Valve timing control device

A valve timing control device comprising:

• a rotary member adapted to be rotatably arranged in a torque transmitting route between a crankshaft of an internal combustion engine and a camshaft of the internal combustion engine;
• a first annular spring space formed in the rotary member, the first annular spring space having an annular inner circumferential wall and an annular outer circumferential wall;
• a rotational transmitting member rotatable relative to the rotary member;
• a second annular spring space formed in the rotational transmitting member, the second annular spring space having an annular inner circumferential wall and an annular outer circumferential wall;
• a pressure chamber formed by the rotary member and the rotational transmitting member;
• a vane provided on the rotary member or the rotational transmitting member dividing the pressure chamber into an advancing chamber and a delaying chamber;
• a helical spring positioned in the first and second annular spring spaces to urge the rotary member in the advancing direction to expand the advancing chamber, the helical spring having a coil portion, a first end portion and a second end portion;
• the first end portion of the helical spring engaging a first groove formed in one of the inner circumferential wall of the rotary member and the outer circumferential wall of the rotary member;
• and
• the second end portion of the helical spring engaging a second groove formed in one of the inner circumferential wall of the rotational transmitting member and the outer circumferential wall of the rotational transmitting member.