Rocker arm shaft retainer and assembly

A rocker arm shaft retainer includes an elongated contoured sheet-like body having two opposite ends, two opposite sides longer in length than the ends, and a central portion between the sides. A plurality of fingers extend from the central portion towards the sides and each finger has a contoured recess for engaging a rocker shaft. The fingers define slots for receiving rocker arms. The retainer further includes a plurality of thrust faces along edges of the fingers for axial positioning of rocker arms on a rocker shaft. A plurality of bosses are also disposed on the fingers, each of the bosses having a generally flat surface.

TECHNICAL FIELD

This invention relates to internal combustion engines, and more particularly to internal combustion engines utilizing rocker arm and shaft-type valvetrains.

BACKGROUND OF THE INVENTION

It is known in the art relating to internal combustion engines to utilize rocker arm and shaft-type valvetrains. In this type of valvetrain, it is necessary to retain the rocker arm shafts and properly space the rocker arms on the rocker shafts. Several different conventional methods exist to retain the rocker shafts and to maintain rocker spacing. These include using clamping blocks to retain the rocker shafts and spacers to axially position the rocker arms. Other systems use springs to thrust the rocker arms against a machined face on the cylinder head or some secondary casting thereof.

These conventional systems require the use of a multitude of parts for the retention of the rocker arm shafts and the axial positioning of the rocker arms. Further, conventional systems also require additional machining of parts. Machining and the need for multiple parts increases the cost of positioning and retaining the rocker arms and rocker arm shafts and of assembling these components into an engine.

SUMMARY OF THE INVENTION

The present invention provides a rocker arm shaft retainer for the retention of engine rocker arm shafts of an internal combustion engine to an engine cylinder head or a subassembly thereof. The rocker arm shaft retainer also provides for axial positioning of the engine rocker arms on the shafts.

In an exemplary embodiment, a rocker arm shaft and rocker arm assembly in accordance with the present invention includes a lifter oil manifold that carries hydraulic valve lifters and cylinder deactivation components. The lifter oil manifold also includes at least one mounting and a lifter oil feed pipe mounted to the mounting. The assembly further includes two rocker arm shafts and a plurality of rocker arms disposed on each of the rocker arm shafts. Fasteners fasten the rocker arm shaft retainer to the rocker arm shafts and fasten the rocker arm shafts to the lifter oil manifold, thereby retaining the rocker arm shafts in the assembly.

The assembly may include twelve rocker arms. Four of the rocker arms may be disposed on one rocker arm shaft and eight of the rocker arms may be disposed on the other rocker arm shaft offset longitudinally from each of the four rocker arms. The four rocker arms may be exhaust rockers and the eight rocker arms may be intake rockers. The lifter oil feed pipe may be spacedly mounted to the lifter oil manifold, the lifter oil feed pipe being disposed above the retainer.

The rocker arm shaft retainer itself includes an elongated contoured sheet-like body having two opposite ends, two opposite sides longer in length than the ends, and a central portion between the sides. A plurality of fingers extend from the central portion to the sides. Each finger has a contoured recess for engaging one of the rocker arm shafts. The fingers define slots for receiving the rocker arms. A plurality of thrust faces along edges of the fingers provide for axial positioning of the rocker arms on the rocker shafts. A plurality of bosses are disposed on the fingers. Each of the bosses has a generally flat surface.

The central portion of the retainer may include at least one opening therein. At least one finger may include more than one boss. Each boss may include an aperture therethrough. The slots formed along one side of the sheet-like body may be offset longitudinally from the slots formed along the opposite side of the sheet-like body. The retainer may include fourteen fingers and twelve slots. Eight of the slots may be formed along one side of the sheet-like body and four of the slots may be formed along the opposite side of the sheet-like body offset from each of the eight slots. Further, the sheet-like body may have a curvilinear cross-section.

In the rocker arm shaft and rocker arm assembly, the at least one mounting for the lifter oil feed pipe may extend through one of the openings in the central portion of the retainer. Each of the rocker arm shafts includes apertures therethrough correspondingly disposed in relation to the apertures of the bosses along one of the sides of the sheet-like body. The rocker arm shaft retainer mates with the rocker arm shafts along the recesses of the fingers. The rocker arms are received in the slots of the retainer, the apertures of the rocker arm shafts are aligned with the apertures of the bosses, and each of the fasteners is inserted through one of the apertures of the bosses and corresponding apertures of the rocker arm shafts, thereby positioning the rocker arms along each of the rocker arm shafts.

These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings in detail, numeral10generally indicates a rocker arm shaft and rocker arm assembly for use in an internal combustion engine. The assembly10includes a rocker arm shaft retainer12in accordance with the present invention. The rocker arm shaft retainer12is a single member design that provides for the retention of engine rocker arm shafts and for the axial positioning of engine rocker arms on the rocker arm shafts.

With reference toFIGS. 1 through 3, the rocker arm shaft and rocker arm assembly10includes a lifter oil manifold14that carries hydraulic valve lifters and cylinder deactivation components (not shown). The lifter oil manifold14also includes at least one mounting16and a lifter oil feed pipe18mounted to the mounting16. The assembly10further includes two rocker arm shafts20,22and a plurality of rocker arms24disposed on each of the rocker arm shafts20,22. Fasteners26fasten the rocker arm shaft retainer12to the rocker arm shafts20,22and the rocker arm shafts20,22to the lifter oil manifold14, thereby retaining the rocker arm shafts20,22in the assembly10.

In the embodiment shown in the drawings, the assembly10is adapted for use with a V8 internal combustion engine having three valves per cylinder, two of which are intake valves and one of which is an exhaust valve. The assembly10and the corresponding rocker arm shaft retainer12, may, however, be adapted for use with a variety of rocker arm and shaft type internal combustion engine valvetrains. The use of the assembly10simplifies the installation of the components of the assembly10into an internal combustion engine.

In this arrangement, the assembly10may include twelve rocker arms24. Four of the rocker arms24may be disposed on one rocker arm shaft20and eight of the rocker arms24may be disposed on the other rocker arm shaft22offset longitudinally from each of the four rocker arms24. The four rocker arms24may be exhaust rockers and the eight rocker arms24may be intake rockers. The lifter oil feed pipe18may be spacedly mounted to the lifter oil manifold14, the lifter oil feed pipe18being disposed above the retainer12.

Turning now toFIG. 4, the rocker arm shaft retainer12includes an elongated contoured sheet-like body having two opposite ends30,32, two opposite sides34,36longer in length than the ends30,32, and a central portion38between the sides34,36. A plurality of fingers40extend from the central portion38to the sides34,36. Each finger40has a contoured recess42for engaging one of the rocker arm shafts20,22. The fingers40define slots44for receiving the rocker arms24. A plurality of thrust faces46along edges48of the fingers40provide for axial positioning of the rocker arms24on the rocker shafts20,22by engaging edges27,28of a pivot29of each rocker arm24. A plurality of bosses50are disposed on the fingers40. Each of the bosses50has a generally flat surface52.

In an exemplary embodiment, the central portion38may include at least one opening54therein. At least one finger40may include more than one boss50. Each boss50may include an aperture56therethrough. The slots44formed along one side34of the sheet-like body may be offset longitudinally from the slots44formed along the opposite side36of the sheet-like body. The retainer12may include fourteen fingers40and twelve slots44. Eight of the slots44may be formed along one side34of the sheet-like body and four of the slots44may be formed along the opposite side36of the sheet-like body offset longitudinally from each of the eight slots. Further, the sheet-like body may have a curvilinear cross-section.

Returning to the rocker arm shaft and rocker arm assembly, the at least one mounting16for the lifter oil feed pipe18may extend through one of the openings54in the central portion38of the retainer12. Each of the rocker arm shafts20,22includes apertures58therethrough correspondingly disposed in relation to the apertures56of the bosses50along one of the sides34,36of the sheet-like body. The rocker arm shaft retainer12mates with the rocker arm shafts20,22along the recesses42of the fingers40. The rocker arms24are received in the slots44of the retainer12, the apertures58of the rocker arm shafts20,22are aligned with the apertures56of the bosses40, and each of the fasteners26is inserted through one of the apertures56of the bosses40and corresponding apertures58of the rocker arm shafts20,22, thereby positioning the rocker arms24along each of the rocker arm shafts20,22.

The rocker arm shaft retainer12of the present invention reduces the number of members needed to retain the rocker arm shafts20,22from, for example, a dozen or more down to one member. The reduction of the number of members reduces the cost of retaining the rocker arm shafts20,22while also simplifying assembly of the engine. The reduction of the number of members per engine subassembly, as well as the ability to align the rocker arms24within that subassembly, aids in the installation of the subassembly to an engine. The rocker arm shaft retainer12also acts as an error-proofing device by eliminating the possibility of mixing differently sized rocker arm spacers used in conventional rocker arm shaft and rocker arm assemblies.