This application claims the priority of German application 198 18 125.6, filed in Germany on Apr. 23, 1998, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a supporting disc for a supporting disc bearing of open-end spinning rotors comprising a disc-like base body and a running ring made of plastic and having a running surface.
U.S. Pat. No. 4,713,932 exemplifies supporting discs of this general type. Such supporting disc bearings are not in general encapsulated towards the outside. It can occur therefore that fly, trash or avivage establishes itself at the spinning rotors in the area of the support discs, which can lead to an untrue running. In the case of certain running ring materials, it can even happen that so-called chatter marks occur on the running surfaces.
It is an object of the present invention to significantly reduce the polluting of the open-end spinning rotor and also the occurrence of chatter marks.
This object has been achieved in accordance to the present invention in that small, ball-shaped filling bodies are embedded in the running ring.
The filling bodies give the running ring other flexible properties. The ball-shaped filling bodies can be made of plastic or preferably, of glass, and be hollow. The filling bodies are added to the liquid plastic when the running ring is cast onto the base body, namely, according to the application purpose, with a volume of between 0.1 and 10% of the total. The diameter of the ball-shaped filling bodies lies, for example, in the range of 0.1 to 0.3 mm.
Although the filling bodies are distributed over the entire interior of the running ring, they are needed mostly on the running surface. Due to the usual machining of the running surface, a few filling bodies break out of the running surface, so that tiny pores arise thereon. Other filling bodies are cut off during machining, others remain anchored in the running ring and project only partly out of the running surface. The running surface gives the optical impression of being slightly porous. Surprisingly, it has been established that owing to these measures, less trash accumulates on the open-end spinning rotor, and practically no chatter marks occur on the running surfaces of the supporting discs.
The applicants still have no explanation for this phenomenon. It is thought to some extent that due to the ball-shaped filling bodies on the running surface, the heat transfer from the open-end spinning rotors to the running ring is reduced, so that less or even no chatter marks occur. Another explanation could be that a hard skin, which usually forms on the running surface when the plastic cools, does not quite assert itself due to the effect of the filling bodies, so that chatter marks arising as a result of the hard skin do not now occur anymore.
As for the reduced soiling of the open-end spinning rotor, the applicants presume that the filling bodies have an erasing effect and thus keep the open-end spinning rotor constantly clean. The altered temperature and flexing work caused by the filling bodies could also have a positive influence. This seemingly does not involve an increase in wear of the bearing points, as the shafts of the open-end spinning rotors are usually coated against wear.
It is known from German published patent application 19 62 247 to provide the plastic supporting rollers of false twist spindles with hair-like reinforcing elements made of carbon. The aim thereof, however, is to improve the poor heat conducting properties of the plastic, so that the heat can be better conducted to a base body supporting the plastic running ring.