Variable cam timing phaser

A variable cam timing phaser of a variable cam timing system, with the variable cam timing system including a camshaft, said variable cam timing phaser comprising:

• a housing having a housing wall disposed about an axis and defining a housing interior, with said housing having a first housing side facing a first direction along said axis and a second housing side facing a second direction opposite said first direction;
• a rotor disposed within said housing interior and moveable with respect to said housing, with said rotor having a hub and a plurality of vanes extending from said hub away from said axis toward said housing wall, and with said rotor and said housing defining a plurality of chambers with each chamber of said plurality of chambers having an advance chamber and a retard chamber;
• a first end plate coupled to said first housing side and further defining said plurality of chambers;
• a second end plate coupled to said second housing side and further defining said plurality of chambers;
• at least one air vent located at a center of rotation region of at least one of said housing, said rotor, said first end plate, or said second end plate;
• wherein said center of rotation region is defined as being relative to rotational motion of the variable cam timing phaser;
• wherein air brought to said center of rotation region during use of the variable cam timing phaser and received in said at least one air vent escapes hydraulic fluid remaining in the variable cam timing phaser;
• wherein said at least one air vent is fluidly coupled to said plurality of chambers and is configured to vent air from said plurality of chambers, and wherein said at least one air vent is defined by at least one of said rotor, said first end plate, said second end plate, and said housing;
• and
• a reservoir fluidly coupled to said at least one air vent, wherein said reservoir is configured to retain hydraulic fluid and is configured to reduce air from being ingested through said at least one air vent and into the plurality of chambers;
• wherein said reservoir is fluidly coupled to said at least one air vent at a maximum radius of said reservoir from said axis, and said reservoir is fluidly coupled to the atmosphere at a minimum radius of said reservoir from said axis.