Phase varying apparatus for automobile engine

A phase varying apparatus for an automobile engine, comprising:

• a camshaft;
• a drive rotor coaxially mounted on the camshaft, the drive rotor being rotatable about a first rotational axis under a torque exerted by the crankshaft;
• a first control rotor integral with and coaxial with the camshaft;
• a second control rotor coaxially and rotatably mounted on the camshaft;
• a first torquing mechanism for rotating the first control rotor relative to the drive rotor;
• a second torquing mechanism for rotating the second control rotor relative to the first control rotor;
• and
• a reverse rotation mechanism for rotating the first control rotor relative to the drive rotor in association with the second torquing mechanism, in the opposite rotational direction as compared with the rotational direction caused by the action of the first torquing mechanism,
• the phase varying apparatus characterized in that
• the reverse rotation mechanism comprises:
• a first operative mechanism having
• a first radius-decreasing guide groove formed in the first control rotor to extend substantially along the circumference of the first control rotor such that the radius of the first radius-decreasing guide groove from the first rotational axis decreases with the length of the groove,
• a crank member mounted on the drive rotor rotatably about a second rotational axis which is offset from the first rotational axis, and
• a first pin mechanism mounted on the crank member such that the pin mechanism is in engagement with the first radius-decreasing curved guide groove slidably in one direction of the guide groove under the action of the first torquing mechanism;
• and
• a second operative mechanism for rotating the first control rotor relative to the drive rotor in the opposite rotational direction with respect to the rotation thereof caused by the action of the first torquing mechanism, by moving the first pin mechanism in the first radial guide groove in the other direction, under the action of the second torquing mechanism.