ES2211130T5 - TRACTION ELEVATION SYSTEM THAT USES A FLEXIBLE AND FLAT CABLE, AND A PERMANENT MAGNET MACHINE. - Google Patents

Abstract

A lifting system (10) having a cabin (12; 72) arranged inside an elevator box (23), including the lifting system: a cable (20; 82) connected to the cabin (12; 72 ), the cable having a width w, a thickness t measured in the direction of bending and an aspect ratio, defined as the ratio between the width w with respect to the thickness t, greater than one; and a machine (22; 78) connected with the cable (20; 82) to drive the cable by traction between the cable and the machine, and thereby drive the cabin (12; 72) along the elevator housing (23), in which the machine (22; 78) includes a rotor (44; 92) partly formed by permanent magnets (48; 94).

Description

Tensile lift system that uses a flexible and flat cable, and a permanent magnet machine.

The present invention relates to systems lifting and more specifically to the lifting systems that They use machines with motors that have permanent magnets.

A typical traction lift system includes a cabin and a counterweight arranged in a box of elevator or elevator, a plurality of cables that interconnect the cab and counterweight and a machine that has a tractor pulley coupled with the cables. The cables, and thus the cabin and the counterweight, are driven by pulley rotation tractor. The machine and its associated electronic equipment, together with the peripheral components of the lifting system, such as a regulator, are housed in a machine room located in the top of the box the elevator.

A recent trend in the industry of lifting systems is the removal of the machine room and place the various components and equipment of the lifting system in The elevator box. An example is the JP patent 4-50297, which describes the use of a machine located between the space for the movement gives the cabin and a wall of the elevator box. Another example is the State patent United 5,429,211, which describes the use of a machine located in the same position, but it has a motor with a rotor of the type of disk. This configuration uses the flatness of such a machine to minimize the space required for the machine in the box elevator. This machine described also uses permanent magnets in the rotor in order to improve machine efficiency. These guys of machines, however, are limited to those cases in which that the required performance and speeds are relatively low.

A possible solution to apply to such machines for lifting systems with higher load requirements or higher speed systems, is to increase the diameter of the rotor. This solution, however, is not practical due to the restrictions or limitations of elevator box space. Another solution, described in the PCT Application, PCT / FI98 / 00056 (WO98 / 32685) is to use a machine with two engines and a tractor pulley interspersed between the two engines. This solution, however, also exceeds the limitations of elevator box space and requires the existence of a separate machine room, located at the top of the box  of the elevator, to house the machine.

The patent WO-A-9943602, which constitutes the prior art according to article 54 (3) EPC, describe a lifting system of the belt lift type. Other lifting system is also known from the patent EP-A-0688735.

Hannover Messe: Neue Idee von Contitech-Hubgurte für Aufzüge. '' Contitech, Pages 14-16, 04.98 exposes a lifting belt system for elevators in which a plurality of steel cables are arranged in parallel and surrounded with rubber to form a belt lift that has a relationship between dimensions greater than one.

The document JP-A-7117957 exposes a device elevator comprising an elevator constituted by a rotor motor exterior arranged in the upper section of an elevator box. In particular it exposes an elevator system that has a cabin and a counterweight arranged inside an elevator box defined by the walls of the elevator box, including the system elevator:

a cable clutch with the cab and the counterweight to suspend the cabin and the counterweight; and a machine ready inside the elevator box and that includes a traction sheave and an engine that has a rotor and a stator and also includes a air gap between the rotor and the stator, the pulley being traction connected directly to the rotor for rotation Simultaneously and attached to the cable to drive the cable through traction between the cable and the traction sheave and in this way drive the cabin through the elevator box, in which the rotor is formed partly of permanent magnets.

Despite the technique cited above, the scientists and engineers under the direction of the Applicant they are working to develop the lifting systems that efficiently use the available space and comply with the speed and load capacity requirements in a wide range of applications in lifting systems.

In accordance with a first aspect of the present invention, a lifting system such as the claimed in claim 1.

Thus, a lifting system according with an aspect of the invention includes a machine that has a rotor that includes permanent magnets and a flat cable coupled with machine.

The flat cable, as used here, is defined to include cables that have an aspect ratio, defined as the ratio between width w and thickness t, greater than one A more detailed description of an example of such Cables is included in the US Patent Application, Serial Number 09 / 031,108, assigned jointly, entitled "Member tensioner for a lifting system ", presented on February 2 of 1998, published as US Patent 6,401,871.

An advantage of the present invention is the Machine size required to meet the requirements of speed and load capacity. The combination of efficiency Improved machine and torque reduction provided by the flat cable, it results in a very machine compact that can be mounted within the restrictions of space of an elevator box, without adversely affecting the operation of the lifting system. This allows the machine be placed in positions that were previously impracticable

Another advantage is a reduction in the consumption of lifting system energy using the present invention. He flat cable results in a coupling surface, defined by the width value, which is optimized to distribute the cable pressure Therefore, the maximum pressure is minimized inside the cable In addition, by increasing the ratio of aspect with respect to that of a round cable, which has a aspect ratio substantially equal to one, the thickness of the cable can be reduced while keeping the surface of a cable cross section. Minimize cable thickness results in a smaller pulley diameter tractor unit, which in turn reduces the torque value on the machine, Decrease engine size and can eliminate the need for gear drive In addition, the smaller pulley diameter results in an increase in the speed of rotation of the engine, which It also increases the efficiency of the machine.

In a specific embodiment, the machine with permanent magnets is combined with a flat cable that includes a plurality of load carrying members and a sheath that surrounds the load carrying members and is made from polyurethane. In another configuration, the load carrying members are steel cables made from very thin wires whose diameters are 0.25 mm or less. The use of a cover made from
Polyurethane allows the outer surface of the cable to be optimized for tensile strength.

An advantage of this specific embodiment is the minimum risk of heat damage to the case and members cable charging carriers, due to the use of a machine that It has a motor with permanent magnets. In a conventional engine of induction, many of the heat losses occur in the rotor. This heat loss is carried directly to the cables through of the case. For cables made of materials other than steel, which are more sensitive to temperature, exposure to such a source of heat can lead to cable degradation. By using a machine that has a rotor with magnets permanent the main source of heat losses occurs, not However, through the stator and not through the rotor. For the so much, since there is no direct step between the stator and the wires, these are not exposed to the primary source of heat and the risk of heat-related degradation of cable materials It is minimized. In addition, the increased efficiency of the machine with permanent magnets reduces all heat generated and therefore reduces the heating of the cables.

The foregoing and other features and advantages of the present invention will become more apparent to the light of the following detailed description of the embodiments copies of that, as shown in the attached drawings, in which:

Figure 1 is a perspective view of a lifting system according to the present invention.

Figure 2 is a perspective view of a alternative embodiment of the present invention.

Figure 3 is a sectional side view of a machine and the cables used in the embodiments of the Figures 1 and 2.

Illustrated in Figure 1 there is a system of elevation 10 in accordance with the present invention. System lift 10 includes a cabin 12, a pair of guide rails 14 of the cabin, a counterweight 16, a pair of guide rails 18 of the counterweight, a plurality of cables 20 that interconnect the cab 12 and the counterweight, and a traction machine 22 connected to the cables 20. Cab 12 and counterweight 16 are interconnected to move in unison and in opposite directions along the box of the elevator 23.

Cab 12 includes a frame 24 and a pair of investment pulleys 26 (only one of which is shown in the Figure 1) arranged on opposite sides of the bottom of the Cab frame 24. Investment pulleys 26 define some connection means between the cabin 12 and the cables 20 and allow the cables 20 pass under the booth 12 such that the booth 12 It's hung down.

The counterweight 16 includes an investment pulley 28 arranged on top of the counterweight 16. This pulley of inversion 28 defines connection means between the counterweight 16 and the cables 20. As a result of the wiring arrangement shown in figure 1, both the cabin 12 and the counterweight 16 are connected by wires in a 2: 1 value arrangement with respect to the machine 22.

Machine 22 is located between the path of displacement of the cabin 12 and a wall 30 of the box of the elevator 23. Machine 22 is shown in more detail in Figure 3. Machine 22 includes a motor 32 having an axis 34 and a tractor pulley 36. Engine 32 includes a frame 38, bearings 40, a stator 42 and a rotor 44. The tractor pulley 36 is arranged in the end of the shaft 34 and defines a coupling surface 46 for cables 20. The rotor 44 is arranged with a fixed ratio with respect to axis 34 and includes a plurality of permanent magnets 48 arranged radially into the stator 42, such shape that defines a radial air gap 50 or air gap between the rotor 44 and the stator 42. The use of permanent magnets 48 Increase efficiency and minimize engine size 32.

The cables 20 that interconnect the cabin 12 and The counterweight 16 are flexible flat cables. As shown in the Figure 3, there are three separate flat cables 20 coupled with the machine 22. Each flat cable 20 includes a plurality of members 52 cargo carriers surrounded by a sheath 54. The plurality of 52 load bearing members support tensile loads in the cables 20. The sheath 54 provides a retention layer for the 52 load-bearing members, while also defining a coupling surface 56 for flat cable 20. Traction between the flat cable 20 and the machine 22 is the result of the interaction between the coupling surface 56 of the cables 20 and the complementary coupling surface 46 of the machine 22. Although shown in Figure 3 with three flat cables 20, which have each of them four members 52 cargo carriers, can use different numbers of flat cables and different numbers of load carrying members within each cable, such as a embodiment that has a single flat cable or a flat cable that have a single load bearing member.

The load bearing members are manufactured from steel cables. In order to provide enough flexibility to the cable, the cable is manufactured from wires of steel or fiber having a diameter of 0.25 mm or less.

A suggested material for the case is the polyurethane. Polyurethane provides the required durability while also increasing the tensile value between the cable plane and machine. Although this material is recommended, they can other materials also be used. For example, a cover can be used made from neoprene or rubber.

The use of flexible flat 20 cables minimizes the size of the tractor pulley 36 and for this reason minimizes the torque value over motor 32 and increases the speed of rotation of engine 32. By combining these characteristics of the flat cables 20 with the characteristics of the machine 22 of permanent magnets, the size of the motor 32 and the machine 22 can be mounted within the available space between the cabin 12 and wall 30 of the elevator housing. Another advantage is that the higher turning speed further increases engine efficiency 32 and can eliminate the need for a gearbox.

The use of a rotor 44 that has magnets permanent 48 also reduces the amount of heat lost through of rotor 44 compared to conventional engines of induction. As shown in Figure 3, the rotor 44, the pulley tractor unit 36 and cables 20 are in direct contact. This contact direct results in the heat generated in rotor 44 being carried to cables 20. For conventional induction motors, the rotor is responsible for approximately one third of the heat losses However, for rotors that use magnets permanent, the heat loss through the rotor is minimal and the main source of heat loss in such engines is through of the stator. As shown in Figure 3, in embodiments of according to the present invention there is no direct passage between the stator 42 and cables 20. Therefore, the effects are minimized on wires 20 of engine heat loss 22. This is especially significant for cables that have a sheath manufactured from non-metallic materials, such as the polyurethane, which are more susceptible to heat degradation than steel

The lifting system 10 illustrated in the Figure 1 includes a cabin 12 that is hung from below. The figure  2 illustrates another embodiment. In this embodiment, a cabin 57 includes a pair of investment pulleys 58 located in the part top of cabin 57 in a manner known as hanging overhead. In conventional lifting systems, the provisions of hung on top with wires are less desirable in some applications due to the need to provide space additional top, for the lifting system. In the configuration shown in Figure 2, however, the effects of a cabin 57 hung above is minimized as a result that a machine can be used with the present invention Small and small pulleys. Therefore, a cabin 57 hung by above using the Applicant's invention requires less space above it and it is more practical.

In another alternative (not shown), the cabin it can be directly connected by cables to the machine in such a way that pulleys are not required in the cabin. Also, even if you are not illustrated, the machine can be located above the path of the cabin. Although in this particular embodiment you should enable the required space at the top for the machine, the combination of a machine with permanent magnets and the flexible flat cables will minimize the value of this enabling of space.

The embodiments illustrated in the Figures 1-3 all correspond to lifting systems that They have machines without gears. Although the invention is particularly advantageous because it increases the scope of application of gearless machines, it should be noted that the invention can also be used in machines with gears in applications private individuals

Although the invention has been shown and described regarding exemplary embodiments thereof, it should be understood by experts in the field that can be done to it several changes, omissions and additions, without departing from the object of the invention as defined in the claims.

Claims (7)

1. An elevator system (10) that has a cabin (12) and a counterweight (16) arranged inside a box of elevator (23); defined by the walls of the elevator shaft (30), including the elevator system: a cable (20) attached to the cabin (12) and to the counterweight (16) to suspend the cab and the counterweight, including  the cable one or more load drag members (52), in which the load drag members (52) are formed of threads of steel having a diameter of 0.25 mm or less, and a coating (54), in which the coatings are formed by non-material metal; Y a machine (22) arranged inside the box of lift and that includes a traction sheave (36) and a rotor (44) and a stator (42), in which the rotor (44) is separated in the direction radial inward of the stator (42), and which also includes a air gap (50) between the rotor (44) and the stator (42), the traction sheave (36) connected directly to the rotor (44) for simultaneous rotation and clutched to the cable (20) to drive the cable by traction between the cable and the traction sheave, and in this way drive the cabin (12) by the elevator box (23), wherein the rotor (44) is partly formed by permanent magnets  (48); in which the cable (20) has a width w, a thickness t measured in the direction of flexion, and a ratio of dimensions, defined as the ratio of the width to the thickness t, greater than one. 2. The lifting system according to the claim 1, wherein the coating (54) is formed by a polyurethane material. 3. The lifting system according to the claim 1 or 2, wherein the machine (22, 78) does not have gears 4. The lifting system according to any previous claim, wherein the machine (22) is arranged between the cabin travel space (12) and a wall (30) of the elevator box (23). 5. The lifting system according to any previous claim, wherein the cable (20) is clutched with a pair of pulleys (26) arranged on the cabin (12) so that the cable (20) passes under the cabin. 6. The lifting system according to any of claims 1 to 4, wherein the cable (20) is clutch to a pulley (58) arranged on the top of the cabin. 7. The lifting system according to any previous claim, wherein the drag members of load (62) are enclosed within a lining (54) and in the that the lining (54) defines the clutch surface for clutch the traction sheave (36).