Cylindrical vibration damping bushing

A cylindrical vibration damping bushing comprising:

• an outer cylinder having first and second longitudinal ends;
• an inner cylinder coaxially disposed within said outer cylinder, and having an expanded portion at an axially central portion thereof;
• said expanded portion expanding radially outwardly to define a spherical outer surface;
• a pair of cylindrical vibration damping rubber members press fitted between said outer cylinder and said inner cylinder from each longitudinal end of said outer cylinder so as to be joined with said outer cylinder, each said vibration damping rubber member having an inside half portion and an outside half portion;
• and
• a pair of ring-shaped inserts, each formed from a resin material having good slidability, embedded in said inside half portion of each of said cylindrical vibration damping rubber members, whereby an outer surface of each of said pair of ring-shaped inserts is in close contact with said inside half portion of each of said cylindrical vibration damping rubber members;
• each of said ring-shaped inserts having a concave surface for sliding on said spherical outer surface of said expanded portion;
• each of said cylindrical vibration damping rubber members being integrally provided with a projecting portion which projects radially outwardly from said outside half portion, an inside axial surface of each said projecting portion abutting a respective longitudinal end of said outer cylinder, and a seal portion extending from said outside half portion towards an outer surface of a respective end of said inner cylinder;
• a projecting end of each said seal portion being in airtight contact with said respective outer surface of said inner cylinder end.