Variable camshaft timing system for internal combustion engine utilizing flywheel energy for reduced camshaft torsionals

A method of operating an internal combustion engine having a rotatable crankshaft and a rotatable camshaft, the camshaft being position variable relative during the operation thereof, said camshaft having a weighted body fixedly attached thereto for rotation therewith to counteract torque reversals in said camshaft, the method comprising:

• providing the camshaft with a vane at least one lobe, the vane being rotatable with the camshaft and being non-oscillatable with respect to the camshaft;
• providing the camshaft with a housing having at least one recess, the housing being rotatable with the camshaft and being oscillatable with respect to the camshaft, the at least one recess of the housing receiving the at least one lobe of the vane and permitting oscillation of the at least one lobe within the at least one recess as the housing oscillates with respect to the camshaft;
• providing conduit means permitting unobstructed flow of a hydraulic fluid to and from said at least one recess;
• providing means for varying the position of the housing relative to the camshaft;
• and
• actuating the means for varying the position of the housing relative to the camshaft in reaction to torque reversals in the camshaft.

An internal combustion engine comprising:

• a crankshaft, said crankshaft being rotatable about an axis;
• a camshaft, said camshaft being rotatable about a second axis, said second axis being parallel to said axis, said camshaft being subject to torque reversals during the rotation thereof;
• a weighted body fixedly attached to said camshaft for rotation therewith to counteract torque reversals in said camshaft;
• a vane having at least one lobe, said vane being attached to said camshaft, being rotatable with said camshaft and being non-oscillatable with respect to said camshaft;
• a housing which is rotatable with said camshaft and being oscillatable with respect to said camshaft, said housing having at least one recess, said at least one recess receiving said at least one lobe, said at least one lobe being oscillatable within said at least one recess;
• conduit means permitting unobstructed flow of a hydraulic fluid to and from said at least one recess;
• and
• means reactive to torque reversals in the camshaft for varying the position of the housing relative to the camshaft.

An internal combustion engine comprising:

• a crankshaft, said crankshaft being rotatable about an axis;
• a camshaft, said camshaft being rotatable about a second axis, said second axis being parallel to said axis, said camshaft being subject to torque reversals during the rotation thereof;
• a weighted body fixedly attached to said camshaft for rotation therewith to counteract torque reversals in said camshaft;
• a vane having first and second circumferentially spaced apart lobes, said vane being attached to said camshaft, being rotatable with said camshaft and being non-oscillatable with respect to said camshaft;
• a housing which is rotatable with said camshaft and which is oscillatable with respect to said camshaft and having first and second circumferentially spaced apart recesses, each of said first and second recesses receiving one of said first and second lobes and permitting oscillating movement of said one of said first and second lobes therein;
• conduit means permitting unobstructed flow of a hydraulic fluid to and from said first and second recesses;
• and
• means reactive to torque reversals in the camshaft for varying the position of the housing relative to the camshaft.

An internal combustion engine comprising:

• a crankshaft, said crankshaft being rotatable about an axis;
• a camshaft, said camshaft being rotatable about a second axis, said second axis being parallel to said axis, said camshaft being subject to torque reversals during the rotation thereof;
• a weighted body fixedly attached to said camshaft for rotation therewith to counteract torque reversals in said camshaft;
• a vane having only one lobe, said vane being attached to said camshaft, being rotatable with said camshaft and being non-oscillatable with respect to said camshaft;
• a housing which is rotatable with said camshaft and being oscillatable with respect to said camshaft, said housing having only one recess, said only one recess receiving said at only one lobe, said only one lobe being oscillatable within said only one recess;
• conduit means permitting unobstructed flow of a hydraulic fluid to and from said only the recess;
• and
• means reactive to torque reversals in the camshaft for varying the position of the housing relative to the camshaft.