Composite rocker shaft with integrated oil galleries

Abstract

A rocker shaft for oiling engine components includes an outer tube and an insert extending through the outer tube. The insert defines a plurality of lumens. Each of the plurality of lumens extends through the insert and is configured to receive oil from an oil pump. An engine system includes a cylinder block, a cylinder head connected to the cylinder block, an overhead structure connected to the cylinder head, and a rocker shaft connected to the overhead structure such that a first end of a rocker arm connected to the rocker shaft is positioned above a cylinder of the cylinder block. A method of manufacturing the rocker shaft includes providing an outer tube and an insert, placing the insert in the outer tube, and aligning each of a plurality of lumens defined by the insert with a plurality of outer oil holes defined by the outer tube.

1 . A rocker shaft for oiling engine components, comprising:
 an outer tube defining a plurality of outer fastener openings formed therein;   an insert extending through the outer tube, the insert defining:
 a plurality of inner fastener openings formed therein, the plurality of outer fastener openings and the plurality of inner fastener openings configured to receive a fastener for securing the rocker shaft to an engine component; and 
 a plurality of lumens formed therein, each of the plurality of lumens extending through the insert, each of the plurality of lumens configured to receive oil from an oil pump. 
   
     
     
         2 . The rocker shaft of  claim 1 , wherein the outer tube defines a plurality of outer oil holes formed therein, the plurality of outer oil holes allowing the oil from the plurality of lumens to exit the outer tube. 
     
     
         3 . The rocker shaft of  claim 1 , wherein the insert comprises a material selected from the group consisting of aluminum, steel, ceramic, a polyamide, a polymer, and a polymer composite. 
     
     
         4 . The rocker shaft of  claim 1 , wherein at least one of the plurality of lumens is formed between the insert and the outer tube. 
     
     
         5 . The rocker shaft of  claim 1 , wherein at least one of the plurality of lumens is formed in the insert. 
     
     
         6 . The rocker shaft of  claim 5 , wherein the insert defines a plurality of inner oil holes formed therein, the plurality of inner oil holes allowing the oil from the at least one of the plurality of lumens formed in the insert to exit the insert, and the outer tube defines a plurality of outer oil holes formed therein, the plurality of outer oil holes allowing the oil from the plurality of lumens to exit the outer tube. 
     
     
         7 . The rocker shaft of  claim 1 , wherein each of the plurality of lumens has a same cross-sectional shape. 
     
     
         8 . The rocker shaft of  claim 1 , wherein at least one of the plurality of lumens has a cross-sectional shape different from that of at least another of the plurality of lumens. 
     
     
         9 . The rocker shaft of  claim 1 , wherein at least one of the plurality of lumens extends through the length of the outer tube. 
     
     
         10 . The rocker shaft of  claim 1 , wherein the outer tube defines an outer recessed groove formed therein and the insert defines an inner recessed groove formed therein, the outer recessed groove and the inner recessed groove allowing the rocker shaft to be attached to an engine component. 
     
     
         11 . (canceled) 
     
     
         12 . The rocker shaft of  claim 1 , further comprising a plug positioned in at least one of the plurality of lumens, the plug configured to allow separate oil signal pulses to a portion of the rocker shaft for variable valve actuation. 
     
     
         13 . An engine system, comprising:
 a cylinder block;   a cylinder head connected to the cylinder block;   an overhead structure connected to the cylinder head such that the cylinder head is positioned between the cylinder block and the overhead structure; and   a rocker shaft connected to the overhead structure such that a first end of a rocker arm connected to the rocker shaft is positioned above a cylinder of the cylinder block, the rocker shaft comprising:
 an outer tube defining a plurality of outer fastener openings formed therein; and 
 an insert extending through the outer tube, the insert defining:
 a plurality of inner fastener openings formed therein, the plurality of outer fastener openings and the plurality of inner fastener openings configured to receive a fastener for securing the rocker shaft to the overhead structure; 
 a plurality of lumens formed therein, each of the plurality of lumens extending through the insert, each of the plurality of lumens configured to receive oil from an oil pump. 
 
   
     
     
         14 . The engine system of  claim 13 , wherein the outer tube defines a plurality of outer oil holes formed therein, the plurality of outer oil holes allowing the oil from the plurality of lumens to exit the outer tube. 
     
     
         15 . The engine system of  claim 13 , wherein the insert comprises a material selected from the group consisting of aluminum, steel, ceramic, a polyamide, a polymer, and a polymer composite. 
     
     
         16 . The engine system of any of  claim 13 , wherein at least one of the plurality of lumens is formed between the insert and the outer tube. 
     
     
         17 . The engine system of any of  claim 13 , wherein at least one of the plurality of lumens is formed in the insert. 
     
     
         18 . The engine system of  claim 17 , wherein the insert defines a plurality of inner oil holes formed therein, the plurality of inner oil holes allowing the oil from the at least one of the plurality of lumens formed in the insert to exit the insert, and the outer tube defines a plurality of outer oil holes formed therein, the plurality of outer oil holes allowing the oil from the plurality of lumens to exit the outer tube. 
     
     
         19 . The engine system of any of  claim 13 , wherein each of the plurality of lumens has a same cross-sectional shape. 
     
     
         20 . The engine system of any of  claim 13 , wherein at least one of the plurality of lumens has a cross-sectional shape different from that of at least another of the plurality of lumens. 
     
     
         21 . The engine system of any of  claim 13 , wherein at least one of the plurality of lumens extends through the length of the outer tube. 
     
     
         22 . The engine system of  claim 13 , wherein the outer tube defines an outer recessed groove formed therein and the insert defines an inner recessed groove formed therein, the outer recessed groove and the inner recessed groove allowing the rocker shaft to be attached to the overhead structure. 
     
     
         23 . (canceled) 
     
     
         24 . The engine system of  claim 23 , further comprising a plug positioned in at least one of the plurality of lumens, the plug configured to allow separate oil signal pulses to a portion of the rocker shaft for variable valve actuation. 
     
     
         25 . A method of manufacturing a rocker shaft for oiling engine components, the method comprising:
 providing an outer tube defining a plurality of outer fastener openings formed therein, and an insert defining a plurality of inner fastener openings formed therein;   placing the insert in the outer tube;   aligning the outer tube with the insert so that (i) each of a plurality of lumens defined by the insert and extending through the insert are aligned with a plurality of outer oil holes defined by the outer tube, and (ii) the plurality of outer fastener openings are aligned with the plurality of inner fastener openings.   
     
     
         26 . The method of  claim 25 , wherein the step of placing the insert in the outer tube comprises using press fit to place the insert in the outer tube. 
     
     
         27 . The method of  claim 25 , wherein each of the plurality of lumens is configured to receive oil from an oil pump and each of the plurality of outer oil holes allows the oil from the plurality of lumens to exit the outer tube. 
     
     
         28 . The rocker shaft of  claim 1 , wherein a width of at least one lumen of the plurality of lumens normal to a flow direction therethrough is greater than a width of at least one of the plurality of inner fastener openings. 
     
     
         29 . The rocker shaft of  claim 1 , wherein at least one of the plurality of lumens defines a pathway have at least one bend proximate to at least one of the plurality of inner fastener openings.