Elongation-based monitoring of tension members
By marking indicators on the tension members of the elevator system and providing replacement instructions according to length adjustment and stretching, the problem of high cost of suspension components in the prior art is solved, and the problem of insufficient inspection of suspension components is achieved cheaper, accurate and Reliable health monitoring effects.
Patent Information
- Application Number
- CN202411127341.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-08-21
- Filing Date
- 2024-08-16
- Publication Date
- 2025-02-21
AI Technical Summary
In existing elevator systems, the inspection method of suspension components is expensive, with insufficient accuracy and reliability, especially the inspection of coated tapes and coated ropes is difficult to achieve through traditional manual and visual methods.
By marking indicators on the tension member of the elevator system, the movement of the indicators provides a visual indication of replacing the tension member according to the length adjustment and stretching of the tension member, and adjusting the length of the tension member by monitoring the change of the buffer distance to achieve Health monitoring.
This method provides a cheaper, more accurate and more reliable tension component health monitoring system, which can effectively replace traditional resistance-based monitoring methods and improve inspection accuracy and reliability.
Smart Images
Figure CN119490119A_ABST
Abstract
Description
Background Art
[0001] For example, elevator systems are widely used to carry passengers between different floors in a building. Some elevator systems are traction-based, where a suspension assembly (sometimes called a rope) suspends the elevator car and counterweight. The suspension assembly also facilitates movement of the elevator car when necessary. Traditional suspension assemblies include round steel ropes. More recently, elevator systems have included other types of suspension members, such as flat belts or other types of ropes having tension members wrapped in a compressible polymer sheath.
[0002] Conventional round steel ropes are typically inspected using a manual process involving manual and visual observation of the condition of the outer surface of the rope. Coated belts and other coated ropes cannot be inspected in this manner. Electrical inspection techniques have been developed that involve applying an electrical current to at least some of the tension members and measuring an electrical characteristic, such as resistance, to obtain information indicative of the condition of the belt or coated rope. Alternative, more cost-effective inspection methods are sought to improve accuracy and reliability. Summary of the invention
[0003] An illustrative method includes marking at least one tension member with an indicator at a predetermined distance from a fixed point; adjusting the length of the at least one tension member to accommodate stretching; and replacing the at least one tension member when the indicator approaches the specified distance from the fixed point.
[0004] In addition to or as an alternative to one or more of the above features, the method includes waiting a predetermined time after installing the at least one tension member, during which the at least one tension member has an initial stretch, adjusting the length of the at least one tension member to accommodate the initial stretch, and then marking the at least one tension member with an indicator mark at a predetermined distance from the fixed point.
[0005] Additionally or alternatively to one or more of the above features, the method includes reducing the length of the at least one tension member during each adjustment and bringing the indicator mark closer to the fixing point.
[0006] Additionally or alternatively to one or more of the features described above, the predetermined distance from the fixed point is determined based on a plurality of elevator characteristics.
[0007] In addition to or in the alternative to one or more of the above characteristics, the plurality of elevator characteristics include one or more of a length of the tension member, an expected life of the tension member, test data, elevator system layout, and usage patterns.
[0008] In addition to or as an alternative to one or more of the above features, the elevator car is coupled to the counterweight via the at least one tension member, the method further comprising: after installation, setting an initial buffer distance between the bottom of the counterweight and a buffer mounted at the bottom of the hoistway; monitoring a decrease in the buffer distance as a result of the stretching; and during each adjustment, shortening the length of the at least one tension member until the bottom of the counterweight returns to the initial buffer distance.
[0009] Additionally or alternatively to one or more of the above features, during each adjustment, the method includes reducing the length of the at least one tension member, which brings the indicator mark closer to the fixed point.
[0010] Additionally or alternatively to one or more of the above features, the fixing point is at an upper end of at least one tension member.
[0011] An illustrative example elevator system includes: an elevator car capable of moving within a hoistway; at least one tension member that supports the elevator car and facilitates movement of the elevator car in the hoistway; and an indicator mark that is located on the at least one tension member at a predetermined distance from a fixed point, and wherein a visual indication of tension member replacement is provided when the indicator mark approaches the specified distance from the fixed point after the tension member length is adjusted.
[0012] In addition to or in the alternative to one or more of the above features, the at least one tension member has an initial installation condition, and wherein an indicator mark is marked on the at least one tension member after a predetermined time has passed from the initial installation condition, during which the at least one tension member has been adjusted to accommodate the initial stretch.
[0013] Additionally or alternatively to one or more of the above features, during each adjustment, the at least one tension member is reduced in length and the indicator mark is brought closer to the fixing point.
[0014] Additionally or alternatively to one or more of the features described above, the predetermined distance from the fixed point is determined based on a plurality of elevator characteristics.
[0015] In addition to or in the alternative to one or more of the above characteristics, the plurality of elevator characteristics include one or more of a length of the tension member, an expected life of the tension member, test data, elevator system layout, and usage patterns.
[0016] In addition to or as an alternative to one or more of the above features, the elevator car is coupled to the counterweight via the at least one tension member, and wherein: after installation, an initial buffer distance between the bottom of the counterweight and a buffer mounted at the bottom of the hoistway is set; a decrease in the initial buffer distance as a result of stretching is monitored to provide a current buffer distance; and after each adjustment, the length of the at least one tension member includes a shortened length and the bottom of the counterweight is at the initial buffer distance.
[0017] Additionally or alternatively to one or more of the above features, after each adjustment, the length of the at least one tension member is reduced, which brings the indicator mark closer to the fixing point.
[0018] The various features and advantages of example embodiments 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. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 Selected portions of an elevator system incorporating a monitoring system of the present disclosure are schematically illustrated.
[0020] Figure 2 is a flow chart describing a method of monitoring tension members in an elevator system. DETAILED DESCRIPTION
[0021] Embodiments of the present disclosure provide elongation-based health monitoring of tension members of an elevator system. The health monitoring system is cheaper, more accurate, and more reliable than resistance-based monitoring of tension members.
[0022] Figure 1 Selected portions of an elevator system 20 are schematically illustrated. An elevator car 22 is supported by a rope arrangement or suspension assembly 24 that includes a plurality of tension members 26. Figure 1 A 2:1 rope system is shown; however, other rope systems, such as a 1:1 rope system, for example, may also be applied. Elevator car 22 is coupled to counterweight 28 via tension member 26. Machine 30 includes a traction sheave 32 for controlling movement of the elevator car. When tension member 26 moves in response to rotation of traction sheave 32, elevator car 22 and counterweight 28 move vertically. Tension member 26 moves around sheave 34 as elevator car 22 moves between landings or floors. In one example, tension member 26 includes a coated rope or a coated steel belt.
[0023] In one example, an elongation-based health monitoring system is provided to monitor the health of the tension members 26 of the elevator system 20. In one example, the health monitoring system is activated for each new installation of the elevator system 20 in a building. For example, each new installation includes installing at least one tension member 26 that facilitates movement of the elevator car 22 within the hoistway 36. The tension member has a fixed point C and extends along a length L. After installation, a predetermined distance A from the fixed point C is determined. Figure 2 As shown in the example method of FIG. 1 , the tension member 26 is marked with an indicator mark B at a predetermined distance A from the fixed point C, as indicated at 100. In one example, over time, the tension member 26 will stretch a small amount, which will cause the indicator mark B to move downward away from the initial predetermined distance A. In addition, the stretching caused by the weight will cause a decrease in the cushioning distance, as will be discussed in more detail below.
[0024] During maintenance or repair operations, the length of the tension member 26 is adjusted (i.e., shortened) to accommodate this stretching, such as Figure 2 In one example, as indicated at 200, during a conditioning maintenance operation, when the indicator mark B approaches a specified distance from the fixed point C, the tension member 26 is replaced. This provides a visual indication of the health of the tension member 26.
[0025] In one example, the fixing point C is at the upper end 38 of the tension member 26. The opposite end 40 of the tension member is also at a fixing point.
[0026] In one example, after the tension members 26 are installed, an initial predetermined amount of time is allowed to pass. During this predetermined amount of time, the tension members 26 have an initial amount of stretch that occurs due to the type of elevator system, the weight of the components, etc. In one example, before marking the tension members 26 with indicator marks B at a predetermined distance from the fixed point C, the length of the tension members 26 is adjusted to accommodate the initial stretch. In one example, after the tension adjustment is configured, the indicator marks B are placed on each tension member 26 at a specified distance in the range of, for example, 300 mm to 500 mm. It should be understood that the location of the indicator marks B depends on factors such as, for example, the type of tension member, the type of elevator system, the expected life, etc.
[0027] As discussed above, during each adjustment, the length of the tension member 26 is reduced to accommodate the stretch. In one example, the length of the tension member is shortened by cutting the tension member. This brings the indicator mark B closer to the fixed point C during each adjustment cycle. During adjustment, once the indicator mark B reaches the fixed point C, or approaches a specified distance from the fixed point C, it is a visual indication that the tension member needs to be replaced.
[0028] A buffer 50 is installed at the bottom of the hoistway 36. In one example, the buffer 50 includes one or more resilient members, such as helical steel springs, located in this area for buffering purposes. In one example, after installation, an initial buffer distance D between the bottom of the counterweight 28 and the top of the buffer 50 is defined. In one example, the buffer distance D can be measured under specific conditions, which is the position of the tank associated with the buffer when on the highest floor. As a result of the stretching, a decrease in the buffer distance D occurs over time. For example, this decrease can be monitored by the sensor 42 or other device. Figure 1 A schematic representation of sensor 42 is shown. In one example, sensor 42 is positioned within hoistway 36 at a location adjacent the bottom of counterweight 28 to monitor buffer distance D. In one example, during each adjustment, the length of tension member 26 is shortened until the bottom of counterweight 28 returns to the initial buffer distance D.
[0029] In one example, the health monitoring system includes one or more processors 44 configured to facilitate determining the condition of each tension member 26. The processor 44 in the illustrated example includes one or more computing devices and associated memory. The processor 44 is programmed or otherwise configured to use different types of information (indicative of the respective conditions of the tension members 26) and combinations of criteria to facilitate determining when it is desirable or necessary to remove any of the tension members 26 from service.
[0030] In one example, sensor 42 transmits information about the buffer distance to processor 44. During maintenance or repair operations, this information can be retrieved from processor 44 so that the length of tension member 26 can be adjusted until the bottom of counterweight 28 returns to the initial buffer distance D. Thus, during each adjustment, buffer distance D is brought to the same initial value, and the length of the belt is adjusted to bring point B closer to C. Alternatively, the buffer distance can be measured manually during each repair operation.
[0031] In one example, the predetermined distance A from the fixed point C is determined based on a plurality of elevator characteristics. For example, the plurality of elevator characteristics include one or more of the length of the tension member, the expected life of the tension member, test data, elevator system layout, and usage patterns. The processor 44 may use this information to facilitate determining the predetermined distance A from the fixed point C. For example, the predetermined distance A is calculated by a software model that takes into account characteristics such as test data, elevator system layout, usage patterns, etc. The processor 44 may be a remote processor, or a processor of the elevator system, or a combination of both. Those skilled in the art who have the benefit of this description will be able to determine the predetermined distance A from the fixed point C for each respective elevator system 20.
[0032] The subject disclosure provides a health monitoring system that has determined the correlation between elongation and residual strength of tension members. Testing has shown that the elongation of the tension member 26 during and after testing has a much better correlation with the loss of breaking force than other methods (including resistance-based methods). During inspection, when adjustment is required to bring the counterweight 28 to its original position, the length of each tension member is corrected to eliminate the accumulated stretch. At this time, the load on each tension member is adjusted according to specifications. The correction of each tension member length will cause the mark B to move closer to the terminal end of each tension member. At a certain point, the mark B on one or more tension members will reach the terminal fixing point C. At this point in time, the tension member(s) and the remaining tension members should be replaced because one or more tension members have reached a point that is considered to be the end of life and should therefore be removed. The subject disclosure solves the problems with resistance-based methods, particularly those related to cost, reliability, and accuracy.
[0033] The foregoing description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiments may become apparent to those skilled in the art that do not necessarily depart from the essence of the invention. The scope of legal protection afforded this invention can only be determined by studying the following claims.
Claims
1. A method comprising: marking at least one tension member with an indicator mark at a predetermined distance from the fixed point; adjusting the length of the at least one tension member to accommodate stretching; and When the indicator mark approaches a designated distance from the fixed point, the at least one tension member is replaced.
2. The method according to claim 1 includes waiting a predetermined time after installing the at least one tension member, during which the at least one tension member has an initial stretch, adjusting the length of the at least one tension member to accommodate the initial stretch, and then marking the at least one tension member with the indicator mark at the predetermined distance from the fixed point.
3. The method of claim 1, comprising reducing the length of the at least one tension member and bringing the indicator mark closer to the fixing point during each adjustment.
4. The method according to claim 1, wherein: The predetermined distance from the fixed point is determined based on a plurality of elevator characteristics.
5. The method according to claim 4, wherein: The plurality of elevator characteristics include one or more of a length of the tension member, an expected life of the tension member, test data, an elevator system layout, and a usage pattern.
6. The method according to claim 4, wherein: The elevator car is coupled to the counterweight via the at least one tension member, the method further comprising: After installation, setting an initial buffer distance between the bottom of the counterweight and a buffer installed at the bottom of the hoistway; monitoring a decrease in the buffer distance as a result of the stretching; and During each adjustment, the length of the at least one tension member is shortened until the bottom of the counterweight returns to the initial buffer distance.
7. The method according to claim 6, wherein: During each adjustment, the method includes reducing the length of the at least one tension member, which brings the indicator mark closer to the fixing point.
8. The method according to claim 6, wherein: The fixing point is at an upper end of the at least one tension member.
9. An elevator system, comprising: An elevator car capable of moving within a hoistway; at least one tension member that supports the elevator car and facilitates movement of the elevator car in the hoistway; as well as An indicator mark is located on the at least one tension member at a predetermined distance from the fixing point, and wherein after the tension member length is adjusted, when the indicator mark approaches the specified distance from the fixing point, a visual indication of tension member replacement is provided.
10. The elevator system according to claim 9, wherein: The at least one tension member has an initial installation condition, and wherein the indicator mark is marked on the at least one tension member after a predetermined time has passed from the initial installation condition, during which the at least one tension member has adjusted to accommodate initial stretching.
11. The elevator system according to claim 9, wherein: During each adjustment, the length of the at least one tension member decreases and the indicator mark is brought closer to the fixing point.
12. The elevator system according to claim 9, wherein: The predetermined distance from the fixed point is determined based on a plurality of elevator characteristics.
13. The elevator system according to claim 12, wherein: The plurality of elevator characteristics include one or more of a length of the tension member, an expected life of the tension member, test data, an elevator system layout, and a usage pattern.
14. The elevator system according to claim 9, wherein: The elevator car is coupled to a counterweight via the at least one tension member, and wherein: After installation, setting an initial buffer distance between the bottom of the counterweight and a buffer installed at the bottom of the hoistway; monitoring a decrease in the initial buffer distance as a result of the stretching to provide a current buffer distance; and After each adjustment, the length of the at least one tension member includes a shortened length and the bottom of the counterweight is at the initial buffer distance.
15. The elevator system according to claim 14, wherein: After each adjustment, the length of the at least one tension member is reduced, which brings the indicator mark closer to the fixing point.