Patent Publication Number: US-11022145-B2

Title: Bushing arranged between a body and a shaft, and connected to the shaft

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and is a divisional of U.S. patent application Ser. No. 14/107,719 filed Dec. 16, 2013, which claims priority to U.S. Provisional Appln. No. 61/765,439 filed Feb. 15, 2013. The &#39;719 and &#39;439 applications are hereby incorporated herein by reference in their entireties. 
    
    
     This invention was made with government support under Contract No. N00019-02-C-3003 awarded by the United States Navy. The government may have certain rights in the invention. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This disclosure relates generally to bushings and, more particularly, to a bushing that reduces wear between a shaft and a body of, for example, a variable area vane arrangement for a turbine engine. 
     2. Background Information 
     A typical turbine engine includes a plurality of engine sections such as, for example, a fan section, a compressor section, a combustor section and a turbine section. The turbine engine may also include a variable area vane arrangement. Such a vane arrangement may be configured to guide and/or adjust the flow of gas through a respective one of the engine sections. Alternatively, the vane arrangement may be configured to guide and/or adjust the flow of gas between adjacent engine sections. 
     A typical variable area vane arrangement includes a plurality of adjustable stator vanes. Each of the stator vanes includes an airfoil that extends between an outer vane platform and an inner vane platform. Each of the stator vanes also includes an outer shaft and an inner shaft. The outer shaft is rotatably connected to the outer vane platform. The inner shaft is rotatably connected to the inner vane platform. A floating inner bushing may be arranged between the inner shaft and the inner vane platform. A floating outer bushing may be arranged between the outer shaft and the outer vane platform. Such floating bushings may rub against and therefore wear both the shafts and vane platforms. 
     SUMMARY OF THE DISCLOSURE 
     According to an aspect of the invention, a variable area vane arrangement is provided that includes a stator vane, a bushing, and a vane platform with an aperture. The stator vane rotates about an axis, and includes a shaft that extends along the axis into the aperture. The bushing is connected to the shaft, and arranged within the aperture between the vane platform and the shaft. 
     According to another aspect of the invention, another variable area vane arrangement is provided that includes a stator vane, a bushing, and a vane platform with an aperture. The stator vane rotates about an axis, and includes a shaft that extends along the axis into the aperture. The bushing is connected to the shaft, and separates the vane platform from the shaft. 
     According to still another aspect of the invention, a turbine engine is provided that includes a shaft, a bushing, and a turbine engine body with an aperture. The shaft rotates about an axis, and extends along the axis into the aperture. The bushing is connected to the shaft, and arranged within the aperture between the body and the shaft. 
     The bushing may be press fit onto the shaft. 
     The bushing may be mechanically fastened to the shaft. For example, an anti-rotation element may connect the bushing to the shaft. The bushing may include an inner flange that engages a distal end of the shaft. The anti-rotation element may be a fastener that (e.g., fixedly) connects the flange to the shaft. 
     The bushing may be bonded (e.g., welded, brazed or otherwise adhered) to the shaft. 
     The bushing may include a coated outer bearing surface that engages the vane platform. 
     A second bushing may be arranged within the aperture between the vane platform and the bushing. This second bushing may be (e.g., fixedly) connected to the vane platform. 
     The vane platform may extend circumferentially around a second axis. The shaft may extend into the aperture in a radial inward direction relative to the second axis. 
     The vane platform and a second vane platform may form a gas path. The stator vane may include an airfoil that rotates about the axis within the gas path. 
     The aperture may be one of a plurality of apertures included in the vane platform. The stator vane may be one of a plurality of stator vanes. Each of the stator vanes may include a shaft that rotates about a respective axis, and extends into a respective one of the apertures along the respective axis. The bushing may be one of a plurality of bushings that are respectively arranged within the apertures between the vane platform and the respective shafts. Each of the bushings may be connected to a respective one of the shafts. 
     A plurality of engine sections may be included that are arranged along a second axis. The engine sections may include a compressor section, a combustor section and/or a turbine section. A variable area vane arrangement may be included that directs gas (e.g., into or through) for one of the engine sections. The vane arrangement may include a vane platform, a stator vane and the bushing. The vane platform may include the body, and the stator vane may include the shaft. The engine sections may also include a fan section, where the vane arrangement directs gas for the fan section. A gear train may be included that connects a rotor in a first of the engine sections to a rotor in a second of the engine sections. 
     According to an aspect of the invention, a variable area vane arrangement is provided that includes a vane platform, a stator vane, and a bushing that is fixedly connected to the vane platform. The vane platform includes an aperture having a depth that extends along an axis. The stator vane rotates about the axis, and includes a shaft that extends along the axis into the aperture. The bushing is arranged within the aperture between the vane platform and the shaft. The bushing has a length that extends along the axis and is substantially equal to or less than the depth. 
     According to another aspect of the invention, another variable area vane arrangement is provided that includes a vane platform, a stator vane, and a bushing. The vane platform includes an aperture having a depth that extends along an axis. The stator vane rotates about the axis, and includes a shaft that extends along the axis into the aperture. The bushing is arranged within the aperture between the vane platform and the shaft, and is axially retained and rotatably constrained within the aperture. The bushing has a length that extends along the axis and is substantially equal to or less than the depth. 
     According to still another aspect of the invention, a turbine engine is provided that includes a turbine engine body, a shaft, and a bushing that is fixedly connected to the body. The body includes an aperture having a depth that extends along an axis into the body. The shaft rotates about the axis, and extends along the axis into the aperture. The bushing is arranged within the aperture between the body and the shaft. The bushing has a length that extends along the axis and is substantially equal to or less than the depth. 
     The aperture may extend into the vane platform from a (e.g., inner or outer) platform side. The bushing may be recessed into the vane platform from the platform side by a distance along the axis. 
     The aperture may extend within the vane platform to a shelf. The bushing may extend along the axis between opposing bushing ends. A first of the bushing ends may engage the shelf. 
     The bushing may be press fit into the vane platform. The bushing may also or alternatively be bonded to the vane platform. The bushing may also or alternatively be mechanically fastened to the vane platform. For example, an element such as a fastener, key, protrusion, compression sleeve, ring, etc. may axially retain and/or rotatably constrain the bushing within the aperture. 
     A second aperture may extend (e.g., radially or axially) into the vane platform from the aperture. The bushing may include a sleeve. The element may extend into the second aperture from the sleeve. 
     The vane platform may include a first platform segment with a first mate face, and a second platform segment with a second mate face that engages (e.g., contacts) the first mate face. The aperture may extend into the first and the second platform segments. The element may extend into the first and/or the second platform segments. For example, at least a portion of the second aperture may extend into the first platform segment from the first mate face. 
     The second aperture and/or the element may each have an arcuate (e.g., crescent, semi-annular, etc.) cross-sectional geometry. Alternatively, the second aperture and/or the element may each have a polygonal (e.g., square, rectangular, triangular, etc.) cross-sectional geometry. 
     The element may include a compression sleeve (e.g., an elastic polymer sleeve) arranged within the aperture between the vane platform and the bushing. 
     The element may include a fastener (e.g., a pin, bolt, etc.) that extends from the vane platform into the bushing. 
     The element may include an annular ring that extends into the vane platform and the bushing. 
     A second bushing may be arranged within the aperture between the bushing and the shaft. The second bushing may be connected to the shaft. 
     The vane platform may extend circumferentially around a second axis. The shaft may extend into the aperture in a radial inwards or outwards direction relative to the second axis. 
     A plurality of engine sections may be included that are arranged along a second axis. The engine sections may include a compressor section, a combustor section and a turbine section. A variable area vane arrangement may be included that directs gas for (e.g., into or through) one of the engine sections. The vane arrangement may include a vane platform, a stator vane and the bushing. The vane platform may include the body, and the stator vane may include the shaft. The engine sections may also include a fan section, where the variable area vane arrangement directs gas for the fan section. A gear train may be included that connects a rotor in a first of the engine sections to a rotor in a second of the engine sections. 
     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 
         FIG. 1  is a side cutaway illustration of a turbine engine; 
         FIG. 2  is a partial, side sectional illustration of a variable area vane arrangement; 
         FIG. 3  is a partial illustration of an outer side of an inner vane platform for the vane arrangement of  FIG. 2 ; 
         FIG. 4  is a partial illustration of an outer side of an outer vane platform for the vane arrangement of  FIG. 2 ; 
         FIG. 5  is a partial, sectional illustration of an alternate variable area vane arrangement; 
         FIG. 6  is a partial, sectional illustration of another alternate variable area vane arrangement; 
         FIG. 7  is a partial, sectional illustration of a bushing arranged within an aperture of a vane platform; 
         FIG. 8  is a perspective, sectional illustration of the aperture and vane platform of  FIG. 7 ; 
         FIG. 9  is a perspective illustration of the bushing of  FIG. 7 ; 
         FIG. 10  is a partial, perspective illustration of an alternate bushing arranged within an aperture of an axial platform segment; 
         FIG. 11  is a perspective illustration of the aperture and platform segment of  FIG. 10 ; 
         FIG. 12  is a partial, perspective illustration of another alternate bushing arranged within an aperture of an axial platform segment; 
         FIG. 13  is a partial, perspective illustration of another alternate bushing arranged within an aperture of an axial platform segment; 
         FIG. 14  is a partial, perspective illustration of another alternate bushing arranged within an aperture of an axial platform segment; 
         FIG. 15  is a partial, sectional illustration of another alternate variable area vane arrangement; 
         FIG. 16  is a partial, perspective illustration of another alternate bushing arranged within an aperture of an axial platform segment; 
         FIG. 17  is a partial, sectional illustration of another alternate variable area vane arrangement; and 
         FIG. 18  is a side cutaway illustration of an alternate turbine engine. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a side cutaway illustration of a turbine engine  20  that extends along a first axis  22  between a forward airflow inlet  24  and an aft airflow exhaust  26 . The engine  20  includes a fan section  28 , a compressor section  29 , a combustor section  30 , a turbine section  31  and a nozzle section  32 . These engine sections  28 - 32  are arranged sequentially along the first axis  22  and housed within an engine case  34 . 
     The engine  20  also includes at least one variable area vane arrangement  36  for directing gas for one of the engine sections  28 - 32 ; e.g., guiding and/or adjusting flow of air into (or through) the fan section  28 . Referring to  FIG. 2 , the variable area vane arrangement  36  includes an inner vane platform  38 , an outer vane platform  40 , one or more adjustable stator vanes  42 , and one or more bushings; e.g., inner bushings  44  and outer bushings  46 . In one embodiment, the vane platforms  38  and  40  may be annular. In addition, the variable area vane arrangement  36  may also include one or more fixed stator vanes (not shown). 
     Referring to  FIG. 1 , the inner vane platform  38  extends circumferentially around the first axis  22 . Referring now to  FIGS. 2 and 3 , the inner vane platform  38  extends axially, relative to the first axis  22 , between a forward platform end  48  and an aft platform end  50 . The inner vane platform  38  extends radially, relative to the first axis  22 , between an inner platform side  52  and an outer platform side  54 . The inner vane platform  38  includes one or more apertures  56 , which are circumferentially arranged about the first axis  22 . Each of the apertures  56  extends along a respective second axis  58  at least partially into the inner vane platform  38 , which defines an aperture depth  60 . For example, each of the apertures  56  extends radially inward, relative to the first axis  22 , into the inner vane platform  38  from the outer platform side  54  to a (e.g., annular) shoulder  62 . A vent  64  or any other type of aperture may extend through the inner vane platform  38  from the aperture  56  and shoulder  62  to the inner platform side  52 . 
     The inner vane platform  38  may also include a plurality of discrete (e.g., annular) axial platform segments  66  and  68 . The first platform segment  66  extends axially, relative to the first axis  22 , from the forward platform end  48  to a first mate face  70 . The second platform segment  68  extends axially, relative to the first axis  22 , from the aft platform end  50  to a second mate face  72 . The first platform segment  66  is connected to the second platform segment  68 , and the first mate face  70  engages (e.g., contacts) the second mate face  72 . Each of the apertures  56  may extend into both the first and the second platform segments  66  and  68 . The first platform segment  66 , for example, includes forward portions  74  of the apertures  56  and the second platform segment  68  includes aft portions  76  of the apertures  56 . 
     Referring to  FIG. 1 , the outer vane platform  40  extends circumferentially around the first axis  22 . Referring now to  FIGS. 2 and 4 , the outer vane platform  40  extends axially, relative to the first axis  22 , between a forward platform end  78  and an aft platform end  80 . The outer vane platform  40  extends radially, relative to the first axis  22 , between an inner platform side  82  and an outer platform side  84 . The outer vane platform  40  includes one or more apertures  86  that are circumferentially arranged about the first axis  22 . Each of the apertures  86  may extend along the respective second axis  58  at least partially into the outer vane platform  40 , which defines an aperture depth  88 . For example, each of the apertures  86  extends radially, relative to the first axis  22 , through the outer vane platform  40  between the inner and the outer platform sides  82  and  84 . 
     The outer vane platform  40  may also include a plurality of discrete (e.g., annular) axial platform segments  90  and  92 . The first platform segment  90  extends axially, relative to the first axis  22 , from the forward platform end  78  to a first mate face  94 . The second platform segment  92  extends axially, relative to the first axis  22 , from the aft platform end  80  to a second mate face  96 . The first platform segment  90  is connected to the second platform segment  92 , and the first mate face  94  engages the second mate face  96 . Each of the apertures  86  may extend into both the first and the second platform segments  90  and  92 . The first platform segment  90 , for example, includes forward portions  98  of the apertures  86  and the second platform segment  92  includes aft portions  100  of the apertures  86 . 
     Referring to  FIG. 2 , each of the adjustable stator vanes  42  includes an airfoil  102  and one or more shafts; e.g., an inner shaft  104  and an outer shaft  106 . The airfoil  102  extends radially, relative to the first axis  22 , between an inner airfoil end  108  and an outer airfoil end  110 . The inner shaft  104  extends along the respective second axis  58  from the inner airfoil end  108  to an inner vane end  112 . The outer shaft  106  extends along the respective second axis  58  from the outer airfoil end  110  to an outer vane end  114 . 
     Each of the inner bushings  44  and/or the outer bushings  46  may be configured as an annular sleeve, and extend circumferentially around the respective second axis  58 . One or more of the inner bushings  44  each extends axially, relative to the respective second axis  58 , between opposing bushing ends  116  and  118 , which defines a bushing length  120 . This bushing length  120  may be less than (or substantially equal to or greater than) the aperture depth  60 . One or more of the outer bushings  46  each extends axially, relative to the respective second axis  58 , between opposing bushing ends  122  and  124 , which defines a bushing length  126 . This bushing length  126  may be substantially equal to (or less or greater than) the aperture depth  88 . One or more of the inner and/or outer bushings  44  and  46  may have a unitary body, or alternatively may be configured as a split bushing. One or more of the inner and/or outer bushings  44  and  46  may be constructed from materials such as metal, polymer, etc. 
     Referring to  FIG. 1 , the inner vane platform  38  is arranged radially within the outer vane platform  40 , which forms a (e.g., annular) gas path  128  therebetween. The adjustable stator vanes  42  are arranged circumferentially around the first axis  22 , and rotatably connected to the inner and/or the outer vane platforms  38  and  40 . Referring to  FIG. 2 , each airfoil  102  extends through the gas path  128 . The inner airfoil end  108  is located adjacent the outer platform side  54 , and the outer airfoil end  110  is located adjacent the inner platform side  82 . Each inner shaft  104  extends into the respective aperture  56 . Each outer shaft  106  extends through the respective aperture  86 , and may be connected to a control arm  130  at (e.g., adjacent, proximate or on) the outer vane end  114 . Each inner bushing  44  is arranged within the respective aperture  56  between the inner vane platform  38  and the respective inner shaft  104 . The inner bushing end  116  is located adjacent and may engage the respective shelf  62 . The outer bushing end  118  may be recessed from (or flush with) the outer platform side  54  by a distance along the axis  58 . Each outer bushing  46  is arranged within the respective aperture  86  between the outer vane platform  40  and the respective outer shaft  106 . The inner bushing end  122  may be flush with (or recessed from) the inner platform side  82 . The outer bushing end  124  may be flush with (or recessed from) the outer platform side  84 . These bushings  44  and  46  respectively provide buffers between the vane platforms  38  and  40  and the shafts  104  and  106 . 
     One or more of the inner bushings  44  may be respectively fixedly connected to the inner shafts  104  or the inner vane platform  38 . The inner bushings  44 , for example, may be respectively press fit onto/into, bonded (e.g., welded, brazed or otherwise adhered) to and/or mechanically fastened to the inner shafts  104  or the inner vane platform  38 . Such “fixed connections” may substantially prevent the inner bushings  44  from respectively moving along or rotating about the second axes  58 . Fixed connections between the inner bushings  44  and the inner shafts  104  may substantially prevent sliding between the bushings  44  and shafts  104 . These bushings  44  therefore may reduce or prevent frictional wear to the shafts  104 . Each inner bushing  44  also increases the affective outer surface area of the respective inner shaft  104  and therefore distributes loads between the inner vane platform  38  and the shaft  104  over a greater area. Fixed connections between the inner bushings  44  and the inner vane platform  38  may substantially prevent sliding between the bushings  44  and platform  38 . These bushings  44  therefore may reduce or prevent frictional wear to the platform  38 . Thus, the inner bushings  44  may be replaced during maintenance rather than replacing or refurbishing the adjustable stator vanes  42  or the inner vane platform  38 . 
     Alternatively, one or more of the inner bushings  44  may be respectively connected to the inner shafts  104  or the inner vane platform  38  in a manner that constrains movement of the bushings  44  about and/or constrains movement of the bushings  44  along the second axes  58 . The inner bushings  44 , for example, may be axially retained within the apertures  56 , and constrained from rotating more than between zero and about plus or minus (+/−) six degrees about the respective second axes  58 . 
     One or more of the outer bushings  46  may be respectively fixedly connected to the outer shafts  106  or the outer vane platform  40 . The outer bushings  46 , for example, may be respectively press fit onto/into, bonded to and/or mechanically fastened to the outer shafts  106  or the outer vane platform  40 . Such “fixed connections” may substantially prevent the outer bushings  46  from respectively moving along or rotating about the second axes  58 . Fixed connections between the outer bushings  46  and the outer shafts  106  may substantially prevent sliding between the bushings  46  and the shafts  106 . These bushings  46  therefore may reduce or prevent frictional wear to the shafts  106 . Each outer bushing  46  also increases the affective outer surface area of the respective outer shaft  106  and therefore distributes loads between the outer vane platform  40  and the shaft  106  over a greater area. Fixed connections between the outer bushings  46  and the outer vane platform  40  may substantially prevent sliding between the bushings  46  and platform  40 . These bushings  46  therefore may reduce or prevent frictional wear to the platform  40 . Thus, the outer bushings  46  may be replaced during maintenance rather than replacing or refurbishing the adjustable stator vanes  42  or the outer vane platform  40 . 
     Alternatively, one or more of the outer bushings  46  may be respectively connected to the outer shafts  106  or the outer vane platform  40  in a manner that constrains movement of the bushings  46  about and/or constrains movement of the bushings  46  along the respective second axes  58 . The outer bushings  46 , for example, may be axially retained within the apertures  86 , and constrained from rotating more than between zero and about plus or minus six degrees about the respective second axes  58 . 
     One or more of the inner and/or outer bushings  44  and  46  may each include a coated bearing surface that slidably engages another body, such as the respective shaft or vane platform. In the embodiment of  FIG. 5 , for example, each of the inner bushings  44  is connected to the respective inner shaft  104 . Each of the inner bushings  44  includes a coated bearing surface  132  that slidably engages the inner vane platform  38 . The coating may be a hard coating that reduces wear to the inner vane platform  38  and/or to the bushings  44 . Such a hard coating may include one or more of the following materials: chromium, tungsten, cobalt, chromium carbide, tungsten carbide, nickel, copper and/or aluminum. The present invention, however, is not limited to any particular hard coating materials or types of coatings. 
     One or more of the inner and/or outer bushings  44  and  46  may be respectively (e.g., fixedly) connected to the shafts  104  and  106  with anti-rotation and/or axial retainment elements such as fasteners (e.g., bolts or pins), keys, protrusions or compression sleeves. In some embodiments, for example as illustrated in  FIG. 6 , one or more of the inner bushings  44  each includes an annular sleeve  134  and an annular inner flange  136 . The inner shaft  104  extends axially through the sleeve  134 , and a distal end  138  of the inner shaft  104  engages the flange  136 . A fastener  140  extends through a bore of the flange  136  and into the inner shaft  104 . The fastener  140  clamps the flange  136  against the distal end  138 , thereby axially and/or rotatably constraining movement of the bushing  44 . The shaft  104  may include a threaded insert  142  to receive the fastener  140  where, for example, the shaft  104  is made from a relatively soft material such as aluminum or aluminum alloy. 
     One or more of the inner and/or outer bushings  44  and  46  may be respectively (e.g., fixedly) connected to the vane platforms  38  and  40  with anti-rotation and/or axial retainment elements such as fasteners, keys, protrusions or compression sleeves. In some embodiments, for example as illustrated in  FIGS. 7-13 , one or more of the inner bushings  44  each includes an annular sleeve  144  and one or more protrusions  146 . These protrusions  146  extend into respective apertures  148  in the inner vane platform  38 . The protrusions  146  therefore axially and/or rotatably constrain movement of the bushing  44 . One or more of the protrusions  146  may respectively extend radially from the sleeve into the apertures  148  as illustrated in  FIGS. 7 and 12 . Alternatively, one or more of the protrusions  146  may respectively extend axially from the sleeve into the apertures  148  as illustrated in  FIG. 13 . Referring to  FIGS. 7 and 8 , a portion  150  of each aperture  148  may extend into the first platform segment  66  from the first mate face  70  and/or the respective aperture  56 . Referring to  FIG. 8 , a portion  152  of each aperture  148  may extend into the second platform segment  68  from the second mate face  72  and/or the respective aperture  56 . Referring to  FIGS. 8-11 , one or more of the protrusions  146  and/or one or more of the apertures  148  may each have an arcuate (e.g., crescent or semi-annular) cross-sectional geometry. Referring to  FIGS. 12 and 13 , one or more of the protrusions  146  and/or one or more of the apertures  148  may each have a polygonal (e.g., square, rectangular or triangular) cross-sectional geometry. 
     In some embodiments, for example as illustrated in  FIG. 14 , a pin  154  extends through the inner vane platform  38  and into an aperture  156  in the respective inner bushing  44 . This pin  154  may therefore axially and/or rotatably constrain movement of the bushing  44 . 
     In some embodiments, for example as illustrated in  FIG. 15 , an annular ring  158  is seated within a channel  160  in the inner vane platform  38 . A portion of the ring  158  extends through the inner vane platform  38  and into an aperture  162  in each respective inner bushing  44 A. This ring  158  may therefore axially and/or rotatably constrain movement of the bushing  44 A. 
     In some embodiments, for example as illustrated in  FIG. 16 , a compression sleeve  164  such as an elastic polymer (e.g., rubber) sleeve is arranged within each aperture  56  between the inner vane platform  38  and the respective inner bushing  44 . The compression sleeve  164  may exert a radial force against both the inner vane platform  38  and the respective inner bushing  44 . The compression sleeve  164  may therefore axially and/or rotatably constrain movement of the bushing  44 . 
     Referring to  FIG. 17 , the variable area vane arrangement  36  may include at least one set of first and second inner bushings  44 A and  44 B. The first inner bushing  44 A is (e.g., fixedly) connected to the inner vane platform  38 . The second inner bushing  44 B is (e.g., fixedly) connected to the inner shaft  104 . The first and the second inner bushings  44 A and  44 B form a journal bearing assembly, which may reduce wear to both the inner shaft  104  and the inner vane platform  38 . Similarly, the variable area vane arrangement  36  may include at least one set of first and second outer bushings (not shown). 
     The variable area vane arrangement  36  may be included in various turbine engine configurations other than the one described above. One or more of the variable area vane arrangements  36 , for example, may be included in a geared turbine engine  166  as illustrated in  FIG. 18 . The engine  166  includes a fan section  168 , a low pressure compressor (LPC) section  169 , a high pressure compressor (HPC) section  170 , a combustor section  171 , a high pressure turbine (HPT) section  172 , and a low pressure turbine (LPT) section  173 . These engine sections  168 - 173  are arranged sequentially along an axis  22  and housed within an engine case  34 . 
     Each of the engine sections  168 - 170 ,  172  and  173  includes a respective rotor  174 - 178 . Each of the rotors  174 - 178  includes a plurality of rotor blades arranged circumferentially around and connected (e.g., mechanically fastened, welded, brazed or otherwise adhered) to one or more respective rotor disks. The fan rotor  174  is connected to a gear train  180 ; e.g., an epicyclic gear train. The gear train  180  and the LPC rotor  175  are connected to and driven by the LPT rotor  178  through a low speed shaft  180 . The HPC rotor  176  is connected to and driven by the HPT rotor  177  through a high speed shaft  182 . The low and high speed shafts  180  and  182  are rotatably supported by a plurality of bearings. Each of the bearings is connected to the engine case  34  by at least one stator such as, for example, an annular support strut. 
     Air enters the engine through the airflow inlet  24 , and is directed through the fan section  168  and into an annular core gas path  184  and an annular bypass gas path  186 . The air within the core gas path  184  may be referred to as “core air”. The air within the bypass gas path  186  may be referred to as “bypass air” or “cooling air”. The core air is directed through the engine sections  169 - 173  and exits the engine  166  through the airflow exhaust  26 . Within the combustion section  171 , fuel is injected into and mixed with the core air and ignited to provide forward engine thrust. The bypass air is directed through the bypass gas path  186  and out of the engine  166  to provide additional forward engine thrust or reverse thrust via a thrust reverser. The bypass air may also be utilized to cool various turbine engine components within one or more of the engine sections  169 - 173 . 
     The terms “forward”, “aft”, “inner” and “outer” are used to orientate the components of the variable area vane arrangement  36  described above relative to the turbine engines and their axes. A person of skill in the art will recognize, however, one or more of these components may be utilized in other orientations than those described above. The present invention therefore is not limited to any particular variable area vane arrangement spatial orientations. 
     A person of skill in the art will recognize the variable area vane arrangement  36  may be included in various types of rotational equipment other than a turbine engine. A person of skill in the art will also recognize one or more of the bushings may be included in devices other than a variable area vane arrangement. The bushings, for example, may be included where a shaft of an actuator is rotatably connected to body such as a case housing internal components of the actuator. The present invention therefore is not limited to any particular types or configurations of rotational equipment or other devices. 
     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 within 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.