Title of Invention

BEARING ASSEMBLY FOR A SPINNING SPINDLE OF A RING SPINNING FRAME

Abstract

Bearing assembly for a spinning spindle of a ring spinning frame Bearing assembly for a spinning spindle of a ring spinning frame, in particular a radial bearing, with an outer bearing race (12; 32) that is connected to a support sleeve (7; 27) extending in axial direction and protrudes over it axially and with its inner face in ari axial area of the outer bearing race forming the bearing face (13; 33) for rollers (14; 34) arranged within the outer bearing race (12; 32), characterized in that the outer bearing race (12; 32) features a cylindrical extension (15; 35) that-axially joins the bearing face (13; 33) for the rollers (14; 34) and exhibits a wall thickness (w) that is smaller than two thirds of the wall thickness of the outer bearing race (12; 32) in the area of the bearing face (13; 33).

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] THE PATENTS RULES, 2003 as amended by THE PATENTS (AMENDMENT) RULES, 2006 COMPLETE SPECIFICATION [See Section 10; rule 13] "Bearing assembly for a spinning spindle of a ring spinning frame" HOLDING FUR INDUSTRIEBETEILIGUNGEN AG, of Bafflesstrasse 14, 9450 Altstatten, Switzerland The following specification particularly describes the invention and the manner in which it is to be performed: The present invention relates to a bearing assembly for a spinning spindle of a ring spinning frame. The invention relates to a bearing assembly for a spinning spindle on a ring spinning 5 frame in accordance with the preamble to Patent Claim 1. The process of converting natural and synthetic .fibres into yarn requires a series of working steps. The last working step in the process is normally referred to as fine spinning where the spun yarn acquires its final degree of finesse and strength. The 10 demands of fine spinning represent a substantial share of the entire yarn manufacturing process with regard to the time required, investments as well as the energy consumption. Ring spinning sufficiently known from the state of the art comes closest to classic hand spinning with spinning wheels. As on the classic spinning wheel, the spun yarn is wound onto a rotating spindle. Differing from the classic spinning wheel that features only one 15 spinning spindle rotating at a relatively slow speed, in the case of a ring spinning frame, a large number of spinning spindles, e.g. up to 500 and more, are arranged on a spindle bank, onto which the spun yarn is wound. In this case, the spinning spindles are rotated at speeds ranging from 10,000 to 25,000 revolutions per minute. 20 The spinning spindles normally used today feature an upper section, comprising a spindle stem, a drive wharve or whorl and a spindle top as well as a spindle housing that can be secured on a spindle bank and accept and supports the upper section of the spindle. The upper section of the spindle is supported by a radial spindle bolster or spindle collar that is normally designed as a roller bearing and a base bearing, normally 25 designed as a plain friction bearing, serving as a support and guide bearing. The spindle bolster is normally located in a rigid arrangement within the support sleeve in the spindle housing while the base bearing is arranged such that it can move radially in a guide sleeve. This guide sleeve is rigidly connected to the support sleeve at its end facing the spindle bolster and is designed in such a way that the base bearing can move radially. The 30 guide sleeve is normally formed as a steel tube that is weakened by indentations or 1502-8855 recesses running radially or helically in the area between the fastening in the support sleeve and the support of the base bearing in order to achieve the required degree of lateral resiliency or give. 5 The drive wharve concentrically encompasses the support sleeve holding the spindle bolster or spindle collar and is connected such that it turns with the spindle stem. The spinning spindles are driven by means of a drive belt that rests tangentially on the outer surface of the drive wharve. The spindle bolster is arranged approximately at the level of the drive belt in the area of the drive wharve and essentially takes up the radial forces 10 exerted by the drive belt. The diameter of the drive wharve has a direct influence on the force required for driving the spinning spindles. At a defined spindle speed, the drive belt as well as the tensioning pulley and idler pulley run faster the greater the diameter of the drive wharve. The smallest possible diameter of the drive wharve is determined by the outside diameter of the radial spindle bolster as well as the thickness of the support sleeve 15 wall that encompasses the spindle bolster. In turn, the outside diameter of the spindle bolster is determined by the bearing load expected during operation and which essentially depends on the weight of the rotating spindle upper section and its rotational speed. The weight of the spindle upper section is determined to a large extent by the size of the spindle top or cop, onto which the yarn is spun. The cop size is normally 20 standardized and is dependent on the further processing textile machines downstream. A very high spindle speed is aimed at, reaching a maximum of about 25,000 revolutions per minute in connection with today's standard cop formats. These marginal conditions define the load of the spindle bolster during operation, which in turn defines the 25 dimensioning, especially the outside diameter of the spindle bolster. DE-A-44 09 725 therefore describes how the roller bearings of the radial spindle bolster run directly on the inner surface of an extended, continuous, cylindrical outer bearing race. The section of the outer bearing race adjoining the bearing face for the rollers serves the purpose of fitting the radial bearing onto the spindle housing. The cylindrical outer race is normally 30 connected to the support sleeve by means of a press fit. The extended section of the outer 1502-8855 bearing race is either pressed over the end area or into the hole of the support sleeve. For strength reasons, the outer bearing race features a relatively large, uniform wall thickness over its entire extended length. The wall thickness is, however, a compromise between the \ required stability of the outer bearing race in the area of the rollers and the ductility of the 5 extended section necessary for press fitting the radial bearing. Unwanted deformation of j the inner surface of the outer bearing race can occur in the area of the rollers when press- [ fitting the radial bearing. This has a negative effect on the bearing quality, especially on \ the concentricity of the bearing and can impair the achievable maximum rotary speed of the spinning spindles. 10 The task of this invention is therefore to address these, in part, contradictory requirements and to redress the restrictions of state-of-the-art spinning spindles. The solution to this task is a spinning spindle for a ring spinning frame that exhibits the 1 5 sfjeatures outlined in the identified section of Patent Qaim 1. Further variants and/or advantageous versions of the invention are the subject of the dependent claims. A bearing assembly, designed in compliance with the invention, for a spinning spincue or a ring spinning frame, especially a radial bearing, comprises an outer bearing race that is 20 connected to a support housing that extends in axial direction and axially protrudes beyond this housing. The inner surface of the outer bearing race forms a bearing face for the rollers of the radial bearing. The outer bearing race features a cylindrical extension that extends in axial direction and which joins the bearing face for the rollers. The wall thickness of the cylindrical extension is less than two thirds of the wall thickness of the 25 outer bearing race in the area of the bearing face. The cylindrical extension adjoining the outer bearing race has a substantially smaller wall thickness than the outer bearing race in the area of the bearing face for the rollers. 1502-8855 Consequently, it is considerably easier to connect the extension to the support housing. During the press-fitting procedure, the cylindrical extension can be distorted to the required extent. This deformation, however, has no effect on the outer bearing race and the concentricity of the bearing face for the rollers. The bearing quality, concentricity and 5 the service life of the radial bearing are consequently substantially improved compared to the state of the art. This avoids a reduction in the achievable rotational speed of the spinning spindle as the result of poor concentricity. It proves advantageous when the wall thickness of the cylindrical extension is 10 approximately 3/5 to about 1/2 of the wall thickness of the outer bearing race in the area of the bearing face. These wall thickness conditions, on the one hand, facilitate mounting of the radial bearing on the support housing while, on the other hand, achieving the best possible stability of the outer bearing race in the area of the bearing face for the rollers. 15 In a variant of the invention, the cylindrical extension essentially has the same outside diameter as the outer bearing race in the area of the bearing face. The cylindrical extension is designed as one piece together with the outer bearing race. When fitted in position, the cylindrical extension protrudes over the support housing. The shoulder at the transition of the cylindrical extension to the outer bearing race with the greater wall thickness serves 20 as a limit stop for the end face of the support housing. In an alternative variant of the invention, the cylindrical extension can feature an inside diameter that is equal to or smaller than the inside diameter of the outer bearing race in the area of the bearing face. In this variant, the cylindrical extension is designed as an 25 insert section that is press-fitted into the hole of the support housing. An axial limit stop for the end face of the support housing is formed at the transition from the cylindrical extension to the outer bearing race featuring a greater wall thickness. 1502-8855 In an advantageous variant of the invention, the cylindrical extension features an inside diameter that is smaller than the inside diameter of the outer bearing race in the area of the bearing face. The resulting, annular shoulder serves as an axial support surface for a lower flanged ring of the radial bearing or itself forms an integrated flanged ring. 5 To ensure the most compact design of the bearing assembly it is appropriate that an axial end section of the support housing that directly joins the outer bearing race axially has the same outside diameter as the outer bearing race in the area of the bearing face. As a result, the inside diameter of the drive wharve can be optimised corresponding to the specified 10 dimension of the outside diameter of the outer bearing race. The section of the outer bearing race forming the bearing face is advantageously covered by a thin-walled, cylindrical ring extension. The correspondingly formed shoulder serves as a support surface for an upper flanged ring that joins the radial bearing and protects 15 against soiling. After fitting the upper flanged ring, the axial end section of the cylindrical ring extension is advantageously beaded or flanged in position so that the upper flanged ring is held captive. 20 In an advantageous variant of the invention, the bearing face for the rollers is hardened while the cylindrical extension and, if applicable, the ring extension are unhardened. This consequently ensures simple ductility of the cylindrical extension while mounting on the support housing and of the ring extension during the flanging process. On the other hand, 25 the bearing face subject to higher stress and strain features the highest degree or hardness. The rollers of the bearing assembly can feature cylindrical or slightly curved roller surfaces. The rollers are preferably designed as cylindrical bearing rollers. The largest contact surface of the cylindrical bearing rollers exhibits a higher resistance to wear. 1502-8855 With a spinning spindle inserted in the support housing, the drive wharve firmly connected such that it rotates with the spindle stem protrudes over the outer bearing race in such a way that a drive surface provided on the outer surface of the drive wharve for a 5 drive belt or similar runs approximately at the level of the bearing face for the rollers. The central contact of the drive belt in the area of the rollers ensures improved support while taking up tilt moments more effectively. Further advantages and features of the invention may be derived from the following 10 description of version examples of the bearing assembly for a spinning spindle. The drawings show in schematic representation and partly in axial sectional view: Fig. 1 A spinning spindle corresponding to the state of the art 15 Fig. 2 A first version example of a spinning spindle corresponding to the invention and Fig. 3 A second version example of the spinning spindle Fig. 1 shows a state-of-the-art spinning spindle 101 mounted in its operational position on 20 a spindle bank B of a ring spinning frame. For this purpose, a spindle housing 108 features a flange 116 and is secured to the spindle bank B by means of a fastening nut M that is screwed onto an external thread on spindle housing 108. Spindle housing 108 accommodates a support housing 109. A radial spindle bolster 110 is press-fitted into an end section designed as a roller bearing arranged above the spindle bank B. The spindle 25 bolster 110 exhibits a row of rollers 112 and is limited by a cylindrical outer race 111. The cylindrical outer race 111 is held by a press fit within the end section of the support housing 109. The support housing 109 encompasses and carries a guide sleeve 113 that is designed such that it gives laterally. For this purpose, the guide sleeve 113 that is 1502-8855 normally made of steel features helical recesses or indentations 114. At its end facing away from the spindle bolster 110, the guide sleeve 113 has a base bearing 115 that is normally designed as a plain friction bearing. 5 The spindle housing 108 carries a spindle top section 102 that encompasses a spindle stem 103, a drive wharve or whorl 104 and a spindle top 107. When the spinning spindle 101 is assembled, the spindle stem 103 is inserted in the spindle housing 108 where it is supported axially by the base bearing 115. The spindle stem 103 is supported radially by the rollers 112 of the spindle bolster 110. The drive wharve 104 is firmly 10 connected such it turns with the spindle stem 103 and encompasses the support housing 109 that protrudes axially over the spindle housing 108. The inner wall 106 of the drive wharve is located in the direct vicinity of the outer wall of the support housing 109. A drive belt that rotates the spinning spindle 101 rests tangentially on the outer surface 105 of the drive wharve 104. As can be seen from the schematic representation, the 15 outside diameter of the drive wharve is derived from the resulting dimensions for the required load bearing capacity of the spindle bolster 110 and the wall thickness of the support housing 109 with the spindle bolster 110 press-fitted into its end section. The spindle housing 108 is normally filled with oil that serves lubrication and damping 20 purposes. Further damping elements can be provided that, in combined action with the oil, dampen the lateral deflection of the spindle stem 103. A first version example of a spirining spindle corresponding to the invention represented schematically in its normal operating position in Fig. 2 has the overall reference symbol 1. 25 The in part sectional view is restricted to the constituent parts of the spinning spindle 1 necessary for clear comprehension. The figure additionally shows the constituent parts only on the left-hand side of a symmetry axis designated A. It is assumed as understood that the constituent parts are rotation-symmetrical parts that the expert observer will easily complete in identical form to the right of the symmetry axis A in the axial sectional 30 view. Apart from the differences explained in the following, the spinning spindle 1 exhibits the same principle design as the state-of-the-art spinning spindles presented in 1502-8855 Fig. 1. The spinning spindle 1 is shown together with assembled spindle upper section 2 and spindle housing 6. In turn, the spindle upper section 2 comprises a spindle stem 3 and a drive wharve 4 firmly connected to it such that it rotates. The spindle top is not shown in this schematic representation. 5 The spindle stem 3 is inserted in the spindle housing 6 and extends through a guide sleeve 10. The spindle stem is supported axially on a base bearing (not shown in Fig. 2) mounted on the guide sleeve 10. The base bearing is preferably designed as a plain friction bearing. The guide sleeve 10 is made of plastic, an oil-resistant PVC for instance. 10 The plastic guide sleeve 10 has an additional damping effect and facilitates smooth ninning of the spinning spindle 1. The guide sleeve 10 is designed such that it features lateral give at least in the area of the base bearing. The guide sleeve 10 is mounted in a support sleeve 7 that encompasses the guide sleeve 10 and protrudes in axial direction over the spindle housing 6 extended in a flange. An end section 8 of the support sleeve 7 15 bears a spindle bolster 11 that is preferably designed as a roller bearing. In Fig. 2 this is indicated by a roller 14 resting on the spindle stem 3. The spindle bolster 11 is limited radially by a cylindrical outer bearing race 12 that protrudes axially over the end section 8 of the support sleeve 7 and is firmly connected to 20 it such that it turns. The inner wall of the outer bearing race 12 forms a bearing face 13 for the rollers 14 of the radial spindle bolster 11. The bearing face 13 for the rollers 14 is preferably hardened. From the outer bearing race 12, a cylindrical extension 15 protrudes in the direction of the support sleeve 7 with a wall thickness w less than 2/3 of the wall thickness of the inner bearing race 12 in the area of the bearing face 13 for the rollers 14. 25 The wall thickness w of the cylindrical extension 15 is preferably approx. 3/5 to about 1/2 of the wall thickness of the outer bearing race 12. The length 1 of the cylindrical extension 15 is about one to five times the axial length of the bearing face 13. The cylindrical extension 15 serves the purpose of firmly securing the spindle bolster 11 at 30 the end section 8 of the support sleeve 7. In the version example shown in Fig. 2, the cylindrical extension 15 exhibits approximately the same outside diameter o as the outer 1502-8855 bearing race 12 in the area of the bearing face 13. The end section 8 of the support sleeve 7 features a reduced outside diameter compared to the rest of the housing. Consequently, the cylindrical extension 15 can be press-fitted over the end section 8 of the support sleeve 7. The cylindrical extension 15 then encompasses the end section 8 of the support 5 housing 7. The end face 9 of the support sleeve 7 is located within the cylindrical extension 15 in the vicinity of the transition from the cylindrical extension 15 to the bearing face 13 of the outer bearing race 12. A lower flanged ring 19 featuring a central hole is supported on the end face 9 of the end section 8 of the support sleeve 7 and bears the rollers 14 of the spindle bolster 11. 10 A ring extension 16 that features a distinctiy lower wall thickness than the outer bearing race 12 protrudes from the outer bearing race 12 on the side opposite the cylindrical extension 15. An upper flanged ring 18 featuring a central hole and which protects the spindle bolster 11 from soiling is supported on the resulting annular shoulder 17. The 1 5 annular free end of the ring extension 16 is beaded or flanged so that the flanged ring 18 is held captive. The further version example of the invention illustrated in Fig. 3 essentially corresponds to the version example from Fig. 2 and features the same components. They bear reference 20 symbols that are increased by a factor of 20 compared to Fig. 2. The essential differences are in the design of the end section 28 of the support sleeve 27 and of the spindle bolster 31. Again, a cylindrical extension 35 protrudes from the outer race 32 of the spindle bolster 31. Its wall thickness w is smaller than the wall thickness of the outer bearing race 32 in the area of the bearing face 33 for the rollers 34. As shown in the 25 illustrated version example, the cylindrical extension 35 exhibits an inside diameter i that is smaller than the inside diameter of the outer bearing race 32 measured at the bearing face 33. Correspondingly, the cylindrical extension 35 also features a smaller outside diameter than the outer bearing race 32 of the spindle bolster 32. The end section 28 of the support sleeve 27 has a reduced outside diameter. This makes it possible to press the 30 cylindrical extension 35 into the end section 28 of the support sleeve 27. A shoulder at the transition of the cylindrical extension 37 into the outer race 32 of the spindle bolster 32 1502-8855 facilitates mounting and cantering of the spindle bolster 31. The outer bearing race 32 of the spindle bolster 31 is again covered by a ring extension 36 with its free ring end beaded. An upper flanged ring 38 featuring a central hole joins the spindle bolster 31 within the ring extension 36. An annular shoulder 40 is formed at the transition from the inside diameter of the cylindrical extension 35 to the bearing face 33 of the outer bearing race. This shoulder serves as a support surface for a lower flanged ring or itself forms an integrated flanged ring that supports the bearing rollers 34. The outside dimensions of the support housing-spindle bolster unit are defined by the outside diameter of the outer bearing race of the spindle bolster. When assembled, the drive wharve, with the drive belt resting on its outer surface, is arranged with its inner face in the direct vicinity of the outer bearing race of the spindle bolster. As a result, the complete design of the spinning spindle is retained without having to make changes to the dimensions of the spindle bolster. The cylindrical extension protruding from the outer bearing race features a distinctly lower wall thickness than the outer bearing race. Consequently, it can deform to the required extent when pressing the spindle bolster onto the support sleeve. The deformation remains restricted to the cylindrical extension. The outer bearing race that has a comparatively greater wall thickness is not stressed or impaired so that the required concentricity of the bearing face for the rollers of the spindle bolster is retained. This has an advantageous effect on the running properties of the spinning spindle and on the service life of the spindle bolster. We claim: 1. Bearing assembly for a spinning spindle of a ring spinning frame, in particular a radial bearing, with an outer bearing race (12; 32) that is connected to a support sleeve (7; 27) extending in axial direction and protrudes over it axially and with its inner face in an axial area of the outer bearing race forming the bearing face (13; 33) for rollers (14; 34) arranged within the outer bearing race (12; 32), characterized in that the outer bearing race (12; 32) features a cylindrical extension (15; 35) that-axially joins the bearing face (13; 33) for the rollers (14; 34) and exhibits a wall thickness (w) that is smaller than two thirds of the wall thickness of the outer bearing race (12; 32) in the area of the bearing face (13; 33). 2. Bearing assembly as claimed in claim 1, wherein the wall thickness (w) of the cylindrical extension (15; 35) is 3/5 to 1/2 of the wall thickness of the outer bearing race (12; 32) in the area of the bearing face (13; 33). 3. Bearing assembly as claimed in claim 1 or 2, wherein the cylindrical extension (15) essentially has the same outside diameter (a) as the outer bearing race(12) in the area of the bearing face(13). 4. Bearing assembly as claimed in claim 1 or 2, wherein the cylindrical extension (35) exhibits an inside diameter (i) that is the same or smaller than the inside diameter of the outer bearing race (32) in the area of the bearing face (33). 5. Bearing assembly as claimed in claim 4, wherein the cylindrical extension (35) exhibits an inside diameter (i) that is smaller than the inside diameter of the outer beating race (32) in the area of the bearing face (33) and the resulting annular shoulder (40) serves as a support surface for a lower flanged ring or itself forms the flanged ring. 6. Bearing assembly as claimed in claim 4 or 5, wherein an axial end section (28) of the support sleeve (27) that directly joins the outer bearing race (32) essentially has the same outside diameter as the outer bearing race (32) in the area of the bearing face (33). 7. Bearing assembly as claimed in one of the previous claims wherein the section of the outer bearing race {12-, 32) forming the bearing face {13; 33) is covered by a thin-walled, cylindrical ring projection (16; 36) while forming a support surface for an upper flanged ring (18; 38). 8. Bearing assembly as claimed in claim 7, wherein the axial end section of the cylindrical ring extension (18; 38) is beaded in position. 9. Bearing assembly as claimed in any one of the previous claims, wherein the bearing face (13; 33) for the rollers (14; 34) is hardened. 10. Bearing assembly as claimed in any one of the previous claims, wherein a spinning spindle fitted in the spindle housing (6; 26) with its fixed drive wharve (4; 24) protrudes over the support sleeve (7; 27) in such a way that a drive face (5; 25) for a drive belt or similar provided on the outer surface of the drive wharve (4; 24) is arranged approximately at the level of the bearing face (13; 33) for the rollers (14; 34). 11. Bearing assembly for a spinning spindle of a ring spinning frame substantially as hereinbefore described with reference to the accompanying drawings. Dated this 30th day of January, 2003. [RAJAN AILAVADI] OF REMFRY & SAGAR ATPORNEY FOR THE APPLICANTS

Documents:

111-mum-2003-abstract(26-5-2008).doc

111-mum-2003-abstract(26-5-2008).pdf

111-mum-2003-cancelled pages(30-1-2003).pdf

111-mum-2003-claims(granted)-(26-5-2008).doc

111-mum-2003-claims(granted)-(26-5-2008).pdf

111-mum-2003-correspondence(26-5-2008).pdf

111-mum-2003-correspondence(ipo)-(21-2-2008).pdf

111-mum-2003-drawing(26-5-2008).pdf

111-mum-2003-form 1(26-5-2006).pdf

111-mum-2003-form 18(4-12-2006).pdf

111-mum-2003-form 2(granted)-(26-5-2008).doc

111-mum-2003-form 2(granted)-(26-5-2008).pdf

111-mum-2003-form 3(26-5-2008).pdf

111-mum-2003-form 3(3-4-2003).pdf

111-mum-2003-form 3(30-1-2003).pdf

111-mum-2003-form 5(26-5-2008).pdf

111-mum-2003-form-pct-isa-210(26-5-2008).pdf

111-mum-2003-power of authority(26-5-2008).pdf

111-mum-2003-power of authority(30-1-2003).pdf

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