Perkins Engines Company Limited

Caterpillar Inc.

Frank George Hughes

Richard Jackson

Howard J Paul

Kathleen Bernadette Queenan

John Robert Sherwood

Use of rocker shaft pedestals that are manufactured separately from the cylinder head and subsequently fixed to the cylinder head increases manufacturing and assembly costs of an internal combustion engine. The disclosed cylinder head obviates these problems by providing a cylinder head for an internal combustion engine that comprises a top deck and at least one integrally cast rocker shaft pedestal. A rocker shaft for use with a cylinder head of the invention includes at least one flat formed on an underside of the shaft that is adapted for mating with a top of a rocker shaft pedestal. Also described is an internal combustion engine comprising a cylinder block, a cylinder head having a top deck and at least one integrally cast rocker shaft pedestal, and a rocker shaft mounted on the at least one rocker shaft pedestal, the rocker shaft having a plurality of rocker arms mounted thereon. The rocker shaft includes at least one flat formed on an underside thereof adapted for mating with a top of the at least one rocker shaft pedestal. Also described is a method for manufacturing a cylinder head assembly including an integrally cast rocker shaft pedestal.

Cylinder head having an integrally cast rocker shaft pedestal

To prevent seal failure in internal combustion engines, blow-by gasses leaking past the piston rings require venting. However, moving engine components cause airborne oil particles to be mixed in with the gasses. Depending on breather system and engine type, oil carry-over can cause increased operating costs, reduced engine performance and emissions issues. The present invention provides a simple and inexpensive barrier device fitted in a cylinder block. The device is positioned such that oil particles impact on the device and coagulate to form droplets which subsequently run back to the crankcase. Some advantages provided by the present invention are that the engine envelope is unaffected, the barrier device is the only additional part, and the cylinder block requires no or minimal adaptation.

Internal combustion engine having an internal barrier device to reduce oil carry-over

Increasing the diameter of cylinder bores in a cylinder block requires a longer and heavier cylinder block to accommodate the larger bores. If the cylinder block is not lengthened it is difficult to accommodate the water jacket between the outermost cylinder bore and the cylinder block end wall. The cylinder block of the present invention has an upper part including a number of cylinder bores surrounded by a water jacket. The upper part also has first and second end walls which are generally co-planar with first and second end walls of a lower part of the block, but include projecting portions adjacent the top deck. The projecting portions may curve outwardly from the first and second end walls and generally follow the curvature of the two outermost cylinder bores on the block. By providing the projecting portions on the first and second end walls, a minimum width of water jacket can be accommodated without significantly increasing the length and overall size of the block.

Cylinder block for an internal combustion engine having a locally thickened end wall

A cylinder block has a number of cylinder bores and a water jacket at least partially surrounding the bores. When casting a cylinder block the water jacket is formed by a slender wall of a sand core. To enable the wall to be removed from the core box the wall must taper over its entire height. Prior art water jackets therefore taper from a minimum sand core wall width at the base to a large width at the top. The cylinder block of the invention has a water jacket which, when viewed in transverse section, is wider in an intermediate portion than at either its top or base. In providing a water jacket which is narrower at the top, there is more room for the addition of machined features on the top deck. Furthermore, a water jacket which is narrower at the base can have a greater depth than conventional water jackets.

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Lincolnshire, United Kingdom

Frank George Hughes