Timing-range gear

A variable valve timing device of an internal combustion engine for adjusting relative angular position between a crankshaft and a camshaft having a central longitudinal axis wherein:

• a pulley means having a circular periphery with teeth by which in a phased relation to a driving pulley of the crankshaft is being driven through a flat and toothed timing belt means, a first planar side being adjacent to a camshaft support means, a second side forward from said first side being substantially parallel thereto, a first bore extending longitudinally inward from said first side to a first planar bottom surface thereof, a second bore being concentric to said first bore and extending forward from the bottom surface thereof to a second planar surface that is perpendicular thereto, a third bore from said second planar surface extending through said pulley means and at least one inside helical groove cut into the periphery of said third bore throughout the length thereof, an inside groove circumferentially cut within said first bore being substantially near said first side;
• a hub member having a first load-bearing circular periphery concentric to the longitudinal axis and a length substantially equal to the space between an inner edge of the inside groove and the first bottom surface in rotatably sliding contact with the periphery of said first bore of said pulley member, a first outer planar surface being perpendicular to the periphery and extending centerward therefrom, a second outer planar surface, a first inner planar surface extending centerward from said periphery and being perpendicular thereto, a shallow undercut extending longitudinally from the inner planar surface toward the first outer surface and having a flat bottom surface perpendicular to said periphery, a second concentric load-bearing periphery smaller in diameter than said first periphery extends from said undercut outward therefrom, a third concentric load-bearing periphery reduced in diameter extends to the outer end of the hub and having at least one outside helical groove cut thereon through the length of said periphery, a circumferential flat-bottom groove cut in said first periphery near the first outer planar surface, a first bore concentric to said periphery extending longitudinally inward from said first side and having a first inside flat-bottom groove concentric to the longitudinally axis in close proximity to an outer edge thereof, a second inside groove larger than said first groove therein, a third inside groove identical to the first inside groove being concentric to the longitudinal axis and in close proximity to an inner bottom surface of said first bore, a second inside bore concentric to the longitudinal axis through the hub member and having an inside keyway longitudinally cut therein, an angular end surface extends outward therefrom, at least one passageway angularly extending through the flat bottom of said under cut and intersects the second inside groove within said first bore;
• an annular piston means comprising:
• a first load-bearing circular periphery concentric to the longitudinal axis and in rotatable sliding contact with the periphery of the second bore of said pulley member, a second circular load-bearing periphery concentric to the longitudinal axis being smaller in diameter than said first periphery and concavely conjoined thereto, a first load-bearing bore concentric to said first periphery and in rotatable sliding contact with the second load-bearing periphery of said hub member, a piston head being annular and extending centerward from said first periphery to said first bore, an outside flat-bottom groove circumferentially cut into said first periphery, an inside flat-bottom groove circumferentially cut into the periphery of said first bore, a second load-bearing bore extending forward from a bottom of said first bore and concentric thereto, at least one outside helical spline means extending forward from the end of said first periphery to an outer end of said piston means and convolutional with the inside helical groove within the third bore of said pulley member, at least one inside helical spline rising centerward from the load-bearing surface of said second bore and extending the full length thereof and convolutional with the outside helical groove within the third load-bearing periphery of said hub member;
• the camshaft having an end journal extending beyond the bearing support therefor, a reduced diameter end portion extend outward from the end of said journal and coaxial thereto, a keyway longitudinally cut into the periphery of said reduced diameter end, a first hole concentric to the longitudinal axis leading inward from the outer end of said reduced diameter end and having a threaded portion therein, a blind hole coaxial to said first hole, a first passageway leading inward from the periphery of said journal and in communication with said blind hole and oil-pressure supply port within said bearing support means, a second passageway substantially near the reduced diameter end of said journal leading inward from the periphery and in communication with the first hole and the second inside groove within the first bore of said hub member, a key longitudinally interfaced within the keyways therefor in said hub and the reduced diameter portion of the camshaft, a circular end plate having a periphery substantially coangular with the end of said hub member and a cavity which interlockingly receives the overhanging end of said key thereinbetween.