Referring to the figures, an exemplary optical subsystem 2 is illustrated having multiple components for inspecting and determining flaws on surfaces, such as cracks, for example, in a threaded bore. In one embodiment, components of the optical subsystem 2 may include a laser or incoherent light source 8 and a surface inspection device 4. A beam splitter assembly 6 may be coupled between the surface inspection device 4 and the laser or incoherent light source 8. In one disclosed embodiment, a fiber optic cable 17A may be utilized to couple the beam splitter assembly 6 to the incoherent light source 8. Likewise, another fiber optic cable 17B may be utilized to couple the beam splitter assembly 6 to the surface inspection device 4. The surface inspection device 4 may include a rotary optical joint 20 which may be configured to connect with one end of the fiber optic cable 17B. Another fiber optic cable 17C may be connected from the rotary optical joint 20 to a probing device 15. The rotary optical joint 20 may facilitate infinite rotation of the fiber optic cable 17C connected to the probing device 15. Other cables or connectors suitable for transferring laser or incoherent light may be utilized to couple the beam splitter assembly 6 to the surface inspection device 4 and the laser or incoherent light source 8.
Hence, the laser or incoherent light source 8 may supply a laser or incoherent light beam to the beam splitter assembly 6. At least a portion of the laser or incoherent light may pass through the beam splitter assembly 6 and enter the surface inspection device 4, such as via the rotary optical joint 20, and be supplied to the probing device 15. The probing device 15 may be configured to receive the laser or incoherent light and deflect the laser or incoherent light as an optical beam 23 onto a surface of an object.
For example,
The probing device 15 may also include a prism 7. The telescope may direct the laser or incoherent light 11 onto the prism 7. The prism 7 may redirect the laser or incoherent light 11 to a prescribed location point. In the disclosed embodiment, the prism 7 may include a 90° turning prism which may receive and redirect the laser or incoherent light 11, for example, at 90° from a longitudinal axis of the probing device 15. The redirected laser or incoherent light 11 may be projected through a window 9 of the probing device 15 as an optical beam 23. The window 9 may also prevent foreign articles, such as dust, from entering the probing device 15. The optical beam 23 may be focused to a point having a prescribed size and location such as in the root 33 of one or more threads 27. Hence, the aforementioned size may include a spot having a dimension which may fall within the dimension of one or more threads 27.
Once an amount of laser or incoherent light is projected, for example, as an optical beam 23 onto a surface of an object, an amount of reflected light may be received back into the probing device 15. The prism 7 may redirect the reflected light back towards the telescope. The telescope may facilitate alignment of the reflected light back into the fiber optic cable 17C. Hence, turning, again, to
Turning to
A probe 26 may be used to facilitate identification of one or more flaws, such as fatigue cracks on internal surfaces of a threaded bore. Probe 26 of tool 10 may correspond to the probing device 15 of the surface inspection device 4. Moreover, the probe 26 may function in the same capacity as the probing device 15 of the surface inspection device 4. Hence, the probe 26 may be configured to receive laser or incoherent light emitted from a laser or incoherent light source 8 (e.g.,
Turning to
The threads 54 of the split housing assembly 56 may extend through an opening 31 of the upper housing assembly 30. The threads 54 may also be inserted through a ball bearing assembly 64, a spacer 66, a ball bearing assembly 65, and an opening 35 of the handle mount plate 34. Again, bearing lock nut 38 may be threaded upon corresponding threads 54 of the split housing assembly 56. Appropriate tightening of the bearing lock nut 38 may retain the handle mount plate 34, the upper housing assembly 30, and the components on the shaft 12 together in a secure arrangement. As shown in
Returning to
The disclosed surface inspection device 4 may have applicability in any system, for example, requiring inspection and detection of flaws on surface structures. These surface structures may include cracks, for example, in the internal surface of a threaded bore. In operation, laser or incoherent light from the laser or incoherent light source 8 may be provided to the probing device 15 of the surface inspection device 4. The probing device 15 may emit the laser or incoherent light as an optical beam 23 focused to a point, for example, onto a surface of an object. In one disclosed embodiment, the optical beam 23 is emitted at approximately 90 degrees from a surface of the probing device 15 onto a surface of the object. The aforementioned surface of the object may include threads 27 of a threaded bore 25.
In order to increase the probability of detecting existing flaws on the surface of threads 27, it is desirable to project the optical beam 23 directly into the root 33 of the threads 27. This may require making an adjustment of the optical beam 23 with respect to the threads 27. Hence, it may be necessary to adjust a position of the probing device 15 to accurately align the optical beam 23 in the root 33 of the threads 27.
In one disclosed embodiment, the surface inspection device 4 may include a CNC machine. The CNC machine may manipulate a position of the probing device 15 to be adjusted in directions, for example, along the X-axis, Y-axis, and Z-axis. Hence, a position of the probing device 15 may be adjusted along a vertical axis of the interior 37 of the threaded bore 25. This may include aligning the optical beam 23 emitted from the probing device 15 with the root 33 of the threads 27 of the threaded bore 25. Moreover, the optical beam 23 may be swept along the threads in a rotary fashion by rotating the probing device 15 via the CNC machine such as along the Z-axis.
As previously discussed, the probing device 15 may also be configured to receive a reflectance of the optical beam 23 such as from the surface of the interior 37 of the threaded bore 25. The reflected optical beam 23 may be transmitted from the probing device 15 back to the beam splitter assembly 6. A photodetector 19 (e.g., coupled to the beam splitter assembly 6) may receive at least a portion of the reflected optical beam 23. The photodetector 19 may measure the power of the reflected optical beam 23. The measured power may be converted to an electrical output signal 21. The electrical output signal 21 may be quantified in a measurement, such as voltage, and further analyzed. In one embodiment, a surface flaw may be indicated by a change in magnitude of reflected energy (which may also translate into one or more voltage measurements). The voltage measurements may be used in comparison with other voltage measurements. A measured voltage range may be analyzed in terms of a change in magnitude of reflected energy, for example, over a period of time. These voltage ranges may be measured, for example, across portions of the interior 37. An irregular surface, such as a surface flaw indicated by a crack, may scatter the projected optical beam 23. The result of which may include less laser or incoherent light returning to the probing device 15 and, hence, less power measured by the photodetector 19. Thus, by analyzing measured voltage ranges corresponding to the measured power of the reflected optical beam 23, it may be possible to ascertain the presence and location of surface flaws, such as cracks located within the threaded bore 25.
In another disclosed embodiment, the surface inspection device 4 may, alternatively, include the disclosed tool 10. As previously discussed, laser or incoherent light from the laser or incoherent light source 8 may be provided to the probe 26 of tool 10. Again, the probe 26 may function in the same capacity as the probing device 15. This may include emitting the laser or incoherent light as an optical beam 23 onto a surface of an object. In one disclosed embodiment, the optical beam 23 is emitted at approximately 90° from a surface of the probe 26 onto a surface of the object. The aforementioned surface of the object may include threads 27 of a threaded bore 25.
As in the previous embodiment, it is desirable to project the optical beam 23 directly into the root 33 of the threads 27 in order to increase the probability of detecting existing flaws on the surface of threads 27. This may require making an adjustment of the optical beam 23 with respect to the threads 27. Hence, it may be necessary to adjust a position of the probe 26 to align the optical beam 23 in the root 33 of the threads 27.
The probe end of the shaft 12 may be oriented to insert the probe 26 into a threaded bore 25 of a component. The threads 14 of tool 10 may be aligned with internal mating threads 27 of the bore 25. The drive unit 18 may be enabled to drive the shaft 12 to rotate the threads 14 into engagement with the mating internal threads 27 of the bore 25. As the threads 14 engage the internal threads 27 of the bore 25, the probe 26 may traverse a length of the bore. The aforementioned threaded engagement may facilitate alignment of the probe 26 for emitting laser or incoherent light as an optical beam 23 along targeted areas. This may ensure that the optical beam 23 covers all targeted areas for detecting potential flaws, such as in the root 33 of the threads 27.
The turning motion of the shaft 12 may guide the probe 26 down the threaded bore 25. The optical beam 23 emitted from the probe 26 (e.g., 90° from the side of the probe 26) may sweep down the bore 25 including a portion having internal threads 27. For example, the optical beam 23 may be swept down the root 33 of one or more internal threads 27 to inspect them for damage. As the optical beam 23 sweeps across an interior 37 surface of the threaded bore 25, an amount of laser or incoherent light may be reflected from an internal surface (e.g., the root 33 of internal threads 27) of the bore 25. The probe 26 may be configured to receive a reflectance of the optical beam 23 such as from the surface of the interior 37 of the threaded bore 25. In one disclosed embodiment, the reflected optical beam 23 may be transmitted from the probe 26 back to the beam splitter assembly 6. A photodetector 19 (e.g., coupled to the beam splitter assembly 6) may receive at least a portion of the reflected optical beam 23. The photodetector 19 may measure the power of the reflected optical beam 23. The measured power may be converted to an electrical output signal 21. The electrical output signal 21 may be quantified in a measurement, such as voltage, and further analyzed. Again, by analyzing measured voltage ranges corresponding to the measured power of the reflected optical beam 23, it may be possible to ascertain the presence and location of surface flaws, such as cracks located within the threaded bore 25.
As the probe 26 is inserted within the threaded bore 25, a top surface of the bore may come into contact with the lower spring pad 24. Continued rotation of the threads 14 into the threaded bore 25 may cause compression of the spring 22. Hence, an axial force may be generated along a length of the shaft 12 to produce a tight threaded engagement between the external threads 14 and the internal threads 27 of the bore. This may reduce any “play” or loose fit between mutual threads. The disclosed tight threaded engagement may facilitate alignment of the probe 26 within the bore 25 for performing inspection of the root 33 of the threads 27 and detecting any flaws. The disclosed axial tension may maintain the mutual threads in a consistent engagement so that the probe 26 can more accurately aim and maintain laser or incoherent light at a specific location, including, for example, the root 33 of a thread 27. Maintaining the mutual threads in the disclosed consistent engagement may also allow the probe 26 to more accurately receive a reflected amount of laser or incoherent light, such as, from an interior 37 surface of the bore 25.
It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed apparatus and method without departing from the scope of the disclosure. For example, additional or alternative structure may be provided to position the probe 26 relative to the threads 27 of the bore 25. This may include defining the threads 14 of shaft 12 to include any structure, such as a thread engagement member, that may be configured to physically contact the threads 27 of bore 25 in order to maintain a position of the probe 26. Hence, in one example, the tool 10 may include ball bearings configured to mate with the threads 27 of bore 25. In another example, the tool 10 may include one or more radially expandable devices received within threads 27 of bore 25 to maintain a position of the probe 26. Additionally, other embodiments of the apparatus and method will be apparent to those skilled in the art from consideration of the specification. For example, some described embodiments may be useful for inspecting additional surface structures of the bore 25 including, for example, interior regions 37 having non-threaded surfaces. In an embodiment wherein the surface inspection device 4 includes a CNC machine, the CNC machine may manipulate a position of the probing device 15 to be adjusted in directions, for example, along the X-axis, Y-axis, and Z-axis. Hence, in one disclosed embodiment, a position of the probing device 15 may be adjusted along a vertical axis of the interior 37 of the non-threaded portion of the bore 25. This may include sweeping the optical beam 23 emitted from the probing device 15 over the aforementioned non-threaded portion of the bore 25. The sweeping motion may include rotating the probing device 15 via the CNC machine such as along the Z-axis. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.