Abstract:
A process is provided involving an agitator. This process includes steps of: (a) disposing an object with the agitator, which object includes an aperture therein; (b) disposing abrasive material within the aperture; and (c) agitating the abrasive material by moving the object using the agitator.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 62/002,464 filed May 23, 2014, which is hereby incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    This disclosure relates generally to surface conditioning and, more particularly, to conditioning an internal surface of an object, for example, to reduce surface roughness of and/or polish the surface. 
         [0004]    2. Background Information 
         [0005]    Various components of a turbine engine may include one or more internal passages; e.g., gas or lubricant passages. A rotor blade airfoil, for example, may include a circuit of internal passages for directing cooling air therewithin to cool the airfoil. Such components are typically formed by casting. Surfaces of a cast component, however, may have a relatively high surface roughness. These rough surfaces may reduce structural integrity of the component and/or turbulate gas flowing through the passages. 
         [0006]    Various surface finishing processes such as machining and media blasting may be performed for reducing surface roughness of exterior surfaces of a component. However, such surface finishing processes cannot be used on interior surfaces of the component where there is no direct line of sight; e.g., surfaces defining internal passages. 
         [0007]    Some specialized processes have been developed for finishing internal surfaces of a component. These processes involve flowing abrasive media through passages of the component. The media may rub against the internal surfaces, thereby grinding away material of the component and partially reducing the surface roughness of the internal surfaces. Such processes, however, may be ineffective for conditioning an internal passage with twists and bends. For example, referring to  FIG. 13 , abrasive media flowing through the passage  1300  of the component  1302  will tend to move towards a radial outer periphery of the passage bend. Therefore, a radial outer portion  1304  of the internal surface defining the passage  100  will receive significantly more surface finishing than the opposing radial inner portion  1306  of the surface. 
         [0008]    There is a need in the art for improved systems and processes for conditioning internal surface(s) of an object such as, for example, a turbine engine component. 
       SUMMARY OF THE DISCLOSURE 
       [0009]    According to an aspect of the invention, a process is provided involving an agitator. This process includes steps of: (a) disposing an object with the agitator, which object includes an aperture therein; (b) disposing abrasive material within the aperture; and (c) agitating the abrasive material by moving the object using the agitator. 
         [0010]    According to another aspect of the invention, a system is provided for conditioning an internal surface of an object, where the internal surface defines at least a portion of an aperture in the object. The system includes a material displacement device adapted to dispose abrasive material into the aperture. The system also includes an agitator adapted to agitate the abrasive material by moving the object. Agitation of the abrasive material may reduce surface roughness of the internal surface. 
         [0011]    The agitator may be adapted to move the object along at least one axis. The agitator may also or alternatively be adapted to move the object about at least one axis. 
         [0012]    The moving may include shaking the object using the agitator. 
         [0013]    The moving may include moving the object relative to a first axis using the agitator. The moving may also include moving the object relative to a second axis using the agitator. The moving may still also include moving the object relative to a third axis using the agitator. 
         [0014]    The object may move back and forth along the first axis. The object may also or alternatively move back and forth about the first axis. 
         [0015]    The abrasive material may be displaced using a material displacement device. The abrasive material may be displaced by a pulse of fluid directed from the material displacement device. The material may be displaced before, after and/or during the moving of the object. 
         [0016]    At least some of the abrasive material may be removed (e.g., purged) from the aperture. Second abrasive material may be disposed into the aperture. The second abrasive material may be agitated by moving the object using the agitator. 
         [0017]    At least a portion of the object, which includes the aperture, may be additive manufactured. 
         [0018]    At least a portion of the object, which includes the aperture, may be cast. 
         [0019]    The aperture may be one of a plurality of apertures in the object. The abrasive material may be disposed in at least one or some or each of the apertures. 
         [0020]    The abrasive material may be or include dry powder media. Alternatively, the abrasive material may be or include a slurry of powder media in a liquid. 
         [0021]    The agitating of the abrasive material may reduce surface roughness of an internal surface of the object, which internal surface defines at least a portion of the aperture. The abrasive material, for example, may polish at least a portion of the internal surface. 
         [0022]    The foregoing features and the operation of the invention will become more apparent in light of the following description and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a side sectional illustration of an object with an internal aperture. 
           [0024]      FIG. 2  is a cross-sectional illustration of the object of  FIG. 1 . 
           [0025]      FIG. 3  is a block diagram of a system for conditioning at least one internal surface of an object. 
           [0026]      FIG. 4  is another side sectional illustration of the object of  FIG. 1  with abrasive material within its internal aperture. 
           [0027]      FIG. 5  is another side sectional illustration of the object of  FIG. 2  with abrasive material within its internal aperture. 
           [0028]      FIG. 6  is a perspective illustration of an agitator. 
           [0029]      FIG. 7  is a perspective cutaway illustration of a fixture for housing an object. 
           [0030]      FIG. 8  is a side sectional illustration of the fixture of  FIG. 7 . 
           [0031]      FIG. 9  is a perspective illustration of another agitator. 
           [0032]      FIG. 10  is a flow diagram of a process involving a conditioning system. 
           [0033]      FIG. 11  is an enlarged view of a portion of the object of  FIG. 5  at point A. 
           [0034]      FIG. 12  is a side cutaway illustration of a geared turbine engine. 
           [0035]      FIG. 13  is cross-sectional illustration of an object with abrasive media flow through an internal passage. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0036]    Various types of objects may be formed with one or more internal apertures; e.g., passages, channels, bores, voids, chambers, etc. One or more of these apertures may be configured to provide fluid flowpath(s) into, out of, within and/or through the object. A ring of a bearing, for example, may include one or more passages for distributing lubricant to roller elements of the bearing. In another example, a rotor blade for a turbine engine may include one or more passages and/or chambers for directing coolant (e.g., air) therewithin to cool an airfoil of the rotor blade. One or more of the apertures (e.g., the passages and/or chambers) may also or alternatively be included to reduce mass and weight of the object (e.g., rotor blade). 
         [0037]    An exemplary object  20  with an internal aperture  22  (e.g., a tortuous and/or serpentine passage) is illustrated in  FIGS. 1 and 2 . This aperture  22  is defined by at least one internal surface  24  of the object  20 . The aperture  22  extends through the object  20  between a first orifice  26  and a second orifice  28 , which orifices  26  and  28  may be disposed on a common side of the object  20 . Of course, in other embodiments, the orifices  26  and  28  may be disposed on different or even opposing sides of the object  20 . 
         [0038]    The object  20  may be formed using one or more manufacturing processes as discussed below in further detail. Subsequent to object  20  formation, at least a portion of the surface  24  may have a relatively large surface roughness. This may be particularly true where the object  20  is formed using additive manufacturing and/or casting. If left unconditioned, such a rough surface may reduce structural integrity of the object  20  and/or turbulate fluid flowing through the aperture  22 . 
         [0039]      FIG. 3  is a block diagram of a system  30  for conditioning at least one internal surface of an object such as the internal surface  24  of  FIGS. 1 and 2 . This conditioning system  30 , for example, may be adapted to reduce the surface roughness of and/or polish the surface  24  using abrasive material. The condition system  30  may also or alternatively prepare (e.g., score) the surface  24  to receive a coating using abrasive material. 
         [0040]    The conditioning system  30  includes a material source  32  (e.g., a hopper or tank), an abrasive material displacement device  34  and an agitator  36 . The conditioning system  30  also includes a controller  38 , which is in signal communication (e.g., hardwired and/or wirelessly connected) with the system components  34  and  36 . 
         [0041]    The material displacement device  34  is fluidly coupled with one or more of the orifices  26  and  28  through one or more fluid conduits  40  and  42 ; e.g., pipes, hoses, channels, troughs, etc. The material displacement device  34  is adapted to direct a quantity of the abrasive material from the material source  32  into the aperture  22  (see  FIGS. 4 and 5 ). The material displacement device  34  may also be adapted to partially displace (e.g., shift, push or siphon) the abrasive material within the aperture  22 . The material displacement device  34  may also or alternatively be adapted to remove (e.g., flush or purge) the abrasive material from the aperture  22 . The removed abrasive material may subsequently be discarded, or returned to the material source  32  for later use. 
         [0042]    The material displacement device  34  may be configured as or include a pump, a hopper screw and/or a conveyor. The material displacement device  34  may also or alternatively be configured as or include a fluid pressure source; e.g., a compressed gas (e.g., air or inert gas) source. In such an embodiment, fluid (e.g., compressed air) may be used to siphon the abrasive material from the material source  32  and direct (e.g., push) the siphon abrasive material into the aperture  22 . The conditioning system  30  of  FIG. 3 , however, is not limited to the exemplary material displacement device configurations described above. 
         [0043]    The agitator  36  is adapted to move (e.g., shake and/or vibrate) the object  20  in order to agitate the abrasive material disposed within the aperture  22  (see  FIGS. 4 and 5 ). The agitator  36 , for example, may be adapted to move (e.g., oscillate) the object  20  back and forth along one or more axes. The agitator  36  may also or alternatively be adapted to move the object  20  back and forth about one or more axes. In addition, the agitator  36  may include a base for supporting the object  20 . The agitator  36 , for example, may be configured as a single axis or multi-axis shaker and/or vibrator. 
         [0044]      FIG. 6  illustrates an exemplary embodiment of the agitator  36 . In this embodiment, the agitator  36  is configured as a multi-axis (e.g., 3-axis) voice coil shaker.  FIG. 6  also illustrates a fixture  44  for securing the object  20  to the agitator  36 . 
         [0045]    Referring to  FIGS. 7 and 8 , the fixture  44  includes a casing  46  (e.g., a sealed or vacuum enclosure) configured to house the object  20  as well as mount to the agitator  36  via, for example, one or more fasteners (see  FIG. 6 ) and/or latches. The fixture  44  may also include one or more inserts  48 - 51  to support the object  20  within the casing  46 ; e.g., cushion and/or firmly hold the object  20  during movement. The inserts may include one or more rigid outer fillers  48  and  49 ; e.g., styrofoam fillers. The inserts may also or alternatively include one or more flexible inner fillers  50  and  51 ; e.g., cushions and/or elastomeric fillers. One or more of the inserts  48 - 51  may be removable such that these insert(s) may be swapped out or removed depending upon the specific object being housed within the casing  46 . Alternatively, one or more of the inserts  48 - 51  may be fixed to the casing  46 . 
         [0046]      FIG. 9  illustrates another exemplary embodiment of the agitator  36 . In this embodiment, the agitator  36  is configured as a single axis shaker; e.g., an x-axis shaker. The fixture  44  (see dashed outline), however, may be mounted to the agitator  36  in a manner that allows the fixture  44  and, thus, the object to be rotated about one or more other axes; e.g., y- and z-axes. The agitator  36 , for example, may include a base  54  and a mount  56 . The mount  56  may be connected to the base  54  by a first axle  58  (e.g., a y-axis axle) or other rotatable joint. The fixture  44  may be connected to the mount by a second axle  60  (e.g., a z-axis axle) or other rotatable joint. In this manner, the fixture  44  may be moved to change the direction the abrasive material is agitated within the aperture  22  (see  FIGS. 4 and 5 ). The conditioning system  30  of  FIG. 3 , of course, is not limited to the exemplary agitator configurations described above and illustrated in  FIGS. 6 and 9 . 
         [0047]    Referring to  FIG. 3 , the controller  38  may be implemented with a combination of hardware and software. The hardware may include memory and at least one processing device, which may include one or more single-core and/or multi-core processors. The hardware may also or alternatively include analog and/or digital circuitry other than that described above. 
         [0048]    The memory is configured to store software (e.g., program instructions) for execution by the processing device, which software execution may control and/or facilitate performance of one or more operations such as those described in the processes below. The memory may be a non-transitory computer readable medium. For example, the memory may be configured as or include a volatile memory and/or a nonvolatile memory. Examples of a volatile memory may include a random access memory (RAM) such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a synchronous dynamic random access memory (SDRAM), a video random access memory (VRAM), etc. Examples of a nonvolatile memory may include a read only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a computer hard drive, etc. 
         [0049]      FIG. 10  is a flow diagram of a process involving a conditioning system such as the system  30  of  FIG. 3 . For ease of description, this process will be described with reference to the object  20  of  FIGS. 1 and 2 . However, the process of  FIG. 10  is not limited to any particular object configurations. 
         [0050]    In step  1000 , the object  20  is disposed with the agitator  36 . For example, referring to  FIGS. 7 and 8 , the object  20  may be packed in the casing  46  and nested between the inserts  48 - 51 . The material displacement device  34  may also be fluidly coupled to the object  20  via the fluid conduits  40  and  42 . The fixture  44  and, more particularly, the casing  46  may subsequently be mounted to the agitator  36  as illustrated in  FIGS. 6 and 9 . 
         [0051]    In step  1002 , a quantity of abrasive material is disposed within the aperture  22 . For example, referring to  FIGS. 3-5 , the controller  38  may signal the material displacement device  34  to direct abrasive material from the material source  32  into the aperture  22  through the first fluid conduit  40 ; e.g., a source conduit. 
         [0052]    The abrasive material may be or include substantially dry powder media. The term “powder” may describe a quantity (e.g., an agglomeration) of discrete particles with substantially uniform or varying sizes; e.g., average diameters. The particle size of one or more of the particles may be between about 001 inches (˜24.5 μm) and about 0.110 inches (˜2800 μm); e.g., between about 0.004 inches (˜106 μm) and about 0.55 inches (˜1400 μm). The process of  FIG. 10 , however, is not limited to any particular abrasive material particle sizes. 
         [0053]    The powder media may be formed from metal and/or non-metal. Examples of suitable metal include, but are not limited to, tungsten carbide, steel grit, iron grit and/or super alloy nickel powder. Examples of suitable non-metal include, but are not limited to, silicon carbide, aluminum oxide, garnet and/or glass bead. The process of  FIG. 10 , however, is not limited to any particular abrasive material materials or forms thereof. For example, in some embodiments, the abrasive material may be configured as a slurry of the powder media mixed within a liquid. Such a slurry may be used where, for example, the abrasive material is to polish the surface  24  opposed to quickly reduce (e.g., cut) relatively high surface roughness. 
         [0054]    In step  1004 , the abrasive material within the aperture  22  is agitated. The controller  38 , for example, may signal the agitator  36  to move (e.g., shake and/or vibrate) the object  20  relative to one or more axes. The agitator  36 , for example, may shake the object  20  back and forth along one or more axes; e.g., x-axis, y-axis and/or z-axis. The agitator  36  may also or alternatively rotate the object  20  back and forth about one or more axes; e.g., x-axis, y-axis and/or z-axis. Such movement, referring to  FIG. 11 , may cause the abrasive material particles to move in various directions within the aperture  22  and rub and/or impinge against the surface  24 . This rubbing and/or impingement may cause the abrasive material particles to cut into the object&#39;s material and thereby reduce surface roughness of and/or polish the surface  24 . 
         [0055]    It is worth noting, the controller  38  may select (i) how the object  20  is moved relative to an axis and/or (ii) which axis or axes the object  20  is moved relative to based upon the specific configuration of the aperture  22 . For example, the controller  38  may signal the agitator  36  to move the object  20  relative to each axis in order to condition each portion (e.g., inner, outer and side portions) of the surface at the bend illustrated in  FIG. 11 . In another example, where the aperture  22  extends straight through the object  20  along the x-axis (not shown), the controller  38  may signal the agitator  36  to move back and forth along the y-axis and/or the z-axis. The controller  38  may also signal the agitator  36  to rotate back and forth about the x-axis. In this manner, the object  20  movement will cause the abrasive material particles to impinge against the surface  24  without causing the particles to move out of the aperture  22 . A similar technique may also be used to target specific portions of the surface  24 ; e.g., portions defining a curve or twist in the aperture  22 . 
         [0056]    The movement along and/or about the different axes may be performed sequentially. For example, the object  20  may be moved back and forth about the x-axis before the y-axis. Alternatively, the movement along and/or about the different axes may be performed substantially contemporaneously or overlap. For example, the object  20  may be moved back and forth along all three axes at the same time. 
         [0057]    In step  1006 , at least some of the abrasive material is removed (e.g., purged) from the aperture  22 . The controller  38 , for example, may signal the material displacement device  34  to direct a pulse or stream of purge fluid (e.g., compressed gas or liquid) into the aperture  22  through the first fluid conduit  40 . This purge fluid may push some or substantially all of the abrasive material out of the aperture  22  and into the second fluid conduit  42 ; e.g., a return conduit. Depending upon the state of the purged abrasive material, this material may subsequently be discarded or returned to the material source  32  for later use. 
         [0058]    In step  1008 , the steps  1002 ,  1004  and  1006  may be repeated with new abrasive material to further reduce the surface roughness of and/or polish the surface  24 . The new abrasive material may be the same type of abrasive material as was disposed in the step  1002 . Alternatively, the new abrasive material may be different than the abrasive material of the step  1002 . For example, the new abrasive material may be composed from different material and/or have different particle sizes. The new material may also or alternatively be provided in a different form. The abrasive material provided in the step  1002 , for example, may be dry powder media selected to quickly reduce surface roughness. The new abrasive material, on the other hand, may be a slurry of powder media in a liquid tailored for (e.g., fine) polishing of the surface  24 . In still another example, the liquid content in the abrasive material may be changed between repetitions of the step  1002 . 
         [0059]    It is worth noting, the step  1008  may be repeated as may times as necessary in order to condition the surface  24 . The step  1008  may also be omitted when the surface  24  is conditioned to specification during the step  1004 . 
         [0060]    In some embodiments, the process of  FIG. 10  may include a step of forming the object  20 . The object  20  may be formed using one or more manufacturing processes which include, but are not limited to, additive manufacturing, casting, milling, forging and machining. The term “additive manufacturing” may describe a process where an additive manufacturing system builds up a part or parts in a layer-by-layer fashion. For example, for each layer, the additive manufacturing system may spread and compact a layer of additive manufacturing material (e.g., metal powder and/or non-metal powder) and solidify one or more portions of this material layer with an energy beam; e.g., a laser beam or an electron beam. Examples of an additive manufacturing system include, but are not limited to, a laser sintering system, an electron beam system, a laser powder deposition system and an EB wire deposition system. Examples of metal(s) from which the object  20  may be formed include, but are not limited to, nickel (Ni), titanium (Ti), steel, stainless steel, cobalt (Co), chromium (Cr), tungsten (W), molybdenum (Mo) and/or alloys including one or more of the foregoing metals such as Waspaloy, Stellite, Aluminum, etc. The object  20 , however, is not limited to being formed from the foregoing materials. 
         [0061]    In some embodiments, the process of  FIG. 10  may include a step of displacing the abrasive material within the aperture  22 . The controller  38 , for example, may signal the material displacement device  34  to slightly displace (e.g., push and/or pull) the abrasive material along a centerline of the aperture  22 . The abrasive material may be displaced, for example, by pulsing fluid (e.g., compressed gas or liquid) into the aperture  22  through the first fluid conduit  40 . This displacement may be repeated for one or more iterations, thereby causing the abrasive material to rub against and cut into the surface  24 . This rubbing may further aid in reducing the surface roughness of and/or polishing the surface  24 . 
         [0062]    The abrasive material may be displaced one or more times while the object  20  is being moved by the agitator  36 . The abrasive material may also or alternatively be displaced one or more times before, after and/or during pauses between movements of the object  20  with the agitator  36 . 
         [0063]    In some embodiments, where the object  20  includes a plurality of apertures  22 , the material displacement device  34  may be fluidly coupled to a select one or few of these apertures  22 . In this manner, the surfaces  24  defining those respective apertures  22  are at least partially conditioned. Alternatively, the material displacement device  34  may be fluidly coupled to each of the apertures  22 , sequentially or contemporaneously, to condition at least a portion of each surface  24 . 
         [0064]    In some embodiments, the fixture  44  may be configured to receive and house a plurality of objects  20 . In this manner, the conditioning system  30  may collectively condition surfaces of the objects  20 , which may reduce manufacturing time and/or costs. 
         [0065]    The object(s)  20  conditioned by the conditioning system  30  may have various configurations and may be included in various types of apparatuses and systems. The object  20 , for example, may be configured as a bearing race or a rotor blade of a turbine engine.  FIG. 12  illustrates an exemplary embodiment of such a turbine engine  94 ; e.g., a geared turbofan engine. 
         [0066]    The turbine engine  94  of  FIG. 12  extends along an axial centerline  96  between an upstream airflow inlet  98  and a downstream airflow exhaust  100 . The turbine engine  94  includes a fan section  102 , a compressor section  103 , a combustor section  104  and a turbine section  105 . The compressor section  103  includes a low pressure compressor (LPC) section  103 A and a high pressure compressor (HPC) section  103 B. The turbine section  105  includes a high pressure turbine (HPT) section  105 A and a low pressure turbine (LPT) section  105 B. The engine sections  102 - 105  are arranged sequentially along the centerline  96  within a housing  106 . 
         [0067]    Each of the engine sections  102 - 103 B,  105 A and  105 B includes a respective rotor  108 - 112 . Each of these rotors  108 - 112  includes a plurality of rotor blades arranged circumferentially around and connected to one or more respective rotor disks. The rotor blades, for example, may be formed integral with or mechanically fastened, welded, brazed, adhered and/or otherwise attached to the respective rotor disk(s). 
         [0068]    The fan rotor  108  is connected to a gear train  114 , for example, through a fan shaft  116 . The gear train  114  and the LPC rotor  109  are connected to and driven by the LPT rotor  112  through a low speed shaft  117 . The HPC rotor  110  is connected to and driven by the HPT rotor  111  through a high speed shaft  118 . The shafts  116 - 118  are rotatably supported by a plurality of bearings  120 ; e.g., rolling element and/or thrust bearings. Each of these bearings  120  is connected to the engine housing  106  by at least one stationary structure such as, for example, an annular support strut. 
         [0069]    During operation, air enters the turbine engine  94  through the airflow inlet  98 , and is directed through the fan section  102  and into a core gas path  122  and a bypass gas path  124 . The air within the core gas path  122  may be referred to as “core air”. The air within the bypass gas path  124  may be referred to as “bypass air”. The core air is directed through the engine sections  103 - 105  and exits the turbine engine  94  through the airflow exhaust  100  to provide forward engine thrust. Within the combustor section  104 , fuel is injected into a combustion chamber and mixed with the core air. This fuel-core air mixture is ignited to power the turbine engine  94 . The bypass air is directed through the bypass gas path  124  and out of the turbine engine  94  through a bypass nozzle  126  to provide additional forward engine thrust. Alternatively, at least some of the bypass air may be directed out of the turbine engine  94  through a thrust reverser to provide reverse engine thrust. 
         [0070]    The object  20  may be included in various turbine engines other than the one described above. The object  20 , for example, may be included in a geared turbine engine where a gear train connects one or more shafts to one or more rotors in a fan section, a compressor section and/or any other engine section. Alternatively, the object  20  may be included in a turbine engine configured without a gear train. The object  20  may be included in a geared or non-geared turbine engine configured with a single spool, with two spools (e.g., see  FIG. 12 ), or with more than two spools. The turbine engine may be configured as a turbofan engine, a turbojet engine, a propfan engine, or any other type of turbine engine. The present invention therefore is not limited to any particular turbine engine types or configurations. Furthermore, while the object  20  is described above as being included in a turbine engine, the object  20  may also be configured with various non-turbine engine systems; e.g., HVAC systems, automobile systems, etc. 
         [0071]    While various embodiments of the present invention have been disclosed, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. For example, the present invention as described herein includes several aspects and embodiments that include particular features. Although these features may be described individually, it is within the scope of the present invention that some or all of these features may be combined with any one of the aspects and remain within the scope of the invention. Accordingly, the present invention is not to be restricted except in light of the attached claims and their equivalents.