Workbench driving device

The table driving device includes: a first housing in which a first housing hole and a second housing hole are formed; the first bearing is embedded into the first shell hole; a shaft member inserted into the first bearing and the second housing hole; a second housing including an annular portion inserted between an inner peripheral surface surrounding the second housing hole and the shaft member; a second bearing fitted between the annular portion and the shaft member; and a bracket. An annular space adjacent to the bracket side of the second bearing in the axial direction is formed between the annular portion and the shaft member. The bracket includes a first protruding portion inserted into the annular space. The first protruding portion is in contact with an axial end face of the second bearing. The first protruding portion is in contact with at least a part of the inner peripheral surface of the annular portion such that the center of the annular portion is located inside a triangle connecting three poin