The centering member (8) projects from the centering element (7).

The centring member (10) is axially prestressed by the metal bellows (8) and presses against another centring member (14) via rollers (12).

The centering pad can be removed for more thorough cleaning.

Figure 1-10: Press the axis of the motor unit completely inside the centering part.

The fine-centring system consists of a tubular end-piece (7) secured to the drive shaft and bearing a metal bellows (8) and a centring member (10) connected thereto.

The problems arising in adhesively securing the centring component of a conical loudspeaker to the moulded plastic loudspeaker frame may be avoided by means of a process in which the centring component is welded to the loudspeaker frame.

According to the invention, the spring (31) presses on a reaction piston (32), a centring component (24) of which acts on rolling bodies (30) in the centring system (25).

The center of the positioning element further has a centering member (8) whose outer diameter is adapted to the second center opening of the compact disk.

The centring member (14) is, according to the invention, part of an inner race (15) of a needle-roller bearing (16) which is pressed on the end piece (1B) of the torsion bar (2) connected to the drive shaft (3).

To this end a circular step for securing to the centring component is made on the frame with a peripheral rib on the upper side.

The invention concerns a device wherein the toothbrush neck (2) comprises a centring component, a U-shaped tenon (20) extending the brush neck (2) to be engaged in a mortise (10) of the other separable element, namely the head (1) of the brush.