DE102019201783A1 - Elevator system with car earthing - Google Patents

Abstract

The invention relates to an elevator system with at least one elevator car (28) which can be moved along a guide rail (52) in an elevator shaft. At least one first roller (54) is arranged between the elevator car (28) and guide rails (52), the first roller (54) being designed as a grounding roller. This makes it possible to avoid charging of the car (28) during travel.

Description

The invention relates to an elevator system with a car that can be moved in one direction of travel along the elevator shaft. Elevators are used to transport passengers between different floors of a building. For this purpose, a car is moved between the floors within an elevator shaft. For this purpose, the car is traditionally connected to a counterweight via a support cable, the cable running over a driven drive pulley. Alternative elevator systems, on the other hand, no longer use counterweights and are driven by linear drives that are integrated into the rails and cars. The elevator car is then equipped, for example, with permanent magnets to which magnetic fields are applied by coils arranged along the elevator shaft. In this way, the driving force is transmitted to the car. In addition, traditional cars are connected to the shaft wall of the elevator shaft via a traveling cable. This traveling cable ensures an energy supply for the car, which is used, for example, to operate the interior lighting of the car and the control elements inside the car. In newer elevator systems, however, the elevator car is not only moved up and down, but also between several vertically extending elevator shafts. Such an elevator system is known, for example, from JP H06-48672. Any connection between the car and the shaft wall via a cable (eg a hanging cable for power supply) can therefore only be implemented with great difficulty in such systems. Instead, the car is supplied with energy, for example, via energy storage devices in the car. These energy stores are then occasionally charged while the car is stopped, in which a current collector of the car is briefly brought into contact with a power source. A possible variant is in the DE 10 2016 223 913 described. The waiver of permanent conductive connections (e.g. carrying cable, lower cable, hanging cable, sliding contacts) between the car and the elevator shaft leads to the problem that a static charge builds up in the car while the car is moving. On the one hand, this is due to the friction between the plastic rollers and the guide rails. On the other hand, the magnetic fields of the linear drive also caused a charge separation in the conductive elements of the car. If a conductive connection to the building is established when the car is stopped (for example by the pantograph mentioned above or by passengers entering the car), a discharge with a voltage peak occurs. Sensitive electrical components can be damaged by such a charge or the voltage spike during discharge. In addition, unloading via passengers should of course be avoided in order to rule out any health risks. In principle, the electrical components could be designed in such a way that they tolerate charging or voltage spikes. However, this would require the use of significantly more expensive electrical components in the car electronics. In addition, the second problem, the risk of unloading over passengers, would persist.

The object of the present invention is therefore to provide an elevator system in which charging of the car is largely avoided even without a cable or rope connection between the car and the building.

This object is achieved by an elevator system with at least one elevator car that is movable along a guide rail in an elevator shaft. Furthermore, the elevator system has at least one first roller arranged between the lift car and the guide rail, the first roller being designed as a grounding roller. There is thus a permanent conductive connection between the car and the guide rail via the first roller, so that the car cannot become highly charged. In addition, the permanent contact ensures that no voltage peaks can occur during discharge.

In a preferred development, the first roller has a first running body with a running surface and a first central body, the electrical resistance between the running surface and the first central body being less than 10 ⁵ ohms (ie 100 kOhm), in particular less than 2 × 10 ⁴ ohms (ie 20 kOhm) is. In particular, the resistance is between 5 × 10 ³ ohms and 1.5 × 10 ⁴ ohms (ie between 5 kOhm and 15 kOhm).

Guide rollers for cars typically have a cylindrical, metallic central body. The running body is then arranged around this central body. This usually consists of an insulating plastic. Therefore, there is no conductive connection between the car and the guide rails in conventional guide rollers. In the case of the first roller according to the invention, however, the first running body is specially developed so that the electrical resistance between the outer running surface and the inner central body lies in the above-mentioned range.

In a special embodiment, the first roller has a first running body with a running surface, the first running body having an end face with a coating to increase the conductivity. The application of a coating is a relatively simple variant to generate a suitable conductivity without significantly changing the running properties of the first roller. The first running body can be made of a known material. The running properties of the first running body are thus known. The coating on the front side has no significant influence on the running properties.

In a further special embodiment, the first roller has a first running body with a running surface, the running body comprising a plastic with an additive to increase the conductivity. This has the advantage that the entire first running body itself is now used as an electrical connection for the grounding. This ensures a stable, permanent electrical contact between the car and the guide rail. In the case of the lateral coating described above, only a small cross section, namely the area in which the coating touches the guide rails, contributes to the electrical conduction. Therefore, the electrical contact can be interrupted at this point. In contrast to this, the addition of increasing the conductivity leads to the fact that the first running body itself functions as a grounding conductor. The electrical contact between the first roller and the guide rail is thus ensured through the entire contact area of the first running body with the guide rail. The electrical connection is therefore particularly stable against interruptions.

A thermoplastic polyurethane is used in particular as the plastic for the first running body. This material is known for guide rollers and has good long-term stability and little abrasion.

Conductive additives to increase conductivity include, for example, carbon fibers, carbon nanotubes or at least one salt. The embedding of these substances in plastic has been tried and tested and has only a minor influence on the physical properties of the plastic.

In a special development of the elevator system, the first roller comprises a second running body, the electrical resistance of the first running body being lower than the electrical resistance of the second running body. The first role thus comprises two running bodies, one of the running bodies (the first running body) being suitably modified in order to perform the function of grounding. The other running body (the second running body) remains unchanged and serves as a guide roller. As a result of this division into two parts it can be achieved that the first roller can be used as a normal guide roller and at the same time serves as grounding. In this configuration, in particular the second running body is harder than the first running body, so that the first running body is relieved. The forces between the car and the guide rails are thus transmitted via the second running body, which is designed like an ordinary running body of a guide roller, while the electrical line runs over the first running body. The fact that the forces between the elevator car and the guide rail essentially run via the second running body result in more options for the design of the first running body, in particular when choosing an additive to increase conductivity. Softer materials or materials with a higher abrasion can also be used for the first running body.

In a further developed variant of the elevator system, the first roller is resiliently mounted on a roller carrier of the elevator car. This has the advantage that the first roller is pressed against the guide rails with a preset pressure force. This force can be adjusted so that on the one hand there is a permanent electrical connection, but on the other hand the first roller is not mechanically stressed too much by unnecessarily high forces.

Another embodiment of the elevator system provides that the elevator system comprises at least one guide roller which is arranged between the elevator car and the guide rail in such a way that the first roller is relieved. This has the effect that the forces required for guidance between the car and guide rails are transmitted via the guide roller and not via the first roller. This results in more options for the design of the first running body, in particular for the selection of an additive to increase the conductivity. Softer materials or materials with a higher abrasion can also be used for the first running body.

In an alternative embodiment of the elevator system, the elevator system comprises a discharge element. In addition, the first roller has a first running body, the first running body being designed such that a roller axis of the first roller is at a smaller distance from the guide rail in a static state than in a dynamic state. This has the effect that the discharge element is in contact with the guide rail in the static state and has moved away from the guide rail in the dynamic state. This has the effect that each time the car is stopped, electrical contact is established between the car and the guide rails via the discharge element. At the same time, the electrical contact is interrupted again when the car starts up. As a result, the discharge element does not rub against the guide rail during travel. Particularly advantageous for this change in distance due to the dynamic behavior of the material of the first running body achieved. For example, the first running body has a soft material, in particular a soft plastic (in particular a more soft relief). During a stop, the first running body is then pressed in by the forces between the car and the guide rail. There is a static distance between the roller axis and the guide rail. The more the first running body is pressed in, the smaller this static distance is. When starting up, the dynamic behavior of the soft material of the first running body (flexing of the running body) means that this indentation is reduced. The dynamic distance (distance while driving) between roller axis and guide rails is therefore greater than the static distance. This change in distance ensures that the electrical contact between the discharge element and the guide rail is established when stopping and is interrupted again when starting. Additional activation or regulation is not required, which makes it particularly cost-effective to use.

• 1 eine Aufzuganlage in einer beispielhaften Ausführungsform;
• 2 eine Aufsicht auf ein Fahrkorb mit einem Linearantrieb in einer beispielhaften Ausführungsvariante;
• 3 ein Aufriss eines Ausschnitts eines Linearantriebs;
• 4 eine Ausschnittsvergrößerung eine Aufzuganlage mit einer ersten Rolle als Erdungsrolle in einer Seitenansicht;
• 5 eine Draufsicht einer zweiteiligen ersten Rolle als Erdungsrolle;
• 6 eine Draufsicht einer ersten Rolle mit Beschichtung als Erdungsrolle;
• 7a eine Seitenansicht einer ersten Rolle während eines Haltes;
• 7b einer Seitenansicht einer ersten Rolle während der Fahrt.

The invention is explained in more detail below with reference to the figures; shows therein

• 1 an elevator installation in an exemplary embodiment;
• 2 a plan view of a car with a linear drive in an exemplary embodiment variant;
• 3 an elevation of a section of a linear drive;
• 4th an enlarged detail of an elevator system with a first roller as a grounding roller in a side view;
• 5 a plan view of a two-part first roller as a grounding roller;
• 6 a plan view of a first roller with coating as a grounding roller;
• 7a a side view of a first roller during a stop;
• 7b a side view of a first roller while driving.

1 shows a rope-less elevator system 20th in an exemplary embodiment that is in a structure or building 22nd with different levels or floors 24 can be used. The elevator system 20th includes an elevator shaft 26th and at least one car that is movable in one direction of travel in the elevator shaft 28 . The elevator shaft 26th can, for example, three lanes 30th , 32 , 34 include. Any number of cars can be used 28 along one of the lanes 30th , 32 , 34 can be moved in any direction (up or down). For example, as shown, the cars 28 on the roadways 30th and 34 travel in the upward direction while the cars 28 on the roadway 32 drive in the downward direction. Above the top floor 24 there is an upper transfer device 36 who have favourited the elevator cars 28 allows between the lanes 30th , 32 , 34 switch. Below the lowest floor 24 there is a lower transfer device 38 who have favourited the elevator cars 28 also allows between the lanes 30th , 32 , 34 switch. Of course, it is also possible that the upper and the lower transfer device 36 , 38 alternatively on the top and bottom floors 24 itself is arranged instead of above or below the top or bottom floor 24 . Furthermore, the relocating devices can also be on any floor in between 24 be arranged. It is also possible that the elevator system 20th one or more relocating devices, which in the vertical direction between an upper and a lower relocating device 36 , 38 are arranged.

The further structure is with reference to the 1-3 explained in more detail. The cars 28 are driven by a linear drive 40 . The linear drive 40 has primary parts 42 on (for example four primary parts shown in 2 ), which are arranged in a stationary manner. For example, the primary parts are attached at least indirectly to a shaft wall. Furthermore, the linear drive has movable secondary parts 44 on (for example four abutments 44 in 2 ). The primary parts 42 include coils 48 which are arranged on one or both sides of the roadway. The abutments 44 including permanent magnets 50 that are on one or both sides of the car 28 are attached. The primary parts 42 generate a magnetic field based on a control signal. This way the abutments 44 when a force is applied, all the more a movement of the cars 28 in their lanes 30th , 32 , 34 to realize.

In the 2 and 3 is a first pair of abutments 44 of the linear drive 40 on a first side of the car 28 attached, and a second pair of abutments 44 is on an opposite side of the car 28 appropriate. Between the abutments 44 the primary parts are arranged in a pair. Any number of secondary parts can of course 44 at the car 28 be attached and with any number of primary parts 42 cooperate, which are arranged stationary.

4th shows an enlarged detail of an elevator system 20th . A side view of the car is shown 28 and guide rail 52 . Between the car 28 and the guide rail 52 is a first role 54 arranged. The first role 54 has a first central body 56 and a first running body 58 on. The first central body 56 to typically made of metal and in particular comprises a bearing that ensures the rotatability of the first roller about a central axis. The running body 58 encloses the central body 56 and has a substantially cylindrical shape with two end faces and a running surface. While the car is moving 28 rolls the first roll 54 on the guide rail 52 from. It touches the tread 60 the guide rail 52 . The running body 58 has a plastic, in particular a thermoplastic polyurethane.

The first role 54 is designed as a grounding roller. This means that any tension that has built up on the car can be discharged via the first roller. With ordinary guide rollers only possible to a very limited extent, since the running body 58 ordinary guide rollers made of an insulating material. In contrast, the first role shown has 54 a running body 58 with an increased conductivity. The electrical resistance between the tread 60 and the central body 56 is in the range of 10 ⁴ ohms. This increased conductivity is achieved by the fact that the material of the running body 58 an addition to increase the conductivity is included. For example, the running body comprises 58 a plastic, in particular a thermoplastic polyurethane, to which a corresponding additive is added. The additive can include, for example, fibers, in particular carbon fibers, carbon nanotubes or at least one salt.

However, the addition of these substances also has some disadvantages. For example, the abrasion and thus the durability of the first roller can increase 54 reduce. When using fibers, in particular carbon fibers, or carbon nanotubes, the further problem arises that the fibers or carbon nanotubes can break when the material is loaded. Such a material load can occur in the case of guide rollers, since larger forces are sometimes transmitted from the car to the guide rail via the guide roller. In addition, these forces do not act uniformly, but rather always at a different point on the running body of the guide roller due to the rolling of the guide roller on the guide rail. When the car is moved, the running body of the guide roller is therefore flexed. This constant flexing can also lead to breakage of the fibers or carbon nanotubes. Breaking the fibers or carbon nanotubes has the disadvantage that the conductivity is reduced and the desired effect no longer comes into play over time.

These disadvantages described are avoided by the running body 58 the first role 54 is relieved. In the embodiment according to 4th this is achieved by having the first role 54 on a roller carrier 62 of the car 28 is resiliently mounted. The role axis is for this purpose 64 the first role 54 via the connecting element 66 and the pen 68 with the roller carrier 62 connected. The feather 68 is in 4th shown schematically as a mechanical spring. Alternatively, hydraulic or pneumatic suspension can also be used. At the same time, the elevator system includes 20th at least a leadership role 70 that between car 28 and guide rail 52 is arranged. The leadership role 70 is adjacent to the first roll 54 at the car 28 arranged. The transfer of forces between the car 28 and the guide rail 52 takes place in this arrangement via the guide roller 70 instead of. The first role 54 is just using the spring 68 to the guide rail 52 pressed so that the electrical contact between the first roller 54 and guide rail 52 remains stable.

Another variant for executing the first role as a grounding role is in 5 shown. 5 shows a plan view of the area between the car 28 and guide rail 52 . Between the car 28 and guide rail 52 is a first role 54 arranged. The first role 54 has a first central body 56 and a first running body 58 on. Also includes the first role 54 a second running body 72 . Due to the view from above to the central body 56 through the two running bodies 58 and 72 covered. The second running body 72 is harder than the first barrel in this variant 58 . The power transmission between the car 28 and guide rail 52 therefore takes place essentially via the second running body 72 instead of. The first running body 58 is, however, relieved. This becomes the material of the first running body 58 spared. Instead, the first running body is used 58 to the fact that there is a tension on the car 28 has built up over the first barrel body 58 can discharge. To this end, the first running body 58 an electrical resistance which is lower than the electrical resistance of the second running body 72 . In particular, the first running body 72 performed as in the embodiment according to 1 .

6 shows another variant of the execution of the first role 54 as a grounding role. The representation corresponds to the representation of 5 Identical elements are provided with the same reference numerals. With the variant after 6 the discharge of the voltage is achieved in that the first running body 58 an end face 74 with a coating 76 to increase the conductivity. The tension in this case is via the central body 58 and the coating 76 in the Guide rail 52 derived. Of course, this variant can also be used with the embodiments of 4th and or 5 can be combined so that each effect contributes part of the desired higher conductivity.

The 7a and 7b show another alternative variant for the execution of the first role 54 as a grounding role. The representation corresponds to the representation of 4th , the same elements being provided with the same reference numerals. With the variant after the 7a and 7b the discharge of the voltage is achieved in that the elevator system has a discharge element 78 comprises and the first running body 58 a soft material, in particular a soft plastic, particularly preferably a soft elastomer. 7a shows the arrangement when the car is at a standstill 28 . Due to the soft material of the first running body 58 becomes the first running body 58 depressed. The roller axis 64 then has a static distance d _S from the guide rail 52 . The discharge element 78 is in contact with the guide rail 52 so that an electrical connection between the car 28 and the guide rails 52 for grounding. 7B shows the same arrangement with a moving car 28 . The dynamic behavior of the soft material of the first running body 58 (Flexing of the running body) leads to the dynamic distance d _D between running axis 64 and guide rails 52 is greater than the static distance d _S. This increase in distance causes the discharge element 78 from the guide rail 52 has moved away. The discharge element 78 so does not rub against the guide rail while driving 52 so that there is no excessive wear. In the illustration shown is the discharge element 78 over the holder of the first roll 54 at the car 28 attached. Alternatively, it is also possible for the discharge element 78 directly on the car 28 to fix.

List of reference symbols

20th

Elevator system

22nd

building

24

Floors

26th

Elevator shaft

28

Cars

30, 32, 34

roadway

36

upper transfer device

38

lower transfer device

40

linear actuator

42

Primary part of the linear drive

44

Secondary part of the linear drive

48

Do the washing up

50

Permanent magnets

52

Guide rail

54

first role

56

first central body

58

first running body

60

Tread

62

Roller carrier

64

Roller axis

66

Connecting element

68

feather

70

Leadership role

72

second running body

74

Face

76

Coating

78

Discharge element

d _S

static distance

d _D

dynamic distance

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016223913 [0001]

Claims (13)

Elevator installation (20) comprising - at least one car (28) movable in an elevator shaft (26) along a guide rail (52) and - at least one first roller (54) arranged between the elevator car (28) and guide rail (52), characterized in that the first roller (54) is designed as a grounding roller. Elevator system after Claim 1 , characterized in that the first roller (54) has a first running body (58) with a running surface (60) and a first central body (56), the electrical resistance between the running surface (60) and the first central body (56) being smaller 10 ⁵ ohms, in particular less than 2 × 10 ⁴ ohms. Elevator system according to one of the Claims 1 - 2 characterized in that the first roller (54) has a first running body (58) with a running surface (60), the first running body (58) having an end face (74) with a coating (76) to increase the conductivity. Elevator system according to one of the Claims 1 - 3 characterized in that the first roller (54) has a first running body (58) with a running surface (60), the running body (58) comprising a plastic with an additive to increase the conductivity. Elevator system after Claim 4 , characterized in that the plastic is a thermoplastic polyurethane. Elevator system according to one of the Claims 4 - 5 , characterized in that the additive comprises carbon fibers, carbon nanotubes or at least one salt. Elevator system according to one of the Claims 2 - 6 , characterized in that the first roller (54) comprises a second running body (72), the electrical resistance of the first running body (54) being lower than the electrical resistance of the second running body (72). Elevator system after Claim 7 , characterized in that the second running body (72) is harder than the first running body, so that the first running body (54) is relieved. Elevator system according to one of the Claims 1 - 8th , characterized in that the first roller (54) is resiliently mounted on a roller carrier (62) of the elevator car (28). Elevator system according to one of the Claims 1 - 9 , characterized in that the elevator system (20) comprises at least one guide roller (70) which is arranged between the elevator car (28) and the guide rail (52) in such a way that the first roller (54) is relieved. Elevator system after Claim 1 , characterized in that the elevator system (20) comprises a discharge element (78) and the first roller (54) has a first running body (58), the first running body (58) being designed such that a roller axis (64) of the first Roller (54) has a smaller distance from the guide rail (52) in a static state than in a dynamic state, so that the discharge element (78) is in contact with the guide rail (52) in the static state and from the guide rail in the dynamic state (52) has moved away. Elevator system after Claim 11 , characterized in that the first running body (58) comprises a soft material, in particular a soft plastic, preferably a soft elastomer. Elevator system according to one of the Claims 1 - 12th comprising a linear drive (40) for driving the elevator car (28) along a direction of travel.

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