compartment 14 and the counterweight 16. The machine 20 is engaged with the pulley 24 to rotate the pulley 24. Although shown as a geared machine 20, it should be noted that this configuration is for illustration only, and that the geared or inorganic geared machine may be used in the present invention.

The present invention provides a flexible flat tension member made of a hybrid material having superior properties as compared to a flexible flat tension member made of a single material. Not all possible combinations of load carrying materials provide synergistic results to the tensioning member produced. Rather, a careful analysis of the structural load carrying capacity is required to balance the load on each load carrying material and to obtain excellent tracking stability as well as good properties of the tension member.

2, there is schematically shown a cross section of a first embodiment of a flexible flat hybrid tension member of the present invention. Tensile member 22 includes a conventional urethane or other polymer jacket 26. The steel load carrying material is located in the area indicated by 28, while the organic load carrying material is identified by 30. Those skilled in the art will appreciate that the load carrying material is relatively evenly spaced over the width of the tension member 22. In order to balance tracking from side to side, it is preferable to provide two side-by-side steel cords 28 at the center position of the tension member 22. To ensure stable tracking of the tension member on the pulley, it is important that both sides are symmetrical about the longitudinal centerline of the tension member.

The organic fiber 30 is shown as having a larger cross-sectional area than the steel cord 28 but need not be. Rather, how much weight grade is required and how much heat resistance is required is a problem with similar parameters. In order to determine the amount of organic fibers and the amount of steel cord to be used, mathematical calculations are carried out within the skill level of the person skilled in the art to do this. This calculation is employed to ensure that the load is shared between the various cords in the flat tension member so that the respective advantages and characteristics are utilized. It is also important that the axial stiffness of the tension member is such that, at any given load, the tension member reacts elastically so that both types of cords share the load. The twist and structure of these two types of cords can be chosen to enable this load sharing. These cords are not limited in size, number or dispersion (other than for tracking) so that these results are possible, and the same number of organic fiber cords and steel cords are not required to be used. What is important is that two kinds of cord properties are balanced with those of the desired tension member so that such desired properties can be achieved. For each desired result, one or more ways of locating codes, sizing, etc. may be employed. Dispersion is important to facilitate tracking of the tension member, and one of the more easily achieved dispersion methods for proper tracking is to distribute the cord evenly with respect to the axial centerline of the tension member.

One parameter that is good for control is bending. When bent, it is preferable that the steel cord breaks before the organic cord so that non-destructive testing can be used to determine whether the tension member is integrity. Such methods include electrical resistivity or magnetic flux leakage.

Referring to Fig. 3, another embodiment of the present invention is shown wherein each cord of tension member 22 is in itself complex. A cross section of a tension member is shown in which an organic fiber material is located in an annular 32 portion around a steel core 34. This tension member is shown in one direction only in the kind of material, but it should be understood that steel is used in the annulus and the organic fiber material may constitute the core. It will also be appreciated that not all cords used in the examples need to use the same core material. One or more cords may employ steel as core 34, while one or more other cords may employ organic fibers as core 34. The twist and structure of each cord at the annular level and at the core level will affect the overall tensile member properties and should therefore be taken into account. One skilled in the art knows how to calculate various possible twists and structures to achieve the desired properties of the overall tension member. The degree to which the penetration of an elastomer into each cord is required must also be considered with regard to the location and size of the cord used. Fretting should be considered when there is contact between the cord at the location chosen for the cord. As a preferred structure as this embodiment, the same number of "s" and "z" cord structures are employed with respect to the axial centerline of the tension member.

4 illustrates another embodiment of the present invention. This figure is an enlarged view of only two codes 38, to show the configuration of each code. In this embodiment, each cord 38 consists of several strands, for example nine (one in the middle and eight surrounding it), each strand being complex in itself. Strand 40 in the figure is shown having a central organic wire 42 and eight steel wires 44 positioned around it. These six strands are positioned around the central strand 46 to form the hybrid cord 38. It will be appreciated that the position of the steel wire 44 and the organic fibers 42 may be reversed. Similar calculations must be made for this embodiment as in the above-described embodiment, within the skill level of those skilled in the art. Hybrid code is also beneficial in that the particular configuration of the code may vary depending on the particular purpose. For example, in a special elevator system where tension members are used to improve tracking, when crowned pulleys (not shown) are used, cords placed directly above or near the crown may be tension members. You will receive more load than any other cord in. Hybrid cords can be tailored to bear more load.

Referring to Fig. 5, another embodiment of the present invention is shown. 5 is an enlarged view showing only two codes. It will be appreciated that this embodiment may include more code. In this embodiment, the steel cord 50 itself is preferably provided with seven wires in six patterns each around one, which are not straight hybrid cords. Rather, the tension member 22 is complex because it includes the individual organic fibers 52 in a common coating material 28 surrounding the cord. The fibers 52 are preferably oriented parallel to the tension member major axis and distributed throughout the material. The stiffness of the steel cord 50 of this embodiment is controlled by the stiffness of the steel wire, while the organic fibers provide their own stiffness. The material 28 of this embodiment is made of polyurethane, as in the case of the embodiments described above.

In all the embodiments described above, the elastic modulus of the tension member can be increased by increasing the volume percent of the contained steel. As will be appreciated by those skilled in the art, coefficient calculations are based on "rules of mixtures."

_{E 11 = U f1 E 11f1 +} V f2 E 11f2 + V m E m

here,

E ₁₁ = longitudinal FFR factor

E _11f1 = longitudinal modulus of fiber 1

E _11f 2 = longitudinal modulus of fiber 2

E _m = matrix coefficient

V _f1 = percent by volume of fiber 1

V _f2 = percent by volume of fiber 2

V _m = percent volume of matrix 3

The change in elastic modulus is graphically shown in FIG.

Calculation of the tensile strength of an exemplary tension member of the present invention is shown graphically in FIG. 7 as a function of the steel / organic fiber (eg Kevlar) content in a common coating of the tension member, for example polyurethane, in the preferred embodiment. It is noted that the volume percentage of steel / Kevlar relative to the common coating material is maintained at 60v / o (volume percent), while the percentage of steel and Kevlar relative to each other is varied.

The exact inflection point on the graph is 24% of the river and 16% of the Kevlar (29). (This value changes for Kevlar (49).) To the right of 24/16, the Kevlar in the intensity curve Dominate, and to the left, the steel prevails in the strength curve. Steel breaks at 2.0% strain, while Kevlar breaks at 3.6% strain. Where the steel prevails, if the steel breaks due to strain, the kevlar is also overloaded and broken. Where Kevlar predominates, however, the breakage of steel at 2.0% strain does not affect the breakage of Kevlar retained up to 3.6% strain.

At the inflection point of 24/16, the steel retains sufficient strength in the tension member so that the elevator system using the tension member functions even after the Kevlar material is degraded, broken or destroyed. In order to achieve this result for different volume percent cord materials relative to the coating material, the following equation is required.

_k/

_s)V_k V _s ≥ (

_k /

_s ) V _k

here,

V _s = percent volume of steel

V _k = percent volume of Kevlar

_s = 강의 인장 강도

_s = tensile strength of steel

_k = 케블라의 인장 강도

_k = tensile strength of Kevlar

While the preferred embodiments have been shown and described, various modifications and substitutions may be made without departing from the spirit and scope of the invention. Accordingly, it should be understood that the invention is described in an illustrative manner, not a limitation.

Claims (8)

Tension member for providing transportation to the boarding compartment of the elevator system, A plurality of steel and organic fiber load carrying members, And a coating having an aspect ratio greater than 1, which defines a substantial contour of the plurality of load carrying members and is defined as the width of the cross section with respect to the thickness of the tension member. The tension member according to claim 1, wherein the plurality of load carrying members comprises a plurality of individual steel load carrying members and a plurality of individual organic fiber load carrying members. The tension member of claim 1, wherein the plurality of load carrying members include individual hybrid cords having both steel and organic fiber materials therein. 4. The tension member as recited in claim 3, wherein the cord comprises a core of steel and an annular portion of organic fibers. 4. The tension member as recited in claim 3, wherein the cord comprises a core of organic fibers and an annular portion of steel. 4. The tension member as recited in claim 3, wherein the cord comprises a plurality of strands of hybrid wires of steel and organic fibers. 4. The tension member according to claim 3, wherein the steel load carrying member is in the form of a plurality of individual cords and the organic fiber load carrying member is dispersed in the coating. 8. The tension member as recited in claim 7, wherein the organic fiber load carrying member is oriented parallel to the longitudinal axis of the tension member.

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