Closure assembly for a camshaft phaser

A closure assembly for a camshaft phaser, comprising:

• a) a plate having a central opening and supportive of a plurality of circumferentially spaced-apart first projection elements surrounding said central opening;
• b) a closure extending across said central opening and supporting a plurality of circumferentially spaced-apart second projection elements disposed along the periphery of said closure;
• and
• c) a seal disposed between said plate and said closure for preventing fluid leakage therebetween,
• wherein said first and second projection elements are lockably associated by coaxial rotation of said plate and said closure with respect to one another through a portion of a full revolution, wherein at least one of said plurality of circumferentially spaced-apart second projection elements includes a rotational locking mechanism, and wherein said rotational locking mechanism includes a radially flexible first tip and a radially rigid second tip.