Linear extension and retraction mechanism and robot arm mechanism.

摘要

One purpose of the invention is to reduce the production cost of a linear extension and retraction mechanism and a robotic arm mechanism. A linear extension and retraction mechanism includes: a plurality of first pieces 53 that are flexibly connected to each other; a plurality of second pieces 54 flexibly connected to each other; a plurality of rollers 59 configured to connect the first pieces and the second pieces together, to form a columnar body, and to movably support the columnar body in the forward and backward directions; a drive gear 56 configured to move the first pieces and the second pieces back and forth; and a motor unit configured to generate power for rotating the drive gear. On a surface on a side where each of the first pieces is connected to a corresponding one of the second pieces, the first piece comprises a linear gear 539 for meshing with the drive gear and a projection fixed so as to be toward the side of the second piece protrudes. At least a third piece 63 is bendably connected to a rearmost of the plurality of first pieces.