Travelling cable of an elevator, and an elevator
09944494 · 2018-04-17
Assignee
Inventors
Cpc classification
D07B1/025
TEXTILES; PAPER
D07B2801/10
TEXTILES; PAPER
D07B1/02
TEXTILES; PAPER
H01B11/22
ELECTRICITY
D07B1/22
TEXTILES; PAPER
D07B1/145
TEXTILES; PAPER
D07B2801/10
TEXTILES; PAPER
B66B9/00
PERFORMING OPERATIONS; TRANSPORTING
D07B1/162
TEXTILES; PAPER
International classification
B66B7/06
PERFORMING OPERATIONS; TRANSPORTING
D07B1/16
TEXTILES; PAPER
B66B9/00
PERFORMING OPERATIONS; TRANSPORTING
H01B7/18
ELECTRICITY
H01B11/22
ELECTRICITY
D07B1/14
TEXTILES; PAPER
B66B7/12
PERFORMING OPERATIONS; TRANSPORTING
B66B11/08
PERFORMING OPERATIONS; TRANSPORTING
D07B1/02
TEXTILES; PAPER
D07B1/04
TEXTILES; PAPER
Abstract
A travelling cable of an elevator, more particularly of a passenger transport elevator and/or freight transport elevator, includes a protective envelope, conductors for transmitting electrical energy and data between the elevator car and the elevator hoistway, and one or more load-bearing bearer parts of essentially the length of the travelling cable for fixing the travelling cable at its first end to the elevator car and at its second end to the elevator hoistway, and which bearer part includes glass-fiber reinforcements and/or aramid-fiber reinforcements and/or carbon-fiber reinforcements and/or polybenzoxazole-fiber reinforcements and/or polyethylene-fiber reinforcements and/or nylon-fiber reinforcements in a polymer matrix material. An elevator includes the travelling cable.
Claims
1. A travelling cable of an elevator, comprising: a protective envelope; conductors for transmitting electrical energy and data between an elevator car and an elevator hoistway; and load-bearing bearer parts of essentially the length of the travelling cable for fixing the travelling cable at a first end thereof to the elevator car and at a second end thereof to the elevator hoistway, wherein each bearer part is a composite structure and is composed of reinforcing fibers, wherein the reinforcing fibers are glass reinforcing fibers or aramid reinforcing fibers or carbon reinforcing fibers or polybenzoxazole reinforcing fibers or polyethylene reinforcing fibers or nylon reinforcing fibers, and wherein the reinforcing fibers are distributed in a polymer matrix material, wherein at least one bearer part of said bearer parts includes one or more optical fibers disposed inside, or essentially in a proximity of a surface of the composite structure of said at least one bearer part, wherein the composite structure of said at least one bearer part is completely non-metallic and wherein the reinforcing fibers of said at least one bearer part are straight and essentially unidirectional with a longitudinal direction of the traveling cable and are homogeneously distributed into the polymer matrix material of said at least one bearer part, wherein a plurality of said bearer parts are directly surrounded by a plurality of twisted-pair cables, and wherein the plurality of twisted-pair cables are directly surrounded by said conductors.
2. The travelling cable according to claim 1, wherein the polymer matrix material of each bearer part is a non-elastomer and the modulus of elasticity of the matrix material is at least 1.5 GPa.
3. The travelling cable according to claim 1, wherein the density of the reinforcing fibers of each bearer part is less than 4000 kg/m3 and/or the tensile strength of the reinforcing fibers is over 1500 N/mm2.
4. The travelling cable according to claim 1, wherein the reinforcing fibers of each bearer part are carbon fibers, glass fibers, aramid fibers or polymer fibers, or a number of different types of fibers.
5. The travelling cable according to claim 1, wherein the reinforcing fibers of each bearer part are a unidirectional reinforcement essentially in the longitudinal direction of the respective bearer part.
6. The travelling cable according to claim 1, wherein the one or more optical fibers extend inside the composite structure essentially from the first end of the travelling cable and come out essentially from the second end of the travelling cable, or makes one or more turns inside the respective bearer part and come out of the structure essentially from the first end or from the second end of the travelling cable.
7. The travelling cable according to claim 1, wherein at least one of the one or more optical fibers is a Fabry-Perot-type sensor fiber for the condition monitoring of the respective bearer part.
8. The travelling cable according to claim 1, wherein at least one of the one or more optical fibers is a sensor fiber, comprising a Bragg grating structure for the condition monitoring of the respective bearer part.
9. The travelling cable according to claim 1, wherein at least one of the one or more optical fibers is a sensor fiber, which functions as a Brillouin distributed fiber sensor for the condition monitoring of the respective bearer part.
10. The travelling cable according to claim 1, wherein at least one of the one or more optical fibers is a sensor fiber, in which fiber the time-of-flight of a light pulse is measured for the condition monitoring of the respective bearer part.
11. The travelling cable according to claim 1, wherein the one or more optical fibers is in the form of a fiber bundle, and wherein the fiber bundle extends inside the respective composite structure essentially from the first end of the travelling cable and comes out essentially from the second end of the travelling cable, or makes one or more turns inside the respective bearer part and comes out of the structure essentially from the first end or from the second end of the travelling cable.
12. The travelling cable according to claim 1, wherein the travelling cable is round in cross-section shape.
13. An elevator, comprising: an elevator car; a counterweight; one or more suspension ropes including a load-bearing composite part, the load bearing composite part including reinforcing fibers in a polymer matrix, the one or more suspension ropes connecting the elevator car and the counterweight to each other; and a mechanism configured to move the elevator car and/or the counterweight, the mechanism comprising a hoisting machine configured to move the suspension roping, wherein the elevator includes the travelling cable according to claim 1 for transmitting electrical energy and data between the elevator car and the elevator hoistway.
14. The elevator according to claim 13, wherein the elevator includes a mechanism configured to monitor the condition of the at least one bearer part which includes the one or more optical fibers by monitoring changes that have occurred in an optical property of the one or more optical fibers.
15. The elevator according to claim 13, wherein the travelling cable includes a mechanism configured to monitor the condition of the at least one bearer part that includes one or more optical fibers by monitoring changes that have occurred in an electrical property of the respective bearer part.
16. An elevator, comprising: an elevator car; a counterweight; one or more suspension ropes including a load-bearing composite part, the load bearing composite part including reinforcing fibers in a polymer matrix, the one or more suspension ropes connecting the elevator car and the counterweight to each other; and a mechanism configured to move the elevator car and/or the counterweight, the mechanism comprising a hoisting machine configured to move the suspension roping and including a rotating device and a traction device to be rotated, wherein the elevator includes the travelling cable according to claim 1 for transmitting electrical energy and data between the elevator car and the elevator hoistway.
Description
BRIEF DESCRIPTION OF THE FIGURES
(1) The invention will now be described in more detail in connection with its preferred embodiments, with reference to the attached drawings, wherein
(2)
(3)
(4)
(5)
DETAILED DESCRIPTION OF THE INVENTION
(6)
(7) In the embodiment presented in
(8) In the embodiments presented in
(9) The ropes of the suspension roping 3 can be suspended by bending around a rope pulley, which rope pulley does not need to be a driven rope pulley. As presented the elevator comprises a rope pulley 5 or rope pulleys in the proximity of the top end and/or the bottom end of the path of movement of the elevator car 1. For example, while supported on the rope pulley 5 the rope or ropes of the suspension roping 3 support the elevator car 1 and the counterweight 2. In the embodiments presented this is implemented with a 1:1 suspension, in which case the ropes of the suspension roping 3 are fixed at their first end to the elevator car 1 and at their second end to the counterweight 2. The suspension ratio can, however, be another, e.g. 2:1, but a 1:1 ratio is advantageous because, when the rope structure comprises a composite part in the manner specified, making a large number of bends is not advantageous owing to the space taken by the bends. Preferably the rope pulleys are non-driven rope pulleys, thus also the top parts of the elevator can be formed to be spacious. The rope pulleys are in the elevator hoistway S, in which case a separate machine room is not needed.
(10) The hoisting roping 4 can be different in its cross-section and/or in its material to the suspension roping 3. The structure of the ropes of the hoisting roping 4 can be optimized e.g. from the viewpoint of shearing force in the direction of the rope and of friction, whereas the structure of the ropes of the suspension roping 3 can be optimized from the viewpoint of the tensile strength and stiffness and lightness of the rope. The suspension roping 3 and the hoisting roping 4 can comprise one or more ropes, which comprise one or more force-transmitting parts of composite structure.
(11) The travelling cable T, e.g. cable of round cross-sectional shape or flat cable, intended for the electricity supply of the elevator car 1 and/or for data traffic is fixed at its first end to the elevator car 1, e.g. to the bottom part of the elevator car 1, and at its second end to a connection point on the wall of the elevator hoistway S, which connection point is typically at the point of the midpoint or above the midpoint of the height direction of the elevator hoistway. From the elevator car 1 the travelling cable leaves at first downwards and then turns upwards towards its fixing point of the second end forming a bottom loop in its bottom part, which bottom loop hangs freely in the elevator hoistway and moves in the hoistway S upwards or downwards along with the movement of the elevator car 1.
(12)
(13) The width of the aforementioned bearer part 10 is preferably greater than the thickness, e.g. the cross-section of the bearer part 10 can be of rectangular shape, as is presented in
(14) The aforementioned bearer part 10 can be fabricated e.g. in pultrusion by pulling reinforcements wetted with resin or prepreg reinforcements through a heated nozzle acting as a mould, in which the bearer part 10 receives its shape and the resin hardens. In this way good strength properties in the longitudinal direction of the travelling cable are obtained for the bearer part 10. The reinforcements can also be partly or fully wound around a preform functioning as the core material. In this way the stiffness properties of the bearer part 10 can be further adjusted by adjusting the winding angle of the reinforcements. The core material is preferably e.g. of PVC foam or urethane foam. Pultrusion is a continuous, highly-automated profile manufacturing method, which reaches a high production speed, preferably a production speed as high as 0.5-2 m/min, i.e. pultrusion is particularly suited to the manufacture of large series. Pultrusion products characteristically have a high reinforcement content and longitudinal alignment of the reinforcements. Owing to this, the axial mechanical properties are also high. The reinforcements are typically rover-type reinforcements.
(15) The bearer part 10 of the travelling cable T is a flexible member elongated in the longitudinal direction of the travelling cable T for receiving a load in essentially the longitudinal direction of the travelling cable T. The aforementioned bearer part is able to bear a significant part of the load exerted on the travelling cable in question, e.g. tensile stress in the longitudinal direction of the travelling cable caused by moving the elevator car 1 and the counterweight 2 according to the embodiment of
(16) According to the invention the width of the aforementioned bearer part 10 is preferably greater than the thickness. The width-thickness ratio of the bearer part 10 is preferably at least 2 or more, more preferably at least 4, or even 5 or more, or even 6 or more, or even 7 or more or even 8 or more.
(17) According to one embodiment of the invention, presented in
(18) The width of the aforementioned bearer part 10 according to the invention presented in
(19) According to the embodiment of the travelling cable T according to the invention, which embodiment is presented in
(20) The condition of the bearer part 10 of the travelling cable of an elevator is monitored by monitoring the condition of the sensor fibers, and if it is detected that a part of a sensor fiber has broken or the condition of it has fallen to below a certain predefined level, a need to replace or overhaul the travelling cable is diagnosed and travelling cable replacement work or travelling cable maintenance work is started. The condition of the bearer part 10 can also be monitored by measuring the time-of-flight of a light pulse in the sensor fibers of the different parts and by comparing the times-of-flight of the light pulses with each other and when the difference between the times-of-flight of the light pulses increases to above a predefined level, a need to replace or overhaul the travelling cable is diagnosed and travelling cable replacement work or travelling cable maintenance work is started. The condition monitoring device can be arranged to initiate an alarm if the time-of-flight of the light pulse does not fall within the desired value range or differs sufficiently from the measured values of the time-of-flight of the light pulse of other sensors being measured. The time-of-flight of the light pulse changes when a property that depends on the condition of a load-bearing part of the travelling cable, such as strain or displacement, changes. For example, owing to the breaking of reinforcing fibers the time-of-flight of the light pulse changes, from which change it can be deduced that the bearer part 10 is in poor condition.
(21) Preferably the means for monitoring the condition of the bearer part 10 comprises a condition monitoring device connected to the sensor fibers and to the reference fibers of the bearer part 10, which device comprises means, such as e.g. a computer comprising a laser transmitter, receiver, timing discriminator, a circuit measuring a time interval, a programmable logic circuit and a processor. The aforementioned means comprise one or more sensors, each of which sensors comprises e.g. reflectors, and a processor, which when they detect a change, e.g. in the time-of-flight of the light pulse in the sensor fiber, raise an alarm about excessive wear of the bearer part 10.
(22) The property to be observed can also be e.g. a change in the amount of light travelling through the bearer part 10. In this case light is fed into an optical fiber with a laser transmitter or with a LED transmitter from one end and the passage of the light through the bearer part 10 is assessed visually or by the aid of a photodiode at the other end of the fiber. The condition of the bearer part 10 is assessed as having deteriorated when the amount of light travelling through the bearer part 10 clearly decreases.
(23) In one embodiment of the invention an optical fiber functions as an optical Fabry-Prot-type sensor. A Fabry-Perot interferometer FPI comprises two reflective surfaces, or two parallel highly reflective dichroic mirrors, at the end of the fiber. When it hits the mirror a part of the light passes through and a part is reflected back. After the mirror the light passing through travels e.g. through air, after which it is reflected back from the second mirror. Some of the light has traveled a longer distance in a different material, which has caused changes in the properties of the light. Strain causes changes in e.g. the phase of the light. The light with changed properties interferes with the original light, after which the change is analyzed. After the lights have combined they end up in a receiver of a condition monitoring device of the elevator and in a signal-processing device. In the embodiment the strain of the fiber, and thus the condition of the bearer part 10, is assessed.
(24) In one embodiment of the invention an optical fiber, comprising Bragg gratings is used, i.e. the so-called Fiber Bragg Grating FBG method is applied in the condition monitoring of the rope. Periodic grating structures are made in a single-mode fiber for the FBG sensor, which grating structures reflect a certain wavelength of the light corresponding to the grating back. When light is conducted into the fiber, the wavelength of the light corresponding to the grating is reflected back. When strain is exerted on the grating structure, the refractive index of the fiber changes. Changing of the refractive index affects the wavelength of the light being reflected back. By monitoring changes in wavelength, a change in the strain exerted on the grating can be ascertained, and thus also the condition of the bearer part 10. There can be tens or hundreds of gratings by the side of the same fiber.
(25) In one embodiment of the invention a distributed sensor fiber based on Brillouin spectrometry is used as an optical fiber. Ordinary single-mode fiber or multimode fiber can be used as a sensor. The optical fiber functions as a distributed sensor, which can function as a sensor that is hundreds of meters long, which measures throughout its length and corresponds if necessary to thousands of point-form sensors. Backscattering of light occurs continuously as the light propagates in the fiber. This can be utilized by monitoring the strength of certain backscattering wavelengths. Brillouin scattering arises in the manufacturing phase in non-homogeneous points created in the fiber. By observing the wavelengths of the original and the scattered light signal the strain of the fiber, and thus the condition of the bearer part 10, is determined.
(26) The effect of temperature on strain measurements can be eliminated by, inter alia, using a reference fiber as an aid, which reference fiber is installed such that strain caused by the structure to be measured is not exerted on it.
(27) In one embodiment of the invention the bearer part 10 of the travelling cable comprises a part conducting electricity, preferably e.g. carbon-fiber reinforcement in a polymer matrix material. The condition monitoring arrangement comprises a condition monitoring device connected to the second end of the bearer part, near its fixing point, which is thus electrically conductive. The arrangement further comprises a conductor fixed to the electrically conductive, preferably metallic, first connection point of the bearer part 10, which conductor is also connected to the condition monitoring device. The condition monitoring device connects the bearer parts 10 and the conductors and is arranged to produce voltage between them. The condition monitoring device further comprises means for observing an electrical property of the circuit formed by the bearer parts 10 and the conductors. These means can comprise e.g. a sensor and a processor, which when they detect a change in an electrical property raise an alarm about excessive wear of the bearer part 10. The electrical property to be observed can be e.g. a change in the resistance or capacitance of the aforementioned circuit. The electrical property of a bearer part 10 comprising reinforcing fibers, more particularly carbon-fiber reinforcements, changes when the condition of the reinforcements deteriorates and when the strain of the bearer part increases.
(28) Structurally the aforementioned bearer part 10 of the travelling cable is preferably a composite structure, preferably a non-metallic composite structure, which comprises reinforcing fibers in a polymer matrix material. The reinforcing fibers are essentially evenly distributed in the matrix material, which surrounds the individual reinforcing fibers and which is fixed to them. The matrix material fills the areas between individual reinforcing fibers and binds essentially all the reinforcing fibers that are inside the matrix material to each other as an unbroken solid binder agent. In this case abrasive movement between the reinforcing fibers and movement between the reinforcing fibers and the matrix material is prevented. A chemical bond exists between, preferably all, the individual reinforcing fibers and the matrix material, one advantage of which is cohesion of the structure. For reinforcing the chemical bond, a sizing obtained as a result of the surface treatment of the reinforcing fibers can be between the reinforcing fibers and the matrix material, in which case the aforementioned bond to the fiber is formed via the sizing in question.
(29) The fact that the reinforcing fibers are in the polymer matrix material means that the individual reinforcing fibers and possible optical fibers are bound in the manufacturing phase to each other with the matrix material, e.g. with resin. With the method according to the invention, in pultrusion reinforcements wetted with resin or prepreg reinforcements are pulled through a heated nozzle acting as a mould, in which the piece receives its shape and the resin hardens. In this case there is resin in between the individual reinforcing fibers that are bound to each other. According to the invention, therefore, a large amount of reinforcing fibers in the longitudinal direction of the rope that are bound to each other are distributed in the matrix material, being also evenly distributed in the bearer part 10 of the travelling cable. The reinforcing fibers are preferably distributed essentially evenly in the matrix material such that the bearer part 10 of the travelling cable is as homogeneous as possible when viewed in the direction of the cross-section of the bearer part 10. In this way the reinforcement density does not vary greatly in the bearer part 10 of the travelling cable.
(30) The reinforcing fibers and possible optical fibers together with the matrix material form an unbroken bearer part 10, inside which large shape deformations do not occur when the rope is bent. The individual fibers of the bearer part 10 of the travelling cable are mainly surrounded with matrix material, but contacts between fibers can occur in places, e.g. because of pores in the matrix material. If, however, it is desired to reduce the random occurrence of contact between fibers, the individual fibers can be surface treated before the binding of individual fibers to each other. In the invention the individual fibers of the bearer part 10 of the travelling cable can comprise the material of the matrix material around them such that the matrix material is immediately against the fiber, but the thin surface treatment material of the fiber, e.g. a primer arranged on the surface of the fiber in the manufacturing phase to improve chemical adhesion to the matrix material, can be in between. The matrix material can comprise a basic polymer and, as a supplement, additives for optimizing the properties of, or for hardening, the matrix material. The matrix material is preferably of non-elastomer. The most preferred matrix materials are epoxy resin, polyester resin, phenolic resin or vinyl ester. The modulus of elasticity E of the matrix material is preferably over 1.5 GPa, more preferably over 2 GPa, even more preferably in the range 2-10 GPa, most preferably of all in the range 2.5-4 GPa.
(31) Preferably the aforementioned reinforcing fibers are non-metallic fibers, which have a high specific stiffness, i.e. ratio of the modulus of elasticity to density, and specific strength, i.e. ratio of strength to density. Preferably the specific strength of the reinforcing fibers of the bearer part 10 of the travelling cable in tension is over 500 (MPa/g/cm3) and the specific stiffness over 20 (GPa/g/cm3). Preferably the aforementioned reinforcing fibers are carbon fibers, glass fibers, aramid fibers or polymer fibers, e.g. polyethylene fibers, such as UHMWPE fibers, polybenzoxazole fibers or nylon fibers, which are all more lightweight than metal reinforcements. The reinforcing fibers of the bearer part 10 of the travelling cable can comprise one of these, e.g. just carbon fibers, or can be a combination of these fibers, e.g. carbon fibers and polybenzoxazole fibers, or can comprise at least one of these fibers. Most preferably the aforementioned reinforcing fibers are carbon fibers or polybenzoxazole fibers, which have a good specific stiffness and specific strength in tension and at the same time withstand very high temperatures. This is important in elevators because poor heat tolerance of the bearer part 10 of the travelling cable might be a safety risk.
(32) It is obvious to the person skilled in the art that in developing the technology the basic concept of the invention can be implemented in many different ways. The invention and the embodiments of it are not therefore limited to the examples described above, but instead they may be varied within the scope of the claims.