EP3177555B1 - Elevator system, braking system for an elevator system and method for controlling a braking system of an elevator system - Google Patents

Description

The invention relates to an elevator system, a brake system for an elevator system and a method for controlling a brake system of an elevator system with the features of the independent claims.

Known elevator systems generally comprise a safety catch system which is designed to decelerate and immobilize a free-falling elevator car, and a drive brake, which is arranged in an elevator drive and in operation brakes the elevator system, for example when stopped. EP2107029 discloses a corresponding brake system with a drive brake and a safety gear. The braking system has a brake control device which, upon detection of an abnormal condition, initializes a corresponding braking action.

The drive brake system must be able to safely stop and hold an elevator car in the event of faults. For safety reasons, all parts of the drive brake system are duplicated. As a result, essential parts of the drive brake are present in duplicate, so that if one of the drive brakes fails, safe braking of the elevator car continues to be ensured.

The safety gear or the safety gear system must generally be able to brake and hold the elevator car to a standstill in case of failure of suspension elements or the support system.

Often, additional brakes are arranged on the elevator car (cabin brake system), which also brake the elevator car slightly and thus can dampen vibrations of the elevator car.

Occasionally, cabin brake systems are also used which completely replace the drive brakes and which can safely stop and hold the elevator car. Even with this solution then essential parts of the cabin brake system are duplicated. In this case, the redundancy of the brake system on the one hand leads to an increase in weight of the elevator car, so that possibly stronger drives and more suspension means are necessary. In other cases, a total of often oversized braking performance is present. This in turn results in higher acquisition and maintenance costs.

It is therefore an object of the present invention to provide an elevator system, a brake system for an elevator system and a method for controlling a brake system of an elevator system of the type mentioned, which are overall easy and inexpensive to manufacture and maintain, both for elevator systems with counterweight and for Drum lifts are suitable and can meet the appropriate safety regulations.

This object is achieved essentially by an elevator system with a brake control device. This brake control device can jointly control the cabin brake unit and the drive brake unit in a brake application, so that both brake units are actuated together and these two brake units together result in a redundant brake system.

The proposed elevator system thus comprises an elevator car, at least one elevator drive and suspension means, preferably arranged in an elevator shaft, wherein the elevator car is arranged movably in the elevator shaft by means of the elevator drive via the suspension means. The elevator system further comprises a cabin brake unit, which is assigned to the elevator car, and a drive brake unit, which is assigned to the elevator drive. The cabin brake unit and the drive brake unit are coordinated by the brake control device or jointly controlled. This means that in any case, even in normal operation for the purpose of holding or stopping the elevator car in a stop, the cabin brake unit and the drive brake unit are actuated together or together.

In this case, the safety-relevant redundancy can be achieved by the arrangement of the cabin brake unit and the drive brake unit as well as the coordinated or common activation of the two brakes. If one of the brakes fails, the other of the two brakes still ensures braking.

The common control can also include a time offset of the brake application. In any case, however, a control is carried out such that in case of failure or failure of one of the brake units, the other brake unit provides the braking power in full to keep the elevator car safely or to brake. For this purpose, no further control intervention is required, since it is already ensured by the common control that the redundant component or the other of the two brake units generates its braking effect. This ensures full redundant dual braking safety. This is achieved by always controlling the cabin brake unit and the drive brake unit simultaneously or together. At the same time it also implies that, for example, a small time response delay can be present between the two brake units, so that a resulting impact on the cabin is reduced.

It should be noted that both the drive brake unit as well as the cabin brake unit may each comprise a single brake assembly or a plurality of brake assemblies, which, however, are not redundant and safety terms are understood as a single brake unit. In the case of the cabin brake unit, the plurality of brake assemblies serve essentially to initiate the braking forces in guide rails arranged on both sides of the elevator car or to assemble a plurality of standardized smaller brakes into a cabin brake unit. In the drive brake unit, the plurality of brake assemblies primarily serve to assemble a plurality of standardized smaller brakes into a drive brake unit.

Furthermore, as usual, the communication between the cabin brake unit, the drive brake unit and the brake control unit can take place via (hanging) cables via a bus system or naturally also via signal lines or it can be wireless, for example via radio or infrared signals. Preferably, the communication is executed on the rules of a "fail-safe" communication. This means that if the connection is faulty, the brake units will inevitably brake. This makes the elevator system very safe.

The brake control device can also be arranged as desired, for example on the elevator car or in the vicinity of the drive or on a wall of the elevator shaft. The brake control device can also be integrated or attached in an elevator control device.

Both the cab and the drive brake unit are preferably formed fail-safe. This means that both brake units are actively ventilated. In the event of a fault or a power failure, the brake units thus close automatically. A released brake unit is a brake unit in its open position, that is, it does not brake in this position.

It should be noted at this point that with taxes in the sense of the present invention, both an open loop control and a closed loop control are understood.

Preferably, the cabin brake unit is attached to the elevator car and cooperates with a guide rail of the elevator shaft.
The drive brake unit is preferably arranged directly on the drive of the elevator. There, it preferably acts directly on a traction sheave or a drive shaft of the traction sheave. This is advantageous because a power transmission from the drive brake to the suspension element can be effected as directly as possible and a failure in the power flow from the drive brake to the suspension element is minimized. In this case, the drive brake unit preferably contains a plurality of individual brakes, which are distributed over the circumference of a brake disk, for example.

An arrangement of the cabin brake unit to the elevator car is also advantageous because in addition to the safe braking function, for example, a drifting of the elevator car can be prevented or because of vibrations of the cabin, which eg when entering and exiting passengers or when loading or unloading goods arise, can be largely avoided. The cabin brake unit of the elevator car thus takes over in addition to the actual free fall protection or the function as safety gear the function of holding the car in a floor or the delay of the elevator car in an emergency stop. The braking power in the case of an emergency stop with intact support means can thus be provided redundantly, by the joint action of the drive brake unit and the cabin brake unit.

More preferably, the cabin brake unit comprises two brakes, which are each arranged laterally opposite to the elevator car and which each interact with a guide rail of the elevator shaft.

This ensures that the two brakes, which are arranged laterally on the elevator car stabilize the elevator car and prevent unwanted displacements of the position of the elevator car during braking or during a Halt occur, which in the worst case to a fault of the elevator system (eg Clamping the brake or slipping of guide shoes of the elevator car from the guides) can lead.

In a preferred embodiment, the cabin brake unit can be controlled at least in two stages.

In this preferred embodiment, it is ensured that the cabin brake unit fulfills a dual function. In the first stage, a first braking force is generated, which is smaller than that second braking force, which is generated in a second stage. If the cabin has to be stopped with the support means intact, the cabin brake unit can be actuated in the first stage, thus slowing down the elevator car. Only in a second phase is the second braking force then generated, e.g. to safely decelerate the elevator car in the event of a rope break or free fall. In a rope tear correspondingly larger braking forces are required, since a load-bearing balance by the counterweight is eliminated. Even with a longer stop in a floor, for example, the second braking force can be activated to save energy requirements for keeping open the cabin brake unit.

Preferably, the elevator system is designed as a drum lift system. As a drum lift system in the context of the present invention, an elevator system understood, in which the suspension means is wound on a drum, as in the book "The elevator" of Simmen / Drepper; Prestel Munich; 1984 described. Alternatively or additionally, the elevator system is designed as a lift without counterweight. This can be implemented on the one hand by the drum lift or it can be a suspension means with high traction capability can be used, so that essentially a weight of a counter strand of the suspension means at best together with small guide weights is sufficient to drive the elevator car. A suspension element with high traction capability can be for example a toothed belt or it can be a suspension element which is pressed against a traction sheave by means of a pressing contour or roller or which is tensioned by means of a pretensioning device.

However, the elevator system can also be designed as a conventional traction elevator with a counterweight. As a rule, the counterweight compensates for a weight of the empty elevator car plus a proportion of the permissible load. The permissible payload is to be understood as a nominal or nominal load, that is to say the elevator installation is designed to move this load.
This weighting, that is the proportion of allowable payload compensated by the counterweight, is called balancing. For example, if a balancing factor of 50% is used, this means that the counterweight corresponds to the weight of the empty elevator car plus 50% of the permissible load of the elevator car. The balance factor or the balance is usually in the range between 0 and 50%. This balancing is usually done or changed only once during the initial installation or as part of a conversion of the elevator system.

According to the proposed solution, it can now be seen that in a elevator system according to the invention, the drive brake unit is always single-acting, ie. in terms of safety-related redundancy as a single brake, can be performed. The redundant braking portion is provided by the cab brake unit.

Thus, such a brake system preferably includes a cabin brake unit which is assigned or can be assigned to an elevator car, and a drive brake unit which is assigned or can be assigned to an elevator drive. It can be seen that the proposed braking system is suitable both for new elevator systems and for retrofitting older elevator systems. The aforementioned embodiments of the elevator system are of course also applicable to the brake system itself and vice versa.

The brake system includes the cab brake unit, the drive brake unit, the brake control device and corresponding communication interfaces. The cabin brake unit is, as already explained above, preferably two or more stages controllable or adjustable. Thus, the cabin brake device can be operated as a rule with a smaller braking force and only in a free fall, the entire braking force is applied.

The cabin brake unit and the drive brake unit are preferably structurally designed differently. This means that the cabin brake unit and the drive brake unit each comprise brakes of different types and construction. Thus, the safety of the brake system is increased in the design or technical failure of one of the brake units, since the probability of failure of the remaining, still intact braking unit is lower when the brake unit is structurally different from the failed brake unit. In general, the drive brake unit is designed as a disk brake and the cabin brake unit, for example, as a clamp brake. Preferably, both brakes are electromechanically operated, for example by means of electromagnets.

According to the solution, a method is also provided for controlling a brake system of an elevator system. The elevator system is preferably an elevator system as explained above. The advantages mentioned in the elevator system are also applicable to the inventive method.

The brake system of the elevator system comprises a cabin brake unit associated with an elevator car and a drive brake unit associated with an elevator drive.

The cabin brake unit is preferably controlled in two stages. In a first step, a first braking force is equal to the braking force generated by the drive brake unit issued. In a second step, the cabin brake unit generates a full second braking force.

In a cost effective design, when an emergency stop is triggered, the cab brake unit and the drive brake unit are always controlled to deliver the full braking force. This allows a simple brake control, since with an emergency signal, e.g. Interruption of a safety circuit, always the full braking power is provided. Should a brake not work as expected, the other of the two brakes will still be able to safely stop the elevator car.

With an emergency stop, it can generally be assumed that the suspension elements are intact. As a result, both the cabin brake unit and the drive brake unit are controlled to output the full braking force. In another embodiment, the cabin brake unit can also be activated only in a first braking stage. It gives only a portion of the possible braking force. For example, the elevator car is not stopped abruptly, which is advantageous for passengers and / or goods therein.
In a cabin brake unit, which is divided into two brakes arranged on both sides of the cabin, this can further be advantageous, since in the event of a possible malfunction of one of these two brakes, an asymmetrical braking force is smaller.

Furthermore, known methods for checking the function of the brake system can be used. Thus, for example, the drive brake unit or the cabin brake unit can be briefly or prematurely opened in the stop and a control device can check to what extent the remaining brake unit is able to hold the elevator car at a standstill. In another example, the brake units may be controlled such that when a brake command first one of two braking units used and then, for example, after a short period of time, the other of the two brake units also comes to braking. During the short period of time, the control device can check to what extent the one brake unit can provide sufficient braking power.

Figur 1

eine schematische Seitenansicht eines Aufzugsschachtes einer ersten Ausführungsform der Erfindung,

Figur 2

eine schematische Schnittansicht durch den Aufzugsschacht der Fig. 1,

Figur 3

eine schematische Seitenansicht eines Aufzugsschachtes einer zweiten Ausführungsform der Erfindung, und

Figur 4

eine schematische Seitenansicht eines Aufzugsschachtes einer weiteren Ausführungsform der Erfindung.

The invention will be explained below with reference to the drawings in conjunction with the figures better. Show it:

FIG. 1

a schematic side view of an elevator shaft of a first embodiment of the invention,

FIG. 2

a schematic sectional view through the elevator shaft of Fig. 1 .

FIG. 3

a schematic side view of an elevator shaft of a second embodiment of the invention, and

FIG. 4

a schematic side view of an elevator shaft of a further embodiment of the invention.

In the FIG. 1 schematically an elevator shaft 3 of an elevator system 1 is shown. The elevator system 1 comprises an elevator car 2, which is located on a floor E ₁ . Further floors of the elevator shaft 3 are shown with E ₂ to E _n . The elevator system 1 of FIG. 1 is designed as a traction elevator system 11 with a counterweight 12, wherein the support means 5 are designed as a carrying strap and are guided under the elevator car 2 and a traction sheave 17.

Guide rails 9 for the elevator car 2 and the counterweight 12, which serve to guide and stabilize the elevator car 2 or the counterweight 12, are also provided in the elevator shaft 3. The elevator car 2 is equipped with a car brake unit 6, which is located below the elevator car 2.

The FIG. 2 shows the elevator system 1 schematically from above. Clearly visible are the guide rails 9, which in pairs lead the elevator car 2 and the counterweight 12.

The cabin brake unit 6 of the elevator car 2 consists of two brakes which are arranged laterally below the elevator car 2 in the region of deflection rollers 16 of the suspension element 5. As cabin brake units 6 are primarily electrically controllable Brakes suitable. This can be, for example, magnetically releasable clamp brakes, it can be hydraulic caliper brakes or it can be multi-stage controllable brakes, as for example from the Scriptures EP1930282 is known.

Both brakes of the cabin brake unit 6 cooperate with a respective guide rail 9 for braking the elevator car 2 and also serve as a safety gear. A separate safety gear is not provided.

The elevator system 1 is further equipped in the drive area with a drive brake unit 7, which interacts directly with the elevator drive 4 and the traction sheave 17. The elevator drive 4 may be a drive with gear or a gearless machine. The drive brake unit 7 may be designed as a disc brake, preferably as a spring-applied brake, as a drum brake or other type of construction.

Both the cabin brake unit 6 and the drive brake unit 7 are connected to a common brake control device 8 via a connecting line 18 shown schematically with a dash-dot line and respective communication interfaces 14 and 15, respectively.

In this embodiment, the brake control device 8 is arranged in the elevator shaft 3 and integrated in a control device which also takes over the control of the entire elevator installation 1. Of course, the brake control device 8, in particular if it is a braking system, which is provided for retrofitting already existing elevator systems, be designed as a separate unit. However, the brake control device 8 can also be arranged on the elevator car 2, depending on the application.

In the FIG. 3 a second preferred embodiment of an elevator system 1 according to the invention is shown. The same reference numerals designate the same or equivalent components, which already above regarding the Figures 1 and 2 have been explained.

The elevator system 1 is designed as a traction elevator system 11 with a counterweight 12. The counterweight 12 is in this embodiment - viewed from the floor E ₁ to E _n - arranged behind the car 2. The car 2 and the counterweight 12 are in turn carried by a support means 5, which is deflected and driven via a traction sheave arrangement 17 of the elevator drive 4.

The brake control device 8 is arranged on the elevator car 2. The cabin or drive brake unit 6 or 7 is formed with integrated communication interface 14 or 15 and connected via a connecting line 18 to the brake control device 8.

In the FIG. 4 a further alternative embodiment of an elevator system 1 is shown. The same reference numerals, in turn, designate identical or equivalent components, which have already been discussed above with reference to FIG FIGS. 1 to 3 have been explained.

The elevator system 1 is designed as a counterbalance traction elevator 11a. The cabin 2 is in turn carried by a support means 5. This suspension element 5 is deflected and driven via a traction sheave arrangement 17a of the elevator drive 4. The support means 5 is guided on the opposite side - on the side of the former counterweight - with a substantially loose strand 5.1 loose in the elevator shaft 3. At most, a low tension weight is attached, which, however, serves only a tightening of the strand 5.1 and possibly the same. A traction transmission from the traction sheave arrangement 17a to the suspension element 5 is ensured by a pressure roller 19, which presses the suspension element 5 onto the traction sheave arrangement 17a. In addition, a deflection roller 20 is provided, which deflects the suspension element 5 back into the elevator shaft 3.
Alternatively, the traction sheave assembly 17a according to the present embodiment can be replaced by a drum drive. Here, the support means is wound, for example, in a drum. The hanging in the elevator shaft free strand 5.1 is then omitted.

The brake control device 8 is preferably arranged again in the elevator shaft 3 in this exemplary embodiment. In a counterweightless elevator system 11a, there is an effort to keep the elevator car 2 as light as possible, since the latter Curb weight is not compensated. The arrangement of the brake control device 8 in the elevator shaft 3 takes this into account accordingly. In a simple embodiment, the communication interface 14 on the one hand contains the power supply for an electromagnet of the car brake unit 6 to keep it in its open state and it includes a position signal of the car brake unit 6, which indicates whether the cabin brake unit 6 is in its open or closed position. In a more complex embodiment, of course, other parameters such as wear, temperature, other positions, etc. can be communicated. This type of arrangement and execution of the communication interface 14 can also be used in the other embodiments.
The drive unit 4 accordingly includes the drive brake unit 7 with the associated communication interface 15. The communication interface 15 of the drive brake unit 7 is analogous to the previously explained communication interface 14 of the car brake unit 6.

Hereinafter, an elevator system 1 according to the invention is compared with an elevator system according to the prior art. It is always on an elevator system 1 with a mass of the elevator car 2 = K; a mass of the support means 5 (plus any cable masses) = S and a nominal load = F reference.

In the case of a non-counterweight elevator 11a, such as a drum lift system or a previously discussed traction elevator, there are two drive brake units in the prior art which each have to generate a braking force F _AB > (K + F + S) ^* g. Thus, the elevator car can be securely held or braked with the required redundancy. In addition, there is a safety gear which also generates a braking force F _Fv > (K + F + S) ^* g. By means of the safety gear, the elevator car can be kept independent of the drive in case of failure of the support means. Of course, in the interpretation of the braking force Zuschlag factors for the design of the brake system used to ensure safe operation over a long time.
It can therefore be seen that in this case more than three times the braking force is available. This causes, for example, a response of all three Brake system at the same time a very large delay of the elevator car can occur.

According to one aspect of the solution, it is now proposed to form the drive brake unit 7 for generating a single braking force F _AB > (K + F + S) ^* g, while the cabin brake unit 6 at the same time a braking force F _{KB of} the same order> (K + F + S ) ^* G. The totally producible braking force F _AB + F _KB is thus lower than in a prior art elevator system since totally only approximately twice the braking force is available. The overall safety of the elevator installation is maintained since the cabin brake unit 6 is actuated together or together with the drive brake unit 7.
The determination greater than (>) is to be understood as applying a corresponding surcharge factor. Experience has shown that this factor is about 20% - 50% (factor 1.2 - 1.5), which is aimed at accurately known load ratios of the lower aggregate factor.

In a traction elevator system 11 with a counterweight 12 having a mass = KA ^* F + K + S (the factor KA equals the percentage of nominal load balanced or counterbalanced by the counterweight), the two drive brake units each have a braking force F _AB > ((1 -KA) ^* F) ^* g. For a 50% balancing consequently applies _AB F> ((1-0.5) ^{* F) *} g and therefore applies for a 30% _AB balancing F> ((1-0.3) ^{* F) * g.} Further, the safety gear is designed to generate a braking force F _FV > (K + F + S) ^* g. In addition, additional factors are used for the design of the brake system in order to ensure a reliable function over a longer period of time. It thus follows that an excessive braking force is also available in this case.
The abovementioned formulas for the design of the braking force F _AB apply to a balancing KA in the range from 0 to 50%. A balance above this range is not important in practice or is not applied.

According to one aspect of the solution, it is now proposed to form the drive brake unit 7 for generating a single braking force F _AB > ((1-KA) ^* F) ^* g, while the cabin brake unit 6 also has a braking force F _KB > (K + F + S) ^* G can generate. The total generating braking force F _AB + F _KB is thus lower than in an elevator system according to the prior art.

It can thus be saved costs, since the redundancy within the drive brake unit itself is not necessary. Furthermore, this weight savings are possible, which allow the installation of less expensive and energy-efficient drives.

Instead of the elevator system 1 of FIGS. 1 to 4 For example, a brake system 13 according to the invention comprising a cabin brake unit 6 with associated communication interface 14, a drive brake unit 7 with associated communication interface 15, and a brake control unit 8 can be used for retrofitting in existing elevator systems.

Claims (15)

1. An elevator system (1) comprising an elevator car (2), at least one elevator drive (4) and suspension means (5), wherein the elevator car (2) is arranged so as to be movable in an elevator shaft (3) via the suspension means (5) by means of the elevator drive (4), further comprising a car braking unit (6) which is assigned to the elevator car (2) and a drive braking unit (7) which is assigned to the elevator drive (4), and a brake control device (8),
   characterised in that the brake control device (8), with each application of the brakes, jointly controls the car braking unit (6) and the drive braking unit (7), so that the two braking units (6, 7) are jointly actuated and together form a redundantly working braking system.
2. The elevator system (1) according to claim 1, characterised in that the car braking unit (6) is fastened to the elevator car (2) and cooperates with a guide rail (9) of the elevator shaft (3).
3. The elevator system according to claim 2, characterised in that the car braking unit (6) comprises two brakes, which in each case are arranged lying laterally opposite on the elevator car (2) and in each case cooperate with a guide rail (9) of the elevator shaft.
4. The elevator system (1) according to any one of the preceding claims, characterised in that the car braking unit (6) can be controlled at least in two stages.
5. The elevator system (1) according to any one of the preceding claims, characterised in that the elevator system (1) is designed as a traction elevator system (11a) without a counterweight (12) or as a drum elevator system.
6. The elevator system according to claim 5, characterised in that the drive braking unit (7) and the car braking unit (6) are designed to safely decelerate an elevator car (2) loaded with a permissible load independently of one another, and in each case to generate a braking force (F_AB, F_KB) determined by a sum of a weight (K) of the empty elevator car, a weight (F) of the permissible load and a weight (S) of additional masses, such as suspension means, cabling etc.: $$\mathrm{braking\; force}\left({\mathrm{F}}_{\mathrm{AB}},{\mathrm{F}}_{\mathrm{KB}}\right)\left[\mathrm{N}\right]>\left(\mathrm{K}+\mathrm{F}+\mathrm{S}\right)*\mathrm{g}.$$

   

   g: acceleration due to gravity: 9.81 m/s^2
7. The elevator system (1) according to any one of claims 1 to 4, characterised in that the elevator system (1) is designed as a traction elevator system (11) with a counterweight (12).
8. The elevator system according to claim 7, characterised in that the drive braking unit is designed to safely decelerate the elevator car loaded with the permissible load, taking into account a counterbalance (KA) determined by the counterweight, and accordingly to generate a braking force (F_AB) determined by the counterbalance (KA) in relation to the weight (F) of the permissible load, $$\mathrm{braking\; force\; of\; drive\; braking\; unit}\left({\mathrm{F}}_{\mathrm{AB}}\right)\left[\mathrm{N}\right]\left(\left(1-\mathrm{KA}\right)*\mathrm{F}\right)*\mathrm{g},$$

   

   and that the car braking unit (6) is designed to safely decelerate the elevator car loaded with the permissible load independently of the counterweight, and accordingly to generate a braking force (F_KB) determined by a sum of the weight (K) of the empty elevator car, the weight (F) of the permissible load and the weight (S) of additional masses, such as suspension means, cabling, etc.: $$\mathrm{braking\; force}\left({\mathrm{F}}_{\mathrm{KB}}\right)\mathrm{of\; the\; car\; braking\; unit}\left[\mathrm{N}\right]>\left(\mathrm{K}+\mathrm{F}+\mathrm{S}\right)*\mathrm{g}.$$

   

   g: acceleration due to gravity: 9.81 m/s^2
9. The elevator system according to claim 7, characterised in that the drive braking unit is designed to safely decelerate the elevator car loaded with the permissible load, taking into account a counterbalance (KA) determined by the counterweight, and accordingly to generate a braking force (F_AB) determined by the counterbalance (KA) in relation to the weight (F) of the permissible load: $$\mathrm{braking\; force}\left({\mathrm{F}}_{\mathrm{KB}}\right)\mathrm{of\; drive\; braking\; unit}\left({\mathrm{F}}_{\mathrm{AB}}\right)\left[\mathrm{N}\right]>\left(\left(1-\mathrm{KA}\right)*\mathrm{F}\right)*\mathrm{g},$$

   

   and that the car braking unit is designed to safely decelerate the elevator car loaded with the permissible load in a first braking stage taking account of the counterweight, and accordingly to generate a first braking force (F_{KB_1}) determined by the counterbalance (KA) in relation to the weight (F) of the permissible load: $$\mathrm{braking\; force}\left({\mathrm{F}}_{\mathrm{KB}\_1}\right)\left[\mathrm{N}\right]>\left(\left(1-\mathrm{KA}\right)*\mathrm{F}\right)*\mathrm{g},$$

   

   and that the car braking unit (6) is designed to safely decelerate the elevator car loaded with the permissible load independently of the counterweight, and accordingly to generate a second braking force (F_{KB_2}) determined by a sum of the weight (K) of the empty elevator car, the weight (F) of the permissible load and the weight (S) of additional masses, such as suspension means, cabling, etc:. $$\mathrm{braking\; force}\left({\mathrm{F}}_{\mathrm{KB}\_2}\right)\left[\mathrm{N}\right]>\left(\mathrm{K}+\mathrm{F}+\mathrm{S}\right)*\mathrm{g}.$$

   

   g: acceleration due to gravity: 9.81 m/s^2
10. A braking system (13) for an elevator system (1), comprising a car braking unit (6) which is or can be assigned to an elevator car (2), and a drive braking unit (7) which is or can be assigned to an elevator drive (4), and a brake control device (8), characterised in that the brake control device (8) is connected via a communication interface (14, 15) to the car braking unit (6) and the drive braking unit (7), and that the brake control device (8), with each application of the brakes, jointly controls the car braking unit (6) and the drive braking unit (7), so that the two braking units (6, 7) are jointly actuated and together form a redundantly working braking system.
11. The braking system according to claim 10, characterised in that the car braking unit (6) and the drive braking unit (7) are designed structurally differently.
12. A method for controlling a braking system of an elevator system (1) according to any one of claims 1 to 9, with a car braking unit (6) assigned to an elevator car (2) and a drive braking unit (7) assigned to an elevator drive (4),
    characterised in that the car braking unit (6) and the drive braking unit (7) are jointly controlled, with each application of the brakes, by a brake control device (8), so that the two braking units (6, 7) are jointly actuated and together form a redundantly working braking system.
13. The method according to claim 12, characterised in that the car braking unit (6) is controlled in such a way that, in a first step, the first braking force (F_{KB_1}) is delivered equal to the braking force (F_AB) generated by the drive braking unit (7).
14. The method according to claim 13, characterised in that, in a second step, the raised second braking force (F_{KB_2}) is delivered.
15. The method according to any one of claims 12 to 14, characterised in that, when an emergency stop is triggered, the car braking unit (6) and the drive braking unit (7) are controlled so as to deliver the first braking force (F_AB,F_KB-1) and/or that, when a freefall of the elevator car (2) is detected, the car braking unit (6) and the drive braking unit (7) are controlled so as to deliver the second braking force (F_AB, F_{KB_2}).

Images