Patent Publication Number: US-2013228235-A1

Title: Lubricating valve train carrier

Description:
BACKGROUND 
     The present disclosure relates to valve train carriers and valve train carrier assemblies. Carrier assemblies have valve train components pre-mounted to carriers. Valve train components, for example rocker arms, hydraulic lash adjusters, valve assemblies and related attachments and mechanisms may be mounted to the carrier, minimizing the number of separate components that must be installed and allowing for more efficient installation of the valve train components. 
     SUMMARY 
     A valve train carrier comprises an enclosed main passage configured to be in pressure communication with pressurized engine oil and an enclosed secondary passage adjacent the main passage. An oil barrier between the main passage and secondary passage is configured to permit oil flow from the main passage to the secondary passage such that the secondary passage receives oil from the main passage at a lower pressure than oil in the main passage. Outlet passages permit discharge of oil from the carrier. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It will be appreciated that the illustrated boundaries of elements in the drawings represent only one example of the boundaries. One of ordinary skill in the art will appreciate that a single element may be designed as multiple elements or that multiple elements may be designed as a single element. 
       Further, in the accompanying drawings and description that follow, like parts are indicated throughout the drawings and description with the same reference numerals, respectively. The figures may not be drawn to scale and the proportions of certain parts have been exaggerated for convenience of illustration. 
         FIG. 1  illustrates a perspective view of an exemplary carrier assembly  100 . 
         FIG. 2  illustrates an exploded view of the carrier assembly  100  illustrated in  FIG. 1 . 
         FIG. 3  illustrates a sectional view along the line  3 - 3  shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The terms “upward,” “downward,” “upper,” and “lower” will be understood to have their normal meanings and will refer to those directions as the drawing figures are normally viewed. 
       FIG. 1  illustrates a perspective view of an exemplary valve train carrier assembly  100  according to the present disclosure. Such a carrier assembly  100  may be used to pre-mount multiple components of a valve train, such as a lash adjuster or rocker arm, allowing for greater efficiency in installing these components in an internal combustion engine. According to one aspect of the present disclosure, multiple rocker arms  110  and lash adjusters  112  are mounted to assembly  100 . 
     Carrier assembly  100  has a carrier  101 . Carrier  101  has a cover  102  in the form of a top plate secured to a main body  104  of the carrier  101  with fasteners  106 , corresponding to five screws. Cover or top plate  102  also has holes  103  disposed over engine block mounts  108  that permit passage of pressurized engine oil through top plate  102 . Carrier  101  shown in  FIG. 1  has four engine block mounts  108  that are secured to the engine block (not shown) when carrier  101  is installed in an internal combustion engine. Adjacent each of the engine block mounts  108  are two rocker arms  110 , one on each side of the engine block mounts  108 . Each rocker arm  110  is mounted to carrier  101  through a lash adjuster  112 . Each lash adjuster  112 , in turn, is placed within a lash adjuster seat or boss  114 , which is part of main body  104 . 
       FIG. 2  illustrates an exploded perspective view of valve train carrier  101  shown in  FIG. 1 . As shown in  FIG. 2 , main body  104  has a top surface  200  that serves as a receiving surface for top plate  102 . Top plate  102  has an upper surface  201  and lower surface  203 , lower surface  203  serving as a carrier body interfacing surface. Top surface  200  of main body  104  has a main groove  204 , a secondary groove  206  that almost completely surrounds main groove  204 , and outlet grooves  208  that extend from secondary groove  206  to one of a first  116  and second  118  lateral surface of main body  104 , the first  116  and second  118  lateral surfaces extending between top plate  102  and a lower surface  120  of carrier  101 . Once top plate  102  is secured to main body  104 , lower surface  203  forms passages with main groove  204 , secondary groove  206  and outlet grooves  208 . As illustrated in  FIG. 3 , main groove  204  and lower surface  203  form an enclosed main passage  300 , secondary groove  206  and lower surface  203  form an enclosed secondary passage  302 , and outlet grooves  208  and lower surface  203  form enclosed outlet passages  304 . Eight outlet passages  304  are distributed along each of first  116  and second  118  lateral surfaces and adjacent top plate  102 . When carrier  101  is assembled, outer surface  122  of carrier  101  comprises upper surface  201  of top plate  102 , first  116  and second  118  lateral surfaces, and lower surface  120  of carrier  101 . 
     With further reference to  FIG. 2 , the four engine block mounts  108  are hollow, each having a passage  202  for receiving a fastener (not shown). The passage  202  adjacent the inlet groove  212  is shaped to allow pressurized engine oil to flow past the fastener (not shown) disposed within the passage  202  during engine operation and reach the inlet groove  212 . The passage  202  adjacent the inlet groove  212  may have, for example, a channel or recess creating a space that allows for oil to pass the fastener (not shown). The passage  202  adjacent inlet groove  212  is in fluid pressure communication (or “pressure communication”) with a main groove  204  through inlet groove  212 , which forms inlet passage  214  with lower surface  203  of top plate  102 . As used herein, “pressure communication” denotes communication of fluid (e.g., engine oil) at the same or substantially the same pressure. Pressurized oil travels from passage  202  through inlet passage  214  to main passage  300  formed by main groove  204 . 
     Secondary groove  206  shown in  FIG. 2  is continuous and substantially surrounds main groove  204 . This configuration of secondary groove  206  permits even oil distribution across the entire secondary passage  302 . Other configurations that permit even oil distribution across one or more secondary passages are also possible. In one such example, several discontinuous secondary passages collect oil from main passage  300 , such as may be the case when multiple inlet grooves  212  supply main passage  300  with pressurized oil. According to one aspect of the present teachings, oil may be supplied through more than one of the engine block mounts  108 . 
     While the illustrated assembly  100  shows main groove  204 , secondary groove  206  and outlet grooves  208  as grooves formed on main body  104 , the present disclosure is not so limited. For example, in an alternative assembly, one or more of a main groove  204 , secondary groove  206  and outlet grooves  208 , or a portion thereof, may be formed in a cover  102  that interfaces an upper surface on main body  104  of an alternative carrier  101 , forming various passages. In yet another assembly, one or more of a main groove  204 , secondary groove  206  and outlet grooves  208  may be formed in both a main body  104  of a carrier  101  and a cover  102 . Still other combinations of grooves disposed on one or both of a main body  104  or cover  102  of a carrier are possible according to the present disclosure. 
       FIG. 3  illustrates a sectional view taken along line  3 - 3  show in  FIG. 1 . A lash adjuster  112  has an outer body  350 , plunger  352 , socket  354  and check ball assembly  356 . Socket passage  358  is in pressure communication with main passage  300  through lash adjuster passage  360 , allowing high pressure oil to enter an internal cavity  362  of lash adjuster  112 . Clip  364  prevents rocker arm  110  from separating from lash adjuster  112 . Lash adjuster  112  is located within lash adjuster seat  114  of main body  104 . While in the illustrated configuration rocker arm  110  is mounted to carrier  101  indirectly through lash adjuster  112 , the present disclosure is not so limited. In one alternative example, rocker arm  110  may be directly, pivotably secured to a carrier  101 . In such an alternative configuration, a lash adjuster or tappet may be disposed elsewhere in the valve train, such as between the cam and rocker arm  110 , or between the valve and rocker arm  110 . 
     As illustrated in  FIG. 3 , main passage  300  is separated from secondary passage  302  by barrier  306 . Barrier  306  forms a narrow, oil permeable seal  310  with lower surface  203  of top plate  102 . When the engine is not operating and any transient oil pressure has worn off, the oil in main passage  300  is not under pressure and thus does not flow across barrier  306 . Under such circumstances, barrier  306  may be in contact with lower surface  203  of top plate  102 . In other aspects of the present disclosure, lower surface  203  of top plate  102  and barrier  306  may form a thin passage through which pressurized engine oil passes from main passage  300  to secondary passage  302 . When the engine is operating and pressurized oil is present in main passage  300 , pressurized oil is able to pass through seal  310 . Seal  310  reduces the pressure of the oil as it passes across seal  310  from main passage  300  to secondary passage  302 . The reduction in pressure is due at least in part to fluid forces within the oil that causes a reduction is pressure as the oil crosses seal  310 . Due to the thinness of seal  310 , frictional forces within the oil reduce the pressure of the oil as it passes from the high pressure main passage  300  to the lower pressure secondary passage  302 . The reduction in pressure has a positive relationship with the sectional width of seal  310 . The greater the distance the oil must traverse across the width of seal  310 , the lower the pressure in secondary passage  302  relative to a particular pressure in main passage  300 . Such a pressure reduction will also occur when a sufficiently narrow passage is formed by barrier  306  and lower surface  203  of top plate  102 . 
     Thus, oil received in secondary passage  302  from main passage  300  is not at the pressure level of pressurized engine oil, but rather at a lower pressure suitable for discharging oil from outlet passages  304  and onto valve train components such as rocker arms  110 . As shown in  FIG. 2 , outlet grooves  208  and outlet passages  304  are disposed above rocker arms  110 . Oil exits carrier  101  as it is discharged from outlet passages  304  directly onto rocker arms  110 , where it can the flow further downward into the valve train, thereby lubricating, for example, rocker arms  110 , the cam (not shown) and the valves and associated valve components (not shown). 
     For the purposes of this disclosure and unless otherwise specified, “a” or “an” means “one or more.” To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. See, Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean “on” or “onto.” Furthermore, to the extent the term “connect” is used in the specification or claims, it is intended to mean not only “directly connected to,” but also “indirectly connected to” such as connected through another component or multiple components. As used herein, “about” will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, “about” will mean up to plus or minus 10% of the particular term. From about X to Y is intended to mean from about X to about Y, where X and Y are the specified values. 
     While the present disclosure illustrates various aspects of the present teachings, and while these teachings have been described in some detail, it is not the intention of the applicant to restrict or in any way limit the scope of the claimed invention to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant&#39;s claimed invention. Moreover, the foregoing teachings are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application.