Open-end spinning frame

Abstract

An open-end spinning frame ( 1 ) having a spinning rotor ( 3 ), whose rotor shaft ( 4 ) is supported, free of axial thrust, in the bearing wedge of a support disk bearing arrangement ( 5 ) and is fixed in place by means of a magnetic axial bearing ( 18 ). The axial bearing ( 18 ) has a stationary magnetic bearing component ( 27 ) fixed on the bearing housing ( 26 ), and a rotating magnetic bearing component ( 44 ) arranged at the end of the rotor shaft and having at least two annular shoulders ( 46 ) defined by recesses ( 47 ) in the rotor shaft ( 4 ). The sharpness of the annular shoulders ( 46 ) is reduced in the area between their outer circumference ( 58 ) and the adjoining radial faces ( 50 ) of each annular shoulder, e.g., via curved or beveled surfaces in such area, and the base surfaces ( 49 ) of the recesses ( 47 ) are each connected via rounded sections ( 51 ) with the radial faces ( 50 ) of the adjoining annular shoulders ( 46 ).

1. An open-end spinning frame having a spinning rotor, a rotor shaft fixed coaxially with the spinning rotor, a support disk bearing arrangement defining a bearing wedge for supporting therein the rotor shaft without imposing axial thrust thereon, a magnetic axial bearing having a bearing housing, a stationary magnetic bearing component fixed in the bearing housing, and a rotating magnetic bearing component arranged at an end area of the rotor shaft, the rotating magnetic bearing component comprising at least two ferromagnetic annular shoulders defined by adjacent recesses in the rotor shaft, each annular shoulder having opposed radial faces and a generally rounded outer circumference extending therebetween and each recess having a base circumference connected via rounded annular surfaces with the radial faces of the adjacent annular shoulders. 
     
     
       2. The open-end spinning frame in accordance with  claim 1 , characterized in that the ratio of the length of the rotor shaft to the diameter of the rotor shaft is less than about 12:1. 
     
     
       3. The open-end spinning frame in accordance with  claim 1 , characterized in that the ratio of the length of the rotor shaft to the diameter of the rotor shaft is about 11.33:1. 
     
     
       4. The open-end spinning frame in accordance with  claim 1 , characterized in that the rotor shaft has a length of less than about 100 mm. 
     
     
       5. The open-end spinning frame in accordance with  claim 1 , characterized in that the rotor shaft has a length of about 93.5 mm. 
     
     
       6. The open-end spinning frame in accordance with  claim 1 , characterized in that the generally rounded outer circumference of each of the annular shoulders comprises curved annular sections extending between an exterior circumferential surface and the adjacent radial faces. 
     
     
       7. The open-end spinning frame in accordance with  claim 6 , characterized in that each of the curved sections in the area of the exterior circumferential surface has an axial dimension of between about 0.1 mm and about 0.5 mm. 
     
     
       8. The open-end spinning frame in accordance with  claim 6 , characterized in that each of the curved sections in the area of the exterior circumferential surface has an axial dimension of about 0.3 mm. 
     
     
       9. The open-end spinning frame in accordance with  claim 1 , characterized in that the generally rounded outer circumference of each of the annular shoulders comprises beveled annular sections extending between an exterior circumferential surface and the adjacent radial faces. 
     
     
       10. The open-end spinning frame in accordance with  claim 1 , characterized in that the rounded annular surfaces of each recess between the base circumference thereof and the radial faces of the adjacent annular shoulders have a dimension of between about 0.2 mm and about 1.5 mm. 
     
     
       11. The open-end spinning frame in accordance with  claim 1 , characterized in that the rounded annular surfaces of each recess between the base circumference thereof and the radial faces of the adjacent annular shoulders have a dimension of about 0.7 mm. 
     
     
       12. The open-end spinning frame in accordance with  claim 1 , characterized in that one radial face of one of the annular shoulders forms a terminal end of the rotor shaft. 
     
     
       13. The open-end spinning frame in accordance with  claim 1 , characterized further by a mechanical emergency bearing in the end area of the rotor shaft, the emergency bearing having at least one bearing component made of a ceramic material. 
     
     
       14. The open-end spinning frame in accordance with  claim 13 , characterized in that the one bearing component comprises a ceramic pin. 
     
     
       15. The open-end spinning frame in accordance with  claim 14 , characterized in that the ceramic pin is fixed in a bore of a bearing bushing of the axial bearing. 
     
     
       16. The open-end spinning frame in accordance with  claim 14 , characterized in that the ceramic pin is fixed in a bore of the rotor shaft. 
     
     
       17. A rotor shaft for a spinning rotor of an open-end spinning frame, the rotor shaft comprising:
 a rotating magnetic bearing component arranged at an end area of the rotor shaft, the rotating magnetic bearing component comprising at least two ferromagnetic annular shoulders defined by adjacent recesses in the rotor shaft, each annular shoulder having opposed radial faces and a generally rounded outer circumference extending therebetween, and each recess having a base circumference connected via rounded annular surfaces with the radial faces of the adjacent annular shoulders.   
     
     
       18. The rotor shaft of claim 17, wherein the ratio of the length of the rotor shaft to the diameter of the rotor shaft is less than about 12:1. 
     
     
       19. The rotor shaft of claim 17, wherein the ratio of the length of the rotor shaft to the diameter of the rotor shaft is about 11.33:1. 
     
     
       20. The rotor shaft of claim 17, wherein the rotor shaft has a length of less than about 100 mm. 
     
     
       21. The rotor shaft of claim 17, wherein the rotor shaft has a length of about 93.5 mm. 
     
     
       22. The rotor shaft of claim 17, wherein the generally rounded outer circumference of each of the annular shoulders comprises curved annular sections extending between an exterior circumferential surface and the adjacent radial faces. 
     
     
       23. The rotor shaft of claim 22, wherein each of the curved sections in the area of the exterior circumferential surface has an axial dimension of between about 0.1 mm and about 0.5 mm. 
     
     
       24. The rotor shaft of claim 22, wherein each of the curved sections in the area of the exterior circumferential surface has an axial dimension of about 0.3 mm. 
     
     
       25. The rotor shaft of claim 17, wherein the generally rounded outer circumference of each of the annular shoulders comprises beveled annular sections extending between an exterior circumferential surface and the adjacent radial faces. 
     
     
       26. The rotor shaft of claim 17, wherein the rounded annular surfaces of each recess between the base circumference thereof and the radial faces of the adjacent annular shoulders have a dimension of between about 0.2 mm and about 1.5 mm. 
     
     
       27. The rotor shaft of claim 17, wherein the rounded annular surfaces of each recess between the base circumference thereof and the radial faces of the adjacent annular shoulders have a dimension of about 0.7 mm. 
     
     
       28. The rotor shaft of claim 17, wherein one radial face of one of the annular shoulders forms a terminal end of the rotor shaft. 
     
     
       29. The rotor shaft of claim 17, further comprising:
 a mechanical emergency bearing in the end area of the rotor shaft, the emergency bearing having at least one bearing component made of a ceramic material.   
     
     
       30. The rotor shaft of claim 29, wherein the at least one bearing component comprises a ceramic pin. 
     
     
       31. The rotor shaft of claim 30, wherein the ceramic pin is fixed in a bore of a bearing bushing of the axial bearing. 
     
     
       32. The rotor shaft of claim 30, wherein the ceramic pin is fixed in a bore of the rotor shaft. 
     
     
       33. A rotor shaft having a rotating bearing component arranged at an end thereof for use in a spinning frame in which the rotor shaft is coaxially fixed to a spinning rotor, a support disk bearing arrangement defines a bearing wedge for supporting the rotor shaft without imposing axial thrust thereon, a magnetic axial bearing having a bearing housing with a stationary magnetic bearing component fixed in the bearing housing, said rotating bearing component comprising at least two ferromagnetic annular shoulders defined by adjacent recesses in the rotor shaft, each annular shoulder having opposed radial faces and a generally rounded out circumference extending therebetween, and each recess having a base circumference connected with the radial faces of the adjacent annular shoulders. 
     
     
       34. The rotor shaft of claim 33, wherein each recess of said rotating bearing component has a rounded annular surface connecting said base circumference thereof with the radial faces of the adjacent annular shoulders. 
     
     
       35. The rotor shaft of claim 34, wherein the ratio of the length of the rotor shaft to the diameter of the rotor shaft is less than about 12:1. 
     
     
       36. The rotor shaft of claim 34, wherein the ratio of the length of the rotor shaft to the diameter of the rotor shaft is about 11.33:1. 
     
     
       37. The rotor shaft of claim 34, wherein the rotor shaft has a length of less than about 100 mm. 
     
     
       38. The rotor shaft of claim 34, wherein the rotor shaft has a length of about 93.5 mm. 
     
     
       39. The rotor shaft of claim 34, wherein the generally rounded outer circumference of each of the annular shoulders comprises curved annular sections extending between an exterior circumferential surface and the adjacent radial faces. 
     
     
       40. The rotor shaft of claim 39, wherein each of the curved sections in the area of the exterior circumferential surface has an axial dimension of between about 0.1 mm and about 0.5 mm. 
     
     
       41. The rotor shaft of claim 39, wherein each of the curved sections in the area of the exterior circumferential surface has an axial dimension of about 0.3 mm. 
     
     
       42. The rotor shaft of claim 34, wherein the generally rounded outer circumference of each of the annular shoulders comprises beveled annular sections extending between an exterior circumferential surface and the adjacent radial faces. 
     
     
       43. The rotor shaft of claim 34, wherein the rounded annular surfaces of each recess between the base circumference thereof and the radial faces of the adjacent annular shoulders have a dimension of between about 0.2 mm and about 1.5 mm. 
     
     
       44. The rotor shaft of claim 34, wherein the rounded annular surfaces of each recess between the base circumference thereof and the radial faces of the adjacent annular shoulders have a dimension of about 0.7 mm. 
     
     
       45. The rotor shaft of claim 34, wherein one radial face of one of the annular shoulders forms a terminal end of the rotor shaft. 
     
     
       46. The rotor shaft of claim 34, further comprising:
 a mechanical emergency bearing in the end area of the rotor shaft, the emergency bearing having at least one bearing component made of a ceramic material.   
     
     
       47. The rotor shaft of claim 46, wherein the at least one bearing component comprises a ceramic pin. 
     
     
       48. The rotor shaft of claim 47, wherein the ceramic pin is fixed in a bore of a bearing bushing of the axial bearing. 
     
     
       49. The rotor shaft of claim 47, wherein the ceramic pin is fixed in a bore of the rotor shaft. 
     
     
       50. A rotor shaft for a spinning rotor of an open-end spinning frame, the rotor shaft comprising:
 a rotating magnetic bearing component arranged at an end area of the rotor shaft, the rotating magnetic bearing component comprising at least two ferromagnetic annular shoulders defined by adjacent recesses in the rotor shaft, each annular shoulder having opposed radial faces and a generally rounded outer circumference extending therebetween, and each recess having a base circumference.   
     
     
       51. The rotor shaft of claim 50, wherein the ratio of the length of the rotor shaft to the diameter of the rotor shaft is less than about 12:1. 
     
     
       52. The rotor shaft of claim 50, wherein the ratio of the length of the rotor shaft to the diameter of the rotor shaft is about 11.33:1. 
     
     
       53. The rotor shaft of claim 50, wherein the rotor shaft has a length of less than about 100 mm. 
     
     
       54. The rotor shaft of claim 50, wherein the rotor shaft has a length of about 93.5 mm. 
     
     
       55. The rotor shaft of claim 50, wherein the generally rounded outer circumference of each of the annular shoulders comprises curved annular sections extending between an exterior circumferential surface and the adjacent radial faces. 
     
     
       56. The rotor shaft of claim 55, wherein each of the curved sections in the area of the exterior circumferential surface has an axial dimension of between about 0.1 mm and about 0.5 mm. 
     
     
       57. The rotor shaft of claim 55, wherein each of the curved sections in the area of the exterior circumferential surface has an axial dimension of about 0.3 mm. 
     
     
       58. The rotor shaft of claim 50, wherein the generally rounded outer circumference of each of the annular shoulders comprises beveled annular sections extending between an exterior circumferential surface and the adjacent radial faces. 
     
     
       59. The rotor shaft of claim 50, wherein the rounded annular surfaces of each recess between the base circumference thereof and the radial faces of the adjacent annular shoulders have a dimension of between about 0.2 mm and about 1.5 mm. 
     
     
       60. The rotor shaft of claim 50, wherein the rounded annular surfaces of each recess between the base circumference thereof and the radial faces of the adjacent annular shoulders have a dimension of about 0.7 mm. 
     
     
       61. The rotor shaft of claim 50, wherein one radial face of one of the annular shoulders forms a terminal end of the rotor shaft. 
     
     
       62. The rotor shaft of claim 50, further comprising:
 a mechanical emergency bearing in the end area of the rotor shaft, the emergency bearing having at least one bearing component made of a ceramic material.   
     
     
       63. The rotor shaft of claim 62, wherein the at least one bearing component comprises a ceramic pin. 
     
     
       64. The rotor shaft of claim 63, wherein the ceramic pin is fixed in a bore of a bearing bushing of the axial bearing. 
     
     
       65. The rotor shaft of claim 63, wherein the ceramic pin is fixed in a bore of the rotor shaft.