GB2618552A

GB2618552A - Composite rocker shaft with integrated oil galleries

Info

Publication number: GB2618552A
Application number: GB2206787.0A
Authority: GB
Inventors: A Dods James; A Heald Brett
Original assignee: Cummins Inc
Current assignee: Cummins Inc
Priority date: 2022-05-10
Filing date: 2022-05-10
Publication date: 2023-11-15
Also published as: US20230366333A1

Abstract

A rocker shaft 200 for oiling components of an engine (200 Fig. 1) includes an outer tube 202 and an insert 204 extending through the outer tube. The insert is provided with a plurality of lumens 206, 208, 210, and each of the plurality of lumens extends through the insert and is configured to receive oil from an oil pump. The engine includes a cylinder block (110 Fig. 1), a cylinder head (120 Fig. 1) connected to the cylinder block, an overhead structure (130 Fig. 1) connected to the cylinder head, and a rocker shaft connected to the overhead structure such that a first end (135 Fig. 2) of a rocker arm (134 Fig. 2) connected to the rocker shaft is positioned above a cylinder of the cylinder block. The rocker shaft is manufactured by placing the insert in the outer tube and aligning each of the plurality of lumens in the insert with a plurality of outer oil holes 216, 218, 220 within the outer tube. In use, the oil received by the plurality of lumens may exit the outer tube through the plurality of outer oil holes. The arrangement allows a composite rocker shaft using both extruded/moulded and machined components and does not require expensive and difficult drilling of long and small holes in the rocker shaft.

Description

COMPOSITE ROCKER SHAFT WITH INTEGRATED OIL GALLERIES

TECHNICAL FIELD

100011 The present disclosure relates generally to rocker shafts for use in internal combustion engine systems.

BACKGROUND

100021 For an engine system, it may be desirable to provide lubrication of engine components by providing oil to a rocker shaft. One approach that can be implemented to provide oil lubrication using a rocker shaft is to drill lumens into the rocker shaft. However, in a long rocker shaft, drilling multiple, narrow lumens into the rocker shaft can be expensive and difficult to manufacture. In addition, rocker shafts have generally not been able to be manufactured with lumens that extend the full length of the rocker shaft.

SUMMARY

[0003] According to a first set of embodiments, a rocker shaft comprises an outer tube and an insert extending through the outer tube. The insert defines a plurality of lumens therein, each of the plurality of lumens extending through the insert. Each of the plurality of lumens are configured to receive oil from an oil pump.

[0004] According to a second set of embodiments, an engine system comprises a cylinder block, a cylinder head connected to the cylinder block, and an overhead structure connected to the cylinder head such that the cylinder head is positioned between the cylinder block and the overhead structure. The engine system further includes 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 includes an outer tube and an insert extending through the outer tube. The insert defines a plurality of lumens therein. Each of the plurality of lumens extend through the insert. Each of the plurality of lumens are configured to receive oil from an oil pump.

[0005] According to a third set of embodiments, a method of manufacturing a rocker shaft for oiling engine components comprises providing an outer tube and an insert. The method further includes placing the insert in the outer tube and aligning each of a plurality of lumens defined by the insert, and extending through the insert, with a plurality of outer oil holes formed in the outer tube.

[0006] This summary is illustrative only and is not intended to be in any way limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

[00071 The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures wherein like reference numerals refer to like elements, in which: [0008] FIG. 1 is a cross-sectional view of an engine system according to one embodiment, showing a position of a rocker shaft.

[0009] FIG. 2 is a perspective view of an overhead structure of the engine system of FIG. 1. showing a position of the rocker shaft of FIG. I. [0010] FIG. 3 is a perspective view of the rocker shaft of FIG. 1.

[00111 FIG. 4 is a transparent, perspective view of the rocker shaft of FIG. 1.

[0012] FIG. 5 is a flowchart of a method of manufacturing a rocker shaft for oiling engine components, according to an embodiment.

[0013] The foregoing and other features of the present disclosure will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

DETAILED DESCRIPTION

[0014] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and made part of this disclosure.

[0015] Implementations herein relate to a rocker shaft that includes an insert extending through an outer tube of the rocker shaft and a plurality of lumens extending through the outer tube of the rocker shaft. The insert may be, for example, extruded, injection molded, sintered, die cast, investment cast, or additively manufactured. The plurality of lumens are configured to receive oil from an oil pump and to allow oil to exit from the rocker shaft through a plurality of outer oil holes formed in the outer tube. In this way, the rocker shaft may provide benefits such as allowing for different configurations of lumens in rocker shafts for oiling engine components, allowing for multiple separate passageways for oil within a single rocker shaft, allowing for simplified manufacture without drilling of the rocker shaft, and allowing for lumens that extend through the full length of the rocker shaft.

[0016] FIG. 1 depicts an engine system 100, according to an example embodiment. The engine system 100 may be a diesel powered engine system 100, a spark-ignition engine system powered by gasoline, ethanol, or other fuel employed by spark-ignition engine systems, or other type of engine system. The engine system 100 may be on a passenger vehicle (e.g., sedan, van, pick-up truck, etc.), a commercial vehicle (e.g., semi-trailer truck, etc.), or on another system that employs an engine system 100 including stationary systems.

100171 The engine system 100 includes a cylinder block 110 (e.g., engine component, block, etc.). The cylinder block 110 includes a plurality of cylinders 112 positioned within the cylinder block 110. The cylinders 112 are configured to allow a plurality of pistons 114 to move within the cylinders 112. Each cylinder 112 may be configured to allow one or two pistons 114 to move within the cylinder 112. The cylinder block 110 may have one, two, three, four, five, six, or more cylinders 112. The cylinders 112 may be positioned in a single row or in multiple rows.

[0018] A cylinder head 120 (e.g., engine component, head, etc.) is connected to the cylinder block 110. The cylinder head 120 is configured to provide combustion chambers 121 that align with the cylinders 112 of the cylinder block 110. A channel 126 is formed in the cylinder head 120 to allow intake gases and exhaust gases to enter and exit the cylinder 112 and the combustion chamber 121 when the engine system 100 is operated.

[0019] FIG. 2 depicts an overhead structure 130 (e.g., engine component, etc.) that is connected to the cylinder head 120 such that the cylinder head 120 is positioned between the cylinder block 110 and the overhead structure 130, as shown in FIG. 1. In alternative arrangements, the overhead structure 130 is connected to the cylinder head 120 such that the cylinder head 120 is not positioned between the cylinder block 110 and the overhead structure 130.

[0020] A camshaft 138 (e.g., engine component, etc.) may be connected to the overhead structure 130. The camshaft 138 may have a plurality of cam lobes 139 positioned along the length of the camshaft 138.

[0021] As shown in FIGS. 1-2, a rocker shaft 200 (discussed in further detail herein) is connected to the overhead structure 130 using a fastener 132 (e.2., bolt, screw, etc.). In alternative arrangements, the rocker shaft 200 may be attached to another engine component of the engine system 100 and/or may be attached by other techniques. In some embodiments and as shown in FIGS. 1-2, the engine system 100 has one rocker shaft 200. In alternative arrangements, the engine system 100 may have one, two, three, four, or more rocker shafts 200.

[0022] As shown in FIGS. 1-2. a plurality of rocker arms 134 (e.g., engine components. etc.) is attached to the rocker shaft 200. In some embodiments and as shown in FIGS. 1-2, at least two rocker arms 134 are attached to the rocker shaft 200 for each cylinder 112 of the cylinder block 110. In alternative arrangements, at least one rocker arm 134 may be attached to the rocker shaft 200 for each cylinder 112 of the cylinder block 110.

[0023] Each of the plurality of rocker arms 134 has a first end 135 that is positioned above a cylinder 112 of the cylinder block 110. The first end 135 of each of the plurality of rocker arms 134 is connected to a valve stem 124 that is connected to a valve head 122 that is positioned above the cylinder 112.

[0024] Each of the plurality of rocker arms 134 has a second end 136. In some embodiments and as shown in FIG. 2, the second end 136 of each of the plurality of rocker arms 134 has a cam follower 137. The cam follower 137 is positioned such that when the camshaft 138 rotates, the cam lobe 139 of the camshaft 138 contacts the cam follower 137 and moves the second end 136 of the respective rocker arm 134. In alternative arrangements, a pushrod may be positioned between the cam lobe 139 of the camshaft 138 and the second end 136 of each of the plurality of rocker arms 134 such that the cam lobe 139 moves the pushrod, which moves the second end 136 of the respective rocker arm 134. Moving the second end 136 of each of the plurality of rocker arms 134 also moves the first end 135 of the respective rocker arm 134 so that the valve stem 124 moves the valve head 122, opening and closing the cylinder 112 to the channel 126 of the cylinder head 120.

[00251 FIG. 3 depicts a perspective view of a rocker shaft 200. FIG. 4 depicts a transparent, perspective view of the rocker shaft 200. The rocker shaft 200 may be used in the engine system 100 of FIG. 1. In some embodiments and as shown in FIGS. 1-2, the rocker shaft 200 is attached to the overhead structure 130. In alternative arrangements, the rocker shaft 200 may be attached to another engine component.

[00261 The rocker shaft 200 includes an outer tube 202 (e.g., shaft, pipe, duct, cylinder, etc.). In some embodiments and as shown in FIGS. 1-4, the outer tube 202 has a circular cross-sectional shape. In alternative arrangements, the outer tube 202 may have a cross-sectional shape that is a circle, a circular segment, a circular sector, an oval, a polygon, rounded polygon, or other geometric shape. In some example implementations, the outer tube 202 may have a cross-sectional width (e.g., a diameter where the cross-sectional shape is circular) that is approximately in a range of 1-10 cm. As used herein, a range of X to Y includes X, Y, and values between X and Y. The outer tube 202 may have a length that is approximately equal to the length of the overhead structure 130 or the engine system 100. In some example implementations, the outer tube 202 may have a length that is approximately in a range of 5300 cm. In some example implementations, the wall of the outer tube 202 may have a width that is approximately in a range of 0.5-5 mm. In some example implementations, the outer tube 202 comprises steel, which allows for withstanding the loads place on the outer tube 202 by the operation of the engine system 100.

[0027] An insert 204 (e.g., core, interior, etc.) extends through the outer tube 202. An outer surface of the insert 204 contacts the inner surface of the outer tube 202. The insert 204 may have a length that is equal to or greater than the length of the outer tube 202. The insert 204 may have a cross-sectional shape that is a circle, a circular segment, a circular sector, an oval, a polygon, rounded polygon, or other geometric shape. In some example implementations, the insert 204 may have a cross-sectional width (e.g., a diameter where the cross-sectional shape is circular) that is approximately in a range of 0.5-9.5 cm.

[0028] ffi some example implementations, the insert 204 may comprise a material selected from the group consisting of aluminum, steel, ceramic, a polyamide, a polymer, and a polymer composite. Other materials may be used as well. In some example implementations, the insert 204 may be manufactured by extrusion, by injection molding, by sintering, by die cast, by investment cast, by additive manufacturing, or by other manufacturing techniques. In some example implementations, the insert 204 may comprise sintered steel, sintered ceramic, an injection molded polyamide, an injection molded polymer, an injection molded polymer composite, an extruded polyamide, an extruded polymer, an extruded polymer composite, extruded aluminum, or die cast aluminum.

[0029] In some embodiments and as shown in FIGS. 3-4, the outer tube 202 defines an outer recessed groove 212 (e.g., cut, furrow, indentation, etc.) formed therein and the insert 204 defines an inner recessed groove 213 (e.g., cut, furrow, indentation, etc.) formed therein. In alternative arrangements, the outer tube 202 does not have an outer recessed groove 212 and/or the insert 204 does not have an inner recessed groove 213. In alternative arrangements, the outer tube 202 may have one, two, three, four, five, six, seven or more outer recessed grooves 212, and/or the insert 204 may have one, two, three, four, five, six, seven or more inner recessed grooves 213. The outer recessed groove 212 and the inner recessed groove 213 allow the rocker shaft 200 to be attached to an engine component of the engine system 100 such as the overhead structure 130. In some embodiments and as shown in FIGS. 3-4, the outer recessed groove 212 and the inner recessed groove 213 each have a cross-sectional shape that is a circular segment. In alternative arrangements, the outer recessed groove 212 and/or the inner recessed groove 213 may each have a cross-sectional shape that is a circular segment, a circular sector, a polygon, rounded polygon, or other geometric shape. In some embodiments, each of the outer recessed grooves 212 has the same cross-sectional shape and each of the inner recessed grooves 213 has the same cross-sectional shape. In other embodiments, at least one of the outer recessed grooves 212 may have a cross-sectional shape that. is different from that of another of the outer recessed grooves 212, and/or at least one of the inner recessed grooves 213 may have a cross-sectional shape that is different from that of another of the inner recessed grooves 213.

[0030] The insert 204 defines a plurality of lumens 206, 208, and 210 (e.g., galleries, channels, cavity, space, etc.). Each of the plurality of lumens 206, 208, and 210 extends through the insert 204. In some embodiments, at least one of the plurality of lumens 206, 208, and 210 is formed between the outer tube 202 and the insert 204. In other embodiments, at least one of the plurality of lumens 206, 208, and 210 is formed in the insert 204. In some embodiments and as shown in FIGS. 1-4, the first lumen 206 is formed in the insert 204 and the second lumen 208 and third lumen 210 are formed between the outer tube 202 and the insert 204.

[0031] Each of the plurality of lumens 206, 208, and 210 is configured to receive oil from an oil pump (not shown). In some embodiments, each of the plurality of lumens 206, 208, and 210 is configured to receive the same oil from the same oil pump. In other embodiments, at least one of the plurality of lumens 206, 208, and 210 is configured to receive a different oil from a different oil pump than is another of the plurality of lumens 206, 208, and 210.

[0032] In some embodiments and as shown in FIGS. 1-4, the plurality of lumens 206, 208, and 210 of the rocker shaft 200 includes three lumens 206, 208, and 210. In alternative arrangements, the plurality of lumens 206, 208, and 210 may include one, two, three, four, more lumens.

[0033] Each of the plurality of lumens 206, 208, and 210 may have a length that is equal to the length of the outer tube 202. When the insert 204 is manufactured using injection molding, sinterin2, die cast, investment cast, or additive manufacturing techniques, at least one of the plurality of lumens 206, 208, and 210 may have a length that is less than the length of the outer tube 202.

[0034] The plurality of lumens 206, 208, and 210 may have a cross-sectional shape that is a circle, a circular segment, a circular sector, an oval, a polygon, rounded polygon, or other geometric shape. At least one of the plurality of lumens 206, 208, and 210 may have a cross-sectional shape that is different from that of another of the plurality of lumens 206, 208 and 210. In some embodiments and as shown in FIGS. 1-4, the first lumen 206 has a cross-sectional shape that is a circle, the second lumen 208 has a cross-sectional shape that is approximately a rounded pentagon, and the third lumen 210 has a cross-sectional shape that is approximately a rounded triangle. When the insert 204 is manufactured using injection molding, sintering, die cast, investment cast, or additive manufacturing techniques, at least one of the plurality of lumens 206, 208, and 210 may have a cross-sectional shape that varies over the length of the at least one of the plurality of lumens 206, 208, and 210.

[0035] In some example implementations, each of the plurality of lumens 206, 208, and 210 may have a cross-sectional width (e.g., a diameter where the cross-sectional shape is circular) that is approximately in a range of 2-20 mm. At least one of the plurality of lumens 206, 208, and 210 may have a cross-sectional width that is different from that of another of the plurality of lumens 206, 208, and 210. When the insert 204 is manufactured using injection molding, sintering, die cast, investment cast, or additive manufacturing techniques, at least one of the plurality of lumens 206, 208, and 210 may have a cross-sectional width that varies over the length of the at least one of the plurality of lumens 206, 208, and 210.

[00361 In some embodiments and as shown in FIGS. 1-4, the plurality of lumens 206, 208, and 210 are positioned in the rocker shaft 200 so that the first lumen 206 is located to the left of the second lumen 208 and the third lumen 210 is located to the right of the second lumen 208. In alternative arrangements, the plurality of lumens 206, 208, and 210 may be positioned at other locations of the rocker shaft 200 and with different relative positioning to each other, as compared to the arrangement of the plurality of lumens 206, 208, and 210 of FIGS. 1-4.

[0037] In some embodiments and as shown in FIGS. 3-4, each of the plurality of lumens 206, 208, and 210 defines a straight pathway in the rocker shaft 200. In alternative arrangements and when the insert 204 is manufactured using injection molding, sintering, die cast, investment cast, or additive manufacturing techniques, at least one of the plurality of lumens 206, 208, and 210 may define a pathway that has bends. When at least one of the plurality of lumens 206, 208, and 210 defines a pathway that has bends, the pathway of at least one of the plurality of lumens 206, 208, and 210 may be positioned so that the at least one of the plurality of lumens 206, 208, and 210 is routed around an inner fastener hole 215 of the rocker shaft 200 or around another feature of die rocker shaft 200. When at least one of the plurality of lumens 206, 208, and 210 defines a pathway that has bends, the pathway of the at least one of the plurality of lumens 206. 208, and 210 may have one, two, three, four, or more bends. In some example implementations, when at least one of the plurality of lumens 206, 208, and 210 defines a pathway that has bends, each of the bends may have an angle that is in a range of 0-180 degrees. When at least one of the plurality of lumens 206, 208, and 210 defines a pathway that has bends, each of the bends may be formed as corners or as rounded segments. When at least one of the plurality of lumens 206, 208, and 210 defines a pathway that has bends, each of the bends may be formed in any radial direction of the rocker shaft 200.

[0038] The outer tube 202 defines a plurality of outer oil holes 216, 218, and 220 (e.g., opening, gap, etc.) formed therein. The plurality of outer oil holes 216, 218, and 220 are connected to the plurality of lumens 206, 208, and 210 so that oil received by the plurality of lumens 206, 208, and 210 may exit the outer tube 202 through the plurality of outer oil holes 216, 218, and 220. When an engine component such as one of the plurality of rocker arms 134 of the engine system 100 is attached to the rocker shaft 200, the oil of the rocker shaft 200 may exit the rocker shaft 200 through the plurality of outer oil holes 216, 218, and 220 and enter an engine component such as the rocker arm 134.

[0039] When at least one of the plurality of lumens 206, 208, and 210 is formed in the insert 204, the insert 204 defines a plurality of inner oil holes 217 and 219 formed therein, allowing the oil from the at least one of the plurality of lumens 206, 208, and 210 formed in the insert 204 to exit the insert 204, as shown in FIG. 4 by the first lumen 206 and the inner oil holes 217 and 219. in some embodiments and as shown in FIG. 4, the number of inner oil holes 217 and 219 may differ from the number of outer oil holes 216, 218, and 220. In alternative arrangements, the number of inner oil holes 217 and 219 may be the same as the number of outer oil holes 216, 218, and 220. As shown in FIG. 4, the plurality of inner oil holes 217 and 219 are positioned along the insert 204 at axial locations of the rocker shaft 200 that align with the positioning of at least some of the plurality of outer oil holes 216, 218, and 220 along the outer tube 202.

[0040] In some embodiments and as shown in FIGS. 3-4, each of the plurality of outer oil holes 216, 218, and 220 and each of the plurality of inner oil holes 217 and 219 have a circular shape. In alternative arrangements, at least one of the plurality of outer oil holes 216. 218, and 220 and/or at least one of the plurality of inner oil holes 217 and 219 may have a shape that is a circle, a circular segment, a circular sector, an oval, a polygon, rounded polygon, or other geometric shape. In some embodiments, each of the plurality of outer oil holes 216, 218, and 220 and each of the plurality of inner oil boles 217 and 219 may have the same shape. In other embodiments, at least one of the plurality of outer oil holes 216, 218, and 220 may have a shape that is different from that of another of the plurality of outer oil holes 216, 218, and 220, and/or at least one of the plurality of inner oil holes 217 and 219 may have a shape that is different from that of another of the plurality of inner oil holes 217 and 219. In some example implementations, each of the plurality of outer oil holes 216, 218, and 220 and each of the plurality of inner oil holes 217 and 219 may have a width (e.g., a diameter where the shape is circular) that is approximately in a range of 2-15 mm At least one of the plurality of outer oil holes 216, 218. and 220 may have a width that is different from that of another of the plurality of outer oil holes 216, 218, and 220, and/or at least one of the plurality of inner oil holes 217 and 219 may have a width that is different from that of another of the plurality of inner oil holes 217 and 219. In some embodiments, each of the plurality of outer oil holes 216. 218. and 220 and each of the plurality of inner oil holes 217 and 219 have a width that is constant. In other embodiments, at least one of the plurality of outer oil holes 216, 218, and 220 may have a width that varies over the pathway defined by the hole in the outer tube 202, and/or at least one of the plurality of inner oil holes 217 and 219 may have a width that varies over the pathway defined by the hole in the insert 204.

[0041] In some embodiments and as shown in FIGS. 3-4, the plurality of outer oil holes 216, 218, and 220 are positioned along the outer tube 202 with equal spacing between each of the plurality of outer oil holes 216, 218, and 200, and the plurality of inner oil holes 217 and 219 are positioned along the insert 204 with equal spacing between each of the plurality of inner oil holes 217 and 219. In alternative arrangements, the plurality of outer oil holes 216, 218, and 220 may be positioned along the outer tube 202 with different spacing between at least some of the plurality of outer oil holes 216, 218, and 220, and/or the plurality of inner oil holes 217 and 219 may be positioned along the insert 204 with different spacing between at least some of the plurality of inner oil holes 217 and 219. In some embodiments and as shown in FIGS. 3-4, the plurality of outer oil holes 216, 218, and 220 are positioned linearly along the outer tube 202 and the plurality of inner oil holes 217 and 219 are positioned linearly along the insert 204. In alternative arrangements, at least one of the plurality of outer oil holes 216, 218, and 220 may be positioned at a different radial position of the outer tube 202 than is another of the plurality of outer oil holes 216, 218, and 220 such that the plurality of outer oil holes 216, 218, and 220 are not positioned in a line along the outer tube 202, and/or at least one of the plurality of inner oil holes 217 and 219 may be positioned at a different radial position of the insert 204 than is another of the plurality of inner oil holes 217 and 219 such that the plurality of inner oil holes 217 and 219 are not positioned in a line along the insert 204.

[0042] In some embodiments, an end of the rocker shaft 200 may have a cap (not shown) to block the flow of oil out of the end of the rocker shaft 200. When the insert 204 is manufactured using injection molding, sintering, die cast, investment cast, or additive manufacturing techniques, the cap may be formed as a part of the insert 204. When the insert 204 is manufactured using an extrusion technique, the cap may be a separate part from the insert 204.

[0043] In some embodiments, the outer tube 202 defines a plurality of outer fastener holes 214 (e.g., opening, gap, etc.) formed therein, and the insert 204 defines a plurality of inner fastener holes 215 (e.g.. opening, gap, etc.) formed therein. Each of the plurality of outer fastener holes 214 and each of the plurality of inner fastener holes 215 are configured to receive a fastener 132 for securing the rocker shaft 200 to an engine component such as the overhead structure 130. When the fastener 132 passes through at least one of the plurality of lumens 206, 208, and 210, the at least one of the plurality of lumens 206, 208, and 210 is wider than the fastener 132 such that the oil in the at least one of the plurality of lumens 206, 208, and 210 may pass around the fastener 132, as shown in FIGS. 3-4 by the second lumen 208. In some embodiments and as shown in FIGS. 2-4, the plurality of outer fastener holes 214 are positioned along the outer tube 202 with equal spacing between each of the plurality of outer fastener holes 214 and the plurality of inner fastener holes 215 are positioned along the insert 204 with equal spacing between each of the plurality of inner fastener holes 215. In alternative arrangements, the plurality of outer fastener holes 214 may be positioned along the outer tube 202 with different spacing between at least some of the plurality of outer fastener holes 214, and/or the plurality of inner fastener holes 215 may be positioned along the insert 204 with different spacing between at least some of the plurality of inner fastener holes 215.

[0044] In some embodiments and as shown in FIGS. 3-4, each of the plurality of outer fastener holes 214 and each of the plurality of inner fastener holes 215 have a circular shape. In alternative arrangements, at least one of the plurality of outer fastener holes 214 and/or at least one of the plurality of inner fastener holes 215 may have a shape that is a circle, a circular segment, a circular sector, an oval, a polygon, rounded polygon, or other geometric shape. In sonic embodiments, each of the plurality of outer fastener holes 214 and each of the plurality of inner fastener holes 215 may have the same shape. In other embodiments, at least one of the plurality of outer fastener holes 214 may have a shape that is different from that of another of the plurality of outer fastener holes 214, and/or at least one of the plurality of inner fastener holes 215 may have a shape that is different from that of another of the plurality of inner fastener holes 215. In some example implementations, each of the plurality of outer fastener holes 214 and each of the plurality of inner fastener holes 215 may have a width (e.g., a diameter where the shape is circular) that is approximately in a range of 7-24 mm. In some embodiments, each of the plurality of outer fastener holes 214 and each of the plurality of inner fastener holes 215 has the same width. In other embodiments, at least one of the plurality of outer fastener holes 214 may have a width that is different from that of another of the plurality of outer fastener holes 214, and/or at least one of the plurality of inner fastener holes 215 may have a width that is different from that of another of the plurality of inner fastener holes 215.

[0045] In some embodiments, a plug 222 may be positioned in at least one of the plurality of lumens 206, 208, and 210. In some embodiments and as shown in FIG. 4, the plug 222 is a ball. In alternative arrangements, the plug 222 may have a shape that is a cylindrical plug, cup plug, or other geometric shape. The plug 222 may have a width equal to the width of the at least one of the plurality of lumens 206, 208, and 210 that the plug 222 is positioned in. In some example implementations, the plug 222 may comprise steel. In FIG. 4, the plug 222 is positioned in the first lumen 206. The plug 222 is configured to allow separate oil signal pulses to be provided to a portion of the rocker shaft 200 corresponding to individual cylinders 112 using the one of the plurality of lumens 206, 208, and 210 that the plug 222 is positioned in. The oil signal pulses may be used for cylinder deactivation (CDA), variable valve timing, or variable valve lift, among other variable valve actuation operations. In CDA, at least one of the cylinders 112 of the engine system 100 is not operated (e.g., is deactivated) while at least another of the cylinders 112 of the engine system 100 does operate (e.g., is activated). The cylinder 112 may be configured to be deactivated when one of the plurality of rocker arms 134, which is configured to move the valve head 122 above the cylinder 112, receives oil from the rocker shaft 200, and may be configured to be activated when the respective rocker arm 134 does not receive oil from the rocker shaft 200. The plug 222 may be positioned in the at least one of the plurality of lumens 206, 208, and 210 such that when the at least one of the plurality of lumens 206, 208, and 210 receives oil, that a chosen number of rocker arms 134 may receive oil and a chosen number of rocker arms 134 do not receive oil, resulting in a chosen number of cylinders 112 being deactivated and a chosen number of cylinders 112 remaining activated. When the insert 204 is manufactured using an injection molding, sintering, die cast, investment cast, or additive manufacturing technique, a portion of the insert 204. instead of or in addition to a plug 222, may be formed to prevent oil flow to a portion of the rocker shaft 200 and may be used for CDA in the same way as the plug 222.

[0046] FIG. 5 depicts a flowchart of a method 300 (e.2., process, procedure, etc.) for manufacturing a rocker shaft 200 for oiling engine components. The rocker shaft 200 may be used in an engine system such as the engine system 100.

[0047] The method 300 includes at 302 providing an outer tube 202 and an insert 204. The insert 204 may be manufactured using extrusion, injection molding, sintering, die cast, investment cast, or additive manufacturing techniques. At 304, the insert 204 is placed in the outer tube 202, for example in a press fit arrangement. At 306, each of a plurality of lumens 206, 208, and 210 defined by the insert 204 and extending through the insert 204 are aligned with a plurality of outer oil holes 216, 218, and 220 defined by the outer tube 202. Each of the plurality of lumens 206, 208, and 210 are configured to receive oil from an oil pump. Each of the plurality of outer oil holes 216, 218, and 220 allow the oil from the plurality of lumens 206, 208, and 210 to exit the outer tube 202.

100481 While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed but rather as descriptions of features specific to particular implementations. Certain features described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can, in some cases, be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[00491 As utilized herein, the terms "substantially," "generally," "approximately," and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the appended claims.

[0050] The term coupled" and the like, as used herein, mean the joining of two components directly or indirectly to one another. Such joining may he stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two components or the two components and any additional intermediate components being integrally formed as a single unitary body with one another, with the two components, or with the two components and any additional intermediate components being attached to one another.

[0051] It is important to note that the construction and arrangement of the various systems shown in the various example implementations is illustrative only and not restrictive in character. All changes and modifications that come within the spirit and/or scope of the described implementations are desired to be protected. It should be understood that some features may not be necessary, and implementations lacking the various features may be contemplated as within the scope of the disclosure, the scope being defined by the claims that follow. When the language -a portion" is used, the item can include a portion and/or the entire item unless specifically stated to the contrary.

[0052] References herein to the positions of elements (e.g., "top," "bottom," "above," "below," "left," "right") are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other example embodiments and that such variations arc intended to he encompassed by the present disclosure.

[0053] Also, the term "or" is used, in the context of a list of elements, in its inclusive sense (and not in its exclusive sense) so that when used to connect a list of elements, the term "of' means one, some, or all of the elements in the list. Conjunctive language such as the phrase "at least one of X. Y, and Z," unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y. Z, X and Y, X and Z. Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z). Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y. and at least one of Z to each be present, unless otherwise indicated.

Claims

WHAT IS CLAIMED 15: 1. A rocker shaft for oiling engine components, comprising: an outer tube; an insert extending through the outer tube, the insert defining a plurality of lumens 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 or claim 2, 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 any preceding claim, wherein at least one of the plurality of lumens is formed between the insert and the outer tube.
5. The rocker shaft of any preceding claim, 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 any preceding claim, wherein each of the plurality of lumens has a same cross-sectional shape.
8. The rocker shaft of any preceding claim, 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 any preceding claim, wherein at least one of the plurality of lumens extends through the length of the outer tube.
10. The rocker shaft of any preceding claim, 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. The rocker shaft of any preceding claim, wherein the outer tube defines a plurality of outer fastener holes formed therein and the insert defines a plurality of inner fastener holes formed therein, each of the plurality of outer fastener holes and each of the plurality of inner fastener holes configured to receive a fastener for securing the rocker shaft to an engine component.
12. The rocker shaft of any preceding claim, 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; and an insert extending through the outer tube, the insert defining a plurality of lumens 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 or claim 14, 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 claims 13 to 15, 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 claims 13 to 16, 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 claims 13 to 18, wherein each of the plurality of lumens has a same cross-sectional shape.
20. The engine system of any of claims 13 to 19, 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 claims 13 to 20, wherein at least one of the plurality of lumens extends through the length of the outer tube.
22. The engine system of any of claims 13 tp 21, 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. The engine system of any of claims 13 to 22, wherein the outer tube defines a plurality of outer fastener holes formed therein and the insert defines a plurality a plurality of inner fastener holes formed therein, each of the plurality of outer fastener holes and each of the plurality of inner fastener holes configured to receive a fastener for securing the rocker shaft to the overhead structure.
24. The engine system of any of claims 13 to 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 and an insert; placing the insert in the outer tube; and aligning each of a plurality of lumens defined by the insert and extending through the insert with a plurality of outer oil holes defined by the outer tube.
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 or claim 26, 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.COC 1.0 icr (.1