Method for mounting of an integral structural unit in an electromechanical motor vehicle steering system having a torque sensor unit and a steering angle sensor unit by means of ultrasonic welding

A method for mounting an integral component in an electromechanical power steering for a motor vehicle, comprising a steering shaft which is rotatably mounted about a steering shaft axis of rotation and which comprises an upper steering shaft and a lower steering shaft, which are joined together by a torsion bar, wherein the integral component has a sensor unit, comprising a torque sensor unit, which is configured to detect rotation of the upper steering shaft relative to the lower steering shaft, and/or a steering angle sensor unit, which measures the absolute steering angle of the lower steering shaft or the upper steering shaft with a spur gearing, wherein the sensor unit comprises a ring magnet rotationally fixed to the upper steering shaft or lower steering shaft, and wherein a magnetic sensor is configured to detect rotation of the steering shaft connected to the ring magnet, and wherein the ring magnet is carried by a part in the shape of a ring magnet sleeve or a stator holder, the part being arranged on the upper steering shaft or the lower steering shaft, the method comprising:

• providing the ring magnet sleeve and/or the stator holder made of a thermoplastic material;
• positioning the ring magnet sleeve and/or the stator holder on the upper steering shaft or the lower steering shaft with a selected contact pressure;
• introducing a high-frequency mechanical vibration in the ultrasound range into the corresponding steering shaft;
• and
• pressing the corresponding steering shaft into the ring magnet sleeve and/or the stator holder with a selected contact pressure.