Oil passage design for a phaser or dual phaser

A method of assembling a pressurized fluid distribution system for a variable cam timing phaser (10) for an internal combustion engine having at least one camshaft (12) comprising:

• providing a stator (14) having an axis of rotation;
• assembling at least one rotor (20, 30) within the stator (14) to be rotatable relative to the axis of rotation of the stator (14) independently of the stator (14) and to define at least one vane-type hydraulic coupling (40, 50) including a combination of a vane (22, 32) and cavity (20a, 30a) associated with the at least one rotor (20, 30) to define first and second variable volume working chambers (20b, 20c;
• 30b, 30c), wherein the first and second variable volume working chambers (20b, 20c;
• 30b, 30c), when selectively communicating with a source of pressurized fluid, facilitate angular phase orientation of the at least one rotor (20, 30) independently with respect to the stator (14);
• and
• assembling a fluid transfer assembly including at least one of:
• a fluid transfer sleeve (72) with respect to the camshaft (12) for rotation therewith, the fluid transfer sleeve (72) having a plurality of pressurized fluid passages (74a, 74b, 74c, 74d) for fluid communication with respect to the first and second variable volume working chambers (20b, 20c, 30b, 30c), each passage (74a, 74b, 74c, 74d) extending in fluid communication with a corresponding circumferentially spaced annular groove segment portion (74f, 74g, 74h, 74i) for selective communication with one of the first and second variable volume working chambers (20b, 20c;
• 30b, 30c) depending on angular orientation of the fluid transfer sleeve (72) during rotation;
• and
• a fluid transfer plate (60) having a plurality of pressurized fluid passages (62a, 62b, 62c, 62d), each passage (62a, 62b, 62c, 62d) extending from a corresponding centrally located port (64a, 64b, 64c, 64d) in fluid communication with a radially extending passage portion (66a, 66b, 66c, 66d) in fluid communication with an arcuately extending passage portion (68a, 68b, 68c, 68d), at least one pressurized fluid passage (62a, 62b, 62c, 62d) on each side (60a, 60b) of the fluid transfer plate (60) for communication with a corresponding one of the first and second variable volume working chambers (20b, 20c;
• 30b, 30c).

In a variable cam timing phaser (10) driven by power transferred from an engine crankshaft and delivered to a concentric camshaft (12) having an inner camshaft (12a) and an outer camshaft (12b) for manipulating corresponding sets of cams, the phaser including a drive stator (14) connectible for rotation with the engine crankshaft;

• first and second driven rotors (20, 30) associated with the stator (14), each driven rotor (20, 30) connectible for rotation with a corresponding one of the inner and outer camshafts (12a, 12b) supporting the corresponding set of cams, wherein the drive stator (14) and the first and second driven rotors (20, 30) are mounted for rotation about a common axis, and first and second vane-type hydraulic couplings (40, 50) for coupling the corresponding first and second driven rotors (20, 30) for rotation with the drive stator (14) and to enable independent phase control of first and second driven rotors (20, 30) relative to the drive stator (14) and relative to each other, the improvement comprising at least one of:
• a fluid transfer sleeve (72) mounted for rotation with the camshaft (12) and having a plurality of pressurized fluid passages (74a, 74b, 74c, 74d), each passage (74a, 74b, 74c, 74d) extending in fluid communication with a corresponding circumferentially spaced annular groove portion (74f, 74g, 74h, 74i) for selective communication with the first and second vane-type hydraulic couplings (40, 50) depending on an angular orientation of the fluid transfer sleeve (72) during rotation;
• and
• a fluid transfer plate (60) having a plurality of pressurized fluid passages (62a, 62b, 62c, 62d), each passage (62a, 62b, 62c, 62d) extending from a corresponding centrally located port (64a, 64b, 64c, 64d) in fluid communication with a radially extending passage portion (66a, 66b, 66c, 66d) in fluid communication with an arcuately extending passage portion (68a, 68b, 68c, 68d), at least one pressurized fluid passage (62a, 62b, 62c, 62d) on each side (60a, 60b) of the at least one fluid transfer plate (60) for communication with a corresponding one of the first and second variable volume working chambers (20b, 20c;
• 30b, 30c).