HK1183470B - Elevator system with rope sway detection - Google Patents

Description

Elevator system with rope sway detection

Technical Field

The present invention relates to the field of elevator systems, and more particularly to the field of elevator systems with rope sway detection.

Background

Elevator systems are useful for transporting passengers between floors in, for example, a building. There are various known types of elevator systems. Different design considerations dictate the type of components included in the elevator system. For example, elevator systems in high-rise and multi-story buildings have different requirements than elevator systems for buildings that include only a few floors.

One problem that exists in many high-rise and multi-story buildings is the tendency to experience rope sway under various conditions. Rope sway may occur, for example, during an earthquake or a very high wind condition, as the building will move in response to the earthquake or high wind. As the building moves, the long ropes associated with the elevator car and counterweight will tend to sway from side to side. Rope sway sometimes occurs when there is a high vertical air flow velocity in the elevator hoistway. Such air flow is associated with the well known "building chimney or chimney effect".

Excessive rope sway conditions are undesirable for two primary reasons; they can cause damage to the ropes or other equipment in the hoistway and their movement can produce objectionable noise and vibration levels in the elevator car.

Various swing reduction techniques have been proposed. Most include some type of damper positioned to interrupt side-to-side movement of the rope at one or more points in the hoistway. Other proposals include controlling movement of the elevator car during a rope sway condition. E.g. us patent No. 4,460,065 discloses detecting sway movement of the compensating ropes and thereby limiting movement of the elevator car.

Disclosure of Invention

An exemplary elevator system includes a first mass movable within a hoistway. The second mass is movable within the hoistway. A plurality of elongated members couple the first mass to the second mass. At least one damper is positioned to selectively contact at least one of the elongated members if sway occurs. A sensor is associated with the damper. The sensor provides an indication of contact between at least one of the elongate members and the damper. The controller adjusts at least one aspect of elevator system operation in response to the indication provided by the sensor.

An exemplary method of responding to sway in an elevator system including at least one damper for selectively contacting at least one elongate member if sway occurs includes sensing contact between the damper and the elongate member. At least one aspect of elevator system operation is adjusted in response to the sensed contact.

The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

Drawings

Fig. 1 schematically illustrates select portions of an example elevator system.

FIG. 2 is a perspective illustration of an example damper.

FIG. 3 schematically illustrates another example damper.

Detailed Description

Fig. 1 schematically illustrates select portions of an example elevator system 20. The illustrated example provides background for discussion purposes. The configuration of the elevator system components may differ from this example in various respects. For example, the roping arrangement, the location of the rope sway damper and the type of damper may be different. The present invention is not necessarily limited to the illustrated example elevator system configuration or specific components.

Both the elevator car 22 and the counterweight 24 are movable within a hoistway 26. A plurality of elongated members 30 (i.e., traction ropes) couple the elevator car 22 to the counterweight 24. In one example, the traction ropes 30 comprise round steel ropes. Multiple roping arrangements can be useful in elevator systems that include features designed according to embodiments of this invention. For example, the traction ropes may comprise flat belts instead of round ropes.

In the example of fig. 1, the traction ropes 30 are used to support the weight of the elevator car 22 and counterweight 24 and urge them in a desired direction within the hoistway 26. The elevator machine 32 includes, for example, a traction sheave 34 that rotates the traction ropes 30 and causes the traction ropes 30 to move to cause desired elevator car 22 movement. An exemplary arrangement includes a deflector or idler 36 for guiding movement of the load cable 30. The illustrated example includes a single winding configuration. Other roping arrangements are possible including rewind traction in which the traction ropes 30 have a return loop around the traction sheave 32 that increases the effective wrap angle (wrapangle) on both the traction sheave 32 and the idler sheave 36.

During movement of the elevator car 22 under certain conditions, it is possible that the traction ropes 30 will move laterally (i.e., sway) in an undesirable manner. The traction sheave 34 is intended to cause the traction rope 30 to move longitudinally (i.e., along the length of the rope). Lateral movement (i.e., transverse to the direction of longitudinal movement) is undesirable, for example, because it can produce vibrations that degrade the ride quality of passengers within the elevator car 22, can produce objectionable noise and can result in elevator rope wear and reduced life. Additionally, in some cases, the rope may become entangled with other equipment or structural elements in the hoistway.

The portion 38 of the traction ropes 30 between the elevator car 22 and the traction sheave 34 will have a tendency to move laterally under certain elevator operating conditions (e.g., during elevator operation), certain building conditions, certain hoistway conditions, or a combination of two or more of these. For example, during windy days (when the building sways) when there is a rapid movement of the elevator car 22 from a lower floor to one of the highest floors in the building, there may be a tendency for the traction ropes 30 to sway. This portion 38 can move laterally in a manner that causes the elevator car 22 to vibrate, especially when the length of the sway rope shortens during normal elevator motion. Such lateral movement or rocking is shown virtually in the "left and right" direction (according to the figure) schematically at 38' in fig. 1. Lateral movement (according to the figure) into and out of the page is also possible.

The example elevator system 20 includes at least one damper 50 for mitigating the amount of rope sway to minimize the amount of vibration of the elevator car 22. The damper 50 is located in a fixed position relative to the hoistway 26. In this example, the damper 50 is supported on a structural element 53 of the hoistway 26, such as a floor associated with a machine room for housing the machine 32. If there is sufficient rope sway, the dampener 50 reduces the amount of lateral movement or sway of the portion 38 of the traction rope 30 by contacting at least some of the traction ropes 30 at a fixed location of the dampener. For example, the damper absorbs vibration energy in the traction ropes 30 so that the energy is not converted into vibration of the elevator car 22.

A sensor 52 is associated with the damper 50. The sensor 52 detects contact between the damper 50 and at least one of the ropes 30. The sensor provides an indication of such contact to the elevator controller 54. Based on the indication, the elevator controller 54 adjusts at least one aspect of elevator system operation in response to the sway condition resulting from the sensor 52 causing the resulting indication.

Another portion 56 of the traction ropes 30 is present between the counterweight 24 and the idler sheave 36. It is possible that there is sway or lateral movement in the portion 56 of the load cable 30. The example of fig. 1 includes a damper 60 in a fixed position relative to the hoistway 26 for reducing the amount of sway in at least the portion 56. The damper 60 has an associated sensor 62 that provides an indication to the elevator controller 54 of contact between the damper 60 and the at least one traction rope 30.

The illustrated elevator system 20 includes a plurality of compensation ropes 70 (e.g., elongated members such as round ropes). Portions 72 of these compensation ropes 70 are present between the counterweight 24 and the sheaves 78 near the opposite end of the hoistway as compared to the end of the hoistway where the machine 32 is disposed. Because the portion 72 of the compensation rope 70 may move or sway laterally under certain elevator operating conditions, the damper 80 is provided in a fixed position relative to the hoistway 26. The damper 80 is supported in this example on a hoistway structural member 84, such as a portion of a building, proximate to a pit, such as where the wheels 78 are located. The damper 80 has an associated sensor 82 that communicates with the elevator controller 54. The sensor 82 provides an indication of the sway of the portion 72 when the compensation rope 70 contacts the damper 80.

Another portion 86 of the compensation ropes 70 is between the elevator car 22 and the sheave 92. In this example, the damper 94 is supported on the structural member 84 of the hoistway 26. The damper 94 has an associated sensor 96 that, like the other example sensors, communicates with the elevator controller 54.

Some example elevator systems will include all of dampers 50, 60, 80, and 94. Other example elevator systems will include only selected ones of these dampers or other dampers in other locations. Still other examples will include different combinations of selected ones of the example dampers. Given this description, those skilled in the art will recognize that damper sites and configurations meet their particular needs.

FIG. 2 illustrates an example damper 50. For example, the configuration of dampers 60, 80 and 94 in fig. 1 may be the same as that shown in fig. 2. The illustrated damper 50 includes impact members 102 and 104 positioned to remain clear of the traction ropes 30 during acceptable elevator operating conditions (e.g., desired rope longitudinal movement without lateral movement). The fixed position of the elevator car 50 outside of the travel path of the elevator car 22 and the clearance between the ropes and the impact member allow the damper 50 to remain in a fixed position (with the impact members 102 and 104 always ready to mitigate undesired sway of the traction ropes 30). That is, the damper 50 is passive in nature in that it does not have to be actively deployed or moved to a position where it will perform a sway mitigation function. In another example, the damper is actively deployed or moved to a sway mitigation position under selected conditions. The damper 50 is adapted to damp the rope sway level at any time that rope sway occurs.

The impact members 104 and 102 in this example comprise bumpers having rounded surfaces configured to minimize wear on the traction ropes 30 due to contact between the traction ropes 30 and the impact members 102 and 104 (resulting from lateral movement of the traction ropes 30). The spacing between the impact members 102 and 104 and the load cable 30 minimizes any contact therebetween except in situations where an undesirable amount of lateral movement of the cable 30 occurs.

In the illustrated example, the damper frame 106 supports the impact members 102 and 104 in a desired position to maintain spacing from the traction ropes 30 in many elevator system conditions. The illustrated example includes a mounting pad 108 between the frame 106 and the hoistway structural member 53. These mounting pads 108 reduce any transmission of vibrations into the structure 53 due to collisions between the traction ropes 30 and the collision members 102 and 104, which minimizes the possibility of noise being transmitted into the hoistway. In the illustrated example, the spacing between the impact members 102 and 104 is less than the spacing provided in the gap 110 in the floor or structural member 53 through which the load cable 30 passes. This closer spacing between the impact members 102 and 104 as compared to the size of the gap 110 ensures that the traction ropes 30 will contact the impact members 102 and 104 before having any contact with the structural member 53.

In one example, the impact members 102 and 104 include rollers that roll about an axis in response to contact with the moving traction ropes 30 in a sway condition.

In this example, the sensor 52 includes a sensor element 52a that detects when the associated impact member 102 or 104 is rotating due to contact with the moving traction rope 30. Such contact will occur in a sway condition when there is lateral or side-to-side movement of at least one of the traction ropes 30. One example sensor element 52a includes a potentiometer that provides an analog signal indicative of the amount of rotation of the associated impact member. Another example sensor element 52a includes a rotary encoder. The sensor element 52a may also provide information regarding the amount of time during which the impact members 102 and 104 are rotating due to contact with the traction ropes 30.

The indication of the amount of rotation, the amount of time during which the rotation occurs, or both, may provide information to the elevator controller 54 regarding the severity of the sway condition. For example, a relatively slight sway will result in a smaller amount of rotation of the impact member than a larger amount of sway or sway occurring over a longer period of time. Similarly, the length of time when the impact members 102 and 104 rotate indicates the amount of sway in the traction ropes 30 (as continuous contact between at least one of the traction ropes 30 and the impact members indicates a sustained sway condition). Thus, the illustrated example provides an indication of the amount of sway to the elevator controller 54 so that the elevator controller 54 can respond by changing at least one operating parameter of the elevator system 20 to address the sway condition.

One example includes using the elevator controller 54 to slow movement of the elevator car 22, limit the length of elevator up or down landing runs, stop the elevator car 22, move the elevator car 22 to a designated point within the hoistway 26 that is considered a vantage point (during a sway condition), cause the elevator car 22 to go to the nearest landing and cause the elevator car doors to open to allow passengers to exit the elevator car, or a combination of one or more of these, depending on the indicated level from the sensor 52.

In one example, the impact members 102 and 104 include an elastic material that absorbs some of the energy associated with the lateral movement of the load cable 30. Absorbing such energy reduces the amount of sway and elevator car vibration.

This example includes an additional sensor element 52b that provides an indication of the force associated with contact between the impact members 102 and 104 and at least one of the load cables 30. For example, a strain gauge or load cell is associated with the impact member for providing an indication of the force (resulting from contact with the load cable) exerted on the impact member. The indication of this force provides additional signals to the controller 54 regarding the severity of the sway condition. For example, a greater amount of sway will result in a greater applied force.

The elevator controller 54 is programmed in one example to select how to adjust at least one parameter in the elevator system 20 based on the severity of the sway condition indicated by the signal from at least one of the sensor elements 52a or 52 b. One example includes pre-programming the elevator controller 54 to select an appropriate response action based on a predetermined sensor output. Given this description, those skilled in the art will recognize how to select appropriate elevator control operations to meet their particular situation needs in response to different sway conditions.

In one example, the controller is effective to eliminate adjustments triggered by detected rope sway or to reset system operation to normal operating conditions based on continuously monitoring output from one or more of the sensors 52, 62, 82, and 96. Once the sensor output information indicates that the sway condition has terminated, the elevator system 20 can resume normal operation.

Fig. 3 illustrates another example damper configuration, where the impact members 102 and 104 are rollers that rotate in response to contact with the traction ropes 30 as the ropes are moving longitudinally and laterally. In this example, the frame 106 is configured to allow lateral movement of the impact members 102 and 104 in response to contact with the load cable 30. The biasing member 112 urges the impact members 102 and 104 into a rest position in which they maintain a spacing from the load cable 30 under most conditions. In one example, the biasing member 112 includes a mechanical spring, a gas spring, or a hydraulic damping device. The impact between the load cable 30 and one of the impact members 102, 104 tends to urge the impact member away from the other to oppose the bias of the biasing member 112. This arrangement provides additional energy absorption characteristics for further reducing the amount of vibrational energy in the cord 30 (as energy is expended to overcome the bias of the biasing member 112).

As can be appreciated from the figures, when the traction rope 30 moves longitudinally (as shown by arrow 114) and laterally (as shown by arrow 116), any contact between the traction rope 30 and one of the impact members 102 or 104 will cause rotation (as schematically shown by arrow 118) and will tend to urge the impact members away from each other to oppose the bias of the biasing member 112 (e.g., in the direction of arrow 116).

In this example, the sensor element 52a provides an indication of the amount of lateral or side-to-side movement of the impact members 102 and 104. The linear transducer is used in one example to detect the amount of movement of the impact members 102 and 104 away from each other. Another example includes a proximity switch. The example of fig. 3 also includes a sensor element 52b, such as a rotary potentiometer or rotary encoder, for providing an indication of the amount of rotation of the impact members 102 and 104 in response to contact with the load cable 30.

Another sensor element 52c is associated with the biasing member 112. The sensor element 52c detects the amount of force associated with contact between the load cable 30 and the impact members 102 and 104 by detecting the amount of movement of the corresponding portion of the biasing member 112. Given information about the force associated with the biasing of the biasing member 112, the amount of movement of the components of the biasing member 112 may be interpreted as the amount of force required to cause such movement. In another example, the sensor element 52c directly measures the force associated with overcoming the bias of the biasing member 112.

The example of fig. 3 also includes a sensor element 52d, such as a load cell or strain gauge, that detects the force exerted on the impact members 102 and 104 due to contact with the load cable 30.

The various sensor elements 52a-52d in fig. 3 may be used independently or in combinations of two or more of such sensor elements. The example of fig. 3 illustrates how a variety of different sensors can be incorporated into the damper device to provide feedback information regarding a sway condition that causes contact between the damper and the elongated member within the elevator system. This feedback information is useful for adjusting operating parameters of the elevator system 20.

One feature of the disclosed example is that the indication provided to the elevator controller 54 can be customized to meet the particular needs of a particular embodiment. For example, analog signal feedback may be used to provide amplitude information (e.g., amount of movement or amount of force) that is useful for making decisions regarding the severity of the sway condition. This may provide additional useful information compared to a digital arrangement in which only an indication that wobble has occurred may be provided. Of course, some implementations of the invention will include digital signal outputs from one or more sensors for implementing responsive adjustments in elevator system operation to address the sway condition. In at least one example, a combination of analog and digital signals is used. The ability to provide information regarding the severity of the sway condition allows for adjustment of the response of the elevator controller 54 to the current sway condition in the hoistway 26.

Any of the dampers 50, 60, 80 or 94 may have a configuration as shown in fig. 2 or 3. Of course, other configurations of those dampers are possible, and the present invention is not necessarily limited to the specific configuration of its own damper. Similarly, the placement or type of sensors 52 may vary from the disclosed examples to meet the needs of a particular embodiment.

In another example, one or more of the dampers 50, 60, 80, and 94 includes a rope shroud that is supported on the corresponding structure 53 or 84 to protect the ropes 30, 70, hoistway structures, or both from damage. Suitable ones of the disclosed example sensors are associated with the rope shroud damper to provide an indication of contact between the damper and the rope as described above. In some examples, such rope shroud dampers include a metal sheet and the sensor is associated with the metal sheet in a manner that the sensor detects at least one of impact vibration, force, or radiated noise.

The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.

Claims (16)

1. An elevator system, comprising:

a first mass movable within the hoistway;

a second mass movable within the hoistway;

a plurality of elongated members coupling the first mass to the second mass;

at least one damper selectively contacting at least one of the elongated members in response to lateral movement of the at least one of the elongated members;

a sensor that detects contact between the damper and the at least one of the elongated members, wherein the sensor provides an indication of at least one characteristic of the detected contact between the damper and the at least one of the elongated members;

a controller that controls at least one aspect of elevator system operation in response to detected contact, wherein the controller selects the at least one aspect of elevator system operation for adjustment based on a magnitude of the indication from the sensor, the at least one aspect including at least one of:

limiting the length of travel of an elevator to an upper or lower landing of the hoistway;

moving the elevator car to a designated point within the hoistway that is considered to be a vantage point during the sway condition;

causing the elevator car to go to a nearest landing and causing a door of the elevator car to open to allow passengers to exit the elevator car.

2. The elevator system of claim 1, wherein the sensor provides an indication of movement of the at least one damper resulting from contact with the at least one of the elongated members.

3. The elevator system of claim 2, wherein the sensor provides an indication of rotational movement of the damper.

4. The elevator system of claim 2, wherein the sensor provides an indication of lateral movement of the damper.

5. The elevator system of claim 2, wherein the sensor provides an indication of acceleration of the at least one damper.

6. The elevator system of claim 1, wherein the sensor detects a force exerted on a damper resulting from contact with the at least one of the elongated members, the sensor providing an output that is an indication of the detected force.

7. The elevator system of claim 1, wherein the sensor detects noise associated with contact between the damper and the at least one of the elongated members.

8. The elevator system of claim 1, wherein the at least one characteristic comprises at least one of a length of time during which contact is detected, a force exerted on the damper resulting from contact, or a number of times the detected contact occurs.

9. The elevator system of claim 1, wherein the damper comprises at least one of:

a rope sway mitigation damper supported at a selected location in the hoistway where the damper is useful for reducing sway of the elongate member, or

A rope shroud damper supported on a surface to protect against potential damage to the elongated member or the surface that might otherwise result from direct contact between the elongated member and the surface.

10. A method of responding to sway in an elevator system, the elevator system comprising at least one damper configured to selectively contact at least one elongate member if sway occurs, the method comprising the steps of:

sensing contact between the damper and the elongate member;

providing an indication of the sensed contact;

adjusting at least one aspect of elevator system operation based on the indicated magnitude, the at least one aspect including at least one of:

limiting the length of travel of the elevator to the upper or lower platforms of the hoistway;

moving the elevator car to a designated point within the hoistway that is considered to be a vantage point during the sway condition;

causing the elevator car to go to a nearest landing and causing a door of the elevator car to open to allow passengers to exit the elevator car.

11. The method of claim 10, comprising sensing lateral movement of the damper resulting from contact with the at least one elongate member.

12. The method of claim 10, comprising sensing rotational movement of the damper resulting from contact with the elongate member.

13. The method of claim 10, comprising sensing acceleration of the damper resulting from contact with the elongated member.

14. The method of claim 10, comprising providing an indication of at least one of a length of time during which contact is detected, a force exerted on the damper resulting from contact, or a number of times the detected contact occurred.

15. The method of claim 10, comprising sensing a force exerted on the damper resulting from contact with the elongate member.

16. The method of claim 10, comprising sensing noise associated with contact between the damper and the elongate member.