Production method and production apparatus for ring-shaped part

A production apparatus for a ring-shaped part, the apparatus comprising:

• a material rotating mechanism which causes a cylindrical material made of resin to rotate around an axial direction thereof;
• a first cutting blade moving mechanism which causes a first cutting blade to move, and cuts an inner circumferential side of the cylindrical material while forming a semicircular track, by causing the first cutting blade to reciprocate in a radial direction of the cylindrical material from a state contacting a thickness center of one end of the cylindrical material which is rotating by way of the material rotating mechanism, and causing to move to a side of an other end of the cylindrical material in an axial direction;
• a second cutting blade moving mechanism which causes a second cutting blade to move, and cuts an outer circumferential side of the cylindrical material while forming a semicircular track, by causing the second cutting blade to reciprocate in a radial direction of the cylindrical material from a state contacting the thickness center of the one end of the cylindrical material which is rotating, and causing to move to a side of the other end of the cylindrical material in the axial direction;
• and
• a third cutting blade moving mechanism which causes a third cutting blade to move, and contacts the third cutting blade to a side of the other end of a portion of the cylindrical material which has had an inner circumferential side and an outer circumferential side cut and is rotating, and separates portion of the cylindrical material from a remainder of the cylindrical material by severing to obtain a ring-shaped part having a substantially circular cross-section.