Roller connecting and retaining device

A roller connecting and retaining device comprises two connecting portions, a plurality of retaining portions and spacer portions. The retaining portions are oppositely arranged in pairs and connected vertically to the connecting portions. The spacer portions are connected between the upper end and the lower end of the paired opposite retaining portions. Two contacting edges are formed at both sides of the respective spacer portions and have a linear contact with the rolling surface of the rollers, and the contacting edges of the opposite spacer portions are located correspondingly to the axial center of the rollers and are arranged at both sides of the inactive contact surface of the rollers. A mold-releasing concave is formed in each conjunction between the spacer portion and the retaining portion. Such design facilitates injection molding process, mold opening, and mass production. The contacting edge of the opposite spacer portions can prevent the problems of the rollers during rolling motion, such as slant position, friction, impact and skip.