Abstract:
A cylinder retainer is provided. The cylinder includes: a retainer body having an exterior end and an interior end; a bearing surface located on the retainer body; and an oiler located in a recess in the retainer body. A method of lubricating a rod may be provided. The method may include: contacting an oiler with the rod; and locating a bearing surface on a cylinder retainer between a seal configured to keep fluid located on a surface of the rod in a cylinder and the oiler.

Description:
[0001]    This application claims the benefit of a provisional U.S. patent application entitled Actuation Rod Lubrication System And Method, having a Ser. No. 62/027,350, filed Jul. 22, 2014. The disclosure of this application is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to hydraulic cylinders. More particularly, the present invention relates to lubricating the rod in a hydraulic cylinder. 
       BACKGROUND OF THE INVENTION 
       [0003]    Many hydraulic cylinders involve an internal piston that is moved back and forth along the length of the cylinder. A actuation rod is often attached to the cylinder and the rod moves in and out of the cylinder as the piston moves. The actuation rod is often connected to structure outside of the cylinder that moves when the rod moves. Often, a wiper is located near the end of the piston into which the rod enters. The wiper is used to clean the rod of dirt, debris, and any foreign matter before the rod enters the hydraulic cylinder. 
         [0004]    Inside of the hydraulic cylinder is a seal that is often used to seal against the rod and prevent hydraulic fluid from the hydraulic cylinder from moving out the hydraulic cylinder along with the rod. However, a drawback of the seal is that the rod is dried once it moves past the seal and therefore is not lubricated as the rod moves past or rubs the structure of the hydraulic cylinder as it moves in and out of the cylinder. 
         [0005]    A lack of lubrication along the rod, as it moves past the structure of the hydraulic cylinder, can create wear on the surface of the rod. This wear problem can be exacerbated when the rod is subject to side loads. Side loads may occur where forces acting on the rod in a direction not axial with the rod. These side loads can cause the rod to rub against the structure of the hydraulic cylinder as the rod moves in and out of the hydraulic cylinder. 
         [0006]    Accordingly, it is desirable to provide a method and apparatus that provides lubrication for the rod. 
       SUMMARY OF THE INVENTION 
       [0007]    The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect, in some embodiments, a method and/or an apparatus is provided that provides lubrication for the rod in a location such that the rod is lubricated along the bearing surface of the retainer and neither the seal nor the wiper removes the lubrication from the rod at the location along the bearing surface. 
         [0008]    In accordance with one embodiment of the present invention, a hydraulic cylinder retainer is provided. The hydraulic cylinder includes: a retainer body having an exterior end and an interior end; a bearing surface located on the retainer body; and an oiler located in a recess in the retainer body. 
         [0009]    In accordance with another embodiment of the present invention, a method of lubricating a rod may be provided. The method may include: contacting an oiler with the rod; and locating a bearing surface on a hydraulic cylinder retainer between a seal configured to keep hydraulic fluid located on a surface of the rod in a hydraulic cylinder and the oiler. 
         [0010]    In accordance with yet another embodiment of the present invention, a hydraulic cylinder retainer may be provided. The hydraulic cylinder retainer may include: a retainer body having an exterior end and an interior end; a bearing surface located on the retainer body; and a means for lubricating located in a recess in the retainer body. 
         [0011]    There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
         [0012]    In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. While this disclosure has primarily discusses hydraulic cylinders, one of ordinary skill the art after reviewing this disclosure will understand that various principles of this disclosure may be applied to a variety of cylinders. For example, pneumatic cylinders, gas filled cylinders, liquid filled cylinders, or any other fluid filled cylinders that move a piston may be used in accordance with the disclosure herein. The principles described herein are not limited to hydraulic cylinders only that they are primarily discussed herein as an example. 
         [0013]    The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
         [0014]    As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a cross-sectional view illustrating a hydraulic cylinder, piston, and rod where the piston is in a first position. 
           [0016]      FIG. 2  is a cross-sectional view illustrating a hydraulic cylinder, piston, and rod where the piston is in a second position. 
           [0017]      FIG. 3  is a partial cross-sectional view of a hydraulic piston retainer in accordance with an embodiment in accordance with the disclosure. 
           [0018]      FIG. 4  is a partial cross-sectional view of a hydraulic piston retainer, and associated components in accordance with the disclosure. 
           [0019]      FIG. 5  is a partial cross-sectional view of a hydraulic piston retainer, and associated components in accordance with an embodiment having a second oiler in accordance with the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides lubrication to a rod when the rod is urging against a bearing surface. In some embodiments, the lubrication system is configured so that neither the seal nor the wiper removes lubrication from the rod before the rod urges against the bearing surface of a retainer. 
         [0021]    An embodiment of the present inventive apparatus is illustrated in  FIGS. 1 and 2 .  FIGS. 1 and 2  illustrate a cross-sectional view of a hydraulic cylinder assembly  111 . The hydraulic cylinder assembly  111  includes a hydraulic cylinder  112  having a housing  113 . The hydraulic cylinder housing  113  defines an interior space  114 . The hydraulic cylinder  112  contains a plug  120  and a retainer  122  to define a substantially fluid tight interior  114 . The retainer  122  need not be a separate piece from the cylinder  112 , but may be part of the cylinder  112  or housing  113  or some other feature. A first port  116  and a second port  118  provide inlet/outlets for hydraulic fluid to enter or leave the interior  114  of the hydraulic cylinder  112 . 
         [0022]    When hydraulic fluid enters the second port  118  and exits the first port  116 , the piston  124  is pushed upward as shown in  FIG. 1 . This causes the rod or shaft  126  to move out of the hydraulic cylinder  112 . When hydraulic fluid enters the first port  116  and exits the second port  118 , the piston is pushed downward as shown in  FIG. 2 . This causes the rod or shaft  126  to move into the hydraulic cylinder  112 . 
         [0023]    As the rod or shaft  126  moves in and out of the hydraulic cylinder  112 , the rod  126  slides against the retainer  122 . Often, the rod  126  is subjected to side loads or, in other words, loads that are not in line with the longitudinal axis of the rod  126 . Side loads cause the rod  126  to urge against the retainer  122 . Wear of the surface  128  of the rod  126  against the retainer  122  can cause damage to the surface  128  of the rod  126  and/or retainer  122 . In order to reduce this wear, various embodiments in accordance with the present disclosure provide a method and system for lubricating the surface  128  of the rod  126 . 
         [0024]    In some embodiments in accordance with the disclosure, a lubrication system is located in the retainer  122  to lubricate the surface  128  of the rod  126 .  FIG. 3  is a partial cross-sectional view of the retainer  122 . One of ordinary skill in the art will understand that the retainer  122  is generally annular in shape. However, only a partial cross-sectional view is present in  FIG. 3 . The cross-sectional view shown in  FIGS. 1 and 2  will communicate to one of ordinary skill in the art after reviewing this disclosure the annular shape of the retainer  122 . 
         [0025]    Returning to  FIG. 3 , a wiper recess  132  is illustrated in the retainer  122 . The wiper recess  132  is located just above a retaining lip  134 . The retaining lip  134  provides structure in the retainer  122  to retain a seal  138  (as shown in  FIG. 4 ) in place.  FIG. 3  illustrates a recess  136  located in the retainer  122  into which the seal  138  (as shown in  FIG. 4 ) resides. The retainer  122  includes a bearing surface  142 . It is the bearing surface  142  which contacts and rubs against the surface  128  of the rod or shaft  126  (not shown in  FIG. 3 ). 
         [0026]    In some embodiments, in accordance with the present disclosure, the rod  126  does not rub against any other portion of the retainer  122  then the bearing surface  142 . 
         [0027]    As shown in  FIG. 3 , the bearing surface  142  and the retainer  122  define a cutout or groove  146 . It is in the cutout or groove  146  that a lubrication system resides for lubricating the surface  128  of the rod  126 . 
         [0028]      FIG. 4  is a partial cross-sectional view of the retainer  122  along with other components set with in the retainer  122 . In addition, the retainer  122  is shown placed in the hydraulic cylinder  112 . The housing  113  is shown as well as in the rod  126 . The surface  128  of the rod  126  is shown to be adjacent to the bearing surface  142  of the retainer  122 . 
         [0029]    A wiper  130  is illustrated in the wiper recess  132  of the retainer  122 . The wiper  130  provides the function of cleaning off any dirt, debris, or any other foreign matter from the surface  128  of the rod  126  as the rod  126  enters the hydraulic cylinder  112 . As shown in  FIG. 4 , the wiper  130  may have a step shape, thus providing a stepped portion  148  of the wiper recess  132 . 
         [0030]    The retainer lip  134  can be seen as located below the wiper  130 . The retainer lip  134  provides structure within the retainer  122  to prevent the seal  138  from being forced out of the hydraulic cylinder  112  due to hydraulic pressure within the interior  114  of the hydraulic cylinder  112  or due to friction from the rod  126  moving out of the hydraulic cylinder  112 . 
         [0031]    The seal  138  resides in the seal recess  136  within the retainer  122 . The seal  138  prevents hydraulic fluid from moving along the surface  128  of the rod  126  to exit the hydraulic cylinder  112 . The seal  138  and the wiper  130  may be relatively well-known in the art and do not merit further discussion herein. 
         [0032]      FIG. 4  also illustrates a lubrication system  144 . In some embodiments, the lubrication system  144  simply consists of felt impregnated or saturated with a lubricant. The lubrication system  144  may simply be referred to as an oiler  144 . In some embodiments, the lubricant may be a lubricating oil. In other embodiments, the lubricant may be a hydraulic fluid used in the hydraulic cylinder  112 . The oiled felt  144  resides in the lubricating system cutout  146  within the retainer  122 . As shown in  FIG. 4 , the oiled felt  144  contacts the surface  128  of the rod  126 . The oiled felt  144  is located below both the wiper  130  and the seal  138 . This location results in the surface  128  of the rod being lubricated by the oiled felt  144  before the rod  126  moves in an outwardly direction illustrated by arrow A. Because the exterior  128  of the rod  126  is lubricated before the exterior  128  contacts the bearing surface  142 , the exterior  128  of the rod  126  is lubricated as it moves out of the hydraulic cylinder  112  along the direction illustrated by arrow A. 
         [0033]    In particular, the surface  128  of the rod  126  that is lubricated by various embodiments in accordance with the present disclosure, is illustrated in  FIG. 4 .  FIG. 4  is a partial cross-sectional view of the retainer  122  showing also part of the rod  126  and the hydraulic cylinder housing  113 . 
         [0034]    The embodiment shown in  FIG. 4  is particularly suitable for single acting cylinders  112  where the single acting hydraulic cylinder  112  urges against a load when the rod  126  moves out of the hydraulic cylinder  112 . The oiled felt  144  only applies a lubricant to the surface  128  of the rod  126  prior to the surface  128  of the rod  126  contacting the bearing surface  142  when the rod  126  is moving out of the hydraulic cylinder  112  as shown by arrow A. When such a hydraulic cylinder  112  has the rod  126  moving in towards the hydraulic cylinder  112 , in the direction opposite of arrow A, then the lubricant or oil is not applied to the rod  126  prior to the rod  126  sliding along the bearing surface  142 . 
         [0035]    A dual acting hydraulic cylinder  112  experiences significant loads on the rod  126  when the rod  126  both moves out of the hydraulic cylinder  112  as indicated by arrow A and into the hydraulic cylinder  112  in a direction opposite of that shown by arrow A. Such dual acting cylinders  112  may benefit from the embodiment shown in  FIG. 4 . However, such hydraulic cylinders  112  will primarily only have the surface  128  of the rod  126  lubricated by the oiled felt  144  prior to the surface  128  of the rod  126  contacting the bearing surface  142  on the retainer  122  when the rod  126  is moving out of the hydraulic cylinder  112  as indicated by arrow A. 
         [0036]    As can be appreciated by one of ordinary skill in the art, it may also be desirable to have a hydraulic cylinder assembly  111  that provides lubrication for the surface  128  of the rod  126  prior to the surface  128  of the rod  126  contacting the bearing surface  142  of the retainer  122 . Such a hydraulic cylinder assembly  111  is illustrated in partial cross-section in  FIG. 5 . 
         [0037]      FIG. 5  is similar to the configuration illustrated in  FIG. 4 . The retainer  122  is located in the housing  113  of the hydraulic cylinder  112 . The inlet  116  is also shown providing access to the interior  114  of the hydraulic cylinder  112 . 
         [0038]    However, a second lubrication system which, in some embodiments, may be oiled felt  150  is located in a second lubrication groove  152  in the retainer  122  as illustrated. In the retainer  122  of the  FIG. 5 , a portion of the rod  126  is seen. The retainer  122  includes a wiper  130  located in the wiper recess  132  and the wiper  130  includes a stepped portion  148 . The retainer  122  also includes a retaining lip  134  having a similar function as described above of retaining the seal  138  in the seal recess  136  as previously described. The retainer  122  includes a bearing surface  142 . However, two lubrication systems which, in some embodiments, may include oiled felt  144  and  150  that reside in lubrication grooves  146  and  152  respectively. 
         [0039]    As shown in  FIG. 5 , the lubrication system  144  is located below the bearing surface  142  in the retainer  122 . Thus, as the surface  128  of the rod  126  moves out of the hydraulic cylinder  112  in the direction of arrow A, the surface  128  receives lubrication from the lubrication system  144  before contacting the bearing surface  142 . In addition, the second lubrication system  150  provides lubrication to the surface  128  of the rod  126  before the surface  128  of the rod  126  rubs along the bearing surface  142  of the retainer  122  when the rod  126  moves into the hydraulic cylinder  112  in a direction opposite to that shown by arrow A. The two lubrication systems  144  and  150  are located below the bearing surface  142  and above the bearing surface  142  to provide the benefit of lubricating the surface  128  of the rod  126  prior to the surface  128  of the rod  126  rubbing against the bearing surface  142 . 
         [0040]    As can be appreciated from the discussion above, and as shown in the figures, some embodiments in the accordance of the present disclosure may include one lubrication system and others may use two. While the illustrated figures show a single lubrication system  144  located below the bearing surface  142  in other embodiments the single lubrication system may be located above the bearing surface  142  similar lubrication system  150 . One of ordinary skill in the art after reviewing this disclosure may select an advantageous place to locate a lubrication system or systems for a given hydraulic cylinder. 
         [0041]    While this disclosure has primarily discusses hydraulic cylinders, one of ordinary skill the art after reviewing this disclosure will understand that various principles of this disclosure may be applied to a variety of cylinders. For example, pneumatic cylinders, gas filled cylinders, liquid filled cylinders, or any other fluid filled cylinders that move a piston may be used in accordance with the disclosure herein. The principles described herein are not limited to hydraulic cylinders only that they are primarily discussed herein as an example. 
         [0042]    The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.