Roller retainer, roller screw using roller retainer and rolling guide apparatus using roller retainer

A roller screw comprising:

• a track shaft including a spiral-shaped roller rolling groove having a V-shaped section;
• a slide member including a roller circulation passage including a spiral-shaped load rolling groove having a V-shaped section and assembled to said track shaft so as to move with respect to said track shaft, said load rolling groove corresponding to said roller rolling groove;
• a plurality of rollers arranged and stored in said roller circulation passage and allowed to circulate through said roller circulation passage in linking with the relative motion of said slide member with respect to said track shaft;
• and
• a plurality of retainers for holding said plurality of rollers individually so that said rollers are rotated and slid;
• wherein each of said roller retainers encloses the outer periphery of its associated one of said rollers that is situated on a diagonal when said roller is viewed from the side surface thereof, and also wherein, in at least one of said roller rolling groove and said load rolling groove, there is formed a guide groove for guiding said roller retainer.