Buckle assembly and seat belt buckle

A buckle assembly, comprising

• a buckle configured to engage with a latch plate to secure a seat belt to a seat;
• wherein:
• the buckle assembly further comprises a force-limiting module connected to the buckle and configured to define a force threshold, and
• the force-limiting module comprises:
• a mandrel having a hollow structure and rotatably supported at two axial ends;
• a torsion bar positioned in a hollow inner cavity of the mandrel to be arranged coaxially with the mandrel, only a portion of the torsion bar being connected to the mandrel in a co-rotatable manner;
• and
• a winding component having a winding portion wound around an outer circumferential surface of the mandrel and a fixing portion fixed to the buckle;
• and
• when a force applied to the buckle is greater the force threshold defined by the force-limiting module, the torsion bar undergoes torsional deformation by co-rotating with the mandrel at the only connected portion of the torsion bar, while the winding portion of the winding component gradually unwinds from the outer circumferential surface of the mandrel as the mandrel rotates, so that the buckle can move to increase the distance between the buckle and the force-limiting module.