Patent Application
20150239708
The present invention generally relates to magnetic hoisting member monitoring, and more particularly, but not exclusively, to monitoring a magnetic hoisting member with giant magneto-resistance sensors. Present approaches to magnetic hoisting member monitoring suffer from a variety of drawbacks, limitations, disadvantages and problems including those respecting real time testing, non-destructive tests and others. There is a need for the unique and inventive magnetic hoisting member monitoring apparatuses, systems and methods disclosed herein.
One embodiment of the present invention is a unique apparatus and method for magnetic hoisting member monitoring. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for magnetic hoisting member monitoring. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.
It is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements.
The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown.
The following description of certain examples of the invention should not be used to limit the scope of the present invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive
With reference to
In various applications, a tension unit can include aids for creating tension in a hoisting member. The tension created provides a degree of travel control of the hoisting member and, thereby, travel control of the elevator car. A tension unit can include a passive weight system such as a counterweight or another car. Alternatively, a tension unit can include a mechanical tensioning system such as a spring system or a high traction system with grooved belt and spool designs, for example. For instance, in some versions elevator system 100 can be configured as a drum elevator, where the hoisting member is wound and unwound about a drum to raise and lower the car through the hoistway. Still in some other versions, elevator system 100 can be configured as a roped hydraulic elevator system where a tension unit is used with a hydraulic drive by having the car connected with the tension unit via a hoisting member. In view of the teachings herein, other configurations for elevator system 100 will be apparent to those of ordinary skill in the art.
In the present example, the hoisting member 130 includes at least one load bearing member or rope encased within a common coating. The at least one load bearing member is made up of a plurality of wires and contains a magnetic material. In some embodiments, the hoisting member is implemented as a suspension member. In other embodiments, the hoisting member is implemented as a transmission member, for instance in some examples as a cog belt. Still in some versions the hoisting member is implemented as both a suspension member and a transmission member.
Suspension members operate under tension balancing the weight of the elevator car with the tension unit. As such, suspension members can be referred to as tension members. Suspension members can include, among others, coated flat belts or coated steel wire ropes. Coated suspension members can include magnetic load bearing members coated with a polyurethane material or other envelope or matrix material. In some versions suspension members are not required to be coated.
Analyzing the structural integrity and remaining life of a hoisting member is a function of the safe operation of an elevator system. Integrity degradation of a hoisting member can, as one example, result from cyclic bending around sheaves when the elevator car is translated through the hoistway. The hoisting member can be monitored for integrity degradation. Visual inspection methods for monitoring hoisting members can be limited by an outer portion or coating of the hoisting members. The load bearing members of coated hoisting members can experience damage that is not detected with visual inspection. An embodiment of the present application includes a monitoring system having a magnetic field producer and a giant magneto-resistance (GMR) sensor unit capable of evaluating irregularities and indicating a level or degree of integrity for a magnetic hoisting member which can be coated, or in some instances uncoated. The GMR sensor unit can be a single sensor or an array of sensors.
An embodiment of the present application is capable of identifying the position of an irregularity in a coated magnetic hoisting member along the hoisting member's length, width, and depth. Irregularities can include diameter diminution of cables or wires, broken wires due to fretting wear and stress fatigue, holes, voids, roughing, corrosion, fractures, deformation, and manufacturing defects. A monitoring system of the present application is capable of detecting and determining a degree of irregularity or damage. In some embodiments, the identified area can be further inspected for the type and degree of irregularity. Targeted investigations as a result of this embodiment can reduce the amount of investigation necessary for identifying defects or damage in magnetic hoisting members embedded in or surrounded by matrix materials and for determining the integrity of a length of the hoisting member.
For an embodiment shown in
Various embodiments of the monitoring system can include an instrumentation amplifier 250, a control unit 260, and an indicator system 270. In one embodiment, the amplifier 250 can amplify a signal produced by the GMR sensor unit 220 in response to the variations in the magnetic field 240. The amplified signal can be transmitted to a control unit 260. The control unit 260 can store information regarding a signal from the GMR sensor unit 220 or activate the indicator system 270 to communicate a representation of the GMR signal. In the version of
In an embodiment shown in
In a further embodiment, the monitoring unit shown in
In one embodiment of the present application, a magnetic field producer can include a permanent magnet and a magnetic conductor. In a specific embodiment, the magnets can include an Nd—Fe—B type magnet. In another embodiment, the magnets can have no energy requirement to activate a magnetic field. The magnetic field producer can alternatively or additionally include an electromagnet to induce a magnetic field where the induced magnetic field can be adjusted by increasing or decreasing the coil current.
One embodiment of the present application includes a magnetic field producer with permanent magnets. The magnetic field producer can be positioned on a housing unit and the permanent magnets of the magnetic field producer can be spaced apart with a metal plate to complete a magnetic flux loop. A GMR sensor array can be aligned approximate to the center of the magnetic field produced by the magnetic field producer. Positioning features of the housing unit can guide a moving hoisting member. The housing unit can be placed against the hoisting member or in close proximity without complex guiding features. In some versions the hoisting member and housing unit are configured such that hoisting member moves through a space within the housing unit. A magnetic portion of the hoisting member interacts with the magnetic field from the magnetic field producer when the reluctance of the magnetic portion of the hoisting member is lower than that of air. By way of example only, and not limitation, in a specific embodiment, the hoisting member includes a steel wire where the reluctance is much lower than air, e.g. on the order of a few thousand times lower than air.
Magnetic flux lines representing the magnetic field produced by the magnetic field producer can pass through the hoisting member. The pattern of the magnetic flux lines can be influenced by the shape and geometry of the magnetic portions of the hoisting members. Localized flaws in the magnetic portions of a hoisting member can cause the magnetic flux to leak at the site of the flaw. Magnetic flux leakage can be sensed by the GMR sensor unit 220. In various embodiments, the GMR sensors 222 can generate an output signal 223 in response to changes in the flux pattern created by irregularities in the magnetic hoisting members 230. The output signal 223 from the GMR sensors 222 can be conditioned and amplified by an instrumentation amplifier 250 to produce an amplified output signal 224. The output signal 223 and/or amplified output signal 224 can be stored for retrieval and produce an indication signal 262 for the activation of an LED indicator to indicate damage or deformity in the hoisting member. To determine the degree of irregularity in a hoisting member, an algorithm for determining the remaining life of a hoisting member can be implemented by a control unit 260 in response to the output signal and a determination regarding the integrity of the hoisting member can be stored or communicated directly. Based on the number of irregularities and/or the extent of magnetic flux leakage, the control unit can determine when the breaking strength of a hoisting member falls below a predetermined threshold, for example 60% breaking strength for the entire hoisting member. Based upon the degree of irregularity indicated, a magnetic hoisting member can be further inspected.
A GMR sensor unit in another embodiment can detect flaws in a magnetic load-bearing member based on changes in its magnetic field structure. A GMR sensor or sensor array is capable of detecting magnetic flux leakage resulting from irregularities, localized flaws, loss of metallic cross-sectional area, and loss of metallic volume defects in magnetic load-bearing members encapsulated in a matrix material of a hoisting member. A GMR sensor unit can include a single sensor or an array of sensors. Selection of the size of a GMR sensor array in a GMR sensor unit can be in response to the number, size and geometry of the hoisting member or members being evaluated.
A GMR sensor unit 220 can include an array of sensors 222 as shown in
Giant magneto-resistance is a quantum mechanical magneto-resistance effect observed in a multi-layered thin-film structure. The thin films alternate between ferromagnetic and non-magnetic materials. When a magnetic field is present, the electrical resistance of the layered structure decreases significantly due to the spinning or scattering of electrons in the layers. The GMR effect can operate through non-magnetic materials such as polyurethane coatings, for example. The GMR effect can therefore be applied to magnetic materials coated with or encapsulated in a non-magnetic matrix.
For an embodiment of the present application, a GMR sensor unit is positioned relative to a magnetic load bearing member. The axis of sensitivity of the GMR sensor is orthogonal to the longitudinal axis of the load-bearing member. This arrangement can be optimized for the GMR sensor to process signals indicating leaking flux.
In a specific embodiment, the GMR sensor can be encapsulated in a standard SOIC-8 package and be configured into a Wheatstone bridge. In another specific embodiment, the GMR sensor includes parameters such as a saturation field of 20 Oe, a linear range of 2.014 Oe, a sensitivity of 2-3.2 mV/V-Oe, a resistance of 5 k±20% ohms, SOIC-8 packaging, and a die size of 436×3370 μm.
A GMR sensor 222 can generate signals which can be conditioned and/or amplified by an instrumentation amplifier 250. In a further embodiment, an amplifier or array of amplifiers can be included with a GMR sensor unit to amplify sensor output. With an amplifier and GMR sensor mounted on a circuit board, the change in magnetic field can be amplified to provide information relating to the integrity of the magnetic portions of a hoisting member. An instrumentation amplifier can allow for differential input and reduce common mode noise. In one embodiment, an amplifier can be an integrated, micro-power instrumentation amplifier with a high common mode rejection ratio allowing the setting of gain with a single external resistor.
In another embodiment, the monitoring system can include a signal generator 280 to deliver signals from a GMR sensor unit 220 to a control unit 260. The control unit 260 can also receive information from other systems including hoisting member location or position relative to the monitoring system. The control unit 260 can include storage medium 261 to store received information for concurrent processing or processing at a later time. The control unit 260 can further communicate signals, e.g. indication signals, to provide an indication to an operator or maintenance schedule indicating the location of any changes in the magnetic field produced by the monitoring system and/or the degree of irregularity in the hoisting member. Communication can include, but is not limited to, telephone lines, cellular communications, Bluetooth transmission and Wi-Fi and can further include streaming data to electronic devices, such as but not limited to, handhelds, computers, smart phones etc. The communication can be through secure communication protocols.
An output signal of a GMR sensor 222 can be used to broadcast the existence and location of a flaw in a magnetic portion of a hoisting member 230 passing through a magnetic field. An output signal broadcast can include communication with a controller 260 or directly indicate the existence and location of the flaw with an indicator system 270 through audible signals, user interface systems, and visual systems such as LEDs, for example. The exemplary LEDs can be driven by an output of an amplifier signal and turned on at the exact location of the flux leakage site along the magnetic load-bearing member. In another embodiment, a controller 260 can directly signal changes in magnetic field readings with indicators 270 local to the monitoring system. Such indicators 270 can include, but are not limited to, indicator lights and LEDs on a housing unit 300 relative to a hoisting member 230 for at least a portion of the monitoring system as shown in
An embodiment in
Hand tool 1000 is configured with a handle 1002 and a U-shaped recess 1004. Handle 1002 is located on hand tool 1000 in a location that makes hand tool 1000 easy to grasp. In the illustrated version, but not required in all versions, handle 1002 is located on the opposite side of recess 1004. Recess 1004 is configured with a shape, in this example a U-shape, that complements the shape of hoisting member 230. In the illustrated version hoisting member 230 is configured as a flat belt and this fits within U-shaped recess 1004 such that recess 1004 guides hoisting member 230. In the present example, the sidewalls 1006 of housing 1008 of tool 1000 that define U-shaped recess 1004 serve as positioning members that guide hoisting member 230 as it passes by tool 1000. In the present example, hoisting member 230 is guided by the three sidewalls 1006 of housing 1008 that define recess 1004. In other versions a greater or fewer number of positioning members can be used to guide hoisting member 230. In view of the teachings herein, other ways to guide and/or position hoisting member 230 relative to tool 1000 or housing 1008 of tool 1000 will be apparent to those of ordinary skill in the art.
In the present example, within hand tool 1000, the device includes one or more GMR sensors 222, a magnetic field producer 210, an instrumentation amplifier 250, a control unit 260, and an indicator system 270 as shown in
In the present example, within device 2000 are one or more GMR sensors 222, a magnetic field producer 210, an instrumentation amplifier 250, a control unit 260, and an indicator system 270 as shown in
In the present examples, within each of device 3000 and device 4000 are one or more GMR sensors 222, a magnetic field producer 210, an instrumentation amplifier 250, a control unit 260, and an indicator system 270 as shown in
In the present example, within device 5000 are one or more GMR sensors 222, a magnetic field producer 210, an instrumentation amplifier 250, a control unit 260, and an indicator system 270 as shown in
As described and shown in the above examples, monitoring system 200 is configured to monitor a hoisting member in either a stationary or moving state. Moreover, monitoring system 200 is configured to monitor the integrity of a hoisting member when the hoisting member is in use with an elevator system. In other words, monitoring system 200 provides continuous monitoring of a moving hoisting member used in driving an elevator. As described, this monitoring includes continuous monitoring of magnetic flux leakage attributed to one or more flaws, irregularities, or imperfections in a hoisting member. In such cases with an elevator system equipped with monitoring system 200, monitoring system 200 is configured such that a majority of the hoisting member is positionable proximate to monitoring system 200, i.e. GMR sensor unit 220, during operation of the elevator system. Also as shown and described, monitoring system 200 is configured to detect imperfections within interior components of a hoisting member, and without necessarily contacting the hoisting member directly. Furthermore, monitoring system 200 is configured to accomplish this while having a generally perpendicular orientation with the hoisting member. Also, in some versions, monitoring system 200 is configured along a portion of hoisting member between the ends of hoisting member and/or between the termination devices that hold hoisting member. In such versions a system for monitoring is provided where it is not required to expose the ends of the hoisting member to the monitoring system.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.
