Camshaft bearing arrangement for overhead cam engine
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorMasaaki Yoshikawa
Life of this patent
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Abstract
An arrangement for rotatably supporting first and second camshafts associated with first and second series of plural valves for the combustion chamber of an internal combustion engine. A cylinder head is affixed to the cylinder block by fastening means that are equally spaced with respect to the cylinder bores while the camshafts are offset at different distances from the cylinder bore axis on opposite sides of the cylinder head. The fastening arrangement includes cam carriers and bearing caps that support the respective camshafts and which are spaced so as to avoid interference with each other and to provide uniform tightening loads.
Claims20
In an assembly for an internal combustion engine comprising a cylinder block, a cylinder head detachably affixed to said cylinder block by a plurality of threaded fastening means, a plurality of poppet valves supported for reciprocation in said cylinder head, and a camshaft for operating said poppet valves, the improvement comprising a cam carrier detachably affixed to said cylinder head and overlying said threaded fastening means, and a bearing cap affixed to said cam carrier, said cam carrier and said bearing cap having bearing surfaces for journaling said camshaft.
In an assembly for an internal combustion engine comprising a cylinder block, a cylinder head detachably affixed to said cylinder block by a plurality of first threaded fastening means, a plurality of poppet valves supported for reciprocation by said cylinder head, and a cam shaft for operating said poppet valves, the improvement comprising a cam carrier detachably affixed by second threaded fastening means to said cylinder head and a bearing cap detachably affixed to said cam carrier by third threaded fastening means, said cam carrier and said bearing cap having bearing surfaces for journaling said camshaft.
An internal combustion engine comprising a cylinder block, a cylinder head detachably affixed to said cylinder block by a plurality of threaded fastening means, a first set of poppet valves supported for reciprocation by said cylinder head on one side of a plane containing the cylinder bore axis, a second set of poppet valves supported for reciprocation on the opposite side of said plane, first and second spaced camshafts each associated with a respective one of said sets of poppet valves for operating said respective poppet valves, a cam carrier detachably affixed to said cylinder head, a first series of bearing caps affixed to said cam carrier and journaling said first camshaft for rotation about a rotational axis offset from said plane by a first distance, and a second series of bearing caps detachably affixed to said cam carrier and journaling said second camshaft for rotation about a rotational axis that is offset from said plane by a different distance than the distance of offset of said first camshaft rotational axis and on the other side of said plane.
Dependencies are inferred from the claim text.