Patent Application
20120126794
The present application relates generally to power systems and, more particularly, to a sensor assembly and methods of assembling a sensor probe.
Known machines may exhibit vibrations and/or other abnormal behavior during operation. One or more sensors may be used to measure and/or monitor machine operation and to determine, for example, an amount of vibration exhibited in a machine drive shaft, a rotational speed of the machine drive shaft, and/or any other suitable operational characteristic of an operating machine or motor. Often, known sensors are coupled to a machine monitoring system that includes a plurality of monitors. The monitoring system receives signals representative of measurements from one or more sensors, performs at least one processing step on the signals, and then transmits the modified signals to a diagnostic platform that displays the measurements to a user.
At least some known machines use one or more proximity sensors and/or sensor probes to measure a vibration and/or a position of a machine component. Known proximity sensors are typically manufactured as a single integrated component, for example, using an injection molding process. More specifically, in at least some known sensors, a probe tip is injection molded such that the tip includes one or more sensing elements that are encapsulated therein. However, such a fabrication process may be expensive and/or may involve complicated manufacturing steps and/or machinery. Moreover, because the unit is an integrated component, if one element of the proximity sensor is faulty or damaged, the entire sensor may need to be replaced.
In one embodiment, a method of assembling a sensor probe is provided that includes positioning an emitter within a probe cap, wherein the emitter is configured to generate an electromagnetic field from at least one microwave signal. An inner sleeve is coupled to the probe cap and an outer sleeve is coupled to the inner sleeve.
In another embodiment, a sensor probe is provided that includes an emitter configured to generate an electromagnetic field from at least one microwave signal, a probe cap sized to receive the emitter, an inner sleeve coupled to the probe cap, and an outer sleeve coupled to the inner sleeve.
In yet another embodiment, a sensor assembly is provided that includes at least one probe. The at least one probe includes an emitter configured to generate an electromagnetic field from at least one microwave signal, a probe cap sized to receive the emitter, an inner sleeve coupled to the probe cap, and an outer sleeve coupled to the inner sleeve. The microwave sensor assembly also includes a signal processing device coupled to the at least one probe. The signal processing device is configured to generate a proximity measurement based on a loading induced to the emitter.
In the exemplary embodiment, drive shaft 104 is at least partially supported by one or more bearings (not shown) housed within machine 102 and/or within load 106. Alternatively or additionally, the bearings may be housed within a separate support structure 108, such as a gearbox, or within any other structure or component that enables power system 100 to function as described herein.
In the exemplary embodiment, power system 100 includes at least one sensor assembly 110 that measures and/or monitors at least one operating condition of machine 102, of drive shaft 104, of load 106, and/or of any other component of power system 100 that enables system 100 to function as described herein. More specifically, in the exemplary embodiment, sensor assembly 110 is a proximity sensor assembly 110 that is positioned in close proximity to drive shaft 104 for measuring and/or monitoring a distance (not shown in
During operation, in the exemplary embodiment, the operation of machine 102 may cause one or more components of power system 100, such as drive shaft 104, to change position with respect to at least one sensor assembly 110. For example, vibrations may be induced to the components and/or the components may expand or contract as the operating temperature within power system 100 changes. In the exemplary embodiment, sensor assemblies 110 measure and/or monitor the proximity, the position, and/or the amount of vibration of the components relative to each sensor assembly 110 and transmit a signal representative of the measured proximity, position, and/or amount of vibration of the components (hereinafter referred to as a “proximity measurement signal”) to diagnostic system 112 for processing and/or analysis.
In the exemplary embodiment, signal processing device 200 includes a directional coupling device 210 that is coupled to a transmission power detector 212, to a reception power detector 214, and to a signal conditioning device 216. Moreover, in the exemplary embodiment, signal conditioning device 216 includes a signal generator 218, a subtractor 220, and a linearizer 222. Emitter 206 emits an electromagnetic field 224 when a microwave signal is transmitted through emitter 206.
During operation, in the exemplary embodiment, signal generator 218 generates at least one electrical signal with a microwave frequency (hereinafter referred to as a “microwave signal”) that is equal or approximately equal to at least one resonant frequency of emitter 206. Signal generator 218 transmits the microwave signal to directional coupling device 210. Directional coupling device 210 transmits a portion of the microwave signal to transmission power detector 212 and the remaining portion of the microwave signal to emitter 206. As the microwave signal is transmitted through emitter 206, electromagnetic field 224 is emitted from emitter 206 and out of probe housing 208. If an object, such as a drive shaft 104 or another component of machine 102 (shown in
In the exemplary embodiment, reception power detector 214 determines an amount of power based on and/or contained within the detuned loading signal and transmits a signal representative of the detuned loading signal power to signal conditioning device 216. Moreover, transmission power detector 212 determines an amount of power based on and/or contained within the microwave signal and transmits a signal representative of the microwave signal power to signal conditioning device 216. In the exemplary embodiment, subtractor 220 receives the microwave signal power and the detuned loading signal power, and calculates a difference between the microwave signal power and the detuned loading signal power. Subtractor 220 transmits a signal representative of the calculated difference (hereinafter referred to as a “power difference signal”) to linearizer 222. In the exemplary embodiment, an amplitude of the power difference signal is proportional, such as inversely or exponentially proportional, to a distance 226 defined between the object, such as drive shaft 104, within electromagnetic field 224 and probe 202 and/or emitter 206 (i.e., distance 226 is known as the object proximity). Depending on the characteristics of emitter 206, such as, for example, the geometry of emitter 206, the amplitude of the power difference signal may at least partially exhibit a non-linear relationship with respect to the object proximity.
In the exemplary embodiment, linearizer 222 transforms the power difference signal into a voltage output signal (i.e., the “proximity measurement signal”) that exhibits a substantially linear relationship between the object proximity and the amplitude of the signal. Moreover, in the exemplary embodiment, linearizer 222 transmits the proximity measurement signal to diagnostic system 112 (shown in
In the exemplary embodiment, probe cap 300 includes a substantially cylindrical end wall 308 that has an upstream surface 310 and an opposing downstream surface 312. Probe cap 300 also includes a substantially annular sidewall 314 that circumscribes upstream surface 310. Sidewall 314 includes an outer surface 316 and an opposing inner surface 318 that at least partially defines cavity 306. In the exemplary embodiment, probe cap 300 is substantially symmetric with respect to a centerline axis 320 extending through probe housing 208 when probe housing 208 is assembled. More specifically, sidewall 314 is spaced substantially equidistantly about centerline axis 320.
In the exemplary embodiment, probe cap 300 includes a threaded portion 322 that circumscribes inner surface 318. Probe cap 300, in the exemplary embodiment, is manufactured from a polyketone material, such as polyether ether ketone (PEEK), and/or any other material and/or compound that enables probe cap 300 to be positioned within an industrial environment and/or within machine 102 without substantial degradation during operation of power system 100 (both shown in
In the exemplary embodiment, inner sleeve 302 is annular and is sized to be at least partially received within probe cap 300. Inner sleeve 302 includes an outer surface 324 and an opposing inner surface 325. In the exemplary embodiment, inner sleeve 302 includes a threaded portion 326 that circumscribes outer surface 324. Threaded portion 326 cooperates with probe cap threaded portion 322 to enable probe cap 300 and inner sleeve 302 to be threadably coupled together. In the exemplary embodiment, inner sleeve 302 is manufactured from a substantially non-conductive material, such as a thermoplastic material or any other plastic material. As such, inner sleeve 302 facilitates electromagnetically isolating emitter 206 from outer sleeve 304 and/or from any portion of machine 102 that is adjacent to probe 202. Alternatively, inner sleeve 302 may be manufactured from any material and/or compound that enables probe 202 to function as described herein.
Outer sleeve 304, in the exemplary embodiment, is annular and is sized to at least partially receive inner sleeve 302 therein. Outer sleeve 304 includes an inner surface 328 and an opposing outer surface 330. In the exemplary embodiment, outer sleeve 304 includes an inner threaded portion 332 that circumscribes inner surface 328, and an outer threaded portion 334 that circumscribes outer surface 330. Inner threaded portion 332 cooperates with inner sleeve threaded portion 326 to enable inner sleeve 302 to be threadably coupled at least partially within outer sleeve 304. Outer threaded portion 334 is sized and shaped to cooperate with a threaded bore (not shown) formed within a machine, such as machine 102. As such, when probe 202 is assembled, probe 202 may be threadably coupled within machine 102, such that probe 202 is positioned proximate to a machine component to be measured and/or monitored. Alternatively, outer sleeve 304 may be fabricated substantially smoothly and/or may not include outer threaded portion 334 such that probe 202 and/or outer sleeve 304 may be coupled to machine 102 via one or more bolts, brackets, and/or any other coupling mechanism that enables power system 100 (shown in
In the exemplary embodiment, an emitter assembly 336 is positioned within probe housing 208 to form probe 202. More specifically, in the exemplary embodiment, within emitter assembly 336, emitter 206 is coupled to an emitter body 338. Emitter body 338 includes an upstream surface 340 and an opposing downstream surface 342. In the exemplary embodiment, emitter body 338 is a substantially planar printed circuit board (PCB), and emitter 206 includes one or more traces and/or other conduits (not shown) that are formed integrally with, and/or coupled to, emitter body downstream surface 342. Alternatively, emitter 206 and/or emitter body 338 may have any other construction and/or configuration that enables probe 202 to function as described herein. A coupling device 344 couples emitter body 338 and emitter 206 to a data conduit, such as to data conduit 204 for use in transmitting and receiving signals to and from signal processing device 200 (shown in
In the exemplary embodiment, in operation, probe cap 300 is positioned such that downstream surface 312 faces the object being measured and/or monitored. As such, an electromagnetic field 224 (shown in
During assembly, emitter assembly 336 is formed by coupling data conduit 204 to emitter body upstream surface 340 and to emitter 206 via coupling device 344. Emitter assembly 336 is positioned at least partially within probe cap 300. More specifically, emitter body 338 is positioned within cavity 306 such that emitter body downstream surface 342 and emitter 206 face end wall upstream surface 310. Inner sleeve 302 is inserted within cavity 306 and is positioned about data conduit 204. Moreover, inner sleeve 302 is threadably coupled to probe cap 300 via threaded portions 326 and 322. As inner sleeve 302 is threadably coupled to probe cap 300, an annular edge 346 of inner sleeve 302 contacts emitter body upstream surface 340 and urges downstream surface 342 of emitter body 338 into contact with end wall upstream surface 310. Threaded portions 322 and 326 cooperate to enable inner sleeve 302 to maintain emitter body 338 in contact with end wall 308 during operation of probe 202.
Outer sleeve 304 is threadably coupled to inner sleeve 302 such that outer sleeve 304 at least partially encloses inner sleeve 302. More specifically, when probe 202 is assembled, probe cap 300 and outer sleeve 304 enclose inner sleeve 302. Moreover, probe cap 300, outer sleeve 304, and inner sleeve 302 enclose at least a portion of data conduit 204. As such, in the assembled state, probe housing 208 substantially seals cavity 306 to facilitate protecting emitter 206 from damage. While one or more gaps 348 may be illustrated in
An inner sleeve is threadably coupled 406 to the probe cap, and an outer sleeve is threadably coupled 408 to the inner sleeve. As the inner sleeve is coupled 406 to the probe cap, the inner sleeve urges 410 the emitter into contact with the probe cap. In the exemplary embodiment, the inner sleeve, the outer sleeve, and the probe cap are substantially hollow such that a cavity is at least partially defined by the inner sleeve, the outer sleeve, and the probe cap. A data conduit is extended 412 through the inner sleeve, through the outer sleeve, and through at least a portion of the probe cap (i.e., through the cavity), and the data conduit is coupled 414 to the emitter. In the exemplary embodiment, the data conduit is configured to transmit at least one microwave signal to the emitter to enable the emitter to generate an electromagnetic field. The microwave probe measures a proximity of an object, such as a machine component, relative to the emitter, as described more fully above.
As compared to known probes, the exemplary probe described herein may be manufactured and/or assembled in a cost-effective and reliable manner. The probe cap, inner sleeve, outer sleeve, and emitter assembly may be manufactured separately. As such, machinery used to manufacture the probe described herein may be reduced in complexity and/or cost. Moreover, the exemplary probe described herein may be quickly and easily assembled and installed in a machine with minimal tools. If a component of the probe is faulty or is damaged, the probe may be disassembled and the component may be replaced, in contrast with known probes that are fabricated as a single component. As such, the probe described herein facilitates reducing a cost and a complexity of a sensor assembly and a power system that use the probe.
Exemplary embodiments of a sensor assembly and methods for assembling a sensor probe are described above in detail. The methods and sensor assembly are not limited to the specific embodiments described herein, but rather, components of the sensor assembly and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the sensor assembly may also be used in combination with other measuring systems and methods, and is not limited to practice with only the power system as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many other measurement and/or monitoring applications.
Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
