Rack assist type power steering apparatus

A rack assist type power steering apparatus comprising:

• a rack bar provided with an outer screw groove on an outer circumferential surface;
• a ball nut having an inner screw groove corresponding to the outer screw groove on an inner circumferential surface, and a bearing coupled to an outer circumferential surface;
• and
• a nut pulley provided with a belt coupling portion on an outer peripheral surface, and one end of an inner circumferential surface is provided with a support end coupled to an outer circumferential surface of the ball nut to support the bearing in an axial direction, and an opposite end of an inner circumferential surface is provided with an enlarged diameter portion which is stepped from the support end and increases in inner diameter,
• wherein a support protrusion is formed by protruding from the outer circumferential surface of the ball nut in a location where the support protrusion is in contact with one end of an inner race of the bearing such that the support protrusion supports the one end of the inner race of the bearing in an opposite axial direction.