The invention relates to a load-bearing seatbelt retractor for a seat structure of a vehicle seat, the seatbelt retractor having two housing halves between which functional modules of the seatbelt retractor are disposed. One functional module is a belt reel having a winding axis. The two housing halves form two mutually parallel receptacles in the seatbelt retractor, which are oriented perpendicular to the winding axis. Two seat bars can be inserted into the receptacles. The two housing halves are in contact at least on two contact lines above and below the functional modules with respect to an insertion direction of the receptacles. The lower contact line splits open on both sides along the winding axis such that respective intermediate spaces open toward the receptacles are formed.

A seat belt retractor includes a winding drum, a locking base, and a pretensioner. The pretensioner includes a drive wheel, a pressure container, and a moving member. The pressure container is provided such that an opening direction of the terminal end portion is tilted toward the winding drum or opposite to the winding drum, with respect to a plane orthogonal to an axial direction of the winding drum. When the pretensioner is activated, the moving member moves the locking base, the drive wheel, and the winding drum to the opening direction side of the terminal end portion of the pressure container in the axial direction of the winding drum, and brings one of the locking base, the drive wheel, and the winding drum into contact with a restricting member.

A gas generator includes: an ignition device including an igniter, an igniter holding portion having a tubular shape and being configured to hold the igniter and a fixing portion made of resin and being configured to fix the igniter to the igniter holding portion; and a case having a bottomed tubular shape and being configured to accommodate a gas generating agent which combusts by actuation of the ignition device, the case being made of resin and including a side wall portion with a base end side being connected to the fixing portion, and a closing end portion configured to close a tip end side. The case includes an inclined surface extending obliquely with respect to an axial direction of the case on the tip end side, and a fragile part formed at an edge portion excluding at least a base end portion of the inclined surface.