Hydraulic valve timing adjusting apparatus

A hydraulic valve timing adjusting apparatus to be provided in a driving force transmission system for transmitting driving force to a camshaft with a cam for opening and closing an intake valve or an exhaust valve, comprising:

• a housing assembly;
• a rotor provided so as to be relatively rotatable with respect to said housing assembly;
• an advancing hydraulic chamber and a retarding hydraulic chamber formed between said rotor and said housing assembly;
• a convex member provided in one of said housing assembly and said rotor so as to be slidable therein;
• a recessed portion provided in another one of said housing assembly and said rotor so as to be engageable with said convex member;
• an urging member for urging said convex member toward said recessed portion;
• and
• an oil passage including a hydraulic switching device which is able to supply oil pressure in either of said advancing hydraulic chamber and said retarding hydraulic chamber to said recessed portion;
• wherein when said oil pressure is supplied to said advancing hydraulic chamber, said rotor is relatively rotated in an advancing direction with respect to said housing assembly, and when said oil pressure is supplied to said retarding hydraulic chamber, said rotor is relatively rotated in a retarding direction with respect to said housing assembly,
• wherein when said oil pressure switched by said hydraulic switching device is supplied to said recessed portion, said convex member is slid in a direction opposite to said recessed portion to release engagement between the convex member and said recessed portion thereby enabling relative rotation of said housing assembly and said rotor in response to said oil pressure in said hydraulic chambers, and
• wherein said hydraulic switching device is provided in the rotor.

A hydraulic valve timing adjusting apparatus to be provided in a driving force transmission system for transmitting driving force to a camshaft with a cam for opening and closing an intake valve or an exhaust valve, comprising:

• a housing assembly;
• a rotor provided so as to be relatively rotatable with respect to said housing assembly;
• an advancing hydraulic chamber and a retarding hydraulic chamber formed between said rotor and said housing assembly;
• a convex member provided in one of said housing assembly and said rotor so as to be slidable therein;
• a recessed portion provided in another one of said housing assembly and said rotor so as to be engageable with said convex member;
• an urging member for urging said convex member toward said recessed portion;
• and
• an oil passage including a hydraulic switching device which is able to supply oil pressure in either one of an oil passage communicating with said advancing hydraulic chamber and an oil passage communicating with said retarding hydraulic chamber to said recessed portion;
• wherein when said oil pressure is supplied to said advancing hydraulic chamber, said rotor is relatively rotated in an advancing direction with respect to said housing assembly, and when said oil pressure is supplied to said retarding hydraulic chamber, said rotor is relatively rotated in a retarding direction with respect to said housing assembly,
• wherein when said oil pressure switched by said hydraulic switching device is supplied to said recessed portion, said convex member is slid in a direction opposite to said recessed portion to release engagement between the convex member and said recessed portion thereby enabling relative rotation of said housing assembly and said rotor in response to said oil pressure in said hydraulic chambers, and
• wherein said hydraulic switching device is provided in the rotor.