WO2022262982A1

WO2022262982A1 - A guide shoe arrangement and an elevator utilizing the guide shoe arrangement

Info

Publication number: WO2022262982A1
Application number: PCT/EP2021/066432
Authority: WO
Inventors: Tuukka Korhonen; Tero Hakala
Original assignee: Kone Corporation
Priority date: 2021-06-17
Filing date: 2021-06-17
Publication date: 2022-12-22

Abstract

An elevator and a guide shoe arrangement (30) for guiding an elevator car (11) or a counterweight (17) along a guide rail section, the guide shoe arrangement comprising at least one guide rail section (12) and at least one guide shoe. The 5 longitudinal guide rail section (12) comprises three guide surfaces (33, 34, 35) comprising homogeneous electrically conducting material for generating eddy currents in the presence of a variable magnetic field. The guide shoe (20) for receiving guide surfaces of the guide rail section (12) comprises three electromagnets (36, 37, 38) arranged so that the magnetic axis of each 10 electromagnet is arranged essentially perpendicular to the each facing guide surface (33, 34, 35). Each electromagnet (36, 37, 38) is configured to generate a variable magnetic field facing the guide surface (33, 34, 35) of the guide rail section for inducing eddy currents to the guide surface while being energized so that an air gap (39) is established between the guide shoe (20) and the guide 15 surfaces of the guide rail section (12) by the magnetic field co-acting with said eddy currents.

Description

A GUIDE SHOE ARRANGEMENT AND AN ELEVATOR UTILIZING THE GUIDE SHOE ARRANGEMENT Field of the invention

The invention concerns in general the technical field of elevators. The invention concerns especially, however, not exclusively, a guide shoe arrangement and an elevator utilizing the guide shoe arrangement.

Background

Typical elevators comprise an elevator car which is adapted to move in elevator shaft along a vertical trajectory. The movement of the elevator car is defined by guide rails. Elevator cars have guides shoes, such as sliding guide shoes or guide rollers, which meet the guide rails to guide movement of the elevator car. Also, elevator counterweight can be guided by vertical guide rails. Often the elevator is provided with own guides rail for the elevator car and the counterweight. The guide rails run in the vertical direction from the bottom to the top of the shaft and they are mounted to vertical hoistway structures, such as walls. They can consist of plurality of guide rail sections placed end-to-end on top of each other. Guide rail sections are fixed to the hoistway structures by means of fixing members, such as brackets. A typical guide rail has a T-shaped cross-sectional profile.

As is known, friction forces are present between the guide shoes and the guide rails. In case of sliding guide shoes, they are in the form of sliding friction and in case of guide rollers rotational friction. Such friction forces cause energy losses, impairing energy efficiency of elevator system. Friction losses also cause material wear of the respective components.

Summary

An objective of the present invention is to provide a guide shoe arrangement with which mechanical contact between the guide rail and the guide shoe can be avoided or at least minimized. The objectives of the invention are reached by a guide shoe arrangement and an elevator as defined by the respective independent claims.

According to a first aspect, the invention relates to a guide shoe arrangement, e.g. a levitating shoe arrangement, for guiding an elevator car or a counterweight along a guide rail section. The guide shoe arrangement comprises at least one guide rail section and at least one guide shoe. The longitudinal guide rail section comprises three guide surfaces comprising homogeneous electrically conducting material for generating eddy currents in the presence of a variable magnetic field. The guide shoe for receiving guide surfaces of the guide rail section comprises three electromagnets arranged so that the magnetic axis of each electromagnet is arranged essentially perpendicular to the each facing guide surface of the guide rail section, and each electromagnet is configured to generate a variable magnetic field facing the guide surface of the guide rail section for inducing eddy currents to the guide surface while being energized so that an air gap is established between the guide shoe and the guide surfaces of the guide rail section by the magnetic field co-acting with said eddy currents.

In one embodiment of the invention the guide shoe arrangement comprises a power unit configured to energize the electromagnets.

In one embodiment of the invention each electromagnet comprises a separate power unit configured to energize the said electromagnet.

In one embodiment of the invention the power unit comprises a controller configured to adjust frequency and/or amplitude of the variable magnetic field.

In one embodiment of the invention the guide shoe comprises a gap sensor arranged to measure a gap between an electromagnet and the facing guide surface.

In one embodiment of the invention the guide shoe comprises three gap sensors, one for each gap between each electromagnet and facing guide surface. In one embodiment of the invention the power unit is configured to adjust frequency and/or amplitude of the variable magnetic field based on measurement data of the gap sensor.

In one embodiment of the invention the guide rail section comprises an essentially T-shaped cross-sectional profile comprising a lateral base member for fixing to a vertical shaft structure, such as to a shaft wall, a central member extending from the center of the base member, and three guide surfaces, e.g. two parallel guide surfaces and a front guide surface therebetween.

In one embodiment of the invention the central member comprises a front part having the guide surfaces, the front part being made of homogeneous electrically conducting material.

In one embodiment of the invention the guide shoe comprises a housing with a base for receiving the guide surfaces of the guide rail, e.g. the central member of the guide rail, wherein the housing comprises three electromagnets arranged in connection with the base and adapted for facing the three guide surfaces of the guide rail, respectively, such that magnetic axis of each electromagnet is arranged essentially perpendicular to the facing guide surface of the guide rail.

In one embodiment of the invention the base comprises three glide surfaces adapted for facing the three guide surfaces of the guide rail, respectively, each glide surface configured to enclose the respective electromagnet such that it forms an auxiliary glide bearing between the guide surface and the electromagnet.

According to a second aspect, the invention relates to an elevator comprising the guide rail arrangement according to the invention. The elevator comprises an elevator shaft, an elevator car movable in the shaft, an elevator guide rail, comprising plurality of guide rail sections placed end to end on top of each other and fixed to a vertical shaft structure, at least one guide shoe attached to an elevator car or to a car sling or to a counterweight and adapted for guiding elevator car or counterweight movement along an elevator guide rail while being energized. In one embodiment of the invention the elevator comprises the counterweight and the elevator car and the counterweight are suspended by hoisting ropes.

In one embodiment of the invention the elevator comprises elevator hoisting machine comprising electrical motor and a traction sheave engaging with the hoisting ropes.

In one embodiment of the invention the elevator further comprises a second elevator guide rail, comprising plurality of guide rail sections placed end to end on top of each other and fixed to a vertical shaft structure to the opposite side of the car or the counterweight, and a second guide shoe attached to the same side of the elevator car or the car sling or the counterweight as the second elevator guide rail and adapted for guiding elevator car or counterweight movement along the second elevator guide rail while being energized.

The present invention introduces new kind of guide arrangement for elevator car and/or counterweight when compared to the solutions of the prior art. The solution of the invention is useful for reducing friction and, consequently, energy losses and wearing of the components of the elevator system. This is especially advantageous in high-rise elevators and elevators travelling with high speed.

Various other advantages will become clear to a skilled person based on the following detailed description.

The expression "a plurality of” refers herein to any positive integer starting from two, e.g. to two, three, or four.

The terms "first", "second" and “third” do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

The exemplary embodiments of the present invention presented herein are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used herein as an open limitation that does not exclude the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. The novel features which are considered as characteristic of the present invention are set forth in particular in the appended claims. The present invention itself, however, both as to its construction and its method of operation, together with additional objectives and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

Brief description of the Figures The embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

Figure 1 presents schematically a simplified view of an elevator according to one embodiment of the invention,

Figure 2 presents schematically a simplified side view of an elevator according to one embodiment of the invention, and

Figure 3 presents, as a cross section, a guide rail section according to one embodiment of the invention.

Detailed description of some embodiments

The present invention introduces new kind of guide arrangement for an elevator car and/or a counterweight. The guide arrangement comprises guide rail sections and compatible guide shoes. Instead of mechanical sliding or rolling contact, the present invention is based on non-contact levitation between the guide rail and the guide shoe. Figure 1 shows a simplified schematic view of an elevator. The elevator comprises an elevator car 11 and a counterweight 17 which are configured to be moved in the vertical direction in a shaft 10. For the sake of clarity, many parts of the elevator, such as end buffers for the elevator car 11 , have been omitted in figure 1. The elevator car 11 is connected to the counterweight 17 via a hoisting member 13. The hoisting member 13 can be, for example, a steel wire, a belt, such as a toothed belt or a flat belt, a carbon fiber rope or a coated rope. The elevator can comprise several hoisting members 13. The elevator car 11 and the counterweight 17 are connected to each other in such a way that they move to opposite directions in respect of each other. The elevator is further provided with a motor 14. The motor 14 is preferably an electric motor. The motor 14 drives a sheave (not shown). The sheave can be connected to the motor 14 either directly or via a gear. As the sheave rotates, the hoisting member 13 moves and the elevator car 11 and the counterweight 17 are moved. In the example of figure 1 , each end of the hoisting member 13 is fixed to the upper end of the shaft 10. The elevator car 11 is provided with two pulleys, of which only one pulley 15 is shown in figure 1. In the example of figure 1 , the pulleys are arranged below the elevator car 1 . The hoisting member 13 is engaged with the pulleys, which are configured to rotate freely about a rotation axis. The counterweight 17 is provided with a pulley 16 which is engaged with the hoisting member 13. Also, the pulley 16 of the counterweight 17 is configured to rotate freely about a rotation axis. The sheave, the pulleys 15, 16 and the hoisting member 13 form the roping system of the elevator.

It should be noted that figure 1 shows only an example of a roping system of an elevator, and the hoisting member 13 could be arranged in many alternative ways. For example, the elevator car 11 could be provided with a single pulley. The counterweight 17 could be provided with more than one pulleys. A first end of the hoisting member 13 could be attached to the elevator car 11 and a second end of the hoisting member 13 could be attached to the counterweight 17. The hoisting member 4 could be guided around the sheave of the motor 14 twice.

In the example of figure 1 , the motor 14 is arranged in the shaft 10. The elevator is thus a machine-room-less elevator. However, the elevator could also be provided with a machine room located above the shaft 10 and the motor could be arranged in the machine room.

The elevator further comprises guide rails 2, 12. Guide rails run in the vertical direction in the elevator shaft 10. The guide rails 2, 12 guide the vertical movement of the elevator car 11 and the counterweight 17. Also, the safety gear of the elevator cooperates with the guide rails and the clamping jaws of the safety gear close around the guide and stop an over speeding car. The elevator of figure 1 comprises a pair of guide rails 2 that guide the counterweight 17 and another pair of guide rails 12 that guide the elevator car 11 . Typically, guide rails, preferably two of them, can consist of plurality of longitudinal guide rail sections, e.g., having a T-shaped cross-sectional profile, placed end to end on top of each other and fixed to a vertical shaft structure, such as to a shaft wall or a shaft frame. The guide rails are normally disposed at opposite sides of the car. Guide shoes are attached to an elevator car, a car sling and or a counterweight, at the opposite sides of it. The guide shoes are arranged to meet the guide rails and thus to guide elevator car movement along the guide rails.

In the example of Figure 1 , the guide rail 2, 12 can be attached to the walls of the shaft 10 via the arms of the T-shaped profile, while the side surfaces of the stem function as guide surfaces for the car 11 or the counterweight 17. The guide rail 2, 12 is typically assembled by connecting short segments.

Figure 2 presents schematically a simplified side view of an elevator according to one embodiment of the invention. In this view the elevator car 11 comprises four guide shoes 20 which are adapted to be guided by the guide rails 12. the guide shoes are attached in this example to the side of the elevator car, on top and bottom part of the side of the elevator car and on two sides of the elevator car. The guide rails 12 are attached to the wall 21 , 22 or other structure in the elevator shaft.

The solution of the invention can be used for example in the above-described elevator environment. In the solution of the invention, the guide shoe arrangement comprises at least one guide rail section and at least one guide shoe. The longitudinal guide rail section comprises three guide surfaces comprising homogeneous electrically conducting material for generating eddy currents in the presence of a variable magnetic field. The guide surfaces may be electrically conducting surface, such as of aluminum or stainless steel. The guide shoe for receiving guide surfaces of the guide rail section comprises three electromagnets arranged so that the magnetic axis of each electromagnet is arranged essentially perpendicular to the each facing guide surface of the guide rail section, and each electromagnet is configured to generate a variable magnetic field facing the guide surface of the guide rail section while being energized so that an air gap is established between the guide shoe and the guide surfaces of the guide rail section when the magnetic field co-acts with the eddy currents generated into the guide surface. The guide shoe is arranged to be close to the guide surfaces to enable establishing a magnetic engagement between the guide shoe and the guide surface of the guide rail by magnetic field generating means such as an electromagnet. The electromagnet may comprise a winding or a coil into which magnetic field generating current may be injected, that is, to operate as magnetic field generating means. The electromagnet may be used to generate an alternating or at least varying magnetic field, for example, by injecting alternating current to the coil. The electromagnet may further comprise, for example, ferromagnetic material as used in typical way in electromagnets and/or magnetic circuits.

The guide shoe arrangement may be controlled by the elevator control unit, another control unit or controller, that is, being at least communicatively coupled to the elevator control unit.

The guide shoe may be arranged in an operating position in which the magnetic field generated in the guide shoe affects or penetrates or extends the guide surfaces of the guide rail to generate eddy currents therein, that is, the levitating guide shoe is arranged close to the guide surface. The magnetic field may thus be utilized to establish an air gap between the levitating guide shoe and the guide surfaces and, thus, prevent or at least minimize said two parts becoming in contact with one another. The force causing the levitation of the guide shoe arrangement is based on eddy currents in the guide surfaces of the guide rail acting with the magnetic field produced by the levitating guide shoe.

Principle of a guide arrangement is illustrated in Figure 3 in which a cross section of a guide rail section is presented. In this example guide arrangement, each T- profile guide rail section consists of a lateral base member 30 for fixing to a vertical shaft structure, such as to a shaft wall, and a central member 31 extending from the center of the base member 30. The central member 31 comprises a front part 32 which has three guide surfaces 33, 34, 35. At least the front part 32 is made of homogeneous electrically conducting material, such as aluminum or stainless steel. Also, other part of the guide rail section can be made from the same material. Two of the guide surfaces 33, 35, e.g. parallel guide surfaces, are at the opposite sides of the front part 32 in parallel with each other. The third guide surface 34 is a front guide surface extending perpendicularly between the parallel guide surfaces 33, 35. The guide shoe 20 can comprise a housing (not shown) with a base for receiving the guide surfaces 33, 34, 35 of the central member 31 of the guide rail section. In the housing of the guide shoe, associated with the base there are three electromagnets 36, 37, 38 adapted for facing the three guide surfaces 33, 34, 35, respectively, such that magnetic axis of each electromagnet is arranged perpendicular to the facing guide surface, respectively. In the example of Figure 3, the guide surface 33 faces the electromagnet 36, the guide surface 34 faces the electromagnet 37 and the guide surface 35 faces the electromagnet 38.

As described above, each electromagnet is configured for generating a variable magnetic field at the facing guide surface while being energized. This means that variable magnetic field will generate eddy currents at the guide surfaces. Eddy currents co-acting with the variable magnetic field will cause thrust forces between the electromagnets and the facing guide surfaces, causing levitation effect therebetween. Such a levitation effect can be even self-adjustable in the sense that thrust forces will increase automatically when gap 39 between the electromagnet and the facing guide surface decreases.

In one embodiment of the invention the guide shoe comprises a power unit configured for energizing the electromagnets. According to an embodiment, same power unit will supply all three electromagnets simultaneously such that all electromagnets are connected in series or in parallel to a common supply line. According to an alternative embodiment, each electromagnet comprises a separate power unit configured for energizing the electromagnet in question.

The power unit can comprise or be connected to a controller for controlling power supply to the electromagnet(s), such as a microcontroller, microprocessor, programmable logic circuit, analog circuit etc. According to an embodiment, the controller is configured to adjust frequency and/or amplitude of the variable magnetic field. This way thrust forces between electromagnets and guide surfaces may be actively controlled.

According to one embodiment of the invention, the guide shoe comprises a gap sensor or is connected to a gap sensor. In one embodiment of the invention the guide shoe comprises three gap sensors or is connected to three gap sensors, the gap sensors adapted to measure a gap between an electromagnet and the respective facing guide surface. In embodiment of the invention the controller of the power unit is configured to adjust frequency and/or amplitude of the variable magnetic field based on measurement data of the gap sensor.

According to one embodiment, the guide shoe, housing of the guide shoe and/ or a base of the guide shoe comprises three glide surfaces adapted for facing the three guide surfaces of the guide rail, respectively. Each glide surface encloses the respective electromagnet such that it forms an auxiliary glide bearing between the guide surface and the electromagnet. This can mean that the glide bearing will prevent damaging of electromagnet if elevator car moves when the guide shoe is de-energized.

The elevator may comprise an elevator control unit for controlling the operation of the elevator. The elevator control unit may be a separate device or may be comprised in the other components of the elevator such as in or as a part of the electrical drive. The elevator control unit may also be implemented in a distributed manner so that, e.g., one portion of the elevator control unit may be comprised in the electrical drive and another portion in the elevator car. The elevator control unit may also be arranged in distributed manner at more than two locations or in more than two devices. In one embodiment of the invention the elevator control unit is configured to control the power units supplying power to the electromagnet(s).

The elevator control unit or other control unit or controller of the system may comprise one or more processors, one or more memories being volatile or non volatile for storing portions of computer program code and any data values and possibly one or more user interface units. The mentioned elements may be communicatively coupled to each other with e.g. an internal bus.

The processor of the elevator control unit or other control unit or controller is at least configured to implement some functionality of the present invention. The implementation of a solution of the invention may be achieved by arranging the processor to execute at least some portion of computer program code stored in the memory causing the processor, and thus the elevator control unit, to implement one or more method steps as described. The processor is thus arranged to access the memory and retrieve and store any information therefrom and thereto. For sake of clarity, the processor herein refers to any unit suitable for processing information and control the operation of the elevator control unit, among other tasks. The operations may also be implemented with a microcontroller solution with embedded software. Similarly, the memory is not limited to a certain type of memory only, but any memory type suitable for storing the described pieces of information may be applied in the context of the present invention.

The embodiments of the invention described herein before in association with the figures presented and the summary of the invention may be used in any combination with each other. At least two of the embodiments may be combined together to form a further embodiment of the invention.

The specific examples provided in the description given above should not be construed as limiting the applicability and/or the interpretation of the appended claims. Lists and groups of examples provided in the description given above are not exhaustive unless otherwise explicitly stated.

Claims

1. A guide shoe arrangement (30) for guiding an elevator car (11 ) or a counterweight (17) along a guide rail section, the guide shoe arrangement comprising at least one guide rail section (12) and at least one guide shoe: wherein the longitudinal guide rail section (12) comprises three guide surfaces (33, 34, 35) comprising homogeneous electrically conducting material for generating eddy currents in the presence of a variable magnetic field, and wherein the guide shoe (20) for receiving guide surfaces of the guide rail section (12) comprises three electromagnets (36, 37, 38) arranged so that the magnetic axis of each electromagnet is arranged essentially perpendicular to the each facing guide surface (33, 34, 35), and wherein each electromagnet (36, 37, 38) is configured to generate a variable magnetic field facing the guide surface (33, 34, 35) of the guide rail section for inducing eddy currents to the guide surface while being energized so that an air gap (39) is established between the guide shoe (20) and the guide surfaces of the guide rail section (12) by the magnetic field co-acting with said eddy currents.

2. An arrangement according to claim 1 , wherein the guide shoe arrangement comprises a power unit configured to energize the electromagnets (36, 37, 38).

3. An arrangement according to claim 1 or 2, wherein each electromagnet comprises a separate power unit configured to energize the said electromagnet (36, 37, 38).

4. An arrangement according to any previous claim, wherein the power unit comprises a controller configured to adjust frequency and/or amplitude of the variable magnetic field.

5. An arrangement according to any previous claim, wherein the guide shoe comprises a gap sensor arranged to measure a gap between an electromagnet (36, 37, 38) and the facing guide surface (33, 34, 35).

6. An arrangement according to claim 5, wherein the guide shoe comprises three gap sensors, one for each gap between each electromagnet (36, 37, 38) and facing guide surface (33, 34, 35).

7. An arrangement according to claim 5 or 6, wherein the power unit is configured to adjust frequency and/or amplitude of the variable magnetic field based on measurement data of the gap sensor.

8. An arrangement according to any previous claim, wherein the guide rail section (12) comprises an essentially T-shaped cross-sectional profile comprising a lateral base member (30) for fixing to a vertical shaft structure, such as to a shaft wall (21 , 22), a central member (31 ) extending from the center of the base member (30), and three guide surfaces (33, 34, 35), e.g. two parallel guide surfaces (33, 35) and a front guide surface (34) therebetween.

9. An arrangement according to claim 8, wherein the central member (31 ) comprises a front part (32) having the guide surfaces (33, 34, 35), the front part being made of homogeneous electrically conducting material.

10. An arrangement according to any previous claim, wherein the guide shoe comprises a housing for receiving the guide surfaces (33, 34, 35) of the guide rail (21 ), e.g. the central member (31 ) of the guide rail, wherein the housing comprises three electromagnets (36, 37, 38) arranged in connection with the housing and adapted for facing the three guide surfaces (33, 34, 35) of the guide rail, respectively, such that magnetic axis of each electromagnet (36, 37, 38) is arranged essentially perpendicular to the facing guide surface (33, 34, 35) of the guide rail.

11. An arrangement according to claim 10, wherein the guide shoe or the housing of the guide shoe comprises three glide surfaces adapted for facing the three guide surfaces (33, 34, 35), respectively, each glide surface configured to enclose the respective electromagnet (36, 37, 38) such that it forms an auxiliary glide bearing between the guide surface (33, 34, 35) of the guide rail and the electromagnet (36, 37, 38).

12. An elevator comprising the guide rail arrangement (30) according to any one of claims 1 - 11 , comprising an elevator shaft (10), an elevator car (11 ) movable in the shaft, an elevator guide rail of the guide rail arrangement, comprising plurality of guide rail sections (12) placed end to end on top of each other and fixed to a vertical shaft structure, at least one guide shoe (20) of the guide rail arrangement attached to an elevator car (11 ) or to a car sling or to a counterweight (17) and adapted for guiding elevator car (11 ) or counterweight (17) movement along an elevator guide rail while being energized.

13. An elevator according to claim 12, wherein the elevator comprises the counterweight (17) and wherein the elevator car (11 ) and the counterweight (17) are suspended by hoisting ropes (13).

14. An elevator according to claim 12 or 13, wherein the elevator comprises elevator hoisting machine comprising electrical motor (14) and a traction sheave engaging with the hoisting ropes (13).

15. An elevator according to any claim 12 - 14, wherein the elevator further comprises a second elevator guide rail, comprising plurality of guide rail sections (21 ) placed end to end on top of each other and fixed to a vertical shaft structure to the opposite side of the car (11 ) or the counterweight (17), and a second guide shoe attached to the same side of the elevator car or the car sling or the counterweight as the second elevator guide rail and adapted for guiding elevator car or counterweight movement along the second elevator guide rail while being energized.