Structure of cylinder head assembly

A cylinder head assembly comprising:

• a cylinder head including first and second lower journal portions of respective first and second camshaft journals which are disposed in a laterally spaced relation and open upwardly from an upward facing head surface of said cylinder head for rotatably receiving and supporting respective first and second camshafts, and a head oil passageway, which extends longitudinally through said cylinder head for guiding oil therein, said cylinder head including at least first and second hydraulic adjuster guide chambers for slidably receiving corresponding hydraulic adjuster units therein so as to each be operatively engaged with a cam fixed respectively on each of said first and second camshafts, and first and second adjuster passageways each having a first end connected to said head oil passageway in communication therewith and a second end in communication with respective ones of said first and second hydraulic adjuster guide chambers;
• and
• a camshaft housing mounted to said upward facing head surface and including first and second upper journal portions of said first and second camshaft journals respectively, said upper journal portions opening downwardly and cooperating respectively with said lower journal portions so as to rotatably retain said camshafts respectively therein, said camshaft housing including an oil reserve chamber disposed centrally therein in communication with a source of lubrication oil, said oil reserve chamber having a lower chamber portion which includes an opening in communication with said head oil passageway for the passage of oil therebetween and an upper chamber portion, said camshaft housing including first and second housing passageways each having a first end in communication with said upper chamber portion and a second end in communication respectively with said upper journal portion of said camshaft journal for supplying said oil thereto.

A cylinder head assembly in communication with a source of lubrication oil comprising:

• at least one camshaft journal for rotatably supporting a first camshaft;
• at least one hydraulic adjuster guide chamber for slidably receiving a hydraulic adjuster unit therein so as to be operatively engaged with a cam fixed on said first camshaft;
• an oil supply passageway extending longitudinally through said cylinder head assembly for guiding oil within said cylinder head assembly;
• an adjuster passageway having a first end opening into said oil supply passageway in communication therewith and a second end in communication with said hydraulic adjuster guide chamber;
• an oil reserve chamber disposed centrally and above said oil supply passageway having a lower chamber portion which includes an opening in communication with said oil supply passageway for the passage of oil therebetween and an upper chamber portion which has an upper end;
• and
• a journal passageway having a first end in communication with said upper chamber portion proximate said upper end and a second end in communication with said camshaft journal.