Abstract:
An aircraft front nose landing gear having both elastomeric and nonelastomeric elements is provided along with a method of making the same. The aircraft front nose landing gear includes the ability to reduce/inhibit oscillating shimmy rotation vibrations. The method further provides for making a landing gear with a shimmy damper for further reducing oscillating rotations.

Description:
CROSS REFERENCE 
       [0001]    This application is a continuation of co-pending U.S. patent application Ser. No. 12/583,657 filed on Aug. 24, 2009 which is a division of U.S. patent application Ser. No. 11/038,851 filed on Jan. 19, 2005, the benefit of both of which is claimed and both of which are incorporated by reference. This application also claims the benefit of, and incorporates by reference, U.S. Provisional Patent Application No. 60/537,704 filed on Jan. 20, 2004. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to an aircraft front nose landing gear and a method of making an aircraft front nose landing gear. More particularly the invention relates to aircraft landing gear with reduced oscillating shimmy rotation vibrations and methods for making a landing gear with a shimmy damper for reducing oscillating rotations. 
       BACKGROUND OF THE INVENTION 
       [0003]    There is a need for an effective and economical means for making aircraft landing gear with improved performance and reliability. There is a need for economically feasible aircraft landing gear with a shimmy damper. There is a need for a robust system and method of making an aircraft landing gear shimmy damper for inhibiting oscillating rotations. 
       SUMMARY 
       [0004]    The invention includes an aircraft vehicular front wheel landing gear assembly. The landing gear assembly includes a nonelastomeric outer upper strut tubular member having an inner axial center bore with a tubular cylindrical frictional interface inner surface segment. The landing gear assembly includes a nonelastomeric inner lower strut member having an outer bonding surface segment. The nonelastomeric inner member is rotationally received in the outer strut member inner axial center bore with the nonelastomeric inner strut member rotatable within said outer strut member. The landing gear assembly includes an elastomeric surface effect damper member encompassing the nonelastomeric inner strut member outer bonding surface segment. The elastomeric surface effect damper member has an inner bonding surface segment and an outer elastomer surface. The elastomeric surface effect damper inner bonding surface segment is bonded to the nonelastomeric inner strut member outer bonding surface segment. The landing gear assembly includes a surface effect lubricant disposed between the elastomeric surface effect damper outer elastomer surface and the nonelastomeric outer strut member frictional interface inner surface segment with the elastomeric surface effect damper outer elastomer surface engaging the nonelastomeric outer strut member frictional interface inner surface segment and inhibiting an oscillating shimmy rotation of the nonelastomeric inner lower strut member. 
         [0005]    The invention includes a method of making an aircraft vehicular front wheel landing gear assembly. The method includes providing a nonelastomeric outer upper strut tubular member having an inner axial center bore with a tubular cylindrical frictional interface inner surface segment. The method includes providing a nonelastomeric inner lower strut member rotationally receivable in the outer strut member inner axial center bore with the nonelastomeric inner strut member rotatable within said outer strut member. The nonelastomeric inner lower strut member has an outer bonding surface segment. The method includes bonding an elastomeric surface effect damper member to said nonelastomeric inner strut member outer bonding surface segment, with said elastomeric surface effect damper member having an outer elastomer surface distal from said nonelastomeric inner strut member outer bonding surface segment. The method includes rotationally receiving said nonelastomeric inner strut rotationally receivable member in said outer strut member inner axial center bore with said nonelastomeric inner strut member rotatable within said outer strut member with said elastomeric surface effect damper outer elastomer surface engaging said nonelastomeric outer strut member frictional interface inner surface segment and inhibiting an oscillating shimmy rotation of said nonelastomeric inner lower strut member. 
         [0006]    The invention includes a method of making a shimmy damper for damping a rotating oscillation. The method includes providing a nonelastomeric outer upper tubular member having an inner axial center bore with a tubular cylindrical frictional interface inner surface segment. The method includes providing a nonelastomeric inner lower member rotationally receivable in said outer member inner axial center bore with said nonelastomeric inner member rotatable within said outer member. The nonelastomeric inner member has an outer bonding cylindrical surface segment. The method includes bonding an elastomeric surface effect damper member to said nonelastomeric inner member outer bonding cylindrical surface segment, with said elastomeric surface effect damper member having an outer grooved elastomer surface distal from said nonelastomeric inner member outer bonding cylindrical surface segment. The method includes rotationally receiving said nonelastomeric inner member in said outer member inner axial center bore with said nonelastomeric inner member rotatable within said outer member with said elastomeric surface effect damper outer grooved elastomer surface engaging said nonelastomeric outer member frictional interface inner surface segment and inhibiting an oscillating shimmy rotation of said nonelastomeric inner member. 
         [0007]    The invention includes a shimmy damper for damping a rotating oscillation. The shimmy damper includes a nonelastomeric outer upper tubular member having an inner axial center bore with a tubular cylindrical frictional interface inner surface segment and a nonelastomeric inner lower member having an outer bonding cylindrical surface segment with the nonelastomeric inner member rotationally received in the outer member inner axial center bore with the nonelastomeric inner member rotatable within said outer tubular member. The shimmy damper includes an elastomeric surface effect damper member encompassing said nonelastomeric inner member outer bonding cylindrical surface segment, said elastomeric surface effect damper member having an inner bonding cylindrical surface segment and an outer grooved elastomer surface, said elastomeric surface effect damper inner bonding cylindrical surface segment bonded to said nonelastomeric inner member outer bonding cylindrical surface segment. The shimmy damper includes a surface effect lubricant, said surface effect lubricant disposed between said elastomeric surface effect damper outer grooved elastomer surface and said nonelastomeric outer member frictional interface inner surface segment with said elastomeric surface effect damper outer grooved elastomer surface engaging said nonelastomeric outer member frictional interface inner surface segment and inhibiting an oscillating shimmy rotation of said nonelastomeric inner member. 
         [0008]    The invention includes a method of making a rotating oscillation damper for damping a rotating oscillation. The method includes providing a nonelastomeric outer tubular member having an inner axial center bore with a tubular cylindrical frictional interface inner surface segment. The method includes providing a nonelastomeric inner member rotationally receivable in said outer member inner axial center bore with said nonelastomeric inner member rotatable within said outer member, said nonelastomeric inner member having an outer bonding cylindrical surface segment. The method includes providing an elastomeric surface effect damper member mold for receiving said nonelastomeric inner member, said mold including an outer surface groove relief distal from said nonelastomeric inner member outer bonding cylindrical surface segment. The method includes providing an elastomer and molding said elastomer to said nonelastomeric inner member inside said mold to provide an elastomeric surface effect damper member bonded to said nonelastomeric inner member outer bonding cylindrical surface segment, with said elastomeric surface effect damper member having an outer grooved elastomer surface distal from said nonelastomeric inner member outer bonding cylindrical surface segment. The method includes rotationally receiving said nonelastomeric inner member in said outer member inner axial center bore with said nonelastomeric inner member rotatable within said outer member with said elastomeric surface effect damper outer grooved elastomer surface engaging said nonelastomeric outer member frictional interface inner surface segment and inhibiting an oscillating rotation of said nonelastomeric inner member. The invention includes making a rotating oscillation damper by providing a nonelastomeric outer tubular member having an inner axial center bore with a tubular cylindrical frictional interface inner surface segment, providing a nonelastomeric inner member rotationally receivable in said outer member inner axial center bore with said nonelastomeric inner member rotatable within said outer member, said nonelastomeric inner member having an outer bonding cylindrical surface segment, bonding an elastomeric surface effect damper member to said nonelastomeric inner member outer bonding surface segment with said elastomeric surface effect damper member having an outer elastomer surface distal from said nonelastomeric inner member outer bonding surface segment, receiving said nonelastomeric inner member in said outer member inner axial center bore with said nonelastomeric inner member rotatable within said outer member with said elastomeric surface effect damper outer elastomer surface engaging said nonelastomeric outer member frictional interface inner surface segment and inhibiting an oscillating rotation of said nonelastomeric inner member. 
         [0009]    It is to be understood that both the foregoing general description and the following detailed description are exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principals and operation of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows an embodiment of the invention. 
           [0011]      FIG. 2  shows an embodiment of the invention. 
           [0012]      FIG. 3  shows an embodiment of the invention. 
           [0013]      FIG. 4  shows an embodiment of the invention. 
           [0014]      FIG. 5  shows an embodiment of the invention. 
           [0015]      FIG. 6  shows an embodiment of the invention. 
           [0016]      FIG. 7  shows an embodiment of the invention. 
           [0017]      FIG. 8  shows an embodiment of the invention. 
           [0018]      FIG. 9  shows an embodiment of the invention. 
           [0019]      FIG. 10  shows an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
         [0021]    Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. 
         [0022]    The invention includes an aircraft vehicular front landing gear assembly  10  for an aircraft  20 . The landing gear assembly  10  is comprised of a nonelastomeric outer upper strut shaft tubular member  12  having an inner axial center bore  22  with a tubular cylindrical frictional interface inner surface segment  24 . Preferably the nonelastomeric outer upper strut shaft tubular member  12  is comprised of a metal tube. The landing gear assembly  10  is comprised of a nonelastomeric inner lower strut shaft tubular member  11  having an outer bonding cylindrical surface segment  26  with the nonelastomeric inner lower strut shaft member rotationally received in the outer strut member inner axial center bore  22  with the nonelastomeric inner strut member  11  rotatable within the outer strut member  12 . Preferably the nonelastomeric inner strut member  11  is comprised of a metal tube. The landing gear assembly  10  is comprised of an elastomeric surface effect damper member  28  encompassing the nonelastomeric inner strut member outer bonding cylindrical surface segment  26 . The elastomeric surface effect damper member  28  has an inner bonding cylindrical surface segment  30  and an outer grooved elastomer surface  32 . The elastomeric surface effect damper inner bonding surface segment  30  is bonded to the nonelastomeric inner strut member outer bonding surface segment  26 . The landing gear assembly  10  includes a surface effect lubricant  34 , the surface effect lubricant  34  disposed between the elastomeric surface effect damper outer grooved elastomer surface  32  and the nonelastomeric outer strut member frictional interface inner surface segment  24  with the elastomeric surface effect damper outer grooved elastomer surface  32  engaging the nonelastomeric outer strut member frictional interface inner surface segment  24  and inhibiting an oscillating shimmy rotation  36  of the nonelastomeric inner lower strut shaft member  11 . Preferably the nonelastomeric inner lower strut shaft member  11  is grounded to a front nose wheel  17  with the rotation of nonelastomeric inner lower strut shaft member  11  tied and fixed to the steering rotation of the wheel  17 , with the front nose wheel  17  and the nonelastomeric inner lower strut shaft member  11  rotationally actuated by a steering input  38 , such as with steering tubes  15 , steering collar  14 , torque link  13 , lower strut  111  and the nonelastomeric outer upper strut shaft member  12  is rotationally fixed to an aircraft nose front  40  such as with upper strut  112 . Nonelastomeric outer upper strut shaft member  12  is rotationally fixed in that it does not rotate with steering input  38  and/or the front nose wheel  17  that is being turned side to side to steer the aircraft, such as during taxing and ground maneuvers by the aircraft  20 . Nonelastomeric outer upper member  12  is tied and fixed to the structure of the aircraft nose front  40  such as through rotationally fixed upper strut  112 , with nonelastomeric inner lower member  11  rotating relative to outer upper member  12 . Preferably the elastomeric surface effect damper member outer grooved elastomer surface  32  has an upper end  42  and a distal lower end  44  with an elastomer surface groove  46  traversing the elastomer surface from the upper end  42  to the distal lower end  44 , most preferably with groove  46  traversing the elastomer surface from the upper end to the distal lower end with the pattern of a helical spiral. Preferably the elastomeric surface effect damper member outer grooved elastomer surface  32  includes a helical spiral elastomer surface groove  46 . Preferably the elastomeric surface effect damper member outer grooved elastomer surface  32  includes an elastomer surface groove  46 . 
         [0023]    The invention includes a method of making an aircraft vehicular front landing gear assembly  10 . The method includes providing a nonelastomeric metal outer upper strut shaft tubular member  12  having an inner axial center bore  22  with a tubular cylindrical frictional interface inner surface segment  24 . The method includes providing a nonelastomeric metal inner lower strut shaft tubular member  11  rotationally receivable in the outer strut member inner axial center bore  22  with the nonelastomeric inner strut member  11  rotatable within the outer strut member  12 , with the nonelastomeric inner strut member  11  having an outer bonding cylindrical surface segment  26 . The method includes bonding an elastomeric surface effect damper member  28  to the nonelastomeric inner strut member outer bonding cylindrical surface segment  26 , with the elastomeric surface effect damper member  28  having an outer grooved elastomer surface  32  distal from the nonelastomeric inner strut member outer bonding surface segment  26 . The method includes rotationally receiving the nonelastomeric inner lower strut shaft rotationally receivable member  11  in the outer strut member inner axial center bore  22  with the nonelastomeric inner strut member  11  rotatable within the outer strut member  12  with the elastomeric surface effect damper outer grooved elastomer surface  32  engaging the nonelastomeric outer strut member frictional interface inner surface segment  24  and inhibiting an oscillating shimmy rotation  36  of the nonelastomeric inner lower strut member  11 . Preferably the method includes molding the elastomeric surface effect damper member  28  onto the nonelastomeric inner strut member outer bonding cylindrical surface segment  26 . Preferably the method includes providing an elastomeric surface effect damper member mold  60  for receiving the nonelastomeric inner strut member  11 , providing an elastomer  56 , and molding the elastomer  56  to the nonelastomeric inner strut member  11  inside the mold  60 . Preferably the elastomer  56  is comprised of a natural rubber elastomer. In an embodiment the elastomer  56  is comprised of a silicone elastomer. Preferably the mold  60  includes an outer surface groove relief  62  distal from the nonelastomeric inner strut member outer bonding surface segment  26 , preferably the groove relief  62  traversing the elastomer mold cavity surface to provide for a groove  46  traversing the elastomer surface from the upper end  42  to the distal lower end  44 , preferably a helical spiral elastomer surface groove  46  from the upper end to the distal lower end. In an embodiment molding includes providing an elastomer transfer stock  57 , and transferring the elastomer transfer stock  57  under a pressure into the mold  60 , such as through a sprue with the mold comprising close fitting steel metal pieces clamped in place, and vulcanizing curing the elastomer  56  inside the mold  60  under a molding pressure, preferably a molding pressure of at least 1000 psi. Preferably providing the nonelastomeric outer upper strut shaft tubular member  12  includes providing a nonelastomeric outer tubular member  12  with a tubular cylindrical frictional interface inner surface segment  24  having an inside diameter ID, and bonding an elastomeric surface effect damper member to the nonelastomeric inner strut member outer bonding cylindrical surface segment includes bonding an elastomeric surface effect damper member  28  to the nonelastomeric inner strut member outer bonding surface segment  26  to provide a bonded elastomeric surface effect damper member  28  having an outer grooved elastomer surface  32  with an outside diameter OD, with the elastomeric surface effect damper member outer grooved elastomer surface outside diameter OD greater than the nonelastomeric outer upper strut tubular member frictional interface inner surface segment inside diameter ID. Preferably the inside diameter ID of nonelastomeric outer tubular member  12  and the unreceived surface effect damper outside diameter OD of surface effect damper member  28  have a ratio ID/OD≧0.75, preferably ID/OD≧0.80, preferably ID/OD≧0.85, preferably ID/OD≧0.90, preferably ID/OD≧0.92, most preferably ID/OD is in the range of 0.90 to 0.99, preferably with the surface effect damper elastomer having a compression strain less than 10%, prefer less than 8%, preferably less than 7.75% when received inside said nonelastomeric outer tubular member  12 . Preferably the nonelastomeric outer tubular member  12  has a funnel end  23  with a progressively increasing inside diameter to facilitate reception of the nonelastomeric inner strut member  11  with surface effect damper member  28  inside outer tubular member  12 . Preferably after reception of nonelastomeric inner strut member  11  with surface effect damper member  28  inside outer tubular member  12  the relative axial movement of nonelastomeric inner strut member  11  with surface effect damper member  28  along inner axial bore  22  is minimal in that relative axial stroking is minimized. The method includes providing a friction reducing lubricant  34  between the elastomeric surface effect damper outer grooved elastomer surface  32  and the nonelastomeric outer strut member frictional interface inner surface segment  24 . Preferably a friction reducing lubricant grease is disposed between the surfaces, preferably a grease containing a fluorocarbon. Preferably the friction reducing lubricant  34  between the elastomeric surface effect damper outer grooved elastomer surface  32  and the nonelastomeric outer strut member frictional interface inner surface segment  24  is comprised of a silicone lubricant. 
         [0024]    The invention includes method of making a shimmy damper  100  for damping a rotating oscillation  36 . The method includes providing a nonelastomeric outer upper tubular member  12  having an inner axial center bore  22  with a tubular cylindrical frictional interface inner surface segment  24 . The method includes providing a nonelastomeric inner lower shaft member  11  rotationally receivable in the outer member inner axial center bore  22  with the nonelastomeric inner member  11  rotatable within the outer member  12 , with the nonelastomeric inner member  11  having an outer bonding cylindrical surface segment  26 . The method includes bonding an elastomeric surface effect damper member  28  to the nonelastomeric inner member outer bonding cylindrical surface segment  26 , with the elastomeric surface effect damper member  28  having an outer grooved elastomer surface  32  distal from the nonelastomeric inner member outer bonding cylindrical surface segment  26 . The method includes rotationally receiving the nonelastomeric inner member  11  in the outer member inner axial center bore  22  with the nonelastomeric inner member  11  rotatable within the outer member  12  with the elastomeric surface effect damper outer grooved elastomer surface  32  engaging the nonelastomeric outer member frictional interface inner surface segment  24  and inhibiting an oscillating shimmy rotation  36  of the nonelastomeric inner member  11 . 
         [0025]    The invention includes a shimmy damper  100  for damping a rotating oscillation  36 . The shimmy damper  100  is comprised of a nonelastomeric metal outer upper tubular member  12  having an inner axial center bore  22  with a tubular cylindrical frictional interface inner surface segment  24 . The shimmy damper  100  is comprised of a nonelastomeric metal inner lower member  11  having an outer bonding cylindrical surface segment  26 , the nonelastomeric inner member  11  rotationally received in the outer member inner axial center bore  22  with the nonelastomeric inner member  11  rotatable within the outer tubular member  12 . The shimmy damper  100  is comprised of an elastomeric surface effect damper member  28  encompassing the nonelastomeric inner member outer bonding cylindrical surface segment  26 , with the elastomeric surface effect damper member  28  having an inner bonding cylindrical surface segment  30  and an outer grooved elastomer surface  32 . The elastomeric surface effect damper inner bonding cylindrical surface segment  30  is bonded to the nonelastomeric inner member outer bonding cylindrical surface segment  26 . The shimmy damper  100  is comprised of a surface effect lubricant  34  disposed between the elastomeric surface effect damper outer grooved elastomer surface  32  and the nonelastomeric outer member frictional interface inner surface segment  24  with the elastomeric surface effect damper outer grooved elastomer surface  32  engaging the nonelastomeric outer member frictional interface inner surface segment  24  and inhibiting an oscillating shimmy rotation of the nonelastomeric inner member. 
         [0026]    The invention includes a method of making a rotating oscillation damper  100  for damping a rotating oscillation  36 . The method includes providing a nonelastomeric metal outer tubular member  12  having an inner axial center bore  22  with a tubular cylindrical frictional interface inner surface segment  24  and providing a nonelastomeric metal inner member  11  rotationally receivable in the outer member inner axial center bore  22  with the nonelastomeric inner member  11  rotatable within the outer member  12 . The nonelastomeric inner member  11  has an outer bonding cylindrical surface segment  26 , and the method includes providing an elastomeric surface effect damper member mold  60  for receiving the nonelastomeric inner member  11 , with the mold including an outer surface groove relief  62  distal from the nonelastomeric inner member outer bonding cylindrical surface segment  26 , preferably with the groove relief traversing the elastomer surface mold cavity from an upper end  42  to a distal lower end  44 . Preferably the outer surface groove relief  62  has a helical spiral pattern for producing an elastomer surface groove  46 . The method includes providing an elastomer  56  and molding the elastomer to the nonelastomeric metal inner member  11  inside the mold  60  to provide a an elastomeric surface effect damper member  28  bonded to the nonelastomeric inner member outer bonding cylindrical surface segment  26 , with the elastomeric surface effect damper member  28  having an outer grooved elastomer surface  32  distal from the nonelastomeric inner member outer bonding cylindrical surface segment. The method includes receiving the nonelastomeric inner member  11  in the outer member inner axial center bore  22  with the nonelastomeric inner member  11  rotatable within the outer member  12  with the elastomeric surface effect damper outer grooved elastomer surface  32  engaging the nonelastomeric outer member frictional interface inner surface segment  24  and inhibiting an oscillating rotation  36  of the nonelastomeric inner member  11 . 
         [0027]    It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.