Abstract:
A deflection measurement probe includes a body portion having a cavity defined by the body portion, a first positional measurement sensor disposed in the cavity of the body portion, the first positional measurement sensor including a sensor tip extending from the body portion operative to contact a measurement surface, and a second positional measurement sensor disposed in the cavity of the body portion, the first positional measurement sensor including a sensor tip extending from the body portion operative to contact a measurement surface.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates to industrial testing systems and particularly to a system for detecting deflection of components of industrial machines. 
         [0002]    Deflection may be defined as the amount a structural component is displaced or deformed under a load. In many industrial machines, such as, for example, large scale generators, components such as ripple springs are compressed during installation. The deflection of the components is measured to ensure that the deflection is within design tolerances. Previous measuring methods included manually measuring the relative positions of a number of points on the component using a hand tool to determine the overall deflection of the component. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    According to one aspect of the invention, a deflection measurement probe includes a body portion having a cavity defined by the body portion, a first positional measurement sensor disposed in the cavity of the body portion, the first positional measurement sensor including a sensor tip extending from the body portion operative to contact a measurement surface, and a second positional measurement sensor disposed in the cavity of the body portion, the first positional measurement sensor including a sensor tip extending from the body portion operative to contact a measurement surface. 
         [0004]    According to another aspect of the invention, a measurement system includes a processor and a measurement probe communicatively connected to the processor, the measurement probe comprising a body portion having a cavity defined by the body portion, a first positional measurement sensor disposed in the cavity of the body portion, the first positional measurement sensor including a sensor tip extending from the body portion operative to contact a measurement surface, and a second positional measurement sensor disposed in the cavity of the body portion, the first positional measurement sensor including a sensor tip extending from the body portion operative to contact a measurement surface. 
         [0005]    According to yet another aspect of the invention, a method for measuring deflection of a surface of an object includes aligning a measurement probe assembly with the surface of the object, disposing an alignment pin of the measurement probe assembly on the surface of the object, applying a force to the measurement probe assembly such that sensor tips of the measurement probe assembly contact the surface of the object, instructing a processor communicatively connected to the measurement probe assembly to measure the position of the sensor tips, and calculating a difference in relative position of the sensor tips. 
         [0006]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0007]    The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0008]      FIG. 1  illustrates a perspective view of an exemplary embodiment of an inspection system. 
           [0009]      FIG. 2  illustrates a perspective view of an illustrated embodiment of a probe assembly. 
           [0010]      FIG. 3  illustrates a top partially cut-away view of the probe assembly. 
           [0011]      FIG. 4  illustrates a perspective view of an example of a sensor of  FIG. 2 . 
           [0012]      FIGS. 5-7  illustrate side views of the operation of the probe assembly of  FIG. 2 . 
           [0013]      FIG. 8  illustrates a block diagram of an exemplary method for measuring the deflection of a component. 
       
    
    
       [0014]    The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0015]      FIG. 1  illustrates a perspective view of an exemplary embodiment of an inspection system  100 . The system includes a processor  102  communicatively connected to a display device  104 , an audio device  105  such as a speaker, an input device  106  that may include, for example, a keyboard, mouse, or other type of input device, and a memory  108 . A probe controller  110  is communicatively connected to the processor  102 , and may include for example, a processor, input and output connections, and a power supply. A probe assembly  112  is communicatively connected to the probe controller  110 . A calibration block  101  includes a flat surface that is operative to mechanically engage the probe assembly  112  during system calibration procedures. Though the illustrated embodiment shows a separate probe controller  110  and processor  102  in alternate exemplary embodiments, the probe controller  110  and the processor  102  may, for example, be included in a single housing unit, or share a single processor. 
         [0016]      FIG. 2  illustrates a perspective view of an illustrated embodiment of a probe assembly  112 . The probe assembly  112  includes a body portion  202  and a plurality of transducers sensors disposed in the body portion  202 . The sensors  204  of the illustrated embodiment are differential variable reluctance transducers (DVRT) however, alternate embodiments may include other types of sensors such as linear variable differential transformers (LVDT). Though the illustrated embodiment includes an arrangement of five DVRTs, alternate embodiments may include any number of DVRTs. The probe assembly  112  includes alignment pins  206  and a connector and cable assembly  208  that is connected to the probe controller  110  (of  FIG. 1 ). 
         [0017]      FIG. 3  illustrates a top partially cut-away view of the probe assembly  112 . In the illustrated embodiment, the sensors  204  are secured in a parallel and coplanar arrangement in an interior cavity of the body portion  202  by fasteners  302  however, alternate embodiments may secure the sensors  204  to the body portion  202  using other means such as, for example, an adhesive or epoxy material, a pinning arrangement or other type of fastening means. The longitudinal axes  301  of the alignment pins  206  are arranged in parallel and coplanar to the longitudinal axes  303  of the sensors  204  in the illustrated embodiment however, in alternate embodiments, the alignment pins  206  may be arranged in a different plane than the sensors  204 . The alignment pins  206  are biased with springs  304  such that a compressive force along the longitudinal axis of the pins  206  will push the pins  206  into the body portion  202 . 
         [0018]      FIG. 4  illustrates a perspective view of an example of a sensor  204 . In the illustrated embodiment the sensor  204  is a DVRT type sensor that includes a sensor portion (coil)  402 , a compressive spring  404 , a spring stop  406 , an end bearing  408  and a nickel titanium core  410  disposed in a tubular body portion  412 . A spherical tip portion  414  is disposed on the distal end of the core  410 . In operation, the position of the core  410  is detected by measuring the differential reluctance of the coil  402  using a sine wave excitation and synchronous demodulator (disposed in the probe controller  110  of  FIG. 1 ) connected to the sensor  204  with a conductive lead  416 . 
         [0019]      FIGS. 5-7  illustrate side views of the operation of the probe assembly  112 . The illustrated embodiment includes a ripple spring  502  (test object), and a wedge  504  (alignment assembly or other surface). In the illustrated embodiment, the wedge  504  is used to secure the ripple spring  502  in position in an electrical machine. The alignment assembly  504  includes alignment pin holes  508  and orifices  506  that allow the probe assembly  112  to be repeatedly aligned in a particular position for repeated measurement tasks. The test object is not limited to ripple springs, and may include any object with a surface that may be tested for deflection. An alignment assembly is useful for repeated measurements; however an alignment assembly is not necessary to perform deflection measurements. 
         [0020]    Referring to  FIG. 6 , in operation, a technician manually aligns the alignment pins  206  with the alignment pin holes  508  and inserts the alignment pins  206  into the alignment pin holes  508 . The alignment pins  206  contact a surface  602  of the ripple spring  502  (test object). A force  601  is applied by the technician on the body portion  202  of the probe assembly  112  that compresses the spring biased alignment pins  206 . 
         [0021]    Referring to  FIG. 7 , the compression of the alignment pins  206  allows the tip portions  414  of the sensors  204  pass through the orifices  506  of the wedge  504  to contact the surface  602  of the ripple spring  502 . The position of each of the tip portions  414  of the sensors  204  is determined by measuring the differential reluctance of the coil  402  (of  FIG. 4 ). The position of each sensor  204  is output by probe controller  110  to the processor  102 . The processor  102  calculates the differences in relative positions of each sensor  204  to determine an overall deflection of the ripple spring  502 . 
         [0022]      FIG. 8  illustrates a block diagram of an exemplary method for measuring the deflection of a ripple springs in an electrical machine similar to the ripple spring  502  (of  FIG. 5 ) using the system  100  (of  FIG. 1 ). Though the illustrated embodiment describes measuring a ripple spring  502  a similar method may be performed to measure the deflection of any material surface. In this regard, in block  802 , the probe  112  is aligned with a test surface of the ripple spring  502 . The probe  112  may be aligned using, for example, an alignment wedge or other alignment means such as a visual indicator or mark on the ripple spring  502 . In block  804 , the alignment pins are placed in contact with the surface of the ripple spring  502 . A force is exerted by a technician on the probe  112  to compress the alignment pins  206  and induce contact between sensors  204  and the ripple spring  502  in block  806 . In block  808 , an instruction is sent to the processor  102  to measure the position of each sensor. The position of each sensor  202  is measured and the deflection of the surface (i.e., difference in relative position of each sensor tip) is calculated in block  810 . In some embodiments, the measurement may be associated with an identifier of the measured ripple spring  502  and saved in the memory  108 . In block  812 , the measurement is compared to a specification threshold value (e.g., less than 20% deflection). If the measurement of deflection is less than the threshold value, an indication that the measurement is satisfactory may be output to a user in block  814 . The output indication of a satisfactory measurement may include, for example, a visual indication on the display device  104  or an associated tone may be output by the audio device  105 . If the measurement is greater than the threshold value, an indication of an unsatisfactory test is output in block  816 , and the ripple spring may be adjusted or replaced and re-measured. 
         [0023]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.