A torsion washer of the present disclosure includes a base portion and an elastic unit extended from the base portion. The elastic unit includes an external elastic arm and a torsion-adjusting arm arranged inside the external elastic arm. A space surrounded by the base portion and the external elastic arm is divided into a hole and a slot, in air communication with the hole, by using the torsion-adjusting arm. A distance, i.e., a radius, between the external elastic arm and a center of the hole is larger than a distance, i.e., an interference distance, between the torsion-adjusting arm and the center of the hole. Moreover, the present disclosure provides a torsion device including a plurality of the torsion washers and a shaft coupling through the holes of the torsion washers, and the shaft is configured to selectively contact each torsion-adjusting arm.

A torsion washer integrally formed as a one-piece structure includes an external ring-shaped portion, a first abutting arm and a second abutting arm both separately extending from an inner edge of the external ring-shaped portion, and a connecting lever connecting the first and second abutting arms. The inner edge includes a first arc segment and an opposite second arc segment, and centers of circle of the first and second arc segments are located in a space surrounded by the inner edge. Free ends of the first and second abutting arms do not contact the inner edge. A distance between a first abutting portion of the first abutting arm and the first center of circle is less than a radius of the first arc segment. The connecting lever is spaced apart from the inner edge, allowing the first and second abutting arms to be interlinked with each other.

A drive device, in particular for an adjustable vehicle flap, comprising includes a housing extending axially along a drive axle, a motor for generating a driving force in the direction of the drive axle, a first drive element, and a coupling device arranged between the motor and the first drive element. The coupling device comprises a coupling housing and at least one first coupling part with a coupling section for coupling to the first drive element. The first drive element is coupled to the coupling device via the coupling section of the first coupling part, and a braking device for braking a drive movement of the first drive element. A drive device, in particular for an adjustable vehicle flap, which has a lower residual installation length and can thus be used more flexibly in various installation space situations is created by the braking device being arranged axially in the coupling section of the first coupling part.