The present disclosure provides a seat position adjustment apparatus with improved assemblability, wherein the assemblability is improved and the weight is reduced by individually modifying the shapes of a mounting part and a gear part and improving their coupling structure, the seat position adjustment apparatus including a driving unit including a motor in which a drive shaft is formed, a gear part, wherein a curved surface part extending along a direction of rotation about a first axis extending bilaterally is formed in an outer portion of the gear part, and the gear part is gear-coupled to the drive shaft, a rod part coupled to the gear part such that the rod part passes through the gear part, receives power from the drive shaft, and moves forward or rearward, and a mounting part, wherein upper portions of a curved plate structure surrounding the curved surface part at a front and a rear of the gear part, respectively, envelop the rod part to form respective through-holes each having a vertical length that is relatively greater than a vertical thickness of the rod part, wherein, in a state in which the mounting part is fixed, a seat connected to the rod part is moved in accordance with a movement of the rod part.

A seat adjustment device may have a first lead screw, a second lead screw, and a connector. A first portion of the connector may comprise threads that may be adapted to receive threads from the first lead screw. A second portion of the connector may comprise threads that are adapted to receive threads from the second lead screw.

A vehicle seat may have at least one seat structure and an adjustment device with at least one pivot mechanism for pivoting the seat structure about a pivot axis. The seat structure may have at least one seat frame and a seat shell that is pivotally mounted on the seat frame. The pivot mechanism may be coupled to the seat structure and may be designed to move the seat frame about the pivot axis and, depending on a pivot direction of the seat frame, to move the seat shell relative to same and in a pivot direction opposite the pivot direction of the seat frame.