DE60015771T2 - PERMANENT FOR AN ELEVATOR - Google Patents

Description

TECHNICAL AREA

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

BACKGROUND THE INVENTION

One conventional Traction elevator system has a car, a counterweight, two or more the cab and the counterweight interconnecting Ropes, a traction sheave to move the ropes, and one Machine to turn the traction sheave on. The ropes are made of laid or twisted steel wire, and the pulley is made of cast iron. The machine can either be a gear machine or a gearless machine. A gear machine allowed the use of a higher engine Speed, which is more compact and less expensive, but extra Maintenance and space needed.

Even though conventional, Round steel cables and cast iron pulleys are very reliable and cost effective there are restrictions in their use. One such limitation is the traction forces between the ropes and the pulley. These traction forces can increase by the winding angle of the cables or by undercutting the grooves be increased in the pulley. Both techniques, however, reduce the durability of the ropes as Result of increased wear (winding angle) or increased Rope pressure (undercutting). Another way to increase traction is, formed from a synthetic material inserts in the Use grooves of the pulley. The inserts increase the coefficient of friction between the ropes and the sheave, being at the same time minimize the wear of the ropes and pulley.

Another limitation in the use of round steel cables is the flexibility and fatigue properties of round steel wire ropes. Elevator safety regulations today require that each steel cable has a minimum diameter d (d _min = 8 mm for CEN; d _min = 9.5 mm (3/8 ") for ANSI) and that the D / d ratio for traction elevators is greater than or equal to forty is (D / d ≥ 40), where D is the diameter of the sheave, which results in the pulley diameter D being at least 320 mm (380 mm for ANSI), the larger the sheave diameter D is, the larger it is torque required by the machine to drive the elevator system.

Another disadvantage of conventional round ropes is that the rope life is shorter the higher the rope pressure. Rope pressure (P _rope ) is generated when the rope moves over the sheave and is directly proportional to the tension (F) in the rope and inversely proportional to the sheave diameter D and the rope diameter d (P _rope ≈ F / (Dd)) , In addition, the shape of the pulley grooves, including such traction increasing techniques as undercutting the pulley grooves, further increases the maximum rope pressure to which the rope is subjected.

GB-A-2 134 209 discloses a flat rope for a winding machine, which a plurality of steel cables which are in a rubbery Material are included.

regardless In the above prior art, scientists and engineers work under the direction of the assignee's legal successor, more efficient and to develop more durable methods and devices for elevator systems drive.

EPIPHANY THE INVENTION

According to the present Invention is provided a tension member as claimed in claim 1 is. It has in agreement with the invention, a tension member for a lift an aspect ratio of greater than one, the aspect ratio is defined as the ratio the tension element width w to the thickness t (aspect ratio = w / t).

One principal feature of the present invention is the flatness of the tension element. The increase in aspect ratio results in a tension member that an engagement surface has, defined by the latitude dimension optimized to distribute the rope pressure. Therefore, the maximum pressure is in the tension member minimized. Furthermore can by increasing the aspect ratio relative to a round Rope that has an aspect ratio has one, the thickness of the tension element to be reduced, with a constant cross-sectional area of the tension element is maintained.

Further according to the present Invention the tension element a plurality of individual load bearing strands, strands and / or cables enclosed in a common layer of a sheath are. The coating layer separates the individual strands, Strands and / or cables and defines a Eingrifffläche to Interaction with a traction cable pulley.

Due to the design of the tension element, the rope pressure can be distributed more uniformly over the tension element. As a result, the maximum rope pressure is significantly reduced compared to one in a conventional manner with a rope provided elevator with a similar load bearing capacity. In addition, the effective rope diameter "d" (measured in the bending direction) for the equivalent load carrying capacity is reduced. Therefore, smaller pulley diameter "D" values can be achieved without a reduction in D / d ratio. In addition, minimizing the diameter D of the sheave allows the use of less expensive, more compact, high speed engines than the prime mover without the need for a transmission.

The strands, Strands and / or cables in the tension member of the invention are steel and organic fibers and can be provided in a number of combinations. The two materials can be separated and a single strands of steel and strands of organic fibers in one have common coat; the two materials can in a single strand combined, with a plurality of such strands is distributed in the common coat; the materials can be around each other wound in ordered arrangements within the common mantle be; and the organic fibers may happen to be in the common shell be distributed, with steel strands are also distributed in it.

each said combinations provides for a flexible, flat hybrid tension member with strengths and Advantages of flat tension elements with steel strands or flat tensile elements with organic fibers are not available. Benefits of each material are unique to steel: nondestructive Testing opportunities; high heat resistance; low elongation. And for organic fibers: low weight and high strength; not prone to Corrosion. The creation of a tension element that uses both steel as also uses organic fibers effectively, with load between the is divided into two leads to a tension element with significantly improved properties. The present invention provides several embodiments that correspond to the two Allow materials that "load to share, "what a consideration of the load carrying capacity each of the types of materials requires; the long-term bending fatigue resistance the individual materials; to achieve the elongation of each material and rope tracking stability such synergistic benefits.

The The foregoing and other objects, features and advantages of the present invention Invention will be understood in the light of the following detailed description, their exemplary embodiments, as illustrated in the accompanying drawings, more apparent.

SHORT DESCRIPTION THE DRAWINGS

It Reference is now made to the drawings, wherein like Elements in the several figures are numbered the same:

1 Figure 3 is a perspective view of a traction drive elevator system in which the tension member of the invention operates;

2 Figure 3 is a schematic cross-section of a first embodiment of a flexible, flat hybrid tension member of the invention;

3 Figure 3 is a schematic cross-section of a second embodiment of a flexible, flat hybrid tension member of the invention;

4 Fig. 12 is a schematic cross-section of a third embodiment of a flexible, flat hybrid tension member of the invention;

5 Figure 3 is a schematic cross-section of a fourth embodiment of a blended, flexible, flat tension member of the invention;

6 Fig. 10 is a graphic representation of a modulus of elasticity of a tension member of the invention; and

7 Figure 3 is a graphic representation of the strength of a tension member of the invention.

BEST MODE TO EXECUTE THE INVENTION

In 1 is a traction elevator system 12 illustrated. The elevator system 12 has a cabin 14 , a counterweight 16 , a traction drive 18 and a machine 20 on. The traction drive 18 has a tension element 22 that the cabin 14 and the counterweight 16 connects, and a traction cable pulley 24 on. The tension element 22 acts with the pulley 24 together, allowing a rotation of the pulley 24 the tension element 22 and thereby the cabin 14 and the counterweight 16 emotional. The machine 22 acts with the pulley 24 together to the pulley 24 to threaten. Although as a transmission machine 20 As illustrated, it should be noted that this configuration is for illustrative purposes only and the present invention may be used with geared or gearless machines.

The invention provides a flexible, flat, hybrid material tension member having better properties than flexible, flat, single-material tension members. It should be noted that not all possible blends of load bearing materials provide a synergistic result in the process created deliver. Rather, a careful analysis of structural load bearing properties is needed to balance the load exerted between the types of load bearing materials and to obtain better properties as well as excellent tension element tracking stability.

Referring to 2 a first embodiment of a flexible, flat hybrid tension member of the invention is schematically illustrated in cross-section. The tension element 22 has a common urethane or other polymer shell 26 on. Steel load bearing material is in with 28 marked areas, whereas organic load bearing material as 30 is identified. As one of ordinary skill in the art will appreciate, the load bearing material is relatively uniform across the width of the tension member 22 spaced. It is preferable to use two steel strands 28 Side by side at a central point of the tension element 22 to balance the tracking from side to side. Symmetry is important on both sides of a longitudinal centerline of the tension member to ensure stable tracking of the tension member to a pulley.

The organic fibers 30 are illustrated as having a larger cross-section than the steel strands 28 but this is not necessary. Rather, it is the question of which weight design is desired and which heat resistance is desired, as well as similar parameters. A mathematical calculation feasible within the skill of one of ordinary skill in the art is then performed to determine the amount of organic fiber to be used and the amount of steel strands to be used. The calculations are used to ensure that the load is shared between the various strands in the flat tension member, allowing the benefits and properties of each to be utilized. It is also important that the axial stiffness of the tension member be such that, for any given applied load, both types of strands share the elastic response of the tension member. The twist and the structure of these two types of strand can be chosen such that this load distribution is made possible. The strands, in turn, are not limited in size, number or distribution (apart from tracking) to allow this result, nor is it necessary to use an equal number of strands of organic fiber and steel strands. What is important is that the properties of the two strand types are balanced with respect to the desired properties of the tension element so that these desired properties can be achieved. For any desired result, more than one way of laying out the strands and dimensions, etc., is possible. It is noted that a distribution is important to facilitate a tracking aspect of the tension member, and one of the more easily achievable distribution schemes for proper tracking is a uniform distribution of strand types across an axial centerline of the tension member.

One Parameter to be preferably controlled is bending. It is preferable that steel strands prevent organic strands Bend fail, leaving nondestructive Test method used can be for integrity to determine the tension element. Such methods include an electrical Resistance or magnetic flux leakage.

In a further embodiment of the invention, referring to 3 , is every strand of the tension element 22 of hybrid nature. Shown is a tension member in cross section, wherein an organic fiber material is in a ring 32 around a core 34 made of steel. Although the tension member is illustrated with material types in only one kind, it will be understood that the organic fiber material may constitute the core using steel for the ring. It should also be noted that not all of the strands used in the embodiment need to use the same core material. One or more of the strands may be steel as a core 34 while one or more of the strands may use organic fibers as the core. The twist and structure of each strand around the ring and around the core affect the properties of the entire tension element, and this must be taken into account. One of ordinary skill in the art will be aware of how to calculate the various possible twists and design to arrive at the desired properties of the entire tension member. The degree to which elastomer penetration into the individual strands is desired should also be noted with respect to the position and size of the strands used. If the positions selected for the strands are strand-to-strand contact, fretting must also be considered. In a preferred construction for the embodiment, "s" and "z" strand constructions are used in equal numbers across the axial centerline of the tension member.

In 4 The invention is a further alternative embodiment illustrated. The figure is an enlarged view of only two strands 38 to illustrate the structure of each strand. In this embodiment, each strand is 38 composed of several strands, eg nine (eight by one), and each strand is of hybrid nature. The strands 40 in the drawing are shown to be a central organic wire 42 and eight steel wires 44 that are positioned around it, to have. Six of these strands then become a central strand 46 positioned around a hybrid strand 38 to build. It is understandable that the arrangement of steel wires 44 and the organic fibers 42 can be reversed. Similar calculations as mentioned in the previous embodiments must be made for this embodiment, such calculations being within the skill of those of ordinary skill in the art. Hybrid strands are also advantageous in that the specific construction of the strands can vary for specific purposes. For example, if a crown pulley (not shown) is used in a particular elevator system in which the tension member is used to enhance tracking, the strands that run close to or directly over the crown will be subject to greater stress than other strands in the tension member , The hybrid strands can be tailored to handle the higher load.

Referring now to 5 Yet another embodiment of the invention is illustrated. 5 is an enlarged view showing only two strands. It will be understood that the embodiment may include more strands. In this embodiment, steel strands 50 with preferably seven wires each in a pattern of six around one and are not directly hybrid strands. Rather, the tension element 22 hybrid as it is in the common wrapping material 28 Surrounding the strands, single organic fibers 52 having. The fibers 52 are preferably oriented parallel to the major axis of the tension member and over the material 28 distributed. The stiffness of the steel strands 50 This embodiment is controlled by the stiffness of the steel wires, with the organic fibers providing their own rigidity. The material 28 in this embodiment, as in the previous embodiments, it is preferably constructed of polyurethane.

• E₁₁ = longitudinales FFR-Modul
• E_11f1 = longitudinales Modul von Faser 1
• E_11f2 = longitudinales Modul von Faser 2
• E_m = Matrixmodul
• V_f1 = Volumenprozent von Faser 1
• V_f2 = Volumenprozent von Faser 2
• V_m = Volumenprozent von Matrix 3

For all embodiments described hereinbefore, the modulus of elasticity of the tension member can be increased by increasing the volume percent of steel used therein. As those skilled in the art will appreciate, module calculations are based on the "rule of mixtures", ie: e 11 = U f1 e 11f1 + V f2 e 11f2 + V m e m in which:

• E ₁₁ = longitudinal FFR module
• E _11f1 = longitudinal modulus of fiber 1
• E _11f2 = longitudinal modulus of fiber 2
• E _m = matrix module
• V _f1 = volume percent of fiber 1
• V _f2 = volume percent of fiber 2
• V _m = volume percent of matrix 3

The change in Young's modulus is in 6 to see graphically.

A calculation of a tensile strength of an exemplary tensile member of the invention as a function of the steel / organic fiber (eg, Kevlar) content within the common enclosure of the tensile member, ie, the polyurethane coating in a preferred embodiment, is disclosed in U.S. Pat 7 graphically, wherein the volume percentage of steel / kevlar to the common sheathing material is maintained at 60% by volume, but the percentage of steel and kevlar relative to each other is varied.

The exact curve change point in the graph is 24% steel and 16% kevlar 29 , (The value would be for kevlar 49 vary.) To the right of the 24/16 point Kevlar dominates the strength curve, and on the left steel dominates the strength curve. Steel fails at 2.0% elongation, whereas Kevlar fails at 3.6% elongation. When steel dominates, failure of the steel due to elongation causes the Kevlar to become overloaded and fail. However, when Kevlar dominates, steel failure at 2.0% elongation does not affect Kevlar failure, which holds up to 3.6% elongation.

• V_S = Volumenprozentanteil von Stahldrähte
• V_k = Volumenprozentanteil von Kevlar
• σ_s = Zugfestigkeit von Stahl
• σ_k = Zugfestigkeit von Kevlar

At the transition point of 24/16, the steel retains sufficient strength in the tension member for operational use of an elevator system which employs such a tension member after the Kevlar material has deteriorated, failed, or been destroyed. To obtain this result for different volume percentages of strand material to shell material, the equation is: V S ≥ (σ k / σ s ) V k in which

• V _S = volume percentage of steel wires
• V _k = volume percentage of kevlar
• σ _s = tensile strength of steel
• σ _k = tensile strength of kevlar

Even though preferred embodiments have been shown and described, various modifications and replacements are performed on it, without departing from the spirit and scope of the invention. Accordingly, it is understandable that the present invention by way of illustrations and not of restrictions has been described.

Claims (8)

Tension element ( 22 ) for providing a lifting force to a cabin of an elevator system, comprising: a plurality of load bearing elements ( 28 . 30 ); and an envelope ( 26 ) substantially enveloping the plurality of load bearing members and having an aspect ratio greater than 1, defined as a cross-sectional width to thickness of the tension member, characterized in that the load bearing members comprise steel and organic fiber load bearing members. A tension member for providing a lifting force to a cab of an elevator system according to claim 1, wherein said plurality of load bearing members comprise a plurality of individual steel load bearing members (10). 28 ) and a plurality of individual organic fiber load bearing elements ( 30 ) having. A pulling member for providing a lifting force to a car of an elevator system according to claim 1, wherein said plurality of load bearing members comprise individual hybrid strands ( 38 ) having both steel and organic fiber material therein. A pulling member for providing a lifting force to a car of an elevator system according to claim 3, wherein the strands comprise: a core ( 34 ) from steel; and a ring ( 32 ) made of organic fiber. A pulling member for providing a lifting force to a car of an elevator system according to claim 3, wherein the strands comprise: a core ( 34 ) of organic fiber; and a ring ( 32 ) from steel. Tension element for providing a lifting force to a car of an elevator system according to claim 3, wherein the strands ( 38 ) a plurality of strands ( 40 ), which then consist of a hybrid of steel wires ( 44 ) and organic fiber ( 42 ) are constructed. A pulling member for providing a lifting force to a cab of an elevator system according to claim 3, wherein said steel load bearing member is in the form of a plurality of individual strands ( 50 ) and the organic fiber load bearing elements ( 52 ) in the envelope ( 26 ) are distributed. Tension element for providing a lifting force to a car of an elevator system according to claim 7, wherein the organic fiber load bearing elements ( 52 ) parallel to a longitudinal axis of the tension element ( 22 ) are oriented.