Friction disc for a false-twist device

Abstract

Friction disc for a false-twist device, comprising an annular hub, on which it is possible to fix a circular race formed by a polyurethane (PU) layer and has a minimum wall thickness required for a secure interlocking fit, the hub having a circumferential support ring and a central hole, by which the friction disc is fixed on one of the shafts of the false-twist device. To ensure better dimensional and form stability over a long service life of the friction disc, the formed race fixed on the hub is ground according to a predefinable profile such that the flanks of the race have a predefinable width dimension following the grinding process, and/or in that the hub has, at a spacing from the support ring, a circumferential shoulder for abutment for the fixable PU layer, a cross-sectional width of the shoulder being smaller than a cross-sectional width of the support ring.

What is claimed is: 
     
         1 . A friction disc for a false-twist device, comprising an annular hub, on which a circular race is fixable that is formed by a polyurethane (PU) layer and has a minimum wall thickness required for a secure interlocking fit, the hub having a circumferential support ring and a central hole, by which the friction disc is fixable on one of the shafts of the false-twist device,
 characterized in that   the formed race fixed on the hub is ground according to a predefinable profile such that the flanks of the race have a predefinable width dimension following the grinding process; and/or   the hub has, at a spacing from the support ring, a circumferential shoulder for abutment for the fixable PU layer, a cross-sectional width of the shoulder being smaller than a cross-sectional width of the support ring.   
     
     
         2 . The friction disc according to  claim 1 , characterized in that the width dimension of the flanks of the formed race fixed on the hub is equal to or smaller than the maximum cross-sectional width of the hub. 
     
     
         3 . The friction disc according to  claim 2 , characterized in that the wall thickness of the PU layer of the race is minimized to the minimum wall thickness required for the secure interlocking fit. 
     
     
         4 . The friction disc according to  claim 1 , characterized in that the hub is made of a plastic material. 
     
     
         5 . The friction disc according to  claim 4 , characterized in that the hub is made of polybutylene terephthalate (PBT). 
     
     
         6 . The friction disc according to  claim 1 , characterized in that the PU layer of the formed race fixed on the hub has a hardness of at least 85 Shore A. 
     
     
         7 . The friction disc according to  claim 1 , characterized in that the hub has at least one passage which passes through the hub in order to channel, in a predefined manner, the air flowing through the at least one passage during rotational operation of the friction disc. 
     
     
         8 . The friction disc according to  claim 7 , characterized in that the at least one passage is designed such that the air flowing through the at least one passage during rotational operation of the friction disc leads towards an additional friction disc of the false-twist device arranged adjacently to the friction disc. 
     
     
         9 . The friction disc according to  claim 7 , characterized in that the hub forms a fan shape having a plurality of passages, which are separated from one another by a partition having a predetermined blade geometry for the defined channeling of the air flowing therethrough. 
     
     
         10 . The friction disc according to  claim 8 , characterized in that the hub forms a fan shape having a plurality of passages, which are separated from one another by a partition having a predetermined blade geometry for the defined channelling of the air flowing therethrough. 
     
     
         11 . A false-twist device comprising a bearing block having at least one rotatably mounted shaft comprising at least two friction discs arranged along the shaft at a spacing from each other thereon, characterized in that one of the friction discs is a friction disc according  claim 8 . 
     
     
         12 . A false-twist device comprising a bearing block having at least one rotatably mounted shaft comprising at least two friction discs arranged along the shaft at a spacing from each other thereon, characterized in that one of the friction discs is a friction disc according to  claim 9 .