Bearing and drive arrangement for an open-end spinning turbine

#The present invention relates to a bearing and drive structure for an open-end spinning turbine, the turbine including a spinning rotor mounted by means of at least one elastically suspended slide or roller bearing bush and drive for the rotor being provided by a motor presenting a narrow motor air gap between a rotor member utilized for the drive and a stator member disposed oppositely thereto and carrying stator windings.

#Such a bearing and drive arrangement is disclosed in German Offenlegungsschrift [Laid-Open Application] No. 2,404,241 and corresponding U.S. application Ser. No. 695,551, filed by Heinz Wehde on June 14, 1976.

#In addition to the above-mentioned motor air gap, the spinning turbine of the above-mentioned previously disclosed arrangement also has, of course, an air gap between the outer surface of the rotor and the stationary housing surrounding the rotor.

#FIG. 1 is an elevational, cross-sectional view of a preferred embodiment of the invention having a radial pair of surfaces and an axial pair of surfaces.

#FIG. 2 is a view similar to that of FIG. 1 of a second preferred embodiment having two axial pairs of faces and one pair of surfaces at the frontal face.

#FIG. 3 is a view similar to that of FIG. 1 of a third preferred embodiment having a conical pair of surfaces and a radial pair of surfaces.

#The embodiment shown in FIG. 1 includes a stator 1, a bearing bush 5 elastically mounted in a bore 2 of the stator 1 by means of O-rings 3 and 4 and a stator motor winding 6 secured around the stator.

#A thin shaft or pin 7 secured to the rotor projects into the bearing bush 5 to form a journal bearing therewith. This shaft 7 supports the spinning rotor 8 which has a funnel-like front end defining a trough 16 in which spinning takes place, and a cylindrical cup-shaped rotor part 9 which carries a conductive flux return ring 11 and radially magnetized, circumferentially distributed rotor magnets 10.

#In the air gap 12 extending between the stator 1 and the cylindrical rotor part 9, there is placed a ring 13 which is fastened to the stator and which extends along a significant portion of the axial length of the rotor at a small distance of 0.3 mm from the outer surface of rotor part 9. The surfaces of part 9 and ring 13 bordering the resulting air gap 14, which is narrower than the motor air gap 15, form a dynamic air bearing which stabilizes the position of the rotor during rotation. If an asymmetrical force is applied during run-down of the rotor, for example by means of a cleaning brush pressed into groove 16, these surfaces limit the extent to which the rotor can tilt relative to the stator and thus act to prevent the rotor from being tilted too much with respect to the stator. Thus forces exceeding a certain magnitude are prevented from being imposed on the rotor journal bearing.