Spinning Rotor for an Open-End Spinning Machine having a Friction-Enhancing Lining Made of an Elastomeric Material, and Open-End Spinning Machine

Abstract

A spinning rotor for an open-end spinning device includes a rotor shaft, via which the spinning rotor is driven with the aid of a belt. A contact area is on the rotor shaft for engagement with the belt. A friction coefficient-increasing lining made of an elastomeric material is applied along at least part of the contact area.

Claims

1-10. (canceled)

11. A spinning rotor for an open-end spinning device, the spinning rotor comprising: a rotor shaft, via which the spinning rotor is driven with the aid of a belt; a contact area on the rotor shaft for the belt; and a friction coefficient-increasing lining made of an elastomeric material along at least part of the contact area.

12. The spinning rotor as in claim 11, wherein the lining comprises an overall width (b) that is less than a width (B) of the belt provided for driving the spinning rotor.

13. The spinning rotor as in claim 11, wherein lining is applied onto the rotor shaft as multiple spaced-apart strips.

14. The spinning rotor as in claim 11, wherein the lining comprises a thickness (d) of 1 mm or less.

15. The spinning rotor as in claim 11, further comprising at least one recess formed in the rotor shaft in the contact area, the lining contained in the recess.

16. The spinning rotor as in claim 15, wherein the lining is co-planar with adjacent surfaces of the rotor shaft via grinding of the rotor shaft and lining.

17. The spinning rotor as in claim 11, wherein the fining is formed from nitrile rubber (NBR) or hydrogenated acrylonitrile butadiene rubber (HNBR).

18. The spinning rotor as in claim 11, wherein the lining is formed of a polyurethane elastomer (PUR).

19. The spinning rotor as in claim 11, wherein the rotor shaft is made of a metal.

20. An open-end spinning device comprising a spinning rotor and a driving belt, wherein the spinning rotor is in accordance with claim 11.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further advantages of the invention are described with reference to the exemplary embodiments represented in the following. Wherein:

[0017] FIG. 1 shows a schematic top view of an overview representation of an open-end spinning device comprising a rotor shaft and a belt for driving the rotor shaft;

[0018] FIG. 2 shows a detailed representation of a spinning rotor including a contact area for a belt;

[0019] FIG. 3 shows a partial cutaway view of one further embodiment of a spinning rotor comprising a friction coefficient-increasing lining; and

[0020] FIG. 4 shows a partial cutaway view of one further, alternative embodiment of a spinning rotor.

DETAILED DESCRIPTION

[0021] Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

[0022] FIG. 1 shows a schematic top view of an open-end spinning device 4 comprising a spinning rotor 1 and a belt 3 for driving the spinning rotor 1. In this case, the spinning rotor 1 usually consists of the rotor shaft 2 and a rotor cup 6, which can be removably as well as fixedly connected to the rotor shaft 2. The spinning device 4 includes, in the usual way, a bearing device for the spinning rotor 1, which is designed in the form of a support disk bearing in this case. Two support disk bearings 13, in each of which, in turn, a shaft 14 is mounted, are accommodated in a bearing block 12 for the radial support of the spinning rotor. Each of the two shafts 14 supports a support disk 10 at each of its two ends. The two shafts 14 comprising the support disks 10 are now situated in such a way that a wedge gap 9 forms between two support disks 10 in each case, in which the spinning rotor 1, including its rotor shaft 2, can be accommodated. The drive of the spinning rotor 1 takes place between the two resultant pairs of support disks with the aid of the belt 3 which tangentially contacts the rotor shaft 2, as in this case, or only slightly wraps around the rotor shaft 2.

[0023] During operation, the spinning rotor 1 rotates at speeds of 170,000 1/min and higher. In the case of a belt drive as described, considerable contact pressures are required in order to press the belt 3 against the rotor shaft 2 of the spinning rotor 1 and thereby transmit the motion of the belt 3 onto the spinning rotor 1 and make it possible to accelerate the spinning rotor 1 to the required speed. Due to these driving forces, however, the spinning rotor 1 is also pressed deeper into the wedge gap 9 of the support disks 10, and so, as the contact pressures increase, the deformation work in the lining of the support disks 10 also increases to a considerable extent. This results in an undesirably high temperature development in the lining of the support disks 10, which promotes an uneven running of the spinning rotor and wear of the support disks 10. In addition, this flexing work also results in considerable energy consumption in the mounting of the spinning rotor 1. On the other hand, slip occurs between the belt 3 and the rotor shaft 2, however, in particular during the ramping-up of the spinning rotor 1, which, over time, can result in considerable wear of the belt 3. As a result, the spinning rotors 1 can be accelerated only very slowly, for example, during piecing, or the required speed for the piecing, and possibly even the operating speed, cannot even be reached any more and, under certain circumstances, a faulty yarn is produced.

[0024] It is therefore proposed to provide the rotor shaft 2 of the spinning rotor 1 with an elastomeric, friction coefficient-increasing lining. FIG. 2 shows such a spinning rotor 1 which is provided with such a friction coefficient-increasing lining 8 in the contact area 7, i.e., the effective area of the drive belt 3. As a result, the friction coefficient between the belt 3 and the rotor shaft 2 is considerably improved or even doubled with respect to a conventional contact area, and so substantially lower contact pressures are required on the pressure roller (not shown) in order to reliably transmit the motion of the belt 3 onto the rotor shaft 2. Due to the reduced pressing force of the pressure roller, the spinning rotor 1 is also pressed into the wedge gap 9 of the support disks 10 to a lesser extent, which results in a considerable energy reduction due to the greatly reduced flexing work in the support disks 10. In addition, due to the reduced contact pressure of the belt 3 onto the rotor shaft 2, the radial load on the support disk bearings 13 is also reduced, and so the support disk bearings 13 are also subject to substantially less wear and require replacement less often. In addition, due to the improvement in the friction coefficient, the wear of the belt 3 is also reduced, whereby the belt 3 also has a substantially longer service life and, therefore, the amount of maintenance work can be further reduced.

[0025] According to the present example, the overall width b of the lining 8 is selected to be less than the width B of the belt 3 (see FIG. 1). As a result, on the one hand, the belt 3 can form a highly favorable friction coefficient pairing with the lining 8, although the belt 3 no longer rests, via its lateral edges 15 (see FIGS. 3 and 4), on the lining 8, but rather on the surrounding cylindrical surface of the rotor shaft 2. Premature wear of the lining 8 due to the abrasive edges 15 of the belt 3 can be avoided as a result, and so the service life of the spinning rotor 1 can also be improved. In the event of wear, however, the lining 8 can be replaced in a comparatively simple and cost-effective way. Moreover, the lining thickness d (see FIGS. 3 and 4) is relatively thin in this case, preferably having a lining thickness d of at most 0.3 mm, in order to avoid unfavorable flexing work in the lining 8.

[0026] FIG. 3 shows a partial cutaway view of a further embodiment of a spinning rotor 2, in the case of which the lining 8 is introduced, in the form of an insert, into a recess 5 of the rotor shaft 2. As is apparent in the figure, the lining 8 is introduced into the recess 5 in such a way that the lining 8 forms a smooth surface together with the surrounding cylindrical surface of the rotor shaft 2. The smooth, planar surface of the rotor shaft 2 in the area of the lining 8 and, in particular, at the transitions between the lining 8 and the cylindrical surface of the rotor shaft 2 can be produced, for example, via grinding. In this embodiment as well, the lining 8 is protected in a particularly favorable way against excess wear by the edges 15 of the belt 3. Nevertheless, a replacement of the lining 8 is also possible in a simple and cost-effective way in this case.

[0027] The lining thickness d or the depth of the recess 5 should be selected to be relatively small in this case as well, in particular, in a range of less than 1 mm, in order to avoid unfavorable influences on the characteristic frequency of the spinning rotor 1 and, therefore, undesirable oscillations.

[0028] Finally, FIG. 4 shows one further embodiment of a spinning rotor 1, in which the lining 8 is not applied continuously across the overall width b of the lining, but rather in the form of lining rings which are spaced apart from one another and, in combination, provide the overall width b of the lining 8. For this purpose, the rotor shaft 2 is provided with multiple interspaced recesses 5, in the form of circumferential grooves in this case, into each of which a lining ring has been introduced. In this embodiment as well, it is advantageous when the lining 8 is designed to have only a very small lining thickness d. A lining thickness d of less than 1 mm, or preferably only a few tenths of a millimeter, for example, at most 0.3 mm, is also advantageous in this case.

[0029] With the aid of the described lining 8, not only considerable energy savings can be achieved and the wear can be reduced. Due to the improved transmission of motion from the belt 3 onto the rotor shaft 2, the acceleration times for the spinning rotor 1 during piecing can also be considerably shortened, and so the machine efficiency is also improved as a result. Likewise, the operating speeds of the spinning rotor 1 can also be reached faster and more reliably, and they can be held constant. The improved embodiment of the spinning rotor 2 comprising a friction coefficient-increasing lining therefore also contributes to the production of a higher-quality yarn.

[0030] The invention is not limited to the exemplary embodiments which have been represented. Modifications and combinations within the scope of the claims are also covered by the invention.

LIST OF REFERENCE SIGNS

[0031] 1. spinning rotor

[0032] 2. rotor shaft

[0033] 3. belt

[0034] 4. open-end spinning device

[0035] 5. recess

[0036] 6. rotor cup

[0037] 7. contact area

[0038] 8. lining

[0039] 9. wedge gap

[0040] 10. support disk

[0041] 11. axial bearing

[0042] 12. bearing block

[0043] 13. support disk bearing

[0044] 14. shaft

[0045] 15. lateral edges of the belt

[0046] b overall width of the lining

[0047] B width of the belt

[0048] d lining thickness