Patent ID: 8858083

Claim:
A motion guide device, comprising: a raceway rail on which rolling elements roll along a longitudinal direction of the raceway rail; a moving block which is assembled to the raceway rail through intermediation of a large number of the rolling elements, the moving block comprising an endless circulation path for the large number of the rolling elements and being movable along the raceway rail; and spacers each interposed between adjacent ones of the large number of the rolling elements in the endless circulation path of the moving block, wherein the moving block comprises: a block body comprising: a load rolling element path in which the large number of the rolling elements roll under load between the moving block and the raceway rail; and a rolling element return path parallel to the load rolling element path; and a pair of turning path forming members each comprising a direction turning path for coupling the load rolling element path and the rolling element return path to each other so as to form the endless circulation path, the pair of turning path forming members being fixed to the block body, and wherein the direction turning path comprises: a turning portion for continuously varying a rolling direction of the large number of the rolling elements; and a preliminary turning portion which includes an outer surface formed in a linear shape that extends from the rolling element return path of the block body and is continuous with the rolling element return path so as to couple the rolling element return path and the turning portion to each other, the preliminary turning portion allowing the spacers to move in a curved form while linearly guiding the large number of the rolling elements.